Vibration energy harvesting based monitoring of an operational bridge undergoing forced vibration and train passage

NASA Astrophysics Data System (ADS)

Cahill, Paul; Hazra, Budhaditya; Karoumi, Raid; Mathewson, Alan; Pakrashi, Vikram

2018-06-01

The application of energy harvesting technology for monitoring civil infrastructure is a bourgeoning topic of interest. The ability of kinetic energy harvesters to scavenge ambient vibration energy can be useful for large civil infrastructure under operational conditions, particularly for bridge structures. The experimental integration of such harvesters with full scale structures and the subsequent use of the harvested energy directly for the purposes of structural health monitoring shows promise. This paper presents the first experimental deployment of piezoelectric vibration energy harvesting devices for monitoring a full-scale bridge undergoing forced dynamic vibrations under operational conditions using energy harvesting signatures against time. The calibration of the harvesters is presented, along with details of the host bridge structure and the dynamic assessment procedures. The measured responses of the harvesters from the tests are presented and the use the harvesters for the purposes of structural health monitoring (SHM) is investigated using empirical mode decomposition analysis, following a bespoke data cleaning approach. Finally, the use of sequential Karhunen Loeve transforms to detect train passages during the dynamic assessment is presented. This study is expected to further develop interest in energy-harvesting based monitoring of large infrastructure for both research and commercial purposes.

Civionics specifications for fiber optic sensors for structural health monitoring

NASA Astrophysics Data System (ADS)

Rivera, Evangeline; Mufti, Aftab A.; Thomson, Douglas J.

2004-07-01

As the design and construction of civil structures continue to evolve, it is becoming imperative that these structures be monitored for their health. In order to meet this need, the discipline of Civionics has emerged. It involves the applications to civil structures and aims to assist engineers in realizing the full benefits of structural health monitoring (SHM). Therefore, the goal of the specification outlined in this work is to ensure that correct installation and operating of fiber optic sensors, such as bridges, will be discussed that motivated the writing of these specifications. The main reason for the failure of FOS based monitoring systems can be traced directly to the installation of the fiber sensor itself. Therefore, by creating a standard procedure for SHM, several ambiguities are eliminated such as fiber sensor specifications and the types of cables required. As a result, these specifications will help ensure that the sensors will survive the installation process and eventually prove their value over years of monitoring the health of the structure. The Civionics FOS specifications include the requirements for fiber sensors, specifically Bragg grating sensors, and their corresponding readout unit. It also includes specifications on the cables, conduits, junction boxes, cable termination and the environmental.

Long-term real-time structural health monitoring using wireless smart sensor

NASA Astrophysics Data System (ADS)

Jang, Shinae; Mensah-Bonsu, Priscilla O.; Li, Jingcheng; Dahal, Sushil

2013-04-01

Improving the safety and security of civil infrastructure has become a critical issue for decades since it plays a central role in the economics and politics of a modern society. Structural health monitoring of civil infrastructure using wireless smart sensor network has emerged as a promising solution recently to increase structural reliability, enhance inspection quality, and reduce maintenance costs. Though hardware and software framework are well prepared for wireless smart sensors, the long-term real-time health monitoring strategy are still not available due to the lack of systematic interface. In this paper, the Imote2 smart sensor platform is employed, and a graphical user interface for the long-term real-time structural health monitoring has been developed based on Matlab for the Imote2 platform. This computer-aided engineering platform enables the control, visualization of measured data as well as safety alarm feature based on modal property fluctuation. A new decision making strategy to check the safety is also developed and integrated in this software. Laboratory validation of the computer aided engineering platform for the Imote2 on a truss bridge and a building structure has shown the potential of the interface for long-term real-time structural health monitoring.

Unmanned aerial vehicle acquisition of three-dimensional digital image correlation measurements for structural health monitoring of bridges

NASA Astrophysics Data System (ADS)

Reagan, Daniel; Sabato, Alessandro; Niezrecki, Christopher

2017-04-01

Civil engineering structures such as bridges, buildings, and tunnels continue to be used despite aging and deterioration well past their design life. In 2013, the American Society of Civil Engineers (ASCE) rated the state of the U.S. bridges as mediocre, despite the $12.8 billion USD annually invested. Traditional inspection and monitoring techniques may produce inconsistent results, are labor intensive and too time-consuming to be considered effective for large-scale monitoring. Therefore, new structural health monitoring systems must be developed that are automated, highly accurate, minimally invasive, and cost effective. Three-dimensional (3D) digital image correlation (DIC) systems possess the capability of extracting full-field strain, displacement, and geometry profiles. Furthermore, as this measurement technique is implemented within an Unmanned Aerial Vehicle (UAV) the capability to expedite the optical-based measurement process is increased as well as the infrastructure downtime being reduced. These resulting integrity maps of the structure of interest can be easily interpreted by trained personal. Within this paper, the feasibility of performing DIC measurements using a pair of cameras installed on a UAV is shown. Performance is validated with in-flight measurements. Also, full-field displacement monitoring, 3D measurement stitching, and 3D point-tracking techniques are employed in conjunction with 3D mapping and data management software. The results of these experiments show that the combination of autonomous flight with 3D DIC and other non-contact measurement systems provides a highly valuable and effective civil inspection platform.

A Review of Distributed Optical Fiber Sensors for Civil Engineering Applications.

PubMed

Barrias, António; Casas, Joan R; Villalba, Sergi

2016-05-23

The application of structural health monitoring (SHM) systems to civil engineering structures has been a developing studied and practiced topic, that has allowed for a better understanding of structures' conditions and increasingly lead to a more cost-effective management of those infrastructures. In this field, the use of fiber optic sensors has been studied, discussed and practiced with encouraging results. The possibility of understanding and monitor the distributed behavior of extensive stretches of critical structures it's an enormous advantage that distributed fiber optic sensing provides to SHM systems. In the past decade, several R & D studies have been performed with the goal of improving the knowledge and developing new techniques associated with the application of distributed optical fiber sensors (DOFS) in order to widen the range of applications of these sensors and also to obtain more correct and reliable data. This paper presents, after a brief introduction to the theoretical background of DOFS, the latest developments related with the improvement of these products by presenting a wide range of laboratory experiments as well as an extended review of their diverse applications in civil engineering structures.

An overview of wireless structural health monitoring for civil structures.

PubMed

Lynch, Jerome Peter

2007-02-15

Wireless monitoring has emerged in recent years as a promising technology that could greatly impact the field of structural monitoring and infrastructure asset management. This paper is a summary of research efforts that have resulted in the design of numerous wireless sensing unit prototypes explicitly intended for implementation in civil structures. Wireless sensing units integrate wireless communications and mobile computing with sensors to deliver a relatively inexpensive sensor platform. A key design feature of wireless sensing units is the collocation of computational power and sensors; the tight integration of computing with a wireless sensing unit provides sensors with the opportunity to self-interrogate measurement data. In particular, there is strong interest in using wireless sensing units to build structural health monitoring systems that interrogate structural data for signs of damage. After the hardware and the software designs of wireless sensing units are completed, the Alamosa Canyon Bridge in New Mexico is utilized to validate their accuracy and reliability. To improve the ability of low-cost wireless sensing units to detect the onset of structural damage, the wireless sensing unit paradigm is extended to include the capability to command actuators and active sensors.

A Review of Distributed Optical Fiber Sensors for Civil Engineering Applications

PubMed Central

Barrias, António; Casas, Joan R.; Villalba, Sergi

2016-01-01

The application of structural health monitoring (SHM) systems to civil engineering structures has been a developing studied and practiced topic, that has allowed for a better understanding of structures’ conditions and increasingly lead to a more cost-effective management of those infrastructures. In this field, the use of fiber optic sensors has been studied, discussed and practiced with encouraging results. The possibility of understanding and monitor the distributed behavior of extensive stretches of critical structures it’s an enormous advantage that distributed fiber optic sensing provides to SHM systems. In the past decade, several R & D studies have been performed with the goal of improving the knowledge and developing new techniques associated with the application of distributed optical fiber sensors (DOFS) in order to widen the range of applications of these sensors and also to obtain more correct and reliable data. This paper presents, after a brief introduction to the theoretical background of DOFS, the latest developments related with the improvement of these products by presenting a wide range of laboratory experiments as well as an extended review of their diverse applications in civil engineering structures. PMID:27223289

Vibration-based health monitoring and model refinement of civil engineering structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrar, C.R.; Doebling, S.W.

1997-10-01

Damage or fault detection, as determined by changes in the dynamic properties of structures, is a subject that has received considerable attention in the technical literature beginning approximately 30 years ago. The basic idea is that changes in the structure`s properties, primarily stiffness, will alter the dynamic properties of the structure such as resonant frequencies and mode shapes, and properties derived from these quantities such as modal-based flexibility. Recently, this technology has been investigated for applications to health monitoring of large civil engineering structures. This presentation will discuss such a study undertaken by engineers from New Mexico Sate University, Sandiamore » National Laboratory and Los Alamos National Laboratory. Experimental modal analyses were performed in an undamaged interstate highway bridge and immediately after four successively more severe damage cases were inflicted in the main girder of the structure. Results of these tests provide insight into the abilities of modal-based damage ID methods to identify damage and the current limitations of this technology. Closely related topics that will be discussed are the use of modal properties to validate computer models of the structure, the use of these computer models in the damage detection process, and the general lack of experimental investigation of large civil engineering structures.« less

Remote online monitoring and measuring system for civil engineering structures

NASA Astrophysics Data System (ADS)

Kujawińska, Malgorzata; Sitnik, Robert; Dymny, Grzegorz; Karaszewski, Maciej; Michoński, Kuba; Krzesłowski, Jakub; Mularczyk, Krzysztof; Bolewicki, Paweł

2009-06-01

In this paper a distributed intelligent system for civil engineering structures on-line measurement, remote monitoring, and data archiving is presented. The system consists of a set of optical, full-field displacement sensors connected to a controlling server. The server conducts measurements according to a list of scheduled tasks and stores the primary data or initial results in a remote centralized database. Simultaneously the server performs checks, ordered by the operator, which may in turn result with an alert or a specific action. The structure of whole system is analyzed along with the discussion on possible fields of application and the ways to provide a relevant security during data transport. Finally, a working implementation consisting of a fringe projection, geometrical moiré, digital image correlation and grating interferometry sensors and Oracle XE database is presented. The results from database utilized for on-line monitoring of a threshold value of strain for an exemplary area of interest at the engineering structure are presented and discussed.

Effects of temperature on bridge dynamic properties : final report.

DOT National Transportation Integrated Search

2015-12-01

Structural health monitoring (SHM) using ambient vibration has become a valuable tool in : evaluating and assessing the condition of civil structures. For bridge structures, a vibrationbased : SHM system uses the dynamic response of a bridge to measu...

Health monitoring of reinforced concrete structures based on PZT admittance signal

NASA Astrophysics Data System (ADS)

Wang, Dansheng; Zhu, Hongping; Shen, Danyan; Ge, Dongdong

2009-07-01

Reinforced concrete (RC) structure is one of most familiar engineering structure styles in the civil engineering community, which often suffer crack damage during their service life because of some factors such as overloading, excessive use, and bad environmental conditions. Thus early detection of crack damage is of special concern for RC structures. Piezoelectric materials have direct and converse piezoelectric effects and can serve as actuators or sensors. A health monitoring method based on PZT admittance signals is addressed in this paper, which use the electromechanical coupling property of piezoelectric materials. An experimental study on health monitoring of a RC beam is implemented based on the PZT admittance signals. In this experiment, the electrical admittances of distributed PZT sheets are measured when the host beams are suffering from variable loads. From the obtained PZT admittance curves one can find that the presence of incipient crack can be captured and the cracking load of the RC beam can also generally determined. By the experimental study it is concluded that the health monitoring technique is quite effective and sensitive for RC structures, which indicates its favorable application foreground in civil engineering field.

Built-in active sensing diagnostic system for civil infrastructure systems

NASA Astrophysics Data System (ADS)

Wu, Fan; Chang, Fu-Kuo

2001-07-01

A reliable, robust monitoring system can improve the maintenance of and provide safety protection for civil structures and therefore prolong their service lives. A built-in, active sensing diagnostic technique for civil structures has been under investigation. In this technique, piezoelectric materials are used as sensors/actuators to receive and generate signals. The transducers are embedded in reinforced concrete (RC) beams and are designed to detect damage, particularly debonding damage between the reinforcing bars and concrete. This paper presents preliminary results from a feasibility study of the technology. Laboratory experiments performed on RC beams, with piezo-electric sensors and actuators mounted on reinforced steel bars, have clearly demonstrated that the proposed technique could detect debonding damage. Analytical work, using a special purpose finite-element software, PZFlex, was also conducted to interpret the relationship between the measured data and actual debonding damage. Effectiveness of the proposed technique for detecting debonding damage in civil structures has been demonstrated.

Civil Society, Health, and Social Exclusion in Bangladesh

PubMed Central

Mahmud, Simeen

2009-01-01

Civil society has the potential to have a positive impact on social exclusion and health equity through active monitoring and increased accountability. This paper examines the role of civil society in Bangladesh to understand why this potential has not been realized. Looking at two models of civil society action—participation in decentralized public-sector service provision and academic think-tank data analysis—this analysis examines the barriers to positive civil society input into public policy decision-making. The role of non-governmental organizations, political, cultural and economic factors, and the influence of foreign bilateral and multilateral donors are considered. The paper concludes that, with a few exceptions, civil society in Bangladesh replicates the structural inequalities of society at large. PMID:19761087

42 CFR 423.2340 - Compliance monitoring and civil money penalties.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 3 2014-10-01 2014-10-01 false Compliance monitoring and civil money penalties... BENEFIT Medicare Coverage Gap Discount Program § 423.2340 Compliance monitoring and civil money penalties... Agreement. (b) Basis for imposing civil money penalties. CMS imposes a civil money penalty (CMP) on a...

42 CFR 423.2340 - Compliance monitoring and civil money penalties.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 3 2013-10-01 2013-10-01 false Compliance monitoring and civil money penalties... BENEFIT Medicare Coverage Gap Discount Program § 423.2340 Compliance monitoring and civil money penalties... Agreement. (b) Basis for imposing civil money penalties. CMS imposes a civil money penalty (CMP) on a...

Combining model based and data based techniques in a robust bridge health monitoring algorithm.

DOT National Transportation Integrated Search

2014-09-01

Structural Health Monitoring (SHM) aims to analyze civil, mechanical and aerospace systems in order to assess : incipient damage occurrence. In this project, we are concerned with the development of an algorithm within the : SHM paradigm for applicat...

Evaluation of uncertainty in determination of neutral axis and deformed shape of beam structures : final report.

DOT National Transportation Integrated Search

2016-01-01

With aging infrastructure, it becomes crucial to make informed decisions about maintenance and : preservation actions, as well as renewal of civil structures. Structural Health Monitoring (SHM) can be : an important aid in this decision process, but ...

Health monitoring with optical fiber sensors: from human body to civil structures

NASA Astrophysics Data System (ADS)

Pinet, Éric; Hamel, Caroline; Glišić, Branko; Inaudi, Daniele; Miron, Nicolae

2007-04-01

Although structural health monitoring and patient monitoring may benefit from the unique advantages of optical fiber sensors (OFS) such as electromagnetic interferences (EMI) immunity, sensor small size and long term reliability, both applications are facing different realities. This paper presents, with practical examples, several OFS technologies ranging from single-point to distributed sensors used to address the health monitoring challenges in medical and in civil engineering fields. OFS for medical applications are single-point, measuring mainly vital parameters such as pressure or temperature. In the intra-aortic balloon pumping (IABP) therapy, a miniature OFS can monitor in situ aortic blood pressure to trigger catheter balloon inflation/deflation in counter-pulsation with heartbeats. Similar sensors reliably monitor the intracranial pressure (ICP) of critical care patients, even during surgical interventions or examinations under medical resonance imaging (MRI). Temperature OFS are also the ideal monitoring solution for such harsh environments. Most of OFS for structural health monitoring are distributed or have long gage length, although quasi-distributed short gage sensors are also used. Those sensors measure mainly strain/load, temperature, pressure and elongation. SOFO type deformation sensors were used to monitor and secure the Bolshoi Moskvoretskiy Bridge in Moscow. Safety of Plavinu dam built on clay and sand in Latvia was increased by monitoring bitumen joints displacement and temperature changes using SMARTape and Temperature Sensitive Cable read with DiTeSt unit. A similar solution was used for monitoring a pipeline built in an unstable area near Rimini in Italy.

Intelligent structural health monitoring of vehicular bridges using fiber optic sensors to detect acoustic emission.

DOT National Transportation Integrated Search

2011-01-28

The recent collapse of the I-35W Mississippi River Bridge in Minneapolis has spawned a growing : interest in the development of reliable techniques for evaluating the structural integrity of civil : infrastructure. Current inspection techniques tailo...

Self-monitoring fiber reinforced polymer strengthening system for civil engineering infrastructures

NASA Astrophysics Data System (ADS)

Jiang, Guoliang; Dawood, Mina; Peters, Kara; Rizkalla, Sami

2008-03-01

Fiber reinforced polymer (FRP) materials are currently used for strengthening civil engineering infrastructures. The strengthening system is dependant on the bond characteristics of the FRP to the external surface of the structure to be effective in resisting the applied loads. This paper presents an innovative self-monitoring FRP strengthening system. The system consists of two components which can be embedded in FRP materials to monitor the global and local behavior of the strengthened structure respectively. The first component of the system is designed to evaluate the applied load acting on a structure based on elongation of the FRP layer along the entire span of the structure. Success of the global system has been demonstrated using a full-scale prestressed concrete bridge girder which was loaded up to failure. The test results indicate that this type of sensor can be used to accurately determine the load prior to failure within 15 percent of the measured value. The second sensor component consists of fiber Bragg grating sensors. The sensors were used to monitor the behavior of steel double-lap shear splices tested under tensile loading up to failure. The measurements were used to identify abnormal structural behavior such as epoxy cracking and FRP debonding. Test results were also compared to numerical values obtained from a three dimensional shear-lag model which was developed to predict the sensor response.

Safety monitoring of the FBG sensor in respect of radioactivity and deformation measurement of a silo structure for radioactive waste disposal

NASA Astrophysics Data System (ADS)

Kim, Ki-Soo; Cho, Seong-Kyu

2015-07-01

The FBG sensor has globally been commercialized in various fields that is actively applied in Korea as well. Especially it is widely used as a structural monitoring sensor in civil engineering and construction structures due to its advantages including electrical stability, chemical stability and multiplexing. This report aims to introduce safety inspection of the FBG sensor in respect of radioactivity which has been applied to a silo structure for radioactive waste disposal as an example.

Global Positioning System (GPS) civil signal monitoring (CSM) trade study report

DOT National Transportation Integrated Search

2014-03-07

This GPS Civil Signal Monitoring (CSM) Trade Study has been performed at the direction of DOT/FAA Navigation Programs as the agency of reference for consolidating civil monitoring requirements on the Global Positioning System (GPS). The objective of ...

Image-based dynamic deformation monitoring of civil engineering structures from long ranges

NASA Astrophysics Data System (ADS)

Ehrhart, Matthias; Lienhart, Werner

2015-02-01

In this paper, we report on the vibration and displacement monitoring of civil engineering structures using a state of the art image assisted total station (IATS) and passive target markings. By utilizing the telescope camera of the total station, it is possible to capture video streams in real time with 10fps and an angular resolution of approximately 2″/px. Due to the high angular resolution resulting from the 30x optical magnification of the telescope, large distances to the object to be monitored are possible. The laser distance measurement unit integrated in the total station allows to precisely set the camera's focus position and to relate the angular quantities gained from image processing to units of length. To accurately measure the vibrations and displacements of civil engineering structures, we use circular target markings rigidly attached to the object. The computation of the targets' centers is performed by a least squares adjustment of an ellipse according to the Gauß-Helmert model from which the parameters of the ellipse and their standard deviations are derived. In laboratory experiments, we show that movements can be detected with an accuracy of better than 0.2mm for single frames and distances up to 30m. For static applications, where many video frames can be averaged, accuracies of better than 0.05mm are possible. In a field test on a life-size footbridge, we compare the vibrations measured by the IATS to reference values derived from accelerometer measurements.

CNT-cement based composites: fabrication, self-sensing properties, and prospective applications to structural health monitoring

NASA Astrophysics Data System (ADS)

Rainieri, Carlo; Song, Yi; Fabbrocino, Giovanni; Schulz, Mark J.; Shanov, Vesselin

2013-08-01

Degradation phenomena can affect civil structures over their lifespan. The recent advances in nanotechnology and sensing allow to monitor the behaviour of a structure, assess its performance and identify damage at an early stage. Thus, maintenance actions can be carried out in a timely manner, improving structural reliability and safety. Structural Health Monitoring (SHM) is traditionally performed at a global level, with a limited number of sensors distributed over a relatively large area of a structure. Thus, only major damage conditions are detectable. Dense sensor networks and innovative structural neural systems, reproducing the structure and the function of the human nervous system, may overcome this drawback of current SHM systems. Miniaturization and embedment are key requirements for successful implementation of structural neural systems. Carbon nanotubes (CNTs) can play an attractive role in the development of embedded sensors and smart structural materials, since they can provide to traditional cement based materials both structural capability and measurable response to applied stresses, strains, cracks and other flaws. In this paper investigations about CNT/cement composites and their self-sensing capabilities are summarized and critically revised. The analysis of available experimental results and theoretical developments provides useful design criteria for the fabrication of CNT/cement composites optimized for SHM applications in civil engineering. Specific attention is paid to the opportunities provided by new RF plasma technologies for the functionalization of CNTs in view of sensor development and SHM applications.

Decentralized System Identification Using Stochastic Subspace Identification for Wireless Sensor Networks

PubMed Central

Cho, Soojin; Park, Jong-Woong; Sim, Sung-Han

2015-01-01

Wireless sensor networks (WSNs) facilitate a new paradigm to structural identification and monitoring for civil infrastructure. Conventional structural monitoring systems based on wired sensors and centralized data acquisition systems are costly for installation as well as maintenance. WSNs have emerged as a technology that can overcome such difficulties, making deployment of a dense array of sensors on large civil structures both feasible and economical. However, as opposed to wired sensor networks in which centralized data acquisition and processing is common practice, WSNs require decentralized computing algorithms to reduce data transmission due to the limitation associated with wireless communication. In this paper, the stochastic subspace identification (SSI) technique is selected for system identification, and SSI-based decentralized system identification (SDSI) is proposed to be implemented in a WSN composed of Imote2 wireless sensors that measure acceleration. The SDSI is tightly scheduled in the hierarchical WSN, and its performance is experimentally verified in a laboratory test using a 5-story shear building model. PMID:25856325

Integrated structural health monitoring

NASA Astrophysics Data System (ADS)

Farrar, Charles R.; Sohn, Hoon; Fugate, Michael L.; Czarnecki, Jerry J.

2001-07-01

Structural health monitoring is the implementation of a damage detection strategy for aerospace, civil and mechanical engineering infrastructure. Typical damage experienced by this infrastructure might be the development of fatigue cracks, degradation of structural connections, or bearing wear in rotating machinery. The goal of the research effort reported herein is to develop a robust and cost-effective structural health monitoring solution by integrating and extending technologies from various engineering and information technology disciplines. It is the author's opinion that all structural health monitoring systems must be application specific. Therefore, a specific application, monitoring welded moment resisting steel frame connections in structures subjected to seismic excitation, is described along with the motivation for choosing this application. The structural health monitoring solution for this application will integrate structural dynamics, wireless data acquisition, local actuation, micro-electromechanical systems (MEMS) technology, and statistical pattern recognition algorithms. The proposed system is based on an assessment of the deficiencies associated with many current structural health monitoring technologies including past efforts by the authors. This paper provides an example of the integrated approach to structural health monitoring being undertaken at Los Alamos National Laboratory and summarizes progress to date on various aspects of the technology development.

42 CFR 423.2340 - Compliance monitoring and civil money penalties.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 3 2012-10-01 2012-10-01 false Compliance monitoring and civil money penalties. 423.2340 Section 423.2340 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH... BENEFIT Medicare Coverage Gap Discount Program § 423.2340 Compliance monitoring and civil money penalties...

Application of fiber-Bragg-grating-based strain sensors for civil infrastructure health monitoring

NASA Astrophysics Data System (ADS)

Tjin, Swee C.; Rupali, S.; Moyo, Pilate; Brownjohn, James M. W.; Ngo, Nam Quoc

2003-10-01

Over past few years, the concept of structural health monitoring has been emerging as a new area of research. Fiber Bragg grating (FBG) based sensor offers a new sensing approach with a number of advantages over conventional sensors. This new sensing technology is suitable for the harsh environment of construction industry due to its robustness, ruggedness and ease of installation. Two unique advantages of FBG based sensors are immunity to electromagnetic interference and multiplexing capability. This paper reports some of the results of a multi-disciplinary program on the FBG based sensors involving the School of Electrical and Electronic Engineering and the School of Civil and Environment Engineering at Nanyang Technological University, Singapore.

An autonomous structural health monitoring system for Waiau interchange.

DOT National Transportation Integrated Search

2013-03-01

Bridge infrastructure is a critical element of the transportation system which makes maintaining its safety and : performance vital to a healthy society. However, the civil infrastructure systems in the United States are decaying : at an accelerated ...

GPS Civil Monitoring Performance Specification

DOT National Transportation Integrated Search

2009-02-10

This Civil Monitoring Performance Specification (CMPS) is published and maintained at : the direction of the Program Manager for Civil Applications, Global Positioning Systems : Wing (GPSW). The purpose of this document is to provide a comprehensive ...

Mass and stiffness estimation using mobile devices for structural health monitoring

NASA Astrophysics Data System (ADS)

Le, Viet; Yu, Tzuyang

2015-04-01

In the structural health monitoring (SHM) of civil infrastructure, dynamic methods using mass, damping, and stiffness for characterizing structural health have been a traditional and widely used approach. Changes in these system parameters over time indicate the progress of structural degradation or deterioration. In these methods, capability of predicting system parameters is essential to their success. In this paper, research work on the development of a dynamic SHM method based on perturbation analysis is reported. The concept is to use externally applied mass to perturb an unknown system and measure the natural frequency of the system. Derived theoretical expressions for mass and stiffness prediction are experimentally verified by a building model. Dynamic responses of the building model perturbed by various masses in free vibration were experimentally measured by a mobile device (cell phone) to extract the natural frequency of the building model. Single-degreeof- freedom (SDOF) modeling approach was adopted for the sake of using a cell phone. From the experimental result, it is shown that the percentage error of predicted mass increases when the mass ratio increases, while the percentage error of predicted stiffness decreases when the mass ratio increases. This work also demonstrated the potential use of mobile devices in the health monitoring of civil infrastructure.

Etched optical fiber vibration sensor to monitor health condition of beam like structures

NASA Astrophysics Data System (ADS)

Putha, Kishore; Dantala, Dinakar; Kamineni, Srimannarayana; Pachava, Vengal Rao

2013-06-01

Using a center etched single mode optical fiber, a simple vibration senor is designed to monitor the vibrations of a simply supported beam. The sensor has high linear response to the axial displacement of about 0.8 mm with a sensitivity of 32 mV/10 μm strain. The sensor is tested for periodic and suddenly released forces, and the results are found to coincide with the theoretical values. This simple design, small in size and low cost sensor may find applications in industry and civil engineering to monitor the vibrations of the beam structures and bridges.

Global positioning system (GPS) civil monitoring performance specification.

DOT National Transportation Integrated Search

2009-04-30

This Civil Monitoring Performance Specification (CMPS) is published and maintained at : the direction of the Program Manager for Civil Applications, Global Positioning Systems : Wing (GPSW). The purpose of this document is to provide a comprehensive ...

A study of reusable electromechanical impedance methods for structural health monitoring of civil structures

NASA Astrophysics Data System (ADS)

Tawie, R.; Na, S.; Lee, H. K.

2013-04-01

Up to date, various studies have been conducted using electro-mechanical impedance (EMI) method on concrete, including monitoring the strength development or to find damage in the structure. Since EMI method utilizes a single piezoelectric material to be used as an actuator and a sensor simultaneously, the method has major advantages compared to other non-destructive testing methods. However the method requires a piezoelectric material to be permanently attached or embedded into a structure. Thus when monitoring multiple structures, the method may become quite expensive. In this study, two re-usable EMI methods conducted by researchers Na et al and Tawie et al are overviewed. The idea of re-usable EMI method is still relatively new, resulting in the reduction of monitoring costs since the same piezoelectric material is used as many times as possible, while ensuring better repeatability and reliability in measurements.

Fiber-optic sensor applications in civil and geotechnical engineering

NASA Astrophysics Data System (ADS)

Habel, Wolfgang R.; Krebber, Katerina

2011-09-01

Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic sensors have been established as a new and innovative measurement technology in very different fields, such as material science, civil engineering, light-weight structures, geotechnical areas as well as chemical and high-voltage substations. Very often, mechanical quantities such as deformation, strain or vibration are requested. However, measurement of chemical quantities in materials and structure components, such as pH value in steel reinforced concrete members also provides information about the integrity of concrete structures. A special fiber-optic chemical sensor for monitoring the alkaline state (pH value) of the cementitious matrix in steel-reinforced concrete structures with the purpose of early detection of corrosion-initiating factors is described. The paper presents the use of several fiber-optic sensor technologies in engineering. One example concerns the use of highly resolving concrete-embeddable fiber Fabry-Perot acoustic emission (AE) sensors for the assessment of the bearing behaviour of large concrete piles in existing foundations or during and after its installation. Another example concerns fiber Bragg grating (FBG) sensors attached to anchor steels (micro piles) to measure the strain distribution in loaded soil anchors. Polymer optical fibers (POF) can be — because of their high elasticity and high ultimate strain — well integrated into textiles to monitor their deformation behaviour. Such "intelligent" textiles are capable of monitoring displacement of soil or slopes, critical mechanical deformation in geotechnical structures (dikes, dams, and embankments) as well as in masonry structures during and after earthquakes.

Structural health monitoring and damage evaluation for steel confined reinforced concrete column using the acoustic emission technique

NASA Astrophysics Data System (ADS)

Du, Fangzhu; Li, Dongsheng

2018-03-01

As a new kind of composite structures, the using of steel confined reinforced concrete column attract increasing attention in civil engineer. During the damage process, this new structure offers highly complex and invisible failure mechanism due to the combination effects of steel tubes, concrete, and steel rebar. Acoustic emission (AE) technique has been extensively studied in nondestructive testing (NDT) and is currently applied in civil engineering for structural health monitoring (SHM) and damage evaluation. In the present study, damage property and failure evolution of steel confined and unconfined reinforced concrete (RC) columns are investigated under quasi-static loading through (AE) signal. Significantly improved loading capacity and excellent energy dissipation characteristic demonstrated the practicality of that proposed structure. AE monitoring results indicated that the progressive deformation of the test specimens occur in three stages representing different damage conditions. Sentry function compares the logarithm ratio between the stored strain energy (Es) and the released acoustic energy (Ea); explicitly disclose the damage growth and failure mechanism of the test specimens. Other extended AE features including index of damage (ID), and relax ratio are calculated to quantitatively evaluate the damage severity and critical point. Complicated temporal evolution of different AE features confirms the potential importance of integrated analysis of two or more parameters. The proposed multi-indicators analysis is capable of revealing the damage growth and failure mechanism for steel confined RC columns, and providing critical warning information for structure failure.

Wireless technologies for the monitoring of strategic civil infrastructures: an ambient vibration test of the Faith Bridge, Istanbul, Turkey

NASA Astrophysics Data System (ADS)

Picozzi, M.; Milkereit, C.; Zulfikar, C.; Ditommaso, R.; Erdik, M.; Safak, E.; Fleming, K.; Ozel, O.; Zschau, J.; Apaydin, N.

2008-12-01

The monitoring of strategic civil infrastructures to ensure their structural integrity is a task of major importance, especially in earthquake-prone areas. Classical approaches to such monitoring are based on visual inspections and the use of wired systems. While the former has the drawback that the structure is only superficially examined and discontinuously in time, wired systems are relatively expensive and time consuming to install. Today, however, wireless systems represent an advanced, easily installed and operated tool to be used for monitoring purposes, resulting in a wide and interesting range of possible applications. Within the framework of the earthquake early warning projects SAFER (Seismic eArly warning For EuRope) and EDIM (Earthquake Disaster Information systems for the Marmara Sea region, Turkey), new low-cost wireless sensors with the capability to automatically rearrange their communications scheme are being developed. The reduced sensitivity of these sensors, arising from the use of low-cost components, is compensated by the possibility of deploying high-density self-organizing networks performing real-time data acquisition and analysis. Thanks to the developed system's versatility, it has been possible to perform an experimental ambient vibration test with a network of 24 sensors on the Fatih Sultan Mehmet Bridge, Istanbul (Turkey), a gravity-anchored suspension bridge spanning the Bosphorus Strait with distance between its towers of 1090 m. Preliminary analysis of the data has demonstrated that the main modal properties of the bridge can be retrieved, and may therefore be regularly re-evaluated as part of a long-term monitoring program. Using a multi-hop communications technique, data could be exchanged among groups of sensors over distances of a few hundred meters. Thus, the test showed that, although more work is required to optimize the communication parameters, the performance of the network offers encouragement for us to follow this research direction in developing wireless systems for the monitoring of civil infrastructures.

Effective Sealing and Monitoring of Small Movement Expansion Joints in Connecticut Bridges

DOT National Transportation Integrated Search

2017-03-01

One in nine bridges in the United States is rated as structurally deficient by the 2013 Infrastructure Report Card published by the American Society of Civil Engineers. One of the primary degradation factors that contribute to compromising the struct...

SHARD - a SeisComP3 module for Structural Health Monitoring

NASA Astrophysics Data System (ADS)

Weber, B.; Becker, J.; Ellguth, E.; Henneberger, R.; Herrnkind, S.; Roessler, D.

2016-12-01

Monitoring building and structure response to strong earthquake ground shaking or human-induced vibrations in real-time forms the backbone of modern structural health monitoring (SHM). The continuous data transmission, processing and analysis reduces drastically the time decision makers need to plan for appropriate response to possible damages of high-priority buildings and structures. SHARD is a web browser based module using the SeisComp3 framework to monitor the structural health of buildings and other structures by calculating standard engineering seismology parameters and checking their exceedance in real-time. Thresholds can be defined, e.g. compliant with national building codes (IBC2000, DIN4149 or EC8), for PGA/PGV/PGD, response spectra and drift ratios. In case thresholds are exceeded automatic or operator driven reports are generated and send to the decision makers. SHARD also determines waveform quality in terms of data delay and variance to report sensor status. SHARD is the perfect tool for civil protection to monitor simultaneously multiple city-wide critical infrastructure as hospitals, schools, governmental buildings and structures as bridges, dams and power substations.

Soldiers and Statesmen: Civil Military Case Studies of the NATO Decision-Making Process.

DTIC Science & Technology

1998-06-01

5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000 8. PERFORMING... ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/ MONITORING AGENCY REPORT NUMBER 11. SUPPLEMENTARY...ABSTRACT (maximum 200 words) The North Atlantic Treaty Organization was organized on a two-track structure. The military part of the Alliance was to be

DIAPHANE: muon tomography applied to volcanoes, civil engineering, archaelogy

NASA Astrophysics Data System (ADS)

Marteau, J.; de Bremond d'Ars, J.; Gibert, D.; Jourde, K.; Ianigro, J.-C.; Carlus, B.

2017-02-01

Muography techniques applied to geological structures greatly improved in the past ten years. Recent applications demonstrate the interest of the method not only to perform structural imaging but also to monitor the dynamics of inner movements like magma ascent inside volcanoes or density variations in hydrothermal systems. Muography time-resolution has been studied thanks to dedicated experiments, e.g. in a water tower tank. This paper presents the activities of the DIAPHANE collaboration between particle- and geo-physicists and the most recent results obtained in the field of volcanology, with a focus on the main target, the Soufrière of Guadeloupe active volcano. Special emphasis is given on the monitoring of the dome's inner volumes opacity variations, that could be ascribed to the hydrothermal system dynamics (vaporization of inner liquid water in coincidence with the appearance of new fumaroles at the summit). I also briefly present results obtained in the fields of civil engineering (study of urban underground tunnels) and archaelogy (greek tumulus scanning).

In-situ health monitoring of piezoelectric sensors using electromechanical impedance: A numerical perspective

NASA Astrophysics Data System (ADS)

Bilgunde, Prathamesh N.; Bond, Leonard J.

2018-04-01

Current work presents a numerical investigation to classify the in-situ health of the piezoelectric sensors deployed for structural health monitoring (SHM) of large civil, aircraft and automotive structures. The methodology proposed in this work attempts to model the in-homogeneities in the adhesive with which typically the sensor is bonded to the structure for SHM. It was found that weakening of the bond state causes reduction in the resonance frequency of the structure and eventually approaches the resonance characteristics of a piezoelectric material under traction-free boundary conditions. These changes in the resonance spectrum are further quantified using root mean square deviation-based damage index. Results demonstrate that the electromechanical impedance method can be used to monitor structural integrity of the sensor bonded to the host structure. This cost-effective method can potentially reduce misinterpretation of SHM data for critical infrastructures.

Compressive Membrane Capability Estimates in Laterally Edge Restrained Reinforced Concrete One-Way Slabs

DTIC Science & Technology

1999-05-01

by THE UNITED STATES ARMY, I DEPARTMENT OF CIVIL AND MECHANICAL ENGINEERINGI UNITED STATES MILITARY ACADEMY and DEPARTMENT OF CIVIL AND ENVIRONMENTAL ...SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING I MONITORING AG-ENCY REPORT NUMBER Department of Civil and Environmental ...LATERALLY EDGE RESTRAINED REINFORCED CONCRETE ONE-WAY SLABS Ronald Wayne Welch, Ph.D. Department of Civil and Environmental Engineering University of

Centralized remote structural monitoring and management of real-time data

NASA Astrophysics Data System (ADS)

Han, Liting; Newhook, John P.; Mufti, Aftab A.

2004-07-01

Structural health monitoring (SHM) activities in civil engineering are increasing at a rapid pace in both research and field applications. This paper addresses the specific issue of incorporating internet technology into a structural health monitoring program. The issue of data volume versus communication speed is discussed along with a practical solution employed by ISIS Canada. The approach is illustrated through reference to several current case studies which include two bridges and a statue. It is seen that although the specifics of the projects and monitoring needs are different, the manner in which on-line monitoring can be conducted is very similar and easily allows for centralized monitoring. A general framework for website construction integrating sensing data and web camera options are presented. Issues related to simple real-time performance indices versus more comprehensive complex data analysis are discussed. Examples of on-line websites which allow visualization of new and historic data are presented. The paper also discusses future activities and research needs related to centralized remote structural monitoring and management of real-time data.

Statistical analysis of modal properties of a cable-stayed bridge through long-term structural health monitoring with wireless smart sensor networks

NASA Astrophysics Data System (ADS)

Asadollahi, Parisa; Li, Jian

2016-04-01

Understanding the dynamic behavior of complex structures such as long-span bridges requires dense deployment of sensors. Traditional wired sensor systems are generally expensive and time-consuming to install due to cabling. With wireless communication and on-board computation capabilities, wireless smart sensor networks have the advantages of being low cost, easy to deploy and maintain and therefore facilitate dense instrumentation for structural health monitoring. A long-term monitoring project was recently carried out for a cable-stayed bridge in South Korea with a dense array of 113 smart sensors, which feature the world's largest wireless smart sensor network for civil structural monitoring. This paper presents a comprehensive statistical analysis of the modal properties including natural frequencies, damping ratios and mode shapes of the monitored cable-stayed bridge. Data analyzed in this paper is composed of structural vibration signals monitored during a 12-month period under ambient excitations. The correlation between environmental temperature and the modal frequencies is also investigated. The results showed the long-term statistical structural behavior of the bridge, which serves as the basis for Bayesian statistical updating for the numerical model.

Sequential Analysis: Hypothesis Testing and Changepoint Detection

DTIC Science & Technology

2014-07-11

it is necessary to estimate in situ the geographical coordinates and other parameters of earthquakes . The standard sensor equipment of a three...components. When an earthquake arises, the sensors begin to record several types of seismic waves (body and surface waves), among which the more important...machines and to increased safety norms. Many structures to be monitored, e.g., civil engineering structures subject to wind and earthquakes , aircraft

Multimodal and synthetic aperture approach to full-field 3D shape and displacement measurements

NASA Astrophysics Data System (ADS)

Kujawińska, M.; Sitnik, R.

2017-08-01

Recently most of the measurement tasks in industry, civil engineering and culture heritage applications require archiving, characterization and monitoring of 3D objects and structures and their performance under changing conditions. These requirements can be met if multimodal measurement (MM) strategy is applied. It rely on effective combining structured light method and 3D digital image correlation with laser scanning/ToF, thermal imaging, multispectral imaging and BDRF measurements. In the case of big size and/or complicated objects MM have to be combined with hierarchical or synthetic aperture (SA) measurements. The new solutions in MM and SA strategies are presented and their applicability is shown at interesting cultural heritage and civil engineering applications.

Damage detection of civil infrastructures with piezoelectric oscillator sensors

NASA Astrophysics Data System (ADS)

Roh, Y. R.; Kim, D. Y.; Park, S. H.; Yun, C. B.

2006-03-01

Many researches have been reported on the condition monitoring of civil infrastructures by means of piezoelectric sensors. Most of them made use of the impedance change of the piezoelectric device in relation to the creation of internal damages to the structure. The impedance measurement is a well accepted method in the piezoelectric sensor area, and has been proved by many authors to be useful for civil structure diagnosis. However, the impedance measurement normally requires sophisticated equipment and analysis technology. For more general and wide application of the piezoelectric diagnosis tool, a new methodology is desired to overcome the limitations of the impedance measurement. This paper presents the feasibility of a piezoelectric oscillator sensor to detect the damages in civil infrastructures. The oscillator sensor is composed of an electronic feedback oscillator circuit and a piezoelectric thickness mode vibrator to be attached to the structure of interest. Damage to the structure causes a change in the impedance spectrum of the structure, which results in a corresponding change of the resonant frequency of the structure. The oscillator sensors can instantly detect the frequency change in a very simple manner. Feasibility of the piezoelectric oscillator sensor was verified in this work with a sample aluminum plate where artificial cracks of different depth were imposed in sequence. Validity of the measurement was confirmed through comparison of the experimental data with the results of finite element analyses of the plate with cracks. Performance of the oscillator sensor was also compared with that of its conventional counterpart, i.e. impedance measurement, to manifest the superiority of the oscillator sensor.

Deep Learning and Image Processing for Automated Crack Detection and Defect Measurement in Underground Structures

NASA Astrophysics Data System (ADS)

Panella, F.; Boehm, J.; Loo, Y.; Kaushik, A.; Gonzalez, D.

2018-05-01

This work presents the combination of Deep-Learning (DL) and image processing to produce an automated cracks recognition and defect measurement tool for civil structures. The authors focus on tunnel civil structures and survey and have developed an end to end tool for asset management of underground structures. In order to maintain the serviceability of tunnels, regular inspection is needed to assess their structural status. The traditional method of carrying out the survey is the visual inspection: simple, but slow and relatively expensive and the quality of the output depends on the ability and experience of the engineer as well as on the total workload (stress and tiredness may influence the ability to observe and record information). As a result of these issues, in the last decade there is the desire to automate the monitoring using new methods of inspection. The present paper has the goal of combining DL with traditional image processing to create a tool able to detect, locate and measure the structural defect.

Monitoring system of arch bridge for safety network management

NASA Astrophysics Data System (ADS)

Joo, Bong Chul; Yoo, Young Jun; Lee, Chin Hyung; Park, Ki Tae; Hwang, Yoon Koog

2010-03-01

Korea has constructed the safety management network monitoring test systems for the civil infrastructure since 2006 which includes airport structure, irrigation structure, railroad structure, road structure, and underground structure. Bridges among the road structure include the various superstructure types which are Steel box girder bridge, suspension bridge, PSC-box-girder bridge, and arch bridge. This paper shows the process of constructing the real-time monitoring system for the arch bridge and the measured result by the system. The arch type among various superstructure types has not only the structural efficiency but the visual beauty, because the arch type superstructure makes full use of the feature of curve. The main measuring points of arch bridges composited by curved members make a difference to compare with the system of girder bridges composited by straight members. This paper also shows the method to construct the monitoring system that considers the characteristic of the arch bridge. The system now includes strain gauges and thermometers, and it will include various sensor types such as CCTV, accelerometers and so on additionally. For the long term and accuracy monitoring, the latest optical sensors and equipments are applied to the system.

Health monitoring of the Saint-Jean bridge of Bordeaux, France using fiber Bragg grating extensometers

NASA Astrophysics Data System (ADS)

Magne, Sylvain; Boussoir, Jonathan; Rougeault, Stephane; Marty-Dewynter, Veronique; Ferdinand, Pierre; Bureau, Lionel

2003-07-01

Most civil engineering structures have been built in the 50's and 60's and reach similar level of degradation accelerated by loading conditions and corrosion. In Europe, National Authorities and the European Commission promote Health Monitoring concepts, instrumentation of existing structures and help in the design of new durable structures of higher performance. In this context, the CEA-List has achieved a non-exclusive industrial transfer of its Bragg grating sensing technology for civil engineering applications to Hydrolog (French SME), supported by the European Community and the french ministry of Industry. In order to check the reliability and user-friendliness of this instrumentation, eleven spectrally-multiplexed Bragg grating-based extensometers, four FBG temperature sensors and an acquisition unit have been installed into the Saint-Jean bridge in Bordeaux, France with the help of the Infrastructure Regional Direction (DRE-Aquitaine) and the Bordeaux Authority (Communaute Urbaine de Bordeaux). A standardized loading of the bridge has been performed on October 29, 1001, with the purpose of correlating its mechanical reaction to loading conditions. Moreover, the equipment has been operating for one year to take into account the winter-summer cycle.

Definition study of land/sea civil user navigational location monitoring systems for NAVSTAR GPS: User requirements and systems concepts

NASA Technical Reports Server (NTRS)

Devito, D. M.

1981-01-01

A low-cost GPS civil-user mobile terminal whose purchase cost is substantially an order of magnitude less than estimates for the military counterpart is considered with focus on ground station requirements for position monitoring of civil users requiring this capability and the civil user navigation and location-monitoring requirements. Existing survey literature was examined to ascertain the potential users of a low-cost NAVSTAR receiver and to estimate their number, function, and accuracy requirements. System concepts are defined for low cost user equipments for in-situ navigation and the retransmission of low data rate positioning data via a geostationary satellite to a central computing facility.

The Cloud2SM Project

NASA Astrophysics Data System (ADS)

Crinière, Antoine; Dumoulin, Jean; Mevel, Laurent; Andrade-Barosso, Guillermo; Simonin, Matthieu

2015-04-01

From the past decades the monitoring of civil engineering structure became a major field of research and development process in the domains of modelling and integrated instrumentation. This increasing of interest can be attributed in part to the need of controlling the aging of such structures and on the other hand to the need to optimize maintenance costs. From this standpoint the project Cloud2SM (Cloud architecture design for Structural Monitoring with in-line Sensors and Models tasking), has been launched to develop a robust information system able to assess the long term monitoring of civil engineering structures as well as interfacing various sensors and data. The specificity of such architecture is to be based on the notion of data processing through physical or statistical models. Thus the data processing, whether material or mathematical, can be seen here as a resource of the main architecture. The project can be divided in various items: -The sensors and their measurement process: Those items provide data to the main architecture and can embed storage or computational resources. Dependent of onboard capacity and the amount of data generated it can be distinguished heavy and light sensors. - The storage resources: Based on the cloud concept this resource can store at least two types of data, raw data and processed ones. - The computational resources: This item includes embedded "pseudo real time" resources as the dedicated computer cluster or computational resources. - The models: Used for the conversion of raw data to meaningful data. Those types of resources inform the system of their needs they can be seen as independents blocks of the system. - The user interface: This item can be divided in various HMI to assess maintaining operation on the sensors or pop-up some information to the user. - The demonstrators: The structures themselves. This project follows previous research works initiated in the European project ISTIMES [1]. It includes the infrared thermal monitoring of civil engineering structures [2-3] and/or the vibration monitoring of such structures [4-5]. The chosen architecture is based on the OGC standard in order to ensure the interoperability between the various measurement systems. This concept is extended to the notion of physical models. The last but not the least main objective of this project is to explore the feasibility and the reliability to deploy mathematical models and process a large amount of data using the GPGPU capacity of a dedicated computational cluster, while studying OGC standardization to those technical concepts. References [1] M. Proto et al., « Transport Infrastructure surveillance and Monitoring by Electromagnetic Sensing: the ISTIMES project », Journal Sensors, Sensors 2010, 10(12), 10620-10639; doi:10.3390/s101210620, December 2010. [2] J. Dumoulin, A. Crinière, R. Averty ," Detection and thermal characterization of the inner structure of the "Musmeci" bridge deck by infrared thermography monitoring ",Journal of Geophysics and Engineering, Volume 10, Number 2, 17 pages ,November 2013, IOP Science, doi:10.1088/1742-2132/10/6/064003. [3] J Dumoulin and V Boucher; "Infrared thermography system for transport infrastructures survey with inline local atmospheric parameter measurements and offline model for radiation attenuation evaluations," J. Appl. Remote Sens., 8(1), 084978 (2014). doi:10.1117/1.JRS.8.084978. [4] V. Le Cam, M. Doehler, M. Le Pen, L. Mevel. "Embedded modal analysis algorithms on the smart wireless sensor platform PEGASE", In Proc. 9th International Workshop on Structural Health Monitoring, Stanford, CA, USA, 2013. [5] M. Zghal, L. Mevel, P. Del Moral, "Modal parameter estimation using interacting Kalman filter", Mechanical Systems and Signal Processing, 2014.

Spectrally encoded optical fibre sensor systems and their application in process control, environmental and structural monitoring

NASA Astrophysics Data System (ADS)

Willsch, Reinhardt; Ecke, Wolfgang; Schwotzer, Gunter

2005-09-01

Different types of advanced optical fibre sensor systems using similar spectral interrogation principles and potential low-cost polychromator optoelectronic signal processing instrumentation will be presented, and examples of their industrial application are demonstrated. These are such sensors as multimode fibre based humidity, temperature, and pressure sensors with extrinsic microoptical Fabry-Perot transducers for process control in gas industry, UV absorption evanescent field sensors for organic pollution monitoring in groundwater, and single mode fibre Bragg grating (FBG) multiplexed strain & vibration and temperature sensor networks for structural health monitoring applications in electric power facilities, aerospace, railways, geotechnical and civil engineering. Recent results of current investigations applying FBGs and microstructured fibres for chemical sensing will be discussed.

Laser based structural health monitoring for civil, mechanical, and aerospace systems

NASA Astrophysics Data System (ADS)

Sohn, Hoon

2012-04-01

This paper provides an overview of ongoing laser ultrasonics based structural health monitoring (SHM) activities being performed by the author. Particular focus is given to (1) the development of a fully noncontact laser ultrasonic system that can easily visualize defects with high spatial resolution, (2) laser based wireless power and data transmission schemes for remote guided waves and impedance measurements, (3) minimization of false alarms due to varying operational and environmental conditions, and (4) extension to embedded laser ultrasonic excitation and sensing. SHM examples ranging from bridges to airplanes, as well as nuclear power plants, high-speed rails and wind turbines are also presented.

Health monitoring system for a tall building with Fiber Bragg grating sensors

NASA Astrophysics Data System (ADS)

Li, D. S.; Li, H. N.; Ren, L.; Guo, D. S.; Song, G. B.

2009-03-01

Fiber Bragg grating (FBG) sensors demonstrate great potentials for structural health monitoring of civil structures to ensure their structural integrity, durability and reliability. The advantages of applying fiber optic sensors to a tall building include their immunity of electromagnetic interference and multiplexing ability to transfer optical signals over a long distance. In the work, FBG sensors, including strain and temperature sensors, are applied to the construction monitoring of an 18-floor tall building starting from its construction date. The main purposes of the project are: 1) monitoring the temperature evolution history within the concrete during the pouring process; 2) measuring the variations of the main column strains on the underground floor while upper 18 floors were subsequently added on; and 3) monitoring the relative displacements between two foundation blocks. The FBG sensors have been installed and interrogated continuously for more than five months. Monitoring results of temperature and strains during the period are presented in the paper. Furthermore, the lag behavior between the concrete temperature and its surrounding air temperature is investigated.

Effects of non-structural components and soil-structure interaction on the seismic response of framed structures

NASA Astrophysics Data System (ADS)

Ditommaso, Rocco; Auletta, Gianluca; Iacovino, Chiara; Nigro, Antonella; Carlo Ponzo, Felice

2017-04-01

In this paper, several nonlinear numerical models of reinforced concrete framed structures have been defined in order to evaluate the effects of non-structural elements and soil-structure interaction on the elastic dynamic behaviour of buildings. In the last few years, many and various studies have highlighted the significant effects derived from the interaction between structural and non-structural components on the main dynamic characteristics of a building. Usually, structural and non-structural elements act together, adding both masses and stiffness. The presence of infill panels is generally neglected in the design process of structural elements, although these elements can significantly increase the lateral stiffness of a structure leading to a modification in the dynamic properties. Particularly, at the Damage Limit State (where an elastic behaviour is expected), soil-structure interaction effects and non-structural elements may further affect the elastic natural period of buildings, changing the spectral accelerations compared with those provided by seismic codes in case of static analyses. In this work, a parametric study has been performed in order to evaluate the elastic fundamental period of vibration of buildings as a function of structural morphology (height, plan area, ratio between plan dimensions), infills presence and distribution and soil characteristics. Acknowledgements This study was partially funded by the Italian Department of Civil Protection within the project DPC-RELUIS 2016 - RS4 ''Seismic observatory of structures and health monitoring'' and by the "Centre of Integrated Geomorphology for the Mediterranean Area - CGIAM" within the Framework Agreement with the University of Basilicata "Study, Research and Experimentation in the Field of Analysis and Monitoring of Seismic Vulnerability of Strategic and Relevant Buildings for the purposes of Civil Protection and Development of Innovative Strategies of Seismic Reinforcement".

Selection of suitable NDT methods for building inspection

NASA Astrophysics Data System (ADS)

Pauzi Ismail, Mohamad

2017-11-01

Construction of modern structures requires good quality concrete with adequate strength and durability. Several accidents occurred in the civil constructions and were reported in the media. Such accidents were due to poor workmanship and lack of systematic monitoring during the constructions. In addition, water leaking and cracking in residential houses was commonly reported too. Based on these facts, monitoring the quality of concrete in structures is becoming more and more important subject. This paper describes major Non-destructive Testing (NDT) methods for evaluating structural integrity of concrete building. Some interesting findings during actual NDT inspections on site are presented. The NDT methods used are explained, compared and discussed. The suitable methods are suggested as minimum NDT methods to cover parameters required in the inspection.

Coupling Sensing Hardware with Data Interrogation Software for Structural Health Monitoring

DOE PAGES

Farrar, Charles R.; Allen, David W.; Park, Gyuhae; ...

2006-01-01

The process of implementing a damage detection strategy for aerospace, civil and mechanical engineering infrastructure is referred to as structural health monitoring (SHM). The authors' approach is to address the SHM problem in the context of a statistical pattern recognition paradigm. In this paradigm, the process can be broken down into four parts: (1) Operational Evaluation, (2) Data Acquisition and Cleansing, (3) Feature Extraction and Data Compression, and (4) Statistical Model Development for Feature Discrimination. These processes must be implemented through hardware or software and, in general, some combination of these two approaches will be used. This paper will discussmore » each portion of the SHM process with particular emphasis on the coupling of a general purpose data interrogation software package for structural health monitoring with a modular wireless sensing and processing platform. More specifically, this paper will address the need to take an integrated hardware/software approach to developing SHM solutions.« less

Monitoring early hydration of reinforced concrete structures using structural parameters identified by piezo sensors via electromechanical impedance technique

NASA Astrophysics Data System (ADS)

Talakokula, Visalakshi; Bhalla, Suresh; Gupta, Ashok

2018-01-01

Concrete is the most widely used material in civil engineering construction. Its life begins when the hydration process is activated after mixing the cement granulates with water. In this paper, a non-dimensional hydration parameter, obtained from piezoelectric ceramic (PZT) patches bonded to rebars embedded inside concrete, is employed to monitor the early age hydration of concrete. The non-dimensional hydration parameter is derived from the equivalent stiffness determined from the piezo-impedance transducers using the electro-mechanical impedance (EMI) technique. The focus of the study is to monitor the hydration process of cementitious materials commencing from the early hours and continue till 28 days using single non-dimensional parameter. The experimental results show that the proposed piezo-based non-dimensional hydration parameter is very effective in monitoring the early age hydration, as it has been derived from the refined structural impedance parameters, obtained by eliminating the PZT contribution, and using both the real and imaginary components of the admittance signature.

Civil engineering support for the traffic monitoring program : final report, January 2010.

DOT National Transportation Integrated Search

2010-01-01

This project was aimed at providing various civil engineering support services for the telemetered traffic monitoring sites operated by the Statistics Office of the Florida Department of Transportation. This was a companion project to the one that pr...

Integration of High-Resolution Laser Displacement Sensors and 3D Printing for Structural Health Monitoring

PubMed Central

Chang, Shu-Wei; Kuo, Shih-Yu; Huang, Ting-Hsuan

2017-01-01

This paper presents a novel experimental design for complex structural health monitoring (SHM) studies achieved by integrating 3D printing technologies, high-resolution laser displacement sensors, and multiscale entropy SHM theory. A seven-story structure with a variety of composite bracing systems was constructed using a dual-material 3D printer. A wireless Bluetooth vibration speaker was used to excite the ground floor of the structure, and high-resolution laser displacement sensors (1-μm resolution) were used to monitor the displacement history on different floors. Our results showed that the multiscale entropy SHM method could detect damage on the 3D-printed structures. The results of this study demonstrate that integrating 3D printing technologies and high-resolution laser displacement sensors enables the design of cheap, fast processing, complex, small-scale civil structures for future SHM studies. The novel experimental design proposed in this study provides a suitable platform for investigating the validity and sensitivity of SHM in different composite structures and damage conditions for real life applications in the future. PMID:29271937

Integration of High-Resolution Laser Displacement Sensors and 3D Printing for Structural Health Monitoring.

PubMed

Chang, Shu-Wei; Lin, Tzu-Kang; Kuo, Shih-Yu; Huang, Ting-Hsuan

2017-12-22

This paper presents a novel experimental design for complex structural health monitoring (SHM) studies achieved by integrating 3D printing technologies, high-resolution laser displacement sensors, and multiscale entropy SHM theory. A seven-story structure with a variety of composite bracing systems was constructed using a dual-material 3D printer. A wireless Bluetooth vibration speaker was used to excite the ground floor of the structure, and high-resolution laser displacement sensors (1-μm resolution) were used to monitor the displacement history on different floors. Our results showed that the multiscale entropy SHM method could detect damage on the 3D-printed structures. The results of this study demonstrate that integrating 3D printing technologies and high-resolution laser displacement sensors enables the design of cheap, fast processing, complex, small-scale civil structures for future SHM studies. The novel experimental design proposed in this study provides a suitable platform for investigating the validity and sensitivity of SHM in different composite structures and damage conditions for real life applications in the future.

Fatigue and post-fatigue performance of Fabry-Perot FOS installed on CFRP-strengthened RC-beams

NASA Astrophysics Data System (ADS)

Gheorghiu, Catalin; Labossiere, Pierre; Proulx, Jean

2004-07-01

There is a growing need for built-in monitoring systems for civil engineering infrastructures, due to problems such as increasing traffic loads and rising costs of maintenance and repair. Fibre optic sensors (FOS), capable of reading various parameters are promising candidates for life-long health monitoring of these structures. However, since FOS have only been introduced recently into the field of structural monitoring, their acceptance and widespread implementation will be conditioned by their durability under severe climatic and loading conditions. This paper reports on the performance of strain extrinsic FOS attached to carbon fibre reinforced polymer (CFRP) plates used to strengthen concrete structures. The specimens tested in this project are reinforced concrete (RC) beams with an additional external CFRP reinforcement. The FOS-instrumented beams were first subjected to fatigue loading for various numbers of cycles and load amplitudes. Then, they were tested monotonically to failure under four-point-bending. The test results provide an insight on the fatigue and post-fatigue behaviour of FOS used for monitoring reinforced concrete structures.

Application of smart optical fiber sensors for structural load monitoring

NASA Astrophysics Data System (ADS)

Davies, Heddwyn; Everall, Lorna A.; Gallon, Andrew M.

2001-06-01

This paper describes a smart monitoring system, incorporating optical fiber sensing techniques, capable of providing important structural information to designers and users alike. This technology has wide industrial and commercial application in areas including aerospace, civil, maritime and automotive engineering. In order to demonstrate the capability of the sensing system it has been installed in a 35m free-standing carbon fiber yacht mast, where a complete optical network of strain and temperature sensors were embedded into a composite mast and boom during lay-up. The system was able to monitor the behavior of the composite rig through a range of handling conditions. The resulting strain information can be used by engineers to improve the structural design process. Embedded fiber optic sensors have wide ranging application for structural load monitoring. Due to their small size, optical fiber sensors can be readily embedded into composite materials. Other advantages include their immediate multiplexing capability and immunity to electro-magnetic interference. The capability of this system has been demonstrated within the maritime and industrial environment, but can be adapted for any application.

Real-time kinematic PPP GPS for structure monitoring applied on the Severn Suspension Bridge, UK

NASA Astrophysics Data System (ADS)

Tang, Xu; Roberts, Gethin Wyn; Li, Xingxing; Hancock, Craig Matthew

2017-09-01

GPS is widely used for monitoring large civil engineering structures in real time or near real time. In this paper the use of PPP GPS for monitoring large structures is investigated. The bridge deformation results estimated using double differenced measurements is used as the truth against which the performance of kinematic PPP in a real-time scenario for bridge monitoring is assessed. The towers' datasets with millimetre level movement and suspension cable dataset with centimetre/decimetre level movement were processed by both PPP and DD data processing methods. The consistency of tower PPP time series indicated that the wet tropospheric delay is the major obstacle for small deflection extraction. The results of suspension cable survey points indicate that an ionospheric-free linear measurement is competent for bridge deformation by PPP kinematic model, the frequency domain analysis yields very similar results using either PPP or DD. This gives evidence that PPP can be used as an alternative method to DD for large structure monitoring when DD is difficult or impossible because of large baseline lengths, power outages or natural disasters. The PPP residual tropospheric wet delays can be applied to improve the capacity of small movement extraction.

Special sensors for deformation measurements of different construction materials and structures

NASA Astrophysics Data System (ADS)

Glisic, Branko; Inaudi, Daniele; Kronenberg, Pascal; LLoret, Sandra; Vurpillot, Samuel

1999-05-01

SOFO is a fiber optic sensor system that allows the monitoring of micrometer deformations over measurement bases up to a few meters. It is particularly adapted to measure civil structures built with conventional civil engineering materials (concrete, steel and timber). It has been successfully tested in different types of structures such as bridges, tunnels and piles. The application of the system is however limited in some case when unusual materials are used in the construction and in other cases by the dimensions of standard SOFO sensors. To extend the domain of application of the current system, special sensors have been developed. In this paper we present four special SOFO sensors: long, membrane, thin and stiff sensors. The long sensor has a measurement basis of several tenths of meters and its purpose is the measurement of deformations in massive and large structures (dames, tunnels). The membrane sensor is for use on laminated materials (e.g. membrane roofing) and it is easy to install by simply gluing it to the structure to be monitored. Since standard sensors can not be used for thin mortar layers because of their cross- section, a thin sensor has been developed, too. Finally, the aim of the stiff sensor is to determine the hardening (solidification) time of concrete. This time is determined by comparing the deformations of a stiff and a standard sensor, closely placed in the concrete at the very early age. The design of these sensors is presented along with significant application examples.

Decentralized system identification using stochastic subspace identification on wireless smart sensor networks

NASA Astrophysics Data System (ADS)

Sim, Sung-Han; Spencer, Billie F., Jr.; Park, Jongwoong; Jung, Hyungjo

2012-04-01

Wireless Smart Sensor Networks (WSSNs) facilitates a new paradigm to structural identification and monitoring for civil infrastructure. Conventional monitoring systems based on wired sensors and centralized data acquisition and processing have been considered to be challenging and costly due to cabling and expensive equipment and maintenance costs. WSSNs have emerged as a technology that can overcome such difficulties, making deployment of a dense array of sensors on large civil structures both feasible and economical. However, as opposed to wired sensor networks in which centralized data acquisition and processing is common practice, WSSNs require decentralized computing algorithms to reduce data transmission due to the limitation associated with wireless communication. Thus, several system identification methods have been implemented to process sensor data and extract essential information, including Natural Excitation Technique with Eigensystem Realization Algorithm, Frequency Domain Decomposition (FDD), and Random Decrement Technique (RDT); however, Stochastic Subspace Identification (SSI) has not been fully utilized in WSSNs, while SSI has the strong potential to enhance the system identification. This study presents a decentralized system identification using SSI in WSSNs. The approach is implemented on MEMSIC's Imote2 sensor platform and experimentally verified using a 5-story shear building model.

Optical Fiber Sensors for Advanced Civil Structures

NASA Astrophysics Data System (ADS)

de Vries, Marten Johannes Cornelius

1995-01-01

The objective of this dissertation is to develop, analyze, and implement optical fiber-based sensors for the nondestructive quantitative evaluation of advanced civil structures. Based on a comparative evaluation of optical fiber sensors that may be used to obtain quantitative information related to physical perturbations in the civil structure, the extrinsic Fabry-Perot interferometric (EFPI) optical fiber sensor is selected as the most attractive sensor. The operation of the EFPI sensor is explained using the Kirchhoff diffraction approach. As is shown in this dissertation, this approach better predicts the signal-to-noise ratio as a function of gap length than methods employed previously. The performance of the optical fiber sensor is demonstrated in three different implementations. In the first implementation, performed with researchers in the Civil Engineering Department at the University of Southern California in Los Angeles, optical fiber sensors were used to obtain quantitative strain information from reinforced concrete interior and exterior column-to-beam connections. The second implementation, performed in cooperation with researchers at the United States Bureau of Mines in Spokane, Washington, used optical fiber sensors to monitor the performance of roof bolts used in mines. The last implementation, performed in cooperation with researchers at the Turner-Fairbanks Federal Highway Administration Research Center in McLean, Virginia, used optical fiber sensors, attached to composite prestressing strands used for reinforcing concrete, to obtain absolute strain information. Multiplexing techniques including time, frequency and wavelength division multiplexing are briefly discussed, whereas the principles of operation of spread spectrum and optical time domain reflectometery (OTDR) are discussed in greater detail. Results demonstrating that spread spectrum and OTDR techniques can be used to multiplex optical fiber sensors are presented. Finally, practical considerations that have to be taken into account when implementing optical fiber sensors into a civil structure environment are discussed, and possible solutions to some of these problems are proposed.

Surveying and monitoring for vulnerability assessment of an ancient building.

PubMed

Fregonese, Luigi; Barbieri, Gaia; Biolzi, Luigi; Bocciarelli, Massimiliano; Frigeri, Aronne; Taffurelli, Laura

2013-07-31

This paper examines how surveying and monitoring improve our knowledge about ancient buildings, allow the interpretation of their structural response and help in the search for the best solutions for their conservation. The case study of Palazzo del Capitano in Mantua (Italy) is analyzed. In particular, the attention is focused on the use of a Terrestrial Laser Scanner (TLS) for surveying and monitoring too, considering that the building structural control has been performed in combination with other traditional topographic techniques such as geometric leveling and topographic networks for 3D control based on measurements through total stations. The study of TLS monitoring has been tested only in the last decade and it is an innovative method for the detection of displacements of particular surfaces. Till now the research has focused only on the use of TLS monitoring to control large structures and in particular landscape situations; thus its use for a civil construction and historical buildings is a new field of investigation. Despite the fact technological development and new methodologies seem offer new future potential for the analysis of ancient buildings, currently there are still important limits for the application of the investigated surveying and monitoring techniques.

Surveying and Monitoring for Vulnerability Assessment of an Ancient Building

PubMed Central

Fregonese, Luigi; Barbieri, Gaia; Biolzi, Luigi; Bocciarelli, Massimiliano; Frigeri, Aronne; Taffurelli, Laura

2013-01-01

This paper examines how surveying and monitoring improve our knowledge about ancient buildings, allow the interpretation of their structural response and help in the search for the best solutions for their conservation. The case study of Palazzo del Capitano in Mantua (Italy) is analyzed. In particular, the attention is focused on the use of a Terrestrial Laser Scanner (TLS) for surveying and monitoring too, considering that the building structural control has been performed in combination with other traditional topographic techniques such as geometric leveling and topographic networks for 3D control based on measurements through total stations. The study of TLS monitoring has been tested only in the last decade and it is an innovative method for the detection of displacements of particular surfaces. Till now the research has focused only on the use of TLS monitoring to control large structures and in particular landscape situations; thus its use for a civil construction and historical buildings is a new field of investigation. Despite the fact technological development and new methodologies seem offer new future potential for the analysis of ancient buildings, currently there are still important limits for the application of the investigated surveying and monitoring techniques. PMID:23912425

Early-age monitoring of cement structures using FBG sensors

NASA Astrophysics Data System (ADS)

Wang, Chuan; Zhou, Zhi; Zhang, Zhichun; Ou, Jinping

2006-03-01

With more and more broad applications of the cement-based structures such as neat cement paste, cement mortar and concrete in civil engineering, people hope to find out what their performances should like. The in-service performances of cement-based structures are highly affected by their hardening process during the early-age. But it is still a big problem for traditional sensors to be used to monitor the early curing of cement-based structures due to such disadvantages as difficulties to install sensors inside the concrete, limited measuring points, poor durability and interference of electromagnetic wave and so on. In this paper, according to the sensing properties of the Fiber Bragg Grating sensors and self-characters of the cement-based structures, we have successfully finished measuring and monitoring the early-age inner-strain and temperature changes of the neat cement paste, concrete with and without restrictions, mass concrete structures and negative concrete, respectively. Three types of FBG-based sensors have been developed to monitor the cement-based structures. Besides, the installation techniques and the embedding requirements of FBG sensors in cement-based structures are also discussed. Moreover, such kind of technique has been used in practical structure, 3rd Nanjing Yangtze Bridge, and the results show that FBG sensors are well proper for measuring and monitoring the temperature and strain changes including self-shrinkage, dry shrinkage, plastic shrinkage, temperature expansion, frost heaving and so on inside different cement-based structures. This technique provides us a new useful measuring method on early curing monitoring of cement-based structures and greater understanding of details of their hardening process.

Impedance based sensor technology to monitor stiffness of biological structures

NASA Astrophysics Data System (ADS)

Annamdas, Venu Gopal Madhav; Annamdas, Kiran Kishore Kumar

2010-04-01

In countries like USA or Japan it is not so uncommon to have wooden structures in their homes. However, metals and its alloys are the most widely used engineering materials in construction of any military or civil structure. Revisiting natural disasters like the recent Haiti earthquake (12 Jan 2010) or Katrina (cyclones) reminds the necessity to have better housing infrastructure with robust monitoring systems. Traditionally wood is accepted as excellent rehabilitation material, after any disaster. The recycling materials extracted from in-organic, biodegradable wastes, also can be used for rehabilitation. The key issue which dampens the life of these rehabilitated structure including green materials (like wood) is unnecessary deposits (nails, screws, bolts etc)/damages due to insect attack. Thus, a few health monitoring techniques have emerged in the recent past. Electromechanical Impedance technique is one such technique, which is simple but robust to detect variations in the integrity of structures. In this paper, impedance based piezoceramic sensor was bonded on wooden sample, which was used to study changes due to metallic (steel nails) deposits at various locations. A study of weight deposits on aluminum plate was used for comparisons.

An autonomous unmanned aerial vehicle sensing system for structural health monitoring of bridges

NASA Astrophysics Data System (ADS)

Reagan, Daniel; Sabato, Alessandro; Niezrecki, Christopher; Yu, Tzuyang; Wilson, Richard

2016-04-01

As civil infrastructure (i.e. bridges, railways, and tunnels) continues to age; the frequency and need to perform inspection more quickly on a broader scale increases. Traditional inspection and monitoring techniques (e.g., visual inspection, mechanical sounding, rebound hammer, cover meter, electrical potential measurements, ultrasound, and ground penetrating radar) may produce inconsistent results, require lane closure, are labor intensive and time-consuming. Therefore, new structural health monitoring systems must be developed that are automated, highly accurate, minimally invasive, and cost effective. Three-dimensional (3D) digital image correlation (DIC) systems have the merits of extracting full-field strain, deformation, and geometry profiles. These profiles can then be stitched together to generate a complete integrity map of the area of interest. Concurrently, unmanned aerial vehicles (UAVs) have emerged as valuable resources for positioning sensing equipment where it is either difficult to measure or poses a risk to human safety. UAVs have the capability to expedite the optical-based measurement process, offer increased accessibility, and reduce interference with local traffic. Within this work, an autonomous unmanned aerial vehicle in conjunction with 3D DIC was developed for monitoring bridges. The capabilities of the proposed system are demonstrated in both laboratory measurements and data collected from bridges currently in service. Potential measurement influences from platform instability, rotor vibration and positioning inaccuracy are also studied in a controlled environment. The results of these experiments show that the combination of autonomous flight with 3D DIC and other non-contact measurement systems provides a valuable and effective civil inspection platform.

Criminal law repercussions on the Civil Protection System

NASA Astrophysics Data System (ADS)

Altamura, M.; Musso, L.

2009-09-01

The legal systems of our Countries provide the citizenship with a high level of protection. Personal safety and the protection of property are guaranteed by the State through organized structures among which we can include the Civil Protection. The progress of science and technology has greatly improved monitoring tools, currently used by the Civil Protection, which allow, to a certain extent, to predict and prevent risk and natural hazards. The assertion of an individual right, which in some cases has reached a constitutional rank, to benefit from Civil Protection services and the widespread perception throughout the citizenship of the competence of the system to prevent disasters, often causes people to take legal action against Civil Protection authorities should they fail in their duties to protect. However, the attempt of having both recognized an economic compensation for the suffered loss and the punishment of those whom misled, frequently undergoes criminal law. This process could have results that may jeopardize the effectiveness of Civil Protection service without meeting citizens’ demands. A dual effort is thus necessary in order to solve such a problem. On the one hand, an interdisciplinary knowledge needs to pervade criminal law in an attempt to relieve its self-referentiality and pretended supremacy. On the other hand an alternative, and more agile, system -such as civil or administrative law- has to be identified in order to respond to the legitimate requests for protection in the case of a faulty behaviour of the authorities.

A framework for the damage evaluation of acoustic emission signals through Hilbert-Huang transform

NASA Astrophysics Data System (ADS)

Siracusano, Giulio; Lamonaca, Francesco; Tomasello, Riccardo; Garescì, Francesca; Corte, Aurelio La; Carnì, Domenico Luca; Carpentieri, Mario; Grimaldi, Domenico; Finocchio, Giovanni

2016-06-01

The acoustic emission (AE) is a powerful and potential nondestructive testing method for structural monitoring in civil engineering. Here, we show how systematic investigation of crack phenomena based on AE data can be significantly improved by the use of advanced signal processing techniques. Such data are a fundamental source of information that can be used as the basis for evaluating the status of the material, thereby paving the way for a new frontier of innovation made by data-enabled analytics. In this article, we propose a framework based on the Hilbert-Huang Transform for the evaluation of material damages that (i) facilitates the systematic employment of both established and promising analysis criteria, and (ii) provides unsupervised tools to achieve an accurate classification of the fracture type, the discrimination between longitudinal (P-) and traversal (S-) waves related to an AE event. The experimental validation shows promising results for a reliable assessment of the health status through the monitoring of civil infrastructures.

Strain Sharing Assessment in Woven Fiber Reinforced Concrete Beams Using Fiber Bragg Grating Sensors

PubMed Central

Montanini, Roberto; Recupero, Antonino; De Domenico, Fabrizio; Freni, Fabrizio

2016-01-01

Embedded fiber Bragg grating sensors have been extensively used worldwide for health monitoring of smart structures. In civil engineering, they provide a powerful method for monitoring the performance of composite reinforcements used for concrete structure rehabilitation and retrofitting. This paper discusses the problem of investigating the strain transfer mechanism in composite strengthened concrete beams subjected to three-point bending tests. Fiber Bragg grating sensors were embedded both in the concrete tensioned surface and in the woven fiber reinforcement. It has been shown that, if interface decoupling occurs, strain in the concrete can be up to 3.8 times higher than that developed in the reinforcement. A zero friction slipping model was developed which fitted very well the experimental data. PMID:27669251

Strain Sharing Assessment in Woven Fiber Reinforced Concrete Beams Using Fiber Bragg Grating Sensors.

PubMed

Montanini, Roberto; Recupero, Antonino; De Domenico, Fabrizio; Freni, Fabrizio

2016-09-22

Embedded fiber Bragg grating sensors have been extensively used worldwide for health monitoring of smart structures. In civil engineering, they provide a powerful method for monitoring the performance of composite reinforcements used for concrete structure rehabilitation and retrofitting. This paper discusses the problem of investigating the strain transfer mechanism in composite strengthened concrete beams subjected to three-point bending tests. Fiber Bragg grating sensors were embedded both in the concrete tensioned surface and in the woven fiber reinforcement. It has been shown that, if interface decoupling occurs, strain in the concrete can be up to 3.8 times higher than that developed in the reinforcement. A zero friction slipping model was developed which fitted very well the experimental data.

Development of a Wireless Unified-Maintenance System for the Structural Health Monitoring of Civil Structures

PubMed Central

Son, Byungjik; Jeon, Seunggon

2018-01-01

A disaster preventive structural health monitoring (SHM) system needs to be equipped with the following abilities: First, it should be able to simultaneously measure diverse types of data (e.g., displacement, velocity, acceleration, strain, load, temperature, humidity, etc.) for accurate diagnosis. Second, it also requires standalone power supply to guarantee its immediate response in crisis (e.g., sudden interruption of normal AC power in disaster situations). Furthermore, it should be capable of prompt processing and realtime wireless communication of a huge amount of data. Therefore, this study is aimed at developing a wireless unified-maintenance system (WUMS) that would satisfy all the requirements for a disaster preventive SHM system of civil structures. The WUMS is designed to measure diverse types of structural responses in realtime based on wireless communication, allowing users to selectively use WiFi RF band and finally working in standalone mode by means of the field-programmable gate array (FPGA) technology. To verify its performance, the following tests were performed: (i) A test to see how far communication is possible in open field, (ii) a test on a shaker to see how accurate responses are, (iii) a modal test on a bridge to see how exactly characteristic real-time dynamic responses are of structures. The test results proved that the WUMS was able to secure stable communication far up to nearly 800 m away by acquiring wireless responses in realtime accurately, when compared to the displacement and acceleration responses which were acquired through wired communication. The analysis of dynamic characteristics also showed that the wireless acceleration responses in real-time represented satisfactorily the dynamic properties of structures. Therefore, the WUMS is proved valid as a SHM, and its outstanding performance is also proven. PMID:29747403

Development of a Wireless Unified-Maintenance System for the Structural Health Monitoring of Civil Structures.

PubMed

Heo, Gwanghee; Son, Byungjik; Kim, Chunggil; Jeon, Seunggon; Jeon, Joonryong

2018-05-09

A disaster preventive structural health monitoring (SHM) system needs to be equipped with the following abilities: First, it should be able to simultaneously measure diverse types of data (e.g., displacement, velocity, acceleration, strain, load, temperature, humidity, etc.) for accurate diagnosis. Second, it also requires standalone power supply to guarantee its immediate response in crisis (e.g., sudden interruption of normal AC power in disaster situations). Furthermore, it should be capable of prompt processing and realtime wireless communication of a huge amount of data. Therefore, this study is aimed at developing a wireless unified-maintenance system (WUMS) that would satisfy all the requirements for a disaster preventive SHM system of civil structures. The WUMS is designed to measure diverse types of structural responses in realtime based on wireless communication, allowing users to selectively use WiFi RF band and finally working in standalone mode by means of the field-programmable gate array (FPGA) technology. To verify its performance, the following tests were performed: (i) A test to see how far communication is possible in open field, (ii) a test on a shaker to see how accurate responses are, (iii) a modal test on a bridge to see how exactly characteristic real-time dynamic responses are of structures. The test results proved that the WUMS was able to secure stable communication far up to nearly 800 m away by acquiring wireless responses in realtime accurately, when compared to the displacement and acceleration responses which were acquired through wired communication. The analysis of dynamic characteristics also showed that the wireless acceleration responses in real-time represented satisfactorily the dynamic properties of structures. Therefore, the WUMS is proved valid as a SHM, and its outstanding performance is also proven.

Finite Element Modelling and Analysis of Damage Detection Methodology in Piezo Electric Sensor and Actuator Integrated Sandwich Cantilever Beam

NASA Astrophysics Data System (ADS)

Pradeep, K. R.; Thomas, A. M.; Basker, V. T.

2018-03-01

Structural health monitoring (SHM) is an essential component of futuristic civil, mechanical and aerospace structures. It detects the damages in system or give warning about the degradation of structure by evaluating performance parameters. This is achieved by the integration of sensors and actuators into the structure. Study of damage detection process in piezoelectric sensor and actuator integrated sandwich cantilever beam is carried out in this paper. Possible skin-core debond at the root of the cantilever beam is simulated and compared with undamaged case. The beam is actuated using piezoelectric actuators and performance differences are evaluated using Polyvinylidene fluoride (PVDF) sensors. The methodology utilized is the voltage/strain response of the damaged versus undamaged beam against transient actuation. Finite element model of piezo-beam is simulated in ANSYSTM using 8 noded coupled field element, with nodal degrees of freedoms are translations in the x, y directions and voltage. An aluminium sandwich beam with a length of 800mm, thickness of core 22.86mm and thickness of skin 0.3mm is considered. Skin-core debond is simulated in the model as unmerged nodes. Reduction in the fundamental frequency of the damaged beam is found to be negligible. But the voltage response of the PVDF sensor under transient excitation shows significantly visible change indicating the debond. Piezo electric based damage detection system is an effective tool for the damage detection of aerospace and civil structural system having inaccessible/critical locations and enables online monitoring possibilities as the power requirement is minimal.

Image Analysis Technique for Material Behavior Evaluation in Civil Structures

PubMed Central

Moretti, Michele; Rossi, Gianluca

2017-01-01

The article presents a hybrid monitoring technique for the measurement of the deformation field. The goal is to obtain information about crack propagation in existing structures, for the purpose of monitoring their state of health. The measurement technique is based on the capture and analysis of a digital image set. Special markers were used on the surface of the structures that can be removed without damaging existing structures as the historical masonry. The digital image analysis was done using software specifically designed in Matlab to follow the tracking of the markers and determine the evolution of the deformation state. The method can be used in any type of structure but is particularly suitable when it is necessary not to damage the surface of structures. A series of experiments carried out on masonry walls of the Oliverian Museum (Pesaro, Italy) and Palazzo Silvi (Perugia, Italy) have allowed the validation of the procedure elaborated by comparing the results with those derived from traditional measuring techniques. PMID:28773129

Image Analysis Technique for Material Behavior Evaluation in Civil Structures.

PubMed

Speranzini, Emanuela; Marsili, Roberto; Moretti, Michele; Rossi, Gianluca

2017-07-08

The article presents a hybrid monitoring technique for the measurement of the deformation field. The goal is to obtain information about crack propagation in existing structures, for the purpose of monitoring their state of health. The measurement technique is based on the capture and analysis of a digital image set. Special markers were used on the surface of the structures that can be removed without damaging existing structures as the historical masonry. The digital image analysis was done using software specifically designed in Matlab to follow the tracking of the markers and determine the evolution of the deformation state. The method can be used in any type of structure but is particularly suitable when it is necessary not to damage the surface of structures. A series of experiments carried out on masonry walls of the Oliverian Museum (Pesaro, Italy) and Palazzo Silvi (Perugia, Italy) have allowed the validation of the procedure elaborated by comparing the results with those derived from traditional measuring techniques.

Effect of External Vibration on PZT Impedance Signature.

PubMed

Yang, Yaowen; Miao, Aiwei

2008-11-01

Piezoelectric ceramic Lead Zirconate Titanate (PZT) transducers, working on the principle of electromechanical impedance (EMI), are increasingly applied for structural health monitoring (SHM) in aerospace, civil and mechanical engineering. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in the electromechanical admittance (inverse of EMI) signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the monitored structure is only excited by the PZT transducers for the interrogating of EMI signature, while the vibration of the structure caused by the external excitations other than the PZT actuation is not considered. However, many structures work under vibrations in practice. To monitor such structures, issues related to the effects of vibration on the EMI signature need to be addressed because these effects may lead to misinterpretation of the structural health. This paper develops an EMI model for beam structures, which takes into account the effect of beam vibration caused by the external excitations. An experimental study is carried out to verify the theoretical model. A lab size specimen with different external excitations is tested and the effect of vibration on EMI signature is discussed.

GNSS Monitoring of Deformation within heavy civil infrastructure

NASA Astrophysics Data System (ADS)

Montillet, Jean-Philippe; Melbourne, Timothy; Szeliga, Walter; Schrock, Gavin

2015-04-01

The steady increase in precision simultaneous with the decreasing of continuous GPS monitoring has enabled the deployment of receivers for a host of new activities. Here we discuss the precision obtained from several multi-station installations operated over a five-year period on several heavy civil-engineered structures, including two earthen-fill dams and subsiding highway overpass damaged by seismic shaking. In the past 5 years, the Cascadia Hazards Institute (Pacific Northwest Geodetic Array) at Central Washington University together with the Washington department of public utilities (Land Survey) have been monitoring several structures around Seattle area including two dams (Howard Hansen and Tolt). One aim of this study is to test the use of continuous GNSS in order to detect any deformations due to rapid pool level rises or to monitor the safety of a structure when an Earthquake strikes it. In this study, data is processed using Real Time Kinematic GPS with short baseline (d < 500 m) and GPS daily position (PPP). However, multipath is the most limiting factor on accuracy for very precise positioning applications with GPS. It is very often present indoors and outdoors, especially in narrow valleys with a limited view of the sky. As a result, multipath can amount to an error of a few centimetres. Unfortunately, the accuracy requirements of precision deformation monitoring are generally at the sub centimetre level, which is presently a big challenge on an epoch-by-epoch basis with regular, carrier phase techniques. Thus, it needs to be properly mitigated. In this study, several stations are set up on the dams (4 stations on the Tolt reservoir and 10 stations on the Howard Hansen dam), and spatial filtering can then be used to mitigate multipath. In addition, several signal processing techniques are also investigated (i.e. Empirical mode decomposition, sidereal filtering, adaptive filtering). RTK GPS should allow to monitor rapid deformations, whereas GPS daily position is used to detect long-term deformations such as the pool level rises due to the melting of ice cap on surrounding mountains. Note that RTK measurements are processed with the MIT software TRACK and the GPS daily positions estimated with GAMIT-GLOBK.

Piezo impedance sensors to monitor degradation of biological structure

NASA Astrophysics Data System (ADS)

Annamdas, Kiran Kishore Kumar; Annamdas, Venu Gopal Madhav

2010-04-01

In some countries it is common to have wooden structures in their homes, especially Japan. However, metals and its alloys are the most widely used engineering materials in construction of any military or civil structure. Re-visiting natural disasters like the recent Haiti earthquake (12 Jan 2010) or Katrina (cyclones) reminds the necessity to have better housing infrastructure with robust monitoring systems. Traditionally wood (green material) was accepted as excellent rehabilitation material, after any disaster. In recent times, the recycling materials extracted from inorganic, biodegradable wastes are converted into blocks or sheets, and are also used to assist public in rehabilitation camps. The key issue which decreases the life of these rehabilitated structure including green materials (like wood) is unnecessary degradation or deterioration over time due to insect or acid attack or rain/ice fall. The recycling material also needs monitoring to protect them against acid or rain/ice attacks. Thus, a few health monitoring techniques have emerged in the recent past. Electromechanical Impedance technique is one such technique, which is simple but robust to detect variations in the integrity of structures. In this paper, impedance based piezoceramic sensor was bonded on wooden sample, which was subjected to degradation in presence of acids. Variations in mass of plank are studied.

Understanding the Influence of Independent Civil Society Monitoring and Evaluation at the District Level: A Case Study of Ghana

ERIC Educational Resources Information Center

Gildemyn, Marie

2014-01-01

In developing countries, an increasing number of civil society organizations (CSOs) engage in independent monitoring and evaluation (M&E) of government programs and policies. Most CSOs rely on a range of M&E tools in combination with advocacy strategies to hold government accountable and improve the implementation of programs and policies.…

Principles in wireless building health monitoring systems.

NASA Astrophysics Data System (ADS)

Pentaris, F. P.; Makris, J. P.; Stonham, J.; Vallianatos, F.

2012-04-01

Monitoring the structural state of a building is essential for the safety of the people who work, live, visit or just use it as well as for the civil protection of urban areas. Many factors can affect the state of the health of a structure, namely man made, like mistakes in the construction, traffic, heavy loads on the structures, explosions, environmental impacts like wind loads, humidity, chemical reactions, temperature changes and saltiness, and natural hazards like earthquakes and landslides. Monitoring the health of a structure provides the ability to anticipate structural failures and secure the safe use of buildings especially those of public services. This work reviews the state of the art and the challenges of a wireless Structural Health Monitoring (WiSHM). Literature review reveals that although there is significant evolution in wireless structural health monitoring, in many cases, monitoring by itself is not enough to predict when a structure becomes inappropriate and/or unsafe for use, and the damage or low durability of a structure cannot be revealed (Chintalapudi, et al., 2006; Ramos, Aguilar, & Lourenço, 2011). Several features and specifications of WiSHM like wireless sensor networking, reliability and autonomy of sensors, algorithms of data transmission and analysis should still be evolved and improved in order to increase the predictive effectiveness of the SHM (Jinping Ou & Hui Li, 2010; Lu & Loh, 2010) . Acknowledgments This work was supported in part by the ARCHEMEDES III Program of the Ministry of Education of Greece and the European Union in the framework of the project entitled «Interdisciplinary Multi-Scale Research of Earthquake Physics and Seismotectonics at the front of the Hellenic Arc (IMPACT-ARC) ».

76 FR 38294 - Oil and Gas and Sulphur Operations in the Outer Continental Shelf-Civil Penalties

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-30

... 2009, BOEMRE performed computations to determine if it should increase the current maximum civil penalty amount of $35,000 per violation per day. After running the computations, BOEMRE determined that.... BOEMRE has been monitoring the CPI, and the computations now justify raising the maximum civil penalty...

78 FR 50110 - Notice of Lodging Proposed Consent Decree

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... Enterprises, Inc., Civil Action No. 5:13-cv-916 (GLS/DEP) was lodged with the United States District Court for... impose civil penalties against the Defendants for violating the Clean Water Act by discharging pollutants... by requiring the Defendants to restore and monitor the impacted areas and to pay a civil penalty. The...

In situ damage monitoring in vibration mechanics: diagnostics and predictive maintenance

NASA Astrophysics Data System (ADS)

Basseville, M.; Benveniste, A.; Gach-Devauchelle, B.; Goursat, M.; Bonnecase, D.; Dorey, P.; Prevosto, M.; Olagnon, M.

1993-09-01

A system identification approach is presented for damage monitoring in vibration mechanics. Identification, detection, and diagnostics are performed using accelerometer measurements from the system at work so that the excitation is not controlled, usually not observed and may involve turbulent phenomena. Targeted applications include power engineering (rotating machines, core and pipes of nuclear power plants), civil engineering (large buildings subject to hurricanes or earthquakes, bridges, dams, offshore structures), aeronautics (wings and other structures subject to strength), automobile, rail transportation etc. The method is illustrated by a laboratory example, and the results of 3 years industrial usage. This paper is a progress report on a 10 year project involving three people almost permanently. We describe here the whole approach but omit the technical details which are available in previous papers.

Evaluation of crack status in a meter-size concrete structure using the ultrasonic nonlinear coda wave interferometry.

PubMed

Legland, Jean-Baptiste; Zhang, Yuxiang; Abraham, Odile; Durand, Olivier; Tournat, Vincent

2017-10-01

The field of civil engineering is in need of new methods of non-destructive testing, especially in order to prevent and monitor the serious deterioration of concrete structures. In this work, experimental results are reported on fault detection and characterization in a meter-scale concrete structure using an ultrasonic nonlinear coda wave interferometry (NCWI) method. This method entails the nonlinear mixing of strong pump waves with multiple scattered probe (coda) waves, along with analysis of the net effect using coda wave interferometry. A controlled damage protocol is implemented on a post-tensioned, meter-scale concrete structure in order to generate cracking within a specific area being monitored by NCWI. The nonlinear acoustic response due to the high amplitude of acoustic modulation yields information on the elastic nonlinearities of concrete, as evaluated by two specific nonlinear observables. The increase in nonlinearity level corresponds to the creation of a crack with a network of microcracks localized at its base. In addition, once the crack closes as a result of post-tensioning, the residual nonlinearities confirm the presence of the closed crack. Last, the benefits and applicability of this NCWI method to the characterization and monitoring of large structures are discussed.

Using cross correlations of turbulent flow-induced ambient vibrations to estimate the structural impulse response. Application to structural health monitoring.

PubMed

Sabra, Karim G; Winkel, Eric S; Bourgoyne, Dwayne A; Elbing, Brian R; Ceccio, Steve L; Perlin, Marc; Dowling, David R

2007-04-01

It has been demonstrated theoretically and experimentally that an estimate of the impulse response (or Green's function) between two receivers can be obtained from the cross correlation of diffuse wave fields at these two receivers in various environments and frequency ranges: ultrasonics, civil engineering, underwater acoustics, and seismology. This result provides a means for structural monitoring using ambient structure-borne noise only, without the use of active sources. This paper presents experimental results obtained from flow-induced random vibration data recorded by pairs of accelerometers mounted within a flat plate or hydrofoil in the test section of the U.S. Navy's William B. Morgan Large Cavitation Channel. The experiments were conducted at high Reynolds number (Re > 50 million) with the primary excitation source being turbulent boundary layer pressure fluctuations on the upper and lower surfaces of the plate or foil. Identical deterministic time signatures emerge from the noise cross-correlation function computed via robust and simple processing of noise measured on different days by a pair of passive sensors. These time signatures are used to determine and/or monitor the structural response of the test models from a few hundred to a few thousand Hertz.

Application of a Subspace-Based Fault Detection Method to Industrial Structures

NASA Astrophysics Data System (ADS)

Mevel, L.; Hermans, L.; van der Auweraer, H.

1999-11-01

Early detection and localization of damage allow increased expectations of reliability, safety and reduction of the maintenance cost. This paper deals with the industrial validation of a technique to monitor the health of a structure in operating conditions (e.g. rotating machinery, civil constructions subject to ambient excitations, etc.) and to detect slight deviations in a modal model derived from in-operation measured data. In this paper, a statistical local approach based on covariance-driven stochastic subspace identification is proposed. The capabilities and limitations of the method with respect to health monitoring and damage detection are discussed and it is explained how the method can be practically used in industrial environments. After the successful validation of the proposed method on a few laboratory structures, its application to a sports car is discussed. The example illustrates that the method allows the early detection of a vibration-induced fatigue problem of a sports car.

Multi-Sensing system for outdoor thermal monitoring: Application to large scale civil engineering components

NASA Astrophysics Data System (ADS)

Crinière, Antoine; Dumoulin, Jean; Manceau, Jean-Luc; Perez, Laetitia; Bourquin, Frederic

2014-05-01

Aging of transport infrastructures combined with traffic and climatic solicitations contribute to the reduction of their performances. To address and quantify the resilience of civil engineering structure, investigations on robust, fast and efficient methods are required. Among research works carried out at IFSTTAR, methods for long term monitoring face an increasing demand. Such works take benefits of this last decade technological progresses in ICT domain. The present study follows the ISTIMES European project [1], which aimed at demonstrate the ability of different electromagnetic sensing techniques, processing methods and ICT architecture, to be used for long term monitoring of critical transport infrastructures. Thanks to this project a multi-sensing techniques system, able to date and synchronize measurements carried out by infrared thermography coupled with various measurements data (i.e. weather parameters), have been designed, developed and implemented on real site [2]. Among experiments carried out on real transport infrastructure, it has been shown, for the "Musmesci" bridge deck (Italy), that by using infrared thermal image sequence with weather measurements during sevral days it was possible to develop analysis methods able to produce qualitative and quantitative data [3]. In the present study, added functionalities were designed and added to the "IrLAW" system in order to reach full autonomy in term of power supply, very long term measurement capability (at least 1 year) and automated data base feeding. The surveyed civil engineering structures consist in two concrete beams of 16 m long and 21 T weight each. One of the two beams was damage by high energy mechanical impact at the IFSTTAR falling rocks test station facilities located in the French Alpes [4]. The system is composed of one IR uncooled microbolometric camera (FLIR SC325) with a 320X240 Focal Plane Array detector in band III, a weather station VAISALA WXT520, a GPS, a failover power supply and a backup system. All the components of the system are connected to the IrLaW software through an IP network. The monitoring system is fully autonomous since August 2013 and provides data at 0. Hz sampling frequency. First results obtained by data post-processing is addressed. Finally, discussion on experimental feedback and main outcomes of several month of measurement in outdoor conditions will be presented. REFERENCES [1]Proto M. et al., , 2010. Transport infrastructure surveillance and monitoring by electromagnetic sensing: the ISTIMES project. Sensors, 10,10620-10639, doi: 10.3390/s101210620. [2]J. Dumoulin, R. Averty ".Development of an infrared system coupled with a weather station for real time atmospheric corrections using GPU computing: Application to bridge monitoring", in Proc of 11th International Conference on Quantitative InfraRed Thermography, Naples Italy, 2012. [3]J. Dumoulin, A. Crinière, R. Averty ," Detection and thermal characterization of the inner structure of the "Musmeci" bridge deck by infrared thermography monitoring ",Journal of Geophysics and Engineering, Volume 10, Number 2, November 2013, IOP Science, doi:10.1088/1742-2132/10/6/064003. [4]I. Catapano, R. Di Napoli, F. Soldovieri1, M. Bavusi, A. Loperte and J. Dumoulin, "Structural monitoring via microwave tomography-enhanced GPR: the Montagnole test site", Journal of Geophysics and Engineering, Volume 9, Number 4, August 2012, pp 100-107, IOP Science, doi:10.1088/1742-2132/9/4/S100.

Guided Lamb wave based 2-D spiral phased array for structural health monitoring of thin panel structures

NASA Astrophysics Data System (ADS)

Yoo, Byungseok

2011-12-01

In almost all industries of mechanical, aerospace, and civil engineering fields, structural health monitoring (SHM) technology is essentially required for providing the reliable information of structural integrity of safety-critical structures, which can help reduce the risk of unexpected and sometimes catastrophic failures, and also offer cost-effective inspection and maintenance of the structures. State of the art SHM research on structural damage diagnosis is focused on developing global and real-time technologies to identify the existence, location, extent, and type of damage. In order to detect and monitor the structural damage in plate-like structures, SHM technology based on guided Lamb wave (GLW) interrogation is becoming more attractive due to its potential benefits such as large inspection area coverage in short time, simple inspection mechanism, and sensitivity to small damage. However, the GLW method has a few critical issues such as dispersion nature, mode conversion and separation, and multiple-mode existence. Phased array technique widely used in all aspects of civil, military, science, and medical industry fields may be employed to resolve the drawbacks of the GLW method. The GLW-based phased array approach is able to effectively examine and analyze complicated structural vibration responses in thin plate structures. Because the phased sensor array operates as a spatial filter for the GLW signals, the array signal processing method can enhance a desired signal component at a specific direction while eliminating other signal components from other directions. This dissertation presents the development, the experimental validation, and the damage detection applications of an innovative signal processing algorithm based on two-dimensional (2-D) spiral phased array in conjunction with the GLW interrogation technique. It starts with general backgrounds of SHM and the associated technology including the GLW interrogation method. Then, it is focused on the fundamentals of the GLW-based phased array approach and the development of an innovative signal processing algorithm associated with the 2-D spiral phased sensor array. The SHM approach based on array responses determined by the proposed phased array algorithm implementation is addressed. The experimental validation of the GLW-based 2-D spiral phased array technology and the associated damage detection applications to thin isotropic plate and anisotropic composite plate structures are presented.

High-sensitivity strain visualization using electroluminescence technologies

NASA Astrophysics Data System (ADS)

Xu, Jian; Jo, Hongki

2016-04-01

Visualizing mechanical strain/stress changes is an emerging area in structural health monitoring. Several ways are available for strain change visualization through the color/brightness change of the materials subjected to the mechanical stresses, for example, using mechanoluminescence (ML) materials and mechanoresponsive polymers (MRP). However, these approaches were not effectively applicable for civil engineering system yet, due to insufficient sensitivity to low-level strain of typical civil structures and limitation in measuring both static and dynamic strain. In this study, design and validation for high-sensitivity strain visualization using electroluminescence technologies are presented. A high-sensitivity Wheatstone bridge, of which bridge balance is precisely controllable circuits, is used with a gain-adjustable amplifier. The monochrome electroluminescence (EL) technology is employed to convert both static and dynamic strain change into brightness/color change of the EL materials, through either brightness change mode (BCM) or color alternation mode (CAM). A prototype has been made and calibrated in lab, the linearity between strain and brightness change has been investigated.

Methods for forewarning of critical condition changes in monitoring civil structures

DOEpatents

Abercrombie, Robert K.; Hively, Lee M.

2013-04-02

Sensor modules (12) including accelerometers (20) are placed on a physical structure (10) and tri-axial accelerometer data is converted to mechanical power (P) data (41) which then processed to provide a forewarning (57) of a critical event concerning the physical structure (10). The forewarning is based on a number of occurrences of a composite measure of dissimilarity (C.sub.i) exceeding a forewarning threshold over a defined sampling time; and a forewarning signal (58) is provided to a human observer through a visual, audible or tangible signal. A forewarning of a structural failure can also be provided based on a number of occurrences of (C.sub.i) above a failure value threshold.

Role of nondestructive evaluation in civil aviation: historical development, current status, future challenges

NASA Astrophysics Data System (ADS)

Weber, Hans J.

1995-07-01

Nondestructive evaluation has been used in civil aviation for 50 years. Until the arrival of the jet era it was mostly applied to component inspection. Since the damage-tolerant design philosophy was introduced by mandate for large transport aircraft, it has become an integral part of their design and maintenance. In the near future its role in the maintenance of aging small transport aircraft is expected to grow significantly. The most important factor contributing to the growing importance of NDE is the fact that the industry has been operating its aircraft much longer than originally envisioned, making it necessary to carefully monitor their structural condition to assure their airworthiness. NDE is helping making it economically feasible to operate aircraft for extended life times. Another major factor is the increased use of advanced materials, such as composites. Again, monitoring has to assure integrity. More recently, in an industry which has become highly competitive, NDE is becoming an important tool in the quest for reducing maintenance costs. The importance of NDE is expected to grow further.

Assessing the value of information for long-term structural health monitoring

NASA Astrophysics Data System (ADS)

Pozzi, Matteo; Der Kiureghian, Armen

2011-04-01

In the field of Structural Health Monitoring, tests and sensing systems are intended as tools providing diagnoses, which allow the operator of the facility to develop an efficient maintenance plan or to require extraordinary measures on a structure. The effectiveness of these systems depends directly on their capability to guide towards the most optimal decision for the prevailing circumstances, avoiding mistakes and wastes of resources. Though this is well known, most studies only address the accuracy of the information gained from sensors without discussing economic criteria. Other studies evaluate these criteria separately, with only marginal or heuristic connection with the outcomes of the monitoring system. The concept of "Value of Information" (VoI) provides a rational basis to rank measuring systems according to a utility-based metric, which fully includes the decision-making process affected by the monitoring campaign. This framework allows, for example, an explicit assessment of the economical justifiability of adopting a sensor depending on its precision. In this paper we outline the framework for assessing the VoI, as applicable to the ranking of competitive measuring systems. We present the basic concepts involved, highlight issues related to monitoring of civil structures, address the problem of non-linearity of the cost-to-utility mapping, and introduce an approximate Monte Carlo approach suitable for the implementation of time-consuming predictive models.

Structural health monitoring using smart optical fiber sensors

NASA Astrophysics Data System (ADS)

Davies, Heddwyn; Everall, Lorna A.; Gallon, Andrew M.

2001-04-01

This paper describes the potential of a smart monitoring system, incorporating optical fiber sensing techniques, to provide important structural information to designers and users alike. This technology has application in all areas including aerospace, civil, maritime and automotive engineering. In order to demonstrate the capability of the sensing system it has been installed in a 35 m free-standing carbon fiber yacht mast, where a complete optical network of strain and temperature sensors were embedded into a composite mast and boom during lay-up. The system was able to monitor the behavior of the composite rig through a range of handling conditions and the resulting strain information could be used by engineers to improve the structural design process. The optical strain sensor system comprises of three main components: the sensor network, the opto-electronic data acquisition unit (OFSSS) and the external PC which acts as a data log and display. Embedded fiber optic sensors have wide ranging application for structural load monitoring. Due to their small size, optical fiber sensors can be readily embedded into composite materials. Other advantages include their immediate multiplexing capability and immunity to electromagnetic interference. The capability of this system has been demonstrated within the maritime environment, but can be adapted for any application.

33 CFR 222.4 - Reporting earthquake effects.

Code of Federal Regulations, 2011 CFR

2011-07-01

... structural integrity and operational adequacy of major Civil Works structures following the occurrence of...) Applicability. This regulation is applicable to all field operating agencies having Civil Works responsibilities... 631, Vicksburg, Mississippi 39180. (d) Policy. Civil Works structures which could be caused to fail or...

33 CFR 222.4 - Reporting earthquake effects.

Code of Federal Regulations, 2014 CFR

2014-07-01

... structural integrity and operational adequacy of major Civil Works structures following the occurrence of...) Applicability. This regulation is applicable to all field operating agencies having Civil Works responsibilities... 631, Vicksburg, Mississippi 39180. (d) Policy. Civil Works structures which could be caused to fail or...

Effects of Piezoelectric (PZT) Sensor Bonding and the Characteristics of the Host Structure on Impedance Based Structural Health Monitoring

NASA Technical Reports Server (NTRS)

Jalloh, Abdul

2005-01-01

This study was conducted to investigate the effects of certain factors on the impedance signal in structural health monitoring. These factors were: the quality of the bond between the sensor and the host structure, and the characteristics of the host structure, such as geometry, mass, and material properties. This work was carried out to answer a set of questions, related to these factors, that were developed by the project team. The project team was comprised of Dr. Doug Ramers and Dr. Abdul Jalloh of the Summer Faculty Fellowship Program, Mr. Arnaldo Colon- Perez, a student intern from the University of Puerto Rico of Turabo, and Mr. John Lassiter and Mr. Bob Engberg of the Structural and Dynamics Test Group at NASA Marshall Space Flight Center (MSFC). This study was based on a review of the literature on structural health monitoring to investigate the factors referred to above because there was not enough time to plan and conduct the appropriate tests at MSFC during the tenure of the Summer Faculty Fellowship Program project members. The surveyed literature documents works on structural health monitoring that were based on laboratory tests that were conducted using bolted trusses and other civil engineering type structures for the most part. These are not the typical types of structures used in designing and building NASA s space vehicles and systems. It was therefore recommended that tests be conducted using NASA type structures, such as pressure vessels, to validate the observations made in this report.

Structural health monitoring to detect the presence, location and magnitude of structural damage in cadaveric porcine spines.

PubMed

Kawchuk, Gregory Neil; Decker, Colleen; Dolan, Ryan; Carey, Jason

2009-01-19

Structural health monitoring has been used successfully to identify defects in civil infrastructure and aerospace applications. Given that the majority of low back pain is thought to be mechanical in nature, our objective was to determine if structural health monitoring techniques could be employed successfully to identify the presence, location and magnitude of structural alterations within the spine. In six eviscerated cadaveric pigs, bone screws were drilled into the anterior bodies of L1-L5 and tri-axial accelerometers fixed to each spinous process. Vibration was then applied to the L3 spinous and frequency response functions obtained from each sensor axis before and after specific alterations of spinal structure. These alterations were produced at four unique locations and included (1) use of a cable tie to link anterior bone pins together and (2) progressive disc sectioning. Eighty percent of all data were used to train a neural network while the remaining data were used to test the network's ability to distinguish between structural states. The presence, location and magnitude of structural change within the spine was identified correctly in 5030/5040 possible neural network decisions. The diagnostic sensitivity and specificity of this technique ranged from 0.994 to 1.000. These results indicate that there is sufficient information embedded in frequency response data to identify the presence, location and magnitude of specific structural changes in the spine. If these techniques can be evolved for human use, structural health monitoring may provide a new approach toward understanding the underlying relations between spinal structure and function.

TOPICAL REVIEW: Smart aggregates: multi-functional sensors for concrete structures—a tutorial and a review

NASA Astrophysics Data System (ADS)

Song, Gangbing; Gu, Haichang; Mo, Yi-Lung

2008-06-01

This paper summarizes the authors' recent pioneering research work in piezoceramic-based smart aggregates and their innovative applications in concrete civil structures. The basic operating principle of smart aggregates is first introduced. The proposed smart aggregate is formed by embedding a waterproof piezoelectric patch with lead wires into a small concrete block. The proposed smart aggregates are multi-functional and can perform three major tasks: early-age concrete strength monitoring, impact detection and structural health monitoring. The proposed smart aggregates are embedded into the desired location before the casting of the concrete structure. The concrete strength development is monitored by observing the high frequency harmonic wave response of the smart aggregate. Impact on the concrete structure is detected by observing the open-circuit voltage of the piezoceramic patch in the smart aggregate. For structural health monitoring purposes, a smart aggregate-based active sensing system is designed for the concrete structure. Wavelet packet analysis is used as a signal-processing tool to analyze the sensor signal. A damage index based on the wavelet packet analysis is used to determine the structural health status. To better describe the time-history and location information of damage, two types of damage index matrices are proposed: a sensor-history damage index matrix and an actuator-sensor damage index matrix. To demonstrate the multi-functionality of the proposed smart aggregates, different types of concrete structures have been used as test objects, including concrete bridge bent-caps, concrete cylinders and a concrete frame. Experimental results have verified the effectiveness and the multi-functionality of the proposed smart aggregates. The multi-functional smart aggregates have the potential to be applied to the comprehensive monitoring of concrete structures from their earliest stages and throughout their lifetime.

Structural damage detection for in-service highway bridge under operational and environmental variability

NASA Astrophysics Data System (ADS)

Jin, Chenhao; Li, Jingcheng; Jang, Shinae; Sun, Xiaorong; Christenson, Richard

2015-03-01

Structural health monitoring has drawn significant attention in the past decades with numerous methodologies and applications for civil structural systems. Although many researchers have developed analytical and experimental damage detection algorithms through vibration-based methods, these methods are not widely accepted for practical structural systems because of their sensitivity to uncertain environmental and operational conditions. The primary environmental factor that influences the structural modal properties is temperature. The goal of this article is to analyze the natural frequency-temperature relationships and detect structural damage in the presence of operational and environmental variations using modal-based method. For this purpose, correlations between natural frequency and temperature are analyzed to select proper independent variables and inputs for the multiple linear regression model and neural network model. In order to capture the changes of natural frequency, confidence intervals to detect the damages for both models are generated. A long-term structural health monitoring system was installed on an in-service highway bridge located in Meriden, Connecticut to obtain vibration and environmental data. Experimental testing results show that the variability of measured natural frequencies due to temperature is captured, and the temperature-induced changes in natural frequencies have been considered prior to the establishment of the threshold in the damage warning system. This novel approach is applicable for structural health monitoring system and helpful to assess the performance of the structure for bridge management and maintenance.

Semi-Automated Air-Coupled Impact-Echo Method for Large-Scale Parkade Structure.

PubMed

Epp, Tyler; Svecova, Dagmar; Cha, Young-Jin

2018-03-29

Structural Health Monitoring (SHM) has moved to data-dense systems, utilizing numerous sensor types to monitor infrastructure, such as bridges and dams, more regularly. One of the issues faced in this endeavour is the scale of the inspected structures and the time it takes to carry out testing. Installing automated systems that can provide measurements in a timely manner is one way of overcoming these obstacles. This study proposes an Artificial Neural Network (ANN) application that determines intact and damaged locations from a small training sample of impact-echo data, using air-coupled microphones from a reinforced concrete beam in lab conditions and data collected from a field experiment in a parking garage. The impact-echo testing in the field is carried out in a semi-autonomous manner to expedite the front end of the in situ damage detection testing. The use of an ANN removes the need for a user-defined cutoff value for the classification of intact and damaged locations when a least-square distance approach is used. It is postulated that this may contribute significantly to testing time reduction when monitoring large-scale civil Reinforced Concrete (RC) structures.

Semi-Automated Air-Coupled Impact-Echo Method for Large-Scale Parkade Structure

PubMed Central

Epp, Tyler; Svecova, Dagmar; Cha, Young-Jin

2018-01-01

Structural Health Monitoring (SHM) has moved to data-dense systems, utilizing numerous sensor types to monitor infrastructure, such as bridges and dams, more regularly. One of the issues faced in this endeavour is the scale of the inspected structures and the time it takes to carry out testing. Installing automated systems that can provide measurements in a timely manner is one way of overcoming these obstacles. This study proposes an Artificial Neural Network (ANN) application that determines intact and damaged locations from a small training sample of impact-echo data, using air-coupled microphones from a reinforced concrete beam in lab conditions and data collected from a field experiment in a parking garage. The impact-echo testing in the field is carried out in a semi-autonomous manner to expedite the front end of the in situ damage detection testing. The use of an ANN removes the need for a user-defined cutoff value for the classification of intact and damaged locations when a least-square distance approach is used. It is postulated that this may contribute significantly to testing time reduction when monitoring large-scale civil Reinforced Concrete (RC) structures. PMID:29596332

Rock Slide Monitoring by Using TDR Inclinometers

NASA Astrophysics Data System (ADS)

Drusa, Marián; Bulko, Roman

2016-12-01

The geotechnical monitoring of the slope deformations is widespread at present time. In many geological localities and civil engineering construction areas, monitoring is a unique tool for controlling of negative factors and processes, also inform us about actual state of rock environment or interacting structures. It is necessary for risk assessment. In our case, geotechnical monitoring is controlling rockslide activity around in the future part of motorway. The construction of new highway route D1 from Bratislava to Košice crosses the territory which is affected by a massive rockslide close to Kraľovany village. There was a need to monitor the activity of a large unstable rockslide with deep shear planes. In this case of underground movement activity, the Department of Geotechnics of the University of Žilina installed inclinometers at the unstable area which worked on Time Domain Reflectometry (TDR) principle. Based on provided measurements, effectivity and suitability of TDR inclinometers for monitoring of deep underground movement activity is demonstrated.

Application of Multiplexed FBG and PZT Impedance Sensors for Health Monitoring of Rocks.

PubMed

Yang, Yaowen; Annamdas, Venu Gopal Madhav; Wang, Chao; Zhou, Yingxin

2008-01-21

Reliable structural health monitoring (SHM) including nondestructiveevaluation (NDE) is essential for safe operation of infrastructure systems. Effectivemonitoring of the rock components of civil infrastructures such as tunnels and cavernsremains challenging. The feasibility of employing smart optical fibre sensor (OFS) andpiezoelectric impedance sensor made up of lead zirconate titanate (PZT) forcomprehensive health monitoring of rocks, covering load history monitoring/retrieval aswell as damage assessment is presented in this paper. The rock specimens are subjected tocyclic loading and their conditions are continuously monitored using OFS and PZTsensors. OFS based multiplexed fibre Bragg grating (FBG) sensors are surface bonded onthe rock specimens. Their strain sensing performance is compared with the conventionalelectric strain gauges (ESGs). In addition, PZT patches are also bonded on the specimensto study the damage pattern during different loading cycles. Unlike the FBGs or ESGs,PZT patches are used as bi-functional sensors and actuators, enabling them to be efficientdetectors of incipient damages using the principle of electromechanical impedance. Theexperimental study demonstrated superior performance of these smart FBG and PZTimpedance sensors. This work is expected to be useful for SHM based NDE application ofrock structures such as caverns and tunnels.

Smart acoustic emission system for wireless monitoring of concrete structures

NASA Astrophysics Data System (ADS)

Yoon, Dong-Jin; Kim, Young-Gil; Kim, Chi-Yeop; Seo, Dae-Cheol

2008-03-01

Acoustic emission (AE) has emerged as a powerful nondestructive tool to detect preexisting defects or to characterize failure mechanisms. Recently, this technique or this kind of principle, that is an in-situ monitoring of inside damages of materials or structures, becomes increasingly popular for monitoring the integrity of large structures. Concrete is one of the most widely used materials for constructing civil structures. In the nondestructive evaluation point of view, a lot of AE signals are generated in concrete structures under loading whether the crack development is active or not. Also, it was required to find a symptom of damage propagation before catastrophic failure through a continuous monitoring. Therefore we have done a practical study in this work to fabricate compact wireless AE sensor and to develop diagnosis system. First, this study aims to identify the differences of AE event patterns caused by both real damage sources and the other normal sources. Secondly, it was focused to develop acoustic emission diagnosis system for assessing the deterioration of concrete structures such as a bridge, dame, building slab, tunnel etc. Thirdly, the wireless acoustic emission system was developed for the application of monitoring concrete structures. From the previous laboratory study such as AE event patterns analysis under various loading conditions, we confirmed that AE analysis provided a promising approach for estimating the condition of damage and distress in concrete structures. In this work, the algorithm for determining the damage status of concrete structures was developed and typical criteria for decision making was also suggested. For the future application of wireless monitoring, a low energy consumable, compact, and robust wireless acoustic emission sensor module was developed and applied to the concrete beam for performance test. Finally, based on the self-developed diagnosis algorithm and compact wireless AE sensor, new AE system for practical AE diagnosis was demonstrated for assessing the conditions of damage and distress in concrete structures.

Nondestructive evaluation of concrete structures by nonstationary thermal wave imaging

NASA Astrophysics Data System (ADS)

Mulaveesala, Ravibabu; Panda, Soma Sekhara Balaji; Mude, Rupla Naik; Amarnath, Muniyappa

2012-06-01

Reinforced concrete structures (RCS) have potential application in civil engineering and with the advent of nuclear engineering RCS to be capable enough to withstanding a variety of adverse environmental conditions. However, failures/loss of durability of designed structures due to premature reinforcement corrosion of rebar is a major constrain. Growing concern of safety of structure due to pre-mature deterioration has led to a great demand for development of non-destructive and non-contact testing techniques for monitoring and assessing health of RCS. This paper presents an experimental investigation of rebar corrosion by non-stationary thermal wave imaging. Experimental results have been proven, proposed approach is an effective technique for identification of corrosion in rebar in the concrete samples.

Analysis of the Civil-Military Relationship To Improve Efficacy And Coordination Of Humanitarian Aid And Disaster Relief Efforts

DTIC Science & Technology

2017-06-01

high. One factor that contributed to success was cross- fertilization of skills.  NDMA is a hybrid organization with officers from military, civil...Majeed Raja, Fahad Irshad, and Donny Bayu Sukarno 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000...8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING /MONITORING AGENCY NAME(S) AND ADDRESS(ES) N/A 10. SPONSORING / MONITORING AGENCY

Carbon fiber epoxy composites for both strengthening and health monitoring of structures.

PubMed

Salvado, Rita; Lopes, Catarina; Szojda, Leszek; Araújo, Pedro; Gorski, Marcin; Velez, Fernando José; Castro-Gomes, João; Krzywon, Rafal

2015-05-06

This paper presents a study of the electrical and mechanical behavior of several continuous carbon fibers epoxy composites for both strengthening and monitoring of structures. In these composites, the arrangement of fibers was deliberately diversified to test and understand the ability of the composites for self-sensing low strains. Composites with different arrangements of fibers and textile weaves, mainly unidirectional continuous carbon reinforced composites, were tested at the dynamometer. A two-probe method was considered to measure the relative electrical resistance of these composites during loading. The measured relative electrical resistance includes volume and contact electrical resistances. For all tested specimens, it increases with an increase in tensile strain, at low strain values. This is explained by the improved alignment of fibers and resulting reduction of the number of possible contacts between fibers during loading, increasing as a consequence the contact electrical resistance of the composite. Laboratory tests on strengthening of structural elements were also performed, making hand-made composites by the "wet process", which is commonly used in civil engineering for the strengthening of all types of structures in-situ. Results show that the woven epoxy composite, used for strengthening of concrete elements is also able to sense low deformations, below 1%. Moreover, results clearly show that this textile sensor also improves the mechanical work of the strengthened structural elements, increasing their bearing capacity. Finally, the set of obtained results supports the concept of a textile fabric capable of both structural upgrade and self-monitoring of structures, especially large structures of difficult access and needing constant, sometimes very expensive, health monitoring.

Carbon Fiber Epoxy Composites for Both Strengthening and Health Monitoring of Structures

PubMed Central

Salvado, Rita; Lopes, Catarina; Szojda, Leszek; Araújo, Pedro; Gorski, Marcin; Velez, Fernando José; Castro-Gomes, João; Krzywon, Rafal

2015-01-01

This paper presents a study of the electrical and mechanical behavior of several continuous carbon fibers epoxy composites for both strengthening and monitoring of structures. In these composites, the arrangement of fibers was deliberately diversified to test and understand the ability of the composites for self-sensing low strains. Composites with different arrangements of fibers and textile weaves, mainly unidirectional continuous carbon reinforced composites, were tested at the dynamometer. A two-probe method was considered to measure the relative electrical resistance of these composites during loading. The measured relative electrical resistance includes volume and contact electrical resistances. For all tested specimens, it increases with an increase in tensile strain, at low strain values. This is explained by the improved alignment of fibers and resulting reduction of the number of possible contacts between fibers during loading, increasing as a consequence the contact electrical resistance of the composite. Laboratory tests on strengthening of structural elements were also performed, making hand-made composites by the “wet process”, which is commonly used in civil engineering for the strengthening of all types of structures in-situ. Results show that the woven epoxy composite, used for strengthening of concrete elements is also able to sense low deformations, below 1%. Moreover, results clearly show that this textile sensor also improves the mechanical work of the strengthened structural elements, increasing their bearing capacity. Finally, the set of obtained results supports the concept of a textile fabric capable of both structural upgrade and self-monitoring of structures, especially large structures of difficult access and needing constant, sometimes very expensive, health monitoring. PMID:25954955

Application of Multiplexed FBG and PZT Impedance Sensors for Health Monitoring of Rocks

PubMed Central

Yang, Yaowen; Annamdas, Venu Gopal Madhav; Wang, Chao; Zhou, Yingxin

2008-01-01

Reliable structural health monitoring (SHM) including nondestructive evaluation (NDE) is essential for safe operation of infrastructure systems. Effective monitoring of the rock components of civil infrastructures such as tunnels and caverns remains challenging. The feasibility of employing smart optical fibre sensor (OFS) and piezoelectric impedance sensor made up of lead zirconate titanate (PZT) for comprehensive health monitoring of rocks, covering load history monitoring/retrieval as well as damage assessment is presented in this paper. The rock specimens are subjected to cyclic loading and their conditions are continuously monitored using OFS and PZT sensors. OFS based multiplexed fibre Bragg grating (FBG) sensors are surface bonded on the rock specimens. Their strain sensing performance is compared with the conventional electric strain gauges (ESGs). In addition, PZT patches are also bonded on the specimens to study the damage pattern during different loading cycles. Unlike the FBGs or ESGs, PZT patches are used as bi-functional sensors and actuators, enabling them to be efficient detectors of incipient damages using the principle of electromechanical impedance. The experimental study demonstrated superior performance of these smart FBG and PZT impedance sensors. This work is expected to be useful for SHM based NDE application of rock structures such as caverns and tunnels. PMID:27879708

Development of a wireless displacement measurement system using acceleration responses.

PubMed

Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo; Spencer, Billie F

2013-07-01

Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system.

Development of a Wireless Displacement Measurement System Using Acceleration Responses

PubMed Central

Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo; Spencer, Billie F.

2013-01-01

Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system. PMID:23881123

Fiber optic shape sensing for monitoring of flexible structures

NASA Astrophysics Data System (ADS)

Lally, Evan M.; Reaves, Matt; Horrell, Emily; Klute, Sandra; Froggatt, Mark E.

2012-04-01

Recent advances in materials science have resulted in a proliferation of flexible structures for high-performance civil, mechanical, and aerospace applications. Large aspect-ratio aircraft wings, composite wind turbine blades, and suspension bridges are all designed to meet critical performance targets while adapting to dynamic loading conditions. By monitoring the distributed shape of a flexible component, fiber optic shape sensing technology has the potential to provide valuable data during design, testing, and operation of these smart structures. This work presents a demonstration of such an extended-range fiber optic shape sensing technology. Three-dimensional distributed shape and position sensing is demonstrated over a 30m length using a monolithic silica fiber with multiple optical cores. A novel, helicallywound geometry endows the fiber with the capability to convert distributed strain measurements, made using Optical Frequency-Domain Reflectometry (OFDR), to a measurement of curvature, twist, and 3D shape along its entire length. Laboratory testing of the extended-range shape sensing technology shows

Study and Application of a Multi Magnetoresistor Sensor System to Detect Corrosion in Suspension Cables

NASA Astrophysics Data System (ADS)

Torres, V.; Quek, S.; Gaydecki, P.

2010-02-01

Aging and deterioration of the main functional parts in civil structures is one of the biggest problems that private and governmental institutions, dedicated to operate and maintain such structures, are facing now days. In the case of relatively old suspension bridges, problems emerge due to corrosion and break of wires in the main cables. Decisive information and a reliable monitoring and evaluation are factors of great relevance required to prevent significant or catastrophic damages caused to the structure, and more importantly, to people. The main challenge for the NDE methods of inspection arises in dealing with the steel wrapping barrier of the suspension cable, which main function is to shield, shape and hold the bundles. The following work, presents a study of a multi-Magnetoresistive sensors system aiming to support the monitoring and evaluation of suspension cables at some of its stages. Modelling, signal acquisition, signal processing, experiments and the initial phases of implementation are presented and discussed widely.

An investigation on wireless sensors for asset management and health monitoring of civil structures

NASA Astrophysics Data System (ADS)

Furkan, Mustafa; Mao, Qiang; Mazzotti, Matteo; DeVitis, John; Sumitro, S. Paul; Faridazar, Fred; Aktan, A. Emin; Moon, Franklin; Bartoli, Ivan

2016-04-01

Application of wireless sensors and sensor networks for Structural Health Monitoring has been investigated for a long time. Key limitations for practical use are energy requirements, connectivity, and integration with existing systems. Current sensors and sensor networks mainly rely on wired connectivity for communication and external power source for energy. This paper presents a suite of wireless sensors that are low-cost, maintenance free, rugged, and have long service life. The majority of the sensors considered were designed by transforming existing, proven, and robust wired sensors into wireless units. In this study, the wireless sensors were tested in laboratory conditions for calibration and evaluation along with wired sensors. The experimental results were also compared to theoretical results. The tests mostly show satisfactory performance of the wireless units. This work is part of a broader Federal Highway Administration sponsored project intended to ultimately validate a wireless sensing system on a real, operating structure to account for all the uncertainties, environmental conditions and operational variability that are encountered in the field.

Monitoring of civil infrastructures by interferometric radar: a review.

PubMed

Pieraccini, Massimiliano

2013-01-01

Ground-based radar interferometry is an increasingly popular technique for monitoring civil infrastructures. Many research groups, professionals, and companies have tested it in different operative scenarios, so it is time for a first systematic survey of the case studies reported in the literature. This review is addressed especially to the engineers and scientists interested to consider the applicability of the technique to their practice, so it is focused on the issues of the practical cases rather than on theory and principles, which are now well consolidated.

A Sensor Data Fusion System Based on k-Nearest Neighbor Pattern Classification for Structural Health Monitoring Applications

PubMed Central

Vitola, Jaime; Pozo, Francesc; Tibaduiza, Diego A.; Anaya, Maribel

2017-01-01

Civil and military structures are susceptible and vulnerable to damage due to the environmental and operational conditions. Therefore, the implementation of technology to provide robust solutions in damage identification (by using signals acquired directly from the structure) is a requirement to reduce operational and maintenance costs. In this sense, the use of sensors permanently attached to the structures has demonstrated a great versatility and benefit since the inspection system can be automated. This automation is carried out with signal processing tasks with the aim of a pattern recognition analysis. This work presents the detailed description of a structural health monitoring (SHM) system based on the use of a piezoelectric (PZT) active system. The SHM system includes: (i) the use of a piezoelectric sensor network to excite the structure and collect the measured dynamic response, in several actuation phases; (ii) data organization; (iii) advanced signal processing techniques to define the feature vectors; and finally; (iv) the nearest neighbor algorithm as a machine learning approach to classify different kinds of damage. A description of the experimental setup, the experimental validation and a discussion of the results from two different structures are included and analyzed. PMID:28230796

A Sensor Data Fusion System Based on k-Nearest Neighbor Pattern Classification for Structural Health Monitoring Applications.

PubMed

Vitola, Jaime; Pozo, Francesc; Tibaduiza, Diego A; Anaya, Maribel

2017-02-21

Civil and military structures are susceptible and vulnerable to damage due to the environmental and operational conditions. Therefore, the implementation of technology to provide robust solutions in damage identification (by using signals acquired directly from the structure) is a requirement to reduce operational and maintenance costs. In this sense, the use of sensors permanently attached to the structures has demonstrated a great versatility and benefit since the inspection system can be automated. This automation is carried out with signal processing tasks with the aim of a pattern recognition analysis. This work presents the detailed description of a structural health monitoring (SHM) system based on the use of a piezoelectric (PZT) active system. The SHM system includes: (i) the use of a piezoelectric sensor network to excite the structure and collect the measured dynamic response, in several actuation phases; (ii) data organization; (iii) advanced signal processing techniques to define the feature vectors; and finally; (iv) the nearest neighbor algorithm as a machine learning approach to classify different kinds of damage. A description of the experimental setup, the experimental validation and a discussion of the results from two different structures are included and analyzed.

A Noncontact FMCW Radar Sensor for Displacement Measurement in Structural Health Monitoring

PubMed Central

Li, Cunlong; Chen, Weimin; Liu, Gang; Yan, Rong; Xu, Hengyi; Qi, Yi

2015-01-01

This paper investigates the Frequency Modulation Continuous Wave (FMCW) radar sensor for multi-target displacement measurement in Structural Health Monitoring (SHM). The principle of three-dimensional (3-D) displacement measurement of civil infrastructures is analyzed. The requirements of high-accuracy displacement and multi-target identification for the measuring sensors are discussed. The fundamental measuring principle of FMCW radar is presented with rigorous mathematical formulas, and further the multiple-target displacement measurement is analyzed and simulated. In addition, a FMCW radar prototype is designed and fabricated based on an off-the-shelf radar frontend and data acquisition (DAQ) card, and the displacement error induced by phase asynchronism is analyzed. The conducted outdoor experiments verify the feasibility of this sensing method applied to multi-target displacement measurement, and experimental results show that three targets located at different distances can be distinguished simultaneously with millimeter level accuracy. PMID:25822139

A noncontact FMCW radar sensor for displacement measurement in structural health monitoring.

PubMed

Li, Cunlong; Chen, Weimin; Liu, Gang; Yan, Rong; Xu, Hengyi; Qi, Yi

2015-03-26

This paper investigates the Frequency Modulation Continuous Wave (FMCW) radar sensor for multi-target displacement measurement in Structural Health Monitoring (SHM). The principle of three-dimensional (3-D) displacement measurement of civil infrastructures is analyzed. The requirements of high-accuracy displacement and multi-target identification for the measuring sensors are discussed. The fundamental measuring principle of FMCW radar is presented with rigorous mathematical formulas, and further the multiple-target displacement measurement is analyzed and simulated. In addition, a FMCW radar prototype is designed and fabricated based on an off-the-shelf radar frontend and data acquisition (DAQ) card, and the displacement error induced by phase asynchronism is analyzed. The conducted outdoor experiments verify the feasibility of this sensing method applied to multi-target displacement measurement, and experimental results show that three targets located at different distances can be distinguished simultaneously with millimeter level accuracy.

Functionality Enhancement of Industrialized Optical Fiber Sensors and System Developed for Full-Scale Pavement Monitoring

PubMed Central

Wang, Huaping; Liu, Wanqiu; He, Jianping; Xing, Xiaoying; Cao, Dandan; Gao, Xipeng; Hao, Xiaowei; Cheng, Hongwei; Zhou, Zhi

2014-01-01

Pavements always play a predominant role in transportation. Health monitoring of pavements is becoming more and more significant, as frequently suffering from cracks, rutting, and slippage renders them prematurely out of service. Effective and reliable sensing elements are thus in high demand to make prognosis on the mechanical properties and occurrence of damage to pavements. Therefore, in this paper, various types of functionality enhancement of industrialized optical fiber sensors for pavement monitoring are developed, with the corresponding operational principles clarified in theory and the performance double checked by basic experiments. Furthermore, a self-healing optical fiber sensing network system is adopted to accomplish full-scale monitoring of pavements. The application of optical fiber sensors assembly and self-healing network system in pavement has been carried out to validate the feasibility. It has been proved that the research in this article provides a valuable method and meaningful guidance for the integrity monitoring of civil structures, especially pavements. PMID:24854060

Functionality enhancement of industrialized optical fiber sensors and system developed for full-scale pavement monitoring.

PubMed

Wang, Huaping; Liu, Wanqiu; He, Jianping; Xing, Xiaoying; Cao, Dandan; Gao, Xipeng; Hao, Xiaowei; Cheng, Hongwei; Zhou, Zhi

2014-05-19

Pavements always play a predominant role in transportation. Health monitoring of pavements is becoming more and more significant, as frequently suffering from cracks, rutting, and slippage renders them prematurely out of service. Effective and reliable sensing elements are thus in high demand to make prognosis on the mechanical properties and occurrence of damage to pavements. Therefore, in this paper, various types of functionality enhancement of industrialized optical fiber sensors for pavement monitoring are developed, with the corresponding operational principles clarified in theory and the performance double checked by basic experiments. Furthermore, a self-healing optical fiber sensing network system is adopted to accomplish full-scale monitoring of pavements. The application of optical fiber sensors assembly and self-healing network system in pavement has been carried out to validate the feasibility. It has been proved that the research in this article provides a valuable method and meaningful guidance for the integrity monitoring of civil structures, especially pavements.

Remote monitoring as a tool in condition assessment of a highway bridge

NASA Astrophysics Data System (ADS)

Tantele, Elia A.; Votsis, Renos A.; Onoufriou, Toula; Milis, Marios; Kareklas, George

2016-08-01

The deterioration of civil infrastructure and their subsequent maintenance is a significant problem for the responsible managing authorities. The ideal scenario is to detect deterioration and/or structural problems at early stages so that the maintenance cost is kept low and the safety of the infrastructure remains undisputed. The current inspection regimes implemented mostly via visual inspection are planned at specific intervals but are not always executed on time due to shortcomings in expert personnel and finance. However the introduction of technological advances in the assessment of infrastructures provides the tools to alleviate this problem. This study describes the assessment of a highway RC bridge's structural condition using remote structural health monitoring. A monitoring plan is implemented focusing on strain measurements; as strain is a parameter influenced by the environmental conditions supplementary data are provided from temperature and wind sensors. The data are acquired using wired sensors (deployed at specific locations) which are connected to a wireless sensor unit installed at the bridge. This WSN application enables the transmission of the raw data from the field to the office for processing and evaluation. The processed data are then used to assess the condition of the bridge. This case study, which is part of an undergoing RPF research project, illustrates that remote monitoring can alleviate the problem of missing structural inspections. Additionally, shows its potential to be the main part of a fully automated smart procedure of obtaining structural data, processed them and trigger an alarm when certain undesirable conditions are met.

Metadata and network API aspects of a framework for storing and retrieving civil infrastructure monitoring data

NASA Astrophysics Data System (ADS)

Wong, John-Michael; Stojadinovic, Bozidar

2005-05-01

A framework has been defined for storing and retrieving civil infrastructure monitoring data over a network. The framework consists of two primary components: metadata and network communications. The metadata component provides the descriptions and data definitions necessary for cataloging and searching monitoring data. The communications component provides Java classes for remotely accessing the data. Packages of Enterprise JavaBeans and data handling utility classes are written to use the underlying metadata information to build real-time monitoring applications. The utility of the framework was evaluated using wireless accelerometers on a shaking table earthquake simulation test of a reinforced concrete bridge column. The NEESgrid data and metadata repository services were used as a backend storage implementation. A web interface was created to demonstrate the utility of the data model and provides an example health monitoring application.

An automatic damage detection algorithm based on the Short Time Impulse Response Function

NASA Astrophysics Data System (ADS)

Auletta, Gianluca; Carlo Ponzo, Felice; Ditommaso, Rocco; Iacovino, Chiara

2016-04-01

Structural Health Monitoring together with all the dynamic identification techniques and damage detection techniques are increasing in popularity in both scientific and civil community in last years. The basic idea arises from the observation that spectral properties, described in terms of the so-called modal parameters (eigenfrequencies, mode shapes, and modal damping), are functions of the physical properties of the structure (mass, energy dissipation mechanisms and stiffness). Damage detection techniques traditionally consist in visual inspection and/or non-destructive testing. A different approach consists in vibration based methods detecting changes of feature related to damage. Structural damage exhibits its main effects in terms of stiffness and damping variation. Damage detection approach based on dynamic monitoring of structural properties over time has received a considerable attention in recent scientific literature. We focused the attention on the structural damage localization and detection after an earthquake, from the evaluation of the mode curvature difference. The methodology is based on the acquisition of the structural dynamic response through a three-directional accelerometer installed on the top floor of the structure. It is able to assess the presence of any damage on the structure providing also information about the related position and severity of the damage. The procedure is based on a Band-Variable Filter, (Ditommaso et al., 2012), used to extract the dynamic characteristics of systems that evolve over time by acting simultaneously in both time and frequency domain. In this paper using a combined approach based on the Fourier Transform and on the seismic interferometric analysis, an useful tool for the automatic fundamental frequency evaluation of nonlinear structures has been proposed. Moreover, using this kind of approach it is possible to improve some of the existing methods for the automatic damage detection providing stable results also during the strong motion phase. This approach helps to overcome the limitation derived from the use of techniques based on simple Fourier Transform that provide good results when the response of the monitored system is stationary, but fails when the system exhibits a non-stationary behaviour. The main advantage derived from the use of the proposed approach for Structural Health Monitoring is based on the simplicity of the interpretation of the nonlinear variations of the fundamental frequency. The proposed methodology has been tested on numerical models of reinforced concrete structures designed for only gravity loads without and with the presence of infill panels. In order to verify the effectiveness of the proposed approach for the automatic evaluation of the fundamental frequency over time, the results of an experimental campaign of shaking table tests conducted at the seismic laboratory of University of Basilicata (SISLAB) have been used. Acknowledgements This study was partially funded by the Italian Civil Protection Department within the project DPC-RELUIS 2015 - RS4 ''Seismic observatory of structures and health monitoring''. References Ditommaso, R., Mucciarelli, M., Ponzo, F.C. (2012) Analysis of non-stationary structural systems by using a band-variable filter. Bulletin of Earthquake Engineering. DOI: 10.1007/s10518-012-9338-y.

Distributed sensing of RC beams with HCFRP sensors

NASA Astrophysics Data System (ADS)

Yang, Caiqian; Wu, Zhishen; Ye, Lieping

2005-05-01

This paper addresses a novel type of hybrid carbon fiber-reinforced polymer (HCFRP) sensors suitable for the structural health monitoring (SHM) of civil engineering structures. The HCFRP sensors are composed of different types of carbon tows, which are active materials due to their electrical conductivity, piezoresistivity, excellent mechanical properties and resistance to corrosion. The HCFRP sensors are designed to comprise three types of carbon tows-high strength (HS), high modulus (HM) and middle modulus (MM), in order to realize a distributed and broad-based sensing function. Two types of HCFRP sensors, with and without pretreatment, are fabricated and investigated. The HCFRP sensors are bonded with epoxy resins on the bottom concrete surface of RC beam specimens to monitor the average strain, the initiation and propagation of cracks. The experimental results indicate that such kinds of sensors are characterized with broad-based and distributed sensing feasibilities. As a result, the structural health of the RC beams can be monitored and evaluated through characterizing the relationships between the change in electrical resistance of the HCFRP sensors, the average strain and the crack width of the RC beams. In addition, it is also revealed that the damages can also be located by properly adding the number of electrodes.

5 CFR 430.306 - Monitoring performance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Monitoring performance. 430.306 Section 430.306 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Managing Senior Executive Performance § 430.306 Monitoring performance. (a) Supervisors must...

5 CFR 430.306 - Monitoring performance.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Monitoring performance. 430.306 Section 430.306 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Managing Senior Executive Performance § 430.306 Monitoring performance. (a) Supervisors must...

5 CFR 430.306 - Monitoring performance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Monitoring performance. 430.306 Section 430.306 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Managing Senior Executive Performance § 430.306 Monitoring performance. (a) Supervisors must...

5 CFR 430.306 - Monitoring performance.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Monitoring performance. 430.306 Section 430.306 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Managing Senior Executive Performance § 430.306 Monitoring performance. (a) Supervisors must...

5 CFR 430.306 - Monitoring performance.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Monitoring performance. 430.306 Section 430.306 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Managing Senior Executive Performance § 430.306 Monitoring performance. (a) Supervisors must...

The Evolution of the Civil Affairs Force

DTIC Science & Technology

2013-12-01

efficiency. The purpose of the analysis is to determine whether the current Civil Affairs structure is the most efficient design , and if not, what changes...sources of data include the Total Army Analysis that was utilized to build the Civil Affairs force, historical Quadrennial Defense Reviews (QDR...efficiency. It addresses the question of whether the current Civil Affairs structure reflects the most efficient design , and if not, what changes are

Preload Monitoring of Bolted L-Shaped Lap Joints Using Virtual Time Reversal Method.

PubMed

Du, Fei; Xu, Chao; Wu, Guannan; Zhang, Jie

2018-06-13

L-shaped bolt lap joints are commonly used in aerospace and civil structures. However, bolt joints are frequently subjected to loosening, and this has a significant effect on the safety and reliability of these structures. Therefore, bolt preload monitoring is very important, especially at the early stage of loosening. In this paper, a virtual time reversal guided wave method is presented to monitor preload of bolted L-shaped lap joints accurately and simply. In this method, a referenced reemitting signal (RRS) is extracted from the bolted structure in fully tightened condition. Then the RRS is utilized as the excitation signal for the bolted structure in loosening states, and the normalized peak amplitude of refocused wave packet is used as the tightness index (TI A ). The proposed method is experimentally validated by L-shaped bolt joints with single and multiple bolts. Moreover, the selections of guided wave frequency and tightness index are also discussed. The results demonstrate that the relationship between TI A and bolt preload is linear. The detection sensitivity is improved significantly compared with time reversal (TR) method, particularly when bolt loosening is at its embryo stage. The results also show that TR method is an effective method for detection of the number of loosening bolts.

Continuous and embedded solutions for SHM of concrete structures using changing electrical potential in self-sensing cement-based composites

NASA Astrophysics Data System (ADS)

Downey, Austin; Garcia-Macias, Enrique; D'Alessandro, Antonella; Laflamme, Simon; Castro-Triguero, Rafael; Ubertini, Filippo

2017-04-01

Interest in the concept of self-sensing structural materials has grown in recent years due to its potential to enable continuous low-cost monitoring of next-generation smart-structures. The development of cement-based smart sensors appears particularly well suited for monitoring applications due to their numerous possible field applications, their ease of use and long-term stability. Additionally, cement-based sensors offer a unique opportunity for structural health monitoring of civil structures because of their compatibility with new or existing infrastructure. Particularly, the addition of conductive carbon nanofillers into a cementitious matrix provides a self-sensing structural material with piezoresistive characteristics sensitive to deformations. The strain-sensing ability is achieved by correlating the external loads with the variation of specific electrical parameters, such as the electrical resistance or impedance. Selection of the correct electrical parameter for measurement to correlate with features of interest is required for the condition assessment task. In this paper, we investigate the potential of using altering electrical potential in cement-based materials doped with carbon nanotubes to measure strain and detect damage in concrete structures. Experimental validation is conducted on small-scale specimens including a steel-reinforced beam of conductive cement paste. Comparisons are made with constant electrical potential and current methods commonly found in the literature. Experimental results demonstrate the ability of the changing electrical potential at detecting features important for assessing the condition of a structure.

A comparative study on book shelf structure based on different domain modal analysis

NASA Astrophysics Data System (ADS)

Sabamehr, Ardalan; Roy, Timir Baran; Bagchi, Ashutosh

2017-04-01

Structural Health Monitoring (SHM) based on the vibration of structures has been very attractive topic for researchers in different fields such as: civil, aeronautical and mechanical engineering. The aim of this paper is to compare three most common modal identification techniques such as Frequency Domain Decomposition (FDD), Stochastic Subspace Identification (SSI) and Continuous Wavelet Transform (CWT) to find modal properties (such as natural frequency, mode shape and damping ratio) of three story book shelf steel structure which was built in Concordia University Lab. The modified Complex Morlet wavelet have been selected for wavelet in order to use asymptotic signal rather than real one with variable bandwidth and wavelet central frequency. So, CWT is able to detect instantaneous modulus and phase by use of local maxima ridge detection.

Civil Applications of National Satellites

NASA Astrophysics Data System (ADS)

Killam, Dudley B.

2002-01-01

For over thirty years, the United States Air Force has employed infrared surveillance for missile warning purposes in support of peace. The Defense Support Program, currently employed in this way, consists of a constellation of satellites that provide civil-oriented, peace preserving infrared surveillance. Such civil applications include monitoring parched areas for wind-whipped brush fires or lightning-initiated forest fires that consume many acres of timber and threaten populated areas. Other applications include the similar monitoring of static, infrared-sensed heat sources including volcanoes and the plumes of acrid smoke produced when the volcanoes are active. This paper will address these important missions that can be performed by the national infrared surveillance satellite constellations, furthering the peace of the world in ways never envisioned by their creators 30 years ago.

Security challenge to using smartphones for SHM

NASA Astrophysics Data System (ADS)

Abueh, Yeka; Liu, Hong

2016-04-01

Pervasive smartphones have demonstrated great potential in structural health monitoring (SHM) of civil infrastructures. Their sensing, processing, and communication capabilities along with crowdsourcing facility ease technical difficulties and reduce financial burdens of instrumentation and monitoring for SHM in civil infrastructures. However, smartphones are vulnerable to unintentional misuses and malicious attacks. This paper analyzes the vulnerabilities of smartphones in performing SHM and reveals the exploitation of those vulnerabilities. The work probes the attack surface of both devices and data. Device attack scenarios include hacking individual smartphones to modify the data stored on them and orchestrating smartphones to launch a distributed denial-of-service attack. Specifically, experiments are conducted to remotely access an Android smartphone and modify the sensing data of structural health stored on it. The work also presents a case study that reveals the sensitivity of a popular perturbation analysis method to faulty data delivered by a smartphone. The paper provides the direction of meeting the security challenge to using smartphones for SHM. As the first line of defense, device authentication is implemented in the smartphone to stop spoofing. Subsequently, message authentication is devised to maintain data integrity. There is a need to apply data science for the SHM immunity system against the sensitivity to data inaccuracy. The work also evaluates the cost-effectiveness of the proposed security measures, recommending varying levels of security to mitigate the adversaries to smartphones used in SHM systems. It calls for security solutions at the design stage of SHM systems rather than patching up after their implementations.

Prevalence of drugs and alcohol in fatal civil aviation accidents between 1994 and 1998 : final report.

DOT National Transportation Integrated Search

2000-06-01

The use of drugs and alcohol in aviation is closely monitored by the FAA Office of Aviation Medicine's (OAMs) Civil Aeromedical Institute (CAMI) through the toxicological analysis of specimens from pilots who have died in aviation accidents. This ...

23 CFR 230.206 - Monitoring supportive services.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Monitoring supportive services. 230.206 Section 230.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Supportive Services for Minority, Disadvantaged, and Women Business Enterprises § 230.206 Monitoring...

23 CFR 230.206 - Monitoring supportive services.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Monitoring supportive services. 230.206 Section 230.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Supportive Services for Minority, Disadvantaged, and Women Business Enterprises § 230.206 Monitoring...

23 CFR 230.206 - Monitoring supportive services.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Monitoring supportive services. 230.206 Section 230.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Supportive Services for Minority, Disadvantaged, and Women Business Enterprises § 230.206 Monitoring...

23 CFR 230.206 - Monitoring supportive services.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Monitoring supportive services. 230.206 Section 230.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Supportive Services for Minority, Disadvantaged, and Women Business Enterprises § 230.206 Monitoring...

23 CFR 230.206 - Monitoring supportive services.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Monitoring supportive services. 230.206 Section 230.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Supportive Services for Minority, Disadvantaged, and Women Business Enterprises § 230.206 Monitoring...

Infrared thermography for condition monitoring - A review

NASA Astrophysics Data System (ADS)

Bagavathiappan, S.; Lahiri, B. B.; Saravanan, T.; Philip, John; Jayakumar, T.

2013-09-01

Temperature is one of the most common indicators of the structural health of equipment and components. Faulty machineries, corroded electrical connections, damaged material components, etc., can cause abnormal temperature distribution. By now, infrared thermography (IRT) has become a matured and widely accepted condition monitoring tool where the temperature is measured in real time in a non-contact manner. IRT enables early detection of equipment flaws and faulty industrial processes under operating condition thereby, reducing system down time, catastrophic breakdown and maintenance cost. Last three decades witnessed a steady growth in the use of IRT as a condition monitoring technique in civil structures, electrical installations, machineries and equipment, material deformation under various loading conditions, corrosion damages and welding processes. IRT has also found its application in nuclear, aerospace, food, paper, wood and plastic industries. With the advent of newer generations of infrared camera, IRT is becoming a more accurate, reliable and cost effective technique. This review focuses on the advances of IRT as a non-contact and non-invasive condition monitoring tool for machineries, equipment and processes. Various conditions monitoring applications are discussed in details, along with some basics of IRT, experimental procedures and data analysis techniques. Sufficient background information is also provided for the beginners and non-experts for easy understanding of the subject.

Ageing management of french NPP civil work structures

NASA Astrophysics Data System (ADS)

Gallitre, E.; Dauffer, D.

2011-04-01

This paper presents EDF practice about concrete structure ageing management, from the mechanisms analysis to the formal procedure which allows the French company to increase 900 MWe NPP lifetime until 40 years; it will also introduce its action plan for 60 years lifetime extension. This practice is based on a methodology which identifies every ageing mechanism; both plants feedback and state of the art are screened and conclusions are drawn up into an "ageing analysis data sheet". That leads at first to a collection of 57 data sheets which give the mechanism identification, the components that are concerned and an analysis grid which is designed to assess the safety risk. This analysis screens the reference documents describing the mechanism, the design lifetime hypotheses, the associated regulation or codification, the feedback experiences, the accessibility, the maintenance actions, the repair possibility and so one. This analysis has to lead to a conclusion about the risk taking into account monitoring and maintenance. If the data sheet conclusion is not clear enough, then a more detailed report is launched. The technical document which is needed, is a formal detailed report which summarizes every theoretical knowledge and monitoring data: its objective is to propose a solution for ageing management: this solution can include more inspections or specific research development, or additional maintenance. After a first stage on the 900 MWe units, only two generic ageing management detailed reports have been needed for the civil engineering part: one about reactor building containment, and one about other structures which focuses on concrete inflating reactions. The second stage consists on deriving this generic analysis (ageing mechanism and detailed reports) to every plant where a complete ageing report is required (one report for all equipments and structures of the plant, but specific for each reactor). This ageing management is a continuous process because the 57 generic data sheets set is updated every year and the detailed generic reports every five years. After this 40 year lifetime extension, EDF is preparing a 60 years lifetime action plan which includes R&D actions, specific industrial studies and also monitoring improvements.

A wireless fatigue monitoring system utilizing a bio-inspired tree ring data tracking technique.

PubMed

Bai, Shi; Li, Xuan; Xie, Zhaohui; Zhou, Zhi; Ou, Jinping

2014-03-05

Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is proposed. The general framework, methodology, and verification of this intelligent system are discussed in details. The rain-flow counting (RFC) method is adopted as the core algorithm which quantifies fatigue damages, and Digital Signal Processing (DSP) is introduced as the core module for data collection and analysis. Laboratory test results based on strain gauges and polyvinylidene fluoride (PVDF) sensors have shown that the developed intelligent system can provide a reliable quick feedback and early warning of fatigue failure. With the merits of low cost, high accuracy and great reliability, the developed wireless fatigue sensing system can be further applied to mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, etc.

Enhanced Aircraft Platform Availability Through Advanced Maintenance Concepts and Technologies (Amelioration de la Disponibilite des Plateformes D’Aeronefs par L’Utilisation des Technologies et des Concepts Evolues de Maintenance)

DTIC Science & Technology

2011-06-01

DeLong, W., Yepez, S., Reedy, D. and White, S., “Use of Composite Materials, Health Monitoring and Self Healing Concepts to Refurbish our Civil and...Health Monitoring and Self Healing Concepts to Refurbish Our Civil and Military Infrastructure”, Sandia National Laboratories Report SAND2007-5547...failure without the need for the system to go off-line. Recovery Blocks and Self - Healing (Software) The backwards

Monitoring of Civil Infrastructures by Interferometric Radar: A Review

PubMed Central

Pieraccini, Massimiliano

2013-01-01

Ground-based radar interferometry is an increasingly popular technique for monitoring civil infrastructures. Many research groups, professionals, and companies have tested it in different operative scenarios, so it is time for a first systematic survey of the case studies reported in the literature. This review is addressed especially to the engineers and scientists interested to consider the applicability of the technique to their practice, so it is focused on the issues of the practical cases rather than on theory and principles, which are now well consolidated. PMID:24106454

Metrics to Monitor Governance and Reconstruction in Afghanistan: Development of Measures of Effectiveness for Civil-Military Operations and a Standardized Tool to Monitor Governance Quality

DTIC Science & Technology

2004-03-12

18:77-87 (1995). Bryman A. The debate about quantitative and qualitative research : a question of method or epistemology. British Journal of...the AGQI may be used with any category of person. The design is consistent with accepted procedures for social science research of this type ( Bryman ...operations in Afghanistan. This report documents: 1) methods to develop MOE, which may be used to the develop MOE for any type of operation; 2) the civil

Tapping and listening: a new approach to bolt looseness monitoring

NASA Astrophysics Data System (ADS)

Kong, Qingzhao; Zhu, Junxiao; Ho, Siu Chun Michael; Song, Gangbing

2018-07-01

Bolted joints are among the most common building blocks used across different types of structures, and are often the key components that sew all other structural parts together. Monitoring and assessment of looseness in bolted structures is one of the most attractive topics in mechanical, aerospace, and civil engineering. This paper presents a new percussion-based non-destructive approach to determine the health condition of bolted joints with the help of machine learning. The proposed method is very similar to the percussive diagnostic techniques used in clinical examinations to diagnose the health of patients. Due to the different interfacial properties among the bolts, nuts and the host structure, bolted joints can generate unique sounds when it is excited by impacts, such as from tapping. Power spectrum density, as a signal feature, was used to recognize and classify recorded tapping data. A machine learning model using the decision tree method was employed to identify the bolt looseness level. Experiments demonstrated that the newly proposed method for bolt looseness detection is very easy to implement by ‘listening to tapping’ and the monitoring accuracy is very high. With the rapid in robotics, the proposed approach has great potential to be implemented with intimately weaving robotics and machine learning to produce a cyber-physical system that can automatically inspect and determine the health of a structure.

Structural health monitoring feature design by genetic programming

NASA Astrophysics Data System (ADS)

Harvey, Dustin Y.; Todd, Michael D.

2014-09-01

Structural health monitoring (SHM) systems provide real-time damage and performance information for civil, aerospace, and other high-capital or life-safety critical structures. Conventional data processing involves pre-processing and extraction of low-dimensional features from in situ time series measurements. The features are then input to a statistical pattern recognition algorithm to perform the relevant classification or regression task necessary to facilitate decisions by the SHM system. Traditional design of signal processing and feature extraction algorithms can be an expensive and time-consuming process requiring extensive system knowledge and domain expertise. Genetic programming, a heuristic program search method from evolutionary computation, was recently adapted by the authors to perform automated, data-driven design of signal processing and feature extraction algorithms for statistical pattern recognition applications. The proposed method, called Autofead, is particularly suitable to handle the challenges inherent in algorithm design for SHM problems where the manifestation of damage in structural response measurements is often unclear or unknown. Autofead mines a training database of response measurements to discover information-rich features specific to the problem at hand. This study provides experimental validation on three SHM applications including ultrasonic damage detection, bearing damage classification for rotating machinery, and vibration-based structural health monitoring. Performance comparisons with common feature choices for each problem area are provided demonstrating the versatility of Autofead to produce significant algorithm improvements on a wide range of problems.

Measuring Access to Learning Opportunities.

ERIC Educational Resources Information Center

Hawley, Willis D., Ed.; Ready, Timothy, Ed.

This study examined the continued relevance and adequacy of the Elementary and Secondary School Civil Rights Compliance Report (E&S Survey) as a tool for enforcing civil rights laws in education, monitoring quality of access to learning opportunities, and research on other current issues of educational policy and practice. The Committee on…

Structural health monitoring of the Gröndals Bridge in Sweden: the behaviour of CFRP strengthening in cold temperature

NASA Astrophysics Data System (ADS)

Hejll, Arvid; Täljsten, Björn; Carolin, Anders

2006-03-01

To obtain a better knowledge of existing structures behaviour monitoring can be used. The use of monitoring in bridge structures by the use of instruments to assess the integrity of structures is not new and there are reports from structures tested as early as in the 19th century according to ISIS Canada1 However, the term SHM (Structural Health Monitoring) is relatively new to civil engineering and the driving force to implement SHM comes from recognising the limitations of conventional visual inspections and evaluations using conservative codes of practice. The possibilities to monitor existing structures with help of the rapidly evolving Information Technology are to day carried out. The objective of SHM is to monitor the in-situ behaviour of a structure accurately and efficiently, to assess its performance under various service conditions, to detect damage or deterioration, and to determine the health or condition of the structure1. In Sweden strengthening and periodic monitoring of a large freivorbau bridge (pre-stresed concrete box girder bridge) has been carried out, the Gröndals Bridge. The bridge is located in Stockholm and is approximately 400 m in length with a free span of 120 m. It was opened to tram traffic in year 2000. Just after opening cracks were noticed in the webs, these cracks have then increased, the size of the largest cracks exceeded 0.5 mm, and at the end of year 2001 the bridge was temporarily strengthened. This was carried out with externally placed prestressed steel stays. The reason for cracking is quite clear but the responsibility is still debated. Nevertheless, it was evidently that the bridge needed to be strengthened. The strengthening methods used were CFRP plates in the Service Limit State (SLS) and prestressed dywidag stays in the Ultimate Limit State (ULS). The strengthening was carried out during year 2002. At the same time monitoring of the bridge commenced, using LVDT crack gauges as well as optical fibre sensors. This monitoring was carried out during the summer period. In addition to this a winter monitoring was carried out in the beginning of 2005. This paper presents the background to strengthening and a comparison between summer and winter monitoring where the strengthening behaviour between the two seasons is enlightened. The result from the monitoring is very interesting; it would have been preferable to strengthen the bridge during the winter.

5 CFR 575.212 - Internal monitoring requirements and revocation or suspension of authority.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Internal monitoring requirements and... MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, RELOCATION, AND RETENTION INCENTIVES; SUPERVISORY DIFFERENTIALS; AND EXTENDED ASSIGNMENT INCENTIVES Relocation Incentives § 575.212 Internal monitoring...

5 CFR 575.312 - Internal monitoring requirements and revocation or suspension of authority.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Internal monitoring requirements and... MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, RELOCATION, AND RETENTION INCENTIVES; SUPERVISORY DIFFERENTIALS; AND EXTENDED ASSIGNMENT INCENTIVES Retention Incentives § 575.312 Internal monitoring...

Structural engineering masters level education framework of knowledge for the needs of initial professional practice

NASA Astrophysics Data System (ADS)

Balogh, Zsuzsa Enriko

For at least the last decade, engineering, civil engineering, along with structural engineering as a profession within civil engineering, have and continue to face an emerging need for "Raising the Bar" of preparedness of young engineers seeking to become practicing professional engineers. The present consensus of the civil engineering profession is that the increasing need for broad and in-depth knowledge should require the young structural engineers to have at least a Masters-Level education. This study focuses on the Masters-Level preparedness in the structural engineering area within the civil engineering field. It follows much of the methodology used in the American Society of Civil Engineers (ASCE) Body of Knowledge determination for civil engineering and extends this type of study to better define the portion of the young engineers preparation beyond the undergraduate program for one specialty area of civil engineering. The objective of this research was to create a Framework of Knowledge for the young engineer which identifies and recognizes the needs of the profession, along with the profession's expectations of how those needs can be achieved in the graduate-level academic setting, in the practice environment, and through lifelong learning opportunities with an emphasis on the initial five years experience past completion of a Masters program in structural engineering. This study applied a modified Delphi method to obtain the critical information from members of the structural engineering profession. The results provide a Framework of Knowledge which will be useful to several groups seeking to better ensure the preparedness of the future young structural engineers at the Masters-Level.

A Wireless MEMS-Based Inclinometer Sensor Node for Structural Health Monitoring

PubMed Central

Ha, Dae Woong; Park, Hyo Seon; Choi, Se Woon; Kim, Yousok

2013-01-01

This paper proposes a wireless inclinometer sensor node for structural health monitoring (SHM) that can be applied to civil engineering and building structures subjected to various loadings. The inclinometer used in this study employs a method for calculating the tilt based on the difference between the static acceleration and the acceleration due to gravity, using a micro-electro-mechanical system (MEMS)-based accelerometer. A wireless sensor node was developed through which tilt measurement data are wirelessly transmitted to a monitoring server. This node consists of a slave node that uses a short-distance wireless communication system (RF 2.4 GHz) and a master node that uses a long-distance telecommunication system (code division multiple access—CDMA). The communication distance limitation, which is recognized as an important issue in wireless monitoring systems, has been resolved via these two wireless communication components. The reliability of the proposed wireless inclinometer sensor node was verified experimentally by comparing the values measured by the inclinometer and subsequently transferred to the monitoring server via wired and wireless transfer methods to permit a performance evaluation of the wireless communication sensor nodes. The experimental results indicated that the two systems (wired and wireless transfer systems) yielded almost identical values at a tilt angle greater than 1°, and a uniform difference was observed at a tilt angle less than 0.42° (approximately 0.0032° corresponding to 0.76% of the tilt angle, 0.42°) regardless of the tilt size. This result was deemed to be within the allowable range of measurement error in SHM. Thus, the wireless transfer system proposed in this study was experimentally verified for practical application in a structural health monitoring system. PMID:24287533

The role of civil society in strengthening intercultural maternal health care in local health facilities: Puno, Peru

PubMed Central

Samuel, Jeannie

2016-01-01

Background and objective Peru's Ministry of Health has made efforts to increase the cultural inclusiveness of maternal health services. In 2005, the Ministry adopted an intercultural birthing policy (IBP) that authorizes and encourages the use of culturally acceptable birthing practices in government-run health facilities. However, studies suggest that indigenous women may receive inconsistent benefits from these kinds of policies. This article examines whether a grassroots accountability initiative based on citizen monitoring of local health facilities by indigenous women can help to promote the objectives of the IBP and improve intercultural maternal health care. Design Findings are drawn from a larger qualitative research study completed in 2015 that included fieldwork done between 2010 and 2011. Semi-structured interviews were conducted with 23 women working as citizen monitors in local health facilities in Puno and 30 key informants, including frontline health workers, health officials, and civil society actors in Puno and Lima, and human rights lawyers from the Defensoría del Pueblo Office in Puno. Results Monitors confirmed from their own personal experiences in the 1990s and early 2000s that respect for intercultural aspects of maternal health care, including traditional indigenous birthing practices, were not readily accepted in publicly funded health facilities. It was also common for indigenous women to face discrimination when seeking health service provided by the state. Although the government's adoption of the IBP in 2005 was a positive step, considerable efforts are still needed to ensure high-quality, culturally appropriate maternal health care is consistently available in local health facilities. Conclusions Despite important progress in the past two decades, policies aimed at improving intercultural maternal health care are unevenly implemented in local health facilities. Civil society, in particular indigenous women themselves, can play an important role in holding the state accountable for quality care. PMID:27987298

Citizen sensors for SHM: use of accelerometer data from smartphones.

PubMed

Feng, Maria; Fukuda, Yoshio; Mizuta, Masato; Ozer, Ekin

2015-01-29

Ubiquitous smartphones have created a significant opportunity to form a low-cost wireless Citizen Sensor network and produce big data for monitoring structural integrity and safety under operational and extreme loads. Such data are particularly useful for rapid assessment of structural damage in a large urban setting after a major event such as an earthquake. This study explores the utilization of smartphone accelerometers for measuring structural vibration, from which structural health and post-event damage can be diagnosed. Widely available smartphones are tested under sinusoidal wave excitations with frequencies in the range relevant to civil engineering structures. Large-scale seismic shaking table tests, observing input ground motion and response of a structural model, are carried out to evaluate the accuracy of smartphone accelerometers under operational, white-noise and earthquake excitations of different intensity. Finally, the smartphone accelerometers are tested on a dynamically loaded bridge. The extensive experiments show satisfactory agreements between the reference and smartphone sensor measurements in both time and frequency domains, demonstrating the capability of the smartphone sensors to measure structural responses ranging from low-amplitude ambient vibration to high-amplitude seismic response. Encouraged by the results of this study, the authors are developing a citizen-engaging and data-analytics crowdsourcing platform towards a smartphone-based Citizen Sensor network for structural health monitoring and post-event damage assessment applications.

In-flight fiber optic acoustic emission sensor (FAESense) system for the real time detection, localization, and classification of damage in composite aircraft structures

NASA Astrophysics Data System (ADS)

Mendoza, Edgar; Prohaska, John; Kempen, Connie; Esterkin, Yan; Sun, Sunjian

2013-05-01

Acoustic emission sensing is a leading structural health monitoring technique use for the early warning detection of structural damage associated with impacts, cracks, fracture, and delaminations in advanced materials. Current AE systems based on electronic PZT transducers suffer from various limitations that prevent its wide dynamic use in practical avionics and aerospace applications where weight, size and power are critical for operation. This paper describes progress towards the development of a wireless in-flight distributed fiber optic acoustic emission monitoring system (FAESense™) suitable for the onboard-unattended detection, localization, and classification of damage in avionics and aerospace structures. Fiber optic AE sensors offer significant advantages over its counterpart electronic AE sensors by using a high-density array of micron-size AE transducers distributed and multiplex over long lengths of a standard single mode optical fiber. Immediate SHM applications are found in commercial and military aircraft, helicopters, spacecraft, wind mil turbine blades, and in next generation weapon systems, as well as in the petrochemical and aerospace industries, civil structures, power utilities, and a wide spectrum of other applications.

Test of FBG sensors for monitoring high pressure pipes

NASA Astrophysics Data System (ADS)

Paolozzi, Antonio; Paris, Claudio; Vendittozzi, Cristian; Felli, Ferdinando; Mongelli, Marialuisa; De Canio, Gerardo; Colucci, Alessandro; Asanuma, Hiroshi

2017-04-01

Fibre Bragg Grating (FBG) sensors are increasingly being used on a wide range of civil, industrial and aerospace structures. The sensors are created inside optical fibres (usually standard telecommunication fibres); the optical fibres technology allows to install the sensors on structures working in harsh environments, since the materials are almost insensitive to corrosion, the monitoring system can be positioned far away from the sensors without sensible signal losses, and there is no risk of electric discharge. FBG sensors can be used to create strain gages, thermometers or accelerometers, depending on the coating on the grating, on the way the grating is fixed to the structure, and on the presence of a specifically designed interface that can act as a transducer. This paper describes a test of several different FBG sensors to monitor an high pressure pipe that feeds the hydraulic actuators of a 6 degrees-of-freedom shaking table at the ENEA Casaccia research centre. A bare FBG sensor and a copper coated FBG sensor have been glued on the pipe. A third sensor has been mounted on a special interface to amplify the vibrations; this last sensor can be placed on the steel pipe by a magnetic mounting system, that also allows the its removal. All the sensor are placed parallel to the axis of the pipe. The analysis of the data recorded when the shaking table is operated will allow to determine which kind of sensor is best suited for structural monitoring of high pressure pipelines.

PREFACE: 2nd International Conference on Innovative Materials, Structures and Technologies

NASA Astrophysics Data System (ADS)

Ručevskis, Sandris

2015-11-01

The 2nd International Conference on Innovative Materials, Structures and Technologies (IMST 2015) took place in Riga, Latvia from 30th September - 2nd October, 2015. The first event of the conference series, dedicated to the 150th anniversary of the Faculty of Civil Engineering of Riga Technical University, was held in 2013. Following the established tradition, the aim of the conference was to promote and discuss the latest results of industrial and academic research carried out in the following engineering fields: analysis and design of advanced structures and buildings; innovative, ecological and energy efficient building materials; maintenance, inspection and monitoring methods; construction technologies; structural management; sustainable and safe transport infrastructure; and geomatics and geotechnics. The conference provided an excellent opportunity for leading researchers, representatives of the industrial community, engineers, managers and students to share the latest achievements, discuss recent advances and highlight the current challenges. IMST 2015 attracted over 120 scientists from 24 countries. After rigorous reviewing, over 80 technical papers were accepted for publication in the conference proceedings. On behalf of the organizing committee I would like to thank all the speakers, authors, session chairs and reviewers for their efficient and timely effort. The 2nd International Conference on Innovative Materials, Structures and Technologies was organized by the Faculty of Civil Engineering of Riga Technical University with the support of the Latvia State Research Programme under the grant agreement "INNOVATIVE MATERIALS AND SMART TECHNOLOGIES FOR ENVIRONMENTAL SAFETY, IMATEH". I would like to express sincere gratitude to Juris Smirnovs, Dean of the Faculty of Civil Engineering, and Andris Chate, manager of the Latvia State Research Programme. Finally, I would like to thank all those who helped to make this event happen. Special thanks go to Diana Bajare, Laura Sele, Liga Radina and Jana Galilejeva for their major contribution to organizing the conference and to the literary editor Tatjana Smirnova and technical editor Daira Erdmane for their hard work on the conference proceedings.

Bridge reliability assessment based on the PDF of long-term monitored extreme strains

NASA Astrophysics Data System (ADS)

Jiao, Meiju; Sun, Limin

2011-04-01

Structural health monitoring (SHM) systems can provide valuable information for the evaluation of bridge performance. As the development and implementation of SHM technology in recent years, the data mining and use has received increasingly attention and interests in civil engineering. Based on the principle of probabilistic and statistics, a reliability approach provides a rational basis for analysis of the randomness in loads and their effects on structures. A novel approach combined SHM systems with reliability method to evaluate the reliability of a cable-stayed bridge instrumented with SHM systems was presented in this paper. In this study, the reliability of the steel girder of the cable-stayed bridge was denoted by failure probability directly instead of reliability index as commonly used. Under the assumption that the probability distributions of the resistance are independent to the responses of structures, a formulation of failure probability was deduced. Then, as a main factor in the formulation, the probability density function (PDF) of the strain at sensor locations based on the monitoring data was evaluated and verified. That Donghai Bridge was taken as an example for the application of the proposed approach followed. In the case study, 4 years' monitoring data since the operation of the SHM systems was processed, and the reliability assessment results were discussed. Finally, the sensitivity and accuracy of the novel approach compared with FORM was discussed.

On the modal characteristics of damaging structures subjected to earthquakes

NASA Astrophysics Data System (ADS)

Carlo Ponzo, Felice; Ditommaso, Rocco; Auletta, Gianluca; Iacovino, Chiara; Mossucca, Antonello; Nigro, Antonella; Nigro, Domenico

2015-04-01

Structural Health Monitoring, especially for structures located in seismic prone areas, has assumed a meaning of great importance in last years, for the possibility to make a more objective and more rapid estimation of the damage occurred on buildings after a seismic event. In the last years many researchers are working to set-up new methodologies for Non-destructive Damage Evaluation based on the variation of the dynamic behaviour of structures under seismic loads. The NDE methods for damage detection and evaluation can be classified into four levels, according to the specific criteria provided by the Rytter. Each level of identification is correlated with specific information related to monitored structure. In fact, by increasing the level it is possible to obtain more information about the state of the health of the structures, to know if damage occurred on the structures, to quantify and localize the damage and to evaluate its impact on the monitored structure. Several authors discussed on the possibility to use the mode shape curvature to localize damage on structural elements, for example, by applying the curvature-based method to frequency response function instead of mode shape, and demonstrated the potential of this approach by considering real data. Damage detection approach based on dynamic monitoring of structural properties over time has received a considerable attention in recent scientific literature. In earthquake engineering field, the recourse to experimental research is necessary to understand the mechanical behaviour of the various structural and non-structural components. In this paper a new methodology to detect and localize a possible damage occurred on a framed structure after an earthquake is presented and discussed. The main outcomes retrieved from many numerical non linear dynamic models of reinforced concrete framed structures characterized by 3, 5 and 8 floors with different geometric configurations and designed for gravity loads only are here presented. In addition, the main results of experimental shaking table tests carried out on a steel framed model are also showed to confirm the effectiveness of the proposed procedure. Acknowledgements This study was partially funded by the Italian Civil Protection Department within the project DPC-RELUIS 2014 - RS4 ''Seismic observatory of structures and health monitoring''.

Aligned carbon nanotube based ultrasonic microtransducers for durability monitoring in civil engineering.

PubMed

Lebental, B; Chainais, P; Chenevier, P; Chevalier, N; Delevoye, E; Fabbri, J-M; Nicoletti, S; Renaux, P; Ghis, A

2011-09-30

Structural health monitoring of porous materials such as concrete is becoming a major component in our resource-limited economy, as it conditions durable exploitation of existing facilities. Durability in porous materials depends on nanoscale features which need to be monitored in situ with nanometric resolution. To address this problem, we put forward an approach based on the development of a new nanosensor, namely a capacitive micrometric ultrasonic transducer whose vibrating membrane is made of aligned single-walled carbon nanotubes (SWNT). Such sensors are meant to be embedded in large numbers within a porous material in order to provide information on its durability by monitoring in situ neighboring individual micropores. In the present paper, we report on the feasibility of the key building block of the proposed sensor: we have fabricated well-aligned, ultra-thin, dense SWNT membranes that show above-nanometer amplitudes of vibration over a large range of frequencies spanning from 100 kHz to 5 MHz.

Damage monitoring of aircraft structures made of composite materials using wavelet transforms

NASA Astrophysics Data System (ADS)

Molchanov, D.; Safin, A.; Luhyna, N.

2016-10-01

The present article is dedicated to the study of the acoustic properties of composite materials and the application of non-destructive testing methods to aircraft components. A mathematical model of a wavelet transformed signal is presented. The main acoustic (vibration) properties of different composite material structures were researched. Multiple vibration parameter dependencies on the noise reduction factor were derived. The main steps of a research procedure and new method algorithm are presented. The data obtained was compared with the data from a three dimensional laser-Doppler scanning vibrometer, to validate the results. The new technique was tested in the laboratory and on civil aircraft at a training airfield.

Public social monitoring reports and their effect on a policy programme aimed at addressing the social determinants of health to improve health equity in New Zealand.

PubMed

Pega, Frank; Valentine, Nicole B; Matheson, Don; Rasanathan, Kumanan

2014-01-01

The important role that monitoring plays in advancing global health is well established. However, the role of social monitoring as a tool for addressing social determinants of health (SDH) and health equity-focused policies remains under-researched. This paper assesses the extent and ways in which New Zealand's (NZ) Social Reports (SRs) supported a SDH- and health equity-oriented policy programme nationally over the 2000-2008 period by documenting the SRs' history and assessing its impact on policies across sectors in government and civil society. We conducted key-informant interviews with five senior policy-makers and an e-mail survey with 24 government and civil society representatives on SRs' history and policy impact. We identified common themes across these data and classified them accordingly to assess the intensity of the reports' use and their impact on SDH- and health equity-focused policies. Bibliometric analyses of government publications and media items were undertaken to empirically assess SRs' impact on government and civil society. SRs in NZ arose out of the role played by government as the "benevolent social welfare planner" and an understanding of the necessity of economic and social security for "progress". The SRs were linked to establishing a government-wide programme aimed at reducing inequalities. They have been used moderately to highly in central and local government and in civil society, both within and outside the health sector, but have neither entered public treasury and economic development departments nor the commercial sector. The SRs have not reached the more universal status of economic indicators. However, they have had some success at raising awareness of, and have stimulated isolated action on, SDH. The NZ case suggests that national-level social monitoring provides a valuable tool for raising awareness of SDH across government and civil society. A number of strategies could improve social reports' effectiveness in stimulating action on SDH. Copyright © 2013 Elsevier Ltd. All rights reserved.

Light weight, high-speed, and self-powered wireless fiber optic sensor (WiFOS) structural health monitor system for avionics and aerospace environments

NASA Astrophysics Data System (ADS)

Mendoza, Edgar A.; Kempen, Cornelia; Sun, Sunjian; Esterkin, Yan

2014-09-01

This paper describes recent progress towards the development of an innovative light weight, high-speed, and selfpowered wireless fiber optic sensor (WiFOS™) structural health monitor system suitable for the onboard and in-flight unattended detection, localization, and classification of load, fatigue, and structural damage in advanced composite materials commonly used in avionics and aerospace systems. The WiFOS™ system is based on ROI's advancements on monolithic photonic integrated circuit microchip technology, integrated with smart power management, on-board data processing, wireless data transmission optoelectronics, and self-power using energy harvesting tools such as solar, vibration, thermoelectric, and magneto-electric. The self-powered, wireless WiFOS™ system offers a versatile and powerful SHM tool to enhance the reliability and safety of avionics platforms, jet fighters, helicopters, commercial aircraft that use lightweight composite material structures, by providing comprehensive information about the structural integrity of the structure from a large number of locations. Immediate SHM applications are found in rotorcraft and aircraft, ships, submarines, and in next generation weapon systems, and in commercial oil and petrochemical, aerospace industries, civil structures, power utilities, portable medical devices, and biotechnology, homeland security and a wide spectrum of other applications.

Securing Equal Educational Opportunity: Report to the President and Secretary of Education, Fiscal Year 2016

ERIC Educational Resources Information Center

Office for Civil Rights, US Department of Education, 2016

2016-01-01

In FY 2016, the Office for Civil Rights (OCR) promoted equity and excellence in education through conducting investigations and monitoring schools under resolution agreements, promoting greater understanding of how OCR interprets and enforces civil rights laws through the release of policy guidance, providing technical assistance and outreach to…

40 CFR 63.10001 - Affirmative defense for exceedence of emission limit during malfunction.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the standards set forth in § 63.9991 you may assert an affirmative defense to a claim for civil... best monitoring methods and engineering judgment, the amount of excess emissions that were the result... of an affirmative defense to civil penalties for that malfunction. The owner or operator seeking to...

40 CFR 63.1551 - Affirmative defense for exceedance of emission limit during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... affirmative defense to a claim for civil penalties for exceedances of such standards that are caused by... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering... avail itself of an affirmative defense to civil penalties for that malfunction. The owner or operator...

40 CFR 63.1551 - Affirmative defense for exceedance of emission limit during malfunction.

Code of Federal Regulations, 2013 CFR

2013-07-01

... affirmative defense to a claim for civil penalties for exceedances of such standards that are caused by... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering... avail itself of an affirmative defense to civil penalties for that malfunction. The owner or operator...

40 CFR 63.10001 - Affirmative defense for exceedence of emission limit during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the standards set forth in § 63.9991 you may assert an affirmative defense to a claim for civil... best monitoring methods and engineering judgment, the amount of excess emissions that were the result... of an affirmative defense to civil penalties for that malfunction. The owner or operator seeking to...

Development of a real-time bridge structural monitoring and warning system: a case study in Thailand

NASA Astrophysics Data System (ADS)

Khemapech, I.; Sansrimahachai, W.; Toachoodee, M.

2017-04-01

Regarded as one of the physical aspects under societal and civil development and evolution, engineering structure is required to support growth of the nation. It also impacts life quality and safety of the civilian. Despite of its own weight (dead load) and live load, structural members are also significantly affected by disaster and environment. Proper inspection and detection are thus crucial both during regular and unsafe events. An Enhanced Structural Health Monitoring System Using Stream Processing and Artificial Neural Network Techniques (SPANNeT) has been developed and is described in this paper. SPANNeT applies wireless sensor network, real-time data stream processing and artificial neural network based upon the measured bending strains. Major contributions include an effective, accurate and energy-aware data communication and damage detection of the engineering structure. Strain thresholds have been defined according to computer simulation results and the AASHTO (American Association of State Highway and Transportation Officials) LRFD (Load and Resistance Factor Design) Bridge Design specifications for launching several warning levels. SPANNeT has been tested and evaluated by means of computer-based simulation and on-site levels. According to the measurements, the observed maximum values are 25 to 30 microstrains during normal operation. The given protocol provided at least 90% of data communication reliability. SPANNeT is capable of real-time data report, monitoring and warning efficiently conforming to the predefined thresholds which can be adjusted regarding user's requirements and structural engineering characteristics.

Civil engineering reference guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merritt, F.S.

1986-01-01

The civil engineering reference guide contains the following: Structural theory. Structural steel design. Concrete design and construction. Wood design and construction. Bridge engineering. Geotechnical engineering. Water engineering. Environmental engineering. Surveying.

Use of composite materials, health monitoring and self-healing concepts to refurbish our civil and military infrastructure.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roach, Dennis Patrick; Delong, Waylon Anthony; White, Scott

An unavoidable by-product of a metallic structure's use is the appearance of crack, corrosion, erosion and other flaws. Economic barriers to the replacement of these structures have created an aging civil and military infrastructure and placed even greater demands on efficient and safe repair and inspection methods. As a result of Homeland Security issues and these aging infrastructure concerns, increased attention has been focused on the rapid repair and preemptive reinforcement of structures such as buildings and bridges. This Laboratory Directed Research and Development (LDRD) program established the viability of using bonded composite patches to repair metallic structures. High modulusmore » fiber-reinforced polymer (FRP) material may be used in lieu of mechanically fastened metallic patches or welds to reinforce or repair damaged structures. Their use produces a wide array of engineering and economic advantages. Current techniques for strengthening steel structures have several drawbacks including requiring heavy equipment for installation, poor fatigue performance, and the need for ongoing maintenance due to continued corrosion attack or crack growth. The use of bonded composite doublers has the potential to correct the difficulties associated with current repair techniques and the ability to be applied where there are currently no rehabilitation options. Applications include such diverse structures as: buildings, bridges, railroad cars, trucks and other heavy machinery, steel power and communication towers, pipelines, factories, mining equipment, ships, tanks and other military vehicles. This LDRD also proved the concept of a living infrastructure by developing custom sensors and self-healing chemistry and linking this technology with the application of advanced composite materials. Structural Health Monitoring (SHM) systems and mountable, miniature sensors were designed to continuously or periodically assess structural integrity. Such systems are able to detect incipient damage before catastrophic failure occurs. The ease of monitoring an entire network of distributed sensors means that structural health assessments can occur more often, allowing operators to be even more vigilant with respect to flaw onset. In addition, the realization of smart structures, through the use of in-situ sensors, allows condition-based maintenance to be substituted for conventional time-based maintenance practices. The sensitivity and reliability of a series of sensor systems was quantified in laboratory and real-world environments. Finally, self healing methods for composite materials were evolved--using resin modules that are released in response to the onset of delaminations--so that these components can provide a living infrastructure with minimal need for human intervention. This program consisted of four related research elements: (1) design, installation, and performance assessment of composite repairs, (2) in-situ sensors for real-time health monitoring, (3) self healing of in-service damage in a repair, and (4) numerical modeling. Deployment of FRP materials and bonded joints requires proper design, suitable surface preparation methods, and adequate surveillance to ensure structural integrity. By encompassing all 'cradle-to-grave' tasks --including design, analysis, installation, durability, flaw containment, and inspection--this program is designed to firmly establish the capabilities of composite doubler repairs and introduce technology to incorporate self-monitoring and self-healing (living structures) methodologies. A proof-of-concept repair was completed on a steel highway bridge in order to demonstrate the potential of composite doubler technology for critical infrastructure use.« less

Application of a moment tensor inversion code developed for mining-induced seismicity to fracture monitoring of civil engineering materials

NASA Astrophysics Data System (ADS)

Linzer, Lindsay; Mhamdi, Lassaad; Schumacher, Thomas

2015-01-01

A moment tensor inversion (MTI) code originally developed to compute source mechanisms from mining-induced seismicity data is now being used in the laboratory in a civil engineering research environment. Quantitative seismology methods designed for geological environments are being tested with the aim of developing techniques to assess and monitor fracture processes in structural concrete members such as bridge girders. In this paper, we highlight aspects of the MTI_Toolbox programme that make it applicable to performing inversions on acoustic emission (AE) data recorded by networks of uniaxial sensors. The influence of the configuration of a seismic network on the conditioning of the least-squares system and subsequent moment tensor results for a real, 3-D network are compared to a hypothetical 2-D version of the same network. This comparative analysis is undertaken for different cases: for networks consisting entirely of triaxial or uniaxial sensors; for both P and S-waves, and for P-waves only. The aim is to guide the optimal design of sensor configurations where only uniaxial sensors can be installed. Finally, the findings of recent laboratory experiments where the MTI_Toolbox has been applied to a concrete beam test are presented and discussed.

Design and Implementation of a New System for Large Bridge Monitoring—GeoSHM

PubMed Central

Xie, Yilin; Ince, Sean; Ye, Jun; Bhatia, Paul

2018-01-01

Structural Health Monitoring (SHM) is a relatively new branch of civil engineering that focuses on assessing the health status of infrastructure, such as long-span bridges. Using a broad range of in-situ monitoring instruments, the purpose of the SHM is to help engineers understand the behaviour of structures, ensuring their structural integrity and the safety of the public. Under the Integrated Applications Promotion (IAP) scheme of the European Space Agency (ESA), a feasibility study (FS) project that used the Global Navigation Satellite Systems (GNSS) and Earth Observation (EO) for Structural Health Monitoring of Long-span Bridges (GeoSHM) was initiated in 2013. The GeoSHM FS Project was led by University of Nottingham and the Forth Road Bridge (Scotland, UK), which is a 2.5 km long suspension bridge across the Firth of Forth connecting Edinburgh and the Northern part of Scotland, was selected as the test structure for the GeoSHM FS project. Initial results have shown the significant potential of the GNSS and EO technologies. With these successes, the FS project was further extended to the demonstration stage, which is called the GeoSHM Demo project where two other long-span bridges in China were included as test structures. Led by UbiPOS UK Ltd. (Nottingham, UK), a Nottingham Hi-tech company, this stage focuses on addressing limitations identified during the feasibility study and developing an innovative data strategy to process, store, and interpret monitoring data. This paper will present an overview of the motivation and challenges of the GeoSHM Demo Project, a description of the software and hardware architecture and a discussion of some primary results that were obtained in the last three years. PMID:29510534

NDE Conference on Civil Engineering : a joint conference of the 7th Structural Materials Technology Conference (SMT) and the 6th International Symposium on Nondestructive Testing in Civil Engineering (NDT-CE)

DOT National Transportation Integrated Search

2007-01-01

The 2006 NDE conference on Civil Engineering was held in St. Louis, MO on August 14 18, 2006. The conference combined the 7th Structural Materials Technology Conference (SMT) along with the 6th International Symposium on Nondestructive Testing in...

History and challenges of Brazilian social movements for the achievement of the right to adequate food.

PubMed

da Silva, Ana Carolina Feldenheimer; Recine, Elisabetta; Johns, Paula; Gomes, Fabio da Silva; Ferraz, Mariana de Araújo; Faerstein, Eduardo

2018-03-01

The historical struggles that Brazil faced to overcome malnutrition coincided with the empowerment of civil society and social movements which played a crucial role in the affirmation of health and food as social rights. After two decades under military dictatorship, Brazil went through a redemocratization process in the 1980s when activism emerged to demand spaces to participate in policy-making regarding the social agenda, including food and nutrition security (FNS). From 1988 onward institutional structures were established: the National Council of FNS (CONSEA) convenes government and civil society sectors to develop and monitor the implementation of policies, systems and actions. Social participation has been at the heart of structural changes achieved since then. Nevertheless, the country faces multiple challenges regarding FNS such as the double burden of disease, increasing use of pesticides and genetically modified seeds, weak regulation of ultra-processed products, and marketing practices that affect the environment, population health, and food sovereignty. This article aims at examining the development of the participatory political system and the role played by Brazilian social movements in the country's policies on FNS, in addition to outlining challenges faced by those policies.

A novel camera localization system for extending three-dimensional digital image correlation

NASA Astrophysics Data System (ADS)

Sabato, Alessandro; Reddy, Narasimha; Khan, Sameer; Niezrecki, Christopher

2018-03-01

The monitoring of civil, mechanical, and aerospace structures is important especially as these systems approach or surpass their design life. Often, Structural Health Monitoring (SHM) relies on sensing techniques for condition assessment. Advancements achieved in camera technology and optical sensors have made three-dimensional (3D) Digital Image Correlation (DIC) a valid technique for extracting structural deformations and geometry profiles. Prior to making stereophotogrammetry measurements, a calibration has to be performed to obtain the vision systems' extrinsic and intrinsic parameters. It means that the position of the cameras relative to each other (i.e. separation distance, cameras angle, etc.) must be determined. Typically, cameras are placed on a rigid bar to prevent any relative motion between the cameras. This constraint limits the utility of the 3D-DIC technique, especially as it is applied to monitor large-sized structures and from various fields of view. In this preliminary study, the design of a multi-sensor system is proposed to extend 3D-DIC's capability and allow for easier calibration and measurement. The suggested system relies on a MEMS-based Inertial Measurement Unit (IMU) and a 77 GHz radar sensor for measuring the orientation and relative distance of the stereo cameras. The feasibility of the proposed combined IMU-radar system is evaluated through laboratory tests, demonstrating its ability in determining the cameras position in space for performing accurate 3D-DIC calibration and measurements.

Detection of structural damage in multiwire cables by monitoring the entropy evolution of wavelet coefficients

NASA Astrophysics Data System (ADS)

Ibáñez, Flor; Baltazar, Arturo; Mijarez, Rito; Aranda, Jorge

2015-03-01

Multiwire cables are widely used in important civil structures. Since they are exposed to several dynamic and static loads, their structural health can be compromised. The cables can also be submitted to mechanical contact, tension and energy propagation in addition to changes in size and material within their wires. Due to the critical role played by multiwire cables, it is necessary to develop a non-destructive health monitoring method to maintain their structure and proper performance. Ultrasonic inspection using guided waves is a promising non-destructive damage monitoring technique for rods, single wires and multiwire cables. The propagated guided waves are composed by an infinite number of vibrational modes making their analysis difficult. In this work, an entropy-based method to identify small changes in non-stationary signals is proposed. A system to capture and post-process acoustic signals is implemented. The Discrete Wavelet Transform (DWT) is computed in order to obtain the reconstructed wavelet coefficients of the signals and to analyze the energy at different scales. The feasibility of using the concept of entropy evolution of non-stationary signals to detect damage in multiwire cables is evaluated. The results show that there is a high correlation between the entropy value and damage level of the cable. The proposed method has low sensitivity to noise and reduces the computational complexity found in a typical time-frequency analysis.

In situ monitoring of the integrity of bonded repair patches on aircraft and civil infrastructures

NASA Astrophysics Data System (ADS)

Kumar, Amrita; Roach, Dennis; Beard, Shawn; Qing, Xinlin; Hannum, Robert

2006-03-01

Monitoring the continued health of aircraft subsystems and identifying problems before they affect airworthiness has been a long-term goal of the aviation industry. Because in-service conditions and failure modes experienced by structures are generally complex and unknown, conservative calendar-based or usage-based scheduled maintenance practices are overly time-consuming, labor-intensive and expensive. Metal structures such as helicopters and other transportation systems are likely to develop fatigue cracks under cyclic loads and corrosive service environments. Early detection of cracks is a key element to prevent catastrophic failure and prolong structural life. Furthermore, as structures age, maintenance service frequency and costs increase while performance and availability decrease. Current non-destructive inspection (NDI) techniques that can potentially be used for this purpose typically involve complex, time-intensive procedures, which are labor-intensive and expensive. Most techniques require access to the damaged area on at least one side, and sometimes on both sides. This can be very difficult for monitoring of certain inaccessible regions. In those cases, inspection may require removal of access panels or even structural disassembly. Once access has been obtained, automated inspection techniques likely will not be practical due to the bulk of the required equipment. Results obtained from these techniques may also be sensitive to the sweep speed, tool orientation, and downward pressure. This can be especially problematic for hand-held inspection tools where none of these parameters is mechanically controlled. As a result, data can vary drastically from one inspection to the next, from one technician to the next, and even from one sweep to the next. Structural health monitoring (SHM) offers the promise of a paradigm shift from schedule-driven maintenance to condition-based maintenance (CBM) of assets. Sensors embedded permanently in aircraft safety critical structures that can monitor damage can provide for improved reliability and streamlining of aircraft maintenance. Early detection of damage such as fatigue crack initiation can improve personnel safety and prolong service life. This paper presents the testing of an acousto-ultrasonic piezoelectric sensor based structural health monitoring system for real-time monitoring of fatigue cracks and disbonds in bonded repairs. The system utilizes a network of distributed miniature piezoelectric sensors/actuators embedded on a thin dielectric carrier film, to query, monitor and evaluate the condition of a structure. The sensor layers are extremely flexible and can be integrated with any type of metal or composite structure. Diagnostic signals obtained from a structure during structural monitoring are processed by a portable diagnostic unit. With appropriate diagnostic software, the signals can be analyzed to ascertain the integrity of the structure being monitored. Details on the system, its integration and examples of detection of fatigue crack and disbond growth and quantification for bonded repairs will be presented here.

An on-line monitoring system for navigation equipment

NASA Astrophysics Data System (ADS)

Wang, Bo; Yang, Ping; Liu, Jing; Yang, Zhengbo; Liang, Fei

2017-10-01

Civil air navigation equipment is the most important infrastructure of Civil Aviation, which is closely related to flight safety. In addition to regular flight inspection, navigation equipment's patrol measuring, maintenance measuring, running measuring under special weather conditions are the important means of ensuring aviation flight safety. According to the safety maintenance requirements of Civil Aviation Air Traffic Control navigation equipment, this paper developed one on-line monitoring system with independent intellectual property rights for navigation equipment, the system breakthroughs the key technologies of measuring navigation equipment on-line including Instrument Landing System (ILS) and VHF Omni-directional Range (VOR), which also meets the requirements of navigation equipment ground measurement set by the ICAO DOC 8071, it provides technical means of the ground on-line measurement for navigation equipment, improves the safety of navigation equipment operation, and reduces the impact of measuring navigation equipment on airport operation.

Image restoration for civil engineering structure monitoring using imaging system embedded on UAV

NASA Astrophysics Data System (ADS)

Vozel, Benoit; Dumoulin, Jean; Chehdi, Kacem

2013-04-01

Nowadays, civil engineering structures are periodically surveyed by qualified technicians (i.e. alpinist) operating visual inspection using heavy mechanical pods. This method is far to be safe, not only for civil engineering structures monitoring staff, but also for users. Due to the unceasing traffic increase, making diversions or closing lanes on bridge becomes more and more difficult. New inspection methods have to be found. One of the most promising technique is to develop inspection method using images acquired by a dedicated monitoring system operating around the civil engineering structures, without disturbing the traffic. In that context, the use of images acquired with an UAV, which fly around the structures is of particular interest. The UAV can be equipped with different vision system (digital camera, infrared sensor, video, etc.). Nonetheless, detection of small distresses on images (like cracks of 1 mm or less) depends on image quality, which is sensitive to internal parameters of the UAV (vibration modes, video exposure times, etc.) and to external parameters (turbulence, bad illumination of the scene, etc.). Though progresses were made at UAV level and at sensor level (i.e. optics), image deterioration is still an open problem. These deteriorations are mainly represented by motion blur that can be coupled with out-of-focus blur and observation noise on acquired images. In practice, deteriorations are unknown if no a priori information is available or dedicated additional instrumentation is set-up at UAV level. Image restoration processing is therefore required. This is a difficult problem [1-3] which has been intensively studied over last decades [4-12]. Image restoration can be addressed by following a blind approach or a myopic one. In both cases, it includes two processing steps that can be implemented in sequential or alternate mode. The first step carries out the identification of the blur impulse response and the second one makes use of this estimated blur kernel for performing the deconvolution of the acquired image. In the present work, different regularization methods, mainly based on the pseudo norm aforementioned Total Variation, are studied and analysed. The key point of their respective implementation, their properties and limits are investigated in this particular applicative context. References [1] J. Hadamard. Lectures on Cauchy's problem in linear partial differential equations. Yale University Press, 1923. [2] A. N. Tihonov. On the resolution of incorrectly posed problems and regularisation method (in Russian). Doklady A. N.SSSR, 151(3), 1963. [3] C. R. Vogel. Computational Methods for inverse problems, SIAM, 2002. [4] A. K. Katsaggelos, J. Biemond, R.W. Schafer, and R. M. Mersereau, "A regularized iterative image restoration algorithm," IEEE Transactions on Signal Processing, vol.39, no. 4, pp. 914-929, 1991. [5] J. Biemond, R. L. Lagendijk, and R. M. Mersereau, "Iterative methods for image deblurring," Proceedings of the IEEE, vol. 78, no. 5, pp. 856-883, 1990. [6] D. Kundur and D. Hatzinakos, "Blind image deconvolution," IEEE Signal Processing Magazine, vol. 13, no. 3, pp. 43-64, 1996. [7] Y. L. You and M. Kaveh, "A regularization approach to joint blur identification and image restoration," IEEE Transactions on Image Processing, vol. 5, no. 3, pp. 416-428, 1996. [8] T. F. Chan and C. K. Wong, "Total variation blind deconvolution," IEEE Transactions on Image Processing, vol. 7, no. 3, pp. 370-375, 1998. [9] S. Chardon, B. Vozel, and K. Chehdi. Parametric Blur Estimation Using the GCV Criterion and a Smoothness Constraint on the Image. Multidimensional Systems and Signal Processing Journal, Kluwer Ed., 10:395-414, 1999 [10] B. Vozel, K. Chehdi, and J. Dumoulin. Myopic image restoration for civil structures inspection using UAV (in French). In GRETSI, 2005. [11] L. Bar, N. Sochen, and N. Kiryati. Semi-blind image restoration via Mumford-Shah regularization. IEEE Transactions on Image Processing, 15(2), 2006. [12] J. H. Money and S. H. Kang, "Total variation minimizing blind deconvolution with shock filter reference," Image and Vision Computing, vol. 26, no. 2, pp. 302-314, 2008.

Triboluminesence multifunctional cementitious composites with in situ damage sensing capability

NASA Astrophysics Data System (ADS)

Olawale, David O.; Dickens, Tarik; Uddin, Mohammed J.; Okoli, Okenwa O.

2012-04-01

Structural health monitoring of civil infrastructure systems like concrete bridges and dams has become critical because of the aging and overloading of these CIS. Most of the available SHM methods are not in-situ and can be very expensive. The triboluminescence multifunctional cementitious composites (TMCC) have in-built crack detection mechanism that can enable bridge engineers to monitor and detect abnormal crack formation in concrete structures so that timely corrective action can be taken to prevent costly or catastrophic failures. This article reports the fabrication process and test result of the flexural characterization of the TMCC. Accelerated durability test indicated that the 0.5 ZnS:Mn/Epoxy weight fraction ITOF sensor configuration to be more desirable in terms of durability. The alkaline environment at the highest temperature investigated (45 °C) resulted in significant reduction in the mean glass transition and storage moduli of the tested ITOF thin films. Further work is ongoing to correlate the TL response of the TMCC with damage, particularly crack opening.

Multimodal inspection in power engineering and building industries: new challenges and solutions

NASA Astrophysics Data System (ADS)

Kujawińska, Małgorzata; Malesa, Marcin; Malowany, Krzysztof

2013-09-01

Recently the demand and number of applications of full-field, optical measurement methods based on noncoherent light sources increased significantly. They include traditional image processing, thermovision, digital image correlation (DIC) and structured light methods. However, there are still numerous challenges connected with implementation of these methods to in-situ, long-term monitoring in industrial, civil engineering and cultural heritage applications, multimodal measurements of a variety of object features or simply adopting instruments to work in hard environmental conditions. In this paper we focus on 3D DIC method and present its enhancements concerning software modifications (new visualization methods and a method for automatic merging of data distributed in time) and hardware improvements. The modified 3D DIC system combined with infrared camera system is applied in many interesting cases: measurements of boiler drum during annealing and of pipelines in heat power stations and monitoring of different building steel struts at construction site and validation of numerical models of large building structures constructed of graded metal plate arches.

The Role of Civil Society Organizations in Monitoring the Global AIDS Response.

PubMed

Smith, Julia; Mallouris, Christoforos; Lee, Kelley; Alfvén, Tobias

2017-07-01

Civil society organizations (CSOs) are recognized as playing an exceptional role in the global AIDS response. However, there is little detailed research to date on how they contribute to specific governance functions. This article uses Haas' framework on global governance functions to map CSO's participation in the monitoring of global commitments to the AIDS response by institutions and states. Drawing on key informant interviews and primary documents, it focuses specifically on CSO participation in Global AIDS Response Progress Reporting and in Global Fund to Fight AIDS, Tuberculosis and Malaria processes. It argues that the AIDS response is unique within global health governance, in that CSOs fulfill both formal and informal monitoring functions, and considers the strengths and weaknesses of these contributions. It concludes that future global health governance arrangements should include provisions and resources for monitoring by CSOs because their participation creates more inclusive global health governance and contributes to strengthening commitments to human rights.

40 CFR 60.5181 - How do I establish an affirmative defense for exceedance of an emission limit or standard during...

Code of Federal Regulations, 2013 CFR

2013-07-01

....5165, you may assert an affirmative defense to a claim for civil penalties for exceedances of emission... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering... an affirmative defense to civil penalties for that malfunction. The owner or operator seeking to...

40 CFR 60.5181 - How do I establish an affirmative defense for exceedance of an emission limit or standard during...

Code of Federal Regulations, 2014 CFR

2014-07-01

....5165, you may assert an affirmative defense to a claim for civil penalties for exceedances of emission... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering... an affirmative defense to civil penalties for that malfunction. The owner or operator seeking to...

40 CFR 63.11226 - How can I assert an affirmative defense if I exceed an emission limit during a malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... you may assert an affirmative defense to a claim for civil penalties for exceedances of numerical... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering... avail itself of an affirmative defense to civil penalties for that malfunction. The owner or operator...

49 CFR Appendix G to Part 227 - Schedule of Civil Penalties

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Schedule of Civil Penalties G Appendix G to Part... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OCCUPATIONAL NOISE EXPOSURE Pt. 227, App. G Appendix G to Part 227... omitted 2,500 5,000 (f) Failure to provide opportunity to observe monitoring 2,000 4,000 (g) Reporting of...

49 CFR Appendix G to Part 227 - Schedule of Civil Penalties

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Schedule of Civil Penalties G Appendix G to Part... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OCCUPATIONAL NOISE EXPOSURE Pt. 227, App. G Appendix G to Part 227... omitted 2,500 5,000 (f) Failure to provide opportunity to observe monitoring 2,000 4,000 (g) Reporting of...

49 CFR Appendix G to Part 227 - Schedule of Civil Penalties

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Schedule of Civil Penalties G Appendix G to Part... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OCCUPATIONAL NOISE EXPOSURE Pt. 227, App. G Appendix G to Part 227... omitted 2,500 5,000 (f) Failure to provide opportunity to observe monitoring 2,000 4,000 (g) Reporting of...

75 FR 16819 - Notice of Proposed Information Collection for Public Comment Civil Rights Front End and Limited...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-02

... Information Collection for Public Comment Civil Rights Front End and Limited Monitoring Review AGENCY: Office... Office of Management and Budget (OMB) for review, as required by the Paperwork Reduction Act. The...-free Federal Information Relay Service at 800-877-8339. (Other than the HUD USER information line and...

Delivering Justice: Report to the President and Secretary of Education, Fiscal Year 2015

ERIC Educational Resources Information Center

Office for Civil Rights, US Department of Education, 2015

2015-01-01

For decades, the Office for Civil Rights (OCR) has enforced civil rights in our nation's preschool through 12th grade (P-12) and post-secondary schools, which now serve almost 80 million students annually. In Fiscal Year 2015, the OCR promoted excellence in education through conducting investigations and monitoring schools under resolution…

Wireless structural monitoring for homeland security applications

NASA Astrophysics Data System (ADS)

Kiremidjian, Garo K.; Kiremidjian, Anne S.; Lynch, Jerome P.

2004-07-01

This paper addresses the development of a robust, low-cost, low power, and high performance autonomous wireless monitoring system for civil assets such as large facilities, new construction, bridges, dams, commercial buildings, etc. The role of the system is to identify the onset, development, location and severity of structural vulnerability and damage. The proposed system represents an enabling infrastructure for addressing structural vulnerabilities specifically associated with homeland security. The system concept is based on dense networks of "intelligent" wireless sensing units. The fundamental properties of a wireless sensing unit include: (a) interfaces to multiple sensors for measuring structural and environmental data (such as acceleration, displacements, pressure, strain, material degradation, temperature, gas agents, biological agents, humidity, corrosion, etc.); (b) processing of sensor data with embedded algorithms for assessing damage and environmental conditions; (c) peer-to-peer wireless communications for information exchange among units(thus enabling joint "intelligent" processing coordination) and storage of data and processed information in servers for information fusion; (d) ultra low power operation; (e) cost-effectiveness and compact size through the use of low-cost small-size off-the-shelf components. An integral component of the overall system concept is a decision support environment for interpretation and dissemination of information to various decision makers.

Photocopy of plan (in collection of U.S. Coast Guard Civil ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of plan (in collection of U.S. Coast Guard Civil Engineering Unit Providence, Warwick, RI), U.S. Coast Guard Civil Engineering, third district, Sandy Hook L/B Station showing boat basin plan, circa 1945 Detail of western docking structure - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

The new emergency structure of the Istituto Nazionale di Geofisica e Vulcanologia during the L’Aquila 2009 seismic sequence: the contribution of the COES (Seismological Emergency Operation Center - Centro Operativo Emergenza Sismica)

NASA Astrophysics Data System (ADS)

Moretti, M.; Govoni, A.; Nostro, C.; La Longa, F.; Crescimbene, M.; Pignone, M.; Selvaggi, G.; Working Group, C.

2009-12-01

The Centro Nazionale Terremoti (CNT - National Earthquake Center), departement of Istituto Nazionale di Geofisica e Vulcanologia (INGV), has designed and setup a rapid response emergency structure to face the occurrence of strong earthquakes. This structure is composed by a real time satellite telemetered temporary seismic network (see Abruzzese et al., 2009 Fall AGU) used to improve the hypocentral locations of the INGV National Seismic Network, a stand alone temporary seismic network whose goal is primarily the high dynamic/high resolution data acquisition in the epicentral area and a mobile operational center, the COES (Centro Operativo Emergenza Sismica, Seismological Emergency Operational Center). The COES structure is a sort of mobile office equipped with satellite internet communication that can be rapidly installed in the disaster area to support all the INGV staff operative needs and to cooperate with the Civil Protection department (DPC) aggregating all the scientific information available on the seismic sequence and providing updated information to Civil Protection for the decision making stage during the emergency. The structure is equipped with a heavy load trolley that carries a 6x6 inflatable tent, a satellite router, an UPS, computers, monitors and furniture. The facility can be installed in a couple of hours in the epicentral area and provides a full featured office with dedicated internet connection and VPN access to the INGV data management center in Rome. Just after the April 6 2009 Mw 6.3 earthquake in L’Aquila (Central Italy) the COES has been installed upon request of the Italian Civil Protection (DPC) in the DICOMAC (Directorate of Command and Control - which is the central structure of the DPC that coordinates the emergency activities in the areas affected by the earthquake) located in the Guardia di Finanza headquarters in Coppito nearby L'Aquila (the same location that hosted the G8 meeting). The COES produces real time reports on the seismic sequence evolution constituted by a detailed sequence map, histograms showing the evolution of the magnitude and the number of earthquakes in time and a daily event list. Moreover, it is possible to see the real time hypocentral locations using “SISMAP” (Doumaz et al., 2008), the same tool used in the Seismic Monitoring Center in Rome. During the emergency the COES has been also a reference information point for all people involved in the crisis management and has provided also psychological support to the rescuers and to the earthquake affected population. This education and outreach activity has proved to be extremely effective. References Abruzzese L. et al., AGU Fall Meeting 2009. Doumaz F. et al., Geomedia, speciale geologia, pp. 10-13, 2008.

49 CFR Appendix G to Part 227 - Schedule of Civil Penalties

Code of Federal Regulations, 2010 CFR

2010-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OCCUPATIONAL NOISE EXPOSURE Pt. 227, App. G Appendix G to Part 227... Requirements 227.103Noise monitoring program: (a) Failure to develop and/or implement a noise monitoring... levels and/or make noise measurements as required 2,500 5,000 (d) Failure to repeat noise monitoring...

Citizen Sensors for SHM: Use of Accelerometer Data from Smartphones

PubMed Central

Feng, Maria; Fukuda, Yoshio; Mizuta, Masato; Ozer, Ekin

2015-01-01

Ubiquitous smartphones have created a significant opportunity to form a low-cost wireless Citizen Sensor network and produce big data for monitoring structural integrity and safety under operational and extreme loads. Such data are particularly useful for rapid assessment of structural damage in a large urban setting after a major event such as an earthquake. This study explores the utilization of smartphone accelerometers for measuring structural vibration, from which structural health and post-event damage can be diagnosed. Widely available smartphones are tested under sinusoidal wave excitations with frequencies in the range relevant to civil engineering structures. Large-scale seismic shaking table tests, observing input ground motion and response of a structural model, are carried out to evaluate the accuracy of smartphone accelerometers under operational, white-noise and earthquake excitations of different intensity. Finally, the smartphone accelerometers are tested on a dynamically loaded bridge. The extensive experiments show satisfactory agreements between the reference and smartphone sensor measurements in both time and frequency domains, demonstrating the capability of the smartphone sensors to measure structural responses ranging from low-amplitude ambient vibration to high-amplitude seismic response. Encouraged by the results of this study, the authors are developing a citizen-engaging and data-analytics crowdsourcing platform towards a smartphone-based Citizen Sensor network for structural health monitoring and post-event damage assessment applications. PMID:25643056

A Wireless Fatigue Monitoring System Utilizing a Bio-Inspired Tree Ring Data Tracking Technique

PubMed Central

Bai, Shi; Li, Xuan; Xie, Zhaohui; Zhou, Zhi; Ou, Jinping

2014-01-01

Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is proposed. The general framework, methodology, and verification of this intelligent system are discussed in details. The rain-flow counting (RFC) method is adopted as the core algorithm which quantifies fatigue damages, and Digital Signal Processing (DSP) is introduced as the core module for data collection and analysis. Laboratory test results based on strain gauges and polyvinylidene fluoride (PVDF) sensors have shown that the developed intelligent system can provide a reliable quick feedback and early warning of fatigue failure. With the merits of low cost, high accuracy and great reliability, the developed wireless fatigue sensing system can be further applied to mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, etc. PMID:24603635

FOREWORD: Cultural heritage and civil engineering Cultural heritage and civil engineering

NASA Astrophysics Data System (ADS)

Masini, Nicola; Soldovieri, Francesco; Alvarez de Buergo, Monica; Dumoulin, Jean

2012-08-01

This special issue of Journal of Geophysics and Engineering offers a diverse panorama of approaches and technologies that aim to characterize and analyse the state of conservation and health of cultural heritage and civil infrastructure. In particular, it provides a significant overview not only of the effectiveness but also of the limitations of single diagnostic techniques, which can be overcome through the integration of different methods and technologies and/or the use of robust and novel data processing techniques. The choice of diagnostic strategy depends on the material (concrete, masonry), the spatial characteristics of the objects or sites, the value of the objects to be investigated (cultural or not), the aim of the investigation (knowledge, conservation, restoration) and the issues to be addressed (monitoring, decay assessment, etc). The paper by Fornaro et al reports an important technological advance in the field of slow deformation monitoring of civil infrastructure by means of differential interferometric synthetic aperture radar (SAR) from satellite platforms. The paper shows how the joint exploitation of the last generation of X-band SAR sensors, such as TerraSAR-X, and novel tomographic approaches makes possible advanced multi-dimensional imaging of real structures such as the Las Vegas Monorail. Within the same SAR-based applications, Tapete et al tested the capability of persistent scatterer interferometry (PSI) techniques in the preventative diagnosis of deformation threatening the structural stability of archaeological monuments and buried structures in the Roman Forum, Palatino Hill and Oppio Hill in the centre of Rome. A PSInSAR processing approach, based on the use of the SqueeSAR algorithm, has been shown to be highly suitable for retrieving not only information about displacements of the archaeological remains, but also evidence of criticalities affecting partially or totally buried structures, such as those discovered at Nero's Golden House. Lasaponara et al, by means of integrating passive and active remotely sensed data, detect traces of past human activity on an Etruscan site in Northern Lazio, Italy. In particular, the use of different sensors (laser of LIDAR, infrared and near-infrared cameras, multispectral satellite data) allows for different types of surface cover, archaeological marks (micro-relief, crop marks, etc) and expected spatial/spectral feature patterns related to past human activities (urban necropoleis, palaeorivers, etc). Deroin et al present the results of a geoarchaeological project dealing with the study of mineral resources and metal production in the Andean plateau of southern Bolivia from the 10th to the 18th century. A field survey and a multisource remote sensing approach, from declassified satellite images taken in the 1960s to Lansdsat TM, and from ALOS-AVNIR-2 to very high resolution Geo-Eye data, has allowed the mapping of geological features and archaeological remains. The paper by Stabile et al is concerned with the very interesting and unique exploitation of 'non-conventional' techniques, such as the use of ground-based interferometric radar and high-frequency infrared cameras as non-remote-sensing tools, to obtain information about the dynamical behavior of real structures like the Sihlhochstrasse Bridge in Zurich (one of the largest bridges in Switzerland). The feasibility of these techniques is also testified by cross validation of monitoring results, which are in a good agreement. Minardo et al present a very promising technique based on a novel optic fiber sensor for the distributed monitoring of strain and temperature over long ranges. In particular, the sensor is particularly suitable for civil engineering and cultural heritage monitoring, as shown by a very interesting field application assessing the strain deformation of the Basento Bridge in Potenza, southern Italy, an architectural masterpiece of the 20th century designed by Musmeci. Grützner et al combine archaeology and geoarchaeology with remote sensing, including aerial images collected by a drone equipped with a high-resolution range-finder camera, and geophysical tools (ground penetrating radar, SQUID magnetometry, geoelectric) to obtain a comprehensive picture of the timing, archaeological meaning and environmental history of archaeological remains in the Orkhon Valley in Central Mongolia. Leucci et al evaluate the practical application of attenuation-based GPR attribute analysis methods in providing indirect information on moisture content, which is one of the main factors contributing to the decay of historical monuments. The results obtained confirm the presence of a relationship between soil hydraulic properties and amplitudes in the radargram. The papers by Catapano et al describe the effectiveness of the joint use of ground penetrating radar and advanced data processing based on microwave tomography as a solution to real problems in the field of cultural heritage and civil engineering. In particular, the use of an integrated strategy proved very helpful in driving excavations at an important survey at the Domus Centauro in Pompeii. The other successful case was concerned with the monitoring of the inside of a concrete beam affected by direct impacts, part of the Montagnole experiment within the ISTIMES project. The Montagnole experiment is concerned with the exploitation and performance of a large variety of electromagnetic sensing techniques for the non-invasive monitoring of the damage to a one-scale structure, such as a concrete beam, from controlled direct impacts. The surface properties of any material need to be modified to adapt to new conditions. As Vazquez-Calvo et al show, the measurement of surface roughness is a reliable test of the suitability of stone cleaning methods; this is a non-destructive technique, portable and easy to use, that can help us—together with other techniques such as polarizing optical microscopy, scanning electron microscopy and colour analysis—to assess the efficacy and the appropriateness or aggressiveness of any stone cleaning method. Tracking raw material back to its extraction source is a crucial step for archaeologists when trying to infer migration patterns and trade contacts in (pre-)history. The characterization of such material is therefore necessary. With this aim, Veldeman et al have analysed the hypersiliceous rocks of Belgium used in (pre-)history by using optical polarizing, optical cold cathode-luminescence and scanning-electron microscopy combined with energy-dispersive x-ray spectrometry and back-scatter electron imaging.

Intelligent Structural Health Management of Civil Infrastructure

DOT National Transportation Integrated Search

2012-10-19

The collapse of the I-35W Mississippi River Bridge in Minneapolis has spawned a growing interest in the : development of reliable techniques for evaluating the structural integrity of civil infrastructure. Current inspection : techniques tailored to ...

Use of the total station for load testing of retrofitted bridges with limited access

NASA Astrophysics Data System (ADS)

Merkle, Wesley J.; Myers, John J.

2004-07-01

As new technologies are increasingly applied to civil infrastructure, the need for structural monitoring systems becomes more critical. Serviceability, or deflection, is very important in monitoring the health of not only a structural system, but also in analyzing the affects of a new technology applied in the field. Traditionally, Linear Variable Displacement Transducers (LVDT"s) are used to measure deflection in many filed load tests. In the field, access can easily become an issue with this instrumentation system that is truly designed for laboratory use. LVDT instrumentation for load testing typically requires several labor intensive hours to prepare for a load test in the field; the system is accompanied by wiring and expensive electronics that may not only become a safety issue but is also very sensitive to the elements. Set up is especially difficult, if not impossible, on tall bridge spans and bridge spans over water. A recent research project required serviceability monitoring through a series of load tests for several retrofitted bridges in Missouri. For these tests, surveying equipment was employed in attempt to make serviceability measurement more practicable. Until recently, surveying equipment would not have produced the accuracy required for structural monitoring use; however, manufacturers of this equipment have developed new technologies to increase the accuracy of the instrumentation. The major component used, the total station, can measure deflection accurate to 0.2 millimeters (0.0079 in.). This monitoring system is much easier to set up and use, reducing labor and time requirements. The system has almost no site restrictions. This paper will compare and contrast the total station to traditional load testing monitoring equipment (LVDT).

Seismic Analysis of Intake Towers

DTIC Science & Technology

1982-10-01

Experiment Station (WES) under the sponsorship of the Directorate of Civil Works of the Office, Chief of Engineers, U. S. Army. The work was funded under...the structural capacity of the intake S,-tower are contained in Engineer Technical Letter (ETL) 1110-2-265 " Civil Systems Incorporated, "Dynamic...Berkeley, Calif. " ___ 1975. "Earthquake Resistant Design of Intake-Outlet Towers," Journal of the Structural Division_ American Society of Civil

Earthquake Response of Concrete Gravity Dams Including Hydrodynamic and Foundation Interaction Effects,

DTIC Science & Technology

1980-01-01

standard procedure for Analysis of all types of civil engineering struc- tures. Early in its development, it became apparent that this method had...unique potentialities in the evaluation of stress in dams, and many of its earliest civil engineering applications concerned special problems associated...with such structures [3,4]. The earliest dynamic finite element analyses of civil engineering structures involved the earthquake response analysis of

A vision-based system for measuring the displacements of large structures: Simultaneous adaptive calibration and full motion estimation

NASA Astrophysics Data System (ADS)

Santos, C. Almeida; Costa, C. Oliveira; Batista, J.

2016-05-01

The paper describes a kinematic model-based solution to estimate simultaneously the calibration parameters of the vision system and the full-motion (6-DOF) of large civil engineering structures, namely of long deck suspension bridges, from a sequence of stereo images captured by digital cameras. Using an arbitrary number of images and assuming a smooth structure motion, an Iterated Extended Kalman Filter is used to recursively estimate the projection matrices of the cameras and the structure full-motion (displacement and rotation) over time, helping to meet the structure health monitoring fulfilment. Results related to the performance evaluation, obtained by numerical simulation and with real experiments, are reported. The real experiments were carried out in indoor and outdoor environment using a reduced structure model to impose controlled motions. In both cases, the results obtained with a minimum setup comprising only two cameras and four non-coplanar tracking points, showed a high accuracy results for on-line camera calibration and structure full motion estimation.

40 CFR 60.4861 - How do I establish an affirmative defense for exceedance of an emission limit or standard during...

Code of Federal Regulations, 2014 CFR

2014-07-01

... affirmative defense to a claim for civil penalties for exceedances of emission limits that are caused by..., using best monitoring methods and engineering judgment, the amount of excess emissions that were the... malfunction, if it wishes to avail itself of an affirmative defense to civil penalties for that malfunction...

40 CFR 60.4861 - How do I establish an affirmative defense for exceedance of an emission limit or standard during...

Code of Federal Regulations, 2013 CFR

2013-07-01

... affirmative defense to a claim for civil penalties for exceedances of emission limits that are caused by..., using best monitoring methods and engineering judgment, the amount of excess emissions that were the... malfunction, if it wishes to avail itself of an affirmative defense to civil penalties for that malfunction...

23 CFR 230.119 - Monitoring of supportive services.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Monitoring of supportive services. 230.119 Section 230.119 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Equal Employment Opportunity on Federal and Federal-Aid Construction Contracts (Including...

23 CFR 230.119 - Monitoring of supportive services.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Monitoring of supportive services. 230.119 Section 230.119 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Equal Employment Opportunity on Federal and Federal-Aid Construction Contracts (Including...

23 CFR 230.119 - Monitoring of supportive services.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Monitoring of supportive services. 230.119 Section 230.119 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Equal Employment Opportunity on Federal and Federal-Aid Construction Contracts (Including...

23 CFR 230.119 - Monitoring of supportive services.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Monitoring of supportive services. 230.119 Section 230.119 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CIVIL RIGHTS EXTERNAL PROGRAMS Equal Employment Opportunity on Federal and Federal-Aid Construction Contracts (Including...

5 CFR 430.207 - Monitoring performance.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Monitoring performance. 430.207 Section 430.207 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Performance Appraisal for General Schedule, Prevailing Rate, and Certain Other Employees § 430.207...

5 CFR 430.207 - Monitoring performance.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Monitoring performance. 430.207 Section 430.207 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Performance Appraisal for General Schedule, Prevailing Rate, and Certain Other Employees § 430.207...

5 CFR 430.207 - Monitoring performance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Monitoring performance. 430.207 Section 430.207 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Performance Appraisal for General Schedule, Prevailing Rate, and Certain Other Employees § 430.207...

A Variational Principle for Reconstruction of Elastic Deformations in Shear Deformable Plates and Shells

NASA Technical Reports Server (NTRS)

Tessler, Alexander; Spangler, Jan L.

2003-01-01

A variational principle is formulated for the inverse problem of full-field reconstruction of three-dimensional plate/shell deformations from experimentally measured surface strains. The formulation is based upon the minimization of a least squares functional that uses the complete set of strain measures consistent with linear, first-order shear-deformation theory. The formulation, which accommodates for transverse shear deformation, is applicable for the analysis of thin and moderately thick plate and shell structures. The main benefit of the variational principle is that it is well suited for C(sup 0)-continuous displacement finite element discretizations, thus enabling the development of robust algorithms for application to complex civil and aeronautical structures. The methodology is especially aimed at the next generation of aerospace vehicles for use in real-time structural health monitoring systems.

Design and initial validation of a wireless control system based on WSN

NASA Astrophysics Data System (ADS)

Yu, Yan; Li, Luyu; Li, Peng; Wang, Xu; Liu, Hang; Ou, Jinping

2013-04-01

At present, cantilever structure used widely in civil structures will generate continuous vibration by external force due to their low damping characteristic, which leads to a serious impact on the working performance and service time. Therefore, it is very important to control the vibration of these structures. The active vibration control is the primary means of controlling the vibration with high precision and strong adaptive ability. Nowadays, there are many researches using piezoelectric materials in the structural vibration control. Piezoelectric materials are cheap, reliable and they can provide braking and sensing method harmless to the structure, therefore they have broad usage. They are used for structural vibration control in a lot of civil engineering research currently. In traditional sensor applications, information exchanges with the monitoring center or a computer system through wires. If wireless sensor networks(WSN) technology is used, cabling links is not needed, thus the cost of the whole system is greatly reduced. Based on the above advantages, a wireless control system is designed and validated through preliminary tests. The system consists of a cantilever, PVDF as sensor, signal conditioning circuit(SCM), A/D acquisition board, control arithmetic unit, D/A output board, power amplifier, piezoelectric bimorph as actuator. DSP chip is used as the control arithmetic unit and PD control algorithm is embedded in it. PVDF collects the parameters of vibration, sends them to the SCM after A/D conversion. SCM passes the data to the DSP through wireless technology, and DSP calculates and outputs the control values according to the control algorithm. The output signal is amplified by the power amplifier to drive the piezoelectric bimorph for vibration control. The structural vibration duration reduces to 1/4 of the uncontrolled case, which verifies the feasibility of the system.

78 FR 68425 - Meeting of the National Commission on the Structure of the Air Force

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-14

... mission sets such as security forces, civil engineering and science and technology. -- Projections and... Defense Support to Civil Agencies. This will include implications for the structure of the Air Force from...

Experimental Investigations on Effect of Damage on Vibration Characteristics of a Reinforced Concrete Beam

NASA Astrophysics Data System (ADS)

Srinivas, V.; Jeyasehar, C. Antony; Ramanjaneyulu, K.; Sasmal, Saptarshi

2012-02-01

Need for developing efficient non-destructive damage assessment procedures for civil engineering structures is growing rapidly towards structural health assessment and management of existing structures. Damage assessment of structures by monitoring changes in the dynamic properties or response of the structure has received considerable attention in recent years. In the present study, damage assessment studies have been carried out on a reinforced concrete beam by evaluating the changes in vibration characteristics with the changes in damage levels. Structural damage is introduced by static load applied through a hydraulic jack. After each stage of damage, vibration testing is performed and system parameters were evaluated from the measured acceleration and displacement responses. Reduction in fundamental frequencies in first three modes is observed for different levels of damage. It is found that a consistent decrease in fundamental frequency with increase in damage magnitude is noted. The beam is numerically simulated and found that the vibration characteristics obtained from the measured data are in close agreement with the numerical data.

Three Dimensional Modeling of Breaking

DTIC Science & Technology

2005-09-30

Three Dimensional Modeling of Breaking Robert A. Dalrymple Dept of Civil Engineering The Johns Hopkins University 3400 North Charles Street...University,Dept of Civil Engineering,3400 North Charles Street,Baltimore,MD,21218 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING...R.A. Dalrymple, A.J.C. Crespo, and D. Cerquiero, "Uso de la Tecnica SPH para el Estudio de la Interaccion entre Olas y Estructuras," Ingenieria del

40 CFR 63.7501 - How can I assert an affirmative defense if I exceed an emission limitations during a malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... operating limits set forth in § 63.7500 you may assert an affirmative defense to a claim for civil penalties... monitoring methods and engineering judgment, the amount of excess emissions that were the result of the... malfunction, if it wishes to avail itself of an affirmative defense to civil penalties for that malfunction...

40 CFR 63.7501 - How can I assert an affirmative defense if I exceed an emission limitations during a malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... operating limits set forth in § 63.7500 you may assert an affirmative defense to a claim for civil penalties... monitoring methods and engineering judgment, the amount of excess emissions that were the result of the... malfunction, if it wishes to avail itself of an affirmative defense to civil penalties for that malfunction...

Data driven innovations in structural health monitoring

NASA Astrophysics Data System (ADS)

Rosales, M. J.; Liyanapathirana, R.

2017-05-01

At present, substantial investments are being allocated to civil infrastructures also considered as valuable assets at a national or global scale. Structural Health Monitoring (SHM) is an indispensable tool required to ensure the performance and safety of these structures based on measured response parameters. The research to date on damage assessment has tended to focus on the utilization of wireless sensor networks (WSN) as it proves to be the best alternative over the traditional visual inspections and tethered or wired counterparts. Over the last decade, the structural health and behaviour of innumerable infrastructure has been measured and evaluated owing to several successful ventures of implementing these sensor networks. Various monitoring systems have the capability to rapidly transmit, measure, and store large capacities of data. The amount of data collected from these networks have eventually been unmanageable which paved the way to other relevant issues such as data quality, relevance, re-use, and decision support. There is an increasing need to integrate new technologies in order to automate the evaluation processes as well as to enhance the objectivity of data assessment routines. This paper aims to identify feasible methodologies towards the application of time-series analysis techniques to judiciously exploit the vast amount of readily available as well as the upcoming data resources. It continues the momentum of a greater effort to collect and archive SHM approaches that will serve as data-driven innovations for the assessment of damage through efficient algorithms and data analytics.

Using inertial measurement units originally developed for biomechanics for modal testing of civil engineering structures

NASA Astrophysics Data System (ADS)

Hester, David; Brownjohn, James; Bocian, Mateusz; Xu, Yan; Quattrone, Antonino

2018-05-01

This paper explores the use of wireless Inertial Measurement Units (IMU) originally developed for bio-mechanical research applications for modal testing of civil engineering infrastructure. Due to their biomechanics origin, these devices combine a triaxial accelerometer with gyroscopes and magnetometers for orientation, as well as on board data logging capability and wireless communication for optional data streaming and to coordinate synchronisation with other IMUs in a network. The motivation for application to civil structures is that their capabilities and simple operating procedures make them suitable for modal testing of many types of civil infrastructure of limited dimension including footbridges and floors while also enabling recovering of dynamic forces generated and applied to structures by moving humans. To explore their capabilities in civil applications, the IMUs are evaluated through modal tests on three different structures with increasing challenge of spatial and environmental complexity. These are, a full-scale floor mock-up in a laboratory, a short span road bridge and a seven story office tower. For each case, the results from the IMUs are compared with those from a conventional wired system to identify the limitations. The main conclusion is that the relatively high noise floor and limited communication range will not be a serious limitation in the great majority of typical civil modal test applications where convenient operation is a significant advantage over conventional wired systems.

Influence of Axial Load on Electromechanical Impedance (EMI) of Embedded Piezoceramic Transducers in Steel Fiber Concrete.

PubMed

Wang, Zhijie; Chen, Dongdong; Zheng, Liqiong; Huo, Linsheng; Song, Gangbing

2018-06-01

With the advantages of high tensile, bending, and shear strength, steel fiber concrete structures have been widely used in civil engineering. The health monitoring of concrete structures, including steel fiber concrete structures, receives increasing attention, and the Electromechanical Impedance (EMI)-based method is commonly used. Structures are often subject to changing axial load and ignoring the effect of axial forces may introduce error to Structural Health Monitoring (SHM), including the EMI-based method. However, many of the concrete structure monitoring algorithms do not consider the effects of axial loading. To investigate the influence of axial load on the EMI of a steel fiber concrete structure, concrete specimens with different steel fiber content (0, 30, 60, 90, 120) (kg/m³) were casted and the Lead Zirconate Titanate (PZT)-based Smart Aggregate (SA) was used as the EMI sensor. During tests, the step-by-step loading procedure was applied on different steel fiber content specimens, and the electromechanical impedance values were measured. The Normalized root-mean-square deviation Index (NI) was developed to analyze the EMI information and evaluate the test results. The results show that the normalized root-mean-square deviation index increases with the increase of the axial load, which clearly demonstrates the influence of axial load on the EMI values for steel fiber concrete and this influence should be considered during a monitoring or damage detection procedure if the axial load changes. In addition, testing results clearly reveal that the steel fiber content, often at low mass and volume percentage, has no obvious influence on the PZT's EMI values. Furthermore, experiments to test the repeatability of the proposed method were conducted. The repeating test results show that the EMI-based indices are repeatable and there is a great linearity between the NI and the applied loading.

Results in standardization of FOS to support the use of SHM systems

NASA Astrophysics Data System (ADS)

Habel, Wolfgang R.; Krebber, Katerina; Daum, Werner

2016-05-01

Measurement and data recording systems are important parts of a holistic Structural Health Monitoring (SHM) system. New sensor technologies such as fiber-optic sensors are often used; however, standards (or at least guidelines) are not yet available or internationally approved. This lack in standardization makes the acceptance of FOS technologies in complex SHM systems substantially difficult. A standard family for different FOS technologies is therefore being developed that should help to design SHM systems in an optimal way. International standardization activities take place in several standardization bodies such as IEC and ASTM, and within SHM societies such as ISHMII. The paper reports on activities in standardization of fiber-optic sensors, on results already achieved, and on newly started projects. Combined activities of fiber sensor experts and SHM experts from Civil Engineering are presented. These contributions should help owners of structures as well as developers of sensors and monitoring systems to select effective and validated sensing technologies. Using these standards, both parties find recommendations how to proceed in development of SHM systems to evaluate the structural behavior based on e.g. standardized fiber optic sensors, and to derive necessary measures, e.g. the optimal maintenance strategy.

Experimental investigation for an isolation technique on conducting the electromechanical impedance method in high-temperature pipeline facilities

NASA Astrophysics Data System (ADS)

Na, Wongi S.; Lee, Hyeonseok

2016-11-01

In general, the pipelines within a nuclear power plant facility may experience high temperatures up to several hundred degrees. Thus it is absolutely vital to monitor these pipes to prevent leakage of radioactive substances which may lead to a catastrophic outcome of the surrounding environment. Over the years, one of the structural health monitoring technique known as the electromechanical impedance (EMI) technique has been of great interests in various fields including civil infrastructures, mechanical and aerospace structures. Although it has one of the best advantages to be able for a single piezoelectric transducer to act as a sensor and an actuator, simultaneously, its low curie temperature makes it difficult for the EMI technique to be conducted at high temperature environment. To overcome this problem, this study shows a method to avoid attaching the piezoelectric transducer directly onto the target structure using a metal wire for damage detection at high temperature. By shifting the frequency to compensate the signature changes subjected to the variations in temperature, the experimental results indicate that damage identification is more successful above 200 oC, making the metal wire method suitable for the EMI technique at high temperature environment.

Assessment and control of structural damage

NASA Technical Reports Server (NTRS)

Jeong, G. D.; Stubbs, N.; Yao, J. T. P.

1988-01-01

The objective of this paper is to summarize and review several investigations on the assessment and control of structural damage in civil engineering. Specifically, the definition of structural damage is discussed. A candidate method for the evaluation of damage is then reviewed and demonstrated. Various ways of implementing passive and active control of civil engineering structures are next summarized. Finally, the possibility of applying expert systems is discussed.

33 CFR 222.4 - Reporting earthquake effects.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF DEFENSE ENGINEERING AND DESIGN § 222.4 Reporting earthquake effects. (a) Purpose. This... structural integrity and operational adequacy of major Civil Works structures following the occurrence of...) Applicability. This regulation is applicable to all field operating agencies having Civil Works responsibilities...

Large scale distribution monitoring of FRP-OF based on BOTDR technique for infrastructures

NASA Astrophysics Data System (ADS)

Zhou, Zhi; He, Jianping; Yan, Kai; Ou, Jinping

2007-04-01

BOTDA(R) sensing technique is considered as one of the most practical solution for large-sized structures as the instrument. However, there is still a big obstacle to apply BOTDA(R) in large-scale area due to the high cost and the reliability problem of sensing head which is associated to the sensor installation and survival. In this paper, we report a novel low-cost and high reliable BOTDA(R) sensing head using FRP(Fiber Reinforced Polymer)-bare optical fiber rebar, named BOTDA(R)-FRP-OF. We investigated the surface bonding and its mechanical strength by SEM and intensity experiments. Considering the strain difference between OF and host matrix which may result in measurement error, the strain transfer from host to OF have been theoretically studied. Furthermore, GFRP-OFs sensing properties of strain and temperature at different gauge length were tested under different spatial and readout resolution using commercial BOTDA. Dual FRP-OFs temperature compensation method has also been proposed and analyzed. And finally, BOTDA(R)-OFs have been applied in Tiyu west road civil structure at Guangzhou and Daqing Highway. This novel FRP-OF rebar shows both high strengthen and good sensing properties, which can be used in long-term SHM for civil infrastructures.

Fatigue crack monitoring with coupled piezoelectric film acoustic emission sensors

NASA Astrophysics Data System (ADS)

Zhou, Changjiang

Fatigue-induced cracking is a commonly seen problem in civil infrastructures reaching their original design life. A number of high-profile accidents have been reported in the past that involved fatigue damage in structures. Such incidences often happen without prior warnings due to lack of proper crack monitoring technique. In order to detect and monitor the fatigue crack, acoustic emission (AE) technique, has been receiving growing interests recently. AE can provide continuous and real-time monitoring data on damage progression in structures. Piezoelectric film AE sensor measures stress-wave induced strain in ultrasonic frequency range and its feasibility for AE signal monitoring has been demonstrated recently. However, extensive work in AE monitoring system development based on piezoelectric film AE sensor and sensor characterization on full-scale structures with fatigue cracks, have not been done. A lack of theoretical formulations for understanding the AE signals also hinders the use of piezoelectric film AE sensors. Additionally, crack detection and source localization with AE signals is a very important area yet to be explored for this new type of AE sensor. This dissertation presents the results of both analytical and experimental study on the signal characteristics of surface stress-wave induced AE strain signals measured by piezoelectric film AE sensors in near-field and an AE source localization method based on sensor couple theory. Based on moment tensor theory, generalized expression for AE strain signal is formulated. A special case involving the response of piezoelectric film AE sensor to surface load is also studied, which could potentially be used for sensor calibration of this type of sensor. A new concept of sensor couple theory based AE source localization technique is proposed and validated with both simulated and experimental data from fatigue test and field monitoring. Two series of fatigue tests were conducted to perform fatigue crack monitoring on large-scale steel test specimens using piezoelectric film AE sensors. Continuous monitoring of fatigue crack growth in steel structures is demonstrated in these fatigue test specimens. The use of piezoelectric film AE sensor for field monitoring of existing fatigue crack is also demonstrated in a real steel I-girder bridge located in Maryland. The sensor couple theory based AE source localization is validated using a limited number of piezoelectric film AE sensor data from both fatigue test specimens and field monitoring bridge. Through both laboratory fatigue test and field monitoring of steel structures with active fatigue cracks, the signal characteristics of piezoelectric film AE sensor have been studied in real-world environment.

Application of outlier analysis for baseline-free damage diagnosis

NASA Astrophysics Data System (ADS)

Kim, Seung Dae; In, Chi Won; Cronin, Kelly E.; Sohn, Hoon; Harries, Kent

2006-03-01

As carbon fiber-reinforced polymer (CFRP) laminates have been widely accepted as valuable materials for retrofitting civil infrastructure systems, an appropriate assessment of bonding conditions between host structures and CFRP laminates becomes a critical issue to guarantee the performance of CFRP strengthened structures. This study attempts to develop a continuous performance monitoring system for CFRP strengthened structures by autonomously inspecting the bonding conditions between the CFRP layers and the host structure. The uniqueness of this study is to develop a new concept and theoretical framework of nondestructive testing (NDT), in which debonding is detected "without using past baseline data." The proposed baseline-free damage diagnosis is achieved in two stages. In the first step, features sensitive to debonding of the CFPR layers but insensitive to loading conditions are extracted based on a concept referred to as a time reversal process. This time reversal process allows extracting damage-sensitive features without direct comparison with past baseline data. Then, a statistical damage classifier will be developed in the second step to make a decision regarding the bonding condition of the CFRP layers. The threshold necessary for decision making will be adaptively determined without predetermined threshold values. Monotonic and fatigue load tests of full-scale CFRP strengthened RC beams are conducted to demonstrate the potential of the proposed reference-free debonding monitoring system.

Monitoring of Concrete Structures Using Ofdr Technique

NASA Astrophysics Data System (ADS)

Henault, J. M.; Salin, J.; Moreau, G.; Delepine-Lesoille, S.; Bertand, J.; Taillade, F.; Quiertant, M.; Benzarti, K.

2011-06-01

Structural health monitoring is a key factor in life cycle management of infrastructures. Truly distributed fiber optic sensors are able to provide relevant information on large structures, such as bridges, dikes, nuclear power plants or nuclear waste disposal facilities. The sensing chain includes an optoelectronic unit and a sensing cable made of one or more optical fibers. A new instrument based on Optical Frequency Domain Reflectometry (OFDR), enables to perform temperature and strain measurements with a centimeter scale spatial resolution over hundred of meters and with a level of precision equal to 1 μstrain and 0.1 °C. Several sensing cables are designed with different materials targeting to last for decades in a concrete aggressive environment and to ensure an optimal transfer of temperature and strain from the concrete matrix to the optical fiber. Tests were carried out by embedding various sensing cables into plain concrete specimens and representative-scale reinforced concrete structural elements. Measurements were performed with an OFDR instrument; meanwhile, mechanical solicitations were imposed to the concrete element. Preliminary experiments are very promising since measurements performed with distributed sensing system are comparable to values obtained with conventional sensors used in civil engineering and with the Strength of Materials Modelling. Moreover, the distributed sensing system makes it possible to detect and localize cracks appearing in concrete during the mechanical loading.

Structural health monitoring of cylindrical bodies under impulsive hydrodynamic loading by distributed FBG strain measurements

NASA Astrophysics Data System (ADS)

Fanelli, Pierluigi; Biscarini, Chiara; Jannelli, Elio; Ubertini, Filippo; Ubertini, Stefano

2017-02-01

Various mechanical, ocean, aerospace and civil engineering problems involve solid bodies impacting the water surface and often result in complex coupled dynamics, characterized by impulsive loading conditions, high amplitude vibrations and large local deformations. Monitoring in such problems for purposes such as remaining fatigue life estimation and real time damage detection is a technical and scientific challenge of primary concern in this context. Open issues include the need for developing distributed sensing systems able to operate at very high acquisition frequencies, to be utilized to study rapidly varying strain fields, with high resolution and very low noise, while scientific challenges mostly relate to the definition of appropriate signal processing and modeling tools enabling the extraction of useful information from distributed sensing signals. Building on previous work by some of the authors, we propose an enhanced method for real time deformed shape reconstruction using distributed FBG strain measurements in curved bodies subjected to impulsive loading and we establish a new framework for applying this method for structural health monitoring purposes, as the main focus of the work. Experiments are carried out on a cylinder impacting the water at various speeds, proving improved performance in displacement reconstruction of the enhanced method compared to its previous version. A numerical study is then carried out considering the same physical problem with different delamination damages affecting the body. The potential for detecting, localizing and quantifying this damage using the reconstruction algorithm is thoroughly investigated. Overall, the results presented in the paper show the potential of distributed FBG strain measurements for real time structural health monitoring of curved bodies under impulsive hydrodynamic loading, defining damage sensitive features in terms of strain or displacement reconstruction errors at selected locations along the structure.

Environmental effects on natural frequencies of the San Pietro bell tower in Perugia, Italy, and their removal for structural performance assessment

NASA Astrophysics Data System (ADS)

Ubertini, Filippo; Comanducci, Gabriele; Cavalagli, Nicola; Laura Pisello, Anna; Luigi Materazzi, Annibale; Cotana, Franco

2017-01-01

Continuously identified natural frequencies of vibration can provide unique information for low-cost automated condition assessment of civil constructions and infrastructures. However, the effects of changes in environmental parameters, such as temperature and humidity, need to be effectively investigated and accurately removed from identified frequency data for an effective performance assessment. This task is particularly challenging in the case of historical constructions that are typically massive and heterogeneous masonry structures characterized by complex variations of materials' properties with varying environmental parameters and by a differential heat conduction process where thermal capacity plays a major role. While there is abundance of documented monitoring data highlighting correlations between environmental parameters and natural frequencies in the case of new structures, such as long-span bridges, similar studies for historical constructions are still missing, with only a few literature works occasionally reporting increments in natural frequencies with increasing temperature of construction materials due to the closure of internal micro-cracks in the mortar layers caused by thermal expansion. In order to gain some knowledge on the effects of changes in temperature and humidity on the natural frequencies of slender masonry buildings, the paper focuses on the case study of an Italian monumental bell tower that has been monitored by the authors for more than nine months. Correlations between natural frequencies and environmental parameters are investigated in detail and the predictive capabilities of linear statistical regressive models based on the use of several environmental continuous monitoring sensors are assessed. At the end, three basic mechanisms governing environmentally-induced changes in the dynamic behavior of the tower are identified and essential information is achieved on the optimal location and minimum number of environmental sensors that are necessary in a structural health monitoring perspective.

Earthquakes: Natural Science Museum and Civil Protection of Trento to inform citizens

NASA Astrophysics Data System (ADS)

Lauro, Claudia; Avanzini, Marco

2010-05-01

During 2009 the Natural Science Museum of Trento organized the exhibition "Attraction Earth: Earthquakes and Terrestrial Magnetism" in collaboration with the INGV (Italian National Institute of Geophysic and Volcanology). In this exhibition a particular sector has been devoted to the seismic activity and its monitoring in the Province of Trento. The purpose was to inform local people on the geological features of their territory, the monitoring activity carried out by the Civil Protection and the potential earthquake hazards, also in order to adopt a correct behaviour in case of seismic event. This sector, "The seismometric Trentino network", was organized by the Geological Service of the Trento Civil Protection and it is open till May 2010, both for general public and school students. For the latter, a particular education pack, realized by the Educational Department of the Museum and consisting of a guided tour coupled with the laboratory activity "Waves upside-down: seismology", is proposed. The whole exhibition has been also coupled with a cycle conferences targeted to adults, in which these topics have been explained by researchers and technicians of INGV and of Trento Geological Service. "The seismometric Trentino network" sector presents the daily monitoring activity of the Geological Service, that has been monitoring the seismic activity for the last 30 years, and describes the deep earth processes of the local territory, such as presence of tectonic discontinuities and their activity. It consists of display panels, a seismometer with rotating drums and a multimedia that reports the monitoring activity of the seismometric network, with real time connection to the various monitoring stations. This allows visitors to observe instantly the local seismic events recorded by each station. The seismometric network was established by the institutions of Trento Province after the earthquakes occurred in Friuli Venezia-Giulia and at Riva del Garda (1976). It started its activity in 1981 and consists of 7 stations equipped with seismometers and acquisition digital technology, working 24 hours per day. Moreover, a network of 9 accelerometers has been set up in the southern Trentino, where most of the seismic events are concentrated. All the information revealed in each station flow to the "Data Acquisition Central Office", where the data are checked, processed and recorded. The Geological Service manages the seismometric network, elaborates and publishes the information regarding the seismicity of the area and surroundings. In case of earthquake the "Seismic Alert", an automatic alarm system, is activated to Civil Protection purposes. The "Seismic Alert" is managed by "Antilope", the consortium of the Eastern Alpine seismometric networks. Moreover the seismotectonic is another research field carried out by this Geological Service, to investigate the formation mechanism of earthquakes and estimate the causative tectonic stress, in relation to the main tectonic structures of the region and of the whole Alpine chain. Hence the Trento study-case reported in this exhibition illustrates the general methodology used to understand the "seismic behaviour" of a region. At the end this exhibition sector also presents the activity of the Trento Civil Protection in the Abruzzo region, where a dramatic seismic event occurred on 6th April 2009, describing the investigation of the still occurring surface deformations. This activity is part of a general framework in which the Trento Province provided first aid and assistance to the local communities. The collaboration between the Natural Science Tridentino Museum and the Geological Service of Trento, already fruitful on field geological researches, has been also effective in this project of science communication. In the future the two institutions could collaborate in other main themes of the relationship between science and society, regarding the dissemination of Earth Sciences.

Development of an In-Situ Decommissioning Sensor Network Test Bed for Structural Condition Monitoring - 12156

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeigler, Kristine E.; Ferguson, Blythe A.

2012-07-01

The Savannah River National Laboratory (SRNL) has established an In Situ Decommissioning (ISD) Sensor Network Test Bed, a unique, small scale, configurable environment, for the assessment of prospective sensors on actual ISD system material, at minimal cost. The Department of Energy (DOE) is presently implementing permanent entombment of contaminated, large nuclear structures via ISD. The ISD end state consists of a grout-filled concrete civil structure within the concrete frame of the original building. Validation of ISD system performance models and verification of actual system conditions can be achieved through the development a system of sensors to monitor the materials andmore » condition of the structure. The ISD Sensor Network Test Bed has been designed and deployed to addresses the DOE-Environmental Management Technology Need to develop a remote monitoring system to determine and verify ISD system performance. Commercial off-the-shelf sensors have been installed on concrete blocks taken from walls of the P Reactor Building at the Savannah River Site. Deployment of this low-cost structural monitoring system provides hands-on experience with sensor networks. The initial sensor system consists of groutable thermistors for temperature and moisture monitoring, strain gauges for crack growth monitoring, tilt-meters for settlement monitoring, and a communication system for data collection. Baseline data and lessons learned from system design and installation and initial field testing will be utilized for future ISD sensor network development and deployment. The Sensor Network Test Bed at SRNL uses COTS sensors on concrete blocks from the outer wall of the P Reactor Building to measure conditions expected to occur in ISD structures. Knowledge and lessons learned gained from installation, testing, and monitoring of the equipment will be applied to sensor installation in a meso-scale test bed at FIU and in future ISD structures. The initial data collected from the sensors installed on the P Reactor Building blocks define the baseline materials condition of the P Reactor ISD external concrete structure. Continued monitoring of the blocks will enable evaluation of the effects of aging on the P Reactor ISD structure. The collected data will support validation of the material degradation model and assessment of the condition of the ISD structure over time. The following are recommendations for continued development of the ISD Sensor Network Test Bed: - Establish a long-term monitoring program using the concrete blocks with existing sensor and/or additional sensors for trending the concrete materials and structural condition; - Continue development of a stand-alone test bed sensor system that is self-powered and provides wireless transmission of data to a user-accessible dashboard; - Develop and implement periodic NDE/DE characterization of the concrete blocks to provide verification and validation for the measurements obtained through the sensor system and concrete degradation model(s). (authors)« less

Decision support methodology to establish priorities on the inspection of structures

NASA Astrophysics Data System (ADS)

Cortes, V. Juliette; Sterlacchini, Simone; Bogaard, Thom; Frigerio, Simone; Schenato, Luca; Pasuto, Alessandro

2014-05-01

For hydro-meteorological hazards in mountain areas, the regular inspection of check dams and bridges is important due to the effect of their functional status on water-sediment processes. Moreover, the inspection of these structures is time consuming for organizations due to their extensive number in many regions. However, trained citizen-volunteers can support civil protection and technical services in the frequency, timeliness and coverage of monitoring the functional status of hydraulic structures. Technicians should evaluate and validate these reports to get an index for the status of the structure. Thus, preventive actions could initiate such as the cleaning of obstructions or to pre-screen potential problems for a second level inspection. This study proposes a decision support methodology that technicians can use to assess an index for three parameters representing the functional status of the structure: a) condition of the structure at the opening of the stream flow, b) level of obstruction at the structure and c) the level of erosion in the stream bank. The calculation of the index for each parameter is based upon fuzzy logic theory to handle ranges in precision of the reports and to convert the linguistic rating scales into numbers representing the structure's status. A weighting method and multi-criteria method (Analytic Hierarchy Process- AHP and TOPSIS), can be used by technicians to combine the different ratings according to the component elements of the structure and the completeness of the reports. Finally, technicians can set decision rules based on the worst rating and a threshold for the functional indexes. The methodology was implemented as a prototype web-based tool to be tested with technicians of the Civil Protection in the Fella basin, Northern Italy. Results at this stage comprise the design and implementation of the web-based tool with GIS interaction to evaluate available reports and to set priorities on the inspection of structures. Keywords Decision-making, Multi-criteria methods, Torrent control structures, Web-based tools.

Eco-analytical Methodology in Environmental Problems Monitoring

NASA Astrophysics Data System (ADS)

Agienko, M. I.; Bondareva, E. P.; Chistyakova, G. V.; Zhironkina, O. V.; Kalinina, O. I.

2017-01-01

Among the problems common to all mankind, which solutions influence the prospects of civilization, the problem of ecological situation monitoring takes very important place. Solution of this problem requires specific methodology based on eco-analytical comprehension of global issues. Eco-analytical methodology should help searching for the optimum balance between environmental problems and accelerating scientific and technical progress. The fact that Governments, corporations, scientists and nations focus on the production and consumption of material goods cause great damage to environment. As a result, the activity of environmentalists is developing quite spontaneously, as a complement to productive activities. Therefore, the challenge posed by the environmental problems for the science is the formation of geo-analytical reasoning and the monitoring of global problems common for the whole humanity. So it is expected to find the optimal trajectory of industrial development to prevent irreversible problems in the biosphere that could stop progress of civilization.

Identification of unusual events in multi-channel bridge monitoring data

NASA Astrophysics Data System (ADS)

Omenzetter, Piotr; Brownjohn, James Mark William; Moyo, Pilate

2004-03-01

Continuously operating instrumented structural health monitoring (SHM) systems are becoming a practical alternative to replace visual inspection for assessment of condition and soundness of civil infrastructure such as bridges. However, converting large amounts of data from an SHM system into usable information is a great challenge to which special signal processing techniques must be applied. This study is devoted to identification of abrupt, anomalous and potentially onerous events in the time histories of static, hourly sampled strains recorded by a multi-sensor SHM system installed in a major bridge structure and operating continuously for a long time. Such events may result, among other causes, from sudden settlement of foundation, ground movement, excessive traffic load or failure of post-tensioning cables. A method of outlier detection in multivariate data has been applied to the problem of finding and localising sudden events in the strain data. For sharp discrimination of abrupt strain changes from slowly varying ones wavelet transform has been used. The proposed method has been successfully tested using known events recorded during construction of the bridge, and later effectively used for detection of anomalous post-construction events.

Civil Courts.

ERIC Educational Resources Information Center

Eaneman, Paulette S.; And Others

These materials are part of the Project Benchmark series designed to teach secondary students about our legal concepts and systems. This unit focuses on the structure and procedures of the civil court systems. The materials outline common law heritage, kinds of cases, jurisdiction, civil pretrial procedure, trial procedure, and a sample automobile…

Theoretical and experimental study on fiber-optic displacement sensor with bowknot bending modulation

NASA Astrophysics Data System (ADS)

Zheng, Yong; Huang, Da; Zhu, Zheng-Wei

2018-03-01

A novel and simple fiber-optic sensor for measuring a large displacement range in civil engineering has been developed. The sensor incorporates an extremely simple bowknot bending modulation that increases its sensitivity in bending, light source and detector. In this paper, to better understand the working principle and improve the performance of the sensor, the transduction of displacement to light loss is described analytically by using the geometry of sensor and principle of optical fiber loss. Results of the calibration tests show a logarithmic function relationship between light loss and displacement with two calibrated parameters. The sensor has a response over a wide displacement range of 44.7 mm with an initial accuracy of 2.65 mm, while for a small displacement range of 34 mm it shows a more excellent accuracy of 0.98 mm. The direct shear tests for the six models with the same dimensions were conducted to investigate the application of the sensor for warning the shear and sliding failure in civil engineering materials or geo-materials. Results address that the sliding displacement of sliding body can be relatively accurately captured by the theory logarithmic relation between sliding distance and optical loss in a definite structure, having a large dynamic range of 22.32 mm with an accuracy of 0.99 mm, which suggests that the sensor has a promising prospect in monitoring civil engineering, especially for landslides.

77 FR 66073 - Availability of Seats for the Monitor National Marine Sanctuary Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-01

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Availability of Seats for... (ONMS), National Ocean Service (NOS), National Oceanic and Atmospheric Administration (NOAA), Department.... It is one of 13 sanctuaries and protects the wreck of the famed Civil War ironclad, USS Monitor, best...

78 FR 10606 - Final Management Plan and Environmental Assessment for Monitor National Marine Sanctuary: Notice...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-14

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Final Management Plan and... Administration (NOAA), Department of Commerce (DOC). ACTION: Notice of public availability. SUMMARY: NOAA is... the wreck of the famed Civil War ironclad, USS Monitor, best known for its battle with the Confederate...

Polymer optical fiber sensors in human life safety

NASA Astrophysics Data System (ADS)

Marques, C. A. F.; Webb, D. J.; Andre, P.

2017-07-01

The current state of research into polymer optical fiber (POF) sensors linked to safety in human life is summarized in this paper. This topic is directly related with new solutions for civil aircraft, structural health monitoring, healthcare and biomedicine fields. In the last years, the properties of polymers have been explored to identify situations offering potential advantages over conventional silica fiber sensing technology, replacing, in some cases, problematic electronic technology used in these mentioned fields, where there are some issues to overcome. POFs could preferably replace their silica counterparts, with improved performance and biocompatibility. Finally, new developments are reported which use the unique properties of POF.

Gen-2 RFID compatible, zero down-time, programmable mechanical strain-monitors and mechanical impact detectors

NASA Astrophysics Data System (ADS)

Chakrabartty, Shantanu; Feng, Tao; Aono, Kenji

2013-04-01

A key challenge in structural health monitoring (SHM) sensors embedded inside civil structures is that elec- tronics need to operate continuously such that mechanical events of interest can be detected and appropriately analyzed. Continuous operation however requires a continuous source of energy which cannot be guaranteed using conventional energy scavenging techniques. The paper describes a hybrid energy scavenging SHM sensor which experiences zero down-time in monitoring mechanical events of interest. At the core of the proposed sensor is an analog floating-gate storage technology that can be precisely programmed at nano-watt and pico- watt power levels. This facilitates self-powered, non-volatile data logging of the mechanical events of interest by scavenging energy directly from the mechanical events itself. Remote retrieval of the stored data is achieved using a commercial off-the-shelf Gen-2 radio-frequency identification (RFID) reader which periodically reads an electronic product code (EPC) that encapsulates the sensor data. The Gen-2 interface also facilitates in simultaneous remote access to multiple sensors and also facilitates in determining the range and orientation of the sensor. The architecture of the sensor is based on a token-ring topology which enables sensor channels to be dynamically added or deleted through software control.

Work Experience, Socialization, and Civil Liberties

ERIC Educational Resources Information Center

Korman, Abraham K.

1975-01-01

Examines the effects of work experience on attitudes and behaviors in the area of civil liberties; (1) noting that hierarchical structure, rigidity and specialization seem to generate negative effect toward civil libertarian concerns, and (2) proposing a theoretical model designed to predict the conditions under which work experience may be…

Increasing civil society participation in the national HIV response: the role of UNGASS reporting.

PubMed

Peersman, Greet; Ferguson, Laura; Torres, Mary Ann; Smith, Sally; Gruskin, Sofia

2009-12-01

The 2001 Declaration of Commitment on HIV/AIDS provided impetus for strengthening collaboration between government and civil society partners in the HIV response. The biennial UNGASS reporting process is an opportunity for civil society to engage in a review of the implementation of commitments. Descriptive analyses of the National Composite Policy Index from 135 countries; a debriefing on UNGASS reporting with civil society in 40 countries; and 3 country case studies on the UNGASS process. In the latest UNGASS reporting round, engagement of civil society occurred in the vast majority of countries. The utility of UNGASS reporting seemed to be better understood by both government and civil society, compared with previous reporting rounds. Civil society participation was strongest when civil society groupings took the initiative and organized themselves. An important barrier was their lack of experience with national level processes. Civil society involvement in national HIV planning and strategic processes was perceived to be good, but better access to funding and technical support is needed. Instances remain where there are fundamental differences between government and civil society perceptions of the HIV policy and program environment. How or whether differences were resolved is not always clear, but both government and civil society seemed to appreciate the opportunity for discussion. Collaborative reporting by government and civil society on UNGASS indicators is a small but potentially valuable step in what should be an ongoing and fully institutionalized process of collaborative planning, implementation, monitoring, assessment and correction of HIV responses. The momentum achieved through the UNGASS process should be maintained with follow-up actions to address data gaps, formalize partnerships and enhance active and meaningful engagement.

Automated crack detection in conductive smart-concrete structures using a resistor mesh model

NASA Astrophysics Data System (ADS)

Downey, Austin; D'Alessandro, Antonella; Ubertini, Filippo; Laflamme, Simon

2018-03-01

Various nondestructive evaluation techniques are currently used to automatically detect and monitor cracks in concrete infrastructure. However, these methods often lack the scalability and cost-effectiveness over large geometries. A solution is the use of self-sensing carbon-doped cementitious materials. These self-sensing materials are capable of providing a measurable change in electrical output that can be related to their damage state. Previous work by the authors showed that a resistor mesh model could be used to track damage in structural components fabricated from electrically conductive concrete, where damage was located through the identification of high resistance value resistors in a resistor mesh model. In this work, an automated damage detection strategy that works through placing high value resistors into the previously developed resistor mesh model using a sequential Monte Carlo method is introduced. Here, high value resistors are used to mimic the internal condition of damaged cementitious specimens. The proposed automated damage detection method is experimentally validated using a 500 × 500 × 50 mm3 reinforced cement paste plate doped with multi-walled carbon nanotubes exposed to 100 identical impact tests. Results demonstrate that the proposed Monte Carlo method is capable of detecting and localizing the most prominent damage in a structure, demonstrating that automated damage detection in smart-concrete structures is a promising strategy for real-time structural health monitoring of civil infrastructure.

Who Goes to School? School Enrollment Patterns in Somalia

ERIC Educational Resources Information Center

Moyi, Peter

2012-01-01

Somalia gained its independence in 1960; however, civil conflict broke out in 1991. The outbreak of civil conflict was the final blow for already collapsed education in Somalia. The civil conflict completely destroyed the remaining educational structure. Despite the protracted nature of the conflict Somalia has slowly been pushed out of the active…

Advanced DInSAR analysis for building damage assessment in large urban areas: an application to the city of Roma, Italy

NASA Astrophysics Data System (ADS)

D'Aranno, Peppe J. V.; Marsella, Maria; Scifoni, Silvia; Scutti, Marianna; Sonnessa, Alberico; Bonano, Manuela

2015-10-01

Remote sensing data play an important role for the environmental monitoring because they allow to provide systematic information on very large areas and for a long period of time. Such information must be analyzed, validated and incorporated into proper modeling tools in order to become useful for performing risk assessment analysis. These approaches has been already applied in the field of natural hazard evaluation (i.e. for monitoring seismic, volcanic areas and landslides). However, not enough attention has been devoted to the development of validated methods for implementing quantitative analysis on civil structures. This work is dedicated to the comprehensive utilization of ERS / ENVISAT data store ESA SAR used to detect deformation trends and perform back-analysis of the investigated structures useful to calibrate the damage assessment models. After this preliminary analysis, SAR data of the new satellite mission (ie Cosmo SkyMed) were adopted to monitor the evolution of existent surface deformation processes and to detect new occurrence. The specific objective was to set up a data processing and data analysis chain tailored on a service that sustains the safe maintenance of the built-up environment, including critical construction such as public (schools, hospital, etc), strategic (dam, highways, etc) and also the cultural heritage sites. The analysis of the test area, in the southeastern sector of Roma, has provided three different levels and sub-levels of products from metropolitan area scale (territorial analysis), settlement scale (aggregated analysis) to single structure scale (damage degree associated to the structure).

Geometric identification and damage detection of structural elements by terrestrial laser scanner

NASA Astrophysics Data System (ADS)

Hou, Tsung-Chin; Liu, Yu-Wei; Su, Yu-Min

2016-04-01

In recent years, three-dimensional (3D) terrestrial laser scanning technologies with higher precision and higher capability are developing rapidly. The growing maturity of laser scanning has gradually approached the required precision as those have been provided by traditional structural monitoring technologies. Together with widely available fast computation for massive point cloud data processing, 3D laser scanning can serve as an efficient structural monitoring alternative for civil engineering communities. Currently most research efforts have focused on integrating/calculating the measured multi-station point cloud data, as well as modeling/establishing the 3D meshes of the scanned objects. Very little attention has been spent on extracting the information related to health conditions and mechanical states of structures. In this study, an automated numerical approach that integrates various existing algorithms for geometric identification and damage detection of structural elements were established. Specifically, adaptive meshes were employed for classifying the point cloud data of the structural elements, and detecting the associated damages from the calculated eigenvalues in each area of the structural element. Furthermore, kd-tree was used to enhance the searching efficiency of plane fitting which were later used for identifying the boundaries of structural elements. The results of geometric identification were compared with M3C2 algorithm provided by CloudCompare, as well as validated by LVDT measurements of full-scale reinforced concrete beams tested in laboratory. It shows that 3D laser scanning, through the established processing approaches of the point cloud data, can offer a rapid, nondestructive, remote, and accurate solution for geometric identification and damage detection of structural elements.

An introduction to structural health monitoring.

PubMed

Farrar, Charles R; Worden, Keith

2007-02-15

The process of implementing a damage identification strategy for aerospace, civil and mechanical engineering infrastructure is referred to as structural health monitoring (SHM). Here, damage is defined as changes to the material and/or geometric properties of these systems, including changes to the boundary conditions and system connectivity, which adversely affect the system's performance. A wide variety of highly effective local non-destructive evaluation tools are available for such monitoring. However, the majority of SHM research conducted over the last 30 years has attempted to identify damage in structures on a more global basis. The past 10 years have seen a rapid increase in the amount of research related to SHM as quantified by the significant escalation in papers published on this subject. The increased interest in SHM and its associated potential for significant life-safety and economic benefits has motivated the need for this theme issue. This introduction begins with a brief history of SHM technology development. Recent research has begun to recognize that the SHM problem is fundamentally one of the statistical pattern recognition (SPR) and a paradigm to address such a problem is described in detail herein as it forms the basis for organization of this theme issue. In the process of providing the historical overview and summarizing the SPR paradigm, the subsequent articles in this theme issue are cited in an effort to show how they fit into this overview of SHM. In conclusion, technical challenges that must be addressed if SHM is to gain wider application are discussed in a general manner.

Photocopy of plan (in collection of U.S. Coast Guard Civil ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of plan (in collection of U.S. Coast Guard Civil Engineering Unit Providence, Warwick, RI), U.S. Engineer Office, New York District, military reservation location of fortification structures, map no. 1, Fort Hanconck, New Jersey, July 29, 1944 Detail of western docking structure - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

The development of human factors research objectives for civil aviation

NASA Technical Reports Server (NTRS)

Post, T. J.

1970-01-01

Human factors research programs which would support civil aviation and be suitable for accomplishment by NASA research centers are identified. Aviation problems formed the basis for the research program recommendations and, accordingly, problems were identified, ranked and briefly defined in an informal report to the project monitor and other cognizant NASA personnel. The sources for this problem foundation were literature reviews and extensive interviews with NASA and non-NASA personnel. An overview of these findings is presented.

Evaluation of concrete cover by surface wave technique: Identification procedure

NASA Astrophysics Data System (ADS)

Piwakowski, Bogdan; Kaczmarek, Mariusz; Safinowski, Paweł

2012-05-01

Concrete cover degradation is induced by aggressive agents in ambiance, such as moisture, chemicals or temperature variations. Due to degradation usually a thin (a few millimeters thick) surface layer has porosity slightly higher than the deeper sound material. The non destructive evaluation of concrete cover is vital to monitor the integrity of concrete structures and prevent their irreversible damage. In this paper the methodology applied by the classical technique used for ground structure recovery called Multichanel Analysis of Surface Waves is discussed as the NDT tool in civil engineering domain to characterize the concrete cover. In order to obtain the velocity as a function of sample depth the dispersion of surface waves is used as an input for solving inverse problem. The paper describes the inversion procedure and provides the practical example of use of developed system.

GB-InSAR monitoring of slope deformations in a mountainous area affected by debris flow events

NASA Astrophysics Data System (ADS)

Frodella, William; Salvatici, Teresa; Pazzi, Veronica; Morelli, Stefano; Fanti, Riccardo

2017-10-01

Diffuse and severe slope instabilities affected the whole Veneto region (north-eastern Italy) between 31 October and 2 November 2010, following a period of heavy and persistent rainfall. In this context, on 4 November 2010 a large detrital mass detached from the cover of the Mt. Rotolon deep-seated gravitational slope deformation (DSGSD), located in the upper Agno River valley, channelizing within the Rotolon Creek riverbed and evolving into a highly mobile debris flow. The latter phenomena damaged many hydraulic works, also threatening bridges, local roads, and the residents of the Maltaure, Turcati, and Parlati villages located along the creek banks and the town of Recoaro Terme. From the beginning of the emergency phase, the civil protection system was activated, involving the National Civil Protection Department, Veneto Region, and local administrations' personnel and technicians, as well as scientific institutions. On 8 December 2010 a local-scale monitoring system, based on a ground-based interferometric synthetic aperture radar (GB-InSAR), was implemented in order to evaluate the slope deformation pattern evolution in correspondence of the debris flow detachment sector, with the final aim of assessing the landslide residual risk and managing the emergency phase. This paper describes the results of a 2-year GB-InSAR monitoring campaign (December 2010-December 2012) and its application for monitoring, mapping, and emergency management activities in order to provide a rapid and easy communication of the results to the involved technicians and civil protection personnel, for a better understanding of the landslide phenomena and the decision-making process in a critical landslide scenario.

Analyses of the most influential factors for vibration monitoring of planetary power transmissions in pellet mills by adaptive neuro-fuzzy technique

NASA Astrophysics Data System (ADS)

Milovančević, Miloš; Nikolić, Vlastimir; Anđelković, Boban

2017-01-01

Vibration-based structural health monitoring is widely recognized as an attractive strategy for early damage detection in civil structures. Vibration monitoring and prediction is important for any system since it can save many unpredictable behaviors of the system. If the vibration monitoring is properly managed, that can ensure economic and safe operations. Potentials for further improvement of vibration monitoring lie in the improvement of current control strategies. One of the options is the introduction of model predictive control. Multistep ahead predictive models of vibration are a starting point for creating a successful model predictive strategy. For the purpose of this article, predictive models of are created for vibration monitoring of planetary power transmissions in pellet mills. The models were developed using the novel method based on ANFIS (adaptive neuro fuzzy inference system). The aim of this study is to investigate the potential of ANFIS for selecting the most relevant variables for predictive models of vibration monitoring of pellet mills power transmission. The vibration data are collected by PIC (Programmable Interface Controller) microcontrollers. The goal of the predictive vibration monitoring of planetary power transmissions in pellet mills is to indicate deterioration in the vibration of the power transmissions before the actual failure occurs. The ANFIS process for variable selection was implemented in order to detect the predominant variables affecting the prediction of vibration monitoring. It was also used to select the minimal input subset of variables from the initial set of input variables - current and lagged variables (up to 11 steps) of vibration. The obtained results could be used for simplification of predictive methods so as to avoid multiple input variables. It was preferable to used models with less inputs because of overfitting between training and testing data. While the obtained results are promising, further work is required in order to get results that could be directly applied in practice.

The Federal Civil Rights Enforcement Effort--1974. Volume II: To Provide ... For Fair Housing.

ERIC Educational Resources Information Center

Buckley, Grace M.; And Others

This report evaluates the Civil Rights activities of seven federal agencies with fair housing responsibilities. It is the second of a series of six reports to be issued by the Commission on Civil Rights describing the structure, mechanisms, and procedures utilized by the federal departments and agencies in their effort to end discrimination…

The Federal Civil Rights Enforcement Effort--1974. Volume 5: To Eliminate Employment Discrimination.

ERIC Educational Resources Information Center

Adams, Whitney; And Others

This report evaluates the Civil Rights activities of four federal agencies considered to have major responsibilities for ensuring equal employment opportunity. It is the fifth of a series of seven reports to be issued by the U.S. Commission on Civil Rights describing the structure, mechanisms, and procedures used by the federal departments and…

Acoustic emission monitoring of concrete columns and beams strengthened with fiber reinforced polymer sheets

NASA Astrophysics Data System (ADS)

Ma, Gao; Li, Hui; Zhou, Wensong; Xian, Guijun

2012-04-01

Acoustic emission (AE) technique is an effective method in the nondestructive testing (NDT) field of civil engineering. During the last two decades, Fiber reinforced polymer (FRP) has been widely used in repairing and strengthening concrete structures. The damage state of FRP strengthened concrete structures has become an important issue during the service period of the structure and it is a meaningful work to use AE technique as a nondestructive method to assess its damage state. The present study reports AE monitoring results of axial compression tests carried on basalt fiber reinforced polymer (BFRP) confined concrete columns and three-point-bending tests carried on BFRP reinforced concrete beams. AE parameters analysis was firstly utilized to give preliminary results of the concrete fracture process of these specimens. It was found that cumulative AE events can reflect the fracture development trend of both BFRP confined concrete columns and BFRP strengthened concrete beams and AE events had an abrupt increase at the point of BFRP breakage. Then the fracture process of BFRP confined concrete columns and BFRP strengthened concrete beams was studied through RA value-average frequency analysis. The RA value-average frequency tendencies of BFRP confined concrete were found different from that of BFRP strengthened concrete beams. The variation tendency of concrete crack patterns during the loading process was revealed.

Feasibility of Frequency-Modulated Wireless Transmission for a Multi-Purpose MEMS-Based Accelerometer

PubMed Central

Sabato, Alessandro; Feng, Maria Q.

2014-01-01

Recent advances in the Micro Electro-Mechanical System (MEMS) technology have made wireless MEMS accelerometers an attractive tool for Structural Health Monitoring (SHM) of civil engineering structures. To date, sensors' low sensitivity and accuracy—especially at very low frequencies—have imposed serious limitations for their application in monitoring large-sized structures. Conventionally, the MEMS sensor's analog signals are converted to digital signals before radio-frequency (RF) wireless transmission. The conversion can cause a low sensitivity to the important low-frequency and low-amplitude signals. To overcome this difficulty, the authors have developed a MEMS accelerometer system, which converts the sensor output voltage to a frequency-modulated signal before RF transmission. This is achieved by using a Voltage to Frequency Conversion (V/F) instead of the conventional Analog to Digital Conversion (ADC). In this paper, a prototype MEMS accelerometer system is presented, which consists of a transmitter and receiver circuit boards. The former is equipped with a MEMS accelerometer, a V/F converter and a wireless RF transmitter, while the latter contains an RF receiver and a F/V converter for demodulating the signal. The efficacy of the MEMS accelerometer system in measuring low-frequency and low-amplitude dynamic responses is demonstrated through extensive laboratory tests and experiments on a flow-loop pipeline. PMID:25198003

Image Registration-Based Bolt Loosening Detection of Steel Joints

PubMed Central

2018-01-01

Self-loosening of bolts caused by repetitive loads and vibrations is one of the common defects that can weaken the structural integrity of bolted steel joints in civil structures. Many existing approaches for detecting loosening bolts are based on physical sensors and, hence, require extensive sensor deployment, which limit their abilities to cost-effectively detect loosened bolts in a large number of steel joints. Recently, computer vision-based structural health monitoring (SHM) technologies have demonstrated great potential for damage detection due to the benefits of being low cost, easy to deploy, and contactless. In this study, we propose a vision-based non-contact bolt loosening detection method that uses a consumer-grade digital camera. Two images of the monitored steel joint are first collected during different inspection periods and then aligned through two image registration processes. If the bolt experiences rotation between inspections, it will introduce differential features in the registration errors, serving as a good indicator for bolt loosening detection. The performance and robustness of this approach have been validated through a series of experimental investigations using three laboratory setups including a gusset plate on a cross frame, a column flange, and a girder web. The bolt loosening detection results are presented for easy interpretation such that informed decisions can be made about the detected loosened bolts. PMID:29597264

Development of a High-Sensitivity Wireless Accelerometer for Structural Health Monitoring

PubMed Central

Zhu, Li; Fu, Yuguang; Chow, Raymond; Spencer, Billie F.; Park, Jong Woong; Mechitov, Kirill

2018-01-01

Structural health monitoring (SHM) is playing an increasingly important role in ensuring the safety of structures. A shift of SHM research away from traditional wired methods toward the use of wireless smart sensors (WSS) has been motivated by the attractive features of wireless smart sensor networks (WSSN). The progress achieved in Micro Electro-Mechanical System (MEMS) technologies and wireless data transmission, has extended the effectiveness and range of applicability of WSSNs. One of the most common sensors employed in SHM strategies is the accelerometer; however, most accelerometers in WSS nodes have inadequate resolution for measurement of the typical accelerations found in many SHM applications. In this study, a high-resolution and low-noise tri-axial digital MEMS accelerometer is incorporated in a next-generation WSS platform, the Xnode. In addition to meeting the acceleration sensing demands of large-scale civil infrastructure applications, this new WSS node provides powerful hardware and a robust software framework to enable edge computing that can deliver actionable information. Hardware and software integration challenges are presented, and the associate resolutions are discussed. The performance of the wireless accelerometer is demonstrated experimentally through comparison with high-sensitivity wired accelerometers. This new high-sensitivity wireless accelerometer will extend the use of WSSN to a broader class of SHM applications. PMID:29342102

Development of a High-Sensitivity Wireless Accelerometer for Structural Health Monitoring.

PubMed

Zhu, Li; Fu, Yuguang; Chow, Raymond; Spencer, Billie F; Park, Jong Woong; Mechitov, Kirill

2018-01-17

Structural health monitoring (SHM) is playing an increasingly important role in ensuring the safety of structures. A shift of SHM research away from traditional wired methods toward the use of wireless smart sensors (WSS) has been motivated by the attractive features of wireless smart sensor networks (WSSN). The progress achieved in Micro Electro-Mechanical System (MEMS) technologies and wireless data transmission, has extended the effectiveness and range of applicability of WSSNs. One of the most common sensors employed in SHM strategies is the accelerometer; however, most accelerometers in WSS nodes have inadequate resolution for measurement of the typical accelerations found in many SHM applications. In this study, a high-resolution and low-noise tri-axial digital MEMS accelerometer is incorporated in a next-generation WSS platform, the Xnode. In addition to meeting the acceleration sensing demands of large-scale civil infrastructure applications, this new WSS node provides powerful hardware and a robust software framework to enable edge computing that can deliver actionable information. Hardware and software integration challenges are presented, and the associate resolutions are discussed. The performance of the wireless accelerometer is demonstrated experimentally through comparison with high-sensitivity wired accelerometers. This new high-sensitivity wireless accelerometer will extend the use of WSSN to a broader class of SHM applications.

Image Registration-Based Bolt Loosening Detection of Steel Joints.

PubMed

Kong, Xiangxiong; Li, Jian

2018-03-28

Self-loosening of bolts caused by repetitive loads and vibrations is one of the common defects that can weaken the structural integrity of bolted steel joints in civil structures. Many existing approaches for detecting loosening bolts are based on physical sensors and, hence, require extensive sensor deployment, which limit their abilities to cost-effectively detect loosened bolts in a large number of steel joints. Recently, computer vision-based structural health monitoring (SHM) technologies have demonstrated great potential for damage detection due to the benefits of being low cost, easy to deploy, and contactless. In this study, we propose a vision-based non-contact bolt loosening detection method that uses a consumer-grade digital camera. Two images of the monitored steel joint are first collected during different inspection periods and then aligned through two image registration processes. If the bolt experiences rotation between inspections, it will introduce differential features in the registration errors, serving as a good indicator for bolt loosening detection. The performance and robustness of this approach have been validated through a series of experimental investigations using three laboratory setups including a gusset plate on a cross frame, a column flange, and a girder web. The bolt loosening detection results are presented for easy interpretation such that informed decisions can be made about the detected loosened bolts.

Feasibility of frequency-modulated wireless transmission for a multi-purpose MEMS-based accelerometer.

PubMed

Sabato, Alessandro; Feng, Maria Q

2014-09-05

Recent advances in the Micro Electro-Mechanical System (MEMS) technology have made wireless MEMS accelerometers an attractive tool for Structural Health Monitoring (SHM) of civil engineering structures. To date, sensors' low sensitivity and accuracy--especially at very low frequencies--have imposed serious limitations for their application in monitoring large-sized structures. Conventionally, the MEMS sensor's analog signals are converted to digital signals before radio-frequency (RF) wireless transmission. The conversion can cause a low sensitivity to the important low-frequency and low-amplitude signals. To overcome this difficulty, the authors have developed a MEMS accelerometer system, which converts the sensor output voltage to a frequency-modulated signal before RF transmission. This is achieved by using a Voltage to Frequency Conversion (V/F) instead of the conventional Analog to Digital Conversion (ADC). In this paper, a prototype MEMS accelerometer system is presented, which consists of a transmitter and receiver circuit boards. The former is equipped with a MEMS accelerometer, a V/F converter and a wireless RF transmitter, while the latter contains an RF receiver and a F/V converter for demodulating the signal. The efficacy of the MEMS accelerometer system in measuring low-frequency and low-amplitude dynamic responses is demonstrated through extensive laboratory tests and experiments on a flow-loop pipeline.

NASA technology program for future civil air transports

NASA Technical Reports Server (NTRS)

Wright, H. T.

1983-01-01

An assessment is undertaken of the development status of technology, applicable to future civil air transport design, which is currently undergoing conceptual study or testing at NASA facilities. The NASA civil air transport effort emphasizes advanced aerodynamic computational capabilities, fuel-efficient engines, advanced turboprops, composite primary structure materials, advanced aerodynamic concepts in boundary layer laminarization and aircraft configuration, refined control, guidance and flight management systems, and the integration of all these design elements into optimal systems. Attention is given to such novel transport aircraft design concepts as forward swept wings, twin fuselages, sandwich composite structures, and swept blade propfans.

Identification of modal strains using sub-microstrain FBG data and a novel wavelength-shift detection algorithm

NASA Astrophysics Data System (ADS)

Anastasopoulos, Dimitrios; Moretti, Patrizia; Geernaert, Thomas; De Pauw, Ben; Nawrot, Urszula; De Roeck, Guido; Berghmans, Francis; Reynders, Edwin

2017-03-01

The presence of damage in a civil structure alters its stiffness and consequently its modal characteristics. The identification of these changes can provide engineers with useful information about the condition of a structure and constitutes the basic principle of the vibration-based structural health monitoring. While eigenfrequencies and mode shapes are the most commonly monitored modal characteristics, their sensitivity to structural damage may be low relative to their sensitivity to environmental influences. Modal strains or curvatures could offer an attractive alternative but current measurement techniques encounter difficulties in capturing the very small strain (sub-microstrain) levels occurring during ambient, or operational excitation, with sufficient accuracy. This paper investigates the ability to obtain sub-microstrain accuracy with standard fiber-optic Bragg gratings using a novel optical signal processing algorithm that identifies the wavelength shift with high accuracy and precision. The novel technique is validated in an extensive experimental modal analysis test on a steel I-beam which is instrumented with FBG sensors at its top and bottom flange. The raw wavelength FBG data are processed into strain values using both a novel correlation-based processing technique and a conventional peak tracking technique. Subsequently, the strain time series are used for identifying the beam's modal characteristics. Finally, the accuracy of both algorithms in identification of modal characteristics is extensively investigated.

47 CFR 24.243 - The cost-sharing formula.

Code of Federal Regulations, 2010 CFR

2010-10-01

...; monitoring or control equipment; engineering costs (design/path survey); installation; systems testing; FCC filing costs; site acquisition and civil works; zoning costs; training; disposal of old equipment; test...

Comparison of fundamental natural period of masonry and reinforced concrete buildings retrieved from experimental campaigns performed in Italy, Greece and Spain

NASA Astrophysics Data System (ADS)

Nigro, Antonella; Ponzo, Felice C.; Ditommaso, Rocco; Auletta, Gianluca; Iacovino, Chiara; Nigro, Domenico S.; Soupios, Pantelis; García-Fernández, Mariano; Jimenez, Maria-Jose

2017-04-01

Aim of this study is the experimental estimation of the dynamic characteristics of existing buildings and the comparison of the related fundamental natural period of the buildings (masonry and reinforced concrete) located in Basilicata (Italy), in Madrid (Spain) and in Crete (Greece). Several experimental campaigns, on different kind of structures all over the world, have been performed in the last years with the aim of proposing simplified relationships to evaluate the fundamental period of buildings. Most of formulas retrieved from experimental analyses provide vibration periods smaller than those suggested by the Italian Seismic Code (NTC2008) and the European Seismic Code (EC8). It is known that the fundamental period of a structure play a key role in the correct estimation of the spectral acceleration for seismic static analyses and to detect possible resonance phenomena with the foundation soil. Usually, simplified approaches dictate the use of safety factors greater than those related to in depth dynamic linear and nonlinear analyses with the aim to cover any unexpected uncertainties. The fundamental period calculated with the simplified formula given by both NTC 2008 and EC8 is higher than the fundamental period measured on the investigated structures in Italy, Spain and Greece. The consequence is that the spectral acceleration adopted in the seismic static analysis may be significantly different than real spectral acceleration. This approach could produces a decreasing in safety factors obtained using linear seismic static analyses. Based on numerical and experimental results, in order to confirm the results proposed in this work, authors suggest to increase the number of numerical and experimental tests considering also the effects of non-structural components and soil during small, medium and strong motion earthquakes. Acknowledgements This study was partially funded by the Italian Department of Civil Protection within the project DPC-RELUIS 2016 - RS4 ''Seismic observatory of structures and health monitoring'' and by the "Centre of Integrated Geomorphology for the Mediterranean Area - CGIAM" within the Framework Agreement with the University of Basilicata "Study, Research and Experimentation in the Field of Analysis and Monitoring of Seismic Vulnerability of Strategic and Relevant Buildings for the purposes of Civil Protection and Development of Innovative Strategies of Seismic Reinforcement".

30 CFR 250.1497 - When will BOEMRE monitor my financial solvency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false When will BOEMRE monitor my financial solvency? 250.1497 Section 250.1497 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Civil Penaltie...

Monitoring the ongoing deformation and seasonal behaviour affecting Mosul Dam through space-borne SAR data

NASA Astrophysics Data System (ADS)

Tessari, G.; Riccardi, P.; Pasquali, P.

2017-12-01

Monitoring of dam structural health is an important practice to control the structure itself and the water reservoir, to guarantee efficient operation and safety of surrounding areas. Ensuring the longevity of the structure requires the timely detection of any behaviour that could deteriorate the dam and potentially result in its shutdown or failure.The detection and monitoring of surface displacements is increasingly performed through the analysis of satellite Synthetic Aperture Radar (SAR) data, thanks to the non-invasiveness of their acquisition, the possibility to cover large areas in a short time and the new space missions equipped with high spatial resolution sensors. The availability of SAR satellite acquisitions from the early 1990s enables to reconstruct the historical evolution of dam behaviour, defining its key parameters, possibly from its construction to the present. Furthermore, the progress on SAR Interferometry (InSAR) techniques through the development of Differential InSAR (DInSAR) and Advanced stacking techniques (A-DInSAR) allows to obtain accurate velocity maps and displacement time-series.The importance of these techniques emerges when environmental or logistic conditions do not allow to monitor dams applying the traditional geodetic techniques. In such cases, A-DInSAR constitutes a reliable diagnostic tool of dam structural health to avoid any extraordinary failure that may lead to loss of lives.In this contest, an emblematic case will be analysed as test case: the Mosul Dam, the largest Iraqi dam, where monitoring and maintaining are impeded for political controversy, causing possible risks for the population security. In fact, it is considered one of the most dangerous dams in the world because of the erosion of the gypsum rock at the basement and the difficult interventions due to security problems. The dam consists of 113 m tall and 3.4 km long earth-fill embankment-type, with a clay core, and it was completed in 1984.The deformation fields obtained from SAR data are evaluated to assess the temporal evolution of the strains affecting the structure. Obtained results represent the preliminary stage of a multidisciplinary project, finalized to assess possible damages affecting a dam through remote sensing and civil engineering surveys.

Ground Penetrating Radar for SMART CITIES

NASA Astrophysics Data System (ADS)

Soldovieri, Francesco; Catapano, Ilaria; Gennarelli, Gianluca

2016-04-01

The use of monitoring and surveillance technologies is now recognized as a reliable option of the overall smart cities management cycle, for the advantages that they offer in terms of: economically sustainable planning of the ordinary and extraordinary maintenance interventions; situational awareness of possible risks factors in view of a reliable early warning; improvement of the security of the communities especially in public environments. In this frame, the abstract will deal with the recent advances in the development and deployment of radar systems for the urban surveillance, exploitation of the subsurface resources and civil engineering structures. In particular, we will present the recent scientific developments and several examples of use of these systems in operational conditions.

Do Canadian Civil Servants Care About the Health of Populations?

PubMed Central

Lavis, John N.; Ross, Suzanne E.; Stoddart, Gregory L.; Hohenadel, Joanne M.; McLeod, Christopher B.; Evans, Robert G.

2003-01-01

Objectives. This article describes Canadian civil servants’ awareness of, attitudes toward, and self-reported use of ideas about the determinants of health. Methods. Federal and provincial civil servants in departments of finance, labor, social services, and health were surveyed. Results. With civil servants in finance departments a notable exception, most Canadian civil servants see the health of populations as a relevant outcome for their sectors. Many (65%) report that ideas about the determinants of health have already influenced policymaking in their sector, but most (83%) say they need more information about the health consequences of the policy alternatives their departments face. Conclusions. Civil servants should consider developing accountability structures for health and researchers should consider producing and transferring more policy-relevant research. PMID:12660214

Nurturing the H in HR: Using Action Learning to Build Organisation Development Capability in the UK Civil Service

ERIC Educational Resources Information Center

Hale, Richard; Saville, Martin

2014-01-01

In the UK, the Civil Service Reform Plan is being implemented with urgency. This requires Civil Service departments and agencies to reform their structures and ways of working in order to deliver effective services in a climate of economic austerity and rapid social and technological change. Historically, Human Resource (HR) professionals have…

A new method to assess damage to RCMRFs from period elongation and Park-Ang damage index using IDA

NASA Astrophysics Data System (ADS)

Aghagholizadeh, Mehrdad; Massumi, Ali

2016-09-01

Despite a significant progress in loading and design codes of seismic resistant structures and technology improvements in building structures, the field of civil engineering is still facing critical challenges. An example of those challenges is the assessment of the state of damage that has been imposed to a structure after earthquakes of different intensities. To determine the operability of a structure and its resistance to probable future earthquakes, quick assessment of damages and determining the operability of a structure after an earthquake are crucial. Present methods to calculate damage to structures are time consuming and do not accurately provide the rate of damage. Damage estimation is important task in the fields of structural health monitoring and decision-making. This study examines the relationship between period elongation and the Park-Ang damage index. A dynamic non-linear analysis is employed with IDARC program to calculate the amount of damage and period of the current state. This new method is shown to be a quick and accurate technique for damage assessment. It is easy to calculate the period of an existing structure and changes in the period which reflects changes in the stiffness matrix.

The Emergence of Cambodian Civil Society within Global Educational Governance: A Morphogenetic Approach to Agency and Structure

ERIC Educational Resources Information Center

Edwards, D. Brent, Jr.; Brehm, William C.

2015-01-01

This paper uses Margaret Archer's morphogenetic approach to analyze the emergence of civil society within global educational governance. The purpose is to understand the intersection of historical structures with global actors and spaces that have accompanied the globalization of education. Based on findings from a study on the impact in Cambodia…

Opportunities and challenges for structural health monitoring of radioactive waste systems and structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giurgiutiu, Victor; Mendez Torres, Adrian E.

2013-07-01

Radioactive waste systems and structures (RWSS) are safety-critical facilities in need of monitoring over prolonged periods of time. Structural health monitoring (SHM) is an emerging technology that aims at monitoring the state of a structure through the use of networks of permanently mounted sensors. SHM technologies have been developed primarily within the aerospace and civil engineering communities. This paper addresses the issue of transitioning the SHM concept to the monitoring of RWSS and evaluates the opportunities and challenges associated with this process. Guided wave SHM technologies utilizing structurally-mounted piezoelectric wafer active sensors (PWAS) have a wide range of applications basedmore » on both propagating-wave and standing-wave methodologies. Hence, opportunities exist for transitioning these SHM technologies into RWSS monitoring. However, there exist certain special operational conditions specific to RWSS such as: radiation field, caustic environments, marine environments, and chemical, mechanical and thermal stressors. In order to address the high discharge of used nuclear fuel (UNF) and the limited space in the storage pools the U.S. the Department of Energy (DOE) has adopted a 'Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste' (January 2013). This strategy endorses the key principles that underpin the Blue Ribbon Commission's on America's Nuclear Future recommendations to develop a sustainable program for deploying an integrated system capable of transporting, storing, and disposing of UNF and high-level radioactive waste from civilian nuclear power generation, defense, national security, and other activities. This will require research to develop monitoring, diagnosis, and prognosis tools that can aid to establish a strong technical basis for extended storage and transportation of UNF. Monitoring of such structures is critical for assuring the safety and security of the nation's spent nuclear fuel until a national policy for closure of the nuclear fuel cycle is defined and implemented. In addition, such tools can provide invaluable and timely information for verification of the predicted mechanical performance of RWSS (e.g. concrete or steel barriers) during off-normal occurrence and accident events such as the tsunami and earthquake event that affected Fukushima Daiichi nuclear power plant. The ability to verify the conditions, health, and degradation behavior of RWSS over time by applying nondestructive testing (NDT) as well as development of nondestructive evaluation (NDE) tools for new degradation processes will become challenging. The paper discusses some of the challenges associated to verification and diagnosis for RWSS and identifies SHM technologies which are more readily available for transitioning into RWSS applications. Fundamental research objectives that should be considered for the transition of SHM technologies (e.g., radiation hardened piezoelectric materials) for RWSS applications are discussed. The paper ends with summary, conclusions, and suggestions for further work. (authors)« less

Self-stress control of real civil engineering tensegrity structures

NASA Astrophysics Data System (ADS)

Kłosowska, Joanna; Obara, Paulina; Gilewski, Wojciech

2018-01-01

The paper introduces the impact of the self-stress level on the behaviour of the tensegrity truss structures. Displacements for real civil engineering tensegrity structures are analysed. Full-scale tensegrity tower Warnow Tower which consists of six Simplex trusses is considered in this paper. Three models consisting of one, two and six modules are analysed. The analysis is performed by the second and third order theory. Mathematica software and Sofistik programme is applied to the analysis.

Passive monitoring using traffic noise recordings - case study on the Steinachtal Bridge

NASA Astrophysics Data System (ADS)

Salvermoser, Johannes; Stähler, Simon; Hadziioannou, Céline

2015-04-01

Civil structures age continuously. The early recognition of potentially critical damages is an important economical issue, but also one of public safety. Continuous tracking of small changes in the medium by using passive methods would offer an extension to established active non-destructive testing procedures at relatively low cost. Here we present a case study of structural monitoring using continuous recordings of traffic noise on a 200 meter long reinforced concrete highway bridge in Germany. Over two months of continuos geophone records are used in the frequency range of 2-8 Hz. Using passive image interferometry, evaluation of hourly cross-correlations between recordings at pairs of receivers yield velocity variations in the range of -1.5% to +2.1%. We were able to correlate our outcomes with temperature measurements of the same two month period. The measured velocity changes scale with the temperature variations with on average a dv/v of 0.064% per degree Celsius. This value is in accordance with other studies of concrete response to temperature, confirming that we are able to observe subtle changes with physical origin. It is shown that traffic noise is temporally homogenenous enough to fulfill the requirements of passive image interferometry.

Identification of unusual events in multichannel bridge monitoring data using wavelet transform and outlier analysis

NASA Astrophysics Data System (ADS)

Omenzetter, Piotr; Brownjohn, James M. W.; Moyo, Pilate

2003-08-01

Continuously operating instrumented structural health monitoring (SHM) systems are becoming a practical alternative to replace visual inspection for assessment of condition and soundness of civil infrastructure. However, converting large amount of data from an SHM system into usable information is a great challenge to which special signal processing techniques must be applied. This study is devoted to identification of abrupt, anomalous and potentially onerous events in the time histories of static, hourly sampled strains recorded by a multi-sensor SHM system installed in a major bridge structure in Singapore and operating continuously for a long time. Such events may result, among other causes, from sudden settlement of foundation, ground movement, excessive traffic load or failure of post-tensioning cables. A method of outlier detection in multivariate data has been applied to the problem of finding and localizing sudden events in the strain data. For sharp discrimination of abrupt strain changes from slowly varying ones wavelet transform has been used. The proposed method has been successfully tested using known events recorded during construction of the bridge, and later effectively used for detection of anomalous post-construction events.

Broken rail track detection using smart materials

NASA Astrophysics Data System (ADS)

Bouteiller, Fanny; Grisso, Benjamin L.; Peairs, Daniel M.; Inman, Daniel J.

2006-03-01

Rail lines are subject to many types of damage that, in the worst cases, can cause train derailments. The damage can arise from either manufacturing defects or external factors, possibly even terrorist acts to disrupt the civil infrastructure. Current rail inspection techniques require train traffic to be interrupted while workers and equipment move along the track. Moreover, a technician with rail testing experience is required to analyze the results. This paper focuses on simple proof of concept experiments to determine if impedance based structural health monitoring may be used to detect anomalies in rail tracks, and in particular broken rails. The technique applies a very low voltage (one volt) high frequency wave to a structure, measures its response and determines the location and extent of a rail break. The monitoring device is envisioned to run off of ambient vibration and thermal gradients provided by passing trains and daily thermal cycles, store the energy and utilize the stored energy periodically to inspect the track (according to the track usage schedule). If damage occurs or starts to occur, a warning signal would be transmitted to substation then broadcast to the appropriate operator listing the location and extent of the damage.

Performance Monitoring of a Nearshore Berm at Ft. Myers Beach, Florida

DTIC Science & Technology

2013-08-01

prototype designs. Coastal Zone ’93, American Society of Civil Engineers, pp. 2938 -2950. Andrassy, C . J. 1991. Monitoring of a nearshore disposal mound at...ER D C / CH L TR -1 3 -1 1 Performance Monitoring of a Nearshore Berm at Ft. Myers Beach, Florida: Final Report C oa st al a n d H yd...122  Appendix C : USF-CRL Survey Data: morphologic evolution during the first 2 years post construction

An example of requirements for Advanced Subsonic Civil Transport (ASCT) flight control system using structured techniques

NASA Technical Reports Server (NTRS)

Mclees, Robert E.; Cohen, Gerald C.

1991-01-01

The requirements are presented for an Advanced Subsonic Civil Transport (ASCT) flight control system generated using structured techniques. The requirements definition starts from initially performing a mission analysis to identify the high level control system requirements and functions necessary to satisfy the mission flight. The result of the study is an example set of control system requirements partially represented using a derivative of Yourdon's structured techniques. Also provided is a research focus for studying structured design methodologies and in particular design-for-validation philosophies.

MINERVA: An INSAR Monitoring Service for Volcanic Hazard

NASA Astrophysics Data System (ADS)

Tampellini, M. L.; Sansosti, E.; Usai, S.; Lanari, R.; Borgstrom, S.; van Persie, M.; Ricciardi, G. P.; Maddalena, V.; Cicero, L.; Pepe, A.

2004-06-01

MINERVA (Monitoring by Interferometric SAR of Environmental Risk in Volcanic Areas) is a small scale service demonstration project financed by ESA in the Data User Programme framework. The objective of the project is the design, development and assessment of a demonstrative information service based on the interferometric processing of images acquired from either the ASAR instrument on board ENVISAT-I or SAR instruments on board ERS1/2. The system is based on a new approach for the processing of INSAR data, which allows to optimize the quality of interferograms spanning from 35 days up to several years, and to merge them to generate a single solution describing the temporal evolution of the ground deformations in the examined risk area. The system allows to update this solution each time a new SAR image is available, and constitutes therefore an innovative tool for monitoring of the ground displacements in risk areas. The system has been implemented and demonstrated at Osservatorio Vesuviano (Naples, Italy), which is the institution responsible for monitoring the volcanic phenomena in the Neapolitan volcanic district, and for alerting the Italian civil authorities (''Protezione Civile'') in case such monitoring activity reveals signals of imminent eruptions. In particular, the MINERVA system has been used to monitor the ground deformations at the Phlegrean Fields, a densely populated, high-hazard zone which is subject to alternate phases of uplift and subsidence, accompanied often by seismic activity.

Engineer at Lehigh University Campaigns for More Construction Research.

ERIC Educational Resources Information Center

Wheeler, David L.

1987-01-01

A civil engineering professor would like to see civil engineers spend less time looking at broken structures and more time testing construction materials, and has founded a research center for that purpose. (MSE)

Photocopy of plan (in collection of U.S. Coast Guard Civil ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of plan (in collection of U.S. Coast Guard Civil Engineering Unit Providence, Warwick, RI), U.S. Coast Guard Civil Engineering, third district, marine railway, Sandy Hook Station, Ft. Hancock, Sandy Hook, NJ, repairs, plan sections & framing details, wharf B - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

Monitoring localized cracks on under pressure concrete nuclear containment wall using linear and nonlinear ultrasonic coda wave interferometry

NASA Astrophysics Data System (ADS)

Legland, J.-B.; Abraham, O.; Durand, O.; Henault, J.-M.

2018-04-01

Civil engineering is constantly demanding new methods for evaluation and non-destructive testing (NDT), particularly to prevent and monitor serious damage to concrete structures. Tn this work, experimental results are presented on the detection and characterization of cracks using nonlinear modulation of coda waves interferometry (NCWT) [1]. This method consists in mixing high-amplitude low-frequency acoustic waves with multi-scattered probe waves (coda) and analyzing their effects by interferometry. Unlike the classic method of coda analysis (CWT), the NCWT does not require the recording of a coda as a reference before damage to the structure. Tn the framework of the PTA-ENDE project, a 1/3 model of a preconstrained concrete containment (EDF VeRCoRs mock-up) is placed under pressure to study the leakage of the structure. During this evaluation protocol, specific areas are monitored by the NCWT (during 5 days, which correspond to the protocol of nuclear power plant pressurization under maintenance test). The acoustic nonlinear response due to the high amplitude of the acoustic modulation gives pertinent information about the elastic and dissipative nonlinearities of the concrete. Tts effective level is evaluated by two nonlinear observables extracted from the interferometry. The increase of nonlinearities is in agreement with the creation of a crack with a network of microcracks located at its base; however, a change in the dynamics of the evolution of the nonlinearities may indicate the opening of a through crack. Tn addition, as during the experimental campaign, reference codas have been recorded. We used CWT to follow the stress evolution and the gas leaks ratio of the structure. Both CWT and NCWT results are presented in this paper.

A new type of smart basalt fiber-reinforced polymer bars as both reinforcements and sensors for civil engineering application

NASA Astrophysics Data System (ADS)

Tang, Yongsheng; Wu, Zhishen; Yang, Caiqian; Wu, Gang; Shen, Sheng

2010-11-01

In this paper, a new type of smart basalt fiber-reinforced polymer (BFRP) bar is developed and their sensing performance is investigated by using the Brillouin scattering-based distributed fiber optic sensing technique. The industrial manufacturing process is first addressed, followed by an experimental study on the strain, temperature and fundamental mechanical properties of the BFRP bars. The results confirm the superior sensing properties, in particular the measuring accuracy, repeatability and linearity through comparing with bare optical fibers. Results on the mechanical properties show stable elastic modulus and high ultimate strength. Therefore, the smart BFRP bar has potential applications for long-term structural health monitoring (SHM) as embedded sensors as well as strengthening and upgrading structures. Moreover the coefficient of thermal expansion for smart BFRP bars is similar to the value for concrete.

75 FR 42087 - Science Advisory Board Staff Office; Request for Nominations of Experts for the SAB Hydraulic...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

... regarding trace organics and environmental monitoring; statistics, particularly regarding experimental design of field studies; human health effects and risk assessment; civil and environmental engineering...

Civil infrastructure monitoring for IVHS using optical fiber sensors

NASA Astrophysics Data System (ADS)

de Vries, Marten J.; Arya, Vivek; Grinder, C. R.; Murphy, Kent A.; Claus, Richard O.

1995-01-01

8Early deployment of Intelligent Vehicle Highway Systems would necessitate the internal instrumentation of infrastructure for emergency preparedness. Existing quantitative analysis and visual analysis techniques are time consuming, cost prohibitive, and are often unreliable. Fiber optic sensors are rapidly replacing conventional instrumentation because of their small size, light weight, immunity to electromagnetic interference, and extremely high information carrying capability. In this paper research on novel optical fiber sensing techniques for health monitoring of civil infrastructure such as highways and bridges is reported. Design, fabrication, and implementation of fiber optic sensor configurations used for measurements of strain are discussed. Results from field tests conducted to demonstrate the effectiveness of fiber sensors at determining quantitative strain vector components near crack locations in bridges are presented. Emerging applications of fiber sensors for vehicle flow, vehicle speed, and weigh-in-motion measurements are also discussed.

Cold Vacuum Drying facility civil structural system design description (SYS 06)

DOE Office of Scientific and Technical Information (OSTI.GOV)

PITKOFF, C.C.

This document describes the Cold Vacuum Drying (CVD) Facility civil - structural system. This system consists of the facility structure, including the administrative and process areas. The system's primary purpose is to provide for a facility to house the CVD process and personnel and to provide a tertiary level of containment. The document provides a description of the facility and demonstrates how the design meets the various requirements imposed by the safety analysis report and the design requirements document.

Evolving Hazard Monitoring and Communication at San Vicente Volcano, El Salvador

NASA Astrophysics Data System (ADS)

Bowman, L. J.; Gierke, J. S.

2014-12-01

El Salvador has 20 potentially active volcanoes, four of which have erupted in the last 100 years. Since San Vicente Volcano has had no historic eruptions, monitoring is not a high priority; especially given the current eruptive crisis at San Miguel Volcano. Though probability of eruptive hazards remains low at San Vicente, it is arguably one of the most hazardous volcanoes in the country due to rainfall-induced landslides and debris-flow risk. At least 250 deaths occurred in November 2009 from landslides and debris flows triggered by Hurricane Ida. This disaster caused the Universidad de El Salvador - Facultad Multidisciplinaria Paracentral (UES-FMP, San Vicente, El Salvador) to partner with governmental and nongovernmental organizations (including the U.S. Peace Corps, U.S. Fulbright Program, Korean International Cooperation Agency, Protección Civil and the Centro de Protección para Desastres (CEPRODE)) to focus its faculty and student research toward hazard monitoring and risk studies. Newly established monitoring efforts include: measurement of surface cracks and localized rainfall by Protección Civil and local residents using crude extensometers and rain gauges; installation of six weather stations that operate within the most at-risk municipalities; seismic refraction surveys to better characterize stratigraphy and seasonal water table changes; and most recently, a USAID/NSF-funded initiative partnered with the UES-FMP to monitor seasonal hydrologic conditions related to flooding and groundwater recharge. The information from these initiatives is now used to communicate current conditions and warnings through a network of two-way radios established by CEPRODE and Protección Civil. Representatives from the multi-institutional team also communicate the data to authorities who make better-informed decisions regarding warnings and evacuations, as well as determine suitable areas for population relocation in the event of a crisis. Data will eventually be used to model and forecast potential hazard events.

Impact resonance method for damage detection in RC beams strengthened with composites

NASA Astrophysics Data System (ADS)

Gheorghiu, Catalin; Rhazi, Jamal E.; Labossiere, Pierre

2005-05-01

There are numerous successful applications of fibre-reinforced composites for strengthening the civil engineering infrastructure. Most of these repairs are being continuously or intermittently monitored for assessing their effectiveness and safety. The impact resonance method (IRM), a non-destructive technique, utilized in civil engineering exclusively for determining the dynamic concrete properties, could be a valuable and viable damage detection tool for structural elements. The IRM gives useful information about the dynamic characteristics of rectangular and circular concrete members such as beams and columns. In this experimental program, a 1.2-m-long reinforced concrete beam strengthened with a carbon fibre-reinforced polymer (CFRP) plate has been employed. The CFRP-strengthened beam has been loaded in fatigue for two million cycles at 3 Hz. The load amplitude was from 15 to 35% of the anticipated yielding load of the beam. Throughout fatigue testing the cycling was stopped for IRM measurements to be taken. The obtained data provided information about changes in modal properties such as natural frequencies of vibration. These results have shown the successful use of the IRM for detecting fatigue damage in concrete members strengthened with composites.

Baseline Assessment and Prioritization Framework for IVHM Integrity Assurance Enabling Capabilities

NASA Technical Reports Server (NTRS)

Cooper, Eric G.; DiVito, Benedetto L.; Jacklin, Stephen A.; Miner, Paul S.

2009-01-01

Fundamental to vehicle health management is the deployment of systems incorporating advanced technologies for predicting and detecting anomalous conditions in highly complex and integrated environments. Integrated structural integrity health monitoring, statistical algorithms for detection, estimation, prediction, and fusion, and diagnosis supporting adaptive control are examples of advanced technologies that present considerable verification and validation challenges. These systems necessitate interactions between physical and software-based systems that are highly networked with sensing and actuation subsystems, and incorporate technologies that are, in many respects, different from those employed in civil aviation today. A formidable barrier to deploying these advanced technologies in civil aviation is the lack of enabling verification and validation tools, methods, and technologies. The development of new verification and validation capabilities will not only enable the fielding of advanced vehicle health management systems, but will also provide new assurance capabilities for verification and validation of current generation aviation software which has been implicated in anomalous in-flight behavior. This paper describes the research focused on enabling capabilities for verification and validation underway within NASA s Integrated Vehicle Health Management project, discusses the state of the art of these capabilities, and includes a framework for prioritizing activities.

Real time bolt preload monitoring using piezoceramic transducers and time reversal technique—a numerical study with experimental verification

NASA Astrophysics Data System (ADS)

Parvasi, Seyed Mohammad; Ho, Siu Chun Michael; Kong, Qingzhao; Mousavi, Reza; Song, Gangbing

2016-08-01

Bolted joints are ubiquitous structural elements, and form critical connections in mechanical and civil structures. As such, loosened bolted joints may lead to catastrophic failures of these structures, thus inspiring a growing interest in monitoring of bolted joints. A novel energy based wave method is proposed in this study to monitor the axial load of bolted joint connections. In this method, the time reversal technique was used to focus the energy of a piezoelectric (PZT)-generated ultrasound wave from one side of the interface to be measured as a signal peak by another PZT transducer on the other side of the interface. A tightness index (TI) was defined and used to correlate the peak amplitude to the bolt axial load. The TI bypasses the need for more complex signal processing required in other energy-based methods. A coupled, electro-mechanical analysis with elasto-plastic finite element method was used to simulate and analyze the PZT based ultrasonic wave propagation through the interface of two steel plates connected by a single nut and bolt connection. Numerical results, backed by experimental results from testing on a bolted connection between two steel plates, revealed that the peak amplitude of the focused signal increases as the bolt preload (torque level) increases due to the enlarging true contact area of the steel plates. The amplitude of the focused peak saturates and the TI reaches unity as the bolt axial load reaches a threshold value. These conditions are associated with the maximum possible true contact area between the surfaces of the bolted connection.

Miniature fiber Bragg grating sensor interrogator (FBG-Transceiver) system

NASA Astrophysics Data System (ADS)

Mendoza, Edgar A.; Kempen, Cornelia; Lopatin, Craig

2007-04-01

This paper describes recent progress conducted towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-Transceiver TM) system based on multi-channel integrated optic sensor (InOSense TM) microchip technology. The hybrid InOSense TM microchip technology enables the integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogator systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation. The FBG-Transceiver system uses active optoelectronic components monolithically integrated to the InOSense TM microchip, a microprocessor controlled signal processing electronics board capable of processing the FBG sensors signals related to stress-strain and temperature as well as vibration and acoustics. The FBG-Transceiver TM system represents a new, reliable, highly robust technology that can be used to accurately monitor the status of an array of distributed fiber optic Bragg grating sensors installed in critical infrastructures. Its miniature package, low power operation, and state-of-the-art data communications architecture, all at a very affordable price makes it a very attractive solution for a large number of SHM/NDI applications in aerospace, naval and maritime industry, civil structures like bridges, buildings and dams, the oil and chemical industry, and for homeland security applications. The miniature, cost-efficient FBG-Transceiver TM system is poised to revolutionize the field of structural health monitoring and nondestructive inspection market. The sponsor of this program is NAVAIR under a DOD SBIR contract.

Fiber Bragg grating sensors in harsh environments: considerations and industrial monitoring applications

NASA Astrophysics Data System (ADS)

Méndez, Alexis

2017-06-01

Over the last few years, fiber optic sensors (FOS) have seen an increased acceptance and widespread use in industrial sensing and in structural monitoring in civil, aerospace, marine, oil & gas, composites and other applications. One of the most prevalent types in use today are fiber Bragg grating (FBG) sensors. Historically, FOS have been an attractive solution because of their EM immunity and suitability for use in harsh environments and rugged applications with extreme temperatures, radiation exposure, EM fields, high voltages, water contact, flammable atmospheres, or other hazards. FBG sensors have demonstrated that can operate reliably in many different harsh environment applications but proper type and fabrication process are needed, along with suitable packaging and installation procedure. In this paper, we review the impact that external factors and environmental conditions play on FBG's performance and reliability, and describe the appropriate sensor types and protection requirements suitable for a variety of harsh environment applications in industrial furnaces, cryogenic coolers, nuclear plants, maritime vessels, oil & gas wells, aerospace crafts, automobiles, and others.

Capacity and readiness of civil society organisations to implement community case management of malaria in Kenya.

PubMed

Marita, Enock; Oule, Jared; Mungai, Margaret; Thiam, Sylla; Ilako, Festus

2016-01-01

Civil Society Organizations (CSOs) contribute to achieving development goals through advocacy, social mobilisation and provision of health services. CSO programming is a key component of Global Fund (GF) grants; however, CSOs face technical and governance capacity challenges in grant utilisation leading to missed opportunities for improving health at community level. Amref Health Africa was appointed Principal Recipient of a GF grant aimed at scaling up community case management of malaria through CSOs as sub-recipients in western Kenya. To identify potential risks and strengthen grant management, Amref Health Africa and the Ministry of Health conducted a capacity needs assessment to determine the capacity of CSOs to effectively utilise grants. 26 selected CSOs participated in this study. Document reviews and on-site assessments and observations were conducted using structured tool. The five main assessment areas were: governance and risk management; strategic and operational planning; monitoring and evaluation; programme management; and financial management. Overall performance was grouped into four categories: 3.0-2.5 (excellent), 2.0-2.4 (good), 1.5-1.9 (fair), and 1.0-1.4 (poor). Data were collected and analysed using Excel software. Twenty five out of 26 CSOs were legally compliant. 14(54%) CSOs were categorized as good; 7(27%) as excellent; 3(12%) as poor and 2(8%) as fair. Most CSOs had good programme management capacity but monitoring and evaluation presented the most capacity gaps. More than 75% of the CSOs were rated as excellent or good. A capacity building plan, programme risk management plan and oversight mechanisms were important for successful grant implementation.

A multi-disciplinary approach for the structural monitoring of Cultural Heritages in a seismic area

NASA Astrophysics Data System (ADS)

Fabrizia Buongiorno, Maria; Musacchio, Massimo; Guerra, Ignazio; Porco, Giacinto; Stramondo, Salvatore; Casula, Giuseppe; Caserta, Arrigo; Speranza, Fabio; Doumaz, Fawzi; Giovanna Bianchi, Maria; Luzi, Guido; Ilaria Pannaccione Apa, Maria; Montuori, Antonio; Gaudiosi, Iolanda; Vecchio, Antonio; Gervasi, Anna; Bonali, Elena; Romano, Dolores; Falcone, Sergio; La Piana, Carmelo

2014-05-01

In the recent years, the concepts of seismic risk vulnerability and structural health monitoring have become very important topics in the field of both structural and civil engineering for the identification of appropriate risk indicators and risk assessment methodologies in Cultural Heritages monitoring. The latter, which includes objects, building and sites with historical, architectural and/or engineering relevance, concerns the management, the preservation and the maintenance of the heritages within their surrounding environmental context, in response to climate changes and natural hazards (e.g. seismic, volcanic, landslides and flooding hazards). Within such a framework, the complexity and the great number of variables to be considered require a multi-disciplinary approach including strategies, methodologies and tools able to provide an effective monitoring of Cultural Heritages form both scientific and operational viewpoints. Based on this rationale, in this study, an advanced, technological and operationally-oriented approach is presented and tested, which enables measuring and monitoring Cultural Heritage conservation state and geophysical/geological setting of the area, in order to mitigate the seismic risk of the historical public goods at different spatial scales*. The integration between classical geophysical methods with new emerging sensing techniques enables a multi-depth, multi-resolution, and multi-scale monitoring in both space and time. An integrated system of methodologies, instrumentation and data-processing approaches for non-destructive Cultural Heritage investigations is proposed, which concerns, in detail, the analysis of seismogenetic sources, the geological-geotechnical setting of the area and site seismic effects evaluation, proximal remote sensing techniques (e.g. terrestrial laser scanner, ground-based radar systems, thermal cameras), high-resolution aerial and satellite-based remote sensing methodologies (e.g. aeromagnetic surveys, synthetic aperture radar, optical, multispectral and panchromatic measurements), static and dynamic structural health monitoring analysis (e.g. screening tests with georadar, sonic instruments, sclerometers and optic fibers). The final purpose of the proposed approach is the development of an investigation methodology for short- and long-term Cultural Heritages preservation in response to seismic stress, which has specific features of scalability, modularity and exportability for every possible monitoring configuration. Moreover, it allows gathering useful information to furnish guidelines for Institution and local Administration to plan consolidation actions and therefore prevention activity. Some preliminary results will be presented for the test site of Calabria Region, where some architectural heritages have been properly selected as case studies for monitoring purposes. *The present work is supported and funded by Ministero dell'Università, dell'Istruzione e della Ricerca (MIUR) under the research project PON01-02710 "MASSIMO" - "Monitoraggio in Area Sismica di Sistemi Monumentali".

Multiplexing Technology for Acoustic Emission Monitoring of Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Prosser, William; Percy, Daniel

2003-01-01

The initiation and propagation of damage mechanisms such as cracks and delaminations generate acoustic waves, which propagate through a structure. These waves can be detected and analyzed to provide the location and severity of damage as part of a structural health monitoring (SHM) system. This methodology of damage detection is commonly known as acoustic emission (AE) monitoring, and is widely used on a variety of applications on civil structures. AE has been widely considered for SHM of aerospace vehicles. Numerous successful ground and flight test demonstrations have been performed, which show the viability of the technology for damage monitoring in aerospace structures. However, one significant current limitation for application of AE techniques on aerospace vehicles is the large size, mass, and power requirements for the necessary monitoring instrumentation. To address this issue, a prototype multiplexing approach has been developed and demonstrated in this study, which reduces the amount of AE monitoring instrumentation required. Typical time division multiplexing techniques that are commonly used to monitor strain, pressure and temperature sensors are not applicable to AE monitoring because of the asynchronous and widely varying rates of AE signal occurrence. Thus, an event based multiplexing technique was developed. In the initial prototype circuit, inputs from eight sensors in a linear array were multiplexed into two data acquisition channels. The multiplexer rapidly switches, in less than one microsecond, allowing the signals from two sensors to be acquired by a digitizer. The two acquired signals are from the sensors on either side of the trigger sensor. This enables the capture of the first arrival of the waves, which cannot be accomplished with the signal from the trigger sensor. The propagation delay to the slightly more distant neighboring sensors makes this possible. The arrival time from this first arrival provides a more accurate source location determination. The multiplexer also identifies which channels are acquired by encoding TTL logic pulses onto the latter portion of the signals. This prototype system was demonstrated using pencil lead break (Hsu-Neilsen) sources on an aluminum plate. It performed as designed providing rapid low noise trigger based switching with encoded channel identification. this multiplexing approach is not limited to linear arrays, but can be easily extended to monitor sensors in planar ot three dimensional arrays. A 32 channel multiplexing system is under development that will allow arbitrary sensor placement. Another benefit of this multiplexing system is the reduction in the expense of data acquisition hardware. In addition, the reduced weight and power requirements are of extreme importance for proposed AE systems on aerospace vehicles.

Smart-aggregate-based damage detection of fiber-reinforced-polymer-strengthened columns under reversed cyclic loading

NASA Astrophysics Data System (ADS)

Howser, Rachel; Moslehy, Yashar; Gu, Haichang; Dhonde, Hemant; Mo, Y. L.; Ayoub, Ashraf; Song, Gangbing

2011-07-01

Structural health monitoring is an important aspect of the maintenance of large civil infrastructures, especially for bridge columns in areas of high seismic activity. In this project, recently developed innovative piezoceramic-based sensors were utilized to perform the health monitoring of a shear-critical reinforced concrete (RC) bridge column subjected to reversed cyclic loading. After the column failed, it was wrapped with fiber reinforced polymer (FRP) sheets, commonly used to retrofit seismically damaged structures. The FRP-strengthened column was retested under the same reversed cyclic loading pattern. Innovative piezoceramic-based sensors, called 'smart aggregates', were utilized as transducers for health monitoring purposes. On the basis of the smart aggregates developed, an active-sensing approach and an impact-hammer-based approach were used to evaluate the health status of the RC column during the loading procedure. Wave transmission energy is attenuated by the existence of cracks during the loading procedure, and this attenuation phenomenon alters the curve of the transfer function between the actuator and sensor. To detect the damage occurrence and evaluate the damage severity, transfer function curves were compared with those obtained during the period of healthy status. A transfer-function-based damage index matrix was developed to demonstrate the damage severity at different locations. Experimental results verified the effectiveness of the smart aggregates in health monitoring of the FRP-strengthened column as well as the unstrengthened column. The experimental results show that the proposed smart-aggregate-based approach can successfully detect damage occurrence and evaluate its severity.

Educating next-generation civil engineers about smart structures technology

NASA Astrophysics Data System (ADS)

Zhang, Yunfeng

2005-05-01

The implementation of smart structures technology in the design, construction and maintenance of civil and mechanical systems have been shown beneficial to the performance enhancement, operating efficiency and reliability of structural systems. However, most of today's engineering students are unaware of the remarkable properties of smart sensors and many applications of smart structures technology. It is thus desirable to prepare the future engineers of the society for the cutting-edge technologies in smart structures, for which they may see broad application in their generation. Pioneering work in incorporating smart structures technologies into civil engineering curriculum has been done by the writer at Lehigh University and is described in this paper. In particular, a graduate-level course entitled "Smart Structural Systems" has been taught in the Spring Semester of Year 2004 at Lehigh University. To better convey the course material to students, a smart structures test-bed, which is used not only to showcase various technological aspects of a smart structural system but also offer students an opportunity to gain hands-on experience by doing experiments has been under development at Lehigh University. The hands-on experience that could be developed with the smart structures test-bed is believed being essential for students to have a good understanding and mastering of the smart structures technologies.

Structural modal parameter identification using local mean decomposition

NASA Astrophysics Data System (ADS)

Keyhani, Ali; Mohammadi, Saeed

2018-02-01

Modal parameter identification is the first step in structural health monitoring of existing structures. Already, many powerful methods have been proposed for this concept and each method has some benefits and shortcomings. In this study, a new method based on local mean decomposition is proposed for modal identification of civil structures from free or ambient vibration measurements. The ability of the proposed method was investigated using some numerical studies and the results compared with those obtained from the Hilbert-Huang transform (HHT). As a major advantage, the proposed method can extract natural frequencies and damping ratios of all active modes from only one measurement. The accuracy of the identified modes depends on their participation in the measured responses. Nevertheless, the identified natural frequencies have reasonable accuracy in both cases of free and ambient vibration measurements, even in the presence of noise. The instantaneous phase angle and the natural logarithm of instantaneous amplitude curves obtained from the proposed method have more linearity rather than those from the HHT algorithm. Also, the end effect is more restricted for the proposed method.

Output-Based Structural Damage Detection by Using Correlation Analysis Together with Transmissibility

PubMed Central

Cao, Hongyou; Liu, Quanmin; Wahab, Magd Abdel

2017-01-01

Output-based structural damage detection is becoming increasingly appealing due to its potential in real engineering applications without any restriction regarding excitation measurements. A new transmissibility-based damage detection approach is presented in this study by combining transmissibility with correlation analysis in order to strengthen its performance in discriminating damaged from undamaged scenarios. From this perspective, damage detection strategies are hereafter established by constructing damage-sensitive indicators from a derived transmissibility. A cantilever beam is numerically analyzed to verify the feasibility of the proposed damage detection procedure, and an ASCE (American Society of Civil Engineers) benchmark is henceforth used in the validation for its application in engineering structures. The results of both studies reveal a good performance of the proposed methodology in identifying damaged states from intact states. The comparison between the proposed indicator and the existing indicator also affirms its applicability in damage detection, which might be adopted in further structural health monitoring systems as a discrimination criterion. This study contributed an alternative criterion for transmissibility-based damage detection in addition to the conventional ones. PMID:28773218

The Idea to Promote the Development of E-Government in the Civil Aviation System

NASA Astrophysics Data System (ADS)

Renliang, Jiang

E-government has a significant impact on the organizational structure, working mechanism, operating methods and behavior patterns of the civil aviation administration department.The purpose of this research is to find some countermeasures propelling the electronization, network and office automation of the civil aviation system.The method used in the study was field and literature research.The studies showed that government departments in the civil aviation system could promote the development of e-government further by promoting open administration and implementing democratic and scientific decision-making, strengthening the popularization of information technology and information technology training on civil servants, paying attention to the integration and sharing of information resources, formulating a standard e-government system for the civil aviation system, developing the legal security system for the e-government and strengthening the network security.

Civil Engineering Applications of Ground Penetrating Radar: Research Perspectives in COST Action TU1208

NASA Astrophysics Data System (ADS)

Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Slob, Evert; Tosti, Fabio

2013-04-01

Ground Penetrating Radar (GPR) is a safe, non-destructive and non-invasive imaging technique that can be effectively used for advanced inspection of composite structures and for diagnostics affecting the whole life-cycle of civil engineering works. GPR provides high resolution images of structures and subsurface through wide-band electromagnetic waves. It can be employed for the surveying of roads, pavements, bridges, tunnels, for detecting underground cavities and voids, for utility sensing, for the inspection of buildings, reinforced concrete and pre-cast concrete structures, for geotechnical investigation, in foundation design, as well as for several other purposes. Penetration and resolution of GPR depend primarily on the transmitting frequency of the equipment, the antenna characteristics, the electrical properties of the ground or of the surveyed material, and the contrasting electrical properties of the targets with respect to the surrounding medium. Generally there is a direct relationship between the transmitter frequency and the resolution that can be obtained; conversely there is an inverse relationship between frequency and penetration depth. GPR works best in dry ground environments, but can also give good results in wet, saturated materials; it does not work well in saline conditions, in high-conductivity media and through dense clays which limit signal penetration. Different approaches can be employed in the processing of collected GPR data. Once data have been processed, they still have to be analysed. This is a challenging problem, since interpretation of GPR radargrams is typically non-intuitive and considerable expertise is needed. In the presence of a complex scenario, an accurate electromagnetic forward solver is a fundamental tool for the validation of data interpretation. It can be employed for the characterization of scenarios, as a preliminary step that precedes a survey, or to gain a posteriori a better understanding of measured data. It can be used by GPR operators to identify the signatures generated by uncommon targets or by composite structures. Repeated evaluations of the electromagnetic field scattered by known targets can be performed by a forward solver, in order to estimate - through comparison with measured data - the physics and geometry of the region investigated by the GPR. It is possible to identify three main areas, in the GPR field, that have to be addressed in order to promote the use of this technology in the civil engineering. These are: a) increase of the system sensitivity to enable the usability in a wider range of conditions; b) research novel data processing algorithms/analysis tools for the interpretation of GPR results; c) contribute to the development of new standards and guidelines and to training of end users, that will also help to increase the awareness of operators. In this framework, the COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar", proposed by Lara Pajewski, "Roma Tre" University, Rome, Italy, has been approved in November 2012 and is going to start in April 2013. It is a 4-years ambitious project already involving 17 European Countries (AT, BE, CH, CZ, DE, EL, ES, FI, FR, HR, IT, NL, NO, PL, PT, TR, UK), as well as Australia and U.S.A. The project will be developed within the frame of a unique approach based on the integrated contribution of University researchers, software developers, geophysics experts, Non-Destructive Testing equipment designers and producers, end users from private companies and public agencies. The main objective of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst promoting the effective use of this safe and non-destructive technique in the monitoring of systems. In this interdisciplinary Action, advantages and limitations of GPR will be highlighted, leading to the identification of gaps in knowledge and technology. Protocols and guidelines for European Standards will be developed, for an effective application of GPR in civil engineering. A novel GPR will be designed and realized: a multi-static system, with dedicated software and calibration procedures, able to construct real-time lane three-dimensional high resolution images of investigated areas. Advanced electromagnetic-scattering and data-processing techniques will be developed. The understanding of relationships between geophysical parameters and civil-engineering needs will be improved. Freeware software will be released, for inspection and monitoring of structures and infrastructures, buried-object localization, shape reconstruction and estimation of useful parameters. A high level training program will be organized. Mobility of early career researchers will be encouraged. The scientific work-plan of the Action is open, to ensure that experts all over the world, who did not participate in the preparation of the proposal but are interested in the project, may join the Action and participate in its activities. More information about the project can be found at http://www.cost.eu/domains_actions/tud/Actions/TU1208.

Prospects for a civil/military transport aircraft

NASA Technical Reports Server (NTRS)

Jobe, C. E.; Noggle, L. W.; Whitehead, A. H., Jr.

1978-01-01

The similarities and disparities between commercial and military payloads, design features, missions, and transport aircraft are enumerated. Two matrices of civil/military transport aircraft designs were evaluated to determine the most cost effective payloads for a projected commercial route structure and air freight market. The probability of this market developing and the prospects for alternate route structures and freight markets are evaluated along with the possible impact on the aircraft designs. Proposals to stimulate the market and increase the viability of the common aircraft concept are reviewed and the possible impact of higher cargo demand on prospects for common civil/military freighters is postulated. The implications of planned advanced technology developments on the aircraft performance and cost are also considered.

Airborne remote sensors applied to engineering geology and civil works design investigations

NASA Technical Reports Server (NTRS)

Gelnett, R. H.

1975-01-01

The usefulness of various airborne remote sensing systems in the detection and identification of regional and specific geologic structural features that may affect the design and location of engineering structures on major civil works projects is evaluated. The Butler Valley Dam and Blue Lake Project in northern California was selected as a demonstration site. Findings derived from the interpretation of various kinds of imagery used are given.

Tapered Polymer Fiber Sensors for Reinforced Concrete Beam Vibration Detection.

PubMed

Luo, Dong; Ibrahim, Zainah; Ma, Jianxun; Ismail, Zubaidah; Iseley, David Thomas

2016-12-16

In this study, tapered polymer fiber sensors (TPFSs) have been employed to detect the vibration of a reinforced concrete beam (RC beam). The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well with Kistler accelerometers. The experimental results found that both the accelerometer and TPFS detected the natural frequency function of a vibrated RC beam well. The mode shapes of the RC beam were also found by using the TPFSs. The proposed vibration detection method provides a cost-comparable solution for a structural health monitoring (SHM) system in civil engineering.

Tapered Polymer Fiber Sensors for Reinforced Concrete Beam Vibration Detection

PubMed Central

Luo, Dong; Ibrahim, Zainah; Ma, Jianxun; Ismail, Zubaidah; Iseley, David Thomas

2016-01-01

In this study, tapered polymer fiber sensors (TPFSs) have been employed to detect the vibration of a reinforced concrete beam (RC beam). The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well with Kistler accelerometers. The experimental results found that both the accelerometer and TPFS detected the natural frequency function of a vibrated RC beam well. The mode shapes of the RC beam were also found by using the TPFSs. The proposed vibration detection method provides a cost-comparable solution for a structural health monitoring (SHM) system in civil engineering. PMID:27999245

Thermal effects on an embedded grating sensor in an FRP structure

NASA Astrophysics Data System (ADS)

Lau, Kin-tak; Yuan, Libo; Zhou, Li-min

2001-08-01

Much research has been carried out in the field of using optical fibre sensors as internal strain and temperature measuring devices for advanced composite structures in recent years. The specific application is the use of embedded optical fibre sensors for smart composite reinforcement for strain monitoring in an innovative civil engineering structure, particularly for the structure after rehabilitation. Researchers have also paid attention to using the optical fibre sensor for monitoring the condition of composite materials during manufacturing and curing processes. However, heat induced in the curing process may influence the accuracy of measurement and eventuate in causing damage at the bond interface between the optical fibre and the surrounding matrix material because of the different thermal properties of silica fibre and composite materials. In this paper, a simple theoretical model is introduced to determine the interfacial properties of the embedded optical fibre system in composite laminates with different values of the coefficient of thermal expansion under different temperature environments. A finite-element method is used to compare the result from the theoretical prediction. The results show that the maximum shear stress in the coating layer decreases with increasing surrounding temperature when the optical fibre is embedded into carbon and Kevlar fibre composites. In contrast, increasing the temperature when the optical fibre is embedded into glass fibre composite results in the increase of maximum shear stress of the material. The compaction pressure distribution along the circumference of the coating layer also varies with temperature.

Continuous monitoring of large civil structures using a digital fiber optic motion sensor system

NASA Astrophysics Data System (ADS)

Hodge, Malcolm H.; Kausel, Theodore C., Jr.

1998-03-01

There is no single attribute which can always predict structural deterioration. Accordingly, we have developed a scheme for monitoring a wide range of incipient deterioration parameters, all based on a single motion sensor concept. In this presentation, we describe how an intrinsically low power- consumption fiber optic harness can be permanently deployed to poll an array of optical sensors. The function and design of these simple, durable, and naturally digital sensors is described, along with the manner in which they have been configured to collect information for changes in the most important structural aspects. The SIMS system is designed to interrogate each sensor up to five-thousand times per second for the life of the structure, and to report sensor data back to a remote computer base for current and long-term analysis, and is directed primarily towards bridges. By suitably modifying the actuation of this very precise motion sensor, SIMS is able to track bridge deck deflection and vibration, expansion joint travel, concrete and rebar corrosion, pothole development, pier scour and tilt. Other sensors will track bolt clamp load, cable tension, and metal fatigue. All of these data are received within microseconds, which means that appropriate computer algorithm manipulations can be carried out to correlate one sensor with other sensors in real time. This internal verification feature automatically enhances confidence in the system's predictive ability and alerts the user to any anomalous behavior.

Combination of digital signal processing methods towards an improved analysis algorithm for structural health monitoring.

NASA Astrophysics Data System (ADS)

Pentaris, Fragkiskos P.; Makris, John P.

2013-04-01

In Structural Health Monitoring (SHM) is of great importance to reveal valuable information from the recorded SHM data that could be used to predict or indicate structural fault or damage in a building. In this work a combination of digital signal processing methods, namely FFT along with Wavelet Transform is applied, together with a proposed algorithm to study frequency dispersion, in order to depict non-linear characteristics of SHM data collected in two university buildings under natural or anthropogenic excitation. The selected buildings are of great importance from civil protection point of view, as there are the premises of a public higher education institute, undergoing high use, stress, visit from academic staff and students. The SHM data are collected from two neighboring buildings that have different age (4 and 18 years old respectively). Proposed digital signal processing methods are applied to the data, presenting a comparison of the structural behavior of both buildings in response to seismic activity, weather conditions and man-made activity. Acknowledgments This work was supported in part by the Archimedes III Program of the Ministry of Education of Greece, through the Operational Program "Educational and Lifelong Learning", in the framework of the project entitled «Interdisciplinary Multi-Scale Research of Earthquake Physics and Seismotectonics at the front of the Hellenic Arc (IMPACT-ARC) » and is co-financed by the European Union (European Social Fund) and Greek National Fund.

Detection of Steel Fatigue Cracks with Strain Sensing Sheets Based on Large Area Electronics

PubMed Central

Yao, Yao; Glisic, Branko

2015-01-01

Reliable early-stage damage detection requires continuous monitoring over large areas of structure, and with sensors of high spatial resolution. Technologies based on Large Area Electronics (LAE) can enable direct sensing and can be scaled to the level required for Structural Health Monitoring (SHM) of civil structures and infrastructure. Sensing sheets based on LAE contain dense arrangements of thin-film strain sensors, associated electronics and various control circuits deposited and integrated on a flexible polyimide substrate that can cover large areas of structures. This paper presents the development stage of a prototype strain sensing sheet based on LAE for crack detection and localization. Two types of sensing-sheet arrangements with size 6 × 6 inch (152 × 152 mm) were designed and manufactured, one with a very dense arrangement of sensors and the other with a less dense arrangement of sensors. The sensing sheets were bonded to steel plates, which had a notch on the boundary, so the fatigue cracks could be generated under cyclic loading. The sensors within the sensing sheet that were close to the notch tip successfully detected the initialization of fatigue crack and localized the damage on the plate. The sensors that were away from the crack successfully detected the propagation of fatigue cracks based on the time history of the measured strain. The results of the tests have validated the general principles of the proposed sensing sheets for crack detection and identified advantages and challenges of the two tested designs. PMID:25853407

Robust evaluation of time series classification algorithms for structural health monitoring

NASA Astrophysics Data System (ADS)

Harvey, Dustin Y.; Worden, Keith; Todd, Michael D.

2014-03-01

Structural health monitoring (SHM) systems provide real-time damage and performance information for civil, aerospace, and mechanical infrastructure through analysis of structural response measurements. The supervised learning methodology for data-driven SHM involves computation of low-dimensional, damage-sensitive features from raw measurement data that are then used in conjunction with machine learning algorithms to detect, classify, and quantify damage states. However, these systems often suffer from performance degradation in real-world applications due to varying operational and environmental conditions. Probabilistic approaches to robust SHM system design suffer from incomplete knowledge of all conditions a system will experience over its lifetime. Info-gap decision theory enables nonprobabilistic evaluation of the robustness of competing models and systems in a variety of decision making applications. Previous work employed info-gap models to handle feature uncertainty when selecting various components of a supervised learning system, namely features from a pre-selected family and classifiers. In this work, the info-gap framework is extended to robust feature design and classifier selection for general time series classification through an efficient, interval arithmetic implementation of an info-gap data model. Experimental results are presented for a damage type classification problem on a ball bearing in a rotating machine. The info-gap framework in conjunction with an evolutionary feature design system allows for fully automated design of a time series classifier to meet performance requirements under maximum allowable uncertainty.

A guided-wave system for monitoring the wing skin-to-spar bond in unmanned aerial vehicles

NASA Astrophysics Data System (ADS)

Matt, Howard; Bartoli, Ivan; Lanza di Scalea, Francesco; Marzani, Alessandro; Coccia, Stefano; Oliver, Joseph; Kosmatka, John; Rizzo, Piervincenzo; Restivo, Gaetano

2005-05-01

Unmanned Aerial Vehicles (UAVs) are being increasingly used in military as well as civil applications. A critical part of the structure is the adhesive bond between the wing skin and the supporting spar. If not detected early, bond defects originating during manufacturing or in service flight can lead to inefficient flight performance and eventual global failure. This paper will present results from a bond inspection system based on attached piezoelectric disks probing the skin-to-spar bondline with ultrasonic guided waves in the hundreds of kilohertz range. The test components were CFRP composite panels of two different fiber layups bonded to a CFRP composite tube using epoxy adhesive. Three types of bond conditions were simulated, namely regions of poor cohesive strength, regions with localized disbonds and well bonded regions. The root mean square and variance of the received time-domain signals and their discrete wavelet decompositions were computed for the dominant modes propagating through the various bond regions in two different inspection configurations. Semi-analytical finite element analysis of the bonded multilayer joint was also carried out to identify and predict the sensitivity of the predominant carrier modes to the different bond defects. Emphasis of this research is based upon designing a built-in system for monitoring the structural integrity of bonded joints in UAVs and other aerospace structures.

The design of automatic software testing module for civil aviation information system

NASA Astrophysics Data System (ADS)

Qi, Qi; Sun, Yang

2018-05-01

In this paper, the practical innovation design is carried out according to the urgent needs of the automatic testing module of civil aviation information system. Firstly, the background and significance of the automatic testing module of civil aviation information system is expounded, and the current research status of automatic testing module and the advantages and disadvantages of related software are analyzed. Then, from the three aspects of macro demand, module functional requirement and module nonfunctional demand, we further study the needs of automatic testing module of civil aviation information system. Finally, from the four aspects of module structure, module core function, database and security, we have made an innovative plan for the automatic testing module of civil aviation information system.

Smart fiber-reinforced polymer anchorage system with optical fiber Bragg grating sensors

NASA Astrophysics Data System (ADS)

Huang, Minghua; Zhou, Zhi; He, Jianping; Chen, Genda; Ou, Jinping

2010-03-01

Civil Engineers have used fiber reinforced polymer (FRP) with high axial strength as an effective and economical alternative to steel in harsh corrosion environments. However, the practical applications of FRP are limited by the tendency of FRP materials to fail suddenly under lateral pressure and surface injury. For example, shear stresses result from the bonding effect between the FRP material and the structure of the anchorage system due to the lower shear strength of FRP. This paper proposes a novel smart FRP anchorage system with embedded optical fiber Bragg grating (FBG) sensors to monitor the axial strain state and accordingly the interfacial shear stress, as well as the interfacial damage characteristics of FRP anchorage. One FBG sensor was embedded in an FRP rod outside the anchorage region to evaluate the properties of the material, and seven FBG sensors were distributed along the rod in the anchor to monitor the axial strain variations and study the interfacial mechanical behaviors of the smart FRP anchorage under a static pulling load. The experimental results agreed well with theoretical predictions. The smart FRP anchorage system with optical FBG sensors proves effective and practical for monitoring the long-term mechanical behavior of FRP anchorage systems.

40 CFR 63.762 - Affirmative defense for violations of emission standards during malfunction.

Code of Federal Regulations, 2013 CFR

2013-07-01

... an affirmative defense to a claim for civil penalties for violations of such standards that are... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering...

40 CFR 63.1272 - Affirmative defense for violations of emission standards during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... an affirmative defense to a claim for civil penalties for violations of such standards that are... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering...

40 CFR 63.762 - Affirmative defense for violations of emission standards during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... an affirmative defense to a claim for civil penalties for violations of such standards that are... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering...

40 CFR 63.1272 - Affirmative defense for violations of emission standards during malfunction.

Code of Federal Regulations, 2013 CFR

2013-07-01

... an affirmative defense to a claim for civil penalties for violations of such standards that are... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering...

5 CFR 575.112 - Internal monitoring requirements and revocation or suspension of authority.

Code of Federal Regulations, 2010 CFR

2010-01-01

... agency's headquarters level before paying a recruitment incentive to such employees; or (2) Revoke or... paying a recruitment incentive to such employees. ... MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, RELOCATION, AND RETENTION INCENTIVES; SUPERVISORY...

The factor structure of the 12-item general health questionnaire (GHQ-12) in young Chinese civil servants.

PubMed

Liang, Ying; Wang, Lei; Yin, Xican

2016-09-26

The 12-item General Health Questionnaire (GHQ-12) is a commonly used screening instrument for measuring mental disorders. However, few studies have measured the mental health of Chinese professionals or explored the factor structure of the GHQ-12 through investigations of young Chinese civil servants. This study analyses the factor structure of the GHQ-12 on young Chinese civil servants. Respondents include 1051 participants from six cities in eastern China. Exploratory Factor Analysis (EFA) is used to identify the potential factor structure of the GHQ-12. Confirmatory Factor Analysis (CFA) models of previous studies are referred to for model fitting. The results indicate the GHQ-12 has very good reliability and validity. All ten CFA models are well fitted with the actual data. All the ten models are feasible and fit the data equally well. The Chinese version of the GHQ-12 is suitable for professional groups and can serve as a screening tool to detect anxiety and psychiatric disorders.

Preliminary structural sizing of a Mach 3.0 high-speed civil transport model

NASA Technical Reports Server (NTRS)

Blackburn, Charles L.

1992-01-01

An analysis has been performed pertaining to the structural resizing of a candidate Mach 3.0 High Speed Civil Transport (HSCT) conceptual design using a computer program called EZDESIT. EZDESIT is a computer program which integrates the PATRAN finite element modeling program to the COMET finite element analysis program for the purpose of calculating element sizes or cross sectional dimensions. The purpose of the present report is to document the procedure used in accomplishing the preliminary structural sizing and to present the corresponding results.

Job Prospects for Civil Engineers.

ERIC Educational Resources Information Center

Basta, Nicholas

1985-01-01

Government programs and renewed industrial activity have combined with stable enrollments to create bright job prospects for civil engineers. Areas with good opportunities include highway reconstruction and rehabilitation, water-resource management, and new factory construction. The subspecialty of structural engineering has a growing need in…

APPS-IV Civil Works Data Extraction/Data Base Application Study

DTIC Science & Technology

1982-09-01

QA 1 2 3 889 ETL-031 0 APPS-IV civil works data extraction/data base application study (phase 1) Jonathan C. Howland Autometric, Incorporated 5205... STUDY FINAL REPORT (PHASE I) 6. PERFORMING ORG. REPORT NUMBER 900-0081 7. AUTHOR(@) S. CONTRACT ON GRANT NUMBER(B) DAAK70-8 I -C-026 1 Jonathan C...CAPIR system was applied to a flood damage potential study . The particular applications were structure mapping and land use interpretation. A Civil

Photocopy of plan (in collection of U.S. Coast Guard Civil ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of plan (in collection of U.S. Coast Guard Civil Engineering Unit Providence, Warwick, RI), U.S. Coast Guard Civil Engineering, third district, Sandy Hook L/B Station, Fort Hancock, NJ, boathouse, plot plan, floor plan, elevation. & section., November 8, 1963 Proposed boathouse wharf B, L.A.S. building shown on wharf A - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

Photocopy of plan (in collection of U.S. Coast Guard Civil ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of plan (in collection of U.S. Coast Guard Civil Engineering Unit Providence, Warwick, RI), U.S. Coast Guard Civil Engineering, third district, Sandy Hook L/B Station, Sandy Hook N.J., buoy hoist installation and bldg alterations, January 3, 1952 Details of 4 ton hoist and building, wharf B - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

Photocopy of plan (in collection of U.S. Coast Guard Civil ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of plan (in collection of U.S. Coast Guard Civil Engineering Unit Providence, Warwick, RI) U.S. Coast Guard, shore maintenance detachment, New York, mooring facilities for 110 WPB's Station Sandy Hook, Middletown Township, New Jersey, civil demolition of wharf & pier E December 22, 1988 detail of framing and decking wharf B - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

40 CFR 60.74a - Affirmative defense for violations of emission standards during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... affirmative defense to a claim for civil penalties for violations of such standards that are caused by... analysis shall also specify, using best monitoring methods and engineering judgment, the amount of any...

40 CFR 60.74a - Affirmative defense for violations of emission standards during malfunction.

Code of Federal Regulations, 2013 CFR

2013-07-01

... affirmative defense to a claim for civil penalties for violations of such standards that are caused by... analysis shall also specify, using best monitoring methods and engineering judgment, the amount of any...

40 CFR 60.286a - Affirmative defense for violations of emission standards during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., you may assert an affirmative defense to a claim for civil penalties for violations of such standards... malfunction event at issue. The analysis must also specify, using best monitoring methods and engineering...

40 CFR 63.1344 - Affirmative defense for violation of emission standards during malfunction.

Code of Federal Regulations, 2013 CFR

2013-07-01

... defense to a claim for civil penalties for violations of such standards that are caused by malfunction, as... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering...

40 CFR 63.1344 - Affirmative defense for violation of emission standards during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... defense to a claim for civil penalties for violations of such standards that are caused by malfunction, as... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering...

Changing Families Changing Schools.

ERIC Educational Resources Information Center

Evans, Robert

The decline in civility, social responsibility, and institutional affiliation challenges the nature of schooling. Child development in the 1990s family is under pressure from changes that deny children the three basic essentials (nurture, structure, and latitude) for psychological health, effective learning, and civility, and that require children…

Climate not to blame for African civil wars

PubMed Central

Buhaug, Halvard

2010-01-01

Vocal actors within policy and practice contend that environmental variability and shocks, such as drought and prolonged heat waves, drive civil wars in Africa. Recently, a widely publicized scientific article appears to substantiate this claim. This paper investigates the empirical foundation for the claimed relationship in detail. Using a host of different model specifications and alternative measures of drought, heat, and civil war, the paper concludes that climate variability is a poor predictor of armed conflict. Instead, African civil wars can be explained by generic structural and contextual conditions: prevalent ethno-political exclusion, poor national economy, and the collapse of the Cold War system. PMID:20823241

Semi Active Control of Civil Structures, Analytical and Numerical Studies

NASA Astrophysics Data System (ADS)

Kerboua, M.; Benguediab, M.; Megnounif, A.; Benrahou, K. H.; Kaoulala, F.

Structural control for civil structures was born out of a need to provide safer and more efficient designs with the reality of limited resources. The purpose of structural control is to absorb and to reflect the energy introduced by dynamic loads such as winds, waves, earthquakes, and traffic. Today, the protection of civil structures from severe dynamic loading is typically achieved by allowing the structures to be damaged. Semi-active control devices, also called "smart" control devices, assume the positive aspects of both the passive and active control devices. A semi-active control strategy is similar to the active control strategy. Only here, the control actuator does not directly apply force to the structure, but instead it is used to control the properties of a passive energy device, a controllable passive damper. Semi-active control strategies can be used in many of the same civil applications as passive and active control. One method of operating smart cable dampers is in a purely passive capacity, supplying the dampers with constant optimal voltage. The advantages to this strategy are the relative simplicity of implementing the control strategy as compared to a smart or active control strategy and that the dampers are more easily optimally tuned in- place, eliminating the need to have passive dampers with unique optimal damping coefficients. This research investigated semi-active control of civil structures for natural hazard mitigation. The research has two components, the seismic protection of buildings and the mitigation of wind-induced vibration in structures. An ideal semi-active motion equation of a composite beam that consists of a cantilever beam bonded with a PZT patch using Hamilton's principle and Galerkin's method was treated. A series R-L and a parallel R-L shunt circuits are coupled into the motion equation respectively by means of the constitutive relation of piezoelectric material and Kirchhoff's law to control the beam vibration. A numerical example of the parallel R-L piezoelectric vibration shunt control simulated with MATLAB® is presented. An analytical study of the resistor-inductor (R-L) passive piezoelectric vibration shunt control of a cantilever beam was undertaken. The modal and strain analyses were performed by varying the material properties and geometric configurations of the piezoelectric transducer in relation to the structure in order to maximize the mechanical strain produced in the piezoelectric transducer.

Local-based damage detection of cyclically loaded bridge piers using wireless sensing units

NASA Astrophysics Data System (ADS)

Hou, Tsung-Chin; Lynch, Jerome P.; Parra-Montesinos, Gustavo

2005-05-01

Concrete bridge piers are a common structural element employed in the design of bridges and elevated roadways. In order to ensure adequate behavior under earthquake-induced displacements, extensive reinforcement detailing in the form of closely spaced ties or spirals is necessary, leading to congestion problems and difficulties during concrete casting. Further, costly repairs are often necessary in bridge piers after a major earthquake which in some cases involve the total or partial shutdown of the bridge. In order to increase the damage tolerance while relaxing the transverse reinforcement requirements of bridge piers, the use of high-performance fiber reinforced cementitious composites (HPFRCC) in earthquake-resistant bridge piers is explored. HPFRCCs are a relatively new class of cementitious material for civil structures with tensile strain-hardening behavior and high damage tolerance. To monitor the behavior of this new class of material in the field, low-cost wireless monitoring technologies will be adopted to provide HPFRCC structural elements the capability to accurately monitor their performance and health. In particular, the computational core of a wireless sensing unit can be harnessed to screen HPFRCC components for damage in real-time. A seismic damage index initially proposed for flexure dominated reinforced concrete elements is modified to serve as an algorithmic tool for the rapid assessment of damage (due to flexure and shear) in HPFRCC bridge piers subjected to large shear reversals. Traditional and non-traditional sensor strategies of an HPFRCC bridge pier are proposed to optimize the correlation between the proposed damage index model and the damage observed in a circular pier test specimen. Damage index models are shown to be a sufficiently accurate rough measure of the degree of local-area damage that can then be wirelessly communicated to bridge officials.

Real-time vibration-based structural damage detection using one-dimensional convolutional neural networks

NASA Astrophysics Data System (ADS)

Abdeljaber, Osama; Avci, Onur; Kiranyaz, Serkan; Gabbouj, Moncef; Inman, Daniel J.

2017-02-01

Structural health monitoring (SHM) and vibration-based structural damage detection have been a continuous interest for civil, mechanical and aerospace engineers over the decades. Early and meticulous damage detection has always been one of the principal objectives of SHM applications. The performance of a classical damage detection system predominantly depends on the choice of the features and the classifier. While the fixed and hand-crafted features may either be a sub-optimal choice for a particular structure or fail to achieve the same level of performance on another structure, they usually require a large computation power which may hinder their usage for real-time structural damage detection. This paper presents a novel, fast and accurate structural damage detection system using 1D Convolutional Neural Networks (CNNs) that has an inherent adaptive design to fuse both feature extraction and classification blocks into a single and compact learning body. The proposed method performs vibration-based damage detection and localization of the damage in real-time. The advantage of this approach is its ability to extract optimal damage-sensitive features automatically from the raw acceleration signals. Large-scale experiments conducted on a grandstand simulator revealed an outstanding performance and verified the computational efficiency of the proposed real-time damage detection method.

Age 60 study, part III : consolidated database experiments final report.

DOT National Transportation Integrated Search

1994-10-01

This document is one of four products completed as a part of the Age 60 Rule research contract monitored by Pam Della Rocco, Civil Aerospace Medical Institute, Contracting Officer's Technical Representative. This work was performed. This report was a...

40 CFR 63.11226 - Affirmative defense for violation of emission standards during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... enforce the standards set forth in § 63.11201 you may assert an affirmative defense to a claim for civil... shall also specify, using best monitoring methods and engineering judgment, the amount of any emissions...

40 CFR 63.11895 - How do I assert an affirmative defense for exceedance of emission standard during malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... affirmative defense to a claim for civil penalties for violations of such standards that are caused by... shall also specify, using best monitoring methods and engineering judgment, the amount of excess...

40 CFR 63.11895 - How do I assert an affirmative defense for exceedance of emission standard during malfunction?

Code of Federal Regulations, 2014 CFR

2014-07-01

... affirmative defense to a claim for civil penalties for violations of such standards that are caused by... shall also specify, using best monitoring methods and engineering judgment, the amount of excess...

Status update on GPS integrity failure modes and effects analysis

DOT National Transportation Integrated Search

2004-01-01

GPS integrity anomalies have long been of great concern to the civil and military GPS communities for safety-of- life operations. The FAA, USCG, and their international counterparts have focused on how to accomplish integrity monitoring for safety-of...

Capacity and readiness of civil society organisations to implement community case management of malaria in Kenya

PubMed Central

Marita, Enock; Oule, Jared; Mungai, Margaret; Thiam, Sylla; Ilako, Festus

2016-01-01

Introduction Civil Society Organizations (CSOs) contribute to achieving development goals through advocacy, social mobilisation and provision of health services. CSO programming is a key component of Global Fund (GF) grants; however, CSOs face technical and governance capacity challenges in grant utilisation leading to missed opportunities for improving health at community level. Amref Health Africa was appointed Principal Recipient of a GF grant aimed at scaling up community case management of malaria through CSOs as sub-recipients in western Kenya. To identify potential risks and strengthen grant management, Amref Health Africa and the Ministry of Health conducted a capacity needs assessment to determine the capacity of CSOs to effectively utilise grants. Methods 26 selected CSOs participated in this study. Document reviews and on-site assessments and observations were conducted using structured tool. The five main assessment areas were: governance and risk management; strategic and operational planning; monitoring and evaluation; programme management; and financial management. Overall performance was grouped into four categories: 3.0-2.5 (excellent), 2.0-2.4 (good), 1.5-1.9 (fair), and 1.0-1.4 (poor). Data were collected and analysed using Excel software. Results Twenty five out of 26 CSOs were legally compliant. 14(54%) CSOs were categorized as good; 7(27%) as excellent; 3(12%) as poor and 2(8%) as fair. Most CSOs had good programme management capacity but monitoring and evaluation presented the most capacity gaps. Conclusion More than 75% of the CSOs were rated as excellent or good. A capacity building plan, programme risk management plan and oversight mechanisms were important for successful grant implementation. PMID:28523081

Combined electromechanical impedance and fiber optic diagnosis of aerospace structures

NASA Astrophysics Data System (ADS)

Schlavin, Jon; Zagrai, Andrei; Clemens, Rebecca; Black, Richard J.; Costa, Joey; Moslehi, Behzad; Patel, Ronak; Sotoudeh, Vahid; Faridian, Fereydoun

2014-03-01

Electromechanical impedance is a popular diagnostic method for assessing structural conditions at high frequencies. It has been utilized, and shown utility, in aeronautic, space, naval, civil, mechanical, and other types of structures. By contrast, fiber optic sensing initially found its niche in static strain measurement and low frequency structural dynamic testing. Any low frequency limitations of the fiber optic sensing, however, are mainly governed by its hardware elements. As hardware improves, so does the bandwidth (frequency range * number of sensors) provided by the appropriate enabling fiber optic sensor interrogation system. In this contribution we demonstrate simultaneous high frequency measurements using fiber optic and electromechanical impedance structural health monitoring technologies. A laboratory specimen imitating an aircraft wing structure, incorporating surfaces with adjustable boundary conditions, was instrumented with piezoelectric and fiber optic sensors. Experiments were conducted at different structural boundary conditions associated with deterioration of structural health. High frequency dynamic responses were collected at multiple locations on a laboratory wing specimen and conclusions were drawn about correspondence between structural damage and dynamic signatures as well as correlation between electromechanical impedance and fiber optic sensors spectra. Theoretical investigation of the effect of boundary conditions on electromechanical impedance spectra is presented and connection to low frequency structural dynamics is suggested. It is envisioned that acquisition of high frequency structural dynamic responses with multiple fiber optic sensors may open new diagnostic capabilities for fiber optic sensing technologies.

Bulletin of Forest Fire risk in Albania- The experience of the Albania National Centre for forecast and Monitoring of Natural Risks

NASA Astrophysics Data System (ADS)

Berdufi, I.; Jaupaj, O.; Marku, M.; Deda, M.; Fiori, E.; D'Andrea, M.; Biondi, G.; Fioruci, P.; Massabò, M.; Zorba, P.; Gjonaj, M.

2012-04-01

In the territory of Albania usually every year around 1000 ha are affected by forest fires, from which about 500 ha are completely destroyed. The number of forest fires (nf), with the burning surface (bs) in years has been like this: during the years 1988-1998: nf / bs = 2.19, 1998-2001: nf / bs = 5.66, year 2002 -2005: nf / bs = 8.2, and during the years 2005-2006: nf / bs = 11.9, while economic losses in a year by forest fires is about 2 million of Euro. The increase in years of these figures and the last floods which happened in the last two years in Shkoder, led to an international cooperation, that between the Italian Civil Protection Department and the Albania General Directorate of Civil Emergency. The focus of this cooperation was the building capacity of the Albanian National System of Civil Protection in forecasting, monitoring and prevention forest fires and floods risks. As a result of this collaboration the "National Center for the Forecast and Monitoring of Natural Risks", was set up at the Institute of Geosciences, Energy, Water and Environment. The Center is the first of its kind in Albania. The mission of the Center is the prediction and monitoring of the forest fire and flood risk in the Albanian territory, as a tools for risk reduction and mitigation. The first step to achieve this strategy was the implementation of the forest fires risk forecast model "RISICO". RISICO was adapted for whole Albania territory by CIMA Research Foundation. The Center, in the summer season, issues a daily bulletin. The bulletin reports the potential risk scenarios related with the ignition and propagation of fires in Albania. The bulletin is broadcasted through email or fax within 12.00 AM of each working day. It highlights where and when severe risk conditions may occur within the next 48 hours

The Civilization Course, Then and Now.

ERIC Educational Resources Information Center

Hope, Quentin M.

1986-01-01

Courses on French civilization and culture should begin with a presentation of essential information, including historical background, role of the state, and the weight and presence of the past. They should move on through public life--politics, commerce, industry, social structures, the media--to the experiences of day-to-day life. (Author/JR)

78 FR 76117 - Meeting of the National Commission on the Structure of the Air Force

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-16

... missions such as Homeland Defense, Homeland Security, and Defense Support to Civil Agencies. This will... Support, Training and Education, and other specific mission sets such as security forces, civil engineering and science and technology. --Projections and assumptions about future resource levels that will...

78 FR 76119 - Meeting of the National Commission on the Structure of the Air Force

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-16

... missions such as Homeland Defense, Homeland Security, and Defense Support to Civil Agencies. This will... Support, Training and Education, and other specific mission sets such as security forces, civil engineering and science and technology. --Projections and assumptions about future resource levels that will...

Learning by Seeing: The TEMAS Multimedia Learning Objects for Civil Engineers

ERIC Educational Resources Information Center

Cadoni, Ezio; Botturi, Luca; Forni, Daniele

2008-01-01

A goal of engineering and architecture bachelor and master's programs is to provide students with practical and technical preparation in the mechanical characterization of materials and structures: future architects and civil engineers should be able to recognize and describe different construction materials and their behavior when used for…

Approach to the assessment of the hazard. [fire released carbon fiber electrical effects

NASA Technical Reports Server (NTRS)

Huston, R. J.

1980-01-01

An overview of the carbon fiber hazard assessment is presented. The potential risk to the civil sector associated with the accidental release of carbon fibers from aircraft having composite structures was assessed along with the need for protection of civil aircraft from carbon fibers.

Laser doppler and radar interferometer for contactless measurements on unaccessible tie-rods on monumental buildings: Santa Maria della Consolazione Temple in Todi

NASA Astrophysics Data System (ADS)

Gioffré, M.; Cavalagli, N.; Pepi, C.; Trequattrini, M.

2017-01-01

Non-contact measurements can be effectively used in civil engineering to assess the variation of structural performance with time. In the last decades this approach has received considerable interests from researchers working in the field of structural health monitoring (SHM). Indeed, non-contact measurements are very attractive because it is possible to perform non intrusive and non destructive investigations even being at a significant distance from the targets. Within this context, contactless measurements of the tie-rod vibrations in the Santa Maria della Consolazione Temple in Todi (Italy) are presented in this paper. In particular, laser vibrometer and radar interferometer measurements are used to estimate natural frequencies and mode shapes. This information is crucial to obtain the tensile axial force in the tie-rods, which can be used as an indicator of structural integrity or possible failure. Furthermore, a novel approach is proposed where drones (Unmanned Aerial Vehicles) can be successfully used to improve the effectiveness and the accuracy of the experimental activities.

Investigation of Time Series Representations and Similarity Measures for Structural Damage Pattern Recognition

PubMed Central

Swartz, R. Andrew

2013-01-01

This paper investigates the time series representation methods and similarity measures for sensor data feature extraction and structural damage pattern recognition. Both model-based time series representation and dimensionality reduction methods are studied to compare the effectiveness of feature extraction for damage pattern recognition. The evaluation of feature extraction methods is performed by examining the separation of feature vectors among different damage patterns and the pattern recognition success rate. In addition, the impact of similarity measures on the pattern recognition success rate and the metrics for damage localization are also investigated. The test data used in this study are from the System Identification to Monitor Civil Engineering Structures (SIMCES) Z24 Bridge damage detection tests, a rigorous instrumentation campaign that recorded the dynamic performance of a concrete box-girder bridge under progressively increasing damage scenarios. A number of progressive damage test case datasets and damage test data with different damage modalities are used. The simulation results show that both time series representation methods and similarity measures have significant impact on the pattern recognition success rate. PMID:24191136

Biocalcification using B. pasteurii for strengthening brick masonry civil engineering structures.

PubMed

Raut, Supriya H; Sarode, D D; Lele, S S

2014-01-01

Microbiologically induced calcite precipitation in bricks by bacterium Bacillus pasteurii (NCIM 2477) using a media especially optimized for urease production (OptU) was demonstrated in this study. Effect of biocalcification activity on compressive strength and water absorption capacity of bricks was investigated. Various other parameters such as pH, growth profile, urease activity, urea breakdown and calcite precipitated were monitored during the 28 days curing period. Efficiency of B. pasteurii to form microbial aided calcite precipitate in OptU media resulted into 83.9% increase in strength of the bricks as compared to only 24.9% with standard media, nutrient broth (NB). In addition to significant increase in the compressive strength, bricks treated with B. pasteurii grown in OptU media resulted in 48.9 % reduction in water absorption capacity as compared to control bricks immersed in tap water. Thus it was successfully demonstrated that microbial calcification in optimized media by Bacillus pasteurii has good potential for commercial application to improve the life span of structures constructed with bricks, particularly structures of heritage importance.

Optoelectronic instrumentation enhancement using data mining feedback for a 3D measurement system

NASA Astrophysics Data System (ADS)

Flores-Fuentes, Wendy; Sergiyenko, Oleg; Gonzalez-Navarro, Félix F.; Rivas-López, Moisés; Hernandez-Balbuena, Daniel; Rodríguez-Quiñonez, Julio C.; Tyrsa, Vera; Lindner, Lars

2016-12-01

3D measurement by a cyber-physical system based on optoelectronic scanning instrumentation has been enhanced by outliers and regression data mining feedback. The prototype has applications in (1) industrial manufacturing systems that include: robotic machinery, embedded vision, and motion control, (2) health care systems for measurement scanning, and (3) infrastructure by providing structural health monitoring. This paper presents new research performed in data processing of a 3D measurement vision sensing database. Outliers from multivariate data have been detected and removal to improve artificial intelligence regression algorithm results. Physical measurement error regression data has been used for 3D measurements error correction. Concluding, that the joint of physical phenomena, measurement and computation is an effectiveness action for feedback loops in the control of industrial, medical and civil tasks.

Nurse Leaders' Response to Civil Unrest in the Urban Core.

PubMed

Lavin, Roberta; Goodwin Veenema, Tener; Calvert, Wilma J; Grigsby, Sheila R; Cobbina, Jennifer

Inequalities in society, culture, and finance have resulted in civil unrest, rioting, and intentional violence throughout our history. Nowhere is this currently more apparent than in the cities of Ferguson and Baltimore. It is not the civil unrest itself, but the resulting rioting and intentional violence that can create a disaster situation. This increases the care burden of health care providers during times when the governmental structure may be overwhelmed or functioning in a less than optimal manner. Beginning with the death of Michael Brown, civil unrest over the last 2 years has necessitated a closer examination of the role nurse leaders play in preparing their staff and facilities for potential results of this civil unrest. The similarities between the results of rioting and violence and natural disaster are obvious, but the differences are significant. Without adequate preparation, providers may not offer the appropriate response. Attention to the 10 "musts" for preparedness for civil unrest will facilitate a planning process and provide for a better response and recovery when communities face these issues.

Smart FBG-based FRP anchor

NASA Astrophysics Data System (ADS)

Zhou, Zhi; Zhang, Zhichun; Wang, Chuan; Ou, Jinping

2006-03-01

FRP ( Fiber Reinforced Polymer ) has become the popular material to alternate steel in civil engineering under harsh corrosion environment. But due to its low shear strength ability, the anchor for FRP is most important for its practical application. However, the strain state of the surface between FRP and anchor is not fully understood due to that there is no proper sensor to monitor the inner strain in the anchor by traditional method. In this paper, a new smart FBG-based FRP anchor is brought forward, and the inner strain distribution of FRP anchor has been monitored using FRP-OFBG sensors, a smart FBG-embedded FRP rebar, which is pre-embedded in the FRP rod and cast in the anchor. Based on the strain distribution information the bonding shear stress on the surface of FRP rod along the anchor can also be obtained. This method can supply important information for FRP anchor design and can also monitor the anchorage system, which is useful for the application of FRP in civil engineering. The experimental results also show that the smart FBG-based FRP anchor can give direct information of the load and damage of the FRP anchor.

Parametric and Non-Parametric Vibration-Based Structural Identification Under Earthquake Excitation

NASA Astrophysics Data System (ADS)

Pentaris, Fragkiskos P.; Fouskitakis, George N.

2014-05-01

The problem of modal identification in civil structures is of crucial importance, and thus has been receiving increasing attention in recent years. Vibration-based methods are quite promising as they are capable of identifying the structure's global characteristics, they are relatively easy to implement and they tend to be time effective and less expensive than most alternatives [1]. This paper focuses on the off-line structural/modal identification of civil (concrete) structures subjected to low-level earthquake excitations, under which, they remain within their linear operating regime. Earthquakes and their details are recorded and provided by the seismological network of Crete [2], which 'monitors' the broad region of south Hellenic arc, an active seismic region which functions as a natural laboratory for earthquake engineering of this kind. A sufficient number of seismic events are analyzed in order to reveal the modal characteristics of the structures under study, that consist of the two concrete buildings of the School of Applied Sciences, Technological Education Institute of Crete, located in Chania, Crete, Hellas. Both buildings are equipped with high-sensitivity and accuracy seismographs - providing acceleration measurements - established at the basement (structure's foundation) presently considered as the ground's acceleration (excitation) and at all levels (ground floor, 1st floor, 2nd floor and terrace). Further details regarding the instrumentation setup and data acquisition may be found in [3]. The present study invokes stochastic, both non-parametric (frequency-based) and parametric methods for structural/modal identification (natural frequencies and/or damping ratios). Non-parametric methods include Welch-based spectrum and Frequency response Function (FrF) estimation, while parametric methods, include AutoRegressive (AR), AutoRegressive with eXogeneous input (ARX) and Autoregressive Moving-Average with eXogeneous input (ARMAX) models[4, 5]. Preliminary results indicate that parametric methods are capable of sufficiently providing the structural/modal characteristics such as natural frequencies and damping ratios. The study also aims - at a further level of investigation - to provide a reliable statistically-based methodology for structural health monitoring after major seismic events which potentially cause harming consequences in structures. Acknowledgments This work was supported by the State Scholarships Foundation of Hellas. References [1] J. S. Sakellariou and S. D. Fassois, "Stochastic output error vibration-based damage detection and assessment in structures under earthquake excitation," Journal of Sound and Vibration, vol. 297, pp. 1048-1067, 2006. [2] G. Hloupis, I. Papadopoulos, J. P. Makris, and F. Vallianatos, "The South Aegean seismological network - HSNC," Adv. Geosci., vol. 34, pp. 15-21, 2013. [3] F. P. Pentaris, J. Stonham, and J. P. Makris, "A review of the state-of-the-art of wireless SHM systems and an experimental set-up towards an improved design," presented at the EUROCON, 2013 IEEE, Zagreb, 2013. [4] S. D. Fassois, "Parametric Identification of Vibrating Structures," in Encyclopedia of Vibration, S. G. Braun, D. J. Ewins, and S. S. Rao, Eds., ed London: Academic Press, London, 2001. [5] S. D. Fassois and J. S. Sakellariou, "Time-series methods for fault detection and identification in vibrating structures," Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol. 365, pp. 411-448, February 15 2007.

U.S. Issues Policy on Racial Harassment.

ERIC Educational Resources Information Center

Jaschik, Scott

1994-01-01

New federal Department of Education guidelines put responsibility for monitoring campus racial climate on individual colleges. The policy statement contains some elements pleasing to minority students and others attractive to civil libertarians. However, its broad definition of harassment is criticized by some. (MSE)

Autonomous measurements of bridge pier and abutment scour using motion-sensing radio transmitters.

DOT National Transportation Integrated Search

2010-01-01

Two portable Radio Frequency IDentification (RFID) systems (made by Texas Instruments and HiTAG) were developed and tested for bridge scour monitoring by the Department of Civil and Environmental Engineering at the University of Iowa. Both systems co...

Vibration-based damage detection in a concrete beam under temperature variations using AR models and state-space approaches

NASA Astrophysics Data System (ADS)

Clément, A.; Laurens, S.

2011-07-01

The Structural Health Monitoring of civil structures subjected to ambient vibrations is very challenging. Indeed, the variations of environmental conditions and the difficulty to characterize the excitation make the damage detection a hard task. Auto-regressive (AR) models coefficients are often used as damage sensitive feature. The presented work proposes a comparison of the AR approach with a state-space feature formed by the Jacobian matrix of the dynamical process. Since the detection of damage can be formulated as a novelty detection problem, Mahalanobis distance is applied to track new points from an undamaged reference collection of feature vectors. Data from a concrete beam subjected to temperature variations and damaged by several static loading are analyzed. It is observed that the damage sensitive features are effectively sensitive to temperature variations. However, the use of the Mahalanobis distance makes possible the detection of cracking with both of them. Early damage (before cracking) is only revealed by the AR coefficients with a good sensibility.

Rehabilitating asphalt highways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butalia, T.S.

2007-07-01

Coal fly ash has been used on two Ohio full-depth reclamation projects in Delaware and Warren. The object of the project carried out with the Department of Civil and Environmental Engineering and Geodetic Science at Ohio State University is to demonstrate the effective use of Class fly ash in combination with lime or lime kiln dust in the full depth reclamation of asphalt pavements. The article describes the mixes used for the highway reconstruction of part of Section Line Road Delaware County and of a road in Warren County. During construction the pavement sections were instrumented with several structural andmore » environmental monitoring devices and data is being collected on a quarterly basis. Falling Weight Deflectometer (FWD) tests to measure load defection behaviour, resilient of pavement layers and soil and base structural layer coefficient are being carried out twice a year. It was shown that use of fly ash increased the elastic modulus of base layers. This article first appeared in the Feb/May 2007 issue of Asphalt Contractor. 4 photos.« less

Photonic crystal fiber long-period gratings for structural monitoring and chemical sensing

NASA Astrophysics Data System (ADS)

Tang, Jaw-Luen; Wang, Jian-Neng

2008-03-01

We present a simple, low-cost, temperature- and strain-insensitive long-period gratings (LPGs) written in photonic crystal fibers (PCFs) that can be used as sensitive chemical solution sensors or bend sensors for a variety of industrial applications, including civil engineering, aircraft, chemistry, food industry, and biosensing. Three different configurations of PCFs have been used for this study, including a polarization maintaining PCF, a large mode area PCF and an endlessly single mode PCF. These LPGs have been characterized for their sensitivity to temperature, strain, bending, and surrounding refractive index. Transmission spectra of the LPGs were found to exhibit negligible temperature and strain sensitivities, whereas possessing usable sensitivity to refractive index and bending. This type of PCF sensor could in principle be designed for optimum sensitivity to desired measurand(s), while minimizing or removing undesirable cross-sensitivities. The unique sensing features of PCFs are particularly suited for a wide variety of applications in smart structures, embedded materials, telecommunications and sensor systems.

Demonstration of UAV deployment and control of mobile wireless sensing networks for modal analysis of structures

NASA Astrophysics Data System (ADS)

Zhou, Hao; Hirose, Mitsuhito; Greenwood, William; Xiao, Yong; Lynch, Jerome; Zekkos, Dimitrios; Kamat, Vineet

2016-04-01

Unmanned aerial vehicles (UAVs) can serve as a powerful mobile sensing platform for assessing the health of civil infrastructure systems. To date, the majority of their uses have been dedicated to vision and laser-based spatial imaging using on-board cameras and LiDAR units, respectively. Comparatively less work has focused on integration of other sensing modalities relevant to structural monitoring applications. The overarching goal of this study is to explore the ability for UAVs to deploy a network of wireless sensors on structures for controlled vibration testing. The study develops a UAV platform with an integrated robotic gripper that can be used to install wireless sensors in structures, drop a heavy weight for the introduction of impact loads, and to uninstall wireless sensors for reinstallation elsewhere. A pose estimation algorithm is embedded in the UAV to estimate the location of the UAV during sensor placement and impact load introduction. The Martlet wireless sensor network architecture is integrated with the UAV to provide the UAV a mobile sensing capability. The UAV is programmed to command field deployed Martlets, aggregate and temporarily store data from the wireless sensor network, and to communicate data to a fixed base station on site. This study demonstrates the integrated UAV system using a simply supported beam in the lab with Martlet wireless sensors placed by the UAV and impact load testing performed. The study verifies the feasibility of the integrated UAV-wireless monitoring system architecture with accurate modal characteristics of the beam estimated by modal analysis.

Fiber reinforcement of concrete structures

DOT National Transportation Integrated Search

2002-09-01

Deterioration of concrete structures due to steel corrosion is a matter of considerable concern since the repairing of these structures proved to be a costly process. Repair and rehabilitation of the civil structures needs an enduring repair material...

Uncertainty quantification in operational modal analysis with stochastic subspace identification: Validation and applications

NASA Astrophysics Data System (ADS)

Reynders, Edwin; Maes, Kristof; Lombaert, Geert; De Roeck, Guido

2016-01-01

Identified modal characteristics are often used as a basis for the calibration and validation of dynamic structural models, for structural control, for structural health monitoring, etc. It is therefore important to know their accuracy. In this article, a method for estimating the (co)variance of modal characteristics that are identified with the stochastic subspace identification method is validated for two civil engineering structures. The first structure is a damaged prestressed concrete bridge for which acceleration and dynamic strain data were measured in 36 different setups. The second structure is a mid-rise building for which acceleration data were measured in 10 different setups. There is a good quantitative agreement between the predicted levels of uncertainty and the observed variability of the eigenfrequencies and damping ratios between the different setups. The method can therefore be used with confidence for quantifying the uncertainty of the identified modal characteristics, also when some or all of them are estimated from a single batch of vibration data. Furthermore, the method is seen to yield valuable insight in the variability of the estimation accuracy from mode to mode and from setup to setup: the more informative a setup is regarding an estimated modal characteristic, the smaller is the estimated variance.

Qualitative and quantitative changes in phospholipids and proteins investigated by spectroscopic techniques in animal depression model.

PubMed

Depciuch, J; Sowa-Kucma, M; Nowak, G; Papp, M; Gruca, P; Misztak, P; Parlinska-Wojtan, M

2017-04-05

Depression becomes nowadays a high mortality civilization disease with one of the major causes being chronic stress. Raman, Fourier Transform Infra Red (FTIR) and Ultraviolet-Visible (UV-vis) spectroscopies were used to determine the changes in the quantity and structure of phospholipids and proteins in the blood serum of rats subjected to chronic mild stress, which is a common animal depression model. Moreover, the efficiency of the imipramine treatment was evaluated. It was found that chronic mild stress not only damages the structure of the phospholipids and proteins, but also decreases their level in the blood serum. A 5weeks imipramine treatment did increase slightly the quantity of proteins, leaving the damaged phospholipids unchanged. Structural information from phospholipids and proteins was obtained by UV-vis spectroscopy combined with the second derivative of the FTIR spectra. Indeed, the structure of proteins in blood serum of stressed rats was normalized after imipramine therapy, while the impaired structure of phospholipids remained unaffected. These findings strongly suggest that the depression factor, which is chronic mild stress, may induce permanent (irreversible) damages into the phospholipid structure identified as shortened carbon chains. This study shows a possible new application of spectroscopic techniques in the diagnosis and therapy monitoring of depression. Copyright © 2016 Elsevier B.V. All rights reserved.

Qualitative and quantitative changes in phospholipids and proteins investigated by spectroscopic techniques in animal depression model

NASA Astrophysics Data System (ADS)

Depciuch, J.; Sowa-Kucma, M.; Nowak, G.; Papp, M.; Gruca, P.; Misztak, P.; Parlinska-Wojtan, M.

2017-04-01

Depression becomes nowadays a high mortality civilization disease with one of the major causes being chronic stress. Raman, Fourier Transform Infra Red (FTIR) and Ultraviolet-Visible (UV-vis) spectroscopies were used to determine the changes in the quantity and structure of phospholipids and proteins in the blood serum of rats subjected to chronic mild stress, which is a common animal depression model. Moreover, the efficiency of the imipramine treatment was evaluated. It was found that chronic mild stress not only damages the structure of the phospholipids and proteins, but also decreases their level in the blood serum. A 5 weeks imipramine treatment did increase slightly the quantity of proteins, leaving the damaged phospholipids unchanged. Structural information from phospholipids and proteins was obtained by UV-vis spectroscopy combined with the second derivative of the FTIR spectra. Indeed, the structure of proteins in blood serum of stressed rats was normalized after imipramine therapy, while the impaired structure of phospholipids remained unaffected. These findings strongly suggest that the depression factor, which is chronic mild stress, may induce permanent (irreversible) damages into the phospholipid structure identified as shortened carbon chains. This study shows a possible new application of spectroscopic techniques in the diagnosis and therapy monitoring of depression.

An overview of reliability assessment and control for design of civil engineering structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, R.V. Jr.; Grigoriadis, K.M.; Bergman, L.A.

1998-06-01

Random variations, whether they occur in the input signal or the system parameters, are phenomena that occur in nearly all engineering systems of interest. As a result, nondeterministic modeling techniques must somehow account for these variations to ensure validity of the solution. As might be expected, this is a difficult proposition and the focus of many current research efforts. Controlling seismically excited structures is one pertinent application of nondeterministic analysis and is the subject of the work presented herein. This overview paper is organized into two sections. First, techniques to assess system reliability, in a context familiar to civil engineers,more » are discussed. Second, and as a consequence of the first, active control methods that ensure good performance in this random environment are presented. It is the hope of the authors that these discussions will ignite further interest in the area of reliability assessment and design of controlled civil engineering structures.« less

An embedded stress sensor for concrete SHM based on amorphous ferromagnetic microwires.

PubMed

Olivera, Jesús; González, Margarita; Fuente, José Vicente; Varga, Rastislav; Zhukov, Arkady; Anaya, José Javier

2014-10-24

A new smart concrete aggregate design as a candidate for applications in structural health monitoring (SHM) of critical elements in civil infrastructure is proposed. The cement-based stress/strain sensor was developed by utilizing the stress/strain sensing properties of a magnetic microwire embedded in cement-based composite (MMCC). This is a contact-less type sensor that measures variations of magnetic properties resulting from stress variations. Sensors made of these materials can be designed to satisfy the specific demand for an economic way to monitor concrete infrastructure health. For this purpose, we embedded a thin magnetic microwire in the core of a cement-based cylinder, which was inserted into the concrete specimen under study as an extra aggregate. The experimental results show that the embedded MMCC sensor is capable of measuring internal compressive stress around the range of 1-30 MPa. Two stress sensing properties of the embedded sensor under uniaxial compression were studied: the peak amplitude and peak position of magnetic switching field. The sensitivity values for the amplitude and position within the measured range were 5 mV/MPa and 2.5 µs/MPa, respectively.

Damage detection and quantification in a structural model under seismic excitation using time-frequency analysis

NASA Astrophysics Data System (ADS)

Chan, Chun-Kai; Loh, Chin-Hsiung; Wu, Tzu-Hsiu

2015-04-01

In civil engineering, health monitoring and damage detection are typically carry out by using a large amount of sensors. Typically, most methods require global measurements to extract the properties of the structure. However, some sensors, like LVDT, cannot be used due to in situ limitation so that the global deformation remains unknown. An experiment is used to demonstrate the proposed algorithms: a one-story 2-bay reinforce concrete frame under weak and strong seismic excitation. In this paper signal processing techniques and nonlinear identification are used and applied to the response measurements of seismic response of reinforced concrete structures subject to different level of earthquake excitations. Both modal-based and signal-based system identification and feature extraction techniques are used to study the nonlinear inelastic response of RC frame using both input and output response data or output only measurement. From the signal-based damage identification method, which include the enhancement of time-frequency analysis of acceleration responses and the estimation of permanent deformation using directly from acceleration response data. Finally, local deformation measurement from dense optical tractor is also use to quantify the damage of the RC frame structure.

I-5/Gilman advanced technology bridge project

NASA Astrophysics Data System (ADS)

Lanza di Scalea, Francesco; Karbhari, Vistasp M.; Seible, Frieder

2000-04-01

The UCSD led I-5/Gilman Advanced Technology Bridge Project will design and construct a fully functional traffic bridge of advanced composite materials across Interstate 5 in La Jolla, California. Its objective is to demonstrate the use of advanced composite technologies developed by the aerospace industry in commercial applications to increase the life expectancy of new structures and for the rehabilitation of aging infrastructure components. The structure will be a 450 ft long, 60 ft wide cable-stayed bridge supported by a 150 ft A-frame pylon with two vehicular lanes, two bicycle lanes, pedestrian walkways and utility tunnels. The longitudinal girders and pylon will be carbon fiber shells filled with concrete. The transverse deck system will consist of hollow glass/carbon hybrid tubes and a polypropylene fiber reinforced concrete deck with an arch action. Selected cables will be composite. The bridge's structural behavior will be monitored to determine how advanced composite materials perform in civil infrastructure applications. The bridge will be instrumented to obtain performance and structural health data in real time and, where possible, in a remote fashion. The sensors applied to the bridge will include electrical resistance strain gages, fiberoptic Bragg gratings and accelerometers.

Short Time Impulse Response Function (STIRF) for automatic evaluation of the variation of the dynamic parameters of reinforced concrete framed structures during strong earthquakes.

NASA Astrophysics Data System (ADS)

Carlo Ponzo, Felice; Ditommaso, Rocco

2015-04-01

This study presents an innovative strategy for automatic evaluation of the variable fundamental frequency and related damping factor of nonlinear structures during strong motion phases. Most of methods for damage detection are based on the assessment of the variations of the dynamic parameters characterizing the monitored structure. A crucial aspect of these methods is the automatic and accurate estimation of both structural eigen-frequencies and related damping factors also during the nonlinear behaviour. A new method, named STIRF (Short-Time Impulse Response Function - STIRF), based on the nonlinear interferometric analysis combined with the Fourier Transform (FT) here is proposed in order to allow scientists and engineers to characterize frequencies and damping variations of a monitored structure. The STIRF approach helps to overcome some limitation derived from the use of techniques based on simple Fourier Transform. These latter techniques provide good results when the response of the monitored system is stationary, but fails when the system exhibits a non-stationary, time-varying behaviour: even non-stationary input, soil-foundation and/or adjacent structures interaction phenomena can show the inadequacy of classic techniques to analysing the nonlinear and/or non-stationary behaviour of structures. In fact, using this kind of approach it is possible to improve some of the existing methods for the automatic damage detection providing stable results also during the strong motion phase. Results are consistent with those expected if compared with other techniques. The main advantage derived from the use of the proposed approach (STIRF) for Structural Health Monitoring is based on the simplicity of the interpretation of the nonlinear variations of the fundamental frequency and the related equivalent viscous damping factor. The proposed methodology has been tested on both numerical and experimental models also using data retrieved from shaking table tests. Based on the results provided in this study, the methodology seems to be able to evaluate fast variations (over time) of dynamic parameters of a generic reinforced concrete framed structure. Further analyses are necessary to better calibrate the length of the moving time-window (in order to minimize the spurious frequency within each Interferometric Response Function evaluated on both weak and strong motion phases) and to verify the possibility to use the STIRF to analyse the nonlinear behaviour of general systems. Acknowledgements This study was partially funded by the Italian Civil Protection Department within the project DPC-RELUIS 2014 - RS4 ''Seismic observatory of structures and health monitoring''. References R. Ditommaso, F.C. Ponzo (2015). Automatic evaluation of the fundamental frequency variations and related damping factor of reinforced concrete framed structures using the Short Time Impulse Response Function (STIRF). Engineering Structures, 82 (2015), 104-112. http://dx.doi.org/10.1016/j.engstruct.2014.10.023.

The Promise of Multiculturalism and the Permanence of Racism.

ERIC Educational Resources Information Center

Allen, Ricky Lee; Howard, Natasha

Despite many heroic victories, the Civil Rights Movement has failed to significantly transform the underlying structure of White domination [according to this didactic essay on multiculturalism and racism]. It can also be said that the multicultural movement, which was an extension of the Civil Rights Movement, has failed to transform the deep…

120. Photocopy of drawing (1958 civil engineering drawing by the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

120. Photocopy of drawing (1958 civil engineering drawing by the Ralph M. Parsons Company) STRUCTURAL DETAILS OF WAVE GUIDE ENCLOSURE AND CABLE TRAY INSTALLATION FOR LAUNCH OPERATIONS BUILDING, SHEET C42 - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Remotely Piloted Aircraft Systems (RPAS) for high resolution topography and monitoring: civil protection purposes on hydrogeological contexts

NASA Astrophysics Data System (ADS)

Bertacchini, Eleonora; Castagnetti, Cristina; Corsini, Alessandro; De Cono, Stefano

2014-10-01

The proposed work concerns the analysis of Remotely Piloted Aircraft Systems (RPAS), also known as drones, UAV (Unmanned Aerial Vehicle) or UAS (Unmanned Aerial System), on hydrogeological contexts for civil protection purposes, underlying the advantages of using a flexible and relatively low cost system. The capabilities of photogrammetric RPAS multi-sensors platform were examined in term of mapping, creation of orthophotos, 3D models generation, data integration into a 3D GIS (Geographic Information System) and validation through independent techniques such as GNSS (Global Navigation Satellite System). The RPAS used (multirotor OktoXL, of the Mikrokopter) was equipped with a GPS (Global Positioning System) receiver, digital cameras for photos and videos, an inertial navigation system, a radio device for communication and telemetry, etc. This innovative way of viewing and understanding the environment showed huge potentialities for the study of the territory, and due to its characteristics could be well integrated with aircraft surveys. However, such characteristics seem to give priority to local applications for rigorous and accurate analysis, while it remains a means of expeditious investigation for more extended areas. According to civil protection purposes, the experimentation was carried out by simulating operational protocols, for example for inspection, surveillance, monitoring, land mapping, georeferencing methods (with or without Ground Control Points - GCP) based on high resolution topography (2D and 3D information).

Using Airborne Remote Sensing to Increase Situational Awareness in Civil Protection and Humanitarian Relief - the Importance of User Involvement

NASA Astrophysics Data System (ADS)

Römer, H.; Kiefl, R.; Henkel, F.; Wenxi, C.; Nippold, R.; Kurz, F.; Kippnich, U.

2016-06-01

Enhancing situational awareness in real-time (RT) civil protection and emergency response scenarios requires the development of comprehensive monitoring concepts combining classical remote sensing disciplines with geospatial information science. In the VABENE++ project of the German Aerospace Center (DLR) monitoring tools are being developed by which innovative data acquisition approaches are combined with information extraction as well as the generation and dissemination of information products to a specific user. DLR's 3K and 4k camera system which allow for a RT acquisition and pre-processing of high resolution aerial imagery are applied in two application examples conducted with end users: a civil protection exercise with humanitarian relief organisations and a large open-air music festival in cooperation with a festival organising company. This study discusses how airborne remote sensing can significantly contribute to both, situational assessment and awareness, focussing on the downstream processes required for extracting information from imagery and for visualising and disseminating imagery in combination with other geospatial information. Valuable user feedback and impetus for further developments has been obtained from both applications, referring to innovations in thematic image analysis (supporting festival site management) and product dissemination (editable web services). Thus, this study emphasises the important role of user involvement in application-related research, i.e. by aligning it closer to user's requirements.

USDA APHIS | National Animal Health Monitoring System (NAHMS)

Science.gov Websites

USDA - APHIS United States Department of Agriculture Animal and Plant Health Inspection Service Facebook Email Blog Home Our Focus Animal Health Animal Welfare Biotechnology Business Services Civil Rights Emergency Response Imports & Exports International Services Plant Health Science Tribal

Age 60 study, part IV : experimental evaluation of pilot performance.

DOT National Transportation Integrated Search

1994-10-01

This document is one of four products completed as a part of the Age 60 Rule Research Contract monitored by Pam Della Rocco, Civil Aerospace Medical Institute. This report was a deliverable from the research contract with Hilton Systems, Inc. on the ...

Age 60 rule research, part I : bibliographic database.

DOT National Transportation Integrated Search

1994-10-01

This document is one of four products completed as a part of the Age 60 Rule research contract monitored by Pam Della Rocco, Civil Aerospace Medical Institute. As part of their research contract with the FAA to study issues related to the "Age 60 Rul...

Using global health initiatives to strengthen health systems: a civil society perspective.

PubMed

Cohn, Jennifer; Russell, Asia; Baker, Brook; Kayongo, Alice; Wanjiku, Esther; Davis, Paul

2011-01-01

Research into the effects of global health initiatives (GHIs) on health systems has largely left out the viewpoints and contributions of civil society. This study details civil society's perspective regarding the effects of two GHIs, the US President's Emergency Plan for AIDS Relief (PEPFAR) and the Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM), on country health systems and the added value of civil society interacting with GHIs to strengthen health systems. The study employed qualitative data collection methods using semi-structured interviews administered during focus groups and key informant interviews. A range of health system stakeholders were interviewed in Kenya, Malawi, Uganda and Zambia. Data were coded and analysed for themes and sub-themes. In total, 2910 civil society participants provided information individually or in focus groups. Respondents reported that GHIs have contributed to dramatic health benefits within and outside of a disease-specific focus, including health systems strengthening efforts. However, opportunities for synergy between GHIs and health systems have been missed, and GHIs have not worked sufficiently to close capacity gaps of grassroots civil society organisations. Despite some governance innovations, civil society's opportunities to participate meaningfully in GHI priority setting efforts are limited. Recommendations are included on how to best use GHIs to strengthen health systems by partnering with civil society.

Research on reform plan of civil engineering adult education graduation design

NASA Astrophysics Data System (ADS)

Su, Zhibin; Sun, Shengnan; Cui, Shicai

2017-12-01

As for civil engineering adult education graduation design, reform program is put forward combined with our school. The main points of reform include the following aspects. New pattern of graduation design which is consisted of basic training of engineering design, technical application and engineering innovation training is formed. Integration model of graduation design and employment is carried out. Multiple professional guidance graduation design pattern is put forward. Subject of graduation design is chosen based on the school actual circumstance. A “three stage” quality monitoring system is established. Performance evaluation pattern that concludes two oral examinations of the dissertation is strictly carried out.

FRP debonding monitoring using OTDR techniques

NASA Astrophysics Data System (ADS)

Hou, Shuang; Cai, C. S. Steve; Ou, Jinping

2009-07-01

Debonding failure has been reported as the dominant failure mode for FRP strengthening in flexure. This paper explores a novel debonding monitoring method for FRP strengthened structures by means of OTDR-based fiber optic technology. Interface slip as a key factor in debonding failures will be measured through sensing optic fibers, which is instrumented in the interface between FRP and concrete in the direction perpendicular to the FRP filaments. Slip in the interface will induce power losses in the optic fiber signals at the intersection point of the FRP strip and the sensing optic fiber and the signal change will be detected through OTDR device. The FRP double shear tests and three-point bending tests were conducted to verify the effectiveness of the proposed monitoring method. It is found that the early bebonding can be detected before it causes the interface failure. The sensing optic fiber shows signal changes in the slip value at about 36~156 micrometer which is beyond sensing capacity of the conventional sensors. The tests results show that the proposed method is feasible in slip measurement with high sensitivity, and would be cost effective because of the low price of sensors used, which shows its potential of large-scale applications in civil infrastructures, especially for bridges.

ISTIMES project: status and outcomes

NASA Astrophysics Data System (ADS)

Cuomo, V.; Proto, M.; Soldovieri, F.

2012-04-01

ISTIMES is a project approved in the Seventh Framework Programme of the European Union under the Joint Call FP7-ICT-SEC-2007-1. It has a three years duration and will be completed within June 2012. According to the aims of the proposal, ISTIMES project has designed, assessed and developed a prototypical modular and scalable ICT-based system, exploiting distributed and local sensors, for non-destructive electromagnetic monitoring; the specific application field was the reliability and safety of critical transport infrastructures, even if the modularity of the ISTIMES approach has permitted to extend it successfully to other critical infrastructures as dams. The continuous and fruitful involvement of end users (as Italian Civil Protection) allowed to develop applications focused on users needs. ISTIMES couples current monitoring of infrastructures with a high situational awareness during crises management, providing updated and detailed real and near real time information about the infrastructure status to improve decision support for emergency and disasters stakeholders. The system exploits an open network architecture that can accommodate a wide range of heterogeneous sensors, static and mobile, and can be easily scaled up to allow the integration of additional sensors and interfaces with other networks. It relies on state-of-the-art electromagnetic sensors, enabling a networking of terrestrial sensors, supported by specific satellite and airborne measurements. The integration of electromagnetic technologies with new ICT information and telecommunications systems enables remotely controlled monitoring and surveillance at different temporal and spatial scales, providing indexes and images of the critical transport infrastructures. The project has exploited, assessed and improved many different non-invasive technologies based on electromagnetic sensing as: Optic Fiber Sensors, Synthetic Aperture; Radar (SAR) satellite platform; Hyperspectral Spectroscopy; Infrared Thermography; Ground Penetrating Radar; low-frequency Geophysical Techniques; ground based SAR and optical cameras for the assessment of the dynamical behaviour of the infrastructure. A great effort has been devoted to "transfer" these novel and state-of art technologies from the laboratory experience to actual on field applications by adapting/improving them and developing prototypes for the specific application domain of the monitoring of transport and critical infrastructures. Sensor synergy, data cross correlation and novel concepts of information fusion have permitted to carry out a multi-method, multi-resolution and multi-scale electromagnetic detection and monitoring of the infrastructure, including surface and subsurface aspects. The project has allowed to develop an ICT architecture based on web sensors and serviceoriented- technologies that comply with specific end-user requirements, including interoperability, economical convenience, exportability, efficiency and reliability. The efforts have focussed mainly to the creation of web based interfaces able to control "not standard" sensors, as the ones proposed in the project, and to the standardization necessary to have a full interoperability and modularity of the monitoring system. In addition, the system is able to provide a more easily accessible and transparent scheme for use by different end-users and to integrate the monitoring results and images with other kind of information such as GIS layer and historical datasets relating to the site. The ISTIMES system has been evaluated at two test sites and two test beds. At the two test sites of Montagnole rock-fall station (Chambery, France) and Hydrogeosite Laboratory (Potenza, Italy), the attention was posed to a thorough analysis of the performances of the in situ sensing techniques, by investigating, with good outcomes, also the possibility to correlate and have a synergy from the different sensors. In particular, it is worth noting that the experiment realized at Montagnole is unique, at least at European level, regarding both the high mechanical impact on a real scale elements of civil engineering structure, and also for the exploitation of all sensor techniques set up in a cooperative way. The effectiveness of the overall monitoring system has been assessed by the experiments at real test beds as Sihlhochstrasse bridge, a 1.5 km bridge representing one of the main entrance road to Zurich city (Switzerland), Varco Izzo railway tunnel and Musmeci motorway bridge located in the area of Potenza city in Basilicata region (Italy) affected by a high seismic risk. In particular, for the Musmeci bridge, the main entrance road to Potenza city and a masterpiece of architectural/civil engineering realized by Sergio Musmeci in 60' years, all the sensing technologies involved in the project have been exploited to perform a monitoring/diagnostics; the Musmeci bridge results have been correlated and tested also by the comparison with the sensors mostly used by civil engineers for this kind of infrastructures (Proto et al., 2010). Acknowledgment The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement n. 225663.

Study on the fabricating process monitoring of thermoplastic based materials packaged OFBG and their sensing properties

NASA Astrophysics Data System (ADS)

Wang, Chuan; Zhou, Zhi; Zhang, Zhichun; Ou, Jinping

2007-04-01

As common materials or engineering materials, thermoplastic resin based materials can be used not only directly fabricating products but also FRTP(fiber reinforced thermoplastic polymer) materials for other uses. As one kind of FRTP material, GFRPP(glass fiber reinforced polypropylene) has lots of merits, such as: light weight, high strength, high tenacity, high elongation percentage, good durability, reshaping character and no environmental pollution characters. And they also can be conveniently formed hoop rebar in civil engineering. While a new kind of GFRPP-OFBG smart rod which combined GFRPP and OFBG together can be used as not only structure materials but also sensing materials. Meanwhile, PP packaged OFBG strain sensor can be expected for its low modulus, good sensitivity and good durability. Furthermore, it can be used for large strain measuring. In this paper, we have successfully fabricated a new kind of GFRPP-OFBG(Glass Fiber Reinforced Polypropylene-Optic Fiber Bragg Grating) rod by our own thermoplastic pultrusion production line and a new kind of PP packaged OFBG strain sensor by extruding techniques. And we monitored the inner strain and temperature changes with tow OFBG simultaneously of the fabricating process. The results show that: OFBG can truly reflect the strain and temperature changes in both the GFRPP rod and the PP packaged OFBG, these are very useful to modify our processing parameters. And we also find that because of the shrinkage of PP, this new kind of PP packaged OFBG have -13000μɛ storage, and the strain sensing performance is still very well, so which can be used for large strain measuring. Besides these, GFRPP-OFBG smart rod has good sensing performance in strain sensing just like that of FRSP-OFBG rod, the strain sensitivity coefficient is about1.19pm/μɛ. Besides these, the surface of GFRPP-OFBG rods can be handled just as steel bars and also can be bended and reshaped. These are all very useful and very important for the use of FRP materials in civil engineering structures.

Detection of Two Buried Cross Pipelines by Observation of the Scattered Electromagnetic Field

NASA Astrophysics Data System (ADS)

Mangini, Fabio; Di Gregorio, Pietro Paolo; Frezza, Fabrizio; Muzi, Marco; Tedeschi, Nicola

2015-04-01

In this work we present a numerical study on the effects that can be observed in the electromagnetic scattering of a plane wave due to the presence of two crossed pipelines buried in a half-space occupied by cement. The pipeline, supposed to be used for water conveyance, is modeled as a cylindrical shell made of metallic or poly-vinyl chloride (PVC) material. In order to make the model simpler, the pipelines are supposed running parallel to the air-cement interface on two different parallel planes; moreover, initially we suppose that the two tubes make an angle of 90 degrees. We consider a circularly-polarized plane wave impinging normally to the interface between air and the previously-mentioned medium, which excites the structure in order to determine the most useful configuration in terms of scattered-field sensitivity. To perform the study, a commercially available simulator which implements the Finite Element Method was adopted. A preliminary frequency sweep allows us to choose the most suitable operating frequency depending on the dimensions of the commercial pipeline cross-section. We monitor the three components of the scattered electric field along a line just above the interface between the two media. The electromagnetic properties of the materials employed in this study are taken from the literature and, since a frequency-domain technique is adopted, no further approximation is needed. Once the ideal problem has been studied, i.e. having considered orthogonal and tangential scenario, we further complicate the model by considering different crossing angles and distances between the tubes, in two cases of PVC and metallic material. The results obtained in these cases are compared with those of the initial problem with the goal of determining the scattered field dependence on the geometrical characteristics of the cross between two pipelines. One of the practical applications in the field of Civil Engineering of this study may be the use of ground penetrating radar (GPR) techniques to monitor the fouling conditions of water pipelines without the need to intervene destructively on the structure. Acknowledgements: This work is a contribution to COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar".

Design and implementation of smart sensor nodes for wireless disaster monitoring systems

NASA Astrophysics Data System (ADS)

Chen, Yih-Fan; Wu, Wen-Jong; Chen, Chun-Kuang; Wen, Chih-Min; Jin, Ming-Hui; Gau, Chung-Yun; Chang, Chih-Chie; Lee, Chih-Kung

2004-07-01

A newly developed smart sensor node that can monitor the safety of temporary structures such as scaffolds at construction sites is detailed in this paper. The design methodology and its trade-offs, as well as its influence on the optimization of sensor networks, is examined. The potential impact on civil engineering construction sites, environmental and natural disaster pre-warning issues, etc., all of which are foundations of smart sensor nodes and corresponding smart sensor networks, is also presented. To minimize the power requirements in order to achieve a true wireless system both in terms of signal and power, a sensor node was designed by adopting an 8051-based micro-controller, an ISM band RF transceiver, and an auto-balanced strain gage signal conditioner. With the built-in RF transceiver, all measurement data can be transmitted to a local control center for data integrity, security, central monitoring, and full-scale analysis. As a battery is the only well-established power source and there is a strong desire to eliminate the need to install bulky power lines, this system designed includes a battery-powered core with optimal power efficiency. To further extend the service life of the built-in power source, a power control algorithm has been embedded in the microcontroller of each sensor node. The entire system has been verified by experimental tests on full-scale scaffold monitoring. The results show that this system provides a practical method to monitor the structure safety in real time and possesses the potential of reducing maintenance costs significantly. The design of the sensor node, central control station, and the integration of several kinds of wireless communication protocol, all of which are successfully integrated to demonstrate the capabilities of this newly developed system, are detailed. Potential impact to the network topology is briefly examined as well.

From theoretical fixed return period events to real flooding impacts: a new approach to set flooding scenarios, thresholds and alerts

NASA Astrophysics Data System (ADS)

Parravicini, Paola; Cislaghi, Matteo; Condemi, Leonardo

2017-04-01

ARPA Lombardia is the Environmental Protection Agency of Lombardy, a wide region in the North of Italy. ARPA is in charge of river monitoring either for Civil Protection or water balance purposes. It cooperates with the Civil Protection Agency of Lombardy (RL-PC) in flood forecasting and early warning. The early warning system is based on rainfall and discharge thresholds: when a threshold exceeding is expected, RL-PC disseminates an alert from yellow to red. The conventional threshold evaluation is based on events at a fixed return period. Anyway, the impacts of events with the same return period may be different along the river course due to the specific characteristics of the affected areas. A new approach is introduced. It defines different scenarios, corresponding to different flood impacts. A discharge threshold is then associated to each scenario and the return period of the scenario is computed backwards. Flood scenarios are defined in accordance with National Civil Protection guidelines, which describe the expected flood impact and associate a colour to the scenario from green (no relevant effects) to red (major floods). A range of discharges is associated with each scenario since they cause the same flood impact; the threshold is set as the discharge corresponding to the transition between two scenarios. A wide range of event-based information is used to estimate the thresholds. As first guess, the thresholds are estimated starting from hydraulic model outputs and the people or infrastructures flooded according to the simulations. Eventually the model estimates are validated with real event knowledge: local Civil Protection Emergency Plans usually contain very detailed local impact description at known river levels or discharges, RL-PC collects flooding information notified by the population, newspapers often report flood events on web, data from the river monitoring network provide evaluation of actually happened levels and discharges. The methodology allows to give a return period for each scenario. The return period may vary along the river course according to the discharges associated with the scenario. The values of return period may show the areas characterized by higher risk and can be an important basis for civil protection emergency planning and river monitoring. For example, considering the Lambro River, the red scenario (major flood) shows a return period of 50 years in the northern rural part of the catchment. When the river crosses the city of Milan, the return period drops to 4 years. Afterwards it goes up to more than 100 years when the river flows in the agricultural areas in the southern part of the catchment. In addition, the knowledge gained with event-based analysis allows evaluating the compliance of the monitoring network with early warning requirements and represents the starting point for further development of the network itself.

MAppERS: a peer-produced community for emergency support

NASA Astrophysics Data System (ADS)

Frigerio, Simone; Schenato, Luca; Bianchizza, Chiara; Del Bianco, Daniele

2014-05-01

A general trend in European governance tends to shift responsibilities in territorial management from national central authorities to local/regional levels and to the citizens as first actors of Civil Protection. Prevention is a long term goal that rests not only on the capacities of professional operators and volunteers, but that has to necessarily imply the involvement and awareness of the citizens over the territory they inhabit. In fact people often do not have chance to interact in the surveillance of the territory and only face risks when they have to bear impacts on their lives. Involvement of population creates more cost-effective and context-specific strategies of territorial surveillance and management. A collaborative user environment is useful for emergency response and support in the wake of disasters, feeding updated information on the ground directly to on-site responders. MAppERS (Mobile Application for Emergency Response and Support) is a EU project (funded under programme 2013-2015 Humanitarian Aid and Civil Protection, ECHO A5) which empowers citizens as "crowd-sourced mappers" through the development of a smart phone application able to collect GPS-localised and detailed parameters, that can then be sent from citizens to civil protection operators in a contest of geospatial response. The process of app design includes feedback from citizens, involving them in training courses on the monitoring of the territory as long term objective of raising public awareness and participation from the citizens, as actors in a networked disaster response community. The project proceeds from the design and testing of the smart phone applications (module MAppERS-V for volunteers, module MAppERS-C for citizens) according to software engineering environment (Android and Iphone SDK). Information exchange and data transfer need clearness and efficiency; thus a previous research is conducted on the cost-effectiveness of already existing practices for territorial management. Citizens and volunteers of civil protection are then involved to test applications at pilot sites. This phase takes place in parallel to a dedicated training on app functioning. The app modules are to be later re-designed according to a methodological and technical feedback gained during pilot study. Training curricula for citizens that wish to be involved in the monitoring of the territory in the long run are then to be defined so to promote territorial knowledge and awareness, give information and practical skills on smart phone technologies and specific efficient jargon to communicate hazard relevant information. Overall, a user-friendly integration with existing monitoring on-site technique prevails on a deep new architecture. A synchronized platform would allow both the protection of private data from citizens and the identification of the users in case of misuse of the information sharing. The expected results of this project are: a) an easy-to-use "human-data" input on crisis management, b) the development of a multi-module smart phone application linking trained people and headquarters c) maximised utility of peer-produced mapping (e.g. damaged points, critical hotspots), d) the development of a strategy of disaster prevention based on development of human and social resources rather than structural mitigation options.

Microtremors for seismic response assessments of important modern and historical structures of Crete

NASA Astrophysics Data System (ADS)

Margarita, Moisidi; Filippos, Vallianatos

2017-12-01

Strengthening seismic risk resilience undertaken by the civil protection authorities is an important issue towards to the guidelines given by Sendai Framework, 2013 European Union Civil Protection legislation and the global agenda 2030 for sustainable development. Moreover, in recent years it has been emphasized that site effect specifications are important issues for the seismic hazard assessments of modern, historical and monumental structures. This study assess the frequencies of vibration of historical, monumental and modern structures in the cities of Chania, Rethymno and Heraklion of Crete using ambient noise recordings processed through the Horizontal to Vertical spectral ratio and examines potential soil-structure interaction phenomena. Examples of the seismic response of high rise structures such as a church bell tower and the lighthouses in Chania are presented.

Recent enhancements to and applications of the SmartBrick structural health monitoring platform

NASA Astrophysics Data System (ADS)

Gunasekaran, A.; Cross, S.; Patel, N.; Sedigh, S.

2012-04-01

The SmartBrick network is an autonomous and wireless solution for structural health monitoring of civil infrastructures. The base station is currently in its third generation and has been laboratory- and field-tested in the United States and Italy. The second generation of the sensor nodes has been laboratory-tested as of publication. In this paper, we present recent enhancements made to hardware and software of the SmartBrick platform. Salient improvements described include the development of a new base station with fully-integrated long-range GSM (cellular) and short-range ZigBee communication. The major software improvement described in this paper is migration to the ZigBee PRO stack, which was carried out in the interest of interoperability. To broaden the application of the platform to critical environments that require survivability and fault tolerance, we have striven to achieve compliance with military standards in the areas of hardware, software, and communication. We describe these efforts and present a survey of the military standards investigated. Also described is instrumentation of a three-span experimental bridge in Washington County, Missouri; with the SmartBrick platform. The sensors, whose output is conditioned and multiplexed; include strain gauges, thermocouples, push potentiometers, and three-axis inclinometers. Data collected is stored on site and reported over the cellular network. Real-time alerts are generated if any monitored parameter falls outside its acceptable range. Redundant sensing and communication provide reliability and facilitate corroboration of the data collected. A web interface is used to issue remote configuration commands and to facilitate access to and visualization of the data collected.

Nonlinear finite element model updating for damage identification of civil structures using batch Bayesian estimation

NASA Astrophysics Data System (ADS)

Ebrahimian, Hamed; Astroza, Rodrigo; Conte, Joel P.; de Callafon, Raymond A.

2017-02-01

This paper presents a framework for structural health monitoring (SHM) and damage identification of civil structures. This framework integrates advanced mechanics-based nonlinear finite element (FE) modeling and analysis techniques with a batch Bayesian estimation approach to estimate time-invariant model parameters used in the FE model of the structure of interest. The framework uses input excitation and dynamic response of the structure and updates a nonlinear FE model of the structure to minimize the discrepancies between predicted and measured response time histories. The updated FE model can then be interrogated to detect, localize, classify, and quantify the state of damage and predict the remaining useful life of the structure. As opposed to recursive estimation methods, in the batch Bayesian estimation approach, the entire time history of the input excitation and output response of the structure are used as a batch of data to estimate the FE model parameters through a number of iterations. In the case of non-informative prior, the batch Bayesian method leads to an extended maximum likelihood (ML) estimation method to estimate jointly time-invariant model parameters and the measurement noise amplitude. The extended ML estimation problem is solved efficiently using a gradient-based interior-point optimization algorithm. Gradient-based optimization algorithms require the FE response sensitivities with respect to the model parameters to be identified. The FE response sensitivities are computed accurately and efficiently using the direct differentiation method (DDM). The estimation uncertainties are evaluated based on the Cramer-Rao lower bound (CRLB) theorem by computing the exact Fisher Information matrix using the FE response sensitivities with respect to the model parameters. The accuracy of the proposed uncertainty quantification approach is verified using a sampling approach based on the unscented transformation. Two validation studies, based on realistic structural FE models of a bridge pier and a moment resisting steel frame, are performed to validate the performance and accuracy of the presented nonlinear FE model updating approach and demonstrate its application to SHM. These validation studies show the excellent performance of the proposed framework for SHM and damage identification even in the presence of high measurement noise and/or way-out initial estimates of the model parameters. Furthermore, the detrimental effects of the input measurement noise on the performance of the proposed framework are illustrated and quantified through one of the validation studies.

Structural analysis for preliminary design of High Speed Civil Transport (HSCT)

NASA Technical Reports Server (NTRS)

Bhatia, Kumar G.

1992-01-01

In the preliminary design environment, there is a need for quick evaluation of configuration and material concepts. The simplified beam representations used in the subsonic, high aspect ratio wing platform are not applicable for low aspect ratio configurations typical of supersonic transports. There is a requirement to develop methods for efficient generation of structural arrangement and finite element representation to support multidisciplinary analysis and optimization. In addition, empirical data bases required to validate prediction methods need to be improved for high speed civil transport (HSCT) type configurations.

47 CFR 27.1180 - The cost-sharing formula.

Code of Federal Regulations, 2010 CFR

2010-10-01

...); towers and/or modifications; back-up power equipment; monitoring or control equipment; engineering costs (design/path survey); installation; systems testing; FCC filing costs; site acquisition and civil works... as equipment and engineering expenses. There is no cap on the actual costs of relocation. (c) An AWS...

ATLANTA COMMUTE VEHICLE SOAK AND START DISTRIBUTIONS AND ENGINE STARTS PER DAY: IMPACT ON MOBILE SOURCE EMISSION RATES

EPA Science Inventory

Georgia Institute of Technology School of Civil and Environmental Engineering researchers analyzed the 2004 vehicle activity data obtained from vehicles in the Atlanta Commuter Choice Value Pricing Initiative. The onboard monitoring equipment installed in each participating vehi...

Seismology in civil engineering

NASA Astrophysics Data System (ADS)

Dvorak, A.

Properties of soils and rocks exposed to vibrations in the practice of civil engineering are examined. Seismic and dynamic field investigations, determination of seismic and dynamic modulus of elasticity, coefficients of damping and absorption are studied. Seismic effects of blasting and of other sources of vibrations on structures and persons, application of rock-noise and dynamic tests of piles are studied.

Islamic Fatalism and the Clash of Civilizations: An Appraisal of a Contentious and Dubious Theory

ERIC Educational Resources Information Center

Acevedo, Gabriel A.

2008-01-01

This paper will address the question of Islamic fatalism. Survey data will be used to assess Samuel P. Huntington's controversial "Clash of Civilizations" thesis and its emphasis on fatalism as an inherent characteristic of Islamic religion. The concept of fatalism is expanded and theorized as a function of both structural and…

Culture Matters--The Training of Senior Civil Servants in Austria, Germany, the Netherlands and Switzerland

ERIC Educational Resources Information Center

Knassmüller, Monika; Veit, Sylvia

2016-01-01

Senior civil servants (SCS) are powerful actors with great responsibilities in the field of policymaking and management. Due to public sector reforms that are New Public Management oriented, specialised education and structured training programmes for (future) SCS as well as fast-track systems for high-potential employees have become increasingly…

The Supreme Court, Civil Rights, and Preference Policies: Judicial Decision Making Processes in the United States and India.

ERIC Educational Resources Information Center

Parikh, Sunita

1990-01-01

Presents a comparative analysis of the U.S. and Indian Supreme Courts' roles in civil rights and preference policies. Despite structural and historical differences, similarities exist in the development of such policies. Both are more concerned with fidelity to constitutional and statutory interpretations than to personal ideological viewpoints.…

Ground Control Point - Wireless System Network for UAV-based environmental monitoring applications

NASA Astrophysics Data System (ADS)

Mejia-Aguilar, Abraham

2016-04-01

In recent years, Unmanned Aerial Vehicles (UAV) have seen widespread civil applications including usage for survey and monitoring services in areas such as agriculture, construction and civil engineering, private surveillance and reconnaissance services and cultural heritage management. Most aerial monitoring services require the integration of information acquired during the flight (such as imagery) with ground-based information (such as GPS information or others) for improved ground truth validation. For example, to obtain an accurate 3D and Digital Elevation Model based on aerial imagery, it is necessary to include ground-based information of coordinate points, which are normally acquired with surveying methods based on Global Position Systems (GPS). However, GPS surveys are very time consuming and especially for longer time series of monitoring data repeated GPS surveys are necessary. In order to improve speed of data collection and integration, this work presents an autonomous system based on Waspmote technologies build on single nodes interlinked in a Wireless Sensor Network (WSN) star-topology for ground based information collection and later integration with surveying data obtained by UAV. Nodes are designed to be visible from the air, to resist extreme weather conditions with low-power consumption. Besides, nodes are equipped with GPS as well as Inertial Measurement Unit (IMU), accelerometer, temperature and soil moisture sensors and thus provide significant advantages in a broad range of applications for environmental monitoring. For our purpose, the WSN transmits the environmental data with 3G/GPRS to a database on a regular time basis. This project provides a detailed case study and implementation of a Ground Control Point System Network for UAV-based vegetation monitoring of dry mountain grassland in the Matsch valley, Italy.

Nurse Leaders' Response to Civil Unrest in the Urban Core

PubMed Central

Goodwin Veenema, Tener; Calvert, Wilma J.; Grigsby, Sheila R.; Cobbina, Jennifer

2017-01-01

Inequalities in society, culture, and finance have resulted in civil unrest, rioting, and intentional violence throughout our history. Nowhere is this currently more apparent than in the cities of Ferguson and Baltimore. It is not the civil unrest itself, but the resulting rioting and intentional violence that can create a disaster situation. This increases the care burden of health care providers during times when the governmental structure may be overwhelmed or functioning in a less than optimal manner. Beginning with the death of Michael Brown, civil unrest over the last 2 years has necessitated a closer examination of the role nurse leaders play in preparing their staff and facilities for potential results of this civil unrest. The similarities between the results of rioting and violence and natural disaster are obvious, but the differences are significant. Without adequate preparation, providers may not offer the appropriate response. Attention to the 10 “musts” for preparedness for civil unrest will facilitate a planning process and provide for a better response and recovery when communities face these issues. PMID:28263274

Restoration of the USS Monitor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krop, David

2010-03-02

David Krop will discuss the ongoing efforts to conserve and exhibit the iconic Civil War ironclad USS Monitor at The Mariners' Museum. The presentation will cover past conservation accomplishments by conservators and NOAA specialists, current activities in the lab, and future plans to bring back to life one of the world's most famous warships. Learn about the complex methods and procedures used to treat the ship's revolving gun turret, steam engine, Dahlgren guns and carriages, as well as numerous small artifacts like personal items from the crew.

COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar": ongoing research activities and third-year results

NASA Astrophysics Data System (ADS)

Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Tosti, Fabio

2016-04-01

This work aims at disseminating the ongoing research activities and third-year results of the COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar." About 350 experts are participating to the Action, from 28 COST Countries (Austria, Belgium, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Malta, Macedonia, The Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom), and from Albania, Armenia, Australia, Colombia, Egypt, Hong Kong, Jordan, Israel, Philippines, Russia, Rwanda, Ukraine, and United States of America. In September 2014, TU1208 has been recognised among the running Actions as "COST Success Story" ("The Cities of Tomorrow: The Challenges of Horizon 2020," September 17-19, 2014, Torino, IT - A COST strategic workshop on the development and needs of the European cities). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of buried objects, shape-reconstruction and estimation of geophysical parameters useful for civil engineering needs; (iv) networking for the design, realization and optimization of innovative GPR equipment; (v) comparing GPR with different NDT techniques, such as ultrasonic, radiographic, liquid-penetrant, magnetic-particle, acoustic-emission and eddy-current testing; (vi) comparing GPR technology and methodology used in civil engineering with those used in other fields; (vii) promotion of a more widespread, advanced and efficient use of GPR in civil engineering; and (viii) organization of a high-level modular training program for GPR European users. Four Working Groups (WGs) carry out the research activities. WG 1 focuses on the design of innovative GPR equipment, on the building of prototypes and on the testing and optimisation of new systems. WG 2 focuses on the GPR surveying of pavement, bridges, tunnels and buildings, as well as on the sensing of underground utilities and voids. WG 3 deals with the development of electromagnetic forward and inverse scattering methods, for the characterization of GPR scenarios, as well as with data-processing algorithms for the elaboration of the data collected during GPR surveys. WG 4 works on the use of GPR in fields different from the civil engineering, as well as on the integration of GPR with other non-destructive testing techniques. Each WG includes several Projects. COST Action TU1208 is active through a range of networking tools: meetings, workshops, conferences, training schools, short-term scientific missions, dissemination activities. For more information on COST Action TU1208, please visit www.GPRadar.eu and www.cost.eu. Acknowledgement The Authors wish to thank COST, for funding the COST Action TU1208 "Civil engineering applications of Ground Penetrating Radar."

Instrumentation by distributed optical fiber sensors of a new ballastless track structure

NASA Astrophysics Data System (ADS)

Chapeleau, Xavier; Cottineau, Louis-Marie; Sedran, Thierry; Gueguen, Ivan; Cailliau, Joël

2013-04-01

While relatively expensive to build, ballastless track structures are presently seen as an attractive alternative to conventional ballast. With its service life of at least 60 years, they require little maintenance and hence they offer great availability. Other reasons for using ballastless tracks instead of ballasted tracks are the lack of suitable ballast material and the need of less noise and vibration for high-speed, in particularly. A new ballastless track structure has been designed to be circulated up to 300km/h, with a target life of 100 years. It is an interoperable way on concrete slabs that are cast-in-place and slip formed. This structure has been built and tested at the scale one in our laboratory. Indeed, ten millions cyclic loads were applied at 2.5Hz to evaluate the fatigue behaviour under selected mechanical and thermal conditions. To monitor the thermo-mechanical behavior of this new structure and to verify the numerical simulations used for its design, a lot of sensors have been embedded. In particularly, we have tested an optical fiber as distributed sensors to measure strain distribution in the railway model. This sensor can also be used to detect, localize and monitor cracks in concrete slabs. The optical fiber sensing technique ("Rayleigh technique") used in this experimentation has a centimetric spatial resolution which allows to measure complex strain profiles unlike electrical strain gauges which only give local information. Firstly, optical cables used as sensors have been successfully embedded and attached to the reinforcing steel bars in the structure. We have noted that they are resistant enough to resist concrete pouring and working activities. Secondly, strains measured by conventional strain gauges has confirmed the quality of the strain profiles measurements obtained by optical fiber sensors. Moreover, we have found a good agreement between experimental profiles measurements and those obtained by numerical simulations. Early during the fatigue test, some cracks have been observed. It is a current phenomenon in concrete slab which is due to drying shrinkage, load action, environmental factors and creep of concrete. Cracks can reduce the durability of the tract structure. So, it is important to be able to monitor them during the service of ballastless track line. We have demonstrated that cracks can detect, localized and monitor by a judicious placement of optical fibers. A crack corresponds to the appearance of a narrow peak on the strain profile. This peak can be detected and localized thanks to the very high spatial resolution of the optical Rayleigh sensing technique. Thus, we have noted that the cracks remain localized in slab edge without affecting the mechanical performances of the ballastless track structure. In conclusion, distributed sensing based on optical fiber sensor is a promising technique to monitor ballastless track structures and more generally, civil engineering structures. Some tests on a portion of a ballastless track line (still under construction) are planned in the next month.

Space Weather Research in Armenia

NASA Astrophysics Data System (ADS)

Chilingarian, A. A.

DVIN for ASEC (Data Visualization interactive Network for Aragats Space Environmental Center) is product for accessing and analysis the on-line data from Solar Monitors located at high altitude research station on Mt. Aragats in Armenia. Data from ASEC monitors is used worldwide for scientific purposes and for monitoring of severe solar storms in progress. Alert service, based on the automatic analysis of variations of the different species of cosmic ray particles is available for subscribers. DVIN advantages: DVIN is strategically important as a scientific application to help develop space science and to foster global collaboration in forecasting potential hazards of solar storms. It precisely fits with the goals of the new evolving information society to provide long-term monitoring and collection of high quality scientific data, and enables adequate dialogue between scientists, decision makers, and civil society. The system is highly interactive and exceptional information is easily accessible online. Data can be monitored and analyzed for desired time spans in a fast and reliable manner. The ASEC activity is an example of a balance between the scientific independence of fundamental research and the needs of civil society. DVIN is also an example of how scientific institutions can apply the newest powerful methods of information technologies, such as multivariate data analysis, to their data and also how information technologies can provide convenient and reliable access to this data and to new knowledge for the world-wide scientific community. DVIN provides very wide possibilities for sharing data and sending warnings and alerts to scientists and other entities world-wide, which have fundamental and practical interest in knowing the space weather conditions.

Advanced materials and techniques for fibre-optic sensing

NASA Astrophysics Data System (ADS)

Henderson, Philip J.

2014-06-01

Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company - a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. Keywords: Fibre-optic sensors, fibre Bragg gratings, MEMS, MOEMS, nanotechnology, plasmon.

Acoustic emission characterization of microcracking in laboratory-scale hydraulic fracturing tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hampton, Jesse; Gutierrez, Marte; Matzar, Luis

Understanding microcracking near coalesced fracture generation is critically important for hydrocarbon and geothermal reservoir characterization as well as damage evaluation in civil engineering structures. Dense and sometimes random microcracking near coalesced fracture formation alters the mechanical properties of the nearby virgin material. Individual microcrack characterization is also significant in quantifying the material changes near the fracture faces (i.e. damage). Acoustic emission (AE) monitoring and analysis provide unique information regarding the microcracking process temporally, and information concerning the source characterization of individual microcracks can be extracted. In this context, laboratory hydraulic fracture tests were carried out while monitoring the AEs frommore » several piezoelectric transducers. In-depth post-processing of the AE event data was performed for the purpose of understanding the individual source mechanisms. Several source characterization techniques including moment tensor inversion, event parametric analysis, and volumetric deformation analysis were adopted. Post-test fracture characterization through coring, slicing and micro-computed tomographic imaging was performed to determine the coalesced fracture location and structure. Distinct differences in fracture characteristics were found spatially in relation to the openhole injection interval. Individual microcrack AE analysis showed substantial energy reduction emanating spatially from the injection interval. Lastly, it was quantitatively observed that the recorded AE signals provided sufficient information to generalize the damage radiating spatially away from the injection wellbore.« less

Acoustic emission characterization of microcracking in laboratory-scale hydraulic fracturing tests

DOE PAGES

Hampton, Jesse; Gutierrez, Marte; Matzar, Luis; ...

2018-06-11

Understanding microcracking near coalesced fracture generation is critically important for hydrocarbon and geothermal reservoir characterization as well as damage evaluation in civil engineering structures. Dense and sometimes random microcracking near coalesced fracture formation alters the mechanical properties of the nearby virgin material. Individual microcrack characterization is also significant in quantifying the material changes near the fracture faces (i.e. damage). Acoustic emission (AE) monitoring and analysis provide unique information regarding the microcracking process temporally, and information concerning the source characterization of individual microcracks can be extracted. In this context, laboratory hydraulic fracture tests were carried out while monitoring the AEs frommore » several piezoelectric transducers. In-depth post-processing of the AE event data was performed for the purpose of understanding the individual source mechanisms. Several source characterization techniques including moment tensor inversion, event parametric analysis, and volumetric deformation analysis were adopted. Post-test fracture characterization through coring, slicing and micro-computed tomographic imaging was performed to determine the coalesced fracture location and structure. Distinct differences in fracture characteristics were found spatially in relation to the openhole injection interval. Individual microcrack AE analysis showed substantial energy reduction emanating spatially from the injection interval. Lastly, it was quantitatively observed that the recorded AE signals provided sufficient information to generalize the damage radiating spatially away from the injection wellbore.« less

Virtual Environments for Visualizing Structural Health Monitoring Sensor Networks, Data, and Metadata.

PubMed

Napolitano, Rebecca; Blyth, Anna; Glisic, Branko

2018-01-16

Visualization of sensor networks, data, and metadata is becoming one of the most pivotal aspects of the structural health monitoring (SHM) process. Without the ability to communicate efficiently and effectively between disparate groups working on a project, an SHM system can be underused, misunderstood, or even abandoned. For this reason, this work seeks to evaluate visualization techniques in the field, identify flaws in current practices, and devise a new method for visualizing and accessing SHM data and metadata in 3D. More precisely, the work presented here reflects a method and digital workflow for integrating SHM sensor networks, data, and metadata into a virtual reality environment by combining spherical imaging and informational modeling. Both intuitive and interactive, this method fosters communication on a project enabling diverse practitioners of SHM to efficiently consult and use the sensor networks, data, and metadata. The method is presented through its implementation on a case study, Streicker Bridge at Princeton University campus. To illustrate the efficiency of the new method, the time and data file size were compared to other potential methods used for visualizing and accessing SHM sensor networks, data, and metadata in 3D. Additionally, feedback from civil engineering students familiar with SHM is used for validation. Recommendations on how different groups working together on an SHM project can create SHM virtual environment and convey data to proper audiences, are also included.

Virtual Environments for Visualizing Structural Health Monitoring Sensor Networks, Data, and Metadata

PubMed Central

Napolitano, Rebecca; Blyth, Anna; Glisic, Branko

2018-01-01

Visualization of sensor networks, data, and metadata is becoming one of the most pivotal aspects of the structural health monitoring (SHM) process. Without the ability to communicate efficiently and effectively between disparate groups working on a project, an SHM system can be underused, misunderstood, or even abandoned. For this reason, this work seeks to evaluate visualization techniques in the field, identify flaws in current practices, and devise a new method for visualizing and accessing SHM data and metadata in 3D. More precisely, the work presented here reflects a method and digital workflow for integrating SHM sensor networks, data, and metadata into a virtual reality environment by combining spherical imaging and informational modeling. Both intuitive and interactive, this method fosters communication on a project enabling diverse practitioners of SHM to efficiently consult and use the sensor networks, data, and metadata. The method is presented through its implementation on a case study, Streicker Bridge at Princeton University campus. To illustrate the efficiency of the new method, the time and data file size were compared to other potential methods used for visualizing and accessing SHM sensor networks, data, and metadata in 3D. Additionally, feedback from civil engineering students familiar with SHM is used for validation. Recommendations on how different groups working together on an SHM project can create SHM virtual environment and convey data to proper audiences, are also included. PMID:29337877

77 FR 70205 - Agency Information Collection Activities: Request for Comments for a New Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-23

... CONTACT: Joyce Gottlieb, 202-366-3664, Office of Civil Rights, Federal Highway Administration, Department..., women, and non-minorities in specific highway construction job categories. This information is reported... monitor the contractors-employment and training of minorities and women in the traditional highway...

The Enforcement of University Patent Policies: A Legal Perspective.

ERIC Educational Resources Information Center

Stopp, Margaret T.; Stopp, G. Harry, Jr.

1992-01-01

Federal civil litigation in which a faculty inventor challenged the university's right to share in proceeds from his invention is examined. Issues of employment contracts, the university research office's responsibility for monitoring faculty research, and the role of patenting and licensing firms are considered. Implications for university policy…

Rangeland resource assessment, monitoring, and management using unmanned aerial vehicle-based remote sensing

USDA-ARS?s Scientific Manuscript database

Civilian applications of Unmanned Aerial Vehicles (UAV) have rapidly been expanding recently. Thanks to military development many civil UAVs come via the defense sector. Although numerous UAVs can perform civilian tasks, the regulations imposed by FAA in the national airspace system and military e...

From Dakar to Brasilia: Monitoring UNESCO's Education Goals

ERIC Educational Resources Information Center

Neri, Marcelo; Buchmann, Gabriel

2008-01-01

Active participation of Brazilian civil society, coupled with the 2007 education development plan launched by the Brazilian government, provides an interesting example of the influences of the Dakar Goals. The two domestic initiatives share the same name, spirit and direction proposed in Dakar 2000. Here we analyze changes in the Brazilian…

Designs and Technology Requirements for Civil Heavy Lift Rotorcraft

NASA Technical Reports Server (NTRS)

Johnson, Wayne; Yamauchi, Gloria K.; Watts, Michael E.

2006-01-01

The NASA Heavy Lift Rotorcraft Systems Investigation examined in depth several rotorcraft configurations for large civil transport, designed to meet the technology goals of the NASA Vehicle Systems Program. The investigation identified the Large Civil Tiltrotor as the configuration with the best potential to meet the technology goals. The design presented was economically competitive, with the potential for substantial impact on the air transportation system. The keys to achieving a competitive aircraft were low drag airframe and low disk loading rotors; structural weight reduction, for both airframe and rotors; drive system weight reduction; improved engine efficiency; low maintenance design; and manufacturing cost comparable to fixed-wing aircraft. Risk reduction plans were developed to provide the strategic direction to support a heavy-lift rotorcraft development. The following high risk areas were identified for heavy lift rotorcraft: high torque, light weight drive system; high performance, structurally efficient rotor/wing system; low noise aircraft; and super-integrated vehicle management system.

ARPA LOMBARDIA river gauging network: a great daily effort

NASA Astrophysics Data System (ADS)

Cislaghi, Matteo; Calabrese, Michele; Condemi, Leonardo; Di Priolo, Sara; Parravicini, Paola; Rondanini, Chiara; Russo, Michele; Cazzuli, Orietta; Mussin, Mauro; Serra, Roberto

2017-04-01

ARPA Lombardia is the Environmental Protection Agency of Lombardy, a wide region in northern Italy. ARPA is in charge of river monitoring either for Civil Protection or water balance purposes. Lombardy is characterized by a very complex territory; rivers start from the alpine areas and end in the Po river plain. Each mountain or plain area has specific hydrological features that has to be considered when planning a monitoring network. Moreover, human activities (such as lake regulation, agriculture diversions, hydropower plants with regulation structure etc) add anthropic interferences on the natural river system and can invalidate the collected data. In the last 10 years ARPA performed a major revision of the river gauging network. Each station was analysed using well defined criteria based on the required information (water balance or flood monitoring) and on the suitability of the gauging site (hydraulic characteristic or accessibility for spot measures). In the end more than 30% of the network was revised, many stations were closed and other installed. Particular attention was given to the discharge estimation. Many sites are characterized by backflow effect due to river confluences or to hydropower plants with water regulation structures. In these cases the classic rating curve approach can not be applied. Thus, for the first time in Italy, water velocity side looking doppler sensors were installed on natural rivers and the discharge is estimated with the index velocity method. The Italian Civil Protection Agency requires high transmission standards. No data can be lost for transmission failures and data has to be available every 30 minutes. For these reasons ARPA implemented a double transmission system: the first is based on the existing GPRS network managed by private operators, the second is based on a radio network directly installed by ARPA and totally dedicated to data transmission. This double approach ensures a very robust transmission and it allows ARPA to collect and publish data every 10 minutes. ARPA also decided to freely publish all hydrological data on its web site (http://idro.arpalombardia.it). Since 2010 either real time data or historical long series have been made available to everyone over a webgis platform. Every day ARPA employs check if the network is working correctly and validate the data. The aim is to follow the whole process of data management from its collection on the field to its open publication; this requires a great daily effort from the people in charge of the network maintenance.

Satellite imagery-based monitoring of archaeological site damage in the Syrian civil war

PubMed Central

Laugier, Elise Jakoby

2017-01-01

Since the start of the Syrian civil war in 2011, the rich archaeological heritage of Syria and northern Iraq has faced severe threats, including looting, combat-related damage, and intentional demolition of monuments. However, the inaccessibility of the conflict zone to archaeologists or cultural heritage specialists has made it difficult to produce accurate damage assessments, impeding efforts to develop mitigation strategies and policies. This paper presents results of a project, undertaken in collaboration with the American Schools of Oriental Research (ASOR) and the US Department of State, to monitor damage to archaeological sites in Syria, northern Iraq, and southern Turkey using recent, high-resolution satellite imagery. Leveraging a large database of archaeological and heritage sites throughout the region, as well as access to continually updated satellite imagery from DigitalGlobe, this project has developed a flexible and efficient methodology to log observations of damage in a manner that facilitates spatial and temporal queries. With nearly 5000 sites carefully evaluated, analysis reveals unexpected patterns in the timing, severity, and location of damage, helping us to better understand the evolving cultural heritage crisis in Syria and Iraq. Results also offer a model for future remote sensing-based archaeological and heritage monitoring efforts in the Middle East and beyond. PMID:29190783

ASI-Sistema Rischio Vulcanico SRV: a pilot project to develop EO data processing modules and products for volcanic activity monitoring based on Italian Civil Protection Department requirements and needs

NASA Astrophysics Data System (ADS)

Buongiorno, Maria Fabrizia; Musacchio, Massimo; Silvestri, Malvina; Spinetti, Claudia; Corradini, Stefano; Lombardo, Valerio; Merucci, Luca; Sansosti, Eugenio; Pugnagli, Sergio; Teggi, Sergio; Pace, Gaetano; Fermi, Marco; Zoffoli, Simona

2007-10-01

The Project called Sistema Rischio Vulcanico (SRV) is funded by the Italian Space Agency (ASI) in the frame of the National Space Plan 2003-2005 under the Earth Observations section for natural risks management. The SRV Project is coordinated by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) which is responsible at national level for the volcanic monitoring. The objective of the project is to develop a pre-operative system based on EO data and ground measurements integration to support the volcanic risk monitoring of the Italian Civil Protection Department which requirements and need are well integrated in the GMES Emergency Core Services program. The project philosophy is to implement, by incremental versions, specific modules which allow to process, store and visualize through Web GIS tools EO derived parameters considering three activity phases: 1) knowledge and prevention; 2) crisis; 3) post crisis. In order to combine effectively the EO data and the ground networks measurements the system will implement a multi-parametric analysis tool, which represents and unique tool to analyze contemporaneously a large data set of data in "near real time". The SRV project will be tested his operational capabilities on three Italian Volcanoes: Etna,Vesuvio and Campi Flegrei.

Satellite imagery-based monitoring of archaeological site damage in the Syrian civil war.

PubMed

Casana, Jesse; Laugier, Elise Jakoby

2017-01-01

Since the start of the Syrian civil war in 2011, the rich archaeological heritage of Syria and northern Iraq has faced severe threats, including looting, combat-related damage, and intentional demolition of monuments. However, the inaccessibility of the conflict zone to archaeologists or cultural heritage specialists has made it difficult to produce accurate damage assessments, impeding efforts to develop mitigation strategies and policies. This paper presents results of a project, undertaken in collaboration with the American Schools of Oriental Research (ASOR) and the US Department of State, to monitor damage to archaeological sites in Syria, northern Iraq, and southern Turkey using recent, high-resolution satellite imagery. Leveraging a large database of archaeological and heritage sites throughout the region, as well as access to continually updated satellite imagery from DigitalGlobe, this project has developed a flexible and efficient methodology to log observations of damage in a manner that facilitates spatial and temporal queries. With nearly 5000 sites carefully evaluated, analysis reveals unexpected patterns in the timing, severity, and location of damage, helping us to better understand the evolving cultural heritage crisis in Syria and Iraq. Results also offer a model for future remote sensing-based archaeological and heritage monitoring efforts in the Middle East and beyond.

EDITORIAL: Adaptive and active materials: Selected papers from the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 10) (Philadelphia, PA, USA, 28 September-1 October 2010) Adaptive and active materials: Selected papers from the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 10) (Philadelphia, PA, USA, 28 September-1 October 2010)

NASA Astrophysics Data System (ADS)

Brei, Diann

2011-09-01

The third annual meeting of the AMSE/AIAA Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) took place in the heart of historic Philadelphia's cultural district, and included a pioneer banquet in the National Constitutional Center. The applications emphasis of the 2010 conference was reflected in keynote talks by Dr Alan Taub, vice president of General Motors global research and development, 'Smart materials in the automotive industry'; Dr Charles R Farrar, engineering institute leader at Los Alamos National Laboratory, 'Future directions for structural health monitoring of civil engineering infrastructure'; and Professor Christopher S Lynch of the University of California Los Angeles, 'Ferroelectric materials and their applications'. The SMASIS conference was divided into six technical symposia each of which included basic research, applied technological design and development, and industrial and governmental integrated system and application demonstrations. The six symposia were: SYMP 1 Multifunctional Materials; SYMP 2 Active Materials, Mechanics and Behavior; SYMP 3 Modeling, Simulation and Control; SYMP 4 Enabling Technologies and Integrated System Design; SYMP 5 Structural Health Monitoring/NDE; and SYMP 6 Bio-inspired Smart Materials and Structures. In addition, the conference introduced a new student and young professional development symposium. Authors of papers in the materials areas (symposia 1, 2 and 6) were invited to write a full journal article on their presentation topic for publication in this special issue of Smart Materials and Structures. This set of papers demonstrates the exceptional quality and originality of the conference presentations. We are appreciative of their efforts in producing this collection of highly relevant articles on smart materials.

Historical Building Stability Monitoring by Means of a Cosmic Ray Tracking System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zenoni, Aldo; INFN Sezione di Pavia, Via Bassi 6, 27100 Pavia

Cosmic ray radiation is mostly composed, at sea level, by high energy muons, which are highly penetrating particles capable of crossing kilometers of rock. The ubiquitous and steady presence at the Earth's surface and the high penetration capability have motivated the use of cosmic ray radiation also in fields beyond particle physics, from geology, archaeology, speleology to industrial applications and homeland security. In particular, in recent years, the novel technique of muon tomography has been proposed, with the aim of performing non invasive inspection of large non accessible volumes, material atomic number Z and density discrimination, and three dimension imagemore » reconstruction of the inspected volume. In the present paper, after a short recall of the physical principles and mathematical formalism on which muon tomography is based, a number of examples of application of the novel technique in industry and homeland security issues is given. Moreover, a new application of cosmic rays detection techniques in the field of civil engineering is proposed. The aim is the monitoring of the stability of large structures, in particular the static monitoring of historical buildings, where conservation constraints are more severe and the time evolution of the deformation phenomena under study may be of the order of months or years. The new technique may be seen, in some way, as the reverse problem of muon tomography. As a significant case study, the monitoring of the wooden vaulted roof of the Palazzo della Loggia in the town of Brescia, in Italy, has been considered. The feasibility as well as the performances and limitations of a monitoring system based on cosmic ray tracking have been studied by Monte Carlo simulation and discussed in comparison with more traditional monitoring systems. (authors)« less

Evidence-Based Conclusions Concerning Practice, Curriculum Design and Curriculum Reform in a Civil Engineering Capstone Design Course in Hong Kong

ERIC Educational Resources Information Center

Chan, Cecilia K. Y.; Wong, George C. K.; Law, Ada K. H.; Zhang, T.; Au, Francis T. K.

2017-01-01

This study aimed to provide evidence-based conclusions from students concerning a capstone-design course in a civil engineering programme in Hong Kong. The evidence was generated by designing a student-experience questionnaire. The questionnaire instrument was assessed for internal consistency in four scales (curriculum and structure changes;…

Perceptions of Academic Staff towards Accommodating Students with Disabilities in a Civil Engineering Undergraduate Program in a University in South Africa

ERIC Educational Resources Information Center

Mayat, Nafisa; Amosun, Seyi Ladele

2011-01-01

This study explored the perceptions of academic staff towards admission of students with disabilities, and their accommodation once accepted into an undergraduate Civil Engineering program in a South African university. Qualitative responses relating to the perceptions of five academic staff were obtained through semi-structured interviews. The…

Pre-Service Teachers' Comments toward Official Teacher Selection System (Civil Servant Selection Examination, KPSS) in Turkey: A Qualitative Analysis

ERIC Educational Resources Information Center

Ugulu, Ilker; Yorek, Nurettin

2015-01-01

The purpose of this research is to investigate the opinions of the pre-service teachers toward teacher selection system and civil servant selection exam (KPSS). In this study, qualitative re-search methods and semi-structured interviews were used and researcher-made questionnaires containing open-ended questions were administered. The study group…

Learning about Environmental Issues in Engineering Programmes: A Case Study of First-Year Civil Engineering Students' Contextualisation of an Ecology Course

ERIC Educational Resources Information Center

Lundholm, Cecilia

2004-01-01

Describes how first-year civil engineering students interpreted the content and structure of an ecology course. Students' learning processes were analysed from an intentional perspective, i.e. a perspective that takes into account the students' educational aims and conceptions of the study situation. Interviews were carried out with six civil…

Shock-driven fluid-structure interaction for civil design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, Stephen L; Deiterding, Ralf

The multiphysics fluid-structure interaction simulation of shock-loaded structures requires the dynamic coupling of a shock-capturing flow solver to a solid mechanics solver for large deformations. The Virtual Test Facility combines a Cartesian embedded boundary approach with dynamic mesh adaptation in a generic software framework of flow solvers using hydrodynamic finite volume upwind schemes that are coupled to various explicit finite element solid dynamics solvers (Deiterding et al., 2006). This paper gives a brief overview of the computational approach and presents first simulations that utilize the general purpose solid dynamics code DYNA3D for complex 3D structures of interest in civil engineering.more » Results from simulations of a reinforced column, highway bridge, multistory building, and nuclear reactor building are presented.« less

[Drinking water: use, consume and biological hazard].

PubMed

Boccia, A; De Giusti, M; del Cimmuto, A

1995-01-01

The Authors drew the attention to the rising danger of water crisis also in countries usually immune from this problem. The most important causes of these crisis are presented along with some of the most important laws concerning civil use of water. The Authors underline the biological risk induced by new aetiologycal agents (i.e. aeromonas hydrophyla, Criptococcus, Escherichia coli (O:127 H7) found in drinking water too. Some of the health problems correlated to the civil use of water are also presented: water supply of hospitals, schools and hotels. The Authors conclude underlining that the answer to this problem must be found in a good management of water sources which requires efficient monitoring systems.

The Global Fund and the re-configuration and re-emergence of 'civil society': widening or closing the democratic deficit?

PubMed

Kapilashrami, Anuj; O'Brien, Oonagh

2012-01-01

The past decade has witnessed a tremendous growth in the scale and policy influence of civil society in global health governance. The AIDS 'industry' in particular opens up spaces for active mobilisation and participation of non-state actors, which further crystallise with an ever-increasing dominance of global health initiatives. While country evaluations of global initiatives call for a greater participation of 'civil society', the evidence base examining the organisation, nature and operation of 'civil society' and its claims to legitimacy is very thin. Drawing on the case of one of the most visible players in the global response to HIV epidemic, the Global Fund to Fight AIDS, Tuberculosis and Malaria, this article seeks to highlight the complex micropolitics of its interactions with civil society. It examines the nature of civil society actors involved in the Fund projects and the processes through which they gain credibility. We argue that the imposition of global structures and principles facilitates a reconfiguration of actors around newer forms of expertise and power centres. In this context, the notion of 'civil society' underplays differences and power dynamics between various institutions and conceals the agency of outsiders under the guise of autonomy of the state and people.

Adolescents' and young adults' conceptions of civil liberties: freedom of speech and religion.

PubMed

Helwig, C C

1995-02-01

This study examined adolescents' and young adults' conceptions of freedom of speech and religion (civil liberties). 48 adolescents and young adults in 3 grade levels (mean ages 12-8, 16-10, and 19-6) were administered a structured interview containing assessments of civil liberties in general, in straightforward (unconflicted) applications, and in conflict with other social and moral concerns, including law, physical and psychological harm, and equality of opportunity. Freedom of speech and religion were conceptualized as universal rights and applied to social events in unconflicted contexts at all ages. A diverse array of rationales, differentiated according to type of freedom, were used at all ages to ground conceptions of universal freedoms. Judgments of civil liberties in conflicts exhibited several sources of variation, including developmental differences, situational or contextual variation determined by the particular types of issues in conflict, and individual differences. Results are consistent with the proposition that judgments of civil liberties reflect age-related patterns of coordination of delimited social and moral concepts rather than general orientations.

Emergency management of the 2010 Mt. Rotolon landslide by means of a local scale GB-InSAR monitoring system

NASA Astrophysics Data System (ADS)

Frodella, William; Pazzi, Veronica; Morelli, Stefano; Salvatici, Teresa; Fanti, Riccardo

2017-04-01

Between October 31st and November 2nd 2010 the whole Veneto region (north-eastern Italy) was hit by heavy and persistent rainfall, which diffusely triggered floods and slope failures. In this framework on November 4th 2010 a detrital mass, approximately 225.000 m3 in volume, detached from the lowermost sector of the Mt. Rotolon landslide cover (located in the Vicentine Pre-Alps, upper Agno River Valley), channelizing within the Rotolon Creek riverbed and evolving into a highly mobile debris flow. The latter phenomena, characterized by a 3 km travel distance, damaged many hydraulic works, putting at high risk bridges and local roads located along the creek banks, together with the population of both the town of Recoaro Terme and the villages of Maltaure, Turcati and Parlati. Starting from the beginning of the emergency phase, the Civil Protection system was activated, involving the National Civil Protection Department, Veneto Region and local administrations personnel and technicians, as well as research centers. On December 8th 2010 a local scale monitoring system, based on a ground based interferometric radar (GB-InSAR), was implemented in order to evaluate the slope deformation pattern evolution in correspondence of the debris flow detachment sector, with the final aim of assessing the landslide residual risk and manage the emergency phase. Accurate geomorphological field surveys were also carried out, in order to study the landslide morphological features as to improve the radar data interpretation. The radar system acquired in continuous GB-InSAR data, such as displacement maps and time series of 10 selected monitoring points, which were uploaded via LAN network on a dedicated Web-based interface, shared with the technical stakeholders and decision makers involved in the emergency management and allowing for a near real time data routine visualization. This paper describes the outcomes of a 2 years GB-InSAR monitoring campaign (December 2010-November 2012), reporting the various applications of GB-InSAR data for monitoring, mapping and emergency management activities, in order to provide a rapid and easy communication of the results to the involved technicians and civil protection personnel, for a better understanding of the landslide phenomena and decision making process in a critical landslide scenario.

Sustainable development goals for global health: facilitating good governance in a complex environment.

PubMed

Haffeld, Just

2013-11-01

Increasing complexity is following in the wake of rampant globalization. Thus, the discussion about Sustainable Development Goals (SDGs) requires new thinking that departs from a critique of current policy tools in exploration of a complexity-friendly approach. This article argues that potential SDGs should: treat stakeholders, like states, business and civil society actors, as agents on different aggregate levels of networks; incorporate good governance processes that facilitate early involvement of relevant resources, as well as equitable participation, consultative processes, and regular policy and programme implementation reviews; anchor adoption and enforcement of such rules to democratic processes in accountable organizations; and include comprehensive systems evaluations, including procedural indicators. A global framework convention for health could be a suitable instrument for handling some of the challenges related to the governance of a complex environment. It could structure and legitimize government involvement, engage stakeholders, arrange deliberation and decision-making processes with due participation and regular policy review, and define minimum standards for health services. A monitoring scheme could ensure that agents in networks comply according to whole-systems targets, locally defined outcome indicators, and process indicators, thus resolving the paradox of government control vs. local policy space. A convention could thus exploit the energy created in the encounter between civil society, international organizations and national authorities. Copyright © 2013 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

Civil society engagement in multi-stakeholder dialogue: a qualitative study exploring the opinions and perceptions of MeTA members.

PubMed

Buckland-Merrett, Gemma L; Kilkenny, Catherine; Reed, Tim

2017-01-01

The Medicines Transparency Alliance (MeTA) is an initiative that brings together all stakeholders in the medicines market to create a multi-stakeholder dialogue and improve access, availability and affordability of medicines. Key to this multi-stakeholder dialogue is the participation of Civil Society Organisations. A recent MeTA annual review, identified uneven engagement of civil society organisations in the multi-stakeholder process. This study was designed to explore the engagement of Civil Society Organisations in the MeTA multi-stakeholder process and the factors influencing their participation. Participants were drawn from a convenience sample of key MeTA informants attending a MeTA global meeting in Geneva in 2014. Study participants consisted of members of MeTA, which included representatives from government, the private sector and civil society. In-depth semi-structured face-to-face interviews were conducted to identify perceptions around the barriers to civil society engagement in the multi-stakeholder process. Interviews were guided by a conceptual framework exploring the three main themes of the political environment, relative stakeholder strength and agenda setting/gatekeepers. Interviews were structured to enable additional themes to emerge and be explored. Fifteen interviews were conducted. The interviews were audio recorded, transcribed verbatim and analysed using a general inductive approach. All interviewees provided written informed consent. Findings were captured within three main overarching themes: the political environment, relative stakeholder strength and agenda setting/gatekeepers, with the opportunity for additional themes to emerge in the interviewing process. The study conformed these three themes were important in the engagement process. Participants reported that civil society engagement is particularly limited by those who set the agenda. It was largely seen that the political environment was the significant factor that enabled or disabled all others. The findings counter the argument that CSO barriers to engagement are predominantly due to capacity issues. This study enriches previous findings by providing insights into civil society participation in multi-stakeholder dialogue, specifically the MeTA initiative. The development of more rigorous and systematic accountability mechanisms in order to maintain the legitimacy of decision-making processes and establish more equal power relations would significantly benefit the engagement of civil society organisations. The results inform practical recommendations for MeTA and future multi-stakeholder programmes tasked with improving policy on the access, availability and affordability of medicines.

Concepts and Development of Bio-Inspired Distributed Embedded Wired/Wireless Sensor Array Architectures for Acoustic Wave Sensing in Integrated Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Ghoshal, Anindya; Prosser, William H.; Kirikera, Goutham; Schulz, Mark J.; Hughes, Derke J.; Orisamolu, Wally

2003-01-01

This paper discusses the modeling of acoustic emissions in plate structures and their sensing by embedded or surface bonded piezoelectric sensor arrays. Three different modeling efforts for acoustic emission (AE) wave generation and propagation are discussed briefly along with their advantages and disadvantages. Continuous sensors placed at right angles on a plate are being discussed as a new approach to measure and locate the source of acoustic waves. Evolutionary novel signal processing algorithms and bio-inspired distributed sensor array systems are used on large structures and integrated aerospace vehicles for AE source localization and preliminary results are presented. These systems allow for a great reduction in the amount of data that needs to be processed and also reduce the chances of false alarms from ambient noises. It is envisioned that these biomimetic sensor arrays and signal processing techniques will be useful for both wireless and wired sensor arrays for real time health monitoring of large integrated aerospace vehicles and earth fixed civil structures. The sensor array architectures can also be used with other types of sensors and for other applications.

Nonlinear damage detection in composite structures using bispectral analysis

NASA Astrophysics Data System (ADS)

Ciampa, Francesco; Pickering, Simon; Scarselli, Gennaro; Meo, Michele

2014-03-01

Literature offers a quantitative number of diagnostic methods that can continuously provide detailed information of the material defects and damages in aerospace and civil engineering applications. Indeed, low velocity impact damages can considerably degrade the integrity of structural components and, if not detected, they can result in catastrophic failure conditions. This paper presents a nonlinear Structural Health Monitoring (SHM) method, based on ultrasonic guided waves (GW), for the detection of the nonlinear signature in a damaged composite structure. The proposed technique, based on a bispectral analysis of ultrasonic input waveforms, allows for the evaluation of the nonlinear response due to the presence of cracks and delaminations. Indeed, such a methodology was used to characterize the nonlinear behaviour of the structure, by exploiting the frequency mixing of the original waveform acquired from a sparse array of sensors. The robustness of bispectral analysis was experimentally demonstrated on a damaged carbon fibre reinforce plastic (CFRP) composite panel, and the nonlinear source was retrieved with a high level of accuracy. Unlike other linear and nonlinear ultrasonic methods for damage detection, this methodology does not require any baseline with the undamaged structure for the evaluation of the nonlinear source, nor a priori knowledge of the mechanical properties of the specimen. Moreover, bispectral analysis can be considered as a nonlinear elastic wave spectroscopy (NEWS) technique for materials showing either classical or non-classical nonlinear behaviour.

Qualitative and quantitative changes in phospholipids and proteins investigated by spectroscopic techniques in olfactory bulbectomy animal depression model.

PubMed

Depciuch, J; Parlinska-Wojtan, M

2018-01-30

Depression becomes nowadays a high mortality civilization disease with one of the potential causes being impaired smell. In this study Raman, Fourier Transform Infra Red (FTIR) and Ultraviolet-Visible (UV-vis) spectroscopies were used to determine the changes in the quantity and structure of phospholipids and proteins in the blood serum of bulbectomized rats (OB_NaCl), which is a common animal depression model. The efficiency of amitriptyline (AMI) treatment was also evaluated. The obtained results show a significant decrease in the phospholipid and protein fractions (as well as changes in their secondary structures) in blood serum of bulbectomized rats. AMI treatment in bulbectomized rats increased protein level and did not affect the level of phospholipids. Structural information from phospholipids and proteins was obtained from UV-vis spectroscopy combined with the second derivative of the FTIR spectra. Indeed, the structure of proteins in blood serum of bulbectomized rats was normalized after amitriptyline therapy, while the damaged structure of phospholipids remained unaffected. These findings strongly suggest that impaired smell could be one of the causes of depression and may induce permanent (irreversible) damages into the phospholipid structure identified as shortened carbon chains. This study shows a possible new application of spectroscopic techniques in the diagnosis and therapy monitoring of depression. Copyright © 2017 Elsevier B.V. All rights reserved.

5 CFR 880.102 - Regulatory structure.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Regulatory structure. 880.102 Section 880.102 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS... Regulatory structure. (a) This part contains the following subparts: (1) Subpart A contains general...

A Monumental Lesson: What Historical Structures Can Tell Us

ERIC Educational Resources Information Center

Craven, Jacqueline S.; Sumrall, William J.; Moore, Jerilou J.; Logan, Kellie

2011-01-01

Historical structures have connected civilization across time as a representation of important events, famous people, or experiences of diverse cultures. The value systems of a society are reflected in these structures and convey political and historical information. Knowledge about historical structures provides understanding of cultures of…

A study of facilities and fixtures for testing of a high speed civil transport wing component

NASA Technical Reports Server (NTRS)

Cerro, J. A.; Vause, R. F.; Bowman, L. M.; Jensen, J. K.; Martin, C. J., Jr.; Stockwell, A. E.; Waters, W. A., Jr.

1996-01-01

A study was performed to determine the feasibility of testing a large-scale High Speed Civil Transport wing component in the Structures and Materials Testing Laboratory in Building 1148 at NASA Langley Research Center. The report includes a survey of the electrical and hydraulic resources and identifies the backing structure and floor hard points which would be available for reacting the test loads. The backing structure analysis uses a new finite element model of the floor and backstop support system in the Structures Laboratory. Information on the data acquisition system and the thermal power requirements is also presented. The study identified the hardware that would be required to test a typical component, including the number and arrangement of hydraulic actuators required to simulate expected flight loads. Load introduction and reaction structure concepts were analyzed to investigate the effects of experimentally induced boundary conditions.

Human Factors Evaluation of the Hidalgo Equivital EQ-02 Physiological Status Monitoring System

DTIC Science & Technology

2013-10-11

Destruction – Civil Support Team (WMD-CST) responding (11), and ricin letters that were intercepted en route to a member of Congress and the President...positive for ricin at Washington mail facility. CNN U.S., April 17, 2013. (http://www.cnn.com/2013/04/16/us/tainted-letter- intercepted accessed

The Position of a Teacher as a Factor of Forming Students' Socio-Cultural Identities (On the Example of the Russian Civil Identity)

ERIC Educational Resources Information Center

Shakurova, Marina V.

2015-01-01

The article presents experience of structuring and description of teachers' position in the process of forming socio-cultural identity of the person, detailed in regard to the process of formation of one of the subtypes of socio-cultural identity--Russian civil identity. We identified and described real subjective, nominally subjective and…

Instructional Complements for Undergraduate World History or Western Civilization Courses: Selected Topics in the Ancient, Medieval, and Modern History of India: A Curriculum Supplement.

ERIC Educational Resources Information Center

Wiley, Wayne Hamilton

This curriculum supplement on India consists of three modules that have been used with undergraduates in introductory world civilization courses. Module 1, "Ancient Period: Hinduism and the Caste System in India: Origin, Development, and Social Functions" discusses the religious doctrines of Hinduism, the caste system, and its structure.…

Hyperresolution: an hyperspectral and high resolution imager for Earth observation

NASA Astrophysics Data System (ADS)

De Vidi, R.; Chiarantini, L.; Bini, A.

2017-11-01

Hyperspectral space imagery is an emerging technology that supports many scientific, civil, security and defence operational applications. The main advantage of this remote sensing technique is that it allows the so-called Feature Extraction: in fact the spectral signature allows the recognition of the materials composing the scene. Hyperspectral Products and their applications have been investigated in the past years by Galileo Avionica to direct the instrument characteristics design. Sample products have been identified in the civil / environment monitoring fields (such as coastal monitoring, vegetation, hot spot and urban classification) and in defense / security applications: their performances have been verified by means of airborne flight campaigns. The Hyperspectral and High Resolution Imager is a space-borne instrument that implement a pushbroom technique to get strip spectral images over the Hyperspectral VNIR and SWIR bands, with a ground sample distance at nadir of 20m in a 20 km wide ground swath, with 200 spectral channels, realizing an average spectral resolution of 10nm. The High Resolution Panchromatic Channel insists in the same swath to allow for multiresolution data fusion of hyperspectral imagery.

Mechanically induced long period fiber gratings in Er3+ fiber for structural health monitoring

NASA Astrophysics Data System (ADS)

Pulido-Navarro, M. G.; Alvarez-Chavez, J. A.; Ceballos-Herrera, D. E.; Escamilla-Ambrosio, P. J.

2013-09-01

This work presents preliminary results on wavelength sensitivity due to mechanically induced long period fiber grating (LPFG) on both standard single-mode and Er-doped fibers. The work presents and compares results for both types of fibers under different torsion conditions. In order to apply the torsion one of the fiber ends is fixed while torsion is applied on the other end. A LPFG whose period is 503μm is used to press on the fiber after the torsion, this will allow for micro curvatures to be formed on the fiber, which will in turn generate a periodical index perturbation on it. Here, it was noted that the rejection band shifts to shorter wavelengths for Er-doped fibers. It was detected that for torsion of 6 turns applied to 10cm doped fiber the wavelength peaks can shift up to 25nm, which is longer than similar results reported on standard fibers. Therefore, by using Er-doped fibers this technique will give more sensitive and accurate results on the real conditions of the structure under study. These results can be employed for sensing applications, especially for small to medium size structures, being these structures mechanical, civil or aeronautical. Theoretical calculations and simulations are employed for experimental results validation.

Israel’s Interests and Options in Syria

DTIC Science & Technology

2016-01-01

israel-syria-druze-golan-heights-assad-rebels-civil-war.html ———, “Israel Fears Return of Persian Empire,” Al-Monitor, September 21, 2015b. As of...December 14, 2015: http://www.al-monitor.com/pulse/originals/2015/09/ israel-fear- persian -empire-iran-shiite-hezbollah-axis-nuke.html ———, “Russia, Israeli...December 14, 2015: http://www.israeltoday.co.il/NewsItem/tabid/178/nid/23796/Default.aspx Peled, Daniella, “ISIS in Jordan: King Abdullah’s Battle for the

Development of a PVDF film sensor for infrastructure monitoring

NASA Astrophysics Data System (ADS)

Satpathi, Debashis; Victor, J. P.; Wang, Ming L.; Yang, H. Y.; Shih, C. C.

1999-05-01

Development of a health monitoring system is of vital importance for all civil infrastructures. However, this effort has been stymied in part by the lack of suitable low priced sensors and associated signal conditioning. Very often the requirement of a controlled stable power supply to the sensor itself poses another challenge. Piezoelectric polymer films offer an excellent alternative to the ubiquitous strain gage technology. The PVDF film generates an electrical charge when mechanically deformed. The PVDF film is typically a high impedance source with a capacitance in the nanofarad range and measurement of low frequency event can pose a challenge. The authors have utilized a charge mode amplification scheme for measuring quasi-static processes. The processed signal can be transmitted to a data acquisition system via a RF microelectronic circuit. The PVDF film as a transducer can be cut to very small size and are very affordable at around 50 cents per sensor. The whole circuitry can be integrated into one single unit. It would require very low power to function and could be embedded in the structure for a large number of remote applications. In this article the authors have reported the result of the various characterization test that have been carried out to determine the suitability of the basic film as the core of an autoadaptive sensor system to be designed for infrastructure monitoring.

Analysis of building deformation in landslide area using multisensor PSInSAR™ technique.

PubMed

Ciampalini, Andrea; Bardi, Federica; Bianchini, Silvia; Frodella, William; Del Ventisette, Chiara; Moretti, Sandro; Casagli, Nicola

2014-12-01

Buildings are sensitive to movements caused by ground deformation. The mapping both of spatial and temporal distribution, and of the degree of building damages represents a useful tool in order to understand the landslide evolution, magnitude and stress distribution. The high spatial resolution of space-borne SAR interferometry can be used to monitor displacements related to building deformations. In particular, PSInSAR technique is used to map and monitor ground deformation with millimeter accuracy. The usefulness of the above mentioned methods was evaluated in San Fratello municipality (Sicily, Italy), which was historically affected by landslides: the most recent one occurred on 14th February 2010. PSInSAR data collected by ERS 1/2, ENVISAT, RADARSAT-1 were used to study the building deformation velocities before the 2010 landslide. The X-band sensors COSMO-SkyMed and TerraSAR-X were used in order to monitor the building deformation after this event. During 2013, after accurate field inspection on buildings and structures, damage assessment map of San Fratello were created and then compared to the building deformation velocity maps. The most interesting results were obtained by the comparison between the building deformation velocity map obtained through COSMO-SkyMed and the damage assessment map. This approach can be profitably used by local and Civil Protection Authorities to manage the post-event phase and evaluate the residual risks.

An Embedded Stress Sensor for Concrete SHM Based on Amorphous Ferromagnetic Microwires

PubMed Central

Olivera, Jesús; González, Margarita; Fuente, José Vicente; Varga, Rastislav; Zhukov, Arkady; Anaya, José Javier

2014-01-01

A new smart concrete aggregate design as a candidate for applications in structural health monitoring (SHM) of critical elements in civil infrastructure is proposed. The cement-based stress/strain sensor was developed by utilizing the stress/strain sensing properties of a magnetic microwire embedded in cement-based composite (MMCC). This is a contact-less type sensor that measures variations of magnetic properties resulting from stress variations. Sensors made of these materials can be designed to satisfy the specific demand for an economic way to monitor concrete infrastructure health. For this purpose, we embedded a thin magnetic microwire in the core of a cement-based cylinder, which was inserted into the concrete specimen under study as an extra aggregate. The experimental results show that the embedded MMCC sensor is capable of measuring internal compressive stress around the range of 1–30 MPa. Two stress sensing properties of the embedded sensor under uniaxial compression were studied: the peak amplitude and peak position of magnetic switching field. The sensitivity values for the amplitude and position within the measured range were 5 mV/MPa and 2.5 μs/MPa, respectively. PMID:25347582

Analysis, compensation, and correction of temperature effects on FBG strain sensors

NASA Astrophysics Data System (ADS)

Haber, T. C.; Ferguson, S.; Guthrie, D.; Graver, T. W.; Soller, B. J.; Mendez, Alexis

2013-05-01

One of the most common fiber optic sensor (FOS) types used are fiber Bragg gratings (FBG), and the most frequently measured parameter is strain. Hence, FBG strain sensors are one of the most prevalent FOS devices in use today in structural sensing and monitoring in civil engineering, aerospace, marine, oil and gas, composites and smart structure applications. However, since FBGs are simultaneously sensitive to both temperature and strain, it becomes essential to utilize sensors that are either fully temperature insensitive or, alternatively, properly temperature compensated to avoid erroneous measurements. In this paper, we introduce the concept of measured "total strain", which is inherent and unique to optical strain sensors. We review and analyze the temperature and strain sensitivities of FBG strain sensors and decompose the total measured strain into thermal and non-thermal components. We explore the differences between substrate CTE and System Thermal Response Coefficients, which govern the type and quality of thermal strain decomposition analysis. Finally, we present specific guidelines to achieve proper temperature-insensitive strain measurements by combining adequate installation, sensor packaging and data correction techniques.

Design of structures against fire. Civil engineering/buildings, architecture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anchor, R.D.; Malhotra, H.L.; Purkiss, J.A.

1986-01-01

The book covers structural design criteria, along with background theory on fire protection methods for structures from a variety of materials, including timber, steel, and concrete. Research on the behavior of structural materials in the presence of fire is highlighted, and the need for fire-resistant materials is addressed.

5 CFR 847.102 - Regulatory structure.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Regulatory structure. 847.102 Section 847.102 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS... INSTRUMENTALITIES General Provisions § 847.102 Regulatory structure. (a)(1) Subpart A of this part contains...

Distributed Humidity Sensing in PMMA Optical Fibers at 500 nm and 650 nm Wavelengths.

PubMed

Liehr, Sascha; Breithaupt, Mathias; Krebber, Katerina

2017-03-31

Distributed measurement of humidity is a sought-after capability for various fields of application, especially in the civil engineering and structural health monitoring sectors. This article presents a method for distributed humidity sensing along polymethyl methacrylate (PMMA) polymer optical fibers (POFs) by analyzing wavelength-dependent Rayleigh backscattering and attenuation characteristics at 500 nm and 650 nm wavelengths. Spatially resolved humidity sensing is obtained from backscatter traces of a dual-wavelength optical time domain reflectometer (OTDR). Backscatter dependence, attenuation dependence as well as the fiber length change are characterized as functions of relative humidity. Cross-sensitivity effects are discussed and quantified. The evaluation of the humidity-dependent backscatter effects at the two wavelength measurements allows for distributed and unambiguous measurement of relative humidity. The technique can be readily employed with low-cost standard polymer optical fibers and commercial OTDR devices.

The Use of 3d City Models Form Oblique Images on Land Administration

NASA Astrophysics Data System (ADS)

Bakici, S.; Erkek, B.; Ayyildiz, E.; Özmüş, L.

2017-11-01

The article 718 of the civil law saying "The ownership on property includes the air above and terrain layers below to an extent providing benefit. The structures, plants and sources are included in the content of this ownership reserving the legal restrictions" and the cadastre law no. 3402 envisage 3D Cadastre. 3D data is required in order to perform 3D cadastre. To meet this requirement, oblique photogrammetry arises as the main data acquisition method. The data obtained by this method is used as base in 3D Cadastre and Land Administration activities. 3D cadastre required in the context of land administration activities in Turkey demands high resolution aerial oblique images to be used in services such as real estate value assessment & marketing in urban areas, urban planning, unlicensed construction monitoring & city administration and making location data (national address data etc.) intelligent.

Harvesting Social Signals to Inform Peace Processes Implementation and Monitoring

PubMed Central

Nigam, Aastha; Dambanemuya, Henry K.; Joshi, Madhav; Chawla, Nitesh V.

2017-01-01

Abstract Peace processes are complex, protracted, and contentious involving significant bargaining and compromising among various societal and political stakeholders. In civil war terminations, it is pertinent to measure the pulse of the nation to ensure that the peace process is responsive to citizens' concerns. Social media yields tremendous power as a tool for dialogue, debate, organization, and mobilization, thereby adding more complexity to the peace process. Using Colombia's final peace agreement and national referendum as a case study, we investigate the influence of two important indicators: intergroup polarization and public sentiment toward the peace process. We present a detailed linguistic analysis to detect intergroup polarization and a predictive model that leverages Tweet structure, content, and user-based features to predict public sentiment toward the Colombian peace process. We demonstrate that had proaccord stakeholders leveraged public opinion from social media, the outcome of the Colombian referendum could have been different. PMID:29235916

Fatigue crack localization with near-field acoustic emission signals

NASA Astrophysics Data System (ADS)

Zhou, Changjiang; Zhang, Yunfeng

2013-04-01

This paper presents an AE source localization technique using near-field acoustic emission (AE) signals induced by crack growth and propagation. The proposed AE source localization technique is based on the phase difference in the AE signals measured by two identical AE sensing elements spaced apart at a pre-specified distance. This phase difference results in canceling-out of certain frequency contents of signals, which can be related to AE source direction. Experimental data from simulated AE source such as pencil breaks was used along with analytical results from moment tensor analysis. It is observed that the theoretical predictions, numerical simulations and the experimental test results are in good agreement. Real data from field monitoring of an existing fatigue crack on a bridge was also used to test this system. Results show that the proposed method is fairly effective in determining the AE source direction in thick plates commonly encountered in civil engineering structures.

Harvesting Social Signals to Inform Peace Processes Implementation and Monitoring.

PubMed

Nigam, Aastha; Dambanemuya, Henry K; Joshi, Madhav; Chawla, Nitesh V

2017-12-01

Peace processes are complex, protracted, and contentious involving significant bargaining and compromising among various societal and political stakeholders. In civil war terminations, it is pertinent to measure the pulse of the nation to ensure that the peace process is responsive to citizens' concerns. Social media yields tremendous power as a tool for dialogue, debate, organization, and mobilization, thereby adding more complexity to the peace process. Using Colombia's final peace agreement and national referendum as a case study, we investigate the influence of two important indicators: intergroup polarization and public sentiment toward the peace process. We present a detailed linguistic analysis to detect intergroup polarization and a predictive model that leverages Tweet structure, content, and user-based features to predict public sentiment toward the Colombian peace process. We demonstrate that had proaccord stakeholders leveraged public opinion from social media, the outcome of the Colombian referendum could have been different.

Use of Sentinel-1 SAR data to monitor Mosul dam vulnerability

NASA Astrophysics Data System (ADS)

Riccardi, Paolo; Tessari, Giulia; Lecci, Daniele; Floris, Mario; Pasquali, Paolo

2017-04-01

The structural monitoring of dams is an important practice to guarantee their safety. Moreover, the water reservoir and the efficient operation and safety of surrounding areas need to be monitored. Considering the importance of large dams as multipurpose infrastructure for flood control, energy production, water supply and irrigation, ensuring their longevity is a key aspect on their management. Therefore, it is of great importance to detect dam deterioration potentially resulting in its shutdown or failure, preventing life and economic losses. Traditional dam monitoring requires the identification of soil movements, tilt, displacements, structural stress and strain behaviour. Since the '90, innovative remote sensing techniques based on satellite Synthetic Aperture Radar (SAR) data were developed to detect and monitor surface displacements. The main advantages of SAR data are the non-invasiveness of their acquisition, the possibility to cover large areas in a short time and the advancement. Moreover, the availability of SAR satellite acquisitions from the 1990s enables to reconstruct the historical evolution of dam behaviour. Furthermore, the use of SAR Interferometry (InSAR) techniques, Differential InSAR (DInSAR) and Advanced stacking techniques (A-DInSAR), produce accurate velocity maps and displacement time-series. The importance of these techniques emerges when environmental or logistic conditions do not allow to monitor dams applying the traditional geodetic techniques. An iconic case demonstrating the relevance of remote sensing observations is the Mosul Dam, the largest Iraqi dam, where monitoring and maintaining are impeded for political controversy, thus the risk for the population is very high. It is considered one of the most dangerous dams in the world because of the erosion of the gypsum rock at the basement and the difficult interventions due to security issues. It consists of 113 m tall and 3.4 km long earth-fill embankment-type, with a clay core. It was completed in 1984 and started generating power on 1986. Since then, frequent consolidation works have been carried out pumping cement mixtures into the soil foundation to keep it stable and prevent it from sinking and then breaking apart. To overcome the impossibility of directly monitoring the structure, analysis of recent deformation affecting the Mosul dam is achieved considering C-band Sentinel-1 SAR data, acquired from the end of 2014 to the present. These 20-m ground resolution data can provide a millimetric precision on displacements. Furthermore, ESA archive available SAR data (ERS and Envisat) are considered to reconstruct the temporal evolution of the deformations. In this work, different stacks of data are processed applying SBAS and PS A-DInSAR techniques; deformation fields obtained from SAR data are evaluated to assess the temporal evolution of the strains affecting the structure. Obtained results represent the preliminary stage of a multidisciplinary project, finalised to assess possible damages affecting a dam through remote sensing and civil engineering surveys.

Compact Embedded Wireless Sensor-Based Monitoring of Concrete Curing.

PubMed

Cabezas, Joaquín; Sánchez-Rodríguez, Trinidad; Gómez-Galán, Juan Antonio; Cifuentes, Héctor; González Carvajal, Ramón

2018-03-15

This work presents the design, construction and testing of a new embedded sensor system for monitoring concrete curing. A specific mote has been implemented to withstand the aggressive environment without affecting the measured variables. The system also includes a real-time monitoring application operating from a remote computer placed in a central location. The testing was done in two phases: the first in the laboratory, to validate the functional requirements of the developed devices; and the second on civil works to evaluate the functional features of the devices, such as range, robustness and flexibility. The devices were successfully implemented resulting in a low cost, highly reliable, compact and non-destructive solution.

Compact Embedded Wireless Sensor-Based Monitoring of Concrete Curing

PubMed Central

Cabezas, Joaquín; Sánchez-Rodríguez, Trinidad; González Carvajal, Ramón

2018-01-01

This work presents the design, construction and testing of a new embedded sensor system for monitoring concrete curing. A specific mote has been implemented to withstand the aggressive environment without affecting the measured variables. The system also includes a real-time monitoring application operating from a remote computer placed in a central location. The testing was done in two phases: the first in the laboratory, to validate the functional requirements of the developed devices; and the second on civil works to evaluate the functional features of the devices, such as range, robustness and flexibility. The devices were successfully implemented resulting in a low cost, highly reliable, compact and non-destructive solution. PMID:29543765

A review of fiber-optic corrosion sensor in civil engineering

NASA Astrophysics Data System (ADS)

Luo, Dong; Li, Junnan; Li, Yuanyuan

2018-05-01

Fiber-optical corrosion sensor (FOCS) is the research hotspot of corrosion monitoring sensor in recent years. It has the advantages of lightness, simplicity, anti-electromagnetic interference and distributed measurement, so it has an attractive application prospect. In this paper, the mechanism of metal corrosion is introduced. Several common methods for detecting optical fiber corrosion sensors are presented, and the latest progress of optical fiber corrosion sensors in recent years is described. We need to design a set of sensor devices that can directly monitor the corrosion of reinforcing steel bars directly, and propose a method of time dependent reliability assessment based on monitoring data, so as to form a complete research path.

Civil propulsion technology for the next twenty-five years

NASA Technical Reports Server (NTRS)

Rosen, Robert; Facey, John R.

1987-01-01

The next twenty-five years will see major advances in civil propulsion technology that will result in completely new aircraft systems for domestic, international, commuter and high-speed transports. These aircraft will include advanced aerodynamic, structural, and avionic technologies resulting in major new system capabilities and economic improvements. Propulsion technologies will include high-speed turboprops in the near term, very high bypass ratio turbofans, high efficiency small engines and advanced cycles utilizing high temperature materials for high-speed propulsion. Key fundamental enabling technologies include increased temperature capability and advanced design methods. Increased temperature capability will be based on improved composite materials such as metal matrix, intermetallics, ceramics, and carbon/carbon as well as advanced heat transfer techniques. Advanced design methods will make use of advances in internal computational fluid mechanics, reacting flow computation, computational structural mechanics and computational chemistry. The combination of advanced enabling technologies, new propulsion concepts and advanced control approaches will provide major improvements in civil aircraft.

Trial guidelines for the conservation of Virginia's historic bridges.

DOT National Transportation Integrated Search

1986-01-01

Interest in the preservation of historic engineering structures has increased dramatically over the past decade. Because civil engineering structures primarily serve functions in the public domain, their preservation focuses attention on what appear ...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zenoni, Aldo; INFN Sezione di Pavia, Via Bassi 6, 27100 Pavia,

Cosmic ray radiation is mostly composed, at sea level, by high energy muons, which are highly penetrating particles capable of crossing kilometers of rock. The ubiquitous and steady presence at the Earth's surface and the high penetration capability have motivated the use of cosmic ray radiation also in fields beyond particle physics, from geology, archaeology, speleology to industrial applications and homeland security. In particular, in recent years, the novel technique of muon tomography has been proposed, with the aim of performing non invasive inspection of large non accessible volumes, material atomic number Z and density discrimination, and three dimension imagemore » reconstruction of the inspected volume. In the present paper, after a short recall of the physical principles and mathematical formalism on which muon tomography is based, a number of examples of application of the novel technique in industry and homeland security issues is given. Moreover, a new application of cosmic rays detection techniques in the field of civil engineering is proposed. The aim is the monitoring of the stability of large structures, in particular the static monitoring of historical buildings, where conservation constraints are more severe and the time evolution of the deformation phenomena under study may be of the order of months or years. The new technique may be seen, in some way, as the reverse problem of muon tomography. As a significant case study, the monitoring of the wooden vaulted roof of the Palazzo della Loggia in the town of Brescia, in Italy, has been considered. The feasibility as well as the performances and limitations of a monitoring system based on cosmic ray tracking have been studied by Monte Carlo simulation and discussed in comparison with more traditional monitoring systems. (authors)« less

Life Modeling for Nickel-Hydrogen Batteries in Geosynchronous Satellite Operation

DTIC Science & Technology

2005-03-25

aerothermodynamics; chemical and electric propulsion; environmental chemistry; combustion processes; space environment effects on materials, hardening and...intelligent microinstruments for monitoring space and launch system environments . Space Science Applications Laboratory: Magnetospheric, auroral and cosmic-ray...hyperspectral imagery to defense, civil space, commercial, and environmental missions; effects of solar activity, magnetic storms and nuclear explosions on the

Results for Learning Report 2012: Fostering Evidence-Based Dialogue to Monitor Access and Quality in Education

ERIC Educational Resources Information Center

Cortese, Lauren; Crouch, Luis; Pinto, Nancy; Salgado, Vania; Schmidt, Caroline; Soman, Kouassi; Thiam, Mamadou; Chaluda, Ania; Omoeva, Carina

2012-01-01

The Global Partnership for Education (GPE) works with low-income countries around the world to help them provide basic education of good quality to all of their children. Countries develop education sector plans that set clear targets and commitments; their partners including donors, multilateral agencies, civil society and the private sector…

Fiber Bragg gratings for civil engineering applications

NASA Astrophysics Data System (ADS)

Maher, Mohamed H.; Tabrizi, Khosrow; Prohaska, John D.; Snitzer, Elias

1996-04-01

Fiber Bragg gratings sensors offer a unique opportunity in civil engineering. They can be configured as a low noise distributed sensor network for measuring mechanical deformations and temperature. They are ideally suited for strain measurements of high modulus structural materials such as steel and concrete. There is considerable interest in the use of these sensors for infrastructural nondestructive testing and there have been several papers on the subject. We present some results of our experiments with fiber Bragg sensors as applied to structural engineering. These include the use of fiber gratings to measure strain behavior of steel, reinforced concrete, and some preliminary results on bituminous materials, such as asphalt concrete. In nondestructive testing using fiber Bragg gratings of structural materials the packaging of the sensors is important and is discussed.

Improving the durability of the optical fiber sensor based on strain transfer analysis

NASA Astrophysics Data System (ADS)

Wang, Huaping; Jiang, Lizhong; Xiang, Ping

2018-05-01

To realize the reliable and long-term strain detection, the durability of optical fiber sensors has attracted more and more attention. The packaging technique has been considered as an effective method, which can enhance the survival ratios of optical fiber sensors to resist the harsh construction and service environment in civil engineering. To monitor the internal strain of structures, the embedded installation is adopted. Due to the different material properties between host material and the protective layer, the monitored structure embedded with sensors can be regarded as a typical model containing inclusions. Interfacial characteristic between the sensor and host material exists obviously, and the contacted interface is prone to debonding failure induced by the large interfacial shear stress. To recognize the local interfacial debonding damage and extend the effective life cycle of the embedded sensor, strain transfer analysis of a general three-layered sensing model is conducted to investigate the failure mechanism. The perturbation of the embedded sensor on the local strain field of host material is discussed. Based on the theoretical analysis, the distribution of the interfacial shear stress along the sensing length is characterized and adopted for the diagnosis of local interfacial debonding, and the sensitive parameters influencing the interfacial shear stress are also investigated. The research in this paper explores the interfacial debonding failure mechanism of embedded sensors based on the strain transfer analysis and provides theoretical basis for enhancing the interfacial bonding properties and improving the durability of embedded optical fiber sensors.

Education and Telecommunications

ERIC Educational Resources Information Center

Frankel, Charles

1970-01-01

Reform of social and educational structures is essential to realize the full educational potential of telecommunications, which can be used to help that reform, to cement prsent inadequate structures in place, or to build a human civilization on a technological base. (AD)