Quality control and in-service inspection technology for hybrid-composite girder bridges.

DOT National Transportation Integrated Search

2014-08-01

This report describes efforts to develop quality control tools and in-service inspection technologies for the fabrication and construction of Hybrid Composite Beams (HCBs). HCBs are a new bridge technology currently being evaluated by the Missouri De...

Method for the concurrent ultrasonic inspection of partially completed welds

DOEpatents

Johnson, John A.; Larsen, Eric D.; Miller, Karen S.; Smartt, Herschel B.; McJunkin, Timothy R.

2002-01-01

A method for the concurrent ultrasonic inspection of partially completed welds is disclosed and which includes providing a pair of transducers which are individually positioned on the opposite sides of a partially completed weld to be inspected; moving the transducers along the length of and laterally inwardly and outwardly relative to the partially completed weld; pulsing the respective transducers to produce an ultrasonic signal which passes through or is reflected from the partially completed weld; receiving from the respective transducers ultrasonic signals which pass through or are reflected from the partially completed welds; and analyzing the ultrasonic signal which has passed through or is reflected from the partially completed weld to determine the presence of any weld defects.

Ultrasonic inspection and deployment apparatus

DOEpatents

Michaels, Jennifer E.; Michaels, Thomas E.; Mech, Jr., Stephen J.

1984-01-01

An ultrasonic inspection apparatus for the inspection of metal structures, especially installed pipes. The apparatus combines a specimen inspection element, an acoustical velocity sensing element, and a surface profiling element, all in one scanning head. A scanning head bellows contains a volume of oil above the pipe surface, serving as acoustical couplant between the scanning head and the pipe. The scanning head is mounted on a scanning truck which is mobile around a circular track surrounding the pipe. The scanning truck has sufficient motors, gears, and position encoders to allow the scanning head six degrees of motion freedom. A computer system continually monitors acoustical velocity, and uses that parameter to process surface profiling and inspection data. The profiling data is used to automatically control scanning head position and alignment and to define a coordinate system used to identify and interpret inspection data. The apparatus is suitable for highly automated, remote application in hostile environments, particularly high temperature and radiation areas.

Enhancement of submarine pressure hull steel ultrasonic inspection using imaging and artificial intelligence

NASA Astrophysics Data System (ADS)

Hay, D. Robert; Brassard, Michel; Matthews, James R.; Garneau, Stephane; Morchat, Richard

1995-06-01

The convergence of a number of contemporary technologies with increasing demands for improvements in inspection capabilities in maritime applications has created new opportunities for ultrasonic inspection. An automated ultrasonic inspection and data collection system APHIUS (automated pressure hull intelligent ultrasonic system), incorporates hardware and software developments to meet specific requirements for the maritime vessels, in particular, submarines in the Canadian Navy. Housed within a hardened portable computer chassis, instrumentation for digital ultrasonic data acquisition and transducer position measurement provide new capabilities that meet more demanding requirements for inspection of the aging submarine fleet. Digital data acquisition enables a number of new important capabilites including archiving of the complete inspection session, interpretation assistance through imaging, and automated interpretation using artificial intelligence methods. With this new reliable inspection system, in conjunction with a complementary study of the significance of real defect type and location, comprehensive new criteria can be generated which will eliminate unnecessary defect removal. As a consequence, cost savings will be realized through shortened submarine refit schedules.

Evolution of the Ultrasonic Inspection Requirements of Heavy Rotor Forgings Over the Past Decades

NASA Astrophysics Data System (ADS)

Vrana, J.; Zimmer, A.; Bailey, K.; Angal, R.; Zombo, P.; Büchner, U.; Buschmann, A.; Shannon, R. E.; Lohmann, H.-P.; Heinrich, W.

2010-02-01

Heavy rotor forgings for land-based power generation turbines and generators are inspected ultrasonically. Several decades ago the first inspections were conducted using manual, straight beam, contact transducers with simple, non-descript reporting requirements. The development of ultrasonic inspection capabilities, the change in design engineer requirements, improvements of fracture mechanics calculations, experience with turbine operation, experience with the inspection technology, and probability of detection drove the changes that have resulted in the current day inspection requirements: sizing technologies were implemented, detection limits were lowered, angle and pitch/catch (dual crystal) scans were introduced, and most recently automated equipment for the inspection was required. Due to all these changes, model based sizing techniques, like DGS, and modern ultrasonic techniques, like phased array, are being introduced globally. This paper describes the evolution of the ultrasonic inspection requirements over the last decades and presents an outlook for tomorrow.

Ultrasonic probe deployment device for increased wave transmission and rapid area scan inspections

DOEpatents

DiMambro, Joseph; Roach, Dennis P; Rackow, Kirk A; Nelson, Ciji L; Dasch, Cameron J; Moore, David G

2013-02-12

An ultrasonic probe deployment device in which an ultrasound-transmitting liquid forms the portion of the ultrasonic wave path in contact with the surface being inspected (i.e., the inspection surface). A seal constrains flow of the liquid, for example preventing the liquid from surging out and flooding the inspection surface. The seal is not rigid and conforms to variations in the shape and unevenness of the inspection surface, thus forming a seal (although possibly a leaky seal) around the liquid. The probe preferably is held in place to produce optimum ultrasonic focus on the area of interest. Use of encoders can facilitate the production of C-scan area maps of the material being inspected.

Ultrasonic probe deployment device for increased wave transmission and rapid area scan inspections

DOEpatents

DiMambro, Joseph [Placitas, NM; Roach, Dennis P [Albuquerque, NM; Rackow, Kirk A [Albuquerque, NM; Nelson, Ciji L [Albuquerque, NM; Dasch, Cameron J [Boomfield Hills, MI; Moore, David G [Albuquerque, NM

2012-01-03

An ultrasonic probe deployment device in which an ultrasound-transmitting liquid forms the portion of the ultrasonic wave path in contact with the surface being inspected (i.e., the inspection surface). A seal constrains flow of the liquid, for example preventing the liquid from surging out and flooding the inspection surface. The seal is not rigid and conforms to variations in the shape and unevenness of the inspection surface, thus forming a seal (although possibly a leaky seal) around the liquid. The probe preferably is held in place to produce optimum ultrasonic focus on the area of interest. Use of encoders can facilitate the production of C-scan area maps of the material being inspected.

Flexible ultrasonic pipe inspection apparatus

DOEpatents

Jenkins, C.F.; Howard, B.D.

1998-06-23

A flexible, modular ultrasonic pipe inspection apparatus, comprises a flexible, hollow shaft that carries a plurality of modules, including at least one rotatable ultrasonic transducer, a motor/gear unit, and a position/signal encoder. The modules are connected by flexible knuckle joints that allow each module of the apparatus to change its relative orientation with respect to a neighboring module, while the shaft protects electrical wiring from kinking or buckling while the apparatus moves around a tight corner. The apparatus is moved through a pipe by any suitable means, including a tether or drawstring attached to the nose or tail, differential hydraulic pressure, or a pipe pig. The rotational speed of the ultrasonic transducer and the forward velocity of the apparatus are coordinated so that the beam sweeps out the entire interior surface of the pipe, enabling the operator to accurately assess the condition of the pipe wall and determine whether or not leak-prone corrosion damage is present. 7 figs.

Flexible ultrasonic pipe inspection apparatus

DOEpatents

Jenkins, Charles F.; Howard, Boyd D.

1998-01-01

A flexible, modular ultrasonic pipe inspection apparatus, comprising a flexible, hollow shaft that carries a plurality of modules, including at least one rotatable ultrasonic transducer, a motor/gear unit, and a position/signal encoder. The modules are connected by flexible knuckle joints that allow each module of the apparatus to change its relative orientation with respect to a neighboring module, while the shaft protects electrical wiring from kinking or buckling while the apparatus moves around a tight corner. The apparatus is moved through a pipe by any suitable means, including a tether or drawstring attached to the nose or tail, differential hydraulic pressure, or a pipe pig. The rotational speed of the ultrasonic transducer and the forward velocity of the apparatus are coordinated so that the beam sweeps out the entire interior surface of the pipe, enabling the operator to accurately assess the condition of the pipe wall and determine whether or not leak-prone corrosion damage is present.

Guide for inservice inspection of ground-based pressure vessels and systems

NASA Technical Reports Server (NTRS)

1976-01-01

This guide includes recommendations for inservice inspection and recertification of ground based, unfired pressure vessels and all pressurized systems including those served by fired pressure vessels hereinafter referred to as pressure vessels, systems and components of systems. It covers the vast array of pound based industrial and special purpose pressurized components and systems used at NASA field installations for research and development and those utility systems and components that require more than routine maintenance to insure continued structural integrity for their useful life. Through surveillance and correction of inservice deterioration, NASA will maintain a safe working environment for their own and contractor personnel, safety for the public sector and protection against loss of capital investment.

In-service Inspection of Radioactive Waste Tanks at the Savannah River Site – 15410

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

Wiersma, Bruce; Maryak, Matthew; Baxter, Lindsay

2015-01-12

Liquid radioactive wastes from the Savannah River Site (SRS) separation process are stored in large underground carbon steel tanks. The high level wastes are processed in several of the tanks and then transferred by piping to other site facilities for further processing before they are stabilized in a vitrified or grout waste form. Based on waste removal and processing schedules, many of the tanks will be required to be in service for times exceeding the initial intended life. Until the waste is removed from storage, transferred, and processed, the materials and structures of the tanks must maintain a confinement functionmore » by providing a barrier to the environment and by maintaining acceptable structural stability during design basis events, which include loadings from both normal service and abnormal (e.g., earthquake) conditions. A structural integrity program is in place to maintain the structural and leak integrity functions of these waste tanks throughout their intended service life. In-service inspection (ISI) is an essential element of a comprehensive structural integrity program for the waste tanks at the Savannah River Site (SRS). The ISI program was developed to determine the degree of degradation the waste tanks have experienced due to service conditions. As a result of the inspections, an assessment can be made of the effectiveness of corrosion controls for the waste chemistry, which precludes accelerated localized and general corrosion of the waste tanks. Ultrasonic inspections (UT) are performed to detect and quantify the degree of general wall thinning, pitting and cracking as a measure of tank degradation. The results from these inspections through 2013, for the 27 Type III/IIIA tanks, indicate no reportable in-service corrosion degradation in the primary tank (i.e., general, pitting, or cracking). The average wall thickness for all tanks remains above the manufactured nominal thickness minus 0.25 millimeter and the largest pit identified is

Finite element analysis simulations for ultrasonic array NDE inspections

NASA Astrophysics Data System (ADS)

Dobson, Jeff; Tweedie, Andrew; Harvey, Gerald; O'Leary, Richard; Mulholland, Anthony; Tant, Katherine; Gachagan, Anthony

2016-02-01

Advances in manufacturing techniques and materials have led to an increase in the demand for reliable and robust inspection techniques to maintain safety critical features. The application of modelling methods to develop and evaluate inspections is becoming an essential tool for the NDE community. Current analytical methods are inadequate for simulation of arbitrary components and heterogeneous materials, such as anisotropic welds or composite structures. Finite element analysis software (FEA), such as PZFlex, can provide the ability to simulate the inspection of these arrangements, providing the ability to economically prototype and evaluate improved NDE methods. FEA is often seen as computationally expensive for ultrasound problems however, advances in computing power have made it a more viable tool. This paper aims to illustrate the capability of appropriate FEA to produce accurate simulations of ultrasonic array inspections - minimizing the requirement for expensive test-piece fabrication. Validation is afforded via corroboration of the FE derived and experimentally generated data sets for a test-block comprising 1D and 2D defects. The modelling approach is extended to consider the more troublesome aspects of heterogeneous materials where defect dimensions can be of the same length scale as the grain structure. The model is used to facilitate the implementation of new ultrasonic array inspection methods for such materials. This is exemplified by considering the simulation of ultrasonic NDE in a weld structure in order to assess new approaches to imaging such structures.

Ultrasonic probe for inspecting double-wall tube

DOEpatents

Cook, Kenneth V.; Cunningham, Jr., Robert A.; Murrin, Horace T.

1983-01-01

An ultrasonic probe for inspecting the interface between the walls of a double-wall tube comprises a cylindrical body member having two cavities axially spaced apart thereon. The probe is placed in the tube and ultrasonic energy is transmitted from a transducer in its body member to a reflector in one of its cavities and thence into the inner wall of the tube. A second transducer in the probe body member communicates with the second cavity through a collimation passage in the body member, and the amount of ultrasonic energy reflected from the interface between the walls of the tube to a second reflector through the collimation passage to the second transducer depends upon the characteristics of said interface.

Method and means of transmitting and receiving broad-band unipolar, ultrasonic pulses for ultrasonic inspection

DOEpatents

Thompson, Donald O.; Hsu, David K.

1993-12-14

The invention includes a means and method for transmitting and receiving broadband, unipolar, ultrasonic pulses for ultrasonic inspection. The method comprises generating a generally unipolar ultrasonic stress pulse from a low impedance voltage pulse transmitter along a low impedance electrical pathway to an ultrasonic transducer, and receiving the reflected echo of the pulse by the transducer, converting it to a voltage signal, and passing it through a high impedance electrical pathway to an output. The means utilizes electrical components according to the method. The means and method allow a single transducer to be used in a pulse/echo mode, and facilitates alternatingly transmitting and receiving the broadband, unipolar, ultrasonic pulses.

Ultrasonic angle beam standard reflector. [ultrasonic nondestructive inspection

NASA Technical Reports Server (NTRS)

Berry, R. F., Jr. (Inventor)

1985-01-01

A method that provides an impression profile in a reference standard material utilized in inspecting critically stressed components with pulsed ultrasound is described. A die stamp having an I letter is used to impress the surface of a reference material. The die stamp is placed against the surface and struck with an inertia imparting member to impress the I in the reference standard material. Upset may appear on the surface as a result of the impression and is removed to form a smooth surface. The stamping and upset removal is repeated until the entire surface area of a depth control platform on the die stamp uniformly contacts the material surface. The I impression profile in the reference standard material is utilized for reflecting pulsed ultrasonic beams for inspection purposes.

Assessment of state-of-the-art of in-service inspection methods for graphite epoxy composite structures on commercial transport aircraft

NASA Technical Reports Server (NTRS)

Phelps, M. L.

1979-01-01

A survey was conducted to determine current in-service inspection practices for all types of aircraft structure and particularly for advanced composite structures. The survey consisted of written questionnaires to commercial airlines, visits to airlines, aircraft manufacturers, and government agencies, and a literature search. Details of the survey including visits, questions asked, a bibliography of reviewed literature and details of the results are reported. From the results, a current in-service inspection baseline and a preliminary inspection program for advanced composite structures is documented as appendices to the report.

Compensating for Attenuation Differences in Ultrasonic Inspections of Titanium-Alloy Billets

NASA Astrophysics Data System (ADS)

Margetan, F. J.; Thompson, R. B.; Keller, Michael; Hassan, Waled

2004-02-01

Cylindrical billets of Titanium alloy are ultrasonically inspected prior to use in fabricating rotating jet-engine components. Although each billet has a cylindrical geometry, its ultrasonic properties are not cylindrically symmetric due to asymmetries in the process used to produce the billet from the original cast ingot. In the inspection process, a calibration standard of the same diameter containing flat-bottomed hole (FBH) reflectors is used to set the initial inspection gain (i.e., the signal amplification level). If the ultrasonic attenuation of the billet to be inspected differs significantly from that of the calibration standard, the inspection gain must be adjusted to maintain the desired defect detection sensitivity. In this paper we investigate several schemes for attenuation compensation. The gain adjustments fall into two broad categories: "global" adjustments (in dB/inch units), which are applied uniformly throughout the billet under inspection; and "local adjustments", which vary with axial and circumferential position. The schemes make use of the patterns of reflected back-wall amplitude and backscattered grain noise seen in the calibration standard and test billet. The various compensation schemes are tested using specimens of 6″-diameter Ti-6A1-4V billet into which many FBH targets were drilled. Results are summarized and tentative recommendations for improving billet inspection practices are offered.

Sensitivity images for multi-view ultrasonic array inspection

NASA Astrophysics Data System (ADS)

Budyn, Nicolas; Bevan, Rhodri; Croxford, Anthony J.; Zhang, Jie; Wilcox, Paul D.; Kashubin, Artem; Cawley, Peter

2018-04-01

The multi-view total focusing method (TFM) is an imaging technique for ultrasonic full matrix array data that typically exploits ray paths with zero, one or two internal reflections in the inspected object and for all combinations of longitudinal and transverse modes. The fusion of this vast quantity of views is expected to increase the reliability of ultrasonic inspection; however, it is not trivial to determine which views and which areas are the most suited for the detection of a given type and orientation of defect. This work introduces sensitivity images that give the expected response of a defect in any part of the inspected object and for any view. These images are based on a ray-based analytical forward model. They can be used to determine which views and which areas lead to the highest probability of detection of the defect. They can also be used for quantitatively analyzing the effects of the parameters of the inspection (probe angle and position, for example) on the overall probability of detection. Finally, they can be used to rescale TFM images so that the different views have comparable amplitudes. This methodology is applied to experimental data and discussed.

Method and means of transmitting and receiving broad-band unipolar, ultrasonic pulses for ultrasonic inspection

DOEpatents

Thompson, D.O.; Hsu, D.K.

1993-12-14

The invention includes a means and method for transmitting and receiving broadband, unipolar, ultrasonic pulses for ultrasonic inspection. The method comprises generating a generally unipolar ultrasonic stress pulse from a low impedance voltage pulse transmitter along a low impedance electrical pathway to an ultrasonic transducer, and receiving the reflected echo of the pulse by the transducer, converting it to a voltage signal, and passing it through a high impedance electrical pathway to an output. The means utilizes electrical components according to the method. The means and method allow a single transducer to be used in a pulse/echo mode, and facilitates alternatingly transmitting and receiving the broadband, unipolar, ultrasonic pulses. 25 figures.

Comparison of Pre and Post Road Test Ultrasonic Inspection Results on 134 Passenger Tires

DOT National Transportation Integrated Search

1979-11-01

A study was conducted to compare ultrasonic inspection data from 134 tires prior and subsequent to road tests in order to determine whether excessive tread wear could be related to characteristics detected by the ultrasonic inspection. Analysis of da...

Floating Ultrasonic Transducer Inspection System and Method for Nondestructive Evaluation

NASA Technical Reports Server (NTRS)

Johnston, Patrick H. (Inventor); Zalameda, Joseph N. (Inventor)

2016-01-01

A method for inspecting a structural sample using ultrasonic energy includes positioning an ultrasonic transducer adjacent to a surface of the sample, and then transmitting ultrasonic energy into the sample. Force pulses are applied to the transducer concurrently with transmission of the ultrasonic energy. A host machine processes ultrasonic return pulses from an ultrasonic pulser/receiver to quantify attenuation of the ultrasonic energy within the sample. The host machine detects a defect in the sample using the quantified level of attenuation. The method may include positioning a dry couplant between an ultrasonic transducer and the surface. A system includes an actuator, an ultrasonic transducer, a dry couplant between the transducer the sample, a scanning device that moves the actuator and transducer, and a measurement system having a pulsed actuator power supply, an ultrasonic pulser/receiver, and a host machine that executes the above method.

Ultrasonic inspection of carbon fiber reinforced plastic by means of sample-recognition methods

NASA Technical Reports Server (NTRS)

Bilgram, R.

1985-01-01

In the case of carbon fiber reinforced plastic (CFRP), it has not yet been possible to detect nonlocal defects and material degradation related to aging with the aid of nondestructive inspection method. An approach for overcoming difficulties regarding such an inspection involves an extension of the ultrasonic inspection procedure on the basis of a use of signal processing and sample recognition methods. The basic concept involved in this approach is related to the realization that the ultrasonic signal contains information regarding the medium which is not utilized in conventional ultrasonic inspection. However, the analytical study of the phyiscal processes involved is very complex. For this reason, an empirical approach is employed to make use of the information which has not been utilized before. This approach uses reference signals which can be obtained with material specimens of different quality. The implementation of these concepts for the supersonic inspection of CFRP laminates is discussed.

Transducer Modules for Dry-Coupled Ultrasonic Inspection of Aircraft Structures

NASA Astrophysics Data System (ADS)

Komsky, Igor N.

2004-02-01

Several types of transducer modules have been developed at Northwestern University to overcome the problems that are associated with the application of liquid or gel couplants. The modules deploy polymer films to transmit the ultrasound through a dry interface. These films are very flexible, so even with a low pressure they can be adapted to the irregular inspection surfaces. The dry-coupled transducer modules may be used for transmission and reception of both longitudinal and transverse ultrasonic waves in the MHz frequency range. The prototype modules have been integrated with the portable ultrasonic inspection units and tested on a number of aircraft structures.

Phased Array Probe Optimization for the Inspection of Titanium Billets

NASA Astrophysics Data System (ADS)

Rasselkorde, E.; Cooper, I.; Wallace, P.; Lupien, V.

2010-02-01

The manufacturing process of titanium billets can produce multiple sub-surface defects that are particularly difficult to detect during the early stages of production. Failure to detect these defects can lead to subsequent in-service failure. A new and novel automated quality control system is being developed for the inspection of titanium billets destined for use in aerospace applications. The sensors will be deployed by an automated system to minimise the use of manual inspections, which should improve the quality and reliability of these critical inspections early on in the manufacturing process. This paper presents the first part of the work, which is the design and the simulation of the phased array ultrasonic inspection of the billets. A series of phased array transducers were designed to optimise the ultrasonic inspection of a ten inch diameter billet made from Titanium 6Al-4V. A comparison was performed between different probes including a 2D annular sectorial array.

In-service Inspection Ultrasonic Testing of Reactor Pressure Vessel Welds for Assessing Flaw Density and Size Distribution per 10 CFR 50.61a, Alternate Fracture Toughness Requirements

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

Sullivan, Edmund J.; Anderson, Michael T.; Norris, Wallace

2012-09-17

bounded by the flaw density and size distribution values used in the PTS technical basis. Under a contract with the NRC, Pacific Northwest National Laboratory (PNNL) has been working on a program to assess the ability of current inservice inspection (ISI)-ultrasonic testing (UT) techniques, as qualified through ASME Code, Appendix VIII, Supplements 4 and 6, to detect small fabrication or inservice-induced flaws located in RPV welds and adjacent base materials. As part of this effort, the investigators have pursued an evaluation, based on the available information, of the capability of UT to provide flaw density/distribution inputs for making RPV weld assessments in accordance with §50.61a. This paper presents the results of an evaluation of data from the 1993 Browns Ferry Nuclear Plant, Unit 3, Spirit of Appendix VIII reactor vessel examination, a comparison of the flaw density/distribution from this data with the distribution in §50.61a, possible reasons for differences, and plans and recommendations for further work in this area.« less

Ultrasonic guided wave inspection of Inconel 625 brazed lap joints

NASA Astrophysics Data System (ADS)

Comot, Pierre; Bocher, Philippe; Belanger, Pierre

2016-04-01

The aerospace industry has been investigating the use of brazing for structural joints, as a mean of reducing cost and weight. There therefore is a need for a rapid, robust, and cost-effective non-destructive testing method for evaluating the structural integrity of the joints. The mechanical strength of brazed joints depends mainly on the amount of brittle phases in their microstructure. Ultrasonic guided waves offer the possibility of detecting brittle phases in joints using spatio-temporal measurements. Moreover, they offer the opportunity to inspect complex shape joints. This study focused on the development of a technique based on ultrasonic guided waves for the inspection of Inconel 625 lap joints brazed with BNi-2 filler metal. A finite element model of a lap joint was used to optimize the inspection parameters and assess the feasibility of detecting the amount of brittle phases in the joint. A finite element parametric study simulating the input signal shape, the center frequency, and the excitation direction was performed. The simulations showed that the ultrasonic guided wave energy transmitted through, and reflected from, the joints was proportional to the amount of brittle phases in the joint.

Ultrasonic probe system for the bore-side inspection of tubes and welds therein

DOEpatents

Cook, K. Von; Koerner, Dan W.; Cunningham, Jr., Robert A.; Murrin, Jr., Horace T.

1977-07-26

A probe system is provided for the bore-side inspection of tube-to-header welds and the like for small diameter tubes. The probe head of the system includes an ultrasonic transmitter-receiver transducer, a separate ultrasonic receiver, a reflector associated with the transducer to properly orient the ultrasonic signal with respect to a tube wall, a baffle to isolate the receiver from the transducer, and means for maintaining the probe head against the tube wall under investigation. Since the probe head must rotate to inspect along a helical path, special ultrasonic signal connections are employed. Through the use of the probe, flaws at either the inner or outer surfaces may be detected.

Rolling dry-coupled transducers for ultrasonic inspections of aging aircraft structures

NASA Astrophysics Data System (ADS)

Komsky, Igor N.

2004-07-01

Some advanced aircraft materials or coatings are porous or otherwise sensitive to the application of water, gel, or some other ultrasonic couplants. To overcome the problems associated with the liquid coupling medium, dry-coupled rolling modules were developed at Northwestern University for the transmission of both longitudinal and transverse ultrasonic waves at frequencies up to 10 MHz. Dry-coupled ultrasonic modules contain solid core internal stators and solid or flexible external rotors with the flexible polymer substrates. Two types of the dry-coupled modules are under development. Cylindrical base transducer modules include solid core cylindrical rotors with flexible polymer substrates that rotate around the stators with ultrasonic elements. Dry-coupled modules with elongated bases contain solid core stators and flexible track-like polymer substrates that rotate around the stators as rotors of the modules. The elongated base modules have larger contact interfaces with the inspection surface in comparison with the cylindrical base modules. Some designs of the dry-coupled rolling modules contain several ultrasonic elements with different incident angles or a variable angle unit for rapid adjustments of incident angles. The prototype dry-coupled rolling modules were integrated with the portable ultrasonic inspection systems and tested on a number of Boeing aircraft structures.

A Portable Ultrasonic Nondestructive Inspection System for Metal Matrix Composite Track Shoes

NASA Astrophysics Data System (ADS)

Mi, Bao; Zhao, Xiaoliang; Qian, Tao; Stevenson, Mark; Kwan, Chiman; Owens, Steven E.; Royer, Roger L.; Tittmann, Bernhard R.; Raju, Basavaraju B.

2007-03-01

Cast aluminum track shoes reinforced with metal matrix composite (MMC) inserts at heavy loading areas such as center splines and sprocket windows are light in weight, and can resist high temperature and wear. Various defects such as disbonds at the insert-substrate interface, cracks and porosity in the MMC layer, etc. can be introduced during the manufacturing process and/or in service. This paper presents a portable ultrasonic system to automatically inspect tank track shoes for disbond. Ultrasonic pulse/echo inspection has shown good reliability for disbond detection. A prototype sensor array fixture has been designed and fabricated to prove the feasibility. Good agreements between the sensor fixture results and ultrasonic C-scan images were obtained.

Low frequency ultrasonic nondestructive inspection of aluminum/adhesive fuselage lap splices

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

Patton, Thadd

1994-01-04

This thesis is a collection of research efforts in ultrasonics, conducted at the Center for Aviation Systems Reliability located at Iowa State University, as part of the Federal Aviation Administration`s ``Aging Aircraft Program.`` The research was directed toward the development of an ultrasonic prototype to inspect the aluminum/adhesive fuselage lap splices found on 1970`s vintage Boeing passenger aircraft. The ultrasonic prototype consists of a normal incidence, low frequency inspection technique, and a scanning adapter that allows focused immersion transducers to be operated in a direct contact manner in any inspection orientation, including upside-down. The inspection technique uses a computer-controlled datamore » acquisition system to produce a C-scan image of a radio frequency (RF) waveform created by a low frequency, broadband, focused beam transducer, driven with a spike voltage pulser. C-scans produced by this technique are color representations of the received signal`s peak-to-peak amplitude (voltage) taken over an (x, y) grid. Low frequency, in this context, refers to a wavelength that is greater than the lap splice`s layer thicknesses. With the low frequency technique, interface echoes of the lap splice are not resolved and gating of the signal is unnecessary; this in itself makes the technique simple to implement and saves considerable time in data acquisition. Along with the advantages in data acquisition, the low frequency technique is relatively insensitive to minor surface curvature and to ultrasonic interference effects caused by adhesive bondline thickness variations in the lap splice.« less

Ultrasonic Phased Array Inspection for an Isogrid Structural Element with Cracks

NASA Technical Reports Server (NTRS)

Roth, D. J.; Tokars, R. P.; Martin, R. E.; Rauser, R. W.; Aldrin, J. C.; Schumacher, E. J.

2010-01-01

In this investigation, a T-shaped aluminum alloy isogrid stiffener element used in aerospace applications was inspected with ultrasonic phased array methods. The isogrid stiffener element had various crack configurations emanating from bolt holes. Computational simulation methods were used to mimic the experiments in order to help understand experimental results. The results of this study indicate that it is at least partly feasible to interrogate this type of geometry with the given flaw configurations using phased array ultrasonics. The simulation methods were critical in helping explain the experimental results and, with some limitation, can be used to predict inspection results.

Ultrasonic Phased Array Inspection Simulations of Welded Components at NASA

NASA Technical Reports Server (NTRS)

Roth, D. J.; Tokars, R. P.; Martin, R. E.; Rauser, R. W.; Aldrin, J. C.; Schumacher, E. J.

2009-01-01

Comprehensive and accurate inspections of welded components have become of increasing importance as NASA develops new hardware such as Ares rocket segments for future exploration missions. Simulation and modeling will play an increased role in the future for nondestructive evaluation in order to better understand the physics of the inspection process and help explain the experimental results. It will also help to prove or disprove the feasibility for an inspection method or inspection scenario, help optimize inspections, and allow to a first approximation limits of detectability. This study presents simulation and experimental results for an ultrasonic phased array inspection of a critical welded structure important for NASA future exploration vehicles.

Evolution of the Ultrasonic Inspection of Heavy Rotor Forgings Over the Last Decades

NASA Astrophysics Data System (ADS)

Zimmer, A.; Vrana, J.; Meiser, J.; Maximini, W.; Blaes, N.

2010-02-01

All types of heavy forgings that are used in energy machine industry, rotor shafts as well as discs, retaining rings or tie bolts are subject to extensive nondestructive inspections before they are delivered to the customer. Due to the availability of the parts in simple shapes, these forgings are very well suited for full volmetric inspections using ultrasound. In the beginning, these inspections were carried out manually, using straight beam probes and analogue equipment. Higher requirements in reliability, efficiency, safety and power output in the machines have lead to higher requirements for the ultrasonic inspection in the form of more scanning directions, higher sensitivity demands and improved documentation means. This and the increasing use of high alloy materials for ever growing parts, increase the need for more and more sophisticated methods for testing the forgings. Angle scans and sizing technologies like DGS have been implemented, and for more than 15 years now, mechanized and automated inspections have gained importance since they allow better documentation as well as easier evaluation of the recorded data using different views (B- C- or D-Scans), projections or tomography views. The latest major development has been the availability of phased array probes to increase the flexibility of the inspection systems. Many results of the ongoing research in ultrasonic's have not been implemented yet. Today's availability of fast computers, large and fast data storages allows saving RF inspection data and applying sophisticated signal processing methods. For example linear diffraction tomography methods like SAFT offer tools for 3D reconstruction of inspection data, simplifying sizing and locating of defects as well as for improving signal to noise ratios. While such methods are already applied in medical ultrasonic's, they are still to be implemented in the steel industry. This paper describes the development of the ultrasonic inspection of heavy forgings

Ultrasonic probe for inspecting double-wall tube. [Patent application

DOEpatents

Cook, K.V.; Cunningham, R.A. Jr.; Murrin, H.T.

1981-05-29

An ultrasonic probe for inspecting the interface between the walls of a double-wall tube comprises a cylindrical body member having two cavities axially spaced apart thereon. The probe is placed in the tube and ultrasonic energy is transmitted from a transducer in its body member to a reflector in one of its cavities and thence into the inner wall of the tube. A second transducer in the probe body member communicates with the second cavity through a collimation passage in the body member, and the amount of ultrasonic energy reflected from the interface between the walls of the tube to a second reflector through the collimation passage to the second transducer depends upon the characteristics of said interface.

Ultrasonic technique for inspection of GPHS capsule girth weld integrity

NASA Astrophysics Data System (ADS)

Placr, Arnost

1993-05-01

An innovative nondestructive examination (NDE) technique for the inspection of integrity of General Purpose Heat Source (GPHS) capsule girth welds was developed employing a Lamb wave as the mode of the sound propagation. Reliability of the Lamb wave technique was tested on GPHS capsules using plutonium pallet simulators. All ten capsules, which were previously rejected, passed ultrasonic (UT) inspection using the Lamb wave technique.

Laser-ultrasonic inspection of hybrid laser-arc welded HSLA-65 steel

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

Lévesque, D.; Rousseau, G.; Monchalin, J.-P.

2014-02-18

The hybrid laser-arc welding (HLAW) process is a relatively low heat input joining technology that combines the synergistic qualities of both the high energy density laser beam for deep penetration and the arc for wide fit-up gap tolerance. This process is especially suitable for the shipbuilding industry where thick-gauge section, long steel plates have been widely used in a butt joint configuration. In this study, preliminary exploration was carried out to detect and visualize the welding defects using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). Results obtained on 9.3 mm thick butt-welded HSLA-65 steel plates indicated thatmore » the laser-ultrasonic SAFT inspection technique can successfully detect and visualize the presence of porosity, lack of fusion and internal crack defects. This was further confirmed by X-ray digital radiography and metallography. The results obtained clearly show the potential of using the laser-ultrasonic technology for the automated inspection of hybrid laser-arc welds.« less

Laser-ultrasonic inspection of hybrid laser-arc welded HSLA-65 steel

NASA Astrophysics Data System (ADS)

Lévesque, D.; Rousseau, G.; Wanjara, P.; Cao, X.; Monchalin, J.-P.

2014-02-01

The hybrid laser-arc welding (HLAW) process is a relatively low heat input joining technology that combines the synergistic qualities of both the high energy density laser beam for deep penetration and the arc for wide fit-up gap tolerance. This process is especially suitable for the shipbuilding industry where thick-gauge section, long steel plates have been widely used in a butt joint configuration. In this study, preliminary exploration was carried out to detect and visualize the welding defects using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). Results obtained on 9.3 mm thick butt-welded HSLA-65 steel plates indicated that the laser-ultrasonic SAFT inspection technique can successfully detect and visualize the presence of porosity, lack of fusion and internal crack defects. This was further confirmed by X-ray digital radiography and metallography. The results obtained clearly show the potential of using the laser-ultrasonic technology for the automated inspection of hybrid laser-arc welds.

High temperature ultrasonic immersion measurements using a BS-PT based piezoelectric transducer without a delay line

NASA Astrophysics Data System (ADS)

Bilgunde, Prathamesh N.; Bond, Leonard J.

2018-04-01

Ultrasonic imaging is a key enabling technology required for in-service inspection of advanced sodium fast reactors at the hot stand-by operating mode (˜250C). Current work presents development of a single element, 2.4MHz, planar, ultrasonic immersion transducer for a potential application in ranging, inspection and imaging of the reactor components. The prototype immersion transducer is first tested in water for three thermal cycles up to 92C. The transducer is further evaluated for four thermal cycles in silicone oil, with total seven thermal cycles that exceeded operation period of 21 hours. Moreover, the preliminary data acquired for speed of sound in silicone oil indicates 24% reduction from 22C to 142C. Sensitivity of the ultrasonic transducer is also measured as a function of temperature and demonstrates the effect of multiple thermal cycles on the transducer components.

Internal Stress Monitoring of In-Service Structural Steel Members with Ultrasonic Method

PubMed Central

Li, Zuohua; He, Jingbo; Teng, Jun; Wang, Ying

2016-01-01

Internal stress in structural steel members is an important parameter for steel structures in their design, construction, and service stages. However, it is hard to measure via traditional approaches. Among the existing non-destructive testing (NDT) methods, the ultrasonic method has received the most research attention. Longitudinal critically refracted (Lcr) waves, which propagate parallel to the surface of the material within an effective depth, have shown great potential as an effective stress measurement approach. This paper presents a systematic non-destructive evaluation method to determine the internal stress in in-service structural steel members using Lcr waves. Based on theory of acoustoelasticity, a stress evaluation formula is derived. Factor of stress to acoustic time difference is used to describe the relationship between stress and measurable acoustic results. A testing facility is developed and used to demonstrate the performance of the proposed method. Two steel members are measured by using the proposed method and the traditional strain gauge method for verification. Parametric studies are performed on three steel members and the aluminum plate to investigate the factors that influence the testing results. The results show that the proposed method is effective and accurate for determining stress in in-service structural steel members. PMID:28773347

Internal Stress Monitoring of In-Service Structural Steel Members with Ultrasonic Method.

PubMed

Li, Zuohua; He, Jingbo; Teng, Jun; Wang, Ying

2016-03-23

Internal stress in structural steel members is an important parameter for steel structures in their design, construction, and service stages. However, it is hard to measure via traditional approaches. Among the existing non-destructive testing (NDT) methods, the ultrasonic method has received the most research attention. Longitudinal critically refracted (Lcr) waves, which propagate parallel to the surface of the material within an effective depth, have shown great potential as an effective stress measurement approach. This paper presents a systematic non-destructive evaluation method to determine the internal stress in in-service structural steel members using Lcr waves. Based on theory of acoustoelasticity, a stress evaluation formula is derived. Factor of stress to acoustic time difference is used to describe the relationship between stress and measurable acoustic results. A testing facility is developed and used to demonstrate the performance of the proposed method. Two steel members are measured by using the proposed method and the traditional strain gauge method for verification. Parametric studies are performed on three steel members and the aluminum plate to investigate the factors that influence the testing results. The results show that the proposed method is effective and accurate for determining stress in in-service structural steel members.

Simulation assisted pod of a phased array ultrasonic inspection in manufacturing

NASA Astrophysics Data System (ADS)

Dominguez, N.; Feuillard, V.; Jenson, F.; Willaume, P.

2012-05-01

The concept of Probability of Detection (POD) is generally used to quantitatively assess performances and reliability of NDT operations for in-service operations related to damage tolerant designs. Application of the POD approach as a metric for manufacturing NDT assessment would also be relevant but the very expensive cost of such campaigns generally prevents us from doing so. However the increase in NDT simulation capability and maturity opens the field for POD demonstrations for manufacturing NDT with the help of simulation. This paper presents the example of an automated phased array ultrasonic testing procedure of Electron Beam Welding on rotative parts, as part of the PICASSO European project. POD is calculated by using the uncertainty propagation approach in CIVA. The peculiarity of uncertainties in automated NDT compared to in-service manual operations is discussed and raises questions on appropriate statistics to be used for this kind of data. Alternative estimation techniques like Box-Cox transform or quantile regression are proposed and evaluated.

Fundamental study of microelectronic chip response under laser ultrasonic-interferometric inspection using C-scan method

NASA Astrophysics Data System (ADS)

Yang, Lei; Gong, Jie; Ume, I. Charles

2014-02-01

In modern surface mount packaging technologies, such as flip chips, chip scale packages, and ball grid arrays(BGA), chips are attached to the substrates/printed wiring board (PWB) using solder bump interconnections. The quality of solder bumps between the chips and the substrate/board is difficult to inspect. Laser ultrasonic-interferometric technique was proved to be a promising approach for solder bump inspection because of its noncontact and nondestructive characteristics. Different indicators extracted from received signals have been used to predict the potential defects, such as correlation coefficient, error ratio, frequency shifting, etc. However, the fundamental understanding of the chip behavior under laser ultrasonic inspection is still missing. Specifically, it is not sure whether the laser interferometer detected out-of-plane displacements were due to wave propagation or structural vibration when the chip was excited by pulsed laser. Plus, it is found that the received signals are chip dependent. Both challenges impede the interpretation of acquired signals. In this paper, a C-scan method was proposed to study the underlying phenomenon during laser ultrasonic inspection. The full chip was inspected. The response of the chip under laser excitation was visualized in a movie resulted from acquired signals. Specifically, a BGA chip was investigated to demonstrate the effectiveness of this method. By characterizing signals using discrete wavelet transform(DWT), both ultrasonic wave propagation and vibration were observed. Separation of them was successfully achieved using ideal band-pass filter and visualized in resultant movies, too. The observed ultrasonic waves were characterized and their respective speeds were measured by applying 2-D FFT. The C-scan method, combined with different digital signal processing techniques, was proved to be an very effective methodology to learn the behavior of chips under laser excitation. This general procedure can be

Advance High Temperature Inspection Capabilities for Small Modular Reactors: Part 1 - Ultrasonics

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

Bond, Leonard J.; Bowler, John R.

The project objective was to investigate the development non-destructive evaluation techniques for advanced small modular reactors (aSMR), where the research sought to provide key enabling inspection technologies needed to support the design and maintenance of reactor component performance. The project tasks for the development of inspection techniques to be applied to small modular reactor are being addressed through two related activities. The first is focused on high temperature ultrasonic transducers development (this report Part 1) and the second is focused on an advanced eddy current inspection capability (Part 2). For both inspection techniques the primary aim is to develop in-servicemore » inspection techniques that can be carried out under standby condition in a fast reactor at a temperature of approximately 250°C in the presence of liquid sodium. The piezoelectric material and the bonding between layers have been recognized as key factors fundamental for development of robust ultrasonic transducers. Dielectric constant characterization of bismuth scantanate-lead titanate ((1-x)BiScO 3-xPbTiO 3) (BS-PT) has shown a high Curie temperature in excess of 450°C , suitable for hot stand-by inspection in liquid metal reactors. High temperature pulse-echo contact measurements have been performed with BS-PT bonded to 12.5 mm thick 1018-low carbon steel plate from 20C up to 260 C. High temperature air-backed immersion transducers have been developed with BS-PT, high temperature epoxy and quarter wavlength nickel plate, needed for wetting ability in liquid sodium. Ultrasonic immersion measurements have been performed in water up to 92C and in silicone oil up to 140C. Physics based models have been validated with room temperature experimental data with benchmark artifical defects.« less

LASERUT® Technology Development Programs for the Ultrasonic Inspection of Composites in the Aerospace Industry

NASA Astrophysics Data System (ADS)

Dubois, Marc; Drake, Thomas; Osterkamp, Mark; Yawn, Ken; Kaiser, David; Do, Tho; Maestas, Jeff; Thomas, Michael

2008-02-01

A laser-ultrasonic technique developed at Lockheed Martin Aeronautics called LaserUT® is used for the ultrasonic inspection of composite parts in the aeronautic industry and has demonstrated significant reduction in inspection labor and capital expenditure over approximately 20,000 parts so far. Development of new technologies will further increase LaserUT savings: structured-light mapping, improved CO2 laser, mid-infrared generation laser, and new robotic approach. Those different technologies are described and their status relatively to their introduction to production is discussed.

Portable Ultrasonic Guided Wave Inspection with MACRO Fiber Composite Actuators

NASA Astrophysics Data System (ADS)

Haig, A.; Mudge, P.; Catton, P.; Balachandran, W.

2010-02-01

The development of portable ultrasonic guided wave transducer arrays that utilize Macro Fiber Composite actuators (MFCs) is described. Portable inspection equipment can make use of ultrasonic guided waves to rapidly screen large areas of many types of engineering structures for defects. The defect finding performance combined with the difficulty of application determines how much the engineering industry makes use of this non-destructive, non-disruptive technology. The developments with MFCs have the potential to make considerable improvements in both these aspects. MFCs are highly efficient because they use interdigital electrodes to facilitate the extensional, d33 displacement mode. Their fiber composite design allows them to be thin, lightweight, flexible and durable. The flexibility affords them conformance with curved surfaces, which can facilitate good mechanical coupling. The suitability of a given transducer for Long Range Ultrasonic Testing is governed by the nature and amplitude of the displacement that it excites/senses in the contact area of the target structure. This nature is explored for MFCs through directional sensitivity analysis and empirical testing. Housing methods that facilitate non-permanent coupling techniques are discussed. Finally, arrangements of arrays of MFCs for the guided wave inspection of plates and pipes are considered and some broad design criteria are given.

A computerized self-compensating system for ultrasonic inspection of airplane structures

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

Komsky, I.N.; Achenbach, J.D.; Hagemaier, D.

1993-12-31

Application of a self-compensating technique for ultrasonic inspection of airplane structures makes it possible not only to detect cracks in the different layers of joints but also to obtain information on crack sizes. A prototype computerized ultrasonic system, which utilizes the self-compensating method, has been developed for non-destructive inspection of multilayered airplane structures with in-between sealants, such as bolted joints in tail connections. Industrial applications of the system would require deployment of commercially available portable modules for data acquisition and processing. A portable ultrasonic flaw detector EPOCH II manual scanners and HandiScan, and SQL and FCS software modules form themore » PC-based TestPro system have been selected for initial tests. A pair of contact angle-beam transducers were used to generate shear waves in the material. Both hardware and software components of the system have been modified for the application in conjunction with the self-compensating technique. The system has bene tested on two calibration specimens with artificial flaws of different sizes in internal layers of multilayered structures. Ultrasonic signals transmitted through and reflected from the artificial flaws have bene discriminated and characterized using multiple time domain amplitude gates. Then the ratios of the reflection and transmission coefficients, R/T, were calculated for several positions of the transducers. Inspection of measured R/T curves shows it is difficult to visually associate curve shapes with corresponding flaw sizes and orientation. Hence for online classification of these curve shapes, application of an adaptive signal classifier was considered. Several different types and configurations of the classifiers, including a neural network, have been tested. Test results showed that improved performance of the classifier can be achieved by combination of a back-propagation neural network with a signal pre-processing module.« less

Ultrasonic Phased Array Inspection Experiments and Simulations for AN Isogrid Structural Element with Cracks

NASA Astrophysics Data System (ADS)

Roth, D. J.; Tokars, R. P.; Martin, R. E.; Rauser, R. W.; Aldrin, J. C.; Schumacher, E. J.

2010-02-01

In this investigation, a T-shaped aluminum alloy isogrid stiffener element used in aerospace applications was inspected with ultrasonic phased array methods. The isogrid stiffener element had various crack configurations emanating from bolt holes. Computational simulation methods were used to mimic the experiments in order to help understand experimental results. The results of this study indicate that it is at least partly feasible to interrogate this type of geometry with the given flaw configurations using phased array ultrasonics. The simulation methods were critical in helping explain the experimental results and, with some limitation, can be used to predict inspection results.

Defect Inspection of Flip Chip Solder Bumps Using an Ultrasonic Transducer

PubMed Central

Su, Lei; Shi, Tielin; Xu, Zhensong; Lu, Xiangning; Liao, Guanglan

2013-01-01

Surface mount technology has spurred a rapid decrease in the size of electronic packages, where solder bump inspection of surface mount packages is crucial in the electronics manufacturing industry. In this study we demonstrate the feasibility of using a 230 MHz ultrasonic transducer for nondestructive flip chip testing. The reflected time domain signal was captured when the transducer scanning the flip chip, and the image of the flip chip was generated by scanning acoustic microscopy. Normalized cross-correlation was used to locate the center of solder bumps for segmenting the flip chip image. Then five features were extracted from the signals and images. The support vector machine was adopted to process the five features for classification and recognition. The results show the feasibility of this approach with high recognition rate, proving that defect inspection of flip chip solder bumps using the ultrasonic transducer has high potential in microelectronics packaging.

Prototype instrument for noninvasive ultrasonic inspection and identification of fluids in sealed containers

NASA Astrophysics Data System (ADS)

Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

2006-05-01

Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, handheld, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

Ultrasonic inspection and analysis techniques in green and dried lumber

Treesearch

Mark E. Schafer; Robert J. Ross; Brian K. Brashaw; Roy D. Adams

1999-01-01

Ultrasonic inspection of lumber has been under investigation for over 20 years, with little commercial impact. Recently, the USDA Forest Products Laboratory (FPL) developed ultrasound-based scanning technology to examine both green and dried lumber. In green lumber, the bacterial infection called wetwood (a significant source of degradation in oak at the kiln-drying...

Simultsonic: A Simulation Tool for Ultrasonic Inspection

NASA Astrophysics Data System (ADS)

Krishnamurthy, Adarsh; Karthikeyan, Soumya; Krishnamurthy, C. V.; Balasubramaniam, Krishnan

2006-03-01

A simulation program SIMULTSONIC is under development at CNDE to help determine and/or help optimize ultrasonic probe locations for inspection of complex components. SIMULTSONIC provides a ray-trace based assessment initially followed by a displacement or pressure field-based assessment for user-specified probe positions and user-selected component. Immersion and contact modes of inspection are available in SIMULTSONIC. The code written in Visual C++ operating in Microsoft Windows environment provides an interactive user interface. In this paper, the application of SIMULTSONIC to the inspection of very thin-walled pipes (with 450 um wall thickness) is described. Ray trace based assessment was done using SIMULTSONIC to determine the standoff distance and the angle of oblique incidence for an immersion mode focused transducer. A 3-cycle Hanning window pulse was chosen for simulations. Experiments were carried out to validate the simulations. The A-scans and the associated B-Scan images obtained through simulations show good correlation with experimental results, both with the arrival time of the signal as well as with the signal amplitudes. The scope of SIMULTSONIC to deal with parametrically represented surfaces will also be discussed.

Full-field ultrasonic inspection for a composite sandwich plate skin-core debonding detection using laser-based ultrasonics

NASA Astrophysics Data System (ADS)

Chong, See Yenn; Victor, Jared J.; Todd, Michael D.

2017-04-01

In this paper, a full-field ultrasonic guided wave method is proposed to inspect a composite sandwich specimen made for an aircraft engine nacelle. The back skin/core interface of the specimen is built with two fabricated disbond defects (diameters of 12.7 mm and 25.4 mm) by removing areas of the adhesive used to bond the back skin to the core. A laser ultrasonic interrogation system (LUIS) incorporated with a disbond detection algorithm is developed. The system consists of a 1-kHz laser ultrasonic scanning system and a single fixed ultrasonic sensor to interrogate ultrasonic guided waves in the sandwich specimen. The interest area of 400 mm × 400 mm is scanned at a 0.5 mm scan interval. The corresponding full-field ultrasonic data is obtained and generated in the three-dimensional (3-D) space-time domain. Then, the 3-D full-field ultrasonic data is Fourier transformed and the ultrasonic frequency spectra are analyzed to determine the dominant frequency that is sensitive to the disbond defects. Continuous wavelet transform (CWT) based on fast Fourier transform (FFT) is implemented as a single-frequency bandpass filter to filter the full-field ultrasonic data in the 3-D space-time domain at the selected dominant frequency. The LUIS has shown the ability to detect the disbond with diameters of 11 mm and 23 mm which match to the pre-determined disbond sizes well. For future research, a robust signal processing algorithm and a model-based matched filter will be investigated to make the detection process autonomous and improve detectability

Ultrasonic method for inspection of the propellant grain in the space shuttle solid rocket booster

NASA Astrophysics Data System (ADS)

Doyle, T. E.; Degtyar, A. D.; Sorensen, K. P.; Kelso, M. J.; Berger, T. A.

2000-05-01

Defects in solid rocket propellant may affect the safe operation of a space launch vehicle. The Space Shuttle reusable solid rocket motor (RSRM) is therefore routinely inspected with radiography for voids, cracks, and inclusions. Ultrasonic methods can be used to supplement radiography when an indication is difficult to interpret due to the projection geometry or low contrast. Such a method was developed to inspect a local region of propellant in an RSRM forward segment for a suspect inclusion. The method used a through-transmission approach, with a stationary transmitter on the propellant grain inside the segment and a receiving transducer scanned over the case surface. Low frequency (⩽250 kHz) pulses were propagated through 10-12 inches of propellant, 0.5 inches of NBR insulation, and 0.5 inches of steel case. Through-transmission images were constructed using time-of-flight analysis of the waveforms. The ultrasonic inspections supported results from extended radiographic studies, showing that the indication was not an inclusion but an artifact resulting from liner thickness variations and a low X-ray projection angle in the segment's dome region. This work demonstrated the feasibility of using ultrasonics for inspection of propellant grain in steel-cased rocket motors.

Development of an ultrasonic inspection robot using an electromagnetic acoustic transducer for a Lamb wave and an SH-plate wave.

PubMed

Murayama, Riichi; Makiyama, Shunnichi; Kodama, Mitutoshi; Taniguchi, Yasutoshi

2004-04-01

For inspection of a storage tank and pipeline in service, the application of an automatic inspection system (nondestructive inspection robot) is desirable, because manual inspection is difficult to perfectly and exactly perform due to the enormous amount of inspection needed. However, an ultrasonic nondestructive inspection robot with a piezoelectric oscillator needs to touch only the material surface to be directly inspected using a coupling medium. That is, the material surface and the sensor must always be held by constant pressure in the vertical direction on the material side. Actually, it is difficult to overcome these problems; thus an ultrasonic inspection robot could not be widely applied. We then tried to develop an ultrasonic inspection robot with an electromagnetic acoustic transducer (EMAT) which did not require a coupling medium to inspect the circumferential pipe parts. We developed a special EMAT that could transmit and receive alternately a Lamb wave with high sensitivity and a SH-plate wave without influence by the welded part. The method by which the inspection robot turned around the direction of the steel pipe surroundings was executed by observing the tape pasted in the direction of the steel pipe surroundings with an installed CCD camera. In this report, the basic mechanism of this inspection robot and an examination of results are described.

Pulse-Echo Phased Array Ultrasonic Inspection of Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS)

NASA Technical Reports Server (NTRS)

Johnston, Pat H.

2010-01-01

A PRSEUS test article was subjected to controlled impact on the skin face followed by static and cyclic axial compressions. Phased array ultrasonic inspection was conducted before impact, and after each of the test conditions. A linear phased array probe with a manual X-Y scanner was used for interrogation. Ultrasound showed a delamination between the skin and stringer flange adjacent to the impact. As designed, the stitching in the flange arrested the lateral flaw formation. Subsequent ultrasonic data showed no delamination growth due to continued loading. Keywords: Phased Array, Ultrasonics, Composites, Out-of-Autoclave

Nondestructive inspection of aerospace composites by a fiber-coupled laser ultrasonics system

NASA Astrophysics Data System (ADS)

Vandenrijt, J.-F.; Languy, F.; Thizy, C.; Georges, M. P.

2017-06-01

Laser ultrasonics is a technique currently studied for nondestructive inspection of aerospace composite structures based on carbon fibers. It combines a pulsed laser impacting the surface generates an ultrasound inside the material, through the nondestructive thermoelastic effect. Second a detection interferometer probes the impacted point in order to measure the displacement of the surface resulting from the emitted ultrasound wave and the echo coming back from the different interfaces of the structure. Laser ultrasonics is of interest for inspecting complex shaped composites. We have studied the possibility of using frequency doubled YAG laser for the generation and which is fiber-coupled, together with a fibercoupled interferometric probe using a YAG laser in the NIR. Our final system is a lightweight probe attached to a robot arm and which is able to scan complex shapes. The performances of the system are compared for different wavelengths of generations. Also we have studied some experimental parameters of interest such as tolerance to angle and focus distance, and different geometries of generation beams. We show some examples of inspection of reference parts with known defects. In particular C-scans of curved composites structures are presented.

Ultrasonic multi-skip tomography for pipe inspection

NASA Astrophysics Data System (ADS)

Volker, Arno; Vos, Rik; Hunter, Alan; Lorenz, Maarten

2012-05-01

The inspection of wall loss corrosion is difficult at pipe support locations due to limited accessibility. However, the recently developed ultrasonic Multi-Skip screening technique is suitable for this problem. The method employs ultrasonic transducers in a pitch-catch geometry positioned on opposite sides of the pipe support. Shear waves are transmitted in the axial direction within the pipe wall, reflecting multiple times between the inner and outer surfaces before reaching the receivers. Along this path, the signals accumulate information on the integral wall thickness (e.g., via variations in travel time). The method is very sensitive in detecting the presence of wall loss, but it is difficult to quantify both the extent and depth of the loss. If the extent is unknown, then only a conservative estimate of the depth can be made due to the cumulative nature of the travel time variations. Multi-Skip tomography is an extension of Multi-Skip screening and has shown promise as a complimentary follow-up inspection technique. In recent work, we have developed the technique and demonstrated its use for reconstructing high-resolution estimates of pipe wall thickness profiles. The method operates via a model-based full wave field inversion; this consists of a forward model for predicting the measured wave field and an iterative process that compares the predicted and measured wave fields and minimizes the differences with respect to the model parameters (i.e., the wall thickness profile). This paper presents our recent developments in Multi-Skip tomographic inversion, focusing on the initial localization of corrosion regions for efficient parameterization of the surface profile model and utilization of the signal phase information for improving resolution.

In-situ ultrasonic inspection of submarine shaft seal housing for corrosion damage

NASA Astrophysics Data System (ADS)

Batra, Narendra K.; Chaskelis, Henry H.; Mignogna, Richard B.

1995-06-01

The interior of the housings of primary and backup shaft seals of 637 class submarines are exposed to sea water during service and become corroded during service. Corrosion damage evaluation requires disassembly of the housing and visual inspection. In this paper, we present quantitative results of in situ nondestructive ultrasonic technique developed for the inspection of the seal housings. Due to vast variations in velocity in the seal material, the velocity was determined at suitable sites not subjected to corrosion and of known thickness from the blueprints. Using this normalized velocity and measured time-of-flight, we determined the thickness of the seal housing at various locations on the circumference. Subsequent mechanical thickness measurements, made when the housings were removed from service, agreed within the predicted uncertainty of 1.5% of ultrasonic measurements. This technique for the assessment of corrosion damage saves time and money, by preventing premature disassembly and downtime for the submarine.

Weld quality inspection using laser-EMAT ultrasonic system and C-scan method

NASA Astrophysics Data System (ADS)

Yang, Lei; Ume, I. Charles

2014-02-01

Laser/EMAT ultrasonic technique has attracted more and more interests in weld quality inspection because of its non-destructive and non-contact characteristics. When ultrasonic techniques are used to detect welds joining relative thin plates, the dominant ultrasonic waves present in the plates are Lamb waves, which propagate all through the thickness. Traditional Time of Flight(ToF) method loses its power. The broadband nature of laser excited ultrasound plus dispersive and multi-modal characteristic of Lamb waves make the EMAT acquired signals very complicated in this situation. Challenge rises in interpreting the received signals and establishing relationship between signal feature and weld quality. In this paper, the laser/EMAT ultrasonic technique was applied in a C-scan manner to record full wave propagation field over an area close to the weld. Then the effect of weld defect on the propagation field of Lamb waves was studied visually by watching an movie resulted from the recorded signals. This method was proved to be effective to detect the presence of hidden defect in the weld. Discrete wavelet transform(DWT) was applied to characterize the acquired ultrasonic signals and ideal band-pass filter was used to isolate wave components most sensitive to the weld defect. Different interactions with the weld defect were observed for different wave components. Thus this C-Scan method, combined with DWT and ideal band-pass filter, proved to be an effective methodology to experimentally study interactions of various laser excited Lamb Wave components with weld defect. In this work, the method was demonstrated by inspecting a hidden local incomplete penetration in weld. In fact, this method can be applied to study Lamb Wave interactions with any type of structural inconsistency. This work also proposed a ideal filtered based method to effectively reduce the total experimental time.

Ultrasonic Evaluation and Imaging

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

Crawford, Susan L.; Anderson, Michael T.; Diaz, Aaron A.

2015-10-01

Ultrasonic evaluation of materials for material characterization and flaw detection is as simple as manually moving a single-element probe across a speci-men and looking at an oscilloscope display in real time or as complex as automatically (under computer control) scanning a phased-array probe across a specimen and collecting encoded data for immediate or off-line data analyses. The reliability of the results in the second technique is greatly increased because of a higher density of measurements per scanned area and measurements that can be more precisely related to the specimen geometry. This chapter will briefly discuss applications of the collection ofmore » spatially encoded data and focus primarily on the off-line analyses in the form of data imaging. Pacific Northwest National Laboratory (PNNL) has been involved with as-sessing and advancing the reliability of inservice inspections of nuclear power plant components for over 35 years. Modern ultrasonic imaging techniques such as the synthetic aperture focusing technique (SAFT), phased-array (PA) technolo-gy and sound field mapping have undergone considerable improvements to effec-tively assess and better understand material constraints.« less

Inspection of additive manufactured parts using laser ultrasonics

NASA Astrophysics Data System (ADS)

Lévesque, D.; Bescond, C.; Lord, M.; Cao, X.; Wanjara, P.; Monchalin, J.-P.

2016-02-01

Additive manufacturing is a novel technology of high importance for global sustainability of resources. As additive manufacturing involves typically layer-by-layer fusion of the feedstock (wire or powder), an important characteristic of the fabricated metallic structural parts, such as those used in aero-engines, is the performance, which is highly related to the presence of defects, such as cracks, lack of fusion or bonding between layers, and porosity. For this purpose, laser ultrasonics is very attractive due to its non-contact nature and is especially suited for the analysis of parts of complex geometries. In addition, the technique is well adapted to online implementation and real-time measurement during the manufacturing process. The inspection can be performed from either the top deposited layer or the underside of the substrate and the defects can be visualized using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). In this work, a variety of results obtained off-line on INCONEL® 718 and Ti-6Al-4V coupons that were manufactured using laser powder, laser wire, or electron beam wire deposition are reported and most defects detected were further confirmed by X-ray micro-computed tomography.

ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM - 2011

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

West, B.; Waltz, R.

2012-06-21

Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2011 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report. The 2011 inspection program revealed that the structural integrity and waste confinement capability of the Savannah River Site waste tanks were maintained. All inspections scheduled per SRR-LWE-2011-00026, HLW Tank Farm Inspection Plan for 2011, were completed. Ultrasonic measurements (UT) performed in 2011 met the requirements of C-ESR-G-00006, In-Service Inspection Program for Highmore » Level Waste Tanks, Rev. 3, and WSRC-TR-2002-00061, Rev.6. UT inspections were performed on Tanks 25, 26 and 34 and the findings are documented in SRNL-STI-2011-00495, Tank Inspection NDE Results for Fiscal Year 2011, Waste Tanks 25, 26, 34 and 41. A total of 5813 photographs were made and 835 visual and video inspections were performed during 2011. A potential leaksite was discovered at Tank 4 during routine annual inspections performed in 2011. The new crack, which is above the allowable fill level, resulted in no release to the environment or tank annulus. The location of the crack is documented in C-ESR-G-00003, SRS High Level Waste Tank Leaksite Information, Rev.6.« less

Ultrasonic multi-skip tomography for pipe inspection

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

Volker, Arno; Zon, Tim van

The inspection of wall loss corrosion is difficult at pipe supports due to limited accessibility. The recently developed ultrasonic Multi-Skip screening technique is suitable for this problem. The method employs ultrasonic transducers in a pitch-catch geometry positioned on opposite sides of the pipe support. Shear waves are transmitted in the axial direction within the pipe wall, reflecting multiple times between the inner and outer surfaces before reaching the receivers. Along this path, the signals accumulate information on the integral wall thickness (e.g., via variations in travel time). The method is very sensitive in detecting the presence of wall loss, butmore » it is difficult to quantify both the extent and depth of the loss. Multi-skip tomography has been developed to reconstruct the wall thickness profile along the axial direction of the pipe. The method uses model-based full wave field inversion; this consists of a forward model for predicting the measured wave field and an iterative process that compares the predicted and measured wave fields and minimizes the differences with respect to the model parameters (i.e., the wall thickness profile). Experimental results are very encouraging. Various defects (slot and flat bottom hole) are reconstructed using the tomographic inversion. The general shape and width are well recovered. The current sizing accuracy is in the order of 1 mm.« less

Acousto-ultrasonic system for the inspection of composite armored vehicles

NASA Astrophysics Data System (ADS)

Godinez, Valery F.; Carlos, Mark F.; Delamere, Michael; Hoch, William; Fotopoulos, Christos; Dai, Weiming; Raju, Basavaraju B.

2001-04-01

In this paper the design and implementation of a unique acousto-ultrasonics system for the inspection of composite armored vehicles is discussed. The system includes a multi-sensor probe with a position-tracking device mounted on a computer controlled scanning bridge. The system also includes an arbitrary waveform generator with a multiplexer and a multi-channel acoustic emission board capable of simultaneously collecting and processing up to four acoustic signals in real time. C-scans of an armored vehicle panel with defects are presented.

Hybrid ray-FDTD model for the simulation of the ultrasonic inspection of CFRP parts

NASA Astrophysics Data System (ADS)

Jezzine, Karim; Ségur, Damien; Ecault, Romain; Dominguez, Nicolas; Calmon, Pierre

2017-02-01

Carbon Fiber Reinforced Polymers (CFRP) are commonly used in structural parts in the aeronautic industry, to reduce the weight of aircraft while maintaining high mechanical performances. Simulation of the ultrasonic inspections of these parts has to face the highly heterogeneous and anisotropic characteristics of these materials. To model the propagation of ultrasound in these composite structures, we propose two complementary approaches. The first one is based on a ray model predicting the propagation of the ultrasound in an anisotropic effective medium obtained from a homogenization of the material. The ray model is designed to deal with possibly curved parts and subsequent continuously varying anisotropic orientations. The second approach is based on the coupling of the ray model, and a finite difference scheme in time domain (FDTD). The ray model handles the ultrasonic propagation between the transducer and the FDTD computation zone that surrounds the composite part. In this way, the computational efficiency is preserved and the ultrasound scattering by the composite structure can be predicted. Inspections of flat or curved composite panels, as well as stiffeners can be performed. The models have been implemented in the CIVA software platform and compared to experiments. We also present an application of the simulation to the performance demonstration of the adaptive inspection technique SAUL (Surface Adaptive Ultrasound).

ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM 2010

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

West, B.; Waltz, R.

Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2010 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report. The 2010 inspection program revealed that the structural integrity and waste confinement capability of the Savannah River Site waste tanks were maintained. All inspections scheduled per SRR-LWE-2009-00138, HLW Tank Farm Inspection Plan for 2010, were completed. Ultrasonic measurements (UT) performed in 2010 met the requirements of C-ESG-00006, In-Service Inspection Program for Highmore » Level Waste Tanks, Rev. 3, and WSRC-TR-2002-00061, Rev.6. UT inspections were performed on Tanks 30, 31 and 32 and the findings are documented in SRNL-STI-2010-00533, Tank Inspection NDE Results for Fiscal Year 2010, Waste Tanks 30, 31 and 32. A total of 5824 photographs were made and 1087 visual and video inspections were performed during 2010. Ten new leaksites at Tank 5 were identified in 2010. The locations of these leaksites are documented in C-ESR-G-00003, SRS High Level Waste Tank Leaksite Information, Rev.5. Ten leaksites at Tank 5 were documented during tank wall/annulus cleaning activities. None of these new leaksites resulted in a release to the environment. The leaksites were documented during wall cleaning activities and the waste nodules associated with the leaksites were washed away. Previously documented leaksites were reactivated at Tank 12 during waste removal activities.« less

The Use of In-Service Inspection Data in the Performance Measurement of Non-Destructive Inspections (Mise en oeuvre de donn es resultant de visites d’inspection en service pour l’evaluation des performances des visites d’inspection non destructives)

DTIC Science & Technology

2005-03-01

Significant numbers of in-service inspections are occurring but at present, there is no organized process whereby these data are collected and...Reliability under Field Conditions” was held in Brussels in May 1998. The processes under which this data could be collected must be defined and...Requirement 2-3 2.3 Impact on Existing Certification Issues 2-5 2.4 Risk Assessment and POD 2-5 Chapter 3 – Data Collection Process 3-1 3.1

Model-based software for simulating ultrasonic pulse/echo inspections of metal components

NASA Astrophysics Data System (ADS)

Chiou, Chien-Ping; Margetan, Frank J.; Taylor, Jared L.; McKillip, Matthew; Engle, Brady J.; Roberts, Ronald A.; Barnard, Daniel J.

2017-02-01

Under the sponsorship of the National Science Foundation's Industry/University Cooperative Research Center at Iowa State University, an effort was initiated in 2015 to repackage existing research-grade software into user friendly tools for the rapid estimation of signal-to-noise ratio (S/N) for ultrasonic inspections of metals. The software combines: (1) a Python-based graphical user interface for specifying an inspection scenario and displaying results; and (2) a Fortran-based engine for computing defect signals and backscattered grain noise characteristics. The later makes use the Thompson-Gray Model for the response from an internal defect and the Independent Scatterer Model for backscattered grain noise. This paper provides an overview of the ongoing modeling effort with emphasis on recent developments. These include: treatment of angle-beam inspections, implementation of distance-amplitude corrections, changes in the generation of "invented" calibration signals, efforts to simulate ultrasonic C-scans; and experimental testing of model predictions. The simulation software can now treat both normal and oblique-incidence immersion inspections of curved metal components having equiaxed microstructures in which the grain size varies with depth. Both longitudinal and shear-wave inspections are treated. The model transducer can either be planar, spherically-focused, or bi-cylindrically-focused. A calibration (or reference) signal is required and is used to deduce the measurement system efficiency function. This can be "invented" by the software using center frequency and bandwidth information specified by the user, or, alternatively, a measured calibration signal can be used. Defect types include flat-bottomed-hole reference reflectors, and spherical pores and inclusions. Simulation outputs include estimated defect signal amplitudes, root-mean-squared grain noise amplitudes, and S/N as functions of the depth of the defect within the metal component. At any particular

Portable wireless ultrasonic systems for remote inspection

NASA Astrophysics Data System (ADS)

Zhong, C. H.; Croxford, A. J.; Wilcox, P. D.

2015-03-01

The weight and power storage of conventional wire and active wireless systems limit their applications to composite structures such as wind turbines and aerospace structures. In this paper, a structurally-integrated, inert, wireless guided wave system for rapid composite inspection is demonstrated. The wireless interface is based on electromagnetic coupling between three coils, one of which is physically connected to an ultrasonic piezoelectric transducer and embedded in the structure, while the other two are in a separate probing unit. Compact encapsulated sensor units are designed, built and successfully embedded into carbon fibre composite panel at manufacture. Chirp-based excitation is used to enable single-shot measurements with high signal-to-noise ratios to be obtained. Results from sensors embedded in carbon fibre reinforced composite panel show that signal amplitude obtained by embedding the sensor into composite is almost twice that of a surface-bonded sensor. The promising results indicate that the developed sensor can be potentially used for impact damage in a large composite structure.

An intelligent stand-alone ultrasonic device for monitoring local structural damage: implementation and preliminary experiments

NASA Astrophysics Data System (ADS)

Pertsch, Alexander; Kim, Jin-Yeon; Wang, Yang; Jacobs, Laurence J.

2011-01-01

Continuous structural health monitoring has the potential to significantly improve the safety management of aged, in-service civil structures. In particular, monitoring of local damage growth at hot-spot areas can help to prevent disastrous structural failures. Although ultrasonic nondestructive evaluation (NDE) has proved to be effective in monitoring local damage growth, conventional equipment and devices are usually bulky and only suitable for scheduled human inspections. The objective of this research is to harness the latest developments in embedded hardware and wireless communication for developing a stand-alone, compact ultrasonic device. The device is directed at the continuous structural health monitoring of civil structures. Relying on battery power, the device possesses the functionalities of high-speed actuation, sensing, signal processing, and wireless communication. Integrated with contact ultrasonic transducers, the device can generate 1 MHz Rayleigh surface waves in a steel specimen and measure response waves. An envelope detection algorithm based on the Hilbert transform is presented for efficiently determining the peak values of the response signals, from which small surface cracks are successfully identified.

Study on the ultrasonic inspection method using the full matrix capture for the in service railway wheel

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

Peng, Jianping; Wang, Li; Zhang, Yu

The quality of wheel is especially important for the safety of high speed railway. In this paper, a new ultrasonic array inspection method, the Full Matrix Capture (FMC) has been studied and applied to the high speed railway wheel inspection, especially in the wheel web from the tread. Firstly, the principle of FMC and TFM algorithm is discussed, and then the new optimization is applied to the standard FMC; Secondly the fundamentals of optimization is described in detail and the performance is analyzed. Finally, the experiment has been built with a standard phased array block and railway wheel, and thenmore » the testing results are discussed and analyzed. It is demonstrated that this change for the ultrasonic data acquisition and image reconstruction has higher efficiency and lower cost comparing to the FMC's procedure.« less

UCSD/FRA non-contact ultrasonic guided-wave system for rail inspection: an update

NASA Astrophysics Data System (ADS)

Coccia, Stefano; Phillips, Robert; Nucera, Claudio; Bartoli, Ivan; Salamone, Salvatore; Lanza di Scalea, Francesco; Fateh, Mahmood; Carr, Gary

2011-04-01

The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is developing a system for high-speed and non-contact rail defect detection. A prototype has been designed and field tested with the support of Volpe National Transportation Systems Center and ENSCO, Inc. The goal of this project is to develop a rail defect detection system that provides (a) better defect detection reliability (including internal transverse head defects under shelling and vertical split head defects), and (b) higher inspection speed than achievable by current rail inspection systems. This effort is also in direct response to Safety Recommendations issued by the National Transportation Safety Board (NTSB) following the disastrous train derailments at Superior, WI in 1992 and Oneida, NY in 2007 among others. The UCSD prototype uses non-contact ultrasonic probing of the rail head (laser and air-coupled), ultrasonic guided waves, and a proprietary real-time statistical analysis algorithm that maximizes the sensitivity to defects while minimizing false positives. The current design allows potential inspection speeds up to 40 mph, although all field tests have been conducted up to 15 mph so far. This paper summarizes (a) the latest technology development test conducted at the rail defect farm of Herzog, Inc. in St Joseph, MO in June 2010, and (b) the completion of the new Rail Defect Farm facility at the UCSD Camp Elliott Field Station with partial in-kind donations from the Burlington Northern Santa Fe (BNSF) Railway.

Wire Crimp Connectors Verification using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2007-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp connections is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp connector and wire is shown to correlate with the results of a destructive pull test, which previously has been used to assess crimp wire junction quality. Various crimp junction pathologies (missing wire strands, incorrect wire gauge, incomplete wire insertion in connector) are ultrasonically tested, and their results are correlated with pull tests. Results show that the ultrasonic measurement technique consistently (as evidenced with pull-testing data) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying the technique while wire crimps are installed is also presented.

The Influence of Inspection Angle, Wave Type and Beam Shape on Signal-to-Noise Ratios in Ultrasonic Pitch-Catch Inspections

NASA Astrophysics Data System (ADS)

Margetan, F. J.; Li, Anxiang; Thompson, R. B.

2007-03-01

Grain noise, which arises from the scattering of sound waves by microstructure, can limit the detection of small internal defects in metal components. Signal-to-noise (S/N) ratios for ultrasonic pitch/catch inspections are primarily determined by three factors: the scattering ability of the defect; the inherent noisiness of the microstructure (per unit volume); and finite-beam effects. An approximate single-scattering model has been formulated which contains terms representing each of these factors. In this paper the model is applied to a representative pitch/catch inspection problem, namely, the detection of a circular crack in a nickel cylinder. The object is to estimate S/N ratios for various choices of the inspection angle and sonic wave types, and to demonstrate how S/N is determined by the interplay of the defect, microstructure, and finite-beam factors. We also explore how S/N is influenced by the sizes, shapes, and orientations of the transmitter and receiver sound beams.

Ultrasonic Inspection to Quantify Failure Pathologies of Crimped Electrical Connections

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2014-01-01

Previous work has shown that ultrasonic inspection provides a means of assessing electrical crimp quality that ensures the electrical and mechanical integrity of an initial crimp before the installation process is completed. The amplitude change of a compressional ultrasonic wave propagating at right angles to the wire axis and through the junction of a crimp termination was shown to correlate with the results of destructive pull tests, which is a standard for assessing crimp wire junction quality. Of additional concern are crimps made at high speed assembly lines for wiring harnesses, which are used for critical applications, such as in aircraft. During high-speed assembly it is possible that many faulty crimps go undetected until long after assembly, and fail in service. The position and speed of the crimping jaw become factors as the high-speed crimp is formed. The work presented in this paper is designed to cover the more difficult and more subtle area of high-speed crimps by taking into account the rate change of the measurements. Building on the previous work, we present an analysis methodology, based on transmitted ultrasonic energy and timing of the first received pulse that is shown to correlate to the gauge of the crimp/ferrule combination and the position of the crimping jaw. Results demonstrating the detectability of a number of the crimp failure pathologies, such as missing strands, partially inserted wires and incomplete crimp compression, are presented. The ability of this technique to estimate crimp height, a mechanical measure of crimp quality, is discussed.

Ultrasonic inspection to quantify failure pathologies of crimped electrical connections

NASA Astrophysics Data System (ADS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2015-03-01

Previous work has shown that ultrasonic inspection provides a means of assessing electrical crimp quality that ensures the electrical and mechanical integrity of an initial crimp before the installation process is completed. The amplitude change of a compressional ultrasonic wave propagating at right angles to the wire axis and through the junction of a crimp termination was shown to correlate with the results of destructive pull tests, which is a standard for assessing crimp wire junction quality. Of additional concern are crimps made at high speed assembly lines for wiring harnesses, which are used for critical applications, such as in aircraft. During high-speed assembly it is possible that many faulty crimps go undetected until long after assembly, and fail in service. The position and speed of the crimping jaw become factors as the high-speed crimp is formed. The work presented in this paper is designed to cover the more difficult and more subtle area of high-speed crimps by taking into account the rate change of the measurements. Building on the previous work, we present an analysis methodology, based on transmitted ultrasonic energy and timing of the first received pulse that is shown to correlate to the gauge of the crimp/ferrule combination and the position of the crimping jaw. Results demonstrating the detectability of a number of the crimp failure pathologies, such as missing strands, partially inserted wires and incomplete crimp compression, are presented. The ability of this technique to estimate crimp height, a mechanical measure of crimp quality, is discussed.

Wire Crimp Termination Verification Using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Perey, Daniel F.; Cramer, K. Elliott; Yost, William T.

2007-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp terminations is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp termination and wire is shown to correlate with the results of a destructive pull test, which is a standard for assessing crimp wire junction quality. Various crimp junction pathologies such as undercrimping, missing wire strands, incomplete wire insertion, partial insulation removal, and incorrect wire gauge are ultrasonically tested, and their results are correlated with pull tests. Results show that the nondestructive ultrasonic measurement technique consistently (as evidenced with destructive testing) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying this technique while wire crimps are installed is also presented. The instrument is based on a two-jaw type crimp tool suitable for butt-splice type connections. Finally, an approach for application to multipin indenter type crimps will be discussed.

Engineering Task Plan for the Ultrasonic Inspection of Hanford Double Shell Tanks (DST) FY2000

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

JENSEN, C.E.

2000-01-10

This document facilitates the ultrasonic examination of Hanford double-shell tanks. Included are a plan for engineering activities (individual responsibilities), plan for performance demonstration testing, and a plan for field activities (tank inspection). Also included are a Statement of Work for contractor performance of the work and a protocol to be followed should tank flaws that exceed the acceptance criteria be discovered.

ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM 2009

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

West, B.; Waltz, R.

2010-06-21

Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2009 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report. The 2009 inspection program revealed that the structural integrity and waste confinement capability of the Savannah River Site waste tanks were maintained. All inspections scheduled per LWO-LWE-2008-00423, HLW Tank Farm Inspection Plan for 2009, were completed. All Ultrasonic measurements (UT) performed in 2009 met the requirements of C-ESG-00006, In-Service Inspection Program formore » High Level Waste Tanks, Rev. 1, and WSRC-TR-2002-00061, Rev.4. UT inspections were performed on Tank 29 and the findings are documented in SRNL-STI-2009-00559, Tank Inspection NDE Results for Fiscal Year 2009, Waste Tank 29. Post chemical cleaning UT measurements were made in Tank 6 and the results are documented in SRNL-STI-2009-00560, Tank Inspection NDE Results Tank 6, Including Summary of Waste Removal Support Activities in Tanks 5 and 6. A total of 6669 photographs were made and 1276 visual and video inspections were performed during 2009. Twenty-Two new leaksites were identified in 2009. The locations of these leaksites are documented in C-ESR-G-00003, SRS High Level Waste Tank Leaksite Information, Rev.4. Fifteen leaksites at Tank 5 were documented during tank wall/annulus cleaning activities. Five leaksites at Tank 6 were documented during tank wall/annulus cleaning activities. Two new leaksites were identified at Tank 19 during waste removal activities. Previously documented leaksites were reactivated at Tanks 5 and 12 during waste removal activities. Also, a very small amount of additional leakage from a previously identified leaksite at Tank 14 was observed.« less

Inspection of thick welded joints using laser-ultrasonic SAFT.

PubMed

Lévesque, D; Asaumi, Y; Lord, M; Bescond, C; Hatanaka, H; Tagami, M; Monchalin, J-P

2016-07-01

The detection of defects in thick butt joints in the early phase of multi-pass arc welding would be very valuable to reduce cost and time in the necessity of reworking. As a non-contact method, the laser-ultrasonic technique (LUT) has the potential for the automated inspection of welds, ultimately online during manufacturing. In this study, testing has been carried out using LUT combined with the synthetic aperture focusing technique (SAFT) on 25 and 50mm thick butt welded joints of steel both completed and partially welded. EDM slits of 2 or 3mm height were inserted at different depths in the multi-pass welding process to simulate a lack of fusion. Line scans transverse to the weld are performed with the generation and detection laser spots superimposed directly on the surface of the weld bead. A CCD line camera is used to simultaneously acquire the surface profile for correction in the SAFT processing. All artificial defects but also real defects are visualized in the investigated thick butt weld specimens, either completed or partially welded after a given number of passes. The results obtained clearly show the potential of using the LUT with SAFT for the automated inspection of arc welds or hybrid laser-arc welds during manufacturing. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Airborne ultrasonic inspection in carbon/carbon composite materials

NASA Astrophysics Data System (ADS)

Yang, In-Young; Kim, Young-Hun; Park, Je-Woong; Hsu, David K.; Song, Song-Jin; Cho, Hyun-Jun; Kim, Sun-Kyu; Im, Kwang-Hee

2007-07-01

In this work, a carbon/carbon (C/C) composite material was nondestructively characterized with non-contact ultrasonic methods using automated acquisition scanner as well as contact ultrasonic measurement because (C/C) composite materials have obvious high price over conventional materials. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake was measured and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the motorized system with using dry-coupling ultrasonics and through transmission method in immersion. Finally, results using a proposed peak-delay measurement method well corresponded to ultrasonic velocities of the pulse overlap method.

Development of Ultrasonic and Fabry-Perot Interferometer for Non-Destruction Inspection of Aging Aircraft

NASA Technical Reports Server (NTRS)

Smith, Alphonso C.

1998-01-01

Fabry-Perot Interferometer (FPI) sensor detection system was continued and refined modifications were made in the data acquisition and evaluation process during the last year. The ultrasonic and FPI detection system was improved from one to multiple sensor detectors. Physical models were developed to understand the physical phenomenon of this work. Multilayered flawed samples were fabricated for inspection by a prototype ultrasonic and FPI detection. Experimental data was verified with simulated results. Undergraduate students that were associated with this research gained valuable knowledge from this experience. This was a learning process helping students to understand the importance of research and its application to solve important technological problems. As a result of our students exposure to this research two and planning to continue this type of research work in graduate school. A prototype instrument package was laboratory tested an actual airframe structure for documentation purposes.

Characterization of Stress Corrosion Cracking Using Laser Ultrasonics

DOT National Transportation Integrated Search

2008-08-31

In-service inspection of gas and oil pipelines is a subject of great current interest. Issues of safety and fitness for service have driven extensive efforts to develop effective monitoring and inspection techniques. A number of effective NDT techniq...

Flexible integration of robotics, ultrasonics and metrology for the inspection of aerospace components

NASA Astrophysics Data System (ADS)

Mineo, Carmelo; MacLeod, Charles; Morozov, Maxim; Pierce, S. Gareth; Summan, Rahul; Rodden, Tony; Kahani, Danial; Powell, Jonathan; McCubbin, Paul; McCubbin, Coreen; Munro, Gavin; Paton, Scott; Watson, David

2017-02-01

Improvements in performance of modern robotic manipulators have in recent years allowed research aimed at development of fast automated non-destructive testing (NDT) of complex geometries. Contemporary robots are well adaptable to new tasks. Several robotic inspection prototype systems and a number of commercial products have been developed worldwide. This paper describes the latest progress in research focused at large composite aerospace components. A multi-robot flexible inspection cell is used to take the fundamental research and the feasibility studies to higher technology readiness levels, all set for the future industrial exploitation. The robot cell is equipped with high accuracy and high payload robots, mounted on 7 meter tracks, and an external rotary axis. A robotically delivered photogrammetry technique is first used to assess the position of the components placed within the robot working envelope and their deviation to CAD. Offline programming is used to generate a scan path for phased array ultrasonic testing (PAUT). PAUT is performed using a conformable wheel probe, with high data rate acquisition from PAUT controller. Real-time robot path-correction, based on force-torque control (FTC), is deployed to achieve the optimum ultrasonic coupling and repeatable data quality. New communication software is developed that enabled simultaneous control of the multiple robots performing different tasks and the acquisition of accurate positional data. All aspects of the system are controlled through a purposely developed graphic user interface that enables the flexible use of the unique set of hardware resources, the data acquisition, visualization and analysis.

Simulation and experiment for the inspection of stainless steel bolts in servicing using an ultrasonic phased array

NASA Astrophysics Data System (ADS)

Chen, Jinzhong; He, Renyang; Kang, Xiaowei; Yang, Xuyun

2015-10-01

The non-destructive testing of small-sized (M12-M20) stainless steel bolts in servicing is always a technical problem. This article focuses on the simulation and experimental research of stainless steel bolts with an artificial defect reflector using ultrasonic phased array inspection. Based on the observation of the sound field distribution of stainless steel bolts in ultrasonic phased array as well as simulation modelling and analysis of the phased array probes' detection effects with various defect sizes, different artificial defect reflectors of M16 stainless steel bolts are machined in reference to the simulation results. Next, those bolts are tested using a 10-wafer phased array probe with 5 MHz. The test results finally prove that ultrasonic phased array can detect 1-mm cracks in diameter with different depths of M16 stainless steel bolts and a metal loss of Φ1 mm of through-hole bolts, which provides technical support for future non-destructive testing of stainless steel bolts in servicing.

Progress on the development of automated data analysis algorithms and software for ultrasonic inspection of composites

NASA Astrophysics Data System (ADS)

Aldrin, John C.; Coughlin, Chris; Forsyth, David S.; Welter, John T.

2014-02-01

Progress is presented on the development and implementation of automated data analysis (ADA) software to address the burden in interpreting ultrasonic inspection data for large composite structures. The automated data analysis algorithm is presented in detail, which follows standard procedures for analyzing signals for time-of-flight indications and backwall amplitude dropout. ADA processing results are presented for test specimens that include inserted materials and discontinuities produced under poor manufacturing conditions.

Constant Group Velocity Ultrasonic Guided Wave Inspection for Corrosion and Erosion Monitoring in Pipes

NASA Astrophysics Data System (ADS)

Instanes, Geir; Pedersen, Audun; Toppe, Mads; Nagy, Peter B.

2009-03-01

This paper describes a novel ultrasonic guided wave inspection technique for the monitoring of internal corrosion and erosion in pipes, which exploits the fundamental flexural mode to measure the average wall thickness over the inspection path. The inspection frequency is chosen so that the group velocity of the fundamental flexural mode is essentially constant throughout the wall thickness range of interest, while the phase velocity is highly dispersive and changes in a systematic way with varying wall thickness in the pipe. Although this approach is somewhat less accurate than the often used transverse resonance methods, it smoothly integrates the wall thickness over the whole propagation length, therefore it is very robust and can tolerate large and uneven thickness variations from point to point. The constant group velocity (CGV) method is capable of monitoring the true average of the wall thickness over the inspection length with an accuracy of 1% even in the presence of one order of magnitude larger local variations. This method also eliminates spurious variations caused by changing temperature, which can cause fairly large velocity variations, but do not significantly influence the dispersion as measured by the true phase angle in the vicinity of the CGV point. The CGV guided wave CEM method was validated in both laboratory and field tests.

In-Line Ultrasonic Monitoring for Sediments Stuck on Inner Wall of a Polyvinyl Chloride Pipe

PubMed Central

2014-01-01

This research verified the applicability and effectiveness of the ultrasonic monitoring of sediments stuck on the inner wall of polyvinyl chloride (PVC) pipes. For identifying the transmittance of acoustic energy and the speed of sound in the PVC material, the pulse-echo ultrasonic testing was conducted for PVC sheets of different thicknesses. To simulate the solidified sediment, the hot melt adhesive (HMA) was covered on the inner wall of the PVC pipe in different heights. From the experiment, the speeds of sound in the PVC and the HMA materials were obtained as about 2258 and 2000 m/s, respectively. The thickness of the materials was calculated through the signal processing such as taking the absolute value and low pass filtering, the echo detection, and the measurement of the time of flight. The errors between actual and measured thicknesses of PVC sheets were below 5%. In the case of the substance stuck on the inner wall, the errors were below 2.5%. Since the pulse-echo ultrasonic inspection is available on the outer surface and its measurement accuracy was over 95%, it can be an efficient and effective in-service structural health monitoring for the sediment on the wall of PVC pipes. PMID:25243223

Design and Demonstration of Automated Data Analysis Algorithms for Ultrasonic Inspection of Complex Composite Panels with Bonds

DTIC Science & Technology

2016-02-01

certification process. INTRODUCTION The ultrasonic inspection of aerospace composites has been demonstrated to be one of the most effective methods to...normal part conditions. Anomalous indications studied in this program include inserted materials, porosity, ply ‘laps and gaps’, and wrinkles . Inserted...partially scanned inserts at the radii. Wrinkles , laps and gaps have also been included in the truth table, but detection rates for these flaws are

Evaluation of ultrasonic array imaging algorithms for inspection of a coarse grained material

NASA Astrophysics Data System (ADS)

Van Pamel, A.; Lowe, M. J. S.; Brett, C. R.

2014-02-01

Improving the ultrasound inspection capability for coarse grain metals remains of longstanding interest to industry and the NDE research community and is expected to become increasingly important for next generation power plants. A test sample of coarse grained Inconel 625 which is representative of future power plant components has been manufactured to test the detectability of different inspection techniques. Conventional ultrasonic A, B, and C-scans showed the sample to be extraordinarily difficult to inspect due to its scattering behaviour. However, in recent years, array probes and Full Matrix Capture (FMC) imaging algorithms, which extract the maximum amount of information possible, have unlocked exciting possibilities for improvements. This article proposes a robust methodology to evaluate the detection performance of imaging algorithms, applying this to three FMC imaging algorithms; Total Focusing Method (TFM), Phase Coherent Imaging (PCI), and Decomposition of the Time Reversal Operator with Multiple Scattering (DORT MSF). The methodology considers the statistics of detection, presenting the detection performance as Probability of Detection (POD) and probability of False Alarm (PFA). The data is captured in pulse-echo mode using 64 element array probes at centre frequencies of 1MHz and 5MHz. All three algorithms are shown to perform very similarly when comparing their flaw detection capabilities on this particular case.

Inspection Correlation Study of Ultrasonic-Based In Situ Structural Health Monitoring Monthly Report for December 2014-January 2015

DTIC Science & Technology

2015-05-01

fatigue an induced ultrasonic elastic vibration (via piezoelectric transducers [ PZTs ]) propagates through the dogbone specimen. A receiver PZT picks up...inspection of fatigue crack growth in aluminum 7075-T6 dogbone specimens. Acellent Technologies, Inc., is supporting this project through providing...January 2015. 15. SUBJECT TERMS structural health monitoring, probabilistics, fatigue damage, guided waves, Lamb waves 16. SECURITY CLASSIFICATION OF

Apparatus for the concurrent ultrasonic inspection of partially completed welds

DOEpatents

Johnson, John A.

2000-01-01

An apparatus for the concurrent nondestructive evaluation of partially completed welds is described and which is used in combination with an automated welder and which includes an ultrasonic signal generator mounted on the welder and which generates an ultrasonic signal which is directed toward one side of the partially completed welds; an ultrasonic signal receiver mounted on the automated welder for detecting ultrasonic signals which are transmitted by the ultrasonic signal generator and which are reflected or diffracted from one side of the partially completed weld or which passes through a given region of the partially completed weld; and an analysis assembly coupled with the ultrasonic signal receiver and which processes the ultrasonic signals received by the ultrasonic signal receiver to identify welding flaws in the partially completed weld.

Study on the Non-contact Acoustic Inspection Method for Concrete Structures by using Strong Ultrasonic Sound source

NASA Astrophysics Data System (ADS)

Sugimoto, Tsuneyoshi; Uechi, Itsuki; Sugimoto, Kazuko; Utagawa, Noriyuki; Katakura, Kageyoshi

Hammering test is widely used to inspect the defects in concrete structures. However, this method has a major difficulty in inspect at high-places, such as a tunnel ceiling or a bridge girder. Moreover, its detection accuracy is dependent on a tester's experience. Therefore, we study about the non-contact acoustic inspection method of the concrete structure using the air borne sound wave and a laser Doppler vibrometer. In this method, the concrete surface is excited by air-borne sound wave emitted with a long range acoustic device (LRAD), and the vibration velocity on the concrete surface is measured by a laser Doppler vibrometer. A defect part is detected by the same flexural resonance as the hammer method. It is already shown clearly that detection of a defect can be performed from a long distance of 5 m or more using a concrete test object. Moreover, it is shown that a real concrete structure can also be applied. However, when the conventional LRAD was used as a sound source, there were problems, such as restrictions of a measurement angle and the surrounding noise. In order to solve these problems, basic examination which used the strong ultrasonic wave sound source was carried out. In the experiment, the concrete test object which includes an imitation defect from 5-m distance was used. From the experimental result, when the ultrasonic sound source was used, restrictions of a measurement angle become less severe and it was shown that circumference noise also falls dramatically.

Electronic Inspection of Beef

NASA Technical Reports Server (NTRS)

Anselmo, Victor J.; Gammell, Paul M.; Clark, Jerry

1987-01-01

Two proposed methods for grading beef quality based on inspection by electronic equipment: one method uses television camera to generate image of a cut of beef as customer sees it; other uses ultrasonics to inspect live animal or unsliced carcasses. Both methods show promise for automated meat inspection.

Optimized planning of in-service inspections of local flow-accelerated corrosion of pipeline elements used in the secondary coolant circuit of the VVER-440-based units at the Novovoronezh NPP

NASA Astrophysics Data System (ADS)

Tomarov, G. V.; Povarov, V. P.; Shipkov, A. A.; Gromov, A. F.; Budanov, V. A.; Golubeva, T. N.

2015-03-01

Matters concerned with making efficient use of the information-analytical system on the flow-accelerated corrosion problem in setting up in-service examination of the metal of pipeline elements operating in the secondary coolant circuit of the VVER-440-based power units at the Novovoronezh NPP are considered. The principles used to select samples of pipeline elements in planning ultrasonic thickness measurements for timely revealing metal thinning due to flow-accelerated corrosion along with reducing the total amount of measurements in the condensate-feedwater path are discussed.

Qualification of the RSRM field joint CF case-to-insulation bondline inspection using the Thiokol Corporation ultrasonic RSRM bondline inspection system

NASA Technical Reports Server (NTRS)

Cook, M.

1990-01-01

Qualification testing of Combustion Engineering's AMDATA Intraspect/98 Data Acquisition and Imaging System that applies to the redesigned solid rocket motor field joint capture feature case-to-insulation bondline inspection was performed. Testing was performed at M-111, the Thiokol Corp. Inert Parts Preparation Building. The purpose of the inspection was to verify the integrity of the capture feature area case-to-insulation bondline. The capture feature scanner was calibrated over an intentional 1.0 to 1.0 in. case-to-insulation unbond. The capture feature scanner was then used to scan 60 deg of a capture feature field joint. Calibration of the capture feature scanner was then rechecked over the intentional unbond to ensure that the calibration settings did not change during the case scan. This procedure was successfully performed five times to qualify the unbond detection capability of the capture feature scanner. The capture feature scanner qualified in this test contains many points of mechanical instability that can affect the overall ultrasonic signal response. A new generation scanner, designated the sigma scanner, should be implemented to replace the current configuration scanner. The sigma scanner eliminates the unstable connection points of the current scanner and has additional inspection capabilities.

Sand/cement ratio evaluation on mortar using neural networks and ultrasonic transmission inspection.

PubMed

Molero, M; Segura, I; Izquierdo, M A G; Fuente, J V; Anaya, J J

2009-02-01

The quality and degradation state of building materials can be determined by nondestructive testing (NDT). These materials are composed of a cementitious matrix and particles or fragments of aggregates. Sand/cement ratio (s/c) provides the final material quality; however, the sand content can mask the matrix properties in a nondestructive measurement. Therefore, s/c ratio estimation is needed in nondestructive characterization of cementitious materials. In this study, a methodology to classify the sand content in mortar is presented. The methodology is based on ultrasonic transmission inspection, data reduction, and features extraction by principal components analysis (PCA), and neural network classification. This evaluation is carried out with several mortar samples, which were made while taking into account different cement types and s/c ratios. The estimated s/c ratio is determined by ultrasonic spectral attenuation with three different broadband transducers (0.5, 1, and 2 MHz). Statistical PCA to reduce the dimension of the captured traces has been applied. Feed-forward neural networks (NNs) are trained using principal components (PCs) and their outputs are used to display the estimated s/c ratios in false color images, showing the s/c ratio distribution of the mortar samples.

Ultrasonic Phased Array Simulations of Welded Components at NASA

NASA Technical Reports Server (NTRS)

Roth, D. J.; Tokars, R. P.; Martin, R. E.; Rauser, R. W.; Aldrin, J. C.

2009-01-01

Comprehensive and accurate inspections of welded components have become of increasing importance as NASA develops new hardware such as Ares rocket segments for future exploration missions. Simulation and modeling will play an increasing role in the future for nondestructive evaluation in order to better understand the physics of the inspection process, to prove or disprove the feasibility for an inspection method or inspection scenario, for inspection optimization, for better understanding of experimental results, and for assessment of probability of detection. This study presents simulation and experimental results for an ultrasonic phased array inspection of a critical welded structure important for NASA future exploration vehicles. Keywords: nondestructive evaluation, computational simulation, ultrasonics, weld, modeling, phased array

Generic system components of the Thiokol ultrasonic RSRM case-to-insulation bondline inspection system

NASA Technical Reports Server (NTRS)

Cook, M.

1989-01-01

Qualification testing of the Ultrasonic Redesigned Solid Rocket Motor Bondline Inspection Systems (URBIS) was conducted at the Thiokol Nondestructive Evaluation Test Facility M337A and at the Rotation Process Storage Facility at Kennedy Space Center. The test was performed on portions of the URBIS that are generic to redesigned solid rocket motor case-to-insulation bondline inspections. Testing began on Feb. 13, 1989 and was completed on May 26, 1989. The main purpose of the test was to verify that each URBIS performed to the manufacturer's specifications in the same manner and to make any procedural changes necessary for specific redesigned solid rocket motor inspections. All five URBISs passed every stage of the qualification test. Each URBIS is now qualified for use on redesigned solid rocket motors. Verifying the fact that each URBIS obtains and analyzes data in a similar fashion has eliminated concerns about variations in data between the five systems. The following recommendations were made as a result of this test: (1) each URBIS should be located within a stable environment; (2) an electronic preventative maintenance program should be established for each URBIS; (3) when the URBIS is being utilized to perform transducer analysis, the URBIS equipment setting should match the equipment setting noted on the manufacturer-supplied transducer certification sheet; and (4) optimum scan velocities for each inspection technique (clevis, capture feature, pinhole and membrane) should be determined through further testing.

Model benchmarking and reference signals for angled-beam shear wave ultrasonic nondestructive evaluation (NDE) inspections

NASA Astrophysics Data System (ADS)

Aldrin, John C.; Hopkins, Deborah; Datuin, Marvin; Warchol, Mark; Warchol, Lyudmila; Forsyth, David S.; Buynak, Charlie; Lindgren, Eric A.

2017-02-01

For model benchmark studies, the accuracy of the model is typically evaluated based on the change in response relative to a selected reference signal. The use of a side drilled hole (SDH) in a plate was investigated as a reference signal for angled beam shear wave inspection for aircraft structure inspections of fastener sites. Systematic studies were performed with varying SDH depth and size, and varying the ultrasonic probe frequency, focal depth, and probe height. Increased error was observed with the simulation of angled shear wave beams in the near-field. Even more significant, asymmetry in real probes and the inherent sensitivity of signals in the near-field to subtle test conditions were found to provide a greater challenge with achieving model agreement. To achieve quality model benchmark results for this problem, it is critical to carefully align the probe with the part geometry, to verify symmetry in probe response, and ideally avoid using reference signals from the near-field response. Suggested reference signals for angled beam shear wave inspections include using the `through hole' corner specular reflection signal and the full skip' signal off of the far wall from the side drilled hole.

Ultrasonic, microwave, and millimeter wave inspection techniques for adhesively bonded stacked open honeycomb core composites

NASA Astrophysics Data System (ADS)

Thomson, Clint D.; Cox, Ian; Ghasr, Mohammad Tayeb Ahmed; Ying, Kuang P.; Zoughi, Reza

2015-03-01

Honeycomb sandwich composites are used extensively in the aerospace industry to provide stiffness and thickness to lightweight structures. A common fabrication method for thick, curved sandwich structures is to stack and bond multiple honeycomb layers prior to machining core curvatures. Once bonded, each adhesive layer must be inspected for delaminations and the presence of unwanted foreign materials. From a manufacturing and cost standpoint, it can be advantageous to inspect the open core prior to face sheet closeout in order to reduce end-article scrap rates. However, by nature, these honeycomb sandwich composite structures are primarily manufactured from low permittivity and low loss materials making detection of delamination and some of the foreign materials (which also are low permittivity and low loss) quite challenging in the microwave and millimeter wave regime. Likewise, foreign materials such as release film in adhesive layers can be sufficiently thin as to not cause significant attenuation in through-transmission ultrasonic signals, making them difficult to detect. This paper presents a collaborative effort intended to explore the efficacy of different non-contact NDI techniques for detecting flaws in a stacked open fiberglass honeycomb core panel. These techniques primarily included air-coupled through-transmission ultrasonics, single-sided wideband synthetic aperture microwave and millimeter-wave imaging, and lens-focused technique. The goal of this investigation has been to not only evaluate the efficacy of these techniques, but also to determine their unique advantages and limitations for evaluating parameters such as flaw type, flaw size, and flaw depth.

Determination of Flaw Type and Location Using an Expert Module in Ultrasonic Nondestructive Testing for Weld Inspection

NASA Astrophysics Data System (ADS)

Shahriari, D.; Zolfaghari, A.; Masoumi, F.

2011-01-01

Nondestructive evaluation is explained as nondestructive testing, nondestructive inspection, and nondestructive examination. It is a desire to determine some characteristic of the object or to determine whether the object contains irregularities, discontinuities, or flaws. Ultrasound based inspection techniques are used extensively throughout industry for detection of flaws in engineering materials. The range and variety of imperfections encountered is large, and critical assessment of location, size, orientation and type is often difficult. In addition, increasing quality requirements of new standards and codes of practice relating to fitness for purpose are placing higher demands on operators. Applying of an expert knowledge-based analysis in ultrasonic examination is a powerful tool that can help assure safety, quality, and reliability; increase productivity; decrease liability; and save money. In this research, an expert module system is coupled with ultrasonic examination (A-Scan Procedure) to determine and evaluate type and location of flaws that embedded during welding parts. The processing module of this expert system is implemented based on EN standard to classify welding defects, acceptance condition and measuring of their location via echo static pattern and image processing. The designed module introduces new system that can automate evaluating of the results of A-scan method according to EN standard. It can simultaneously recognize the number and type of defects, and determine flaw position during each scan.

Wavelet analysis of poorly-focused ultrasonic signal of pressure tube inspection in nuclear industry

NASA Astrophysics Data System (ADS)

Zhao, Huan; Gachagan, Anthony; Dobie, Gordon; Lardner, Timothy

2018-04-01

Pressure tube fabrication and installment challenges combined with natural sagging over time can produce issues with probe alignment for pressure tube inspection of the primary circuit of CANDU reactors. The ability to extract accurate defect depth information from poorly focused ultrasonic signals would reduce additional inspection procedures, which leads to a significant time and cost saving. Currently, the defect depth measurement protocol is to simply calculate the time difference between the peaks of the echo signals from the tube surface and the defect from a single element probe focused at the back-wall depth. When alignment issues are present, incorrect focusing results in interference within the returning echo signal. This paper proposes a novel wavelet analysis method that employs the Haar wavelet to decompose the original poorly focused A-scan signal and reconstruct detailed information based on a selected high frequency component range within the bandwidth of the transducer. Compared to the original signal, the wavelet analysis method provides additional characteristic defect information and an improved estimate of defect depth with errors less than 5%.

Polymer subtrates for dry-coupled ultrasonic transducers

NASA Astrophysics Data System (ADS)

Komsky, Igor N.

2003-07-01

Dry-coupled inspection techniques are very important for applications on components with non-uniform surfaces and for inspections of advanced materials or coatings that are porous or otherwise sensitive to the application of water, gel, or some other ultrasonic couplants. To overcome the problems associated with the liquid coupling medium, a number of polymer films have been developed to transmit the ultrasound through a dry interface. These materials are very flexible so even low pressure loading is sufficient to adapt the films to the irregular inspection surfaces. Several polymer films have been evaluated to develop dry-coupled substrates for transducer modules. The modules will be utilized to detect and characterize fatigue cracks and corrosion spots in the aircraft structures. Ultrasonic properties of the polymer films were measured and compared with the properties of plastic or rubber-like materials commonly used for ultrasonic applications. Experiments have been carried out to analyze propagation of longitudinal and shear waves in the films. Two different types of the ultrasonic modules with the flexible polymer substrates are being developed. The influence of the surface condition on the module performance was evaluated for both types of the modules.

Baseline UT Measurements for Armor Inspection

NASA Astrophysics Data System (ADS)

Margetan, Frank J.; Richter, Nate; Barnard, Dan; Hsu, David; Gray, Tim; Brasche, Lisa; Bruce Thompson, R.

2010-02-01

Some prototype armor panels are fabricated from several layers of dissimilar material bonded together. These may include ceramics, graphite composites, fiberglass composites and rubber. The ultrasonic properties of these layers influence inspections for armor defects. In this paper we describe measurements of ultrasonic velocity, attenuation, sound beam distortion and signal fluctuations for the individual layers comprising one armor prototype. We then discuss how knowledge of these properties can be used when choosing an optimum frequency for an ultrasonic pitch/catch immersion inspection. In our case an effective inspection frequency near 1.5 MHz affords: (1) adequate strength of through-transmitted signals in unflawed armor; (2) adequate lateral resolution for detecting small disbonds at interfaces; and (3) low levels of UT signal fluctuations due to the natural inhomogeneity of certain armor layers. The utility of this approach is demonstrated using armor panels containing artificial disbonds at selected interfaces.

Inspection apparatus for evaluating a partially completed weld

DOEpatents

Smartt, Herschel B.; Larsen, Eric D.; Johnson, Jonn A.

2001-01-01

An inspection apparatus for evaluating a partially completed weld is described and which is utilized in combination with an automated movable welder which moves across a supporting surface, and wherein the inspection apparatus includes a coupling member mounted on the welder; a frame member mounted on the coupling member; an ultrasonic sensor mounted on the frame member and disposed in ultrasonic sound transmitting relation relative to the partially completed weld; and a drive assembly for adjusting the position of the ultrasonic sensor relative to the partially completed weld.

Potential advantages associated with implementing a risk-based inspection program by a nuclear facility

NASA Astrophysics Data System (ADS)

McNeill, Alexander, III; Balkey, Kenneth R.

1995-05-01

The current inservice inspection activities at a U.S. nuclear facility are based upon the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI. The Code selects examination locations based upon a sampling criteria which includes component geometry, stress, and usage among other criteria. This can result in a significant number of required examinations. As a result of regulatory action each nuclear facility has conducted probabilistic risk assessments (PRA) or individual plant examinations (IPE), producing plant specific risk-based information. Several initiatives have been introduced to apply this new plant risk information. Among these initiatives is risk-based inservice inspection. A code case has been introduced for piping inspections based upon this new risk- based technology. This effort brought forward to the ASME Section XI Code committee, has been initiated and championed by the ASME Research Task Force on Risk-Based Inspection Guidelines -- LWR Nuclear Power Plant Application. Preliminary assessments associated with the code case have revealed that potential advantages exist in a risk-based inservice inspection program with regard to a number of exams, risk, personnel exposure, and cost.

Inspection of Nuclear Power Plant Containment Structures

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

Graves, H.L.; Naus, D.J.; Norris, W.E.

1998-12-01

Safety-related nuclear power plant (NPP) structures are designed to withstand loadings from a number of low-probability external and interval events, such as earthquakes, tornadoes, and loss-of-coolant accidents. Loadings incurred during normal plant operation therefore generally are not significant enough to cause appreciable degradation. However, these structures are susceptible to aging by various processes depending on the operating environment and service conditions. The effects of these processes may accumulate within these structures over time to cause failure under design conditions, or lead to costly repair. In the late 1980s and early 1990s several occurrences of degradation of NPP structures were discoveredmore » at various facilities (e.g., corrosion of pressure boundary components, freeze- thaw damage of concrete, and larger than anticipated loss of prestressing force). Despite these degradation occurrences and a trend for an increasing rate of occurrence, in-service inspection of the safety-related structures continued to be performed in a somewhat cursory manner. Starting in 1991, the U.S. Nuclear Regulatory Commission (USNRC) published the first of several new requirements to help ensure that adequate in-service inspection of these structures is performed. Current regulatory in-service inspection requirements are reviewed and a summary of degradation experience presented. Nondestructive examination techniques commonly used to inspect the NPP steel and concrete structures to identify and quantify the amount of damage present are reviewed. Finally, areas where nondestructive evaluation techniques require development (i.e., inaccessible portions of the containment pressure boundary, and thick heavily reinforced concrete sections are discussed.« less

Modeling approaches for the simulation of ultrasonic inspections of anisotropic composite structures in the CIVA software platform

NASA Astrophysics Data System (ADS)

Jezzine, Karim; Imperiale, Alexandre; Demaldent, Edouard; Le Bourdais, Florian; Calmon, Pierre; Dominguez, Nicolas

2018-04-01

Models for the simulation of ultrasonic inspections of flat and curved plate-like composite structures, as well as stiffeners, are available in the CIVA-COMPOSITE module released in 2016. A first modelling approach using a ray-based model is able to predict the ultrasonic propagation in an anisotropic effective medium obtained after having homogenized the composite laminate. Fast 3D computations can be performed on configurations featuring delaminations, flat bottom holes or inclusions for example. In addition, computations on ply waviness using this model will be available in CIVA 2017. Another approach is proposed in the CIVA-COMPOSITE module. It is based on the coupling of CIVA ray-based model and a finite difference scheme in time domain (FDTD) developed by AIRBUS. The ray model handles the ultrasonic propagation between the transducer and the FDTD computation zone that surrounds the composite part. In this way, the computational efficiency is preserved and the ultrasound scattering by the composite structure can be predicted. Alternatively, a high order finite element approach is currently developed at CEA but not yet integrated in CIVA. The advantages of this approach will be discussed and first simulation results on Carbon Fiber Reinforced Polymers (CFRP) will be shown. Finally, the application of these modelling tools to the construction of metamodels is discussed.

Experimental investigation by laser ultrasonics for high speed train axle diagnostics.

PubMed

Cavuto, A; Martarelli, M; Pandarese, G; Revel, G M; Tomasini, E P

2015-01-01

The present paper demonstrates the applicability of a laser-ultrasonic procedure to improve the performances of train axle ultrasonic inspection. The method exploits an air-coupled ultrasonic probe that detects the ultrasonic waves generated by a high-power pulsed laser. As a result, the measurement chain is completely non-contact, from generation to detection, this making it possible to considerably speed up inspection time and make the set-up more flexible. The main advantage of the technique developed is that it works in thermo-elastic regime and it therefore can be considered as a non-destructive method. The laser-ultrasonic procedure investigated has been applied for the inspection of a real high speed train axle provided by the Italian railway company (Trenitalia), on which typical fatigue defects have been expressly created according to standard specifications. A dedicated test bench has been developed so as to rotate the axle with the angle control and to speed up the inspection of the axle surface. The laser-ultrasonic procedure proposed can be automated and is potentially suitable for regular inspection of train axles. The main achievements of the activity described in this paper are: – the study of the effective applicability of laser-ultrasonics for the diagnostic of train hollow axles with variable sections by means of a numerical FE model, – the carrying out of an automated experiment on a real train axle, – the analysis of the sensitivity to experimental parameters, like laser source – receiving probe distance and receiving probe angular position, – the demonstration that the technique is suitable for the detection of surface defects purposely created on the train axle. Copyright © 2014 Elsevier B.V. All rights reserved.

Quantitative ultrasonic testing of acoustically anisotropic materials with verification on austenitic and dissimilar weld joints

NASA Astrophysics Data System (ADS)

Boller, C.; Pudovikov, S.; Bulavinov, A.

2012-05-01

Austenitic stainless steel materials are widely used in a variety of industry sectors. In particular, the material is qualified to meet the design criteria of high quality in safety related applications. For example, the primary loop of the most of the nuclear power plants in the world, due to high durability and corrosion resistance, is made of this material. Certain operating conditions may cause a range of changes in the integrity of the component, and therefore require nondestructive testing at reasonable intervals. These in-service inspections are often performed using ultrasonic techniques, in particular when cracking is of specific concern. However, the coarse, dendritic grain structure of the weld material, formed during the welding process, is extreme and unpredictably anisotropic. Such structure is no longer direction-independent to the ultrasonic wave propagation; therefore, the ultrasonic beam deflects and redirects and the wave front becomes distorted. Thus, the use of conventional ultrasonic testing techniques using fixed beam angles is very limited and the application of ultrasonic Phased Array techniques becomes desirable. The "Sampling Phased Array" technique, invented and developed by Fraunhofer IZFP, allows the acquisition of time signals (A-scans) for each individual transducer element of the array along with fast image reconstruction techniques based on synthetic focusing algorithms. The reconstruction considers the sound propagation from each image pixel to the individual sensor element. For anisotropic media, where the sound beam is deflected and the sound path is not known a-priori, a novel phase adjustment technique called "Reverse Phase Matching" is implemented. By taking into account the anisotropy and inhomogeneity of the weld structure, a ray tracing algorithm for modeling the acoustic wave propagation and calculating the sound propagation time is applied. This technique can be utilized for 2D and 3D real time image reconstruction. The

Tank Inspection NDE Results for Fiscal Year 2014, Waste Tanks 26, 27, 28 and 33

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

Elder, J.; Vandekamp, R.

2014-09-29

Ultrasonic nondestructive examinations (NDE) were performed on waste storage tanks 26, 27, 28 and 33 at the Savannah River Site as a part of the “In-Service Inspection (ISI) Program for High Level Waste Tanks.” No reportable conditions were identified during these inspections. The results indicate that the implemented corrosion control program continues to effectively mitigate corrosion in the SRS waste tanks. Ultrasonic inspection (UT) is used to detect general wall thinning, pitting and interface attack, as well as vertically oriented cracks through inspection of an 8.5 inch wide strip extending over the accessible height of the primary tank wall andmore » accessible knuckle regions. Welds were also inspected in tanks 27, 28 and 33 with no reportable indications. In a Type III/IIIA primary tank, a complete vertical strip includes scans of five plates (including knuckles) so five “plate/strips” would be completed at each vertical strip location. In FY 2014, a combined total of 79 plate/strips were examined for thickness mapping and crack detection, equating to over 45,000 square inches of area inspected on the primary tank wall. Of the 79 plate/strips examined in FY 2014 all but three have average thicknesses that remain at or above the construction minimum thickness which is nominal thickness minus 0.010 inches. There were no service induced reportable thicknesses or cracking encountered. A total of 2 pits were documented in 2014 with the deepest being 0.032 inches deep. One pit was detected in Tank 27 and one in Tank 33. No pitting was identified in Tanks 26 or 28. The maximum depth of any pit encountered in FY 2014 is 5% of nominal thickness, which is less than the minimum reportable criteria of 25% through-wall for pitting. In Tank 26 two vertical strips were inspected, as required by the ISI Program, due to tank conditions being outside normal chemistry controls for more than 3 months. Tank 28 had an area of localized thinning on the exterior wall

Considerations for ultrasonic testing application for on-orbit NDE

NASA Astrophysics Data System (ADS)

Koshti, Ajay M.

2015-04-01

The paper addresses some on-orbit nondestructive evaluation (NDE) needs of NASA for International Space Station (ISS). The presentation gives NDE requirements for inspecting suspect damage due to micro-meteoroids and orbital debris (MMOD) impact on the pressure wall of the ISS. This inspection is meant to be conducted from inside of the ISS module. The metallic wall of the module has a fixed wall thickness but also has integral orthogrid ribs for reinforcement. Typically, a single MMOD hit causes localized damage in a small area causing loss of material similar to pitting corrosion, but cracks may be present too. The impact may cause bulging of the wall. Results of the ultrasonic and eddy current demonstration scans on test samples are provided. The ultrasonic technique uses shear wave scans to interrogate the localized damage area from the surrounding undamaged area. The scanning protocol results in multiple scans, each with multiple "vee" paths. A superimposition and mosaic of the three-dimensional ultrasonic data from individual scans is desired to create C-scan images of the damage. This is a new data reduction process which is not currently implemented in state-of-art ultrasonic instruments. Results of ultrasonic scans on the simulated MMOD damage test plates are provided. The individual C-scans are superimposed manually creating mosaic of the inspection. The resulting image is compared with visibly detected damage boundaries, X-ray images, and localized ultrasonic and eddy current scans for locating crack tips to assess effectiveness of the ultrasonic scanning. The paper also discusses developments needed in improving ergonomics of the ultrasonic testing for on-orbit applications.

An Advanced Multi-Sensor Acousto-Ultrasonic Structural Health Monitoring System: Development and Aerospace Demonstration.

PubMed

Smithard, Joel; Rajic, Nik; van der Velden, Stephen; Norman, Patrick; Rosalie, Cedric; Galea, Steve; Mei, Hanfei; Lin, Bin; Giurgiutiu, Victor

2017-07-20

A key longstanding objective of the Structural Health Monitoring (SHM) research community is to enable the embedment of SHM systems in high value assets like aircraft to provide on-demand damage detection and evaluation. As against traditional non-destructive inspection hardware, embedded SHM systems must be compact, lightweight, low-power and sufficiently robust to survive exposure to severe in-flight operating conditions. Typical Commercial-Off-The-Shelf (COTS) systems can be bulky, costly and are often inflexible in their configuration and/or scalability, which militates against in-service deployment. Advances in electronics have resulted in ever smaller, cheaper and more reliable components that facilitate the development of compact and robust embedded SHM systems, including for Acousto-Ultrasonics (AU), a guided plate-wave inspection modality that has attracted strong interest due mainly to its capacity to furnish wide-area diagnostic coverage with a relatively low sensor density. This article provides a detailed description of the development, testing and demonstration of a new AU interrogation system called the Acousto Ultrasonic Structural health monitoring Array Module⁺ (AUSAM⁺). This system provides independent actuation and sensing on four Piezoelectric Wafer Active Sensor (PWAS) elements with further sensing on four Positive Intrinsic Negative (PIN) photodiodes for intensity-based interrogation of Fiber Bragg Gratings (FBG). The paper details the development of a novel piezoelectric excitation amplifier, which, in conjunction with flexible acquisition-system architecture, seamlessly provides electromechanical impedance spectroscopy for PWAS diagnostics over the full instrument bandwidth of 50 KHz-5 MHz. The AUSAM⁺ functionality is accessed via a simple hardware object providing a myriad of custom software interfaces that can be adapted to suit the specific requirements of each individual application.

An Advanced Multi-Sensor Acousto-Ultrasonic Structural Health Monitoring System: Development and Aerospace Demonstration

PubMed Central

Smithard, Joel; Rajic, Nik; Norman, Patrick; Rosalie, Cedric; Galea, Steve; Mei, Hanfei; Lin, Bin; Giurgiutiu, Victor

2017-01-01

A key longstanding objective of the Structural Health Monitoring (SHM) research community is to enable the embedment of SHM systems in high value assets like aircraft to provide on-demand damage detection and evaluation. As against traditional non-destructive inspection hardware, embedded SHM systems must be compact, lightweight, low-power and sufficiently robust to survive exposure to severe in-flight operating conditions. Typical Commercial-Off-The-Shelf (COTS) systems can be bulky, costly and are often inflexible in their configuration and/or scalability, which militates against in-service deployment. Advances in electronics have resulted in ever smaller, cheaper and more reliable components that facilitate the development of compact and robust embedded SHM systems, including for Acousto-Ultrasonics (AU), a guided plate-wave inspection modality that has attracted strong interest due mainly to its capacity to furnish wide-area diagnostic coverage with a relatively low sensor density. This article provides a detailed description of the development, testing and demonstration of a new AU interrogation system called the Acousto Ultrasonic Structural health monitoring Array Module+ (AUSAM+). This system provides independent actuation and sensing on four Piezoelectric Wafer Active Sensor (PWAS) elements with further sensing on four Positive Intrinsic Negative (PIN) photodiodes for intensity-based interrogation of Fiber Bragg Gratings (FBG). The paper details the development of a novel piezoelectric excitation amplifier, which, in conjunction with flexible acquisition-system architecture, seamlessly provides electromechanical impedance spectroscopy for PWAS diagnostics over the full instrument bandwidth of 50 KHz–5 MHz. The AUSAM+ functionality is accessed via a simple hardware object providing a myriad of custom software interfaces that can be adapted to suit the specific requirements of each individual application. PMID:28773193

Progress on automated data analysis algorithms for ultrasonic inspection of composites

NASA Astrophysics Data System (ADS)

Aldrin, John C.; Forsyth, David S.; Welter, John T.

2015-03-01

Progress is presented on the development and demonstration of automated data analysis (ADA) software to address the burden in interpreting ultrasonic inspection data for large composite structures. The automated data analysis algorithm is presented in detail, which follows standard procedures for analyzing signals for time-of-flight indications and backwall amplitude dropout. New algorithms have been implemented to reliably identify indications in time-of-flight images near the front and back walls of composite panels. Adaptive call criteria have also been applied to address sensitivity to variation in backwall signal level, panel thickness variation, and internal signal noise. ADA processing results are presented for a variety of test specimens that include inserted materials and discontinuities produced under poor manufacturing conditions. Software tools have been developed to support both ADA algorithm design and certification, producing a statistical evaluation of indication results and false calls using a matching process with predefined truth tables. Parametric studies were performed to evaluate detection and false call results with respect to varying algorithm settings.

Analytical Ultrasonics in Materials Research and Testing

NASA Technical Reports Server (NTRS)

Vary, A.

1986-01-01

Research results in analytical ultrasonics for characterizing structural materials from metals and ceramics to composites are presented. General topics covered by the conference included: status and advances in analytical ultrasonics for characterizing material microstructures and mechanical properties; status and prospects for ultrasonic measurements of microdamage, degradation, and underlying morphological factors; status and problems in precision measurements of frequency-dependent velocity and attenuation for materials analysis; procedures and requirements for automated, digital signal acquisition, processing, analysis, and interpretation; incentives for analytical ultrasonics in materials research and materials processing, testing, and inspection; and examples of progress in ultrasonics for interrelating microstructure, mechanical properites, and dynamic response.

The Potential of Sonic IR to Inspect Aircraft Components Traditionally Inspected with Fluorescent Penetrant and or Magnetic Particle Inspection

NASA Astrophysics Data System (ADS)

DiMambro, J.; Ashbaugh, D. M.; Han, X.; Favro, L. D.; Lu, J.; Zeng, Z.; Li, W.; Newaz, G. M.; Thomas, R. L.

2006-03-01

Sandia National Laboratories Airworthiness Assurance Nondestructive Inspection Validation Center (AANC) provides independent and quantitative evaluations of new and enhanced inspection, to developers, users, and regulators of aircraft. Wayne State University (WSU) has developed and patented an inspection technique using high-power ultrasonic excitation and infrared technology to detect defects in a variety of materials. AANC and WSU are working together as part of the FAA Sonic Infrared Technology Transfer Program. The ultimate goal of the program is to implement Sonic IR in the aviation field where appropriate. The capability of Sonic IR imaging to detect cracks in components commonly inspected with magnetic particle or liquid penetrant inspection in the field is of interest to industry.

Rapid Ultrasonic Inspection of Artillery Projectiles

DTIC Science & Technology

1980-11-01

field behavior as a function of gap separation d 26 Fig. 14 Electromagnet equivalent circuit model use for final design of yoke, pole pieces and...card 64 Fig. 37 Frequency response of receiver circuit 66 Fig. 38 a) Configuration of EMAT used to launch both longitudinal and circumferential... circuit for OD and ID location 88 Fig. 51 Photograph of fully assembled EMAT inspection system during projectile inspection 92 Fig. 52 Sequence

Improvement in Magnetic Techniques for Rail Inspection

DOT National Transportation Integrated Search

1981-06-01

Current inspection of rail for internal defects is carried out by ultrasonic and/or magnetic technique for inspecting rail for internal flaws. The major emphasis was placed on improving the speed and detectability of current techniques. Experimental ...

Nondestructive ultrasonic characterization of engineering materials

NASA Technical Reports Server (NTRS)

Salama, K.

1985-01-01

The development of an ultrasonic method for the nondestructive characterization of mechanical properties of engineering material is described. The method utilizes the nonlinearity parameter measurement which describes the anharmonic behavior of the solid through measurements of amplitudes of the fundamental and of the generated second harmonic ultrasonic waves. The nonlinearity parameter is also directly related to the acoustoelastic constant of the solid which can be determined by measuring the linear dependence of ultrasonic velocity on stress. A major advantage of measurements of the nonlinearity parameter over that of the acoustoelastic constant is that it may be determined without the application of stress on the material, which makes it more applicable for in-service nondestructive characterization. The relationships between the nonlinearity parameter of second-harmonic generation and the percentage of solid solution phase in engineering materials such as heat treatable aluminum alloys was established. The acoustoelastic constants are measured on these alloys for comparison and confirmation. A linear relationship between the nonlinearity parameter and the volume fraction of second phase precipitates in the alloys is indicated.

Composite Characterization Using Ultrasonic Wavefield Techniques

NASA Technical Reports Server (NTRS)

Leckey, Cara A. C.; Juarez, Peter D.; Seebo, Jeffrey P.

2016-01-01

The large-scale use of composite components in aerospace applications is expected to continue due to the benefits of composite materials, such as reduced weight, increased strength, and tailorability. NASA's Advanced Composites Project (ACP) has the goals of reducing the timeline for certification of composite materials and enabling the expanded use of advanced composite materials. A key technical challenge area for accomplishing these goals is the need for nondestructive evaluation and materials characterization techniques that are optimized for rapid inspection and detailed defect/damage characterization in composite materials. This presentation will discuss ongoing research investigating the use of ultrasonic wavefield techniques for the characterization of defects such as fiber waviness and delamination damage. Ongoing work includes the development of realistic ultrasonic simulation tools for use in predicting the inspectability of composites and optimizing inspection methodologies. Recent studies on detecting/characterizing delamination damage and fiber waviness via wavefield methods will be described.

Bulk-wave ultrasonic propagation imagers

NASA Astrophysics Data System (ADS)

Abbas, Syed Haider; Lee, Jung-Ryul

2018-03-01

Laser-based ultrasound systems are described that utilize the ultrasonic bulk-wave sensing to detect the damages and flaws in the aerospace structures. These systems apply pulse-echo or through transmission methods to detect longitudinal through-the-thickness bulk-waves. These thermoelastic waves are generated using Q-switched laser and non-contact sensing is performed using a laser Doppler vibrometer (LDV). Laser-based raster scanning is performed by either twoaxis translation stage for linear-scanning or galvanometer-based laser mirror scanner for angular-scanning. In all ultrasonic propagation imagers, the ultrasonic data is captured and processed in real-time and the ultrasonic propagation can be visualized during scanning. The scanning speed can go up to 1.8 kHz for two-axis linear translation stage based B-UPIs and 10 kHz for galvanometer-based laser mirror scanners. In contrast with the other available ultrasound systems, these systems have the advantage of high-speed, non-contact, real-time, and non-destructive inspection. In this paper, the description of all bulk-wave ultrasonic imagers (B-UPIs) are presented and their advantages are discussed. Experiments are performed with these system on various structures to proof the integrity of their results. The C-scan results produced from non-dispersive, through-the-thickness, bulk-wave detection show good agreement in detection of structural variances and damage location in all inspected structures. These results show that bulk-wave UPIs can be used for in-situ NDE of engineering structures.

High-Performance Acousto-Ultrasonic Scan System Being Developed

NASA Technical Reports Server (NTRS)

Roth, Don J.; Martin, Richard E.; Cosgriff, Laura M.; Gyekenyesi, Andrew L.; Kautz, Harold E.

2003-01-01

Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation (NDE) technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition and distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods, such as ultrasonic cscan, x-ray radiography, and thermographic inspection, which tend to be used primarily for discrete flaw detection. Throughout its history, AU has been used to inspect polymer matrix composites, metal matrix composites, ceramic matrix composites, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. This year, essential AU technology was reviewed. In addition, the basic hardware and software configuration for the scanner was developed, and preliminary results with the system were described. Mechanical and environmental loads applied to composite materials can cause distributed damage (as well as discrete defects) that plays a significant role in the degradation of physical properties. Such damage includes fiber/matrix debonding (interface failure), matrix microcracking, and fiber fracture and buckling. Investigations at the NASA Glenn Research Center have shown that traditional NDE scan inspection methods such as ultrasonic c-scan, x-ray imaging, and thermographic imaging tend to be more suited to discrete defect detection rather than the characterization of accumulated distributed micro-damage in composites. Since AU is focused on assessing the distributed micro-damage state of the material in between the sending and receiving transducers, it has proven to be quite suitable for assessing the relative composite material state. One major success story at Glenn with AU measurements has been the correlation between the ultrasonic decay rate obtained during AU

High-Performance Acousto-Ultrasonic Scan System Being Developed

NASA Technical Reports Server (NTRS)

Roth, Don J.; Martin, Richard E.; Cosgriff, Laura M.; Gyekenyesi, Andrew L.; Kautz, Harold E.

2003-01-01

Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation (NDE) technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition and distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods, such as ultrasonic cscan, x-ray radiography, and thermographic inspection, which tend to be used primarily for discrete flaw detection. Throughout its history, AU has been used to inspect polymer matrix composites, metal matrix composites, ceramic matrix composites, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. This year, essential AU technology was reviewed. In addition, the basic hardware and software configuration for the scanner was developed, and preliminary results with the system were described. Mechanical and environmental loads applied to composite materials can cause distributed damage (as well as discrete defects) that plays a significant role in the degradation of physical properties. Such damage includes fiber/matrix debonding (interface failure), matrix microcracking, and fiber fracture and buckling. Investigations at the NASA Glenn Research Center have shown that traditional NDE scan inspection methods such as ultrasonic c-scan, x-ray imaging, and thermographic imaging tend to be more suited to discrete defect detection rather than the characterization of accumulated distributed microdamage in composites. Since AU is focused on assessing the distributed microdamage state of the material in between the sending and receiving transducers, it has proven to be quite suitable for assessing the relative composite material state. One major success story at Glenn with AU measurements has been the correlation between the ultrasonic decay rate obtained during AU

Inspecting Composites with Airborne Ultrasound: Through Thick and Thin

NASA Astrophysics Data System (ADS)

Hsu, David K.; Barnard, Daniel J.

2006-03-01

The inspection of composite materials and structures with air-coupled ultrasound has the obvious advantage that it is non-contact, non-contaminating, and free from couplants. However, the transmission efficiency from air to solid is extremely low due to the enormous difference in acoustic impedance. The development of more efficient airborne ultrasonic transducers over the years has made it possible, and even practical, to inspect composites with airborne ultrasound. It is now possible to drive newer, more efficient transducers with a portable ultrasonic flaw detector to inspect 2-inch thick solid CFRP in air. In this paper we describe our experience in applying air-coupled ultrasound to the inspection of a variety of composite structures, from honeycomb with thin composite facesheet to very thick solid laminates. General considerations for making airborne ultrasonic measurement in composite are given, and mechanism of transmission through honeycomb core, and resonance effects in transmitting through thick laminates will be described. NDE results of defects and damage in various composite structures will be presented.

Risk assessment of turbine rotor failure using probabilistic ultrasonic non-destructive evaluations

NASA Astrophysics Data System (ADS)

Guan, Xuefei; Zhang, Jingdan; Zhou, S. Kevin; Rasselkorde, El Mahjoub; Abbasi, Waheed A.

2014-02-01

The study presents a method and application of risk assessment methodology for turbine rotor fatigue failure using probabilistic ultrasonic nondestructive evaluations. A rigorous probabilistic modeling for ultrasonic flaw sizing is developed by incorporating the model-assisted probability of detection, and the probability density function (PDF) of the actual flaw size is derived. Two general scenarios, namely the ultrasonic inspection with an identified flaw indication and the ultrasonic inspection without flaw indication, are considered in the derivation. To perform estimations for fatigue reliability and remaining useful life, uncertainties from ultrasonic flaw sizing and fatigue model parameters are systematically included and quantified. The model parameter PDF is estimated using Bayesian parameter estimation and actual fatigue testing data. The overall method is demonstrated using a realistic application of steam turbine rotor, and the risk analysis under given safety criteria is provided to support maintenance planning.

Flaw characterization through nonlinear ultrasonics and wavelet cross-correlation algorithms

NASA Astrophysics Data System (ADS)

Bunget, Gheorghe; Yee, Andrew; Stewart, Dylan; Rogers, James; Henley, Stanley; Bugg, Chris; Cline, John; Webster, Matthew; Farinholt, Kevin; Friedersdorf, Fritz

2018-04-01

Ultrasonic measurements have become increasingly important non-destructive techniques to characterize flaws found within various in-service industrial components. The prediction of remaining useful life based on fracture analysis depends on the accurate estimation of flaw size and orientation. However, amplitude-based ultrasonic measurements are not able to estimate the plastic zones that exist ahead of crack tips. Estimating the size of the plastic zone is an advantage since some flaws may propagate faster than others. This paper presents a wavelet cross-correlation (WCC) algorithm that was applied to nonlinear analysis of ultrasonically guided waves (GW). By using this algorithm, harmonics present in the waveforms were extracted and nonlinearity parameters were used to indicate both the tip of the cracks and size of the plastic zone. B-scans performed with the quadratic nonlinearities were sensitive to micro-damage specific to plastic zones.

Literature Review: Theory and Application of In-Line Inspection Technologies for Oil and Gas Pipeline Girth Weld Defection

PubMed Central

Feng, Qingshan; Li, Rui; Nie, Baohua; Liu, Shucong; Zhao, Lianyu; Zhang, Hong

2016-01-01

Girth weld cracking is one of the main failure modes in oil and gas pipelines; girth weld cracking inspection has great economic and social significance for the intrinsic safety of pipelines. This paper introduces the typical girth weld defects of oil and gas pipelines and the common nondestructive testing methods, and systematically generalizes the progress in the studies on technical principles, signal analysis, defect sizing method and inspection reliability, etc., of magnetic flux leakage (MFL) inspection, liquid ultrasonic inspection, electromagnetic acoustic transducer (EMAT) inspection and remote field eddy current (RFDC) inspection for oil and gas pipeline girth weld defects. Additionally, it introduces the new technologies for composite ultrasonic, laser ultrasonic, and magnetostriction inspection, and provides reference for development and application of oil and gas pipeline girth weld defect in-line inspection technology. PMID:28036016

A Method For The Verification Of Wire Crimp Compression Using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Cramer, K. E.; Perey, Daniel F.; Yost, William t.

2010-01-01

The development of a new ultrasonic measurement technique to assess quantitatively wire crimp terminations is discussed. The amplitude change of a compressional ultrasonic wave propagating at right angles to the wire axis and through the junction of a crimp termination is shown to correlate with the results of a destructive pull test, which is a standard for assessing crimp wire junction quality. To demonstrate the technique, the case of incomplete compression of crimped connections is ultrasonically tested, and the results are correlated with pull tests. Results show that the nondestructive ultrasonic measurement technique consistently predicts good crimps when the ultrasonic transmission is above a certain threshold amplitude level. A quantitative measure of the quality of the crimped connection based on the ultrasonic energy transmitted is shown to respond accurately to crimp quality. A wave propagation model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying this technique while wire crimps are installed is also presented. The instrument is based on a two-jaw type crimp tool suitable for butt-splice type connections. A comparison of the results of two different instruments is presented and shows reproducibility between instruments within a 95% confidence bound.

Airborne ultrasonic inspection of hides and leather

USDA-ARS?s Scientific Manuscript database

Currently, hides and leather are visually inspected and ranked for quality, sale price and usable area. Visual inspection is not reliable for detecting defects, which are usually hidden inside the material. This manual assessment is non-uniform among operators, and often leads to disputes over fai...

Advances in model-based software for simulating ultrasonic immersion inspections of metal components

NASA Astrophysics Data System (ADS)

Chiou, Chien-Ping; Margetan, Frank J.; Taylor, Jared L.; Engle, Brady J.; Roberts, Ronald A.

2018-04-01

Under the sponsorship of the National Science Foundation's Industry/University Cooperative Research Center at ISU, an effort was initiated in 2015 to repackage existing research-grade software into user-friendly tools for the rapid estimation of signal-to-noise ratio (SNR) for ultrasonic inspections of metals. The software combines: (1) a Python-based graphical user interface for specifying an inspection scenario and displaying results; and (2) a Fortran-based engine for computing defect signals and backscattered grain noise characteristics. The later makes use the Thompson-Gray measurement model for the response from an internal defect, and the Thompson-Margetan independent scatterer model for backscattered grain noise. This paper, the third in the series [1-2], provides an overview of the ongoing modeling effort with emphasis on recent developments. These include the ability to: (1) treat microstructures where grain size, shape and tilt relative to the incident sound direction can all vary with depth; and (2) simulate C-scans of defect signals in the presence of backscattered grain noise. The simulation software can now treat both normal and oblique-incidence immersion inspections of curved metal components. Both longitudinal and shear-wave inspections are treated. The model transducer can either be planar, spherically-focused, or bi-cylindrically-focused. A calibration (or reference) signal is required and is used to deduce the measurement system efficiency function. This can be "invented" by the software using center frequency and bandwidth information specified by the user, or, alternatively, a measured calibration signal can be used. Defect types include flat-bottomed-hole reference reflectors, and spherical pores and inclusions. Simulation outputs include estimated defect signal amplitudes, root-mean-square values of grain noise amplitudes, and SNR as functions of the depth of the defect within the metal component. At any particular depth, the user can view

Guided-waves technique for inspecting the health of wall-covered building risers

NASA Astrophysics Data System (ADS)

Tse, Peter W.; Chen, J. M.; Wan, X.

2015-03-01

The inspection technique uses guided ultrasonic waves (GW) has been proven effective in detecting pipes' defects. However, as of today, the technique has not attracted much market attention because of insufficient field tests and lack of traceable records with proven results in commercial applications. In this paper, it presents the results obtained by using GW to inspect the defects occurred in real gas risers that are commonly installed in tall buildings. The purpose of having risers is to deliver gas from any building external piping system to each household unit of the building. The risers extend from the external wall of the building, penetrate thorough the concrete wall, into the kitchen or bathroom of each household unit. Similar to in-service pipes, risers are prone to corrosion due to water leaks into the concrete wall. However, the corrosion occurs in the section of riser, which is covered by the concrete wall, is difficult to be inspected by conventional techniques. Hence, GW technique was employed. The effectiveness of GW technique was tested by laboratory and on-site experiments using real risers gathered from tall buildings. The experimental results show that GW can partially penetrate thorough the riser's section that is covered by wall. The integrity of the wall-covered section of a riser can be determined by the reflected wave signals generated by the corroded area that may exit inside the wall-covered section. Based on the reflected wave signal, one can determine the health of the wall-covered riser.

Concurrent ultrasonic weld evaluation system

DOEpatents

Hood, Donald W.; Johnson, John A.; Smartt, Herschel B.

1987-01-01

A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws.

Concurrent ultrasonic weld evaluation system

DOEpatents

Hood, D.W.; Johnson, J.A.; Smartt, H.B.

1985-09-04

A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws.

The Application of Ultrasonic Inspection to Crimped Electrical Connections

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2010-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp terminations is discussed. The development of a prototype instrument, based on a modified, commercially available, crimp tool, is demonstrated for applying this technique when wire crimps are installed. The crimp tool has three separate crimping locations that accommodate the three different ferrule diameters. The crimp tool in this study is capable of crimping wire diameters ranging from 12 to 26 American Wire Gauge (AWG). A transducer design is presented that allows for interrogation of each of the three crimp locations on the crimp tool without reconfiguring the device. An analysis methodology, based on transmitted ultrasonic energy and timing of the first received pulse is shown to correlate to both crimp location in the tool and the AWG of the crimp/ferrule combination. The detectability of a number of the crimp failure pathologies, such as missing strands, partially inserted wires and incomplete crimp compression, is discussed. A wave propagation model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process.

Immersion probe arrays for rapid pipeline weld inspection

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

Lebsack, S.; Heckhauser, H.

In 1992, F.H. Gottfeld, Herne, Germany, a member of the SGA Group (Societe Generale de Surveillance) and Krautkramer Branson, Koin, undertook production of a rapid automated ultrasonic testing (UT) system to inspect manually and machine welded pipeline girth welds. The result of the project is a system called MIPA, or multiple immersion probe array. The advantages of using UT to detect certain weld defects have been realized for many years, however for some applications the time required for UT has been a limiting factor. Where time has not been a factor, automated ultrasonic technology has advanced a reliable solution tomore » many inspection problems across a broad industrial base. The recent past has seen the entrance of automated ultrasonic technology into the harsh and demanding environment of pipelay operations, However, the use of these systems has been focused on automated welding processes. Their effectiveness for manual pipeline welding inspection is contested. This is due to the infinite variability of the joint alignment and shape that is unavoidable even when highly skilled welders are used.« less

Concurrent ultrasonic weld evaluation system

DOEpatents

Hood, D.W.; Johnson, J.A.; Smartt, H.B.

1987-12-15

A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder is disclosed. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws. 5 figs.

Helping Teachers Become Inservice Facilitators. A Training Program to Develop School-Based Inservice Planning Teams. Seventh Edition. Inservice Series No. 6.

ERIC Educational Resources Information Center

Wilson, Mary Alice B.

This manual is designed for the training of inservice facilitator teams, which include regular and special education teachers, administrators, and other school district staff. Inservice facilitator teams are defined as teams which develop inservice programs for their school system. Each chapter focuses on a specific skill for the training teams;…

Bruce Thompson: Adventures and advances in ultrasonic backscatter

NASA Astrophysics Data System (ADS)

Margetan, Frank J.

2012-05-01

Over the course of his professional career Dr. R. Bruce Thompson published several hundred articles on non-destructive evaluation, the majority dealing with topics in ultrasonics. One longtime research interest of Dr. Thompson, with applications both to microstructure characterization and defect detection, was backscattered grain noise in metals. Over a 20 year period he led a revolving team of staff members and graduate students investigating various aspects of ultrasonic backscatter. As a member of that team I had the privilege of working along side Dr. Thompson for many years, serving as a sort of Dr. Watson to Bruce's Sherlock Holmes. This article discusses Dr. Thompson's general approaches to modeling backscatter, the research topics he chose to explore to systematically elucidate a better understanding of the phenomena, and the many contributions to the field achieved under his leadership. The backscatter work began in earnest around 1990, motivated by a need to improve inspections of aircraft engine components. At that time Dr. Thompson launched two research efforts. The first led to the heuristic Independent Scatterer Model which could be used to estimate the average grain noise level that would be seen in any given ultrasonic inspection. There the contribution from the microstructure was contained in a measureable parameter known as the Figure-of-Merit or FOM. The second research effort, spearheaded by Dr. Jim Rose, led to a formal relationship between FOM and details of the metal microstructure. The combination of the Independent Scattering Model and Rose's formalism provided a powerful tool for investigating backscatter in metals. In this article model developments are briefly reviewed and several illustrative applications are discussed. These include: the determination of grain size and shape from ultrasonic backscatter; grain noise variability in engine-titanium billets and forgings; and the design of ultrasonic inspection systems to improve defect

Development of a High Level Waste Tank Inspection System

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

Appel, D.K.; Loibl, M.W.; Meese, D.C.

1995-03-21

The Westinghouse Savannah River Technology Center was requested by it`s sister site, West Valley Nuclear Service (WVNS), to develop a remote inspection system to gather wall thickness readings of their High Level Waste Tanks. WVNS management chose to take a proactive approach to gain current information on two tanks t hat had been in service since the early 70`s. The tanks contain high level waste, are buried underground, and have only two access ports to an annular space between the tank and the secondary concrete vault. A specialized remote system was proposed to provide both a visual surveillance and ultrasonicmore » thickness measurements of the tank walls. A magnetic wheeled crawler was the basis for the remote delivery system integrated with an off-the-shelf Ultrasonic Data Acquisition System. A development program was initiated for Savannah River Technology Center (SRTC) to design, fabricate, and test a remote system based on the Crawler. The system was completed and involved three crawlers to perform the needed tasks, an Ultrasonic Crawler, a Camera Crawler, and a Surface Prep Crawler. The crawlers were computer controlled so that their operation could be done remotely and their position on the wall could be tracked. The Ultrasonic Crawler controls were interfaced with ABB Amdata`s I-PC, Ultrasonic Data Acquisition System so that thickness mapping of the wall could be obtained. A second system was requested by Westinghouse Savannah River Company (WSRC), to perform just ultrasonic mapping on their similar Waste Storage Tanks; however, the system needed to be interfaced with the P-scan Ultrasonic Data Acquisition System. Both remote inspection systems were completed 9/94. Qualifications tests were conducted by WVNS prior to implementation on the actual tank and tank development was achieved 10/94. The second inspection system was deployed at WSRC 11/94 with success, and the system is now in continuous service inspecting the remaining high level waste tanks

Stochastic simulation for the propagation of high-frequency acoustic waves through a random velocity field

NASA Astrophysics Data System (ADS)

Lu, B.; Darmon, M.; Leymarie, N.; Chatillon, S.; Potel, C.

2012-05-01

In-service inspection of Sodium-Cooled Fast Reactors (SFR) requires the development of non-destructive techniques adapted to the harsh environment conditions and the examination complexity. From past experiences, ultrasonic techniques are considered as suitable candidates. The ultrasonic telemetry is a technique used to constantly insure the safe functioning of reactor inner components by determining their exact position: it consists in measuring the time of flight of the ultrasonic response obtained after propagation of a pulse emitted by a transducer and its interaction with the targets. While in-service the sodium flow creates turbulences that lead to temperature inhomogeneities, which translates into ultrasonic velocity inhomogeneities. These velocity variations could directly impact the accuracy of the target locating by introducing time of flight variations. A stochastic simulation model has been developed to calculate the propagation of ultrasonic waves in such an inhomogeneous medium. Using this approach, the travel time is randomly generated by a stochastic process whose inputs are the statistical moments of travel times known analytically. The stochastic model predicts beam deviations due to velocity inhomogeneities, which are similar to those provided by a determinist method, such as the ray method.

Method and apparatus for inspecting conduits

DOEpatents

Spisak, Michael J.; Nance, Roy A.

1997-01-01

An apparatus and method for ultrasonic inspection of a conduit are provided. The method involves directing a first ultrasonic pulse at a particular area of the conduit at a first angle, receiving the reflected sound from the first ultrasonic pulse, substantially simultaneously or subsequently in very close time proximity directing a second ultrasonic pulse at said area of the conduit from a substantially different angle than said first angle, receiving the reflected sound from the second ultrasonic pulse, and comparing the received sounds to determine if there is a defect in that area of the conduit. The apparatus of the invention is suitable for carrying out the above-described method. The method and apparatus of the present invention provide the ability to distinguish between sounds reflected by defects in a conduit and sounds reflected by harmless deposits associated with the conduit.

The cavitation erosion of ultrasonic sonotrode during large-scale metallic casting: Experiment and simulation.

PubMed

Tian, Yang; Liu, Zhilin; Li, Xiaoqian; Zhang, Lihua; Li, Ruiqing; Jiang, Ripeng; Dong, Fang

2018-05-01

Ultrasonic sonotrodes play an essential role in transmitting power ultrasound into the large-scale metallic casting. However, cavitation erosion considerably impairs the in-service performance of ultrasonic sonotrodes, leading to marginal microstructural refinement. In this work, the cavitation erosion behaviour of ultrasonic sonotrodes in large-scale castings was explored using the industry-level experiments of Al alloy cylindrical ingots (i.e. 630 mm in diameter and 6000 mm in length). When introducing power ultrasound, severe cavitation erosion was found to reproducibly occur at some specific positions on ultrasonic sonotrodes. However, there is no cavitation erosion present on the ultrasonic sonotrodes that were not driven by electric generator. Vibratory examination showed cavitation erosion depended on the vibration state of ultrasonic sonotrodes. Moreover, a finite element (FE) model was developed to simulate the evolution and distribution of acoustic pressure in 3-D solidification volume. FE simulation results confirmed that significant dynamic interaction between sonotrodes and melts only happened at some specific positions corresponding to severe cavitation erosion. This work will allow for developing more advanced ultrasonic sonotrodes with better cavitation erosion-resistance, in particular for large-scale castings, from the perspectives of ultrasonic physics and mechanical design. Copyright © 2018 Elsevier B.V. All rights reserved.

Mid-IR laser ultrasonic testing for fiber reinforced plastics

NASA Astrophysics Data System (ADS)

Kusano, Masahiro; Hatano, Hideki; Oguchi, Kanae; Yamawaki, Hisashi; Watanabe, Makoto; Enoki, Manabu

2018-04-01

Ultrasonic testing is the most common method to detect defects in materials and evaluate their sizes and locations. Since piezo-electric transducers are manually handled from point to point, it takes more costs for huge products such as airplanes. Laser ultrasonic testing (LUT) is a breakthrough technique. A pulsed laser generates ultrasonic waves on a material surface due to thermoelastic effect or ablation. The ultrasonic waves can be detected by another laser with an interferometer. Thus, LUT can realize instantaneous inspection without contacting a sample. A pulse laser with around 3.2 μm wavelength (in the mid-IR range) is more suitable to generate ultrasonic waves for fiber reinforced plastics (FRPs) because the light is well absorbed by the polymeric matrix. On the other hand, such a laser is not available in the market. In order to emit the mid-IR laser pulse, we came up with the application of an optical parametric oscillator and developed an efficient wavelength conversion device by pumping a compact Nd:YAG solid-state laser. Our mid-IR LUT system is most suitable for inspection of FRPs. The signal-to-noise ratio of ultrasonic waves generated by the mid-IR laser is higher than that by the Nd:YAG laser. The purpose of the present study is to evaluate the performance of the mid-IR LUT system in reflection mode. We investigated the effects of the material properties and the laser properties on the generated ultrasonic waves. In addition, C-scan images by the system were also presented.

Final Environmental Assessment: Proposed Composite Aircraft Inspection Facilities, Hill Air Force Base, Utah

DTIC Science & Technology

2008-10-02

radiography . Two large inspection bays would each accommodate one F-22 aircraft and robotic x-ray inspection equipment. Six smaller bays would accommodate...large aircraft components (two ultrasonic inspection bays, two laser shearography inspection bays, and two digital radiography inspection bays...Hill Air Force Base, Utah Final Environmental Assessment: Proposed Composite Aircraft Inspection Facilities, Hill Air Force Base, Utah

Method for assessing in-service motor efficiency and in-service motor/load efficiency

DOEpatents

Kueck, John D.; Otaduy, Pedro J.

1997-01-01

A method and apparatus for assessing the efficiency of an in-service motor. The operating characteristics of the in-service motor are remotely measured. The operating characteristics are then applied to an equivalent circuit for electrical motors. Finally the equivalent circuit is evaluated to determine the performance characteristics of said in-service motor. Based upon the evaluation an individual is able to determine the rotor speed, power output, efficiency, and toque of the in-service motor. Additionally, an individual is able to confirm the calculations by comparing measured values with values obtained as a result of the motor equivalent circuit evaluation.

Pulsed infrared thermography for assessment of ultrasonic welds

NASA Astrophysics Data System (ADS)

McGovern, Megan E.; Rinker, Teresa J.; Sekol, Ryan C.

2018-03-01

Battery packs are a critical component in electric vehicles. During pack assembly, the battery cell tab and busbar are ultrasonically welded. The properties of the welds ultimately affect battery pack durability. Quality inspection of these welds is important to ensure durable battery packs. Pack failure is detrimental economically and could also pose a safety hazard, such as thermal runaway. Ultrasonic welds are commonly checked by measuring electrical resistance or auditing using destructive mechanical testing. Resistance measurements are quick, but sensitive to set-up changes. Destructive testing cannot represent the entire weld set. It is possible for a weak weld to satisfy the electrical requirement check, because only sufficient contact between the tabs and busbar is required to yield a low resistance measurement. Laboratory techniques are often not suitable for inline inspection, as they may be time-consuming, use couplant, or are only suitable for coupons. The complex surface geometry also poses difficulties for conventional nondestructive techniques. A method for inspection of ultrasonic welds is proposed using pulsed infrared thermography to identify discrepant welds in a manufacturing environment. Thermal measurements of welds were compared to electrical and mechanical measurements. The heat source distribution was calculated to obtain thermal images with high temporal and spatial resolution. All discrepant welds were readily identifiable using two thermographic techniques: pixel counting and the gradient image. A positive relationship between pixel count and mechanical strength was observed. The results demonstrate the potential of pulsed thermography for inline inspection, which can complement, or even replace, conventional electrical resistance measurements.

Non-Destructive Inspection of Impact Damage in Composite Aircraft Panels by Ultrasonic Guided Waves and Statistical Processing.

PubMed

Capriotti, Margherita; Kim, Hyungsuk E; Scalea, Francesco Lanza di; Kim, Hyonny

2017-06-04

This paper discusses a non-destructive evaluation (NDE) technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI) from ground service equipment (GSE), such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers.

Device for inspecting vessel surfaces

DOEpatents

Appel, D. Keith

1995-01-01

A portable, remotely-controlled inspection crawler for use along the walls of tanks, vessels, piping and the like. The crawler can be configured to use a vacuum chamber for supporting itself on the inspected surface by suction or a plurality of magnetic wheels for moving the crawler along the inspected surface. The crawler is adapted to be equipped with an ultrasonic probe for mapping the structural integrity or other characteristics of the surface being inspected. Navigation of the crawler is achieved by triangulation techniques between a signal transmitter on the crawler and a pair of microphones attached to a fixed, remote location, such as the crawler's deployment unit. The necessary communications are established between the crawler and computers external to the inspection environment for position control and storage and/or monitoring of data acquisition.

Noninvasive ultrasonic examination technology in support of counter-terrorism and drug interdiction activities: the acoustic inspection device (AID)

NASA Astrophysics Data System (ADS)

Diaz, Aaron A.; Burghard, Brion J.; Skorpik, James R.; Shepard, Chester L.; Samuel, Todd J.; Pappas, Richard A.

2003-07-01

The Pacific Northwest National Laboratory (PNNL) has developed a portable, battery-operated, handheld ultrasonic device that provides non-invasive container interrogation and material identification capabilities. The technique governing how the acoustic inspection device (AID) functions, involves measurements of ultrasonic pulses (0.1 to 5 MHz) that are launched into a container or material. The return echoes from these pulses are analyzed in terms of time-of-flight and frequency content to extract physical property measurements (the acoustic velocity and attenuation coefficient) of the material under test. The AID performs an automated analysis of the return echoes to identify the material, and detect contraband in the form of submerged packages and concealed compartments in liquid filled containers and solid-form commodities. An inspector can quickly interrogate outwardly innocuous commodity items such as shipping barrels, tanker trucks, and metal ingots. The AID can interrogate container sizes ranging from approximately 6 inches in diameter to over 96 inches in diameter and allows the inspector to sort liquid and material types into groups of like and unlike; a powerful method for discovering corrupted materials or miss-marked containers co-mingled in large shipments. This manuscript describes the functionality, capabilities and measurement methodology of the technology as it relates to homeland security applications.

Inspection of baked carbon anodes using a combination of multi-spectral acousto-ultrasonic techniques and principal component analysis.

PubMed

Boubaker, Moez Ben; Picard, Donald; Duchesne, Carl; Tessier, Jayson; Alamdari, Houshang; Fafard, Mario

2018-05-17

This paper reports on the application of an acousto-ultrasonic (AU) scheme for the inspection of industrial-size carbon anode blocks used in the production of primary aluminium by the Hall-Héroult process. A frequency-modulated wave is used to excite the anode blocks at multiple points. The collected attenuated AU signals are decomposed using the Discrete Wavelet Transform (DTW) after which vectors of features are calculated. Principal Component Analysis (PCA) is utilized to cluster the AU responses of the anodes. The approach allows locating cracks in the blocks and the AU features were found sensitive to crack severity. The results are validated using images collected after cutting some anodes. Copyright © 2018 Elsevier B.V. All rights reserved.

Semi-Automated Pulse-Echo Ultrasonic System for Inspecting Tires

DOT National Transportation Integrated Search

1977-07-01

A nondestructive tire-testing system has been developed using the pulse-echo ultrasonic technique, which offers substantial advantages over all other physical nondestructive-testing methods and shows promise of reducing the cost of production-tire in...

Computer Automated Ultrasonic Inspection System

DTIC Science & Technology

1985-02-06

Reports 74 3.1.4 Statistical Analysis Capability 74 3.2 Nondestructive Evaluation Terminal Hardware 76 3.3 Nondestructive Evaluation Terminal Vendor...3.4.2.6 Create a Hold Tape 103 vi TABLE OF CONTENTS SECTION PAGE 3.4.3 System Status 104 3.4.4 Statistical Analysis 105 3.4.4.1 Statistical Analysis...Data Extraction 105 3.4.4.2 Statistical Analysis Report and Display Generation 106 3.4.5 Quality Assurance Reports 106 3.4.6 Nondestructive Inspection

Detection and Sizing of Fatigue Cracks in Steel Welds with Advanced Eddy Current Techniques

NASA Astrophysics Data System (ADS)

Todorov, E. I.; Mohr, W. C.; Lozev, M. G.

2008-02-01

Butt-welded specimens were fatigued to produce cracks in the weld heat-affected zone. Advanced eddy current (AEC) techniques were used to detect and size the cracks through a coating. AEC results were compared with magnetic particle and phased-array ultrasonic techniques. Validation through destructive crack measurements was also conducted. Factors such as geometry, surface treatment, and crack tightness interfered with depth sizing. AEC inspection techniques have the potential of providing more accurate and complete sizing flaw data for manufacturing and in-service inspections.

Development of Inspection for Friction Stir Welds for Rocket Fuel Tanks

NASA Technical Reports Server (NTRS)

Russell, Samuel S.

2012-01-01

During development of the Ares I weld processes nondestructive and destructive testing were used to identify and characterize defects that occurred. These defects were named and character noted. This catalogue of defects and characteristics was then used to develop inspection methods for Self Reacting Friction Stir Welds (SR ]FSW) and Conventional Friction Stir Welds (C ]FSW). Dye penetrant, eddy current, x ]radiography, single element ultrasonic, and phased array ultrasonic (PAUT) inspection procedures were developed to target the expected defects. Once the method procedure was developed a comparison was performed to allow for selection of the best inspection method. Tests of the effectiveness of the inspection were performed on purposely fabricated flawed specimens and electrodischarge machined notches. The initial test results prompted a revisit of the PAUT procedure and a redesign of the inspection. Subsequent testing showed that a multi ]angle PAUT inspection resulted in better detection capability. A discussion of the most effective orientations of the PAUT transducer will be presented. Also, the implementation of the inspection on production hardware will be presented. In some cases the weld tool is used as the transducer manipulator and in some cases a portable scanner is used

Real-time ultrasonic weld evaluation system

NASA Astrophysics Data System (ADS)

Katragadda, Gopichand; Nair, Satish; Liu, Harry; Brown, Lawrence M.

1996-11-01

Ultrasonic testing techniques are currently used as an alternative to radiography for detecting, classifying,and sizing weld defects, and for evaluating weld quality. Typically, ultrasonic weld inspections are performed manually, which require significant operator expertise and time. Thus, in recent years, the emphasis is to develop automated methods to aid or replace operators in critical weld inspections where inspection time, reliability, and operator safety are major issues. During this period, significant advances wee made in the areas of weld defect classification and sizing. Very few of these methods, however have found their way into the market, largely due to the lack of an integrated approach enabling real-time implementation. Also, not much research effort was directed in improving weld acceptance criteria. This paper presents an integrated system utilizing state-of-the-art techniques for a complete automation of the weld inspection procedure. The modules discussed include transducer tracking, classification, sizing, and weld acceptance criteria. Transducer tracking was studied by experimentally evaluating sonic and optical position tracking techniques. Details for this evaluation are presented. Classification is obtained using a multi-layer perceptron. Results from different feature extraction schemes, including a new method based on a combination of time and frequency-domain signal representations are given. Algorithms developed to automate defect registration and sizing are discussed. A fuzzy-logic acceptance criteria for weld acceptance is presented describing how this scheme provides improved robustness compared to the traditional flow-diagram standards.

Ultrasonic Non-destructive Prediction of Spot Welding Shear Strength

NASA Astrophysics Data System (ADS)

Himawan, R.; Haryanto, M.; Subekti, R. M.; Sunaryo, G. R.

2018-02-01

To enhance a corrosion resistant of ferritic steel in reactor pressure vessel, stainless steel was used as a cladding. Bonding process between these two steels may result a inhomogenity either sub-clad crack or un-joined part. To ensure the integrity, effective inspection method is needed for this purpose. Therefore, in this study, an experiment of ultrasonic test for inspection of two bonding plate was performed. The objective of this study is to develop an effective method in predicting the shear fracture load of the join. For simplicity, these joined was modelled with two plate of stainless steel with spot welding. Ultrasonic tests were performed using contact method with 5 MHz in frequency and 10 mm in diameter of transducer. Amplitude of reflected wave from intermediate layer was used as a quantitative parameter. A set of experiment results show that shear fracture load has a linear correlation with amplitude of reflected wave. Besides, amplitude of reflected wave also has relation with nugget diameter. It could be concluded that ultrasonic contact method could be applied in predicting a shear fracture load.

Non-Destructive Inspection of Impact Damage in Composite Aircraft Panels by Ultrasonic Guided Waves and Statistical Processing

PubMed Central

Capriotti, Margherita; Kim, Hyungsuk E.; Lanza di Scalea, Francesco; Kim, Hyonny

2017-01-01

This paper discusses a non-destructive evaluation (NDE) technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI) from ground service equipment (GSE), such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers. PMID:28772976

In-Service Monitoring of Steam Pipe Systems at High Temperatures

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph; Lih, Shyh-Shiuh; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Scott, James S.; Blosiu, Julian O.; Widholm, Scott E.

2011-01-01

An effective, in-service health monitoring system is needed to track water condensation in real time through the walls of steam pipes. The system is required to measure the height of the condensed water from outside the pipe, while operating at temperatures that are as high as 250 C. The system needs to account for the effects of water flow and cavitation. In addition, it is desired that the system does not require perforating the pipes and thereby reducing the structural integrity. Generally, steam pipes are used as part of the district heating system carrying steam from central power stations under the streets to heat, cool, or supply power to high-rise buildings and businesses. This system uses ultrasonic waves in pulse-echo and acquires reflected signal data. Via autocorrelation, it determines the water height while eliminating the effect of noise and multiple reflections from the wall of the pipe. The system performs nondestructive monitoring through the walls of steam pipes, and automatically measures the height of condensed water while operating at the high-temperature conditions of 250 C. For this purpose, the ultrasonic pulse-echo method is used where the time-of-flight of the wave reflections inside the water are measured, and it is multiplied by the wave velocity to determine the height. The pulse-echo test consists of emitting ultrasonic wave pulses from a piezoelectric transducer and receiving the reflections from the top and bottom of the condensed water. A single transducer is used as a transmitter as well as the receiver of the ultrasonic waves. To obtain high resolution, a broadband transducer is used and the frequency can be in the range of 2.25 to 10 MHz, providing sharp pulses in the time domain allowing for higher resolution in identifying the individual reflections.

Survey of Non-Destructive Tire Inspection Techniques

DOT National Transportation Integrated Search

1971-07-01

The status of several promising methods for non-destructive tire inspection is surveyed with the conclusion that radiographic, infrared, holographic and ultrasonic techniques warrant further evaluation. A program plan is outlined to correlate non-des...

Methodology to identify risk-significant components for inservice inspection and testing

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

Anderson, M.T.; Hartley, R.S.; Jones, J.L. Jr.

1992-08-01

Periodic inspection and testing of vital system components should be performed to ensure the safe and reliable operation of Department of Energy (DOE) nuclear processing facilities. Probabilistic techniques may be used to help identify and rank components by their relative risk. A risk-based ranking would allow varied DOE sites to implement inspection and testing programs in an effective and cost-efficient manner. This report describes a methodology that can be used to rank components, while addressing multiple risk issues.

Ultrasonic-Based Nondestructive Evaluation Methods for Wood: A Primer and Historical Review

Treesearch

Adam C. Senalik; Greg Schueneman; Robert J. Ross

2014-01-01

The authors conducted a review of ultrasonic testing and evaluation of wood and wood products, starting with a description of basic ultrasonic inspection setups and commonly used equations. The literature review primarily covered wood research presented between 1965 and 2013 in the Proceedings of the Nondestructive Testing of Wood Symposiums. A table that lists the...

Feature extraction for ultrasonic sensor based defect detection in ceramic components

NASA Astrophysics Data System (ADS)

Kesharaju, Manasa; Nagarajah, Romesh

2014-02-01

High density silicon carbide materials are commonly used as the ceramic element of hard armour inserts used in traditional body armour systems to reduce their weight, while providing improved hardness, strength and elastic response to stress. Currently, armour ceramic tiles are inspected visually offline using an X-ray technique that is time consuming and very expensive. In addition, from X-rays multiple defects are also misinterpreted as single defects. Therefore, to address these problems the ultrasonic non-destructive approach is being investigated. Ultrasound based inspection would be far more cost effective and reliable as the methodology is applicable for on-line quality control including implementation of accept/reject criteria. This paper describes a recently developed methodology to detect, locate and classify various manufacturing defects in ceramic tiles using sub band coding of ultrasonic test signals. The wavelet transform is applied to the ultrasonic signal and wavelet coefficients in the different frequency bands are extracted and used as input features to an artificial neural network (ANN) for purposes of signal classification. Two different classifiers, using artificial neural networks (supervised) and clustering (un-supervised) are supplied with features selected using Principal Component Analysis(PCA) and their classification performance compared. This investigation establishes experimentally that Principal Component Analysis(PCA) can be effectively used as a feature selection method that provides superior results for classifying various defects in the context of ultrasonic inspection in comparison with the X-ray technique.

Advanced ultrasonic techniques for nondestructive testing of austenitic and dissimilar welds in nuclear facilities

NASA Astrophysics Data System (ADS)

Juengert, Anne; Dugan, Sandra; Homann, Tobias; Mitzscherling, Steffen; Prager, Jens; Pudovikov, Sergey; Schwender, Thomas

2018-04-01

Austenitic stainless steel welds as well as dissimilar metal welds with nickel alloy filler material, used in safety relevant parts of nuclear power plants, still challenge the ultrasonic inspection. The weld material forms large oriented grains that lead, on the one hand, to high sound scattering and, on the other hand, to inhomogeneity and to the acoustic anisotropy of the weld structure. The ultrasonic wave fronts do not propagate linearly, as in ferritic weld joints, but along the curves, which depend on the specific grain structure of the weld. Due to the influence of these phenomena, it is difficult to analyze the inspection results and to classify the ultrasonic indications, which could be both from the weld geometry and from the material defects. A correct flaw sizing is not possible. In an ongoing research project, different techniques to improve the reliability of ultrasonic testing at these kinds of welds are investigated. In a first step (in the previous research project) two ultrasonic inspection techniques were developed and validated on plane test specimens with artificial and realistic flaws. In the ongoing project, these techniques are applied to circumferential pipe welds with longitudinal and transverse flaws. The technique developed at the Federal Institute for Materials Research and Testing (BAM) in Germany uses a combination of ray tracing and synthetic aperture focusing technique (SAFT). To investigate the unknown grain structure, the velocity distribution of weld-transmitting ultrasound waves is measured and used to model the weld by ray tracing. The second technique, developed at the Fraunhofer Institute for Nondestructive Testing (IZFP) in Germany, uses Sampling Phased Array (Full Matrix Capture) combined with the reverse phase matching (RPM) and the gradient elastic constant descent algorithm (GECDM). This inspection method is able to estimate the elastic constants of the columnar grains in the weld and offers an improvement of the

Optical surface contouring for non-destructive inspection of turbomachinery

NASA Astrophysics Data System (ADS)

Modarress, Dariush; Schaack, David F.

1994-03-01

Detection of stress cracks and other surface defects during maintenance and in-service inspection of propulsion system components, including turbine blades and combustion compartments, is presently performed visually. There is a need for a non-contact, miniaturized, and fully fieldable instrument that may be used as an automated inspection tool for inspection of aircraft engines. During this SBIR Phase 1 program, the feasibility of a ruggedized optical probe for automatic and nondestructive inspection of complex shaped objects will be established. Through a careful analysis of the measurement requirements, geometrical and optical constraints, and consideration of issues such as manufacturability, compactness, simplicity, and cost, one or more conceptual optical designs will be developed. The proposed concept will be further developed and a prototype will be fabricated during Phase 2.

Optical surface contouring for non-destructive inspection of turbomachinery

NASA Technical Reports Server (NTRS)

Modarress, Dariush; Schaack, David F.

1994-01-01

Detection of stress cracks and other surface defects during maintenance and in-service inspection of propulsion system components, including turbine blades and combustion compartments, is presently performed visually. There is a need for a non-contact, miniaturized, and fully fieldable instrument that may be used as an automated inspection tool for inspection of aircraft engines. During this SBIR Phase 1 program, the feasibility of a ruggedized optical probe for automatic and nondestructive inspection of complex shaped objects will be established. Through a careful analysis of the measurement requirements, geometrical and optical constraints, and consideration of issues such as manufacturability, compactness, simplicity, and cost, one or more conceptual optical designs will be developed. The proposed concept will be further developed and a prototype will be fabricated during Phase 2.

Rapid Inspection of Aerospace Structures - Is It Autonomous Yet?

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph; Backes, Paul; Joffe, Benjamin

1996-01-01

The trend to increase the usage of aging aircraft added a great deal of urgency to the ongoing need for low-cost, rapid, simple-to-operate, reliable and efficient NDE methods for detection and characterization of flaws in aircraft structures. In many cases, the problem of inspection is complex due to the limitation of current technology and the need to disassemble aircraft structures and testing them in lab conditions. To overcome these limitations, reliable field inspection tools are being developed for rapid NDE of large and complex-shape structures, that can operate at harsh, hostal and remote conditions with minimum human interface. In recent years, to address the need for rapid inspection in field conditions, numerous portable scanners were developed using NDE methods, including ultrasonics, shearography, thermography. This paper is written with emphasis on ultrasonic NDE scanners, their evolution and the expected direction of growth.

Flight-service program for advanced composite rudders on transport aircraft

NASA Technical Reports Server (NTRS)

1979-01-01

Flight service experience and in-service inspection results are reported for DC-10 graphite composite rudders during the third year of airline service. Test results and status are also reported for ground-based and airborne graphite-epoxy specimens with three different epoxy resin systems to obtain moisture absorption data. Twenty graphite composite rudders were produced, nine of which were installed on commercial aircraft during the past three years. The rudders collectively accumulated 75,863 flight hours. The high time rudder accumulated 12,740 flight hours in slightly over 36 months. The graphite composite rudders were inspected visually at approximately 1000 flight hour intervals and ultrasonically at approximately 3000 flight hour intervals in accordance with in-service inspection plans. All rudders were judged acceptable for continued service as a result of these inspections. Composite moisture absorption data on small specimens, both ground-based and carried aboard three flight-service aircraft, are given. The specimens include Thornel 300 fibers in Narmco 5208 and 5209 resin systems, and Type AS fibers in the Hercules 3501-6 resin system.

Deep sub-wavelength ultrasonic imaging

NASA Astrophysics Data System (ADS)

Amireddy, Kiran Kumar; Balasubramaniam, Krishnan; Rajagopal, Prabhu

2018-04-01

There is much interest in improving the resolution of ultrasonic inspection, which suffers from large wavelengths typically in the range of millimeters, due to low value of speed of sound in solid media. The authors are interested in achieving this through holey structured metamaterial lenses, and have recently demonstrated an experimental subwavelength resolution of λ/25. However the previous work was in through-transmission mode with reception using Laser Doppler Vibrometer (LDV), which may not be suitable for practical applications. This paper discusses the use of optimized holey structured metalens to achieve a deep sub-wavelength imaging up to λ/18 in through-transmission mode, but using commercially available piezoelectric ultrasonic transducers for both generation and reception of ultrasound.

Device for inspecting vessel surfaces

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

Appel, D.K.

1995-12-12

A portable, remotely-controlled inspection crawler is described for use along the walls of tanks, vessels, piping and the like. The crawler can be configured to use a vacuum chamber for supporting itself on the inspected surface by suction or a plurality of magnetic wheels for moving the crawler along the inspected surface. The crawler is adapted to be equipped with an ultrasonic probe for mapping the structural integrity or other characteristics of the surface being inspected. Navigation of the crawler is achieved by triangulation techniques between a signal transmitter on the crawler and a pair of microphones attached to amore » fixed, remote location, such as the crawler`s deployment unit. The necessary communications are established between the crawler and computers external to the inspection environment for position control and storage and/or monitoring of data acquisition. 5 figs.« less

Quality Inservice Education: Final Report of the National Inservice Network, 1978-1981.

ERIC Educational Resources Information Center

Burrello, Leonard C.; And Others

The document comprises the final report of the National Inservice Network (NIN), a program to describe and distribute regular education inservice (REGI) project abstracts, products, and lessons aimed at more effectively working with handicapped students. Initial sections contain an executive summary and an overview explaining the NIN as a…

Numerical and Experimental Characterization of a Composite Secondary Bonded Adhesive Lap Joint Using the Ultrasonics method

NASA Astrophysics Data System (ADS)

Kumar, M. R.; Ghosh, A.; Karuppannan, D.

2018-05-01

The construction of aircraft using advanced composites have become very popular during the past two decades, in which many innovative manufacturing processes, such as cocuring, cobonding, and secondary bonding processes, have been adopted. The secondary bonding process has become less popular than the other two ones because of nonavailability of process database and certification issues. In this article, an attempt is made to classify the quality of bonding using nondestructive ultrasonic inspection methods. Specimens were prepared and tested using the nondestructive ultrasonic Through Transmission (TT), Pulse Echo (PE), and air coupled guided wave techniques. It is concluded that the ultrasonic pulse echo technique is the best one for inspecting composite secondary bonded adhesive joints.

A study on laser-based ultrasonic technique by the use of guided wave tomographic imaging

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

Park, Junpil, E-mail: jpp@pusan.ac.kr; Lim, Juyoung, E-mail: jpp@pusan.ac.kr; Cho, Younho

2015-03-31

Guided wave tests are impractical for investigating specimens with limited accessibility and coarse surfaces or geometrically complicated features. A non-contact setup with a laser ultrasonic transmitter and receiver is the classic attractive for guided wave inspection. The present work was done to develop a non-contact guided-wave tomography technique by laser ultrasonic technique in a plate-like structure. A method for Lam wave generation and detection in an aluminum plate with a pulse laser ultrasonic transmitter and a Michelson interferometer receiver has been developed. In the images obtained by laser scanning, the defect shape and area showed good agreement with the actualmore » defect. The proposed approach can be used as a non-contact-based online inspection and monitoring technique.« less

Study of ultrasonic sensor that is effective for all direction using an electromagnetic force

NASA Astrophysics Data System (ADS)

Iwaya, Kazuki; Murayama, Riichi; Hirayama, Takahiro

2015-03-01

Non-destructive inspection using ultrasonic sensors is widely utilized to guarantee the safety of large structures. However, there is the problem that it will take a very long time to complete. Therefore, it was decided to develop a sensor capable of testing a wide range of structures at a high inspection speed. The ultrasonic wave that the ultrasonic sensor can generate must be equally emitted in any direction and the ultrasonic wave returned from any direction be detected. To attain this objective, an electromagnetic acoustic transducer (EMAT) consisting of a circular-shaped magnet and an electric induction coil (EM) has been developed, because it is impossible to fabricate such a special ultrasonic sensor using a commercial-type ultrasonic sensor with a piezoelectric element, and it is convenient to automatically scan over the surface of the structure. First, the detail specifications of the new ultrasonic sensor have been determined by changing many of the parameters, for example, the impedance and the size of the EM coil, the size of the magnet, etc. The performance of the new sensor was then tested under different conditions. Based on the results of the experimental tests, it was demonstrated that the new sensor could generate ultrasonic waves in any direction and detect them from any direction. However, the performance was not high enough to apply the new sensor to a real structure. The new sensor has been improved to increase the performance by adding a new concept.

System Model for MEMS based Laser Ultrasonic Receiver

NASA Technical Reports Server (NTRS)

Wilson, William C.

2002-01-01

A need has been identified for more advanced nondestructive Evaluation technologies for assuring the integrity of airframe structures, wiring, etc. Laser ultrasonic inspection instruments have been shown to detect flaws in structures. However, these instruments are generally too bulky to be used in the confined spaces that are typical of aerospace vehicles. Microsystems technology is one key to reducing the size of current instruments and enabling increased inspection coverage in areas that were previously inaccessible due to instrument size and weight. This paper investigates the system modeling of a Micro OptoElectroMechanical System (MOEMS) based laser ultrasonic receiver. The system model is constructed in software using MATLAB s dynamical simulator, Simulink. The optical components are modeled using geometrical matrix methods and include some image processing. The system model includes a test bench which simulates input stimuli and models the behavior of the material under test.

Robotic Welding and Inspection System

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

H. B. Smartt; D. P. Pace; E. D. Larsen

2008-06-01

This paper presents a robotic system for GTA welding of lids on cylindrical vessels. The system consists of an articulated robot arm, a rotating positioner, end effectors for welding, grinding, ultrasonic and eddy current inspection. Features include weld viewing cameras, modular software, and text-based procedural files for process and motion trajectories.

Development of a High Performance Acousto-ultrasonic Scan System

NASA Technical Reports Server (NTRS)

Roth, D. J.; Martin, R. E.; Harmon, L. M.; Gyekenyesi, A. L.; Kautz, H. E.

2002-01-01

Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation (NDE) technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition/distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods such as ultrasonic c-scan, x-ray radiography, and thermographic inspection that tend to be used primarily for discrete flaw detection. Through its history, AU has been used to inspect polymer matrix composite, metal matrix composite, ceramic matrix composite, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. In this paper, a review of essential AU technology is given. Additionally, the basic hardware and software configuration, and preliminary results with the system, are described.

Non-contact ultrasonic defect imaging in composites

NASA Astrophysics Data System (ADS)

Tenoudji, F. Cohen; Citerne, J. M.; Dutilleul, H.; Busquet, D.

2016-02-01

In the situations where conventional NDT ultrasonic techniques using immersion of the part under inspection or its contact with the transducers cannot be used, in-air investigation presents an alternative. The huge impedance mismatch between the part material and air (transmission loss in the order of 80 dB for a thin metallic plate) induces having to deal very small signals and unfavorable signal to noise ratios. The approach adopted here is the use of the crack of a spark generated by an induction coil as a sound source and an electrostatic polyethylene membrane microphone as a receiver [1]. The advantage of this source is that the spark power is high (several kilowatts) and its power is directly coupled to air during the energy release. In some difficult situations, an elliptical mirror is used to concentrate the sound beam power on the surface of the part [2,3]. Stability and reproducibility of the sound generated by the spark, which are a necessity in order to perform quantitative evaluations, are achieved in our experiment. This permits also an increase of the signal to noise ratio by signal accumulation. The sound pulse duration of few microseconds allows operating in pulse echo in some circumstances. The bandwidth of the source is large, of several hundred of kilohertz, and that of the microphone above 100 kHz allow the flexibility to address different kinds of materials. The technique allows an easy, in-air, non contact, inspection of structural composite parts, with pulse waves, with an excellent signal to noise ratio. An X-Y ultrasonic scanning ultrasonic system for material inspection using this technique has been realized. Results obtained in transmission and reflection are presented. Defects in carbon composite plates and in honeycomb are imaged in transmission Echographic measurements show that defect detection can be performed in thin plates using Lamb waves propagation when only one sided inspection of the part is possible.

On Limitations of the Ultrasonic Characterization of Pieces Manufactured with Highly Attenuating Materials

NASA Astrophysics Data System (ADS)

Ramos, A.; Moreno, E.; Rubio, B.; Calas, H.; Galarza, N.; Rubio, J.; Diez, L.; Castellanos, L.; Gómez, T.

Some technical aspects of two Spanish cooperation projects, funded by DPI and Innpacto Programs of the R&D National Plan, are discussed. The objective is to analyze the common belief about than the ultrasonic testing in MHz range is not a tool utilizable to detect internal flaws in highly attenuating pieces made of coarse-grained steel. In fact high-strength steels, used in some safe industrial infrastructures of energy & transport sectors, are difficult to be inspected using the conventional "state of the art" in ultrasonic technology, due to their internal microstructures are very attenuating and coarse-grained. It is studied if this inspection difficulty could be overcome by finding intense interrogating pulses and advanced signal processing of the acquired echoes. A possible solution would depend on drastically improving signal-to-noise-ratios, by applying new advances on: ultrasonic transduction, HV electronics for intense pulsed driving of the testing probes, and an "ad-hoc" digital processing or focusing of the received noisy signals, in function of each material to be inspected. To attain this challenging aim on robust steel pieces would open the possibility of obtaining improvements in inspecting critical industrial components made of highly attenuating & dispersive materials, as new composites in aeronautic and motorway bridges, or new metallic alloys in nuclear area, where additional testing limitations often appear.

Preliminary design of high temperature ultrasonic transducers for liquid sodium environments

NASA Astrophysics Data System (ADS)

Prowant, M. S.; Dib, G.; Qiao, H.; Good, M. S.; Larche, M. R.; Sexton, S. S.; Ramuhalli, P.

2018-04-01

Advanced reactor concepts include fast reactors (including sodium-cooled fast reactors), gas-cooled reactors, and molten-salt reactors. Common to these concepts is a higher operating temperature (when compared to light-water-cooled reactors), and the proposed use of new alloys with which there is limited operational experience. Concerns about new degradation mechanisms, such as high-temperature creep and creep fatigue, that are not encountered in the light-water fleet and longer operating cycles between refueling intervals indicate the need for condition monitoring technology. Specific needs in this context include periodic in-service inspection technology for the detection and sizing of cracking, as well as technologies for continuous monitoring of components using in situ probes. This paper will discuss research on the development and evaluation of high temperature (>550°C; >1022°F) ultrasonic probes that can be used for continuous monitoring of components. The focus of this work is on probes that are compatible with a liquid sodium-cooled reactor environment, where the core outlet temperatures can reach 550°C (1022°F). Modeling to assess sensitivity of various sensor configurations and experimental evaluation have pointed to a preferred design and concept of operations for these probes. This paper will describe these studies and ongoing work to fabricate and fully evaluate survivability and sensor performance over extended periods at operational temperatures.

Inspection of aircraft fastener holes using a conically shaped multi-element phased array probe

NASA Astrophysics Data System (ADS)

Selman, J. J.; Miller, J. T.; Moles, M. D. C.; Dupuis, O.; Herzog, P. G.

2002-05-01

A novel inspection technique is described using phased ultrasonic arrays to detect faying surface cracks in the first layer around the base of a fastener hole with fasteners installed. A unique phased array probe incorporates a matrix of ultrasonic elements arranged in a conical configuration encircling the fastener head. This arrangement permits deflection of the ultrasonic beam in three dimensions, and adapts to different hole diameters and skin thickness. Full circumferential scans are performed using a pre-programmed sequence of phased array focal laws. The inspection method uses pulse-echo at a variety of angles incident on the crack to thoroughly cover the fastener hole and surrounding area, and is designed to detect cracks as small as 0.030″ in length.

Simulation of ultrasonic arrays for industrial and civil engineering applications including validation

NASA Astrophysics Data System (ADS)

Spies, M.; Rieder, H.; Orth, Th.; Maack, S.

2012-05-01

In this contribution we address the beam field simulation of 2D ultrasonic arrays using the Generalized Point Source Synthesis technique. Aiming at the inspection of cylindrical components (e.g. pipes) the influence of concave and convex surface curvatures, respectively, has been evaluated for a commercial probe. We have compared these results with those obtained using a commercial simulation tool. In civil engineering, the ultrasonic inspection of highly attenuating concrete structures has been advanced by the development of dry contact point transducers, mainly applied in array arrangements. Our respective simulations for a widely used commercial probe are validated using experimental results acquired on concrete half-spheres with diameters from 200 mm up to 650 mm.

Microstructural and Defect Characterization in Ceramic Composites Using an Ultrasonic Guided Wave Scan System

NASA Technical Reports Server (NTRS)

Roth, D. J.; Cosgriff, L. M.; Martin, R. E.; Verrilli, M. J.; Bhatt, R. T.

2003-01-01

In this study, an ultrasonic guided wave scan system was used to characterize various microstructural and flaw conditions in two types of ceramic matrix composites, SiC/SiC and C/SiC. Rather than attempting to isolate specific lamb wave modes to use for characterization (as is desired for many types of guided wave inspection problems), the guided wave scan system utilizes the total (multi-mode) ultrasonic response in its inspection analysis. Several time and frequency-domain parameters are calculated from the ultrasonic guided wave signal at each scan location to form images. Microstructural and defect conditions examined include delamination, density variation, cracking, and pre/ post-infiltration. Results are compared with thermographic imaging methods. Although the guided wave technique is commonly used so scanning can be eliminated, applying the technique in the scanning mode allows a more precise characterization of defect conditions.

Nondestructive inspection of a composite missile launcher

NASA Astrophysics Data System (ADS)

Ley, O.; Chung, S.; Butera, M.; Valatka, T.; Triplett, M. H.; Godinez, V.

2012-05-01

Lighter weight alternatives are being sought to replace metallic components currently used in high performance aviation and missile systems. Benefits of lightweight, high strength carbon fiber reinforced composites in missile launchers and rocket motor cases include improved fuel economy, increased flight times, enhanced lethality and/or increased velocity. In this work, various nondestructive inspection techniques are investigated for the damage assessment of a composite missile launcher system for use in U.S. Army attack helicopters. The launcher system, which includes rails and a hardback, can be subject to impact damage from accidental tool drops, routine operation, and/or ballistic threats. The composite hardback and the launch rails both have complex geometries that can challenge the inspection process. Scanning techniques such as line scanning thermography, ultrasonic, and acousto-ultrasonics will be used and compared to determine damage detection accuracy, reliability, and efficiency. Results will also be compared with visual observations to determine if there is a correlation. The goal is to establish an inspection method that quickly and accurately assesses damage extent in order to minimize service time and return the missile system back into the field [1].

A novel serrated columnar phased array ultrasonic transducer

NASA Astrophysics Data System (ADS)

Zou, Cheng; Sun, Zhenguo; Cai, Dong; Song, Hongwei; Chen, Qiang

2016-02-01

Traditionally, wedges are required to generate transverse waves in a solid specimen and mechanical rotation device is needed for interrogation of a specimen with a hollow bore, such as high speed railway locomotive axles, turbine rotors, etc. In order to eliminate the mechanical rotation process, a novel array pattern of phased array ultrasonic transducers named as serrated columnar phased array ultrasonic transducer (SCPAUT) is designed. The elementary transducers are planar rectangular, located on the outside surface of a cylinder. This layout is aimed to generate electrically rotating transverse waveforms so as to inspect the longitudinal cracks on the outside surface of a specimen which has a hollow bore at the center, such as the high speed railway locomotive axles. The general geometry of the SCPAUT and the inspection system are illustrated. A FEM model and mockup experiment has been carried out. The experiment results are in good agreement with the FEM simulation results.

High resolution ultrasonic spectroscopy system for nondestructive evaluation

NASA Technical Reports Server (NTRS)

Chen, C. H.

1991-01-01

With increased demand for high resolution ultrasonic evaluation, computer based systems or work stations become essential. The ultrasonic spectroscopy method of nondestructive evaluation (NDE) was used to develop a high resolution ultrasonic inspection system supported by modern signal processing, pattern recognition, and neural network technologies. The basic system which was completed consists of a 386/20 MHz PC (IBM AT compatible), a pulser/receiver, a digital oscilloscope with serial and parallel communications to the computer, an immersion tank with motor control of X-Y axis movement, and the supporting software package, IUNDE, for interactive ultrasonic evaluation. Although the hardware components are commercially available, the software development is entirely original. By integrating signal processing, pattern recognition, maximum entropy spectral analysis, and artificial neural network functions into the system, many NDE tasks can be performed. The high resolution graphics capability provides visualization of complex NDE problems. The phase 3 efforts involve intensive marketing of the software package and collaborative work with industrial sectors.

Novel approach of wavelet analysis for nonlinear ultrasonic measurements and fatigue assessment of jet engine components

NASA Astrophysics Data System (ADS)

Bunget, Gheorghe; Tilmon, Brevin; Yee, Andrew; Stewart, Dylan; Rogers, James; Webster, Matthew; Farinholt, Kevin; Friedersdorf, Fritz; Pepi, Marc; Ghoshal, Anindya

2018-04-01

Widespread damage in aging aircraft is becoming an increasing concern as both civil and military fleet operators are extending the service lifetime of their aircraft. Metallic components undergoing variable cyclic loadings eventually fatigue and form dislocations as precursors to ultimate failure. In order to characterize the progression of fatigue damage precursors (DP), the acoustic nonlinearity parameter is measured as the primary indicator. However, using proven standard ultrasonic technology for nonlinear measurements presents limitations for settings outside of the laboratory environment. This paper presents an approach for ultrasonic inspection through automated immersion scanning of hot section engine components where mature ultrasonic technology is used during periodic inspections. Nonlinear ultrasonic measurements were analyzed using wavelet analysis to extract multiple harmonics from the received signals. Measurements indicated strong correlations of nonlinearity coefficients and levels of fatigue in aluminum and Ni-based superalloys. This novel wavelet cross-correlation (WCC) algorithm is a potential technique to scan for fatigue damage precursors and identify critical locations for remaining life prediction.

Automated inspection of solder joints for surface mount technology

NASA Technical Reports Server (NTRS)

Savage, Robert M.; Park, Hyun Soo; Fan, Mark S.

1993-01-01

Researchers at NASA/GSFC evaluated various automated inspection systems (AIS) technologies using test boards with known defects in surface mount solder joints. These boards were complex and included almost every type of surface mount device typical of critical assemblies used for space flight applications: X-ray radiography; X-ray laminography; Ultrasonic Imaging; Optical Imaging; Laser Imaging; and Infrared Inspection. Vendors, representative of the different technologies, inspected the test boards with their particular machine. The results of the evaluation showed limitations of AIS. Furthermore, none of the AIS technologies evaluated proved to meet all of the inspection criteria for use in high-reliability applications. It was found that certain inspection systems could supplement but not replace manual inspection for low-volume, high-reliability, surface mount solder joints.

Robotic NDE inspection of advanced solid rocket motor casings

NASA Technical Reports Server (NTRS)

Mcneelege, Glenn E.; Sarantos, Chris

1994-01-01

The Advanced Solid Rocket Motor program determined the need to inspect ASRM forgings and segments for potentially catastrophic defects. To minimize costs, an automated eddy current inspection system was designed and manufactured for inspection of ASRM forgings in the initial phases of production. This system utilizes custom manipulators and motion control algorithms and integrated six channel eddy current data acquisition and analysis hardware and software. Total system integration is through a personal computer based workcell controller. Segment inspection demands the use of a gantry robot for the EMAT/ET inspection system. The EMAT/ET system utilized similar mechanical compliancy and software logic to accommodate complex part geometries. EMAT provides volumetric inspection capability while eddy current is limited to surface and near surface inspection. Each aspect of the systems are applicable to other industries, such as, inspection of pressure vessels, weld inspection, and traditional ultrasonic inspection applications.

ORCHID - a computer simulation of the reliability of an NDE inspection system

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

Moles, M.D.C.

1987-03-01

CANDU pressurized heavy water reactors contain several hundred horizontally-mounted zirconium alloy pressure tubes. Following a pressure tube failure, a pressure tube inspection system called CIGARette was rapidly designed, manufactured and put in operation. Defects called hydride blisters were found to be the cause of the failure, and were detected using a combination of eddy current and ultrasonic scans. A number of improvements were made to CIGARette during the inspection period. The ORCHID computer program models the operation of the delivery system, eddy current and ultrasonic systems by imitating the on-reactor decision-making procedure. ORCHID predicts that during the early stage ofmore » development, less than one blistered tube in three would be detected, while less than one in two would be detected in the middle development stage. However, ORCHID predicts that during the late development stage, probability of detection will be over 90%, primarily due to the inclusion of axial ultrasonic scans (a procedural modification). Rotational and axial slip could severely reduce probability of detection. Comparison of CIGARette's inspection data with ORCHID's predictions indicate that the latter are compatible with the actual inspection results, through the numbers are small and data uncertain. It should be emphasized that the CIGARette system has been essentially replaced with the much more reliable CIGAR system.« less

In-service inspection of steam turbine blades without disassembly

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

Reinhart, E.R.

1987-01-01

Loss of utility plant availability as a result of failure-causing cracks in steam turbine blades makes early detection of this problem critical. An Electric Power Research Institute survey, conducted as part of project RP 1266-24, indicated that 72% of turbine blade failures in fossil power plants occur in low-pressure (LP) turbines with half of all blade failures occurring in the last two blade stages (L-0 and L-1 rows). Failures are generally associated with blade tailing edges and root areas. Project RP 1266-24 also found that 79% of the blade problems in LP turbines were cracks. A turbine design of particularmore » concern has been the Westinghouse Building Block (B.B.) 73. Reinhart and Associates has successfully inspected seven in-place B.B. 73 units for six utilities during the past 3 yr, as well as several disassembled turbines of other manufacturers and designs. These examinations consisted of visual and eddy-current examinations of the blade roots and trailing edges. The in-place inspections were performed using prototype manipulation devices to gain access to the blades through the hand holes. The only disassembly required to gain access for the examinations was the removal of the man-way covers on the main shell and the hand-hole covers on the outer cylinder covering the L-0 and L-1 blade rows.« less

Electromagnetic Acoustic Transducers for Robotic Nondestructive Inspection in Harsh Environments

PubMed Central

Choi, Sungho; Cho, Hwanjeong; Lindsey, Matthew S.; Lissenden, Cliff J.

2018-01-01

Elevated temperature, gamma radiation, and geometric constraints inside dry storage casks for spent nuclear fuel represent a harsh environment for nondestructive inspection of the cask and require that the inspection be conducted with a robotic system. Electromagnetic acoustic transducers (EMATs) using non-contact ultrasonic transduction based on the Lorentz force to excite/receive ultrasonic waves are suited for use in the robotic inspection. Periodic permanent magnet EMATs that actuate/receive shear horizontal guided waves are developed for application to robotic nondestructive inspection of stress corrosion cracks in the heat affected zone of welds in stainless steel dry storage canisters. The EMAT’s components are carefully selected in consideration of the inspection environment, and tested under elevated temperature and gamma radiation doses up to 177 °C and 5920 krad, respectively, to evaluate the performance of the EMATs under realistic environmental conditions. The effect of gamma radiation is minimal, but the EMAT’s performance is affected by temperatures above 121 °C due to the low Curie temperature of the magnets. Different magnets are needed to operate at 177 °C. The EMAT’s capability to detect notches is also evaluated from B-scan measurements on 304 stainless steel welded plate containing surface-breaking notches. PMID:29324721

Electromagnetic Acoustic Transducers for Robotic Nondestructive Inspection in Harsh Environments.

PubMed

Choi, Sungho; Cho, Hwanjeong; Lindsey, Matthew S; Lissenden, Cliff J

2018-01-11

Elevated temperature, gamma radiation, and geometric constraints inside dry storage casks for spent nuclear fuel represent a harsh environment for nondestructive inspection of the cask and require that the inspection be conducted with a robotic system. Electromagnetic acoustic transducers (EMATs) using non-contact ultrasonic transduction based on the Lorentz force to excite/receive ultrasonic waves are suited for use in the robotic inspection. Periodic permanent magnet EMATs that actuate/receive shear horizontal guided waves are developed for application to robotic nondestructive inspection of stress corrosion cracks in the heat affected zone of welds in stainless steel dry storage canisters. The EMAT's components are carefully selected in consideration of the inspection environment, and tested under elevated temperature and gamma radiation doses up to 177 °C and 5920 krad, respectively, to evaluate the performance of the EMATs under realistic environmental conditions. The effect of gamma radiation is minimal, but the EMAT's performance is affected by temperatures above 121 °C due to the low Curie temperature of the magnets. Different magnets are needed to operate at 177 °C. The EMAT's capability to detect notches is also evaluated from B-scan measurements on 304 stainless steel welded plate containing surface-breaking notches.

A New High-Temperature Ultrasonic Transducer for Continuous Inspection.

PubMed

Amini, Mohammad Hossein; Sinclair, Anthony N; Coyle, Thomas W

2016-03-01

A novel design of piezoelectric ultrasonic transducer is introduced, suitable for operation at temperatures of up to 700 °C-800 °C. Lithium niobate single crystal is chosen as the piezoelectric element primarily due to the high Curie temperature of 1200 °C. A backing element based on a porous ceramic is designed for which the pore volume fraction and average pore diameter in the ceramic matrix can be controlled in the manufacturing process; this enables the acoustic impedance and attenuation to be selected to match their optimal values as predicted by a one-dimensional transducer model of the entire transducer. Porous zirconia is selected as the ceramic matrix material of the backing element to obtain an ultrasonic signal with center frequency of 2.7-3 MHz, and 3-dB bandwidth of 90%-95% at the targeted operating temperature. Acoustic coupling of the piezocrystal to the backing element and matching layer is investigated using commercially available high-temperature adhesives and brazing alloys. The performance of the transducer as a function of temperature is studied. Stable bonding and clear signals were obtained using an aluminum brazing alloy as the bonding agent.

Monitoring of freeze-thaw cycles in concrete using embedded sensors and ultrasonic imaging.

PubMed

Ranz, Javier; Aparicio, Sofía; Romero, Héctor; Casati, María Jesús; Molero, Miguel; González, Margarita

2014-01-29

This paper deals with the study of damage produced during freeze-thaw (F-T) cycles using two non-destructive measurement approaches-the first approach devoted to continuous monitoring using embedded sensors during the cycles, and the second one, performing ultrasonic imaging before and after the cycles. Both methodologies have been tested in two different types of concrete specimens, with and without air-entraining agents. Using the first measurement approach, the size and distribution of pores were estimated using a thermoporometrical model and continuous measurements of temperature and ultrasonic velocity along cycles. These estimates have been compared with the results obtained using mercury porosimetry testing. In the second approach, the damage due to F-T cycles has been evaluated by automated ultrasonic transmission and pulse-echo inspections made before and after the cycles. With these inspections the variations in the dimensions, velocity and attenuation caused by the accelerated F-T cycles were determined.

Monitoring of Freeze-Thaw Cycles in Concrete Using Embedded Sensors and Ultrasonic Imaging

PubMed Central

Ranz, Javier; Aparicio, Sofía; Romero, Héctor; Casati, María Jesús; Molero, Miguel; González, Margarita

2014-01-01

This paper deals with the study of damage produced during freeze-thaw (F-T) cycles using two non-destructive measurement approaches—the first approach devoted to continuous monitoring using embedded sensors during the cycles, and the second one, performing ultrasonic imaging before and after the cycles. Both methodologies have been tested in two different types of concrete specimens, with and without air-entraining agents. Using the first measurement approach, the size and distribution of pores were estimated using a thermoporometrical model and continuous measurements of temperature and ultrasonic velocity along cycles. These estimates have been compared with the results obtained using mercury porosimetry testing. In the second approach, the damage due to F-T cycles has been evaluated by automated ultrasonic transmission and pulse-echo inspections made before and after the cycles. With these inspections the variations in the dimensions, velocity and attenuation caused by the accelerated F-T cycles were determined. PMID:24481231

Quantitative Ultrasonic Evaluation of Mechanical Properties of Engineering Materials

NASA Technical Reports Server (NTRS)

Vary, A.

1978-01-01

Progress in the application of ultrasonic techniques to nondestructive measurement of mechanical strength of engineering materials is reviewed. A dormant concept in nondestructive evaluation (NDE) is invoked. The availability of ultrasonic methods that can be applied to actual parts to assess their potential susceptibility to failure under design conditions is discussed. It was shown that ultrasonic methods yield measurements of elastic moduli, microstructure, hardness, fracture toughness, tensile strength, yield strength, and shear strength for a wide range of materials (including many types of metals, ceramics, and fiber composites). It was also indicated that although most of these methods were shown feasible in laboratory studies, more work is needed before they can be used on actual parts in processing, assembly, inspection, and maintenance lines.

Steam generator tube inspection in Japan

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

Fukui, Shigetaka

1997-02-01

Steam generator tube inspection was first carried out in 1971 at Mihama Unit-1 that is first PWR plant in Japan, when the plant was brought into the first annual inspection. At that time, inspection was made on sampling basis, and only bobbin coil probe was used. After experiencing various kinds of tube degradations, inspection method was changed from sampling to all number of tubes, and various kinds of probes were used to get higher detectability of flaw. At present, it is required that all the tubes shall be inspected in their full length at each annual inspection using standard bobbinmore » coil probe, and some special probes for certain plants that have susceptibility of occurrence of flaw. Sleeve repaired portion is included in this inspection. As a result of analyses of eddy current testing data, all indications that have been evaluated to be 20% wall thickness or deeper shall be repaired by either plugging or sleeving, where flaw morphology is to be a wastage or wear. Other types of flaw such as IGA/SCC are not allowed to be left inservice when those indications are detected. These inspections are performed according to inspection procedures that are approved by regulatory authority. Actual inspections are witnessed by the Japan Power engineering and inspection corporation (JAPEIC)`s inspectors during data acquisition and analysis, and they issue inspection report to authority for review and approval. It is achieved high safety performance of steam generator through this method of inspections, however. some tube leakage problems were experienced in the past. To prevent recurrence of such events, government is conducting development and verification test program for new eddy current testing technology.« less

Assessment of Current Inservice Inspection and Leak Monitoring Practices for Detecting Materials Degradation in Light Water Reactors

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

Anderson, Michael T.; Simonen, Fredric A.; Muscara, Joseph

2016-09-01

An assessment was performed to determine the effectiveness of existing inservice inspection (ISI) and leak monitoring techniques, and recommend improvements, as necessary, to the programs as currently performed for light water reactor (LWR) components. Information from nuclear power plant (NPP) aging studies and from the U. S. Nuclear Regulatory Commission’s Generic Aging Lessons Learned (GALL) report (NUREG-1801) was used to identify components that have already experienced, or are expected to experience, degradation. This report provides a discussion of the key aspects and parameters that constitute an effective ISI program and a discussion of the basis and background against which themore » effectiveness of the ISI and leak monitoring programs for timely detection of degradation was evaluated. Tables based on the GALL components were used to systematically guide the process, and table columns were included that contained the ISI requirements and effectiveness assessment. The information in the tables was analyzed using histograms to reduce the data and help identify any trends. The analysis shows that the overall effectiveness of the ISI programs is very similar for both boiling water reactors (BWRs) and pressurized water reactors (PWRs). The evaluations conducted as part of this research showed that many ISI programs are not effective at detecting degradation before its extent reached 75% of the component wall thickness. This work should be considered as an assessment of NDE practices at this time; however, industry and regulatory activities are currently underway that will impact future effectiveness assessments. A number of actions have been identified to improve the current ISI programs so that degradation can be more reliably detected.« less

Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

NASA Technical Reports Server (NTRS)

Miller, James G.

1994-01-01

In this Progress Report, we describe our continuing research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the inspection and characterization of complex composite structures. We explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. As an initial step toward the application of linear array imaging technology to the interrogation of a wide range of complex composite structures, we present images obtained using an unmodified medical ultrasonic imaging system of two epoxy-bonded aluminum plate specimens, each with intentionally disbonded regions. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to assess whether these images can detect disbonded regions and provide information regarding the nature of the disbonded region. We present a description of a standoff/delay fixture which has been designed, constructed, and implemented on a Hewlett-Packard SONOS 1500 medical imaging system. This standoff/delay fixture, when attached to a 7.5 MHz linear array probe, greatly enhances our ability to interrogate flat plate specimens. The final section of this Progress Report describes a woven composite plate specimen that has been specially machined to include intentional flaws. This woven composite specimen will allow us to assess the feasibility of applying linear array imaging technology to the inspection and characterization of complex textile composite materials. We anticipate the results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology.

Recent advances in aerospace composite NDE

NASA Astrophysics Data System (ADS)

Georgeson, Gary E.

2002-06-01

As the aerospace industry continues to advance the design and use of composite structure, the NDE community faces the difficulties of trying to keep up. The challenges lie in manufacturing evaluation of the newest aerospace structures and materials and the in-service inspection and monitoring of damaged or aging composites. This paper provides examples of several promising NDI applications in the world of aerospace composites. Airborne (or non-contact) Ultrasonic Testing (UT) has been available for decades, but recently has generated new interest due to significant improvements in transducer design and low noise electronics. Boeing is developing inspection techniques for composite joints and core blankets using this technology. In-service inspection techniques for thick, multi-layer structures are also being advanced. One effective technique integrates the S-9 Sondicator, a traditional bond testing device, with Boeing's Mobile Automated Scanner (MAUS) platform. Composite patches have seen limited use on-aircraft, due, in part, to the difficulty of determining the quality of a bonded joint. A unique approach using Electronic Speckle Pattern Interferometry (ESPI) is showing promise as a bonded patch-inspection method. Other NDI techniques currently being developed for aerospace application are also briefly discussed.

Inspection design using 2D phased array, TFM and cueMAP software

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

McGilp, Ailidh; Dziewierz, Jerzy; Lardner, Tim

2014-02-18

A simulation suite, cueMAP, has been developed to facilitate the design of inspection processes and sparse 2D array configurations. At the core of cueMAP is a Total Focusing Method (TFM) imaging algorithm that enables computer assisted design of ultrasonic inspection scenarios, including the design of bespoke array configurations to match the inspection criteria. This in-house developed TFM code allows for interactive evaluation of image quality indicators of ultrasonic imaging performance when utilizing a 2D phased array working in FMC/TFM mode. The cueMAP software uses a series of TFM images to build a map of resolution, contrast and sensitivity of imagingmore » performance of a simulated reflector, swept across the inspection volume. The software takes into account probe properties, wedge or water standoff, and effects of specimen curvature. In the validation process of this new software package, two 2D arrays have been evaluated on 304n stainless steel samples, typical of the primary circuit in nuclear plants. Thick section samples have been inspected using a 1MHz 2D matrix array. Due to the processing efficiency of the software, the data collected from these array configurations has been used to investigate the influence sub-aperture operation on inspection performance.« less

Characterization of Developer Application Methods Used in Fluorescent Penetrant Inspection

NASA Astrophysics Data System (ADS)

Brasche, L. J. H.; Lopez, R.; Eisenmann, D.

2006-03-01

Fluorescent penetrant inspection (FPI) is the most widely used inspection method for aviation components seeing use for production as well as an inservice inspection applications. FPI is a multiple step process requiring attention to the process parameters for each step in order to enable a successful inspection. A multiyear program is underway to evaluate the most important factors affecting the performance of FPI, to determine whether existing industry specifications adequately address control of the process parameters, and to provide the needed engineering data to the public domain. The final step prior to the inspection is the application of developer with typical aviation inspections involving the use of dry powder (form d) usually applied using either a pressure wand or dust storm chamber. Results from several typical dust storm chambers and wand applications have shown less than optimal performance. Measurements of indication brightness and recording of the UVA image, and in some cases, formal probability of detection (POD) studies were used to assess the developer application methods. Key conclusions and initial recommendations are provided.

42 CFR 488.425 - Directed inservice training.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 5 2014-10-01 2014-10-01 false Directed inservice training. 488.425 Section 488... Compliance for Long-Term Care Facilities with Deficiencies § 488.425 Directed inservice training. (a) Required training. CMS or the State agency may require the staff of a facility to attend an inservice...

42 CFR 488.425 - Directed inservice training.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Directed inservice training. 488.425 Section 488... Compliance for Long-Term Care Facilities with Deficiencies § 488.425 Directed inservice training. (a) Required training. CMS or the State agency may require the staff of a facility to attend an inservice...

42 CFR 488.425 - Directed inservice training.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 5 2013-10-01 2013-10-01 false Directed inservice training. 488.425 Section 488... Compliance for Long-Term Care Facilities with Deficiencies § 488.425 Directed inservice training. (a) Required training. CMS or the State agency may require the staff of a facility to attend an inservice...

42 CFR 488.425 - Directed inservice training.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 5 2011-10-01 2011-10-01 false Directed inservice training. 488.425 Section 488... Compliance for Long-Term Care Facilities with Deficiencies § 488.425 Directed inservice training. (a) Required training. CMS or the State agency may require the staff of a facility to attend an inservice...

42 CFR 488.425 - Directed inservice training.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 5 2012-10-01 2012-10-01 false Directed inservice training. 488.425 Section 488... Compliance for Long-Term Care Facilities with Deficiencies § 488.425 Directed inservice training. (a) Required training. CMS or the State agency may require the staff of a facility to attend an inservice...

Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

NASA Technical Reports Server (NTRS)

Miller, James G.

1993-01-01

In this Progress Report, we describe our current research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of stitched composite materials and bonded aluminum plate specimens. One purpose of this investigation is to identify and characterize specific features of polar backscatter interrogation which enhance the ability of ultrasound to detect flaws in a stitched composite laminate. Another focus is to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize bonded aluminum lap joints. As an approach to implementing quantitative ultrasonic inspection methods to both of these materials, we focus on the physics that underlies the detection of flaws in such materials.

Inspection of Piezoceramic Transducers Used for Structural Health Monitoring

PubMed Central

Mueller, Inka; Fritzen, Claus-Peter

2017-01-01

The use of piezoelectric wafer active sensors (PWAS) for structural health monitoring (SHM) purposes is state of the art for acousto-ultrasonic-based methods. For system reliability, detailed information about the PWAS itself is necessary. This paper gives an overview on frequent PWAS faults and presents the effects of these faults on the wave propagation, used for active acousto-ultrasonics-based SHM. The analysis of the wave field is based on velocity measurements using a laser Doppler vibrometer (LDV). New and established methods of PWAS inspection are explained in detail, listing advantages and disadvantages. The electro-mechanical impedance spectrum as basis for these methods is discussed for different sensor faults. This way this contribution focuses on a detailed analysis of PWAS and the need of their inspection for an increased reliability of SHM systems. PMID:28772431

High Temperature Ultrasonic Transducer for Real-time Inspection

NASA Astrophysics Data System (ADS)

Amini, Mohammad Hossein; Sinclair, Anthony N.; Coyle, Thomas W.

A broadband ultrasonic transducer with a novel porous ceramic backing layer is introduced to operate at 700 °C. 36° Y-cut lithium niobate (LiNbO3) single crystal was selected for the piezoelectric element. By appropriate choice of constituent materials, porosity and pore size, the acoustic impedance and attenuation of a zirconia-based backing layer were optimized. An active brazing alloy with high temperature and chemical stability was selected to bond the transducer layers together. Prototype transducers have been tested at temperatures up to 700 °C. The experiments confirmed that transducer integrity was maintained.

Ultrasonic scanning system for in-place inspection of brazed-tube joints

NASA Technical Reports Server (NTRS)

Haralson, H. S.; Haynes, J. L.; Wages, C. G.

1971-01-01

System detects defects of .051 cm in diameter and larger. System incorporates scanning head assembly including boot enclosed transducer, slip ring assembly, drive mechanism, and servotransmitter. Ultrasonic flaw detector, prototype recorder, and special recorder complete system.

Hearing-Impaired Formal Inservice Program.

ERIC Educational Resources Information Center

Northeast Regional Media Center for the Deaf, Amherst, MA.

The HI-FI (Hearing-Impaired Formal Inservice) Program is described as a set of inservice materials targeted for workshops of regular classroom teachers and other school personnel concerned with school district and classroom management of hearing impaired (HI) children. An introductory section focuses on the design of the program materials,…

Determination of tire quality from nondestructive inspection : final report

DOT National Transportation Integrated Search

1979-11-01

The principal objective of the study was to assess the capability of an ultrasonic nondestructive inspection system to identify tire groups with a high propensity to failure among the groups selected for the Compliance Test under MVSS 109. A secondar...

Ultrasonic scanning system for in-place inspection of brazed tube joints

NASA Technical Reports Server (NTRS)

Haynes, J. L.; Wages, C. G.; Haralson, H. S. (Inventor)

1973-01-01

A miniaturized ultrasonic scanning system for nondestructive in-place, non-immersion testing of brazed joints in stainless-steel tubing is described. The system is capable of scanning brazed tube joints, with limited clearance access, in 1/4 through 5/8 inch union, tee, elbow and cross configurations. The system has the capability to detect defective conditions now associated with material density changes in addition to those which are depended upon density variations. The system includes a miniaturized scanning head assembly that fits around a tube joint and rotates the transducer around and down the joint in a continuous spiral motion. The C-scan recorder is similar in principle to conventional models except that it was specially designed to track the continuous spiral scan of the tube joint. The scanner and recorder can be operated with most commercially available ultrasonic flaw detectors.

Computer-Integrated Instruction Inservice Notebook: Secondary School Social Studies.

ERIC Educational Resources Information Center

Franklin, Sharon, Ed.; Strudler, Neal, Ed.

The purpose of this notebook is to assist educators who are designing and implementing inservice education programs to facilitate the effective use of computer integrated instruction (CII) in schools. It is divided into the following five sections: (1) Effective Inservice (a brief summary of inservice literature focused on inservice dimensions and…

High energy, low frequency, ultrasonic transducer

DOEpatents

Brown, Albert E.

2000-01-01

A wide bandwidth, ultrasonic transducer to generate nondispersive, extensional, pulsed acoustic pressure waves into concrete reinforced rods and tendons. The wave propagation distance is limited to double the length of the rod. The transducer acoustic impedance is matched to the rod impedance for maximum transfer of acoustic energy. The efficiency of the transducer is approximately 60 percent, depending upon the type of active elements used in the transducer. The transducer input energy is, for example, approximately 1 mJ. Ultrasonic reflections will occur at points along the rod where there are changes of one percent of a wavelength in the rod diameter. A reduction in the rod diameter will reflect a phase reversed echo, as compared with the reflection from an incremental increase in diameter. Echo signal processing of the stored waveform permits a reconstruction of those echoes into an image of the rod. The ultrasonic transducer has use in the acoustic inspection of long (40+foot) architectural reinforcements and structural supporting members, such as in bridges and dams.

Sandwich Panels Evaluated With Ultrasonic Spectroscopy

NASA Technical Reports Server (NTRS)

Cosgriff, Laura M.

2004-01-01

Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment systems for next-generation engines. The bond strength between the core and face sheets is critical in maintaining the structural integrity of the sandwich structure. To improve the inspection and production of these systems, researchers at the NASA Glenn Research Center are using nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, to evaluate the brazing quality between the face plates and the metallic foam core. The capabilities and limitations of a swept-frequency approach to ultrasonic spectroscopy were evaluated with respect to these sandwich structures. This report discusses results from three regions of a sandwich panel representing different levels of brazing quality between the outer face plates and a metallic foam core. Each region was investigated with ultrasonic spectroscopy. Then, on the basis of the NDE results, three shear specimens sectioned from the sandwich panel to contain each of these regions were mechanically tested.

High-speed scanning of critical structures in aviation using coordinate measurement machine and the laser ultrasonic.

PubMed

Swornowski, Pawel J

2012-01-01

Aviation is one of the know-how spheres containing a great deal of responsible sub-assemblies, in this case landing gear. The necessity for reducing production cycle times while achieving better quality compels metrologists to look for new and improved ways to perform inspection of critical structures. This article describes the ability to determine the shape deviation and location of defects in landing gear using coordinate measuring machines and laser ultrasonic with high-speed scanning. A nondestructive test is the basis for monitoring microcrack and corrosion propagation in the context of a damage-tolerant design approach. This article presents an overview of the basics and of the various metrological aspects of coordinate measurement and a nondestructive testing method in terms of high-speed scanning. The new test method (laser ultrasonic) promises to produce the necessary increase in inspection quality, but this is limited by the wide range of materials, geometries, and structure aeronautic parts used. A technique combining laser ultrasonic and F-SAFT (Fourier-Synthetic Aperture Focusing Technique) processing has been proposed for the detection of small defects buried in landing gear. The experimental results of landing gear inspection are also presented. © Wiley Periodicals, Inc.

Modeling of ultrasonic wave propagation in composite laminates with realistic discontinuity representation.

PubMed

Zelenyak, Andreea-Manuela; Schorer, Nora; Sause, Markus G R

2018-02-01

This paper presents a method for embedding realistic defect geometries of a fiber reinforced material in a finite element modeling environment in order to simulate active ultrasonic inspection. When ultrasonic inspection is used experimentally to investigate the presence of defects in composite materials, the microscopic defect geometry may cause signal characteristics that are difficult to interpret. Hence, modeling of this interaction is key to improve our understanding and way of interpreting the acquired ultrasonic signals. To model the true interaction of the ultrasonic wave field with such defect structures as pores, cracks or delamination, a realistic three dimensional geometry reconstruction is required. We present a 3D-image based reconstruction process which converts computed tomography data in adequate surface representations ready to be embedded for processing with finite element methods. Subsequent modeling using these geometries uses a multi-scale and multi-physics simulation approach which results in quantitative A-Scan ultrasonic signals which can be directly compared with experimental signals. Therefore, besides the properties of the composite material, a full transducer implementation, piezoelectric conversion and simultaneous modeling of the attached circuit is applied. Comparison between simulated and experimental signals provides very good agreement in electrical voltage amplitude and the signal arrival time and thus validates the proposed modeling approach. Simulating ultrasound wave propagation in a medium with a realistic shape of the geometry clearly shows a difference in how the disturbance of the waves takes place and finally allows more realistic modeling of A-scans. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasonic guided wave interpretation for structural health inspections

NASA Astrophysics Data System (ADS)

Bingham, Jill Paisley

Structural Health Management (SHM) combines the use of onboard sensors with artificial intelligence algorithms to automatically identify and monitor structural health issues. A fully integrated approach to SHM systems demands an understanding of the sensor output relative to the structure, along with sophisticated prognostic systems that automatically draw conclusions about structural integrity issues. Ultrasonic guided wave methods allow us to examine the interaction of multimode signals within key structural components. Since they propagate relatively long distances within plate- and shell-like structures, guided waves allow inspection of greater areas with fewer sensors, making this technique attractive for a variety of applications. This dissertation describes the experimental development of automatic guided wave interpretation for three real world applications. Using the guided wave theories for idealized plates we have systematically developed techniques for identifying the mass loading of underwater limpet mines on US Navy ship hulls, characterizing type and bonding of protective coatings on large diameter pipelines, and detecting the thinning effects of corrosion on aluminum aircraft structural stringers. In each of these circumstances the signals received are too complex for interpretation without knowledge of the guided wave physics. We employ a signal processing technique called the Dynamic Wavelet Fingerprint Technique (DFWT) in order to render the guided wave mode information in two-dimensional binary images. The use of wavelets allows us to keep track of both time and scale features from the original signals. With simple image processing we have developed automatic extraction algorithms for features that correspond to the arrival times of the guided wave modes of interest for each of the applications. Due to the dispersive nature of the guided wave modes, the mode arrival times give details of the structure in the propagation path. For further

Resonant frequency method for bearing ball inspection

DOEpatents

Khuri-Yakub, B.T.; Chungkao Hsieh.

1993-11-02

The present invention provides for an inspection system and method for detecting defects in test objects which includes means for generating expansion inducing energy focused upon the test object at a first location, such expansion being allowed to contract, thereby causing pressure wave within and on the surface of the test object. Such expansion inducing energy may be provided by, for example, a laser beam or ultrasonic energy. At a second location, the amplitudes and phases of the acoustic waves are detected and the resonant frequencies' quality factors are calculated and compared to predetermined quality factor data, such comparison providing information of whether the test object contains a defect. The inspection system and method also includes means for mounting the bearing ball for inspection. 5 figures.

Resonant frequency method for bearing ball inspection

DOEpatents

Khuri-Yakub, B. T.; Hsieh, Chung-Kao

1993-01-01

The present invention provides for an inspection system and method for detecting defects in test objects which includes means for generating expansion inducing energy focused upon the test object at a first location, such expansion being allowed to contract, thereby causing pressure wave within and on the surface of the test object. Such expansion inducing energy may be provided by, for example, a laser beam or ultrasonic energy. At a second location, the amplitudes and phases of the acoustic waves are detected and the resonant frequencies' quality factors are calculated and compared to predetermined quality factor data, such comparison providing information of whether the test object contains a defect. The inspection system and method also includes means for mounting the bearing ball for inspection.

Telecommunications: Graduate & Inservice. [SITE 2001 Section].

ERIC Educational Resources Information Center

Espinoza, Sue, Ed.

This document contains the following papers on graduate and inservice telecommunications from the SITE (Society for Information Technology & Teacher Education) 2001 Conference: (1) "Teaching Technology with Technology" (Michelle Adelman and Susan Luftschein); (2) "Standards of Practice: Online Educator Inservice Workshop" (Cathy and Terry…

Advanced ultrasonic measurement methodology for non-invasive interrogation and identification of fluids in sealed containers

NASA Astrophysics Data System (ADS)

Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

2006-03-01

Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

Effects of Porosity on Ultrasonic Characteristic Parameters and Mechanical Properties of Glass Fiber Reinforced Composites

NASA Astrophysics Data System (ADS)

Ma, Wen; Liu, Fushun

Voids are inevitable in the fabrication of fiber reinforced composites and have a detrimental impact on mechanical properties of composites. Different void contents were acquired by applying different vacuum bag pressures. Ultrasonic inspection and ablation density method were adopted to measure the ultrasonic characteristic parameters and average porosity, the characterization of voids' distribution, shape and size were carried out through metallographic analysis. Effects of void content on the tensile, flexural and interlaminar shear properties and the ultrasonic characteristic parameters were discussed. The results showed that, as vacuum bag pressure went from -50kPa to -98kPa, the voids content decreased from 4.36 to 0.34, the ultrasonic attenuation coefficient decreased, but the mechanical strengths all increased.

Further testing and development of simulation models for UT inspections of armor

NASA Astrophysics Data System (ADS)

Margetan, Frank J.; Richter, Nathaniel; Thompson, R. Bruce

2012-05-01

In previous work we introduced an approach for simulating ultrasonic pulse/echo immersion inspections of multi-layer armor panels. Model inputs include the thickness, density, velocity and attenuation of each armor layer, the focal properties of the transducer, and a measured calibration signal. The basic model output is a response-versus-time waveform (ultrasonic A-scan) which includes echoes from all interfaces including those arising from reverberations within layers. Such A-scans can be predicted both for unflawed panels and panels containing a large disbond at any given interface. In this paper we continue our testing of the simulation software, applying it now to an armor panel consisting of SiC ceramic tiles fully embedded in a titanium-alloy matrix. An interesting specimen of such armor became available in which some tile/metal interfaces appear to be well bonded, while others have disbonded areas of various sizes. We compare measured and predicted A-scans for UT inspections, and also demonstrate an extension of the model to predict ultrasonic C-scans over regions containing a small, isolated disbond.

Emerging nondestructive inspection methods for aging aircraft

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

Beattie, A; Dahlke, L; Gieske, J

This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with amore » discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.« less

Ultrasonic Wall Thickness Monitoring at High Temperatures (>500 °C)

NASA Astrophysics Data System (ADS)

Cegla, F. B.; Allin, J.; Davies, J. O.; Collins, P.; Cawley, P.

2011-06-01

Corrosion and erosion shorten the life of components that are used in the petrochemical industry. In order to mitigate the safety and financial risks posed by the degradation mechanisms, plant operators monitor wall thicknesses at regular inspection intervals. In high temperature locations inspections have to be carried out at plant shut downs because conventional ultrasonic sensors cannot withstand the high operating temperatures. The authors have developed a waveguide based high temperature thickness gauge for monitoring of wall thicknesses in high temperature areas. The waveguide allows the use of conventional transduction systems (max temp. 60 °C) at one end and guides ultrasonic waves into the high temperature region where the inspection is to be carried out. Slender stainless steel waveguides allow a temperature drop of ˜500-600 °C per 200 mm length to be sustained simply by natural convection cooling. This paper describes the technical challenges that had to be overcome (dispersion and source/receiver characteristics) in order to implement this "acoustic cable". A range of experimental results of thickness measurements on components of different thickness, and furnace tests at different temperatures are presented. An accelerated corrosion test that demonstrates the effectiveness of the monitoring for corrosion is also presented.

Psychodrama Techniques for Inservice Teacher Training

ERIC Educational Resources Information Center

Kohut, Sylvester, Jr.

1976-01-01

By using psychodrama techniques in inservice programming, improvement in communication among members of the school community occurs. With modification the psychodrama approach can be used with inservice teachers and administrators to improve self-realization and communication. A program using psychodrama techniques is described in the article.…

Recent modelling advances for ultrasonic TOFD inspections

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

Darmon, Michel; Ferrand, Adrien; Dorval, Vincent

The ultrasonic TOFD (Time of Flight Diffraction) Technique is commonly used to detect and characterize disoriented cracks using their edge diffraction echoes. An overview of the models integrated in the CIVA software platform and devoted to TOFD simulation is presented. CIVA allows to predict diffraction echoes from complex 3D flaws using a PTD (Physical Theory of Diffraction) based model. Other dedicated developments have been added to simulate lateral waves in 3D on planar entry surfaces and in 2D on irregular surfaces by a ray approach. Calibration echoes from Side Drilled Holes (SDHs), specimen echoes and shadowing effects from flaws canmore » also been modelled. Some examples of theoretical validation of the models are presented. In addition, experimental validations have been performed both on planar blocks containing calibration holes and various notches and also on a specimen with an irregular entry surface and allow to draw conclusions on the validity of all the developed models.« less

Perpetual Motion, Blindman's Buff, and Inservice Education.

ERIC Educational Resources Information Center

Houston, W. Robert; Freiberg, H. Jerome

1979-01-01

Issues relating to in-service education are highlighted including professional lifespace, resource allocation, validity, systemic designs, collaboration, and the responsibility for in-service education of teachers as professionals and employees. (JMF)

30 CFR 285.824 - How must I conduct self-inspections?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Section 285.824 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER... months; (2) The type of inspection employed, (i.e., visual, magnetic particle, ultrasonic testing); and...

Ultrasonic guided waves in eccentric annular pipes

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

Pattanayak, Roson Kumar; Balasubramaniam, Krishnan; Rajagopal, Prabhu

2014-02-18

This paper studies the feasibility of using ultrasonic guided waves to rapidly inspect tubes and pipes for possible eccentricity. While guided waves are well established in the long range inspection of structures such as pipes and plates, studies for more complex cross sections are limited and analytical solutions are often difficult to obtain. Recent developments have made the Semi Analytical Finite Element (SAFE) method widely accessible for researchers to study guided wave properties in complex structures. Here the SAFE method is used to study the effect of eccentricity on the modal structures and velocities of lower order guided wave modesmore » in thin pipes of diameters typically of interest to the industry. Results are validated using experiments. The paper demonstrates that even a small eccentricity in the pipe can strongly affect guided wave mode structures and velocities and hence shows potential for pipe eccentricity inspection.« less

Ultrasonic NDE Simulation for Composite Manufacturing Defects

NASA Technical Reports Server (NTRS)

Leckey, Cara A. C.; Juarez, Peter D.

2016-01-01

The increased use of composites in aerospace components is expected to continue into the future. The large scale use of composites in aerospace necessitates the development of composite-appropriate nondestructive evaluation (NDE) methods to quantitatively characterize defects in as-manufactured parts and damage incurred during or post manufacturing. Ultrasonic techniques are one of the most common approaches for defect/damage detection in composite materials. One key technical challenge area included in NASA's Advanced Composite's Project is to develop optimized rapid inspection methods for composite materials. Common manufacturing defects in carbon fiber reinforced polymer (CFRP) composites include fiber waviness (in-plane and out-of-plane), porosity, and disbonds; among others. This paper is an overview of ongoing work to develop ultrasonic wavefield based methods for characterizing manufacturing waviness defects. The paper describes the development and implementation of a custom ultrasound simulation tool that is used to model ultrasonic wave interaction with in-plane fiber waviness (also known as marcelling). Wavefield data processing methods are applied to the simulation data to explore possible routes for quantitative defect characterization.

30 CFR 585.824 - How must I conduct self-inspections?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 585.824 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Environmental and... inspection employed, (i.e., visual, magnetic particle, ultrasonic testing); and (3) A summary of the...

30 CFR 585.824 - How must I conduct self-inspections?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Section 585.824 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Environmental and... inspection employed, (i.e., visual, magnetic particle, ultrasonic testing); and (3) A summary of the...

30 CFR 585.824 - How must I conduct self-inspections?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Section 585.824 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Environmental and... inspection employed, (i.e., visual, magnetic particle, ultrasonic testing); and (3) A summary of the...

Modelling NDE pulse-echo inspection of misorientated planar rough defects using an elastic finite element method

NASA Astrophysics Data System (ADS)

Pettit, J. R.; Walker, A. E.; Lowe, M. J. S.

2015-03-01

Pulse-echo ultrasonic NDE examination of large pressure vessel forgings is a design and construction code requirement in the power generation industry. Such inspections aim to size and characterise potential defects that may have formed during the forging process. Typically these defects have a range of orientations and surface roughnesses which can greatly affect ultrasonic wave scattering behaviour. Ultrasonic modelling techniques can provide insight into defect response and therefore aid in characterisation. However, analytical approaches to solving these scattering problems can become inaccurate, especially when applied to increasingly complex defect geometries. To overcome these limitations a elastic Finite Element (FE) method has been developed to simulate pulse-echo inspections of embedded planar defects. The FE model comprises a significantly reduced spatial domain allowing for a Monte-Carlo based approach to consider multiple realisations of defect orientation and surface roughness. The results confirm that defects aligned perpendicular to the path of beam propagation attenuate ultrasonic signals according to the level of surface roughness. However, for defects orientated away from this plane, surface roughness can increase the magnitude of the scattered component propagating back along the path of the incident beam. This study therefore highlights instances where defect roughness increases the magnitude of ultrasonic scattered signals, as opposed to attenuation which is more often assumed.

Ultrasonic Characterization of Fatigue Cracks in Composite Materials

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Watson, Jason; Johnson, Devin; Walker, James; Russell, Sam; Thom, Robert (Technical Monitor)

2002-01-01

Microcracking in composite structures due to combined fatigue and cryogenic loading can cause leakage and failure of the structure and can be difficult to detect in-service. In aerospace systems, these leaks may lead to loss of pressure/propellant, increased risk of explosion and possible cryo-pumping. The success of nondestructive evaluation to detect intra-ply microcracking in unlined pressure vessels fabricated from composite materials is critical to the use of composite structures in future space systems. The work presented herein characterizes measurements of intraply fatigue cracking through the thickness of laminated composite material by means of correlation with ultrasonic resonance. Resonant ultrasound spectroscopy provides measurements which are sensitive to both the microscopic and macroscopic properties of the test article. Elastic moduli, acoustic attenuation, and geometry can all be probed. The approach is based on the premise of half-wavelength resonance. The method injects a broadband ultrasonic wave into the test structure using a swept frequency technique. This method provides dramatically increased energy input into the test article, as compared to conventional pulsed ultrasonics. This relative energy increase improves the ability to measure finer details in the materials characterization, such as microcracking and porosity. As the microcrack density increases, more interactions occur with the higher frequency (small wavelength) components of the signal train causing the spectrum to shift toward lower frequencies. Several methods are under investigation to correlate the degree of microcracking from resonance ultrasound measurements on composite test articles including self organizing neural networks, chemometric techniques used in optical spectroscopy and other clustering algorithms.

Characterization of flaws in a tube bundle mock-up for reliability studies

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

Kupperman, D.S.; Bakhtiari, S.

1997-02-01

As part of an assessment of in-service inspection of steam generator tubes, the authors will assemble a steam generator mock-up for round robin studies and use as a test bed in evaluating emerging technologies. Progress is reported on the characterization of flaws that will be part of the mock-up. Eddy current and ultrasonic techniques are being evaluated as a means to characterize the flaws in the mock-up tubes before final assembly. Twenty Inconel 600 tubes with laboratory-grown cracks, typical of those to be used in the mock-up, were provided by Pacific Northwest National Laboratory for laboratory testing. After the tubesmore » were inspected with eddy current and ultrasonic techniques, they were destructively analyzed to establish the actual depths, lengths, and profiles of the cracks. The analysis of the results will allow the best techniques to be used for characterizing the flaws in the mock-up tubes.« less

Prediction of Building Limestone Physical and Mechanical Properties by Means of Ultrasonic P-Wave Velocity

PubMed Central

Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

2014-01-01

The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r 2 between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced. PMID:24511286

Application of laser ultrasonic method for on-line monitoring of friction stir spot welding process.

PubMed

Zhang, Kuanshuang; Zhou, Zhenggan; Zhou, Jianghua

2015-09-01

Application of a laser ultrasonic method is developed for on-line monitoring of the friction stir spot welding (FSSW) process. Based on the technology of FSSW, laser-generated ultrasonic waves in a good weld and nonweld area are simulated by a finite element method. The reflected and transmitted waves are analyzed to disclose the properties of the welded interface. The noncontact-laser ultrasonic-inspection system was established to verify the numerical results. The reflected waves in the good-weld and nonweld area can be distinguished by time-of-flight. The transmitted waves evidently attenuate in the nonweld area in contrast to signal amplitude in the good weld area because of interfacial impedance difference. Laser ultrasonic C-scan images can sufficiently evaluate the intrinsic character of the weld area in comparison with traditional water-immersion ultrasonic testing results. The research results confirm that laser ultrasonics would be an effective method to realize the characterization of FSSW defects.

Prediction of building limestone physical and mechanical properties by means of ultrasonic P-wave velocity.

PubMed

Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

2014-01-01

The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r(2) between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced.

Eddy current system for inspection of train hollow axles

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

Chady, Tomasz; Psuj, Grzegorz; Sikora, Ryszard

2014-02-18

The structural integrity of wheelsets used in rolling stock is of great importance to the safety. In this paper, electromagnetic system with an eddy current transducer suitable for the inspection of hollow axles have been presented. The transducer was developed to detect surface braking defects having depth not smaller than 0.5 mm. Ultrasound technique can be utilized to inspect the whole axle, but it is not sufficiently sensitive to shallow defects located close to the surface. Therefore, the electromagnetic technique is proposed to detect surface breaking cracks that cannot be detected by ultrasonic technique.

18. Interior view, 'Inside Key Route Inspection Bldg.', view to ...

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

18. Interior view, 'Inside Key Route Inspection Bldg.', view to east, August 16, 1939. Note inspection pits and work areas beneath tracks. The Key Route and Interurban Electric Railway Bridge Yard Shop buildings were identical, and this view provides an in-service look at the well-lit interior. While Key Route articulated cars were quite different in design from the Interurban Electric Railway cars, the maintenance requirements were quite similar. The Key Route Bridge Yard Shop building was demolished in the 1970s. Its last use was storage of much of the historic railway equipment now on display at the California State Railroad Museum in Sacramento. - Interurban Electric Railway Bridge Yard Shop, Interstate 80 at Alameda County Postmile 2.0, Oakland, Alameda County, CA

Correlation Between Ultrasonic Nondestructive Inspection and Wheel Test of 34 Retreaded Tires

DOT National Transportation Integrated Search

1979-11-01

The report covers a test in which 34 retread tires were inspected using reflection ultrasound nondestructive inspection, wheel tested and then subjected to failure analysis by sectioning. The results demonstrate for the first time the ability of ultr...

Inservice Education Manual for Long-Term Care Facilities in South Carolina.

ERIC Educational Resources Information Center

South Carolina State Board for Technical and Comprehensive Education, Columbia.

The manual contains comprehensive multidisciplinary training units for supervisors intending to conduct inservice education courses among health personnel in South Carolina nursing homes. The first five units provide a general orientation to inservice education: introduction, the supervisor and inservice education, what inservice can and can't do,…

Detection of defects in multi-layered aramid composites by ultrasonic IR thermography

NASA Astrophysics Data System (ADS)

Pracht, Monika; Swiderski, Waldemar

2017-10-01

In military applications, laminates reinforced with aramid, carbon, and glass fibers are used for the construction of protection products against light ballistics. Material layers can be very different by their physical properties. Therefore, such materials represent a difficult inspection task for many traditional techniques of non-destructive testing (NDT). Defects which can appear in this type of many-layered composite materials usually are inaccuracies in gluing composite layers and stratifications or delaminations occurring under hits of fragments and bullets. IR thermographic NDT is considered as a candidate technique to detect such defects. One of the active IR thermography methods used in nondestructive testing is vibrothermography. The term vibrothermography was created in the 1990s to determine the thermal test procedures designed to assess the hidden heterogeneity of structural materials based on surface temperature fields at cyclical mechanical loads. A similar procedure can be done with sound and ultrasonic stimulation of the material, because the cause of an increase in temperature is internal friction between the wall defect and the stimulation mechanical waves. If the cyclic loading does not exceed the flexibility of the material and the rate of change is not large, the heat loss due to thermal conductivity is small, and the test object returns to its original shape and temperature. The most commonly used method is ultrasonic stimulation, and the testing technique is ultrasonic infrared thermography. Ultrasonic IR thermography is based on two basic phenomena. First, the elastic properties of defects differ from the surroundings, and acoustic damping and heating are always larger in the damaged regions than in the undamaged or homogeneous areas. Second, the heat transfer in the sample is dependent on its thermal properties. In this paper, both modelling and experimental results which illustrate the advantages and limitations of ultrasonic IR

Ultrasonic Sound Field Mapping Through Coarse Grained Cast Austenitic Stainless Steel Components

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

Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.

2014-08-01

The Pacific Northwest National Laboratory (PNNL) has been involved with nondestructive examination (NDE) of coarse-grained cast austenitic stainless steel (CASS) components for over 30 years. More recent work has focused on mapping the ultrasonic sound fields generated by low-frequency phased array probes that are typically used for the evaluation of CASS materials for flaw detection and characterization. The casting process results in the formation of large grained material microstructures that are nonhomogeneous and anisotropic. The propagation of ultrasonic energy for examination of these materials results in scattering, partitioning and redirection of these sound fields. The work reported here provides anmore » assessment of sound field formation in these materials and provides recommendations on ultrasonic inspection parameters for flaw detection in CASS components.« less

MEMS ultrasonic transducer for monitoring of steel structures

NASA Astrophysics Data System (ADS)

Jain, Akash; Greve, David W.; Oppenheim, Irving J.

2002-06-01

Ultrasonic methods can be used to monitor crack propagation, weld failure, or section loss at critical locations in steel structures. However, ultrasonic inspection requires a skilled technician, and most commonly the signal obtained at any inspection is not preserved for later use. A preferred technology would use a MEMS device permanently installed at a critical location, polled remotely, and capable of on-chip signal processing using a signal history. We review questions related to wave geometry, signal levels, flaw localization, and electromechanical design issues for microscale transducers, and then describe the design, characterization, and initial testing of a MEMS transducer to function as a detector array. The device is approximately 1-cm square and was fabricated by the MUMPS process. The chip has 23 sensor elements to function in a phased array geometry, each element containing 180 hexagonal polysilicon diaphragms with a typical leg length of 49 microns and an unloaded natural frequency near 3.5 MHz. We first report characterization studies including capacitance-voltage measurements and admittance measurements, and then report initial experiments using a conventional piezoelectric transducer for excitation, with successful detection of signals in an on-axis transmission experiment and successful source localization from phased array performance in an off-axis transmission experiment.

Ultrasonic Real-Time Quality Monitoring Of Aluminum Spot Weld Process

NASA Astrophysics Data System (ADS)

Perez Regalado, Waldo Josue

The real-time ultrasonic spot weld monitoring system, introduced by our research group, has been designed for the unsupervised quality characterization of the spot welding process. It comprises the ultrasonic transducer (probe) built into one of the welding electrodes and an electronics hardware unit which gathers information from the transducer, performs real-time weld quality characterization and communicates with the robot programmable logic controller (PLC). The system has been fully developed for the inspection of spot welds manufactured in steel alloys, and has been mainly applied in the automotive industry. In recent years, a variety of materials have been introduced to the automotive industry. These include high strength steels, magnesium alloys, and aluminum alloys. Aluminum alloys have been of particular interest due to their high strength-to-weight ratio. Resistance spot welding requirements for aluminum vary greatly from those of steel. Additionally, the oxide film formed on the aluminum surface increases the heat generation between the copper electrodes and the aluminum plates leading to accelerated electrode deterioration. Preliminary studies showed that the real-time quality inspection system was not able to monitor spot welds manufactured with aluminum. The extensive experimental research, finite element modelling of the aluminum welding process and finite difference modeling of the acoustic wave propagation through the aluminum spot welds presented in this dissertation, revealed that the thermodynamics and hence the acoustic wave propagation through an aluminum and a steel spot weld differ significantly. For this reason, the hardware requirements and the algorithms developed to determine the welds quality from the ultrasonic data used on steel, no longer apply on aluminum spot welds. After updating the system and designing the required algorithms, parameters such as liquid nugget penetration and nugget diameter were available in the ultrasonic data

Modelling NDE pulse-echo inspection of misorientated planar rough defects using an elastic finite element method

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

Pettit, J. R.; Lowe, M. J. S.; Walker, A. E.

2015-03-31

Pulse-echo ultrasonic NDE examination of large pressure vessel forgings is a design and construction code requirement in the power generation industry. Such inspections aim to size and characterise potential defects that may have formed during the forging process. Typically these defects have a range of orientations and surface roughnesses which can greatly affect ultrasonic wave scattering behaviour. Ultrasonic modelling techniques can provide insight into defect response and therefore aid in characterisation. However, analytical approaches to solving these scattering problems can become inaccurate, especially when applied to increasingly complex defect geometries. To overcome these limitations a elastic Finite Element (FE) methodmore » has been developed to simulate pulse-echo inspections of embedded planar defects. The FE model comprises a significantly reduced spatial domain allowing for a Monte-Carlo based approach to consider multiple realisations of defect orientation and surface roughness. The results confirm that defects aligned perpendicular to the path of beam propagation attenuate ultrasonic signals according to the level of surface roughness. However, for defects orientated away from this plane, surface roughness can increase the magnitude of the scattered component propagating back along the path of the incident beam. This study therefore highlights instances where defect roughness increases the magnitude of ultrasonic scattered signals, as opposed to attenuation which is more often assumed.« less

A Different Approach to In-Service Education.

ERIC Educational Resources Information Center

Jackson, Michael; Stuck, Dean

1987-01-01

Describes the implementation year of the Renewal Institute for Practicing Educators (RI) of Southern Illinois University, an in-service education program that follows up on participants to determine whether teachers are implementing the ideas and suggestions offered during the original program. The RI program provides in-service education…

Latest technologies on ultrasonic cleaning

NASA Astrophysics Data System (ADS)

Hofstetter, Hans U.

2007-05-01

UCM-AG manufactures Ultrasonic Cleaning Machines for highest quality requirements. The company has the know-how for cleaning and supplies cleaning systems together with the cleaning process. With a UCM of Switzerland Cleaning System, the customer gets the system itself, the cleaning process with a guarantee for the specified result but also all auxiliary equipment needed for perfect results. Therefore UCM also supplies fixtures, linkage to existing automated fabrication facilities water treatment plants etc. Thus the UCM customer gets a turnkey installation - ready to operate and including know-how. UCM of Switzerland will describe the latest technology in ultrasonic precision cleaning on the example of a recent and sophisticated installation. The installation consists of three interlinked cleaning systems which operate completely automated. The 1st system is designed for pre-cleaning to remove waxes, pitch and protection lacquers with environmentally friendly solvents which are non hazardous to the health of the operators. The 2nd system cleans the parts prior to inspection and operates with neutral or slightly alkaline detergents. The 3rd system is designed for final cleaning prior to vacuum coating and perfect results are required. It combines cleaning tanks and DI-Water rinse with lift out and vacuum dryer. The installation combines the latest technologies in ultrasonic cleaning for precision optical components. The system employs multi frequency immersed ultrasonic transducers and special rinsing technologies The complete installation will be explained in detail; the concept in its whole, the lay out, the particular setup of each cleaning system etc. will be shown and explained together with construction particulars of the complete installation.

Phased array inspection of large size forged steel parts

NASA Astrophysics Data System (ADS)

Dupont-Marillia, Frederic; Jahazi, Mohammad; Belanger, Pierre

2018-04-01

High strength forged steel requires uncompromising quality to warrant advance performance for numerous critical applications. Ultrasonic inspection is commonly used in nondestructive testing to detect cracks and other defects. In steel blocks of relatively small dimensions (at least two directions not exceeding a few centimetres), phased array inspection is a trusted method to generate images of the inside of the blocks and therefore identify and size defects. However, casting of large size forged ingots introduces changes of mechanical parameters such as grain size, the Young's modulus, the Poisson's ratio, and the chemical composition. These heterogeneities affect the wave propagation, and consequently, the reliability of ultrasonic inspection and the imaging capabilities for these blocks. In this context, a custom phased array transducer designed for a 40-ton bainitic forged ingot was investigated. Following a previous study that provided local mechanical parameters for a similar block, two-dimensional simulations were made to compute the optimal transducer parameters including the pitch, width and number of elements. It appeared that depending on the number of elements, backwall reconstruction can generate high amplitude artefacts. Indeed, the large dimensions of the simulated block introduce numerous constructive interferences from backwall reflections which may lead to important artefacts. To increase image quality, the reconstruction algorithm was adapted and promising results were observed and compared with the scattering cone filter method available in the CIVA software.

Apparatus for the concurrent inspection of partially completed welds

DOEpatents

Smartt, Herschel B.; Johnson, John A.; Larsen, Eric D.; Bitsoi, Rodney J.; Perrenoud, Ben C.; Miller, Karen S.; Pace, David P.

2002-01-01

An apparatus for the concurrent inspection of partially completed welds is described in which is utilized in combination with a moveable welder for forming a partially completed weld, and an ultrasonic generator mounted on a moveable welder in which is reciprocally moveable along a path of travel which is laterally disposed relative to the partially completed weld.

A fast ultrasonic simulation tool based on massively parallel implementations

NASA Astrophysics Data System (ADS)

Lambert, Jason; Rougeron, Gilles; Lacassagne, Lionel; Chatillon, Sylvain

2014-02-01

This paper presents a CIVA optimized ultrasonic inspection simulation tool, which takes benefit of the power of massively parallel architectures: graphical processing units (GPU) and multi-core general purpose processors (GPP). This tool is based on the classical approach used in CIVA: the interaction model is based on Kirchoff, and the ultrasonic field around the defect is computed by the pencil method. The model has been adapted and parallelized for both architectures. At this stage, the configurations addressed by the tool are : multi and mono-element probes, planar specimens made of simple isotropic materials, planar rectangular defects or side drilled holes of small diameter. Validations on the model accuracy and performances measurements are presented.

Exploration of COTS Ultrasonic NDE Methods for ISS MMOD Impact Analysis

NASA Technical Reports Server (NTRS)

Violette, Daniel P.; Koshti, Ajay; Stanley, David

2012-01-01

The high orbital speed of the International Space Station (ISS) has created a concern about Micro-Meteorite and Orbital Debris (MMOD). The possibility exists that such an impact could cause significant damage to the ISS pressure wall, and possibly lead to a pressure leak. This paper explores the potential of using commercial off-the-shelf (COTS) Ultrasonic Non-Destructive Evaluation (NDE) techniques in order to inspect and analyze MMOD impact damage if such an event would happen to occur. Different types of intra vehicular activity (IVA) Ultrasonic NDE equipment were evaluated, including the Olympus Omniscan MX and the General Electric Phasor XS. The equipment was tested by inspecting various aluminum standards and impact damage test plates in order to determine technological limitations of the equipment as well as the ease of use and availability of features. This study allowed for the design of scanning procedures in order to evaluate the extent of damage caused by an MMOD impact. Lastly, comparisons were drawn between the different pieces of COTS software and a recommendation is made based on each device s capability.

On-Site Evaluation of Large Components Using Saft and Tofd Ultrasonic Imaging

NASA Astrophysics Data System (ADS)

Spies, M.; Rieder, H.; Dillhöfer, A.

2011-06-01

This contribution addresses ultrasonic inspection and evaluation of welds in large components. An approach has been developed in order to enhance the reliability of welded ship propellers. The Synthetic Aperture Focusing Technique (SAFT) has been modified with regard to the curved surfaces and the sound attenuation of cast Ni-Al bronzes. For weld inspection in steels the Time-of-Flight Diffraction technique (TOFD) can provide additional information for specific defect orientations. Both techniques have been combined in view of the determination of defect sizes and shapes in longitudinal welds of pipes with diameters of up to 48 inches. Details on the inspection and evaluation concepts as well as experimental results are presented.

Design and demonstration of automated data analysis algorithms for ultrasonic inspection of complex composite panels with bonds

NASA Astrophysics Data System (ADS)

Aldrin, John C.; Forsyth, David S.; Welter, John T.

2016-02-01

To address the data review burden and improve the reliability of the ultrasonic inspection of large composite structures, automated data analysis (ADA) algorithms have been developed to make calls on indications that satisfy the detection criteria and minimize false calls. The original design followed standard procedures for analyzing signals for time-of-flight indications and backwall amplitude dropout. However, certain complex panels with varying shape, ply drops and the presence of bonds can complicate this interpretation process. In this paper, enhancements to the automated data analysis algorithms are introduced to address these challenges. To estimate the thickness of the part and presence of bonds without prior information, an algorithm tracks potential backwall or bond-line signals, and evaluates a combination of spatial, amplitude, and time-of-flight metrics to identify bonded sections. Once part boundaries, thickness transitions and bonded regions are identified, feature extraction algorithms are applied to multiple sets of through-thickness and backwall C-scan images, for evaluation of both first layer through thickness and layers under bonds. ADA processing results are presented for a variety of complex test specimens with inserted materials and other test discontinuities. Lastly, enhancements to the ADA software interface are presented, which improve the software usability for final data review by the inspectors and support the certification process.

Exploring the Potential of In-Service Training through Distance Education.

ERIC Educational Resources Information Center

Kelsey, Timothy W.; Mincemoyer, Claudia C.

2001-01-01

Survey responses from 228 Pennsylvania extension staff revealed time- or travel-related reasons inhibited inservice participation. They preferred regional locations over any other, though they were receptive to having some inservice programs delivered using distance education technologies. A pilot test of quarterly satellite inservice programs was…

Positioning challenges in reconfigurable semi-autonomous robotic NDE inspection

NASA Astrophysics Data System (ADS)

Pierce, S. Gareth; Dobie, Gordon; Summan, Rahul; Mackenzie, Liam; Hensman, James; Worden, Keith; Hayward, Gordon

2010-03-01

This paper describes work conducted into mobile, wireless, semi-autonomous NDE inspection robots developed at The University of Strathclyde as part of the UK Research Centre for Non Destructive Evaluation (RCNDE). The inspection vehicles can incorporate a number of different NDE payloads including ultrasonic, eddy current, visual and magnetic based payloads, and have been developed to try and improve NDE inspection techniques in challenging inspection areas (for example oil, gas, and nuclear structures). A significant research challenge remains in the accurate positioning and guidance of such vehicles for real inspection tasks. Employing both relative and absolute position measurements, we discuss a number of approaches to position estimation including Kalman and particle filtering. Using probabilistic approaches enables a common mathematical framework to be employed for both positioning and data fusion from different NDE sensors. In this fashion the uncertainties in both position and defect identification and classification can be dealt with using a consistent approach. A number of practical constraints and considerations to different precision positioning techniques are discussed, along with NDE applications and the potential for improved inspection capabilities by utilising the inherent reconfigurable capabilities of the inspection vehicles.

Detection of fastener loosening in simple lap joint based on ultrasonic wavefield imaging

NASA Astrophysics Data System (ADS)

Gooda Sahib, M. I.; Leong, S. J.; Chia, C. C.; Mustapha, F.

2017-12-01

Joints in aero-mechanical structures are critical elements that ensure the structural integrity but they are prone to damages. Inspection of such joints that have no prior baseline data is really challenging but it can be possibly done using the Ultrasonic Propagation Imager (UPI). The feasibility of applying UPI for detection of loosened fastener is investigated in this study. A simple lap joint specimen made by connecting two pieces of 2.5mm thick SAE304 stainless steel plates using five M6 screws and nuts has been used in this study. All fasteners are tightened to 10Nm but one of them is completely loosened to simulate the damage. The wavefield data is processed into ultrasonic wavefield propagation video and a series of spectral amplitude images. The spectral images showed noticeable amplitude difference at the loosened fastener, hence confirmed the feasibility of using UPI for structural joints inspection. A simple contrast maximization method is also introduced to improve the result.

Special Education Inservice Priorities for Regular Educators.

ERIC Educational Resources Information Center

Bass, Michele Britton

To identify content and format priorities for special education inservice training, 243 elementary classroom teachers in 21 schools with learning handicapped (LH) programs were surveyed. A questionnaire was developed to elicit responses to 22 topics and 21 methods of inservice training, with category selection based on a Likert-type one to four…

What Variables Appear Important in Changing Traditional Inservice Training Procedures.

ERIC Educational Resources Information Center

Sobol, Francis Thomas

Herein are discussed descriptive findings from the educational literature on the question of what variables appear important in changing traditional in-service training procedures. The question of the content versus the process of in-service training, important problems in in-service training programs, and implications of the important problems…

Techniques and software tools for estimating ultrasonic signal-to-noise ratios

NASA Astrophysics Data System (ADS)

Chiou, Chien-Ping; Margetan, Frank J.; McKillip, Matthew; Engle, Brady J.; Roberts, Ronald A.

2016-02-01

At Iowa State University's Center for Nondestructive Evaluation (ISU CNDE), the use of models to simulate ultrasonic inspections has played a key role in R&D efforts for over 30 years. To this end a series of wave propagation models, flaw response models, and microstructural backscatter models have been developed to address inspection problems of interest. One use of the combined models is the estimation of signal-to-noise ratios (S/N) in circumstances where backscatter from the microstructure (grain noise) acts to mask sonic echoes from internal defects. Such S/N models have been used in the past to address questions of inspection optimization and reliability. Under the sponsorship of the National Science Foundation's Industry/University Cooperative Research Center at ISU, an effort was recently initiated to improve existing research-grade software by adding graphical user interface (GUI) to become user friendly tools for the rapid estimation of S/N for ultrasonic inspections of metals. The software combines: (1) a Python-based GUI for specifying an inspection scenario and displaying results; and (2) a Fortran-based engine for computing defect signal and backscattered grain noise characteristics. The latter makes use of several models including: the Multi-Gaussian Beam Model for computing sonic fields radiated by commercial transducers; the Thompson-Gray Model for the response from an internal defect; the Independent Scatterer Model for backscattered grain noise; and the Stanke-Kino Unified Model for attenuation. The initial emphasis was on reformulating the research-grade code into a suitable modular form, adding the graphical user interface and performing computations rapidly and robustly. Thus the initial inspection problem being addressed is relatively simple. A normal-incidence pulse/echo immersion inspection is simulated for a curved metal component having a non-uniform microstructure, specifically an equiaxed, untextured microstructure in which the average

In-service education and training as experienced by registered nurses.

PubMed

Norushe, T F; Van Rooyen, D; Strumpher, J

2004-11-01

Nursing is a dynamic profession that is subject to rapid changes in health care provision, hence the need for in-service training programmes for nurses. Newly employed registered nurses require in-service training in order to update them regarding the latest developments in nursing practice. The researcher noted that some newly appointed registered nurses were not competent in all aspects relating to their tasks. This could have been due to a knowledge deficit relating to either new developments or of the procedure relating to a specific task. In some institutions newly-appointed registered nurses on probation reported not receiving in-service training for six months or longer, yet they were still expected to perform their tasks efficiently. The objectives of the study were to, firstly, explore and describe the experiences of registered nurses regarding in-service training programmes in their institutions and, secondly, to make recommendations to Nursing Service Managers relating to the development of effective in-service training programmes in their institutions. A qualitative, exploratory, descriptive design was implemented. Data was analysed using Tesch's descriptive approach (in Creswell, 1994:155). Two main themes emerged, namely that registered nurses experienced in-service training programmes as inadequate and reacted negatively towards them. This article focuses on the experiences of registered nurses relating to in-service training programmes, as well as the formulation of guidelines to assist nursing service managers in the development of effective in-service training programmes.

Ultrasonic sensor based defect detection and characterisation of ceramics.

PubMed

Kesharaju, Manasa; Nagarajah, Romesh; Zhang, Tonzhua; Crouch, Ian

2014-01-01

Ceramic tiles, used in body armour systems, are currently inspected visually offline using an X-ray technique that is both time consuming and very expensive. The aim of this research is to develop a methodology to detect, locate and classify various manufacturing defects in Reaction Sintered Silicon Carbide (RSSC) ceramic tiles, using an ultrasonic sensing technique. Defects such as free silicon, un-sintered silicon carbide material and conventional porosity are often difficult to detect using conventional X-radiography. An alternative inspection system was developed to detect defects in ceramic components using an Artificial Neural Network (ANN) based signal processing technique. The inspection methodology proposed focuses on pre-processing of signals, de-noising, wavelet decomposition, feature extraction and post-processing of the signals for classification purposes. This research contributes to developing an on-line inspection system that would be far more cost effective than present methods and, moreover, assist manufacturers in checking the location of high density areas, defects and enable real time quality control, including the implementation of accept/reject criteria. Copyright © 2013 Elsevier B.V. All rights reserved.

Automated robotic equipment for ultrasonic inspection of pressurizer heater wells

DOEpatents

Nachbar, Henry D.; DeRossi, Raymond S.; Mullins, Lawrence E.

1993-01-01

A robotic device for remotely inspecting pressurizer heater wells is provided which has the advantages of quickly, precisely, and reliably acquiring data at reasonable cost while also reducing radiation exposure of an operator. The device comprises a prober assembly including a probe which enters a heater well, gathers data regarding the condition of the heater well and transmits a signal carrying that data; a mounting device for mounting the probe assembly at the opening of the heater well so that the probe can enter the heater well; a first motor mounted on the mounting device for providing movement of the probe assembly in an axial direction; and a second motor mounted on the mounting device for providing rotation of the probe assembly. This arrangement enables full inspection of the heater well to be carried out.

Evaluation of an In-service Course on Biotechnology.

ERIC Educational Resources Information Center

Lock, Roger; Dunkerton, John

1989-01-01

Described is the evaluation of an inservice course on biotechnology. Evaluated were the influence that the course had on teacher knowledge, use of practical work, problem solving investigations and theoretical aspects of biotechnology. A practical model of inservice evaluation is provided. (Author/CW)

Application of Ultrasonic Phased Array Technology to the Detection of Defect in Composite Stiffened-structures

NASA Astrophysics Data System (ADS)

Zhou, Yuan-Qi; Zhan, Li-Hua

2016-05-01

Composite stiffened-structure consists of the skin and stringer has been widely used in aircraft fuselage and wings. The main purpose of the article is to detect the composite material reinforced structure accurately and explore the relationship between defect formation and structural elements or curing process. Based on ultrasonic phased array inspection technology, the regularity of defects in the manufacture of composite materials are obtained, the correlation model between actual defects and nondestructive testing are established. The article find that the forming quality of deltoid area in T-stiffened structure is obviously improved by pre-curing, the defects of hat-stiffened structure are affected by the mandrel. The results show that the ultrasonic phased array inspection technology can be an effectively way for the detection of composite stiffened-structures, which become an important means to control the defects of composite and improve the quality of the product.

The Detection of Burn-Through Weld Defects Using Noncontact Ultrasonics

PubMed Central

Abbasi, Zeynab; Yuhas, Donald; Zhang, Lu; Basantes, Alexandra-Del-Carmen; Tehrani, Niloofar Nabili; Ozevin, Didem; Indacochea, Ernesto

2018-01-01

Nearly all manufactured products in the metal industry involve welding. The detection and correction of defects during welding improve the product reliability and quality, and prevent unexpected failures. Nonintrusive process control is critical for avoiding these defects. This paper investigates the detection of burn-through damage using noncontact, air-coupled ultrasonics, which can be adapted to the immediate and in-situ inspection of welded samples. The burn-through leads to a larger volume of degraded weld zone, providing a resistance path for the wave to travel which results in lower velocity, energy ratio, and amplitude. Wave energy dispersion occurs due to the increase of weld burn-through resulting in higher wave attenuation. Weld sample micrographs are used to validate the ultrasonic results. PMID:29342875

Inservice Teacher Education in Nigeria: A Case Study.

ERIC Educational Resources Information Center

Esu, Akon E. O.

1991-01-01

Examines the current status of in-service teacher education in Nigeria, indicating three approaches: the central office approach; the long vacation program; and the Associateship Certificate in Education distance learning approach. Recommendations for planning and implementing in-service teacher education programs in Nigeria are noted. (SM)

The Information-Seeking Habits of In-Service Educators

ERIC Educational Resources Information Center

Shipman, Todd; Bannon, Susan H.; Nunes-Bufford, Kimberly

2015-01-01

Research on information literacy and educators has focused on preservice educators and learning information literacy skills. Little research exists on in-service educators and their information literacy skills. Purposes of this study were to identify information sources that in-service educators used; to determine relationships between information…

Investigate Fundamentals and Performance Improvements of Current In-Line Inspection Technologies for Mechanical Damage Detection

DOT National Transportation Integrated Search

2008-05-01

This Phase I report provides a comprehensive and in-depth review of the current status of in-line inspection technologies, including, but not limited to, Magnetic (Axial MFL, Circumferential MFL), Ultrasonic (UT), and Geometrical (Caliper) methods, i...

Evaluation of ultrasonics and optimized radiography for 2219-T87 aluminum weldments

NASA Technical Reports Server (NTRS)

Clotfelter, W. N.; Hoop, J. M.; Duren, P. C.

1975-01-01

Ultrasonic studies are described which are specifically directed toward the quantitative measurement of randomly located defects previously found in aluminum welds with radiography or with dye penetrants. Experimental radiographic studies were also made to optimize techniques for welds of the thickness range to be used in fabricating the External Tank of the Space Shuttle. Conventional and innovative ultrasonic techniques were applied to the flaw size measurement problem. Advantages and disadvantages of each method are discussed. Flaw size data obtained ultrasonically were compared to radiographic data and to real flaw sizes determined by destructive measurements. Considerable success was achieved with pulse echo techniques and with 'pitch and catch' techniques. The radiographic work described demonstrates that careful selection of film exposure parameters for a particular application must be made to obtain optimized flaw detectability. Thus, film exposure techniques can be improved even though radiography is an old weld inspection method.

Commercial Implementation of Ultrasonic Velocity Imaging Methods via Cooperative Agreement Between NASA Lewis Research Center and Sonix, Inc.

NASA Technical Reports Server (NTRS)

Roth, Don J.; Hendricks, J. Lynne; Whalen, Mike F.; Bodis, James R.; Martin, Katherine

1996-01-01

This article describes the commercial implementation of ultrasonic velocity imaging methods developed and refined at NASA Lewis Research Center on the Sonix c-scan inspection system. Two velocity imaging methods were implemented: thickness-based and non-thickness-based reflector plate methods. The article demonstrates capabilities of the commercial implementation and gives the detailed operating procedures required for Sonix customers to achieve optimum velocity imaging results. This commercial implementation of velocity imaging provides a 100x speed increase in scanning and processing over the lab-based methods developed at LeRC. The significance of this cooperative effort is that the aerospace and other materials development-intensive industries which use extensive ultrasonic inspection for process control and failure analysis will now have an alternative, highly accurate imaging method commercially available.

A novel ultrasonic phased array inspection system to NDT for offshore platform structures

NASA Astrophysics Data System (ADS)

Wang, Hua; Shan, Baohua; Wang, Xin; Ou, Jinping

2007-01-01

A novel ultrasonic phased array detection system is developed for nondestructive testing (NDT). The purpose of the system is to make acquisition of data in real-time from 64-element ultrasonic phased array transducer, and to enable real- time processing of the acquired data. The system is composed of five main parts: master unit, main board, eight transmit/receive units, a 64-element transducer and an external PC. The system can be used with 64 element transducers, excite 32 elements, receive and sample echo signals form 32 elements simultaneously at 62.5MHz with 8 bit precision. The external PC is used as the user interface showing the real time images and controls overall operation of the system through USB serial link. The use of Universal Serial Bus (USB) improves the transform speed and reduces hardware interface complexity. The program of the system is written in Visual C++.NET and is platform independent.

Monitoring bolt torque levels through signal processing of full-field ultrasonic data

NASA Astrophysics Data System (ADS)

Haynes, Colin; Yeager, Michael; Todd, Michael; Lee, Jung-Ryul

2014-03-01

Using full-field ultrasonic guided wave data can provide a wealth of information on the state of a structure through a detailed characterization of its wave propagation properties. However, the need for appropriate feature selection and quantified metrics for making rigorous assessments of the structural state is in no way lessened by the density of information. In this study, a simple steel bolted connection with two bolts is monitored for bolt loosening. The full-field data were acquired using a scanning-laser-generated ultrasound system with a single surface-mounted sensor. Such laser systems have many advantages that make them attractive for nondestructive evaluation, including their high-speed, high spatial resolution, and the ability to scan large areas of in-service structures. In order to characterize the relationship between bolt torque and the resulting wavefield in this specimen, the bolt torque in each of the bolts is independently varied from fully tightened to fully loosened in several steps. First, qualitative observations about the changes in the wavefield are presented. Next, an approach to quantifying the wave transmission through the bolted joint is discussed. Finally, a method of monitoring the bolt torque using the ultrasonic data is demonstrated.

Technology Integration Support Levels for In-Service Teachers

ERIC Educational Resources Information Center

Williams, Mable Evans

2017-01-01

In-service teachers across the globe are expected to integrate technology in their respective instructional content area. The purpose of this qualitative study was to explore the perceptions of in-service teachers concerning building-level support for technology integration. Participants in the study were asked to participate in semi-structured…

Rapid non-contact inspection of composite ailerons using air-coupled ultrasound

NASA Astrophysics Data System (ADS)

Panda, Rabi Sankar; Karpenko, Oleksii; Udpa, Lalita; Haq, Mahmoodul; Rajagopal, Prabhu; Balasubramaniam, Krishnan

2016-02-01

This paper demonstrates an approach for rapid non-contact air-coupled ultrasonic inspection of composite ailerons with complex cross-sectional profile including thickness changes, curvature and the presence of a number of stiffeners. Low-frequency plate guided ultrasonic modes are used in B-scan mode for the measurements in pitch-catch mode. Appropriate probe holder angles suitable for generating and receiving lower order guided wave modes are discussed. Different embodiments of the pitch-catch tandem positions along and across stiffener and curved regions of the test sample enable a rapid test campaign capturing the feature-rich sample profile. Techniques to distinguish special features in the stiffener are presented.

Robotic inspection of fiber reinforced composites using phased array UT

NASA Astrophysics Data System (ADS)

Stetson, Jeffrey T.; De Odorico, Walter

2014-02-01

Ultrasound is the current NDE method of choice to inspect large fiber reinforced airframe structures. Over the last 15 years Cartesian based scanning machines using conventional ultrasound techniques have been employed by all airframe OEMs and their top tier suppliers to perform these inspections. Technical advances in both computing power and commercially available, multi-axis robots now facilitate a new generation of scanning machines. These machines use multiple end effector tools taking full advantage of phased array ultrasound technologies yielding substantial improvements in inspection quality and productivity. This paper outlines the general architecture for these new robotic scanning systems as well as details the variety of ultrasonic techniques available for use with them including advances such as wide area phased array scanning and sound field adaptation for non-flat, non-parallel surfaces.

[Development of a system for ultrasonic three-dimensional reconstruction of fetus].

PubMed

Baba, K

1989-04-01

We have developed a system for ultrasonic three-dimensional (3-D) fetus reconstruction using computers. Either a real-time linear array probe or a convex array probe of an ultrasonic scanner was mounted on a position sensor arm of a manual compound scanner in order to detect the position of the probe. A microcomputer was used to convert the position information to what could be recorded on a video tape as an image. This image was superimposed on the ultrasonic tomographic image simultaneously with a superimposer and recorded on a video tape. Fetuses in utero were scanned in seven cases. More than forty ultrasonic section image on the video tape were fed into a minicomputer. The shape of the fetus was displayed three-dimensionally by means of computer graphics. The computer-generated display produced a 3-D image of the fetus and showed the usefulness and accuracy of this system. Since it took only a few seconds for data collection by ultrasonic inspection, fetal movement did not adversely affect the results. Data input took about ten minutes for 40 slices, and 3-D reconstruction and display took about two minutes. The system made it possible to observe and record the 3-D image of the fetus in utero non-invasively and therefore is expected to make it much easier to obtain a 3-D picture of the fetus in utero.

The Center for In-Service Education. Final Evaluation Report. Volume I. Part 1.

ERIC Educational Resources Information Center

Tennessee State Dept. of Education, Nashville.

The primary objectives of the Center for In-Service Education in implementing a model for in-service education were to a) implement and demonstrate the comprehensive in-service model developed during the planning phase, b) provide coordinated planning of in-service education for all participating school systems, c) directly assist regional…

Measurement and Modeling of Ultrasonic Pitch/catch Grain Noise

NASA Astrophysics Data System (ADS)

Margetan, F. J.; Gray, T. A.; Thompson, R. B.

2008-02-01

Ultrasonic grain noise arises from the scattering of sound waves by microstructural boundaries, and can limit the detection of weakly-reflecting internal defects in metals. In some cases of practical interest, such as focused-transducer inspections of aircraft engine components, so-called "single scattering" or "independent scatterer" models have proven to be reasonably accurate in predicting grain noise characteristics. In pulse/echo inspections it is difficult to experimentally assess the relative contributions of single scattering and multiple scattering, because both can generally contribute to the backscattered noise seen at any given observation time. For pitch/catch inspections, however, it is relatively easy to construct inspection geometries for which single-scattered noise should be insignificant, and hence any observed noise is presumably due to multiple scattering. This concept is demonstrated using pitch/catch shear-wave measurements performed on a well-characterized stainless-steel specimen. The inspection geometry allows us to control the overlap volume of the intersecting radiation fields of the two transducers. As we proceed from maximally overlapping fields to zero overlap, the single-scattering contribution to the observed grain noise is expected to decrease. Measurements are compared to the predictions of a single-scatterer model, and the relative contributions of single and multiple scattering to the observed grain noise are estimated.

49 CFR 214.529 - In-service failure of primary braking system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway maintenance...

49 CFR 214.529 - In-service failure of primary braking system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway maintenance...

49 CFR 214.529 - In-service failure of primary braking system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway maintenance... 49 Transportation 4 2010-10-01 2010-10-01 false In-service failure of primary braking system. 214...

RITES: Online (Reaching In-service Teachers with Earth Sciences Online)

NASA Astrophysics Data System (ADS)

Baptiste, H.

2003-12-01

The RITES: Online project team (Drs. H. Prentice Baptiste, Susan Brown, Jennifer Villa) believed that the power of technology could not be effectively utilized unless it was grounded in new models of teaching and learning based on a student centered and project based curriculum, that increased opportunities for active, hands-on learning and respect for multiculturalism. We subscribe to an inquiry approach to learning. Specifically, science teaching should actively engage the learners in activities that draw on multiple abilities and learning styles. Recent brain-based research has shown that human beings construct knowledge through actions and interactions within their environment. Learning occurs in communities, and new ideas are linked to previous knowledge and constructed by the learner. Knowledge is acquired by making connections. We believed the aforementioned ideas and points to be equally true for the teacher candidates and inservice teachers participating in the RITES: Online project as well as for their students. The ESSEA science courses were delivered by distance learning via the university WebCt distance education system to teacher candidates (preservice teachers) and inservice teachers. Teacher candidates and inservice teachers were encouraged to use technology when involving their students in science inquiry activities and to record their students' involvement in science activities with digital cameras. Teacher candidates and inservice teachers involve in the ESSEA courses are engaged in earth science inquiry activities relevant to the four spheres (atmosphere, lithosphere, biosphere, hydrosphere) with the students in their classes. This presentation will highlight teacher candidates and inservice teachers in the roles of designer, researcher, and collaborator. Examples of student works will also be a part of the Power point presentation. As a result of our courses our teachers have attained the following positive outcomes: 1) Teacher candidates and

Ultrasonic guided wave bondline evaluation of thick metallic structures with viscoelastic coatings and the demonstration of a novel mode sweep technique

NASA Astrophysics Data System (ADS)

Bostron, Jason

Ultrasonic guided waves are becoming more widely used in nondestructive evaluation applications due to their efficiency in defect detection, ability to inspect hidden areas, and other reasons. This dissertation addresses two main topics: ultrasonic guided wave bond evaluation of thin and thick coatings on thick metallic structures, and the use of a novel phased array technique for optimal guided wave mode and frequency selection. (Abstract shortened by UMI.).

Teacher-Designed Reform in Inservice Education. Final Report.

ERIC Educational Resources Information Center

Edelfelt, Roy A.; And Others

This is the final report of the project on Teacher-Designed Reform in Teacher Education. The focus of the project was primarily on inservice education to improve instruction. The rationale was that teachers should determine the content and design of inservice education at the school building level on the basis of the kind of staff they want and…

NDT applications in a successful fracture critical bridge inspection program and anchor bolt inspection program

NASA Astrophysics Data System (ADS)

Fish, Philip E.

1995-05-01

In 1978, Wisconsin Department of Transportation discovered major cracking on a two-girder, fracture critical structure, just four years after it was constructed. In 1981, on the same structure, now seven years old, major cracking was discovered in the tie girder flange of the tied arch span. This is one example of the type of failures that transportation departments discovered on welded structures in the 1970's and '80's. The failures from welded details and pinned connections lead to much stricter standards for present day designs. All areas were affected: design with identification of fatigue-prone details and classification of fatigue categories; material requirements with emphasis on toughness and weldability; increased welding and fabrication standards with licensure of fabrication shops to minimum quality standards including personnel; and an increased effort on inspection of existing bridges, where critical details were overlooked or missed in the past. FHWA inspection requirements for existing structures increased through this same time period, in reaction to the failures that had occurred. Obviously, many structures in Wisconsin were not built to the standards now required, thus the importance for quality inspection techniques. The new FHWA inspection requirements now being implemented throughout the nation require an in-depth, hands-on type inspection at a specified frequency, on all fracture critical structures. Wisconsin Department of Transportation started an in-depth inspection program in 1985 and made it a full time program in 1987. This program included extensive nondestructive testing. Ultrasonic inspection has played a major role in this type of inspection. All fracture critical structures, pin and hanger systems, and pinned connections are inspected on a five-year cycle now. The program requires an experienced inspection team and a practical inspection approach. Extensive preparation is required with review of all design, construction, and

Procedure to establish inspection intervals of regularity maintained in-service units subject to failure

DOT National Transportation Integrated Search

1996-05-01

Procedures have been developed for determining the period between regular inspections that is required to ensure, with a : specified level of confidence, that no more than a certain percentage of the units of a population that is in service is : fail...

Ultrasonic inspection of a glued laminated timber fabricated with defects

Treesearch

Robert Emerson; David Pollock; David McLean; Kenneth Fridley; Robert Ross; Roy Pellerin

2001-01-01

The Federal Highway Administration (FHWA) set up a validation test to compare the effectiveness of various nondestructive inspection techniques for detecting artificial defects in glulam members. The validation test consisted of a glulam beam fabricated with artificial defects known to FHWA personnel but not originally known to the scientists performing the validation...

Scanning of the internal structure part with laser ultrasonic in aviation industry.

PubMed

Swornowski, Pawel J

2011-01-01

The detection of internal defects is a major production and safety issue for the newest generations of aircraft. New materials and manufacturing processes in the aircraft industry demand efficient quality assurance in manufacturing and inspection in maintenance. Advanced metallic material processes (titanium) are used or developed for the production of heavily loaded flying components (in fan blade construction). The inspection of these parts mainly made out of titanium (or CFRP) requires the determination of the percentage of bonded grain sizes around 10-30 µm. This is primarily due to the advantages of a high signal-to-noise ratio and good detection sensitivity. In this article, a diagnosing method of the blade interior by means of the laser ultrasonic is presented. Identification of small fatigue cracks presents a challenging problem during nondestructive testing of fatigue-damaged structures. Laser ultrasonic is a technique that uses two laser beams; one with a short pulse for the generation of ultrasound and another with a long pulse or continuous coupled to an optical interferometer for detection. The results of research of the internal blade structure are presented. Copyright © 2011 Wiley Periodicals, Inc.

In-Service Science Teachers' Attitude towards Information Communication Technology

ERIC Educational Resources Information Center

Kibirige, I.

2011-01-01

The purpose of this study is to determine the attitude of in-service science teachers towards information communication technology (ICT) in education. The study explores the relationship between in-service teachers and four independent variables: their attitudes toward computers; their cultural perception of computers; their perceived computer…

Study of ultrasonic thermometry based on ultrasonic time-of-flight measurement

NASA Astrophysics Data System (ADS)

Jia, Ruixi; Xiong, Qingyu; Wang, Lijie; Wang, Kai; Shen, Xuehua; Liang, Shan; Shi, Xin

2016-03-01

Ultrasonic thermometry is a kind of acoustic pyrometry and it has been evolving as a new temperature measurement technology for various environment. However, the accurate measurement of the ultrasonic time-of-flight is the key for ultrasonic thermometry. In this paper, we study the ultrasonic thermometry technique based on ultrasonic time-of-flight measurement with a pair of ultrasonic transducers for transmitting and receiving signal. The ultrasonic transducers are installed in a single path which ultrasonic travels. In order to validate the performance of ultrasonic thermometry, we make a contrast about the absolute error between the measured temperature value and the practical one. With and without heater source, the experimental results indicate ultrasonic thermometry has high precision of temperature measurement.

Characterization of Delaminations and Transverse Matrix Cracks in Composite Laminates Using Multiple-Angle Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Johnston, Patrick H.; Appleget, Chelsea D.; Odarczenko, Michael T.

2012-01-01

Delaminations and transverse matrix cracks often appear concurrently in composite laminates. Normal-incidence ultrasound is excellent at detecting delaminations, but is not optimum for matrix cracks. Non-normal incidence, or polar backscattering, has been shown to optimally detect matrix cracks oriented perpendicular to the ultrasonic plane of incidence. In this work, a series of six composite laminates containing slots were loaded in tension to achieve various levels of delamination and ply cracking. Ultrasonic backscattering was measured over a range of incident polar and azimuthal angles, in order to characterize the relative degree of damage of the two types. Sweptpolar- angle measurements were taken with a curved phased array, as a step toward an array-based approach to simultaneous measurement of combined flaws.

Inservice Education and the 6 O'Clock News. OSSC Bulletin Vol. 21, No. 7.

ERIC Educational Resources Information Center

Arends, Richard; And Others

Several assumptions currently held by many inservice planners and deliverers are presented and challenged. A new model of inservice programs is outlined that pays attention to the characteristics of maturing and growing professional educators and that demands new forms for delivering inservice to individuals and school clients. Inservice delivery…

Tailoring Inservice Training in Science to Elementary Teachers' Needs.

ERIC Educational Resources Information Center

Bethel, Lowell J.

1982-01-01

Elementary school teachers feel inadequately prepared to teach science and spend little class time on science instruction. Until undergraduate science preparation improves, inservice training must take up the slack. An inservice program developed by the Science Education Center at the University of Texas' College of Education shows positive…

Silicon wafer temperature monitoring using all-fiber laser ultrasonics

NASA Astrophysics Data System (ADS)

Alcoz, Jorge J.; Duffer, Charles E.

1998-03-01

Laser-ultrasonics is a very attractive technique for in-line process control in the semiconductor industry as it is compatible with the clean room environment and offers the capability to inspect parts at high-temperature. We describe measurements of the velocity of laser-generated Lamb waves in silicon wafers as a function of temperature using fiber- optic laser delivery and all-fiber interferometric sensing. Fundamental anti-symmetric Lamb-wave modes were generated in 5 inches < 111 > silicon wafers using a Nd:YAG laser coupled to a large-core multimode fiber. Generation was also performed using an array of sources created with a diffraction grating. For detection a compact fiber-optic sensor was used which is well suited for industrial environments as it is compact, rugged, stable, and low-cost. The wafers were heated up to 1000 degrees C and the temperature correlated with ultrasonic velocity measurements.

Participant Perceptions of the Quality of In-Service Programs.

ERIC Educational Resources Information Center

Reardon, Francis J.

A survey was taken to elicit participants' perceptions of the quality of inservice courses in Pennsylvania. The 610 respondents represented a wide variety of school districts and inservice programs and were made up primarily of teachers, although nurses and administrators responded as well. The responses indicated very strongly that inservice…

Data fusion for automated non-destructive inspection

PubMed Central

Brierley, N.; Tippetts, T.; Cawley, P.

2014-01-01

In industrial non-destructive evaluation (NDE), it is increasingly common for data acquisition to be automated, driving a recent substantial increase in the availability of data. The collected data need to be analysed, typically necessitating the painstaking manual labour of a skilled operator. Moreover, in automated NDE a region of an inspected component is typically interrogated several times, be it within a single data channel due to multiple probe passes, across several channels acquired simultaneously or over the course of repeated inspections. The systematic combination of these diverse readings is recognized to offer an opportunity to improve the reliability of the inspection, but is not achievable in a manual analysis. This paper describes a data-fusion-based software framework providing a partial automation capability, allowing component regions to be declared defect-free to a very high probability while readily identifying defect indications, thereby optimizing the use of the operator's time. The system is designed to applicable to a wide range of automated NDE scenarios, but the processing is exemplified using the industrial ultrasonic immersion inspection of aerospace turbine discs. Results obtained for industrial datasets demonstrate an orders-of-magnitude reduction in false-call rates, for a given probability of detection, achievable using the developed software system. PMID:25002828

Proceedings of the symposium on inservice testing of pumps and valves

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

Not Available

1990-10-01

The 1990 Symposium on Inservice Testing of Pumps and Valves, jointly sponsored by the Board on Nuclear Codes and Standards of the American Society of Mechanical Engineers and by the Nuclear Regulatory Commission, provided a forum for the discussion of current programs and methods for inservice testing at nuclear power plants. The symposium also provided an opportunity to discuss the need to improve inservice testing in order to ensure the reliable performance of pumps and valves. The participation of industry representatives, regulators, and consultants resulted in the discussion of a broad spectrum of ideas and perspectives regarding the improvement ofmore » inservice testing of pumps and valves at nuclear power plants.« less

Institutional Roles for In-Service Education of School Administrators.

ERIC Educational Resources Information Center

Lynch, Patrick D., Ed.; Blackstone, Peggy L., Ed.

This document is a compilation of papers read at a 4-day conference attended by 60 participants from throughout the United States. Chapters include (1) "In-Service Education of School Administrators: Background, Present Status, and Problems," by Robert B. Howsam; (2) "Notes on Institutional Relationships in the In-Service Education of the…

Opinions of Inservice Experts.

ERIC Educational Resources Information Center

King, Vera R.; Hahn, Margaret

Two hundred and twenty-five inservice experts (administrators, counselors, teachers, and curriculum specialists) from 15 school districts were surveyed, and their opinions used in planning an improved mathematics education teacher preparation program at a Texas university. Results of the survey indicate that although most of the parties felt…

Ultrasonic pulser-receiver

DOEpatents

Taylor, Steven C.

2006-09-12

Ultrasonic pulser-receiver circuitry, for use with an ultrasonic transducer, the circuitry comprising a circuit board; ultrasonic pulser circuitry supported by the circuit board and configured to be coupled to an ultrasonic transducer and to cause the ultrasonic transducer to emit an ultrasonic output pulse; receiver circuitry supported by the circuit board, coupled to the pulser circuitry, including protection circuitry configured to protect against the ultrasonic pulse and including amplifier circuitry configured to amplify an echo, received back by the transducer, of the output pulse; and a connector configured to couple the ultrasonic transducer directly to the circuit board, to the pulser circuitry and receiver circuitry, wherein impedance mismatches that would result if the transducer was coupled to the circuit board via a cable can be avoided.

Safety assessment for In-service Pressure Bending Pipe Containing Incomplete Penetration Defects

NASA Astrophysics Data System (ADS)

Wang, M.; Tang, P.; Xia, J. F.; Ling, Z. W.; Cai, G. Y.

2017-12-01

Incomplete penetration defect is a common defect in the welded joint of pressure pipes. While the safety classification of pressure pipe containing incomplete penetration defects, according to periodical inspection regulations in present, is more conservative. For reducing the repair of incomplete penetration defect, a scientific and applicable safety assessment method for pressure pipe is needed. In this paper, the stress analysis model of the pipe system was established for the in-service pressure bending pipe containing incomplete penetration defects. The local finite element model was set up to analyze the stress distribution of defect location and the stress linearization. And then, the applicability of two assessment methods, simplified assessment and U factor assessment method, to the assessment of incomplete penetration defects located at pressure bending pipe were analyzed. The results can provide some technical supports for the safety assessment of complex pipelines in the future.

The State of the Art in Inservice Education. A Review of the Literature.

ERIC Educational Resources Information Center

Cooper, Carol M.; Jones, Edward V.

This monograph reviews the literature pertaining to inservice education and summarizes its contents relating to several broad themes: planning and instructional concerns in inservice education, problems relating to administration and coordination of inservice programs, and elements common to successful programs. The literature of inservice…

Assessment of weld quality of aerospace grade metals by using ultrasonic matrix phased array technology

NASA Astrophysics Data System (ADS)

Na, Jeong K.; Gleeson, Sean T.

2014-03-01

Advantages of two dimensional electronic ultrasonic beam focusing, steering and scanning with the matrix phased array (MPA) technology has been used to visualize the conditions of resistance spot welds in auto vehicle grade advanced high strength steel carbon steels nondestructively. Two of the commonly used joining techniques, resistance spot welding and resistance seam welding, for thin aerospace grade plates made of aluminum, titanium, and stainless steels have also been inspected with the same MPA NDE system. In this study, a detailed discussions of the current MPA based ultrasonic real time imaging methodology has been made followed by some of the NDT results obtained with various welded test coupons.

A Leadership Model for University Geology Department Teacher Inservice Programs.

ERIC Educational Resources Information Center

Sheldon, Daniel S.; And Others

1983-01-01

Provides geology departments and science educators with a leadership model for developing earth science inservice programs. Model emphasizes cooperation/coordination among departments, science educators, and curriculum specialists at local/intermediate/state levels. Includes rationale for inservice programs and geology department involvement in…

On-loom, real-time, noncontact detection of fabric defects by ultrasonic imaging.

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

Chien, H. T.

1998-09-08

A noncontact, on-loom ultrasonic inspection technique was developed for real-time 100% defect inspection of fabrics. A prototype was built and tested successfully on loom. The system is compact, rugged, low cost, requires minimal maintenance, is not sensitive to fabric color and vibration, and can easily be adapted to current loom configurations. Moreover, it can detect defects in both the pick and warp directions. The system is capable of determining the size, location, and orientation of each defect. To further improve the system, air-coupled transducers with higher efficiency and sensitivity need to be developed. Advanced detection algorithms also need to bemore » developed for better classification and categorization of defects in real-time.« less

Development of an ultrasonic nondestructive inspection method for impact damage detection in composite aircraft structures

NASA Astrophysics Data System (ADS)

Capriotti, M.; Kim, H. E.; Lanza di Scalea, F.; Kim, H.

2017-04-01

High Energy Wide Area Blunt Impact (HEWABI) due to ground service equipment can often occur in aircraft structures causing major damages. These Wide Area Impact Damages (WAID) can affect the internal components of the structure, hence are usually not visible nor detectable by typical one-sided NDE techniques and can easily compromise the structural safety of the aircraft. In this study, the development of an NDI method is presented together with its application to impacted aircraft frames. The HEWABI from a typical ground service scenario has been previously tested and the desired type of damages have been generated, so that the aircraft panels could become representative study cases. The need of the aircraft industry for a rapid, ramp-friendly system to detect such WAID is here approached with guided ultrasonic waves (GUW) and a scanning tool that accesses the whole structure from the exterior side only. The wide coverage of the specimen provided by GUW has been coupled to a differential detection approach and is aided by an outlier statistical analysis to be able to inspect and detect faults in the challenging composite material and complex structure. The results will be presented and discussed with respect to the detection capability of the system and its response to the different damage types. Receiving Operating Characteristics curves (ROC) are also produced to quantify and assess the performance of the proposed method. Ongoing work is currently aimed at the penetration of the inner components of the structure, such as shear ties and C-frames, exploiting different frequency ranges and signal processing techniques. From the hardware and tool development side, different transducers and coupling methods, such as air-coupled transducers, are under investigation together with the design of a more suitable scanning technique.

An Ultrasonic Wheel-Array Probe

NASA Astrophysics Data System (ADS)

Drinkwater, B. W.; Brotherhood, C. J.; Freemantle, R. J.

2004-02-01

This paper describes the development and modeling of an ultrasonic array wheel probe scanning system. The system operates at 10 MHz using a 64 element array transducer which is 50 mm in length and located in a fluid filled wheel. The wheel is coupled to the test structure dry, or with a small amount of liquid couplant. When the wheel is rolled over the surface of the test structure a defect map (C-Scan) is generated in real-time. The tyre is made from a soft, durable polymer which has very little acoustic loss. Two application studies are presented; the inspection of sealant layers in an aluminum aircraft wing structure and the detection of embedded defects in a thick section carbon composite sample.

Early focus development effort, ultrasonic inspection of fixed housing metal-to-adhesive bondline

NASA Technical Reports Server (NTRS)

Hartmann, John K.; Hoskins, Brad R.; Karner, Paul

1991-01-01

An ultrasonic technique was developed for the fixed housing metal-to-adhesive bondline that will support the Flight 15 time frame and subsequent motors. The technique has the capability to detect a 1.0 inch diameter unbond with a 90 percent probability of detection (POD) at a 95 percent confidence level. The technique and support equipment will perform within the working envelope dictated by a stacked motor configuration.

Thermography Inspection for Early Detection of Composite Damage in Structures During Fatigue Loading

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.; Burke, Eric R.; Parker, F. Raymond; Seebo, Jeffrey P.; Wright, Christopher W.; Bly, James B.

2012-01-01

Advanced composite structures are commonly tested under controlled loading. Understanding the initiation and progression of composite damage under load is critical for validating design concepts and structural analysis tools. Thermal nondestructive evaluation (NDE) is used to detect and characterize damage in composite structures during fatigue loading. A difference image processing algorithm is demonstrated to enhance damage detection and characterization by removing thermal variations not associated with defects. In addition, a one-dimensional multilayered thermal model is used to characterize damage. Lastly, the thermography results are compared to other inspections such as non-immersion ultrasonic inspections and computed tomography X-ray.

In-situ sensory technique for in-service quality monitoring: measurement of the complex Young's modulus of polymers

NASA Astrophysics Data System (ADS)

Zhou, Shunhua; Liang, Chen; Rogers, Craig A.; Sun, Fanping P.; Vick, L.

1993-07-01

Applications of polymeric adhesives in joining different materials have necessitated quantitative health inspection of adhesive joints (coverage, state of cure, adhesive strength, location of voids, etc.). A new in-situ sensory method has been proposed in this paper to inspect the amount and distribution of the critical constituents of polymers and to measure the characteristic parameters (complex Young's modulus and damping). In this technique, ferromagnetic particles have been embedded in a polymeric matrix, similar to a particle- reinforced composite. The dynamic signatures extracted from the tests as a result of magnetic excitation of the embedded ferromagnetic particles are used to evaluate the complex Young's modulus of the host polymers. Moreover, the amplitude of the frequency response is utilized to identify the amount and distribution of embedded particles in polymeric materials or adhesive joints. The results predicted from the theoretical model agree well with the experimental results. The theoretical analyses and the experimental work conducted have demonstrated the utility of the sensory technique presented for in-service health interrogation.

Improving the reliability of automated non-destructive inspection

NASA Astrophysics Data System (ADS)

Brierley, N.; Tippetts, T.; Cawley, P.

2014-02-01

In automated NDE a region of an inspected component is often interrogated several times, be it within a single data channel, across multiple channels or over the course of repeated inspections. The systematic combination of these diverse readings is recognized to provide a means to improve the reliability of the inspection, for example by enabling noise suppression. Specifically, such data fusion makes it possible to declare regions of the component defect-free to a very high probability whilst readily identifying indications. Registration, aligning input datasets to a common coordinate system, is a critical pre-computation before meaningful data fusion takes place. A novel scheme based on a multiobjective optimization is described. The developed data fusion framework, that is able to identify and rate possible indications in the dataset probabilistically, based on local data statistics, is outlined. The process is demonstrated on large data sets from the industrial ultrasonic testing of aerospace turbine disks, with major improvements in the probability of detection and probability of false call being obtained.

Hidden corrosion detection in aircraft aluminum structures using laser ultrasonics and wavelet transform signal analysis.

PubMed

Silva, M Z; Gouyon, R; Lepoutre, F

2003-06-01

Preliminary results of hidden corrosion detection in aircraft aluminum structures using a noncontact laser based ultrasonic technique are presented. A short laser pulse focused to a line spot is used as a broadband source of ultrasonic guided waves in an aluminum 2024 sample cut from an aircraft structure and prepared with artificially corroded circular areas on its back surface. The out of plane surface displacements produced by the propagating ultrasonic waves were detected with a heterodyne Mach-Zehnder interferometer. Time-frequency analysis of the signals using a continuous wavelet transform allowed the identification of the generated Lamb modes by comparison with the calculated dispersion curves. The presence of back surface corrosion was detected by noting the loss of the S(1) mode near its cutoff frequency. This method is applicable to fast scanning inspection techniques and it is particularly suited for early corrosion detection.

The Influence of Reform on Inservice Teacher Education. ERIC Digest.

ERIC Educational Resources Information Center

Abdal-Haqq, Ismat

Recent educational reform efforts have sought to restructure schools, changing the character of school culture and creating a need for a nontraditional approach to inservice teacher education. Inservice projects have been implemented which attempt to prepare practicing teachers for restructured schools and as participants in the restructuring…

Ultrasonic guided wave propagation across waveguide transitions: energy transfer and mode conversion.

PubMed

Puthillath, Padmakumar; Galan, Jose M; Ren, Baiyang; Lissenden, Cliff J; Rose, Joseph L

2013-05-01

Ultrasonic guided wave inspection of structures containing adhesively bonded joints requires an understanding of the interaction of guided waves with geometric and material discontinuities or transitions in the waveguide. Such interactions result in mode conversion with energy being partitioned among the reflected and transmitted modes. The step transition between an aluminum layer and an aluminum-adhesive-aluminum multi-layer waveguide is analyzed as a model structure. Dispersion analysis enables assessment of (i) synchronism through dispersion curve overlap and (ii) wavestructure correlation. Mode-pairs in the multi-layer waveguide are defined relative to a prescribed mode in a single layer as being synchronized and having nearly perfect wavestructure matching. Only a limited number of mode-pairs exist, and each has a unique frequency range. A hybrid model based on semi-analytical finite elements and the normal mode expansion is implemented to assess mode conversion at a step transition in a waveguide. The model results indicate that synchronism and wavestructure matching is associated with energy transfer through the step transition, and that the energy of an incident wave mode in a single layer is transmitted almost entirely to the associated mode-pair, where one exists. This analysis guides the selection of incident modes that convert into transmitted modes and improve adhesive joint inspection with ultrasonic guided waves.

Cultural Immersion for Inservice Teachers: A Model and Some Outcomes.

ERIC Educational Resources Information Center

Mahan, James M.

The Inservice Teacher Cultural Immersion Model of Indiana University has placed 122 inservice teachers in summer graduate practicum positions in distant Native American communities. The model was developed so that teachers can have an innovative and personal experience learning about Native Americans in their own cultural setting. The program…

Ultrasonic pipe assessment

DOEpatents

Thomas, Graham H.; Morrow, Valerie L.; Levie, Harold; Kane, Ronald J.; Brown, Albert E.

2003-12-23

An ultrasonic pipe or other structure assessment system includes an ultrasonic transducer positioned proximate the pipe or other structure. A fluid connection between the ultrasonic transducer and the pipe or other structure is produced. The ultrasonic transducer is moved relative to the pipe or other structure.

Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

NASA Technical Reports Server (NTRS)

Miller, James G.

1995-01-01

In this Progress Report, the author describes the continuing research to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. Images obtained using an unmodified medical ultrasonic imaging system of a bonded aluminum plate sample with a simulated disbond region are presented. The disbond region was produced by adhering a piece of plain white paper to a piece of cellophane tape and applying the paper-tape combination to one of the aluminum plates. Because the area under the paper was not adhesively bonded to the aluminum plate, this arrangement more closely simulates a disbond. Images are also presented for an aluminum plate sample with an epoxy strip adhered to one side to help provide information for the interpretation of the images of the bonded aluminum plate sample containing the disbond region. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to provide information regarding the nature of the disbonded region. The results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology. In Section 2 of this Progress Report, the preparation of the aluminum plate specimens is described. Section 3 describes the method of linear array imaging. Sections 4 and 5 present the linear array images and results from contact transducer measurements, respectively. A discussion of the results are presented in Section 6.

Preservice and Inservice Teachers' Knowledge of Language Constructs in Finland

ERIC Educational Resources Information Center

Aro, Mikko; Björn, Piia Maria

2016-01-01

The aim of the study was to explore the Finnish preservice and inservice teachers' knowledge of language constructs relevant for literacy acquisition. A total of 150 preservice teachers and 74 inservice teachers participated in the study by filling out a questionnaire that assessed self-perceived expertise in reading instruction, knowledge of…

Pre- and In-Service Preschool Teachers' Science Teaching Efficacy Beliefs

ERIC Educational Resources Information Center

Aslan, Durmus; Tas, Isil; Ogul, Irem Gürgah

2016-01-01

In this study, pre- and in-service preschool teachers' science teaching efficacy beliefs were investigated. The sample included 100 pre-service (50 first grades and 50 last grades) and 73 in-service preschool teachers. As a data collection tool "Science Teaching Efficacy Belief Instrument" was used. Findings indicated that in-service…

Scaling up the Single Transducer Thickness-Independent Ultrasonic Imaging Method for Accurate Characterization of Microstructural Gradients in Monolithic and Composite Tubular Structures

NASA Technical Reports Server (NTRS)

Roth, Don J.; Carney, Dorothy V.; Baaklini, George Y.; Bodis, James R.; Rauser, Richard W.

1998-01-01

Ultrasonic velocity/time-of-flight imaging that uses back surface reflections to gauge volumetric material quality is highly suited for quantitative characterization of microstructural gradients including those due to pore fraction, density, fiber fraction, and chemical composition variations. However, a weakness of conventional pulse-echo ultrasonic velocity/time-of-flight imaging is that the image shows the effects of thickness as well as microstructural variations unless the part is uniformly thick. This limits this imaging method's usefulness in practical applications. Prior studies have described a pulse-echo time-of-flight-based ultrasonic imaging method that requires using a single transducer in combination with a reflector plate placed behind samples that eliminates the effect of thickness variation in the image. In those studies, this method was successful at isolating ultrasonic variations due to material microstructure in plate-like samples of silicon nitride, metal matrix composite, and polymer matrix composite. In this study, the method is engineered for inspection of more complex-shaped structures-those having (hollow) tubular/curved geometry. The experimental inspection technique and results are described as applied to (1) monolithic mullite ceramic and polymer matrix composite 'proof-of-concept' tubular structures that contain machined patches of various depths and (2) as-manufactured monolithic silicon nitride ceramic and silicon carbide/silicon carbide composite tubular structures that might be used in 'real world' applications.

Final summary report for 1989 inservice inspection (ISI) of SRS (Savannah River Site) 100-P Reactor tank

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

Morrison, J.M.; Loibl, M.W.

1989-12-15

The integrity of the SRS reactor tanks is a key factor affecting their suitability for continued service since, unlike the external piping system and components, the tanks are virtually irreplaceable. Cracking in various areas of the process water piping systems has occurred beginning in 1960 as a result of several degradation mechanisms, chiefly intergranular stress corrosion cracking (IGSCC) and chloride-induced transgranular cracking. IGSCC, currently the primary degradation mechanism, also occurred in the knuckle'' region (tank wall-to-bottom tube sheet transition piece) unique to C Reactor and was eventually responsible for that reactor being deactivated in 1985. A program of visual examinationsmore » of the SRS reactor tanks was initiated in 1968, which used a specially designed immersible periscope. Under that program the condition of the accessible tank welds and associated heat affected zones (HAZ) was evaluated on a five-year frequency. Prior to 1986, the scope of these inspections comprised approximately 20 percent of the accessible weld area. In late 1986 and early 1987 the scope of the inspections was expanded and a 100 percent visual inspection of accessible welds was performed of the P-, L-, and K-Reactor tanks. Supplemental dye penetrant examinations were performed in L Reactor on selected areas which showed visual indications. No evidence of cracking was detected in any of these inspections of the P-, L-, and K-Reactor tanks. 17 refs., 7 figs.« less

Inservice Program for Math/Science Teachers.

ERIC Educational Resources Information Center

Kinsley, Carol W.; Sweet, Helaine D.

1986-01-01

A school-business partnership between Monsanto Company and the Springfield Public Schools, Massachusetts, focuses on inservice teacher education. Seminar series equip teachers with current information on the technological revolution. (CJH)

An Analysis and Validation of Vocational Special Needs Inservice Issues.

ERIC Educational Resources Information Center

Brown, James M.; And Others

This report presents the results of a four-year effort to develop a valid and reliable inservice needs assessment instrument. (The instrument was designed to identify competencies that should be the focus of inservice training for vocational educators who teach or provide services to special needs learners.) Chapter I is an introduction. Chapter…

Ultrasonic Interferometers Revisited

ERIC Educational Resources Information Center

Greenslade, Thomas B., Jr.

2007-01-01

I have been tinkering with ultrasonic transducers once more. In earlier notes I reported on optics-like experiments performed with ultrasonics, described a number of ultrasonic interferometers, and showed how ultrasonic transducers can be used for Fourier analysis. This time I became interested in trying the technique of using two detectors in…

Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers.

PubMed

López, Yuri Álvarez; Lorenzo, José Ángel Martínez

2017-01-15

One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated.

Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers

PubMed Central

Álvarez López, Yuri; Martínez Lorenzo, José Ángel

2017-01-01

One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated. PMID:28098841

Graduate & Inservice. [SITE 2001 Section].

ERIC Educational Resources Information Center

Crawford, Caroline M., Ed.

This document contains the papers on graduate and inservice teacher education from the SITE (Society for Information Technology & Teacher Education) 2001 conference. Topics covered include: media literacy across the curriculum; contextual learning about information technology (IT); IT in teacher education; reform in a graduate school…

Development of Heat-Affected Zone Hardness Limits for In-Service Welding

DOT National Transportation Integrated Search

2009-09-29

Welding onto in-service pipelines is frequently required to facilitate a repair or to install a branch connection using the "hot tapping" technique. Welds made in-service cool at an accelerated rate as the result of the ability of the flowing content...

Nondestructive and Destructive Examination Studies on Removed-from-Service Control Rod Drive Mechanism Penetrations

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

Cumblidge, Stephen E.; Crawford, Susan L.; Doctor, Steven R.

2007-06-07

Studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, focused on assessing the effectiveness of nondestructive examination (NDE) techniques for inspecting control rod drive mechanism (CRDM) nozzles and J-groove weldments. The primary objectives of this work are to provide information to the U.S. Nuclear Regulatory Commission (NRC) on the effectiveness of NDE methods as related to the in-service inspection of CRDM nozzles and J-groove weldments and to enhance the knowledge base of primary water stress corrosion cracking (PWSCC) through destructive characterization of the CRDM assemblies. Two CRDM assemblies were removed from service, decontaminated, and then used inmore » a series of NDE and destructive examination (DE) measurements; this report addresses the following questions: 1) What did each NDE technique detect? 2) What did each NDE technique miss? 3) How accurately did each NDE technique characterize the detected flaws? 4) Why did the NDE techniques perform or not perform? Two CRDM assemblies including the CRDM nozzle, the J-groove weld, buttering, and a portion of the ferritic head material were selected for this study. This report focuses on a CRDM assembly that contained suspected PWSCC, based on in-service inspection data and through-wall leakage. The NDE measurements used to examine the CRDM assembly followed standard industry techniques for conducting in-service inspections of CRDM nozzles and the crown of the J-groove welds and buttering. These techniques included eddy current testing (ET), time-of-flight diffraction ultrasound, and penetrant testing. In addition, laboratory-based NDE methods were employed to conduct inspections of the CRDM assembly with particular emphasis on inspecting the J-groove weld and buttering. These techniques included volumetric ultrasonic inspection of the J-groove weld metal and visual testing via replicant material of the J-groove weld. The results from these NDE studies were

Subsurface damage detection in non-ferrous systems using 3D synchronous magnetic inspection

NASA Astrophysics Data System (ADS)

Gray, David; Berry, David

2018-04-01

Prime Photonics is developing a non-destructive inspection (NDI) technology, 3-D synchronous magnetic imaging system (3-D SMIS), that uses synchronous detection of magnetic signatures resulting from ultrasonic excitation to measure both surface and subsurface flaws in conductive structures. 3-D SMIS is showing promise in a wide range of NDI/NDE uses including characterizing surface-breaking cracks in ferrous and non-ferrous materials, locating and characterizing subsurface cracks within nonferrous conductive materials (Ti 6-4 and carbon fiber composites), and characterization of subsurface residual stresses. The technology offers a non-contact, high resolution inspection technique that does not require austere environments, and can accommodate non-planar specimen geometries.

Microwave NDE of impact damaged fiberglass and elastomer layered composites

NASA Astrophysics Data System (ADS)

Greenawald, E. C.; Levenberry, L. J.; Qaddoumi, N.; McHardy, A.; Zoughi, R.; Poranski, C. F.

2000-05-01

Layered composites have been proposed as advanced materials for future use in large naval sonar domes. Unlike today's steel/rubber composite domes, such materials promise engineered acoustic properties and less costly resin-transfer fabrication methods. The development and deployment of these large and complex composite structures will result in challenging NDE requirements for both manufacturing quality assurance and in-service needs. Among the anticipated in-service requirements is the detection and characterization of the impact damage associated with striking a submerged object at sea. A one-sided inspection method is desired, preferably applicable in the underwater environment. In this paper, we present preliminary microwave NDE results from impact test coupons of a proposed thick FRP/elastomer/FRP "sandwich" composite. The coupons were scanned using a near-field microwave probe that responds to the composite's dielectric properties. The unprocessed scan data was displayed in an image format to reveal damaged areas. Results are compared with those from x-ray backscatter imaging and ultrasonic testing, and are verified by destructive analysis of the coupons. The difficulties posed by the application are discussed, as are the operating principles and advantages of the microwave methods. The importance of optimizing inspection parameters such as frequency and standoff distance is emphasized for future work.

An Examination of Technology Training Experiences from Teacher Candidacy to In-Service Professional Development

ERIC Educational Resources Information Center

Williams, Mable Evans

2017-01-01

The purpose of this qualitative study was to explore the perceptions of in-service teachers concerning the effectiveness of technology training from a teacher education preparation program to in-service professional development. The findings of the study revealed that inservice teachers have had varying degrees of technology experiences from their…

Secondary Vocational Agriculture Inservice Training.

ERIC Educational Resources Information Center

Texas A and M Univ., College Station. Dept. of Agricultural Education.

This document briefly describes the objectives, procedures, accomplishments, and findings of a project to provide inservice training for secondary vocational agriculture teachers in Texas. It then details a survey of the 933 teachers attending the resulting State Professional Improvement Conference for Teachers of Agricultural Science. The survey…

Defect detection performance of the UCSD non-contact air-coupled ultrasonic guided wave inspection of rails prototype

NASA Astrophysics Data System (ADS)

Mariani, Stefano; Nguyen, Thompson V.; Sternini, Simone; Lanza di Scalea, Francesco; Fateh, Mahmood; Wilson, Robert

2016-04-01

The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is developing a system for high-speed and non-contact rail defect detection. A prototype using an ultrasonic air-coupled guided wave signal generation and air-coupled signal detection, paired with a real-time statistical analysis algorithm, has been realized. This system requires a specialized filtering approach based on electrical impedance matching due to the inherently poor signal-to-noise ratio of air-coupled ultrasonic measurements in rail steel. Various aspects of the prototype have been designed with the aid of numerical analyses. In particular, simulations of ultrasonic guided wave propagation in rails have been performed using a Local Interaction Simulation Approach (LISA) algorithm. The system's operating parameters were selected based on Receiver Operating Characteristic (ROC) curves, which provide a quantitative manner to evaluate different detection performances based on the trade-off between detection rate and false positive rate. The prototype based on this technology was tested in October 2014 at the Transportation Technology Center (TTC) in Pueblo, Colorado, and again in November 2015 after incorporating changes based on lessons learned. Results from the 2015 field test are discussed in this paper.

Teachers' Expectations from In-Service Training and the Project "No Limit to Teach(er)"

ERIC Educational Resources Information Center

Akçadag, Tuncay

2012-01-01

Problem Statement: Training qualified teachers is possible through pre-service and in-service training programs. The in-service training of teachers in Turkey is primarily planned and delivered by the Directorate of In-Service Office at the Ministry of National Education (MoNE). In addition to this, some Non Governmental Organizations (NGO)…

The Opinions of Administrators about In-Service Training Related to the Administration and Investigation

ERIC Educational Resources Information Center

Demirel, Ihsan Nuri

2018-01-01

The purpose of this study is to determine the opinions of administrators of National Education Directiorate, School Directors and Vice-school Directors about the in-service activities and the system of in-service training programs related to work security. Moreover, it is investigated the level of the knowledge whether in-service training ignores…

Insights Gained from Ultrasonic Testing of Piping Welds Subjected to the Mechanical Stress Improvement Process

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

Anderson, Michael T.; Cinson, Anthony D.; Crawford, Susan L.

2010-12-01

Pacific Northwest National Laboratory (PNNL) is assisting the United States Nuclear Regulatory Commission (NRC) in developing a position on the management of primary water stress corrosion cracking (PWSCC) in leak-before-break piping systems. Part of this involves determining whether inspections alone, or inspections plus mitigation, are needed. This work addresses the reliability of ultrasonic testing (UT) of cracks that have been mitigated by the mechanical stress improvement process (MSIP). The MSIP has been approved by the NRC (NUREG-0313) since 1986 and modifies residual stresses remaining after welding with compressive, or neutral, stresses near the inner diameter surface of the pipe. Thismore » compressive stress is thought to arrest existing cracks and inhibit new crack formation. To evaluate the effectiveness of the MSIP and the reliability of ultrasonic inspections, flaws were evaluated both before and after MSIP application. An initial investigation was based on data acquired from cracked areas in 325-mm-diameter piping at the Ignalina Nuclear Power Plant (INPP) in Lithuania. In a follow-on exercise, PNNL acquired and evaluated similar UT data from a dissimilar metal weld (DMW) specimen containing implanted thermal fatigue cracks. The DMW specimen is a carbon steel nozzle-to-safe end-to-stainless steel pipe section that simulates a pressurizer surge nozzle. The flaws were implanted in the nozzle-to-safe end Alloy 82/182 butter region. Results are presented on the effects of MSIP on specimen surfaces, and on UT flaw responses.« less

Inservice Packet Undertaken for the Vocational Assessment for Special Needs Project.

ERIC Educational Resources Information Center

Hemphill, Norma Jean

The inservice package for assessment team members is designed to provide skill training regarding the vocational assessment process used with special needs students. Activities within the inservice training package sensitize individuals to the purposes of infusing vocational assessment into the educational curriculum, and provide instruction on…

Evaluation of Die-Attach Bonding Using High-Frequency Ultrasonic Energy for High-Temperature Application

NASA Astrophysics Data System (ADS)

Lee, Jong-Bum; Aw, Jie-Li; Rhee, Min-Woo

2014-09-01

Room-temperature die-attach bonding using ultrasonic energy was evaluated on Cu/In and Cu/Sn-3Ag metal stacks. The In and Sn-3Ag layers have much lower melting temperatures than the base material (Cu) and can be melted through the heat generated during ultrasonic bonding, forming intermetallic compounds (IMCs). Samples were bonded using different ultrasonic powers, bonding times, and forces and subsequently aged at 300°C for 500 h. After aging, die shear testing was performed and the fracture surfaces were inspected by scanning electron microscopy. Results showed that the shear strength of Cu/In joints reached an upper plateau after 100 h of thermal aging and remained stable with aging time, whereas that of the Cu/Sn-3Ag joints decreased with increasing aging time. η-Cu7In4 and (Cu,Au)11In9 IMCs were observed at the Cu/In joint, while Cu3Sn and (Ag,Cu)3Sn IMCs were found at the Cu/Sn-3Ag joint after reliability testing. As Cu-based IMCs have high melting temperatures, they are highly suitable for use in high-temperature electronics, but can be formed at room temperature using an ultrasonic approach.

Nondestructive inspection of bonded composite doublers for aircraft

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

Roach, D.; Moore, D.; Walkington, P.

1996-12-31

One major thrust in FAA`s National Aging Aircraft Research Program is to foster new technologies in civil aircraft maintenance. Recent DOD and other government developments in using bonded composite doublers on metal structures support the need for validation of such doubler applications on US certificated airplanes. In this study, a specific composite application was chosen on an L-1011 aircraft. Primary inspection requirements for these doublers include identifying disbonds between composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the double is also a concern. No singlemore » NDI method can inspect for every flaw type, therefore we need to know NDI capabilities and limitations. This paper reports on a series of NDI tests conducted on laboratory test structures and on a fuselage section from a retired L-1011. Application of ultrasonics, x-ray, and eddy current to composite doublers and results from test specimens loaded to provide a changing flaw profile, are presented in this paper. Development of appropriate inspection calibration standards are also discussed.« less

Attitudes of Preservice and Inservice Teachers toward Working with School Librarians.

ERIC Educational Resources Information Center

Getz, Irith

1996-01-01

Examines how preservice and inservice teachers relate to working cooperatively with school librarians in the instructional process, and how attitude components form and change. A study found no difference between the attitudes of preservice and inservice teachers. School size and teachers' knowledge about librarians and library education were…

In-Service Education of Teachers: Overview, Problems and the Way Forward

ERIC Educational Resources Information Center

Osamwonyi, Eduwen Friday

2016-01-01

The need for in-service education of teachers cannot be underestimated. It is a necessity in enhancing work performance and motivation of teachers in the field. Absence of in-service training of teachers will retard professional growth of teachers as well as "missing gaps" between demands and actual achievement levels. Inservice…

An optical fiber guided ultrasonic excitation and sensing system for online monitoring of nuclear power plants

NASA Astrophysics Data System (ADS)

Yang, J.; Lee, H.; Sohn, H.

2012-05-01

This study presents an embedded laser ultrasonic system for pipeline monitoring under high temperature environment. Recently, laser ultrasonics is becoming popular because of their advantageous characteristics such as (a) noncontact inspection, (b) immunity against electromagnetic interference (EMI), and (c) applicability under high temperature. However, the performance of conventional laser ultrasonic techniques for pipeline monitoring has been limited because many pipelines are covered by insulating materials and target surfaces are inaccessible. To overcome the problem, this study designs an embeddable optical fibers and fixing devices that deliver laser beams from laser sources to a target pipe using embedded optical fibers. For guided wave generation, an optical fiber is furnished with a beam collimator for irradiating a laser beam onto a target structure. The corresponding response is measured based on the principle of laser interferometry. Light from a monochromatic source is colliminated and delivered to a target surface by another optical with a focusing module, and reflected light is transmitted back to the interferometer through the same fiber. The feasibility of the proposed system for embedded ultrasonic measurement has been experimentally verified using a pipe specimen under high temperature.

A fractional Fourier transform analysis of the scattering of ultrasonic waves.

PubMed

Tant, Katherine M M; Mulholland, Anthony J; Langer, Matthias; Gachagan, Anthony

2015-03-08

Many safety critical structures, such as those found in nuclear plants, oil pipelines and in the aerospace industry, rely on key components that are constructed from heterogeneous materials. Ultrasonic non-destructive testing (NDT) uses high-frequency mechanical waves to inspect these parts, ensuring they operate reliably without compromising their integrity. It is possible to employ mathematical models to develop a deeper understanding of the acquired ultrasonic data and enhance defect imaging algorithms. In this paper, a model for the scattering of ultrasonic waves by a crack is derived in the time-frequency domain. The fractional Fourier transform (FrFT) is applied to an inhomogeneous wave equation where the forcing function is prescribed as a linear chirp, modulated by a Gaussian envelope. The homogeneous solution is found via the Born approximation which encapsulates information regarding the flaw geometry. The inhomogeneous solution is obtained via the inverse Fourier transform of a Gaussian-windowed linear chirp excitation. It is observed that, although the scattering profile of the flaw does not change, it is amplified. Thus, the theory demonstrates the enhanced signal-to-noise ratio permitted by the use of coded excitation, as well as establishing a time-frequency domain framework to assist in flaw identification and classification.

A fractional Fourier transform analysis of the scattering of ultrasonic waves

PubMed Central

Tant, Katherine M.M.; Mulholland, Anthony J.; Langer, Matthias; Gachagan, Anthony

2015-01-01

Many safety critical structures, such as those found in nuclear plants, oil pipelines and in the aerospace industry, rely on key components that are constructed from heterogeneous materials. Ultrasonic non-destructive testing (NDT) uses high-frequency mechanical waves to inspect these parts, ensuring they operate reliably without compromising their integrity. It is possible to employ mathematical models to develop a deeper understanding of the acquired ultrasonic data and enhance defect imaging algorithms. In this paper, a model for the scattering of ultrasonic waves by a crack is derived in the time–frequency domain. The fractional Fourier transform (FrFT) is applied to an inhomogeneous wave equation where the forcing function is prescribed as a linear chirp, modulated by a Gaussian envelope. The homogeneous solution is found via the Born approximation which encapsulates information regarding the flaw geometry. The inhomogeneous solution is obtained via the inverse Fourier transform of a Gaussian-windowed linear chirp excitation. It is observed that, although the scattering profile of the flaw does not change, it is amplified. Thus, the theory demonstrates the enhanced signal-to-noise ratio permitted by the use of coded excitation, as well as establishing a time–frequency domain framework to assist in flaw identification and classification. PMID:25792967

Double-Shell Tank Visual Inspection Changes Resulting from the Tank 241-AY-102 Primary Tank Leak

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

Girardot, Crystal L.; Washenfelder, Dennis J.; Johnson, Jeremy M.

2013-11-14

As part of the Double-Shell Tank (DST) Integrity Program, remote visual inspections are utilized to perform qualitative in-service inspections of the DSTs in order to provide a general overview of the condition of the tanks. During routine visual inspections of tank 241-AY-102 (AY-102) in August 2012, anomalies were identified on the annulus floor which resulted in further evaluations. In October 2012, Washington River Protection Solutions, LLC determined that the primary tank of AY-102 was leaking. Following identification of the tank AY-102 probable leak cause, evaluations considered the adequacy of the existing annulus inspection frequency with respect to the circumstances ofmore » the tank AY-102 1eak and the advancing age of the DST structures. The evaluations concluded that the interval between annulus inspections should be shortened for all DSTs, and each annulus inspection should cover > 95 percent of annulus floor area, and the portion of the primary tank (i.e., dome, sidewall, lower knuckle, and insulating refractory) that is visible from the annulus inspection risers. In March 2013, enhanced visual inspections were performed for the six oldest tanks: 241-AY-101, 241-AZ-101,241-AZ-102, 241-SY-101, 241-SY-102, and 241-SY-103, and no evidence of leakage from the primary tank were observed. Prior to October 2012, the approach for conducting visual examinations of DSTs was to perform a video examination of each tank's interior and annulus regions approximately every five years (not to exceed seven years between inspections). Also, the annulus inspection only covered about 42 percent of the annulus floor.« less

Efficacy of Teacher In-Service Training for Attention-Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Jones, Heather A.; Chronis-Tuscano, Andrea

2008-01-01

Children with attention-deficit/hyperactivity disorder (ADHD) evidence many problems in the classroom. Teacher in-service training is routinely used to inform school professionals about a number of special topics; however, the efficacy of such in-service training for ADHD has not been established. The present study examined the efficacy of brief…

Beijing In-Service Teachers' Self-Efficacy and Attitudes towards Inclusive Education

ERIC Educational Resources Information Center

Malinen, Olli-Pekka; Savolainen, Hannu; Xu, Jiacheng

2012-01-01

Four-hundred-and-fifty-one in-service teachers from the Beijing municipality filled in a questionnaire containing a Teacher Efficacy for Inclusive Practices (TEIP) scale. The aim was to examine the factor structure of the TEIP scale among mainland Chinese in-service teachers, and to investigate the relationship between self-efficacy for inclusive…

Numerical investigations of internal stresses on carbon steel based on ultrasonic LCR waves

NASA Astrophysics Data System (ADS)

Ramasamy, R.; Ibrahim, Z.; Chai, H. K.

2017-10-01

Internal stresses or residual stresses in the structural elements are very crucial in carrying out in-service evaluations and fitness-for-purpose assessments. The generation of these internal stresses can occur as result of the fabrication of the steel members, installation sequence or other ad-hoc events such as accidents or impact. The accurate prediction of the internal stresses will contribute towards estimating the integrity state of the structural elements, with respect to their material allowable stresses. This paper investigates the explicit FE based numerical modelling of the ultrasonic based non-destructive technique, utilising the measurable longitudinal critical refracted wave (LCR) and relating these to the internal stresses within the structural elements by the evaluation of the material dependent acoustoelastic factors. The subsurface travel path of the LCR wave inside the structural elements makes it a sub-surface stress measurement technique and the linearised relationship with corresponding internal stresses can be systematically applied repeatedly. The numerical results are compared against laboratory tests data to correlate the findings and to establish modelling feasibility for future proof-of-concepts. It can be concluded from this numerical investigation, that the subsurface ultrasonic LCR wave has great potential to be implemented for in-situ structural residual stress measurements, as compared to other available surface measurements such as strain gauges or x-ray diffraction.

Ultrasonic Motors

DTIC Science & Technology

2003-06-01

micromotor have been investigated. The piezoelectric motor makes use of two orthogonal bending modes of a hollow cylinder. The vibrating element...A.Iino, K.Suzuki, M.Kasuga, M.Suzuki and T.Yamanaka, "Development of a Self- Oscillating Ultrasonic Micromotor and Its Application to a Watch...pp. 823-828, 1997. [12] M. K. Kurosawa, T. Morita, and T. Higuchi, "A Cylindrical Ultrasonic Micromotor Based on PZT Thin Film," IEEE Ultrasonics

Split-spectrum processing technique for SNR enhancement of ultrasonic guided wave.

PubMed

Pedram, Seyed Kamran; Fateri, Sina; Gan, Lu; Haig, Alex; Thornicroft, Keith

2018-02-01

Ultrasonic guided wave (UGW) systems are broadly used in several branches of industry where the structural integrity is of concern. In those systems, signal interpretation can often be challenging due to the multi-modal and dispersive propagation of UGWs. This results in degradation of the signals in terms of signal-to-noise ratio (SNR) and spatial resolution. This paper employs the split-spectrum processing (SSP) technique in order to enhance the SNR and spatial resolution of UGW signals using the optimized filter bank parameters in real time scenario for pipe inspection. SSP technique has already been developed for other applications such as conventional ultrasonic testing for SNR enhancement. In this work, an investigation is provided to clarify the sensitivity of SSP performance to the filter bank parameter values for UGWs such as processing bandwidth, filter bandwidth, filter separation and a number of filters. As a result, the optimum values are estimated to significantly improve the SNR and spatial resolution of UGWs. The proposed method is synthetically and experimentally compared with conventional approaches employing different SSP recombination algorithms. The Polarity Thresholding (PT) and PT with Minimization (PTM) algorithms were found to be the best recombination algorithms. They substantially improved the SNR up to 36.9dB and 38.9dB respectively. The outcome of the work presented in this paper paves the way to enhance the reliability of UGW inspections. Copyright © 2017 Elsevier B.V. All rights reserved.

Inspection and repair of steam generator tubing with a robot

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

Boehm, H.H.; Foerch, H.

1985-11-01

During inspection and repair of steam generator tubing, radiation exposure to personnel is an unrequested endowment. To combat this intrinsic handicap, a robot has been designed for deployment in all operations inside the steam generator water chamber. This measure drastically reduces entering time and also improves inspection capabilities with regard to the accuracy and reproduction of the desired tube address. The inherent flexibility of the robot allows for performing various inspection and repair techniques: eddy-current testing of tubing; ultrasonic testing of tubing; visual examination of tube ends; profilometry measurements; tube plugging; plug removal; tube extraction; sleeving of tubes; tube endmore » repair; chemical cleaning; and thermal treatment. Plant experience has highlighted the following features of the robot: 1) short installation and demounting periods; 2) installation independent of manhole location; 3) installation possible from outside the steam generator; 4) only one relocation required to address all the tube positions; 5) fast and highly accurate positioning; 6) operational surveillance not required; and 7) drastic reduction of radiation exposure to personnel during repair work.« less

Line Scanning Thermography for Rapid Nondestructive Inspection of Large Scale Composites

NASA Astrophysics Data System (ADS)

Chung, S.; Ley, O.; Godinez, V.; Bandos, B.

2011-06-01

As next generation structures are utilizing larger amounts of composite materials, a rigorous and reliable method is needed to inspect these structures in order to prevent catastrophic failure and extend service life. Current inspection methods, such as ultrasonic, generally require extended down time and man hours as they are typically carried out via point-by-point measurements. A novel Line Scanning Thermography (LST) System has been developed for the non-contact, large-scale field inspection of composite structures with faster scanning times than conventional thermography systems. LST is a patented dynamic thermography technique where the heat source and thermal camera move in tandem, which allows the continuous scan of long surfaces without the loss of resolution. The current system can inspect an area of 10 in2 per 1 second, and has a resolution of 0.05×0.03 in2. Advanced data gathering protocols have been implemented for near-real time damage visualization and post-analysis algorithms for damage interpretation. The system has been used to successfully detect defects (delamination, dry areas) in fiber-reinforced composite sandwich panels for Navy applications, as well as impact damage in composite missile cases and armor ceramic panels.

Ultrasonic Array for Obstacle Detection Based on CDMA with Kasami Codes

PubMed Central

Diego, Cristina; Hernández, Álvaro; Jiménez, Ana; Álvarez, Fernando J.; Sanz, Rebeca; Aparicio, Joaquín

2011-01-01

This paper raises the design of an ultrasonic array for obstacle detection based on Phased Array (PA) techniques, which steers the acoustic beam through the environment by electronics rather than mechanical means. The transmission of every element in the array has been encoded, according to Code Division for Multiple Access (CDMA), which allows multiple beams to be transmitted simultaneously. All these features together enable a parallel scanning system which does not only improve the image rate but also achieves longer inspection distances in comparison with conventional PA techniques. PMID:22247675

Single-Transducer, Ultrasonic Imaging Method for High-Temperature Structural Materials Eliminates the Effect of Thickness Variation in the Image

NASA Technical Reports Server (NTRS)

Roth, Don J.

1998-01-01

NASA Lewis Research Center's Life Prediction Branch, in partnership with Sonix, Inc., and Cleveland State University, recently advanced the development of, refined, and commercialized an advanced nondestructive evaluation (NDE) inspection method entitled the Single Transducer Thickness-Independent Ultrasonic Imaging Method. Selected by R&D Magazine as one of the 100 most technologically significant new products of 1996, the method uses a single transducer to eliminate the superimposing effects of thickness variation in the ultrasonic images of materials. As a result, any variation seen in the image is due solely to microstructural variation. This nondestructive method precisely and accurately characterizes material gradients (pore fraction, density, or chemical) that affect the uniformity of a material's physical performance (mechanical, thermal, or electrical). Advantages of the method over conventional ultrasonic imaging include (1) elimination of machining costs (for precision thickness control) during the quality control stages of material processing and development and (2) elimination of labor costs and subjectivity involved in further image processing and image interpretation. At NASA Lewis, the method has been used primarily for accurate inspections of high temperature structural materials including monolithic ceramics, metal matrix composites, and polymer matrix composites. Data were published this year for platelike samples, and current research is focusing on applying the method to tubular components. The initial publicity regarding the development of the method generated 150 requests for further information from a wide variety of institutions and individuals including the Federal Bureau of Investigation (FBI), Lockheed Martin Corporation, Rockwell International, Hewlett Packard Company, and Procter & Gamble Company. In addition, NASA has been solicited by the 3M Company and Allison Abrasives to use this method to inspect composite materials that are

Administrative Inservice and Theories of Groups.

ERIC Educational Resources Information Center

Wimpelberg, Robert K.

Voluntary organizations providing inservice activities for principals are the newest in the administrative development field. This paper explores those organizations' prospects, particularly the voluntary, administrator-directed "principals' center," and borrows its analytical framework from theories of group formation. The Principals' Center in…

In-Service Training and Development Programs for Accountants in Business and Industry.

ERIC Educational Resources Information Center

Adams, Hobart Warren

A survey was made of inservice training and development for accountants in 53 selected business firms varying in products, sales volume, and employees. Program philosophy and objectives, qualifications and selection of trainees and instructors, program content, instructional programs, and evaluation procedures were examined. Inservice programs,…

In-Service Training Programmes for Inclusive Education in Serbia--Offer and Implementation

ERIC Educational Resources Information Center

Matovic, Nataša; Spasenovic, Vera

2015-01-01

The initial education and in-service training of all educators, particularly teachers, play a vital role in strengthening competences necessary for implementing inclusive educational practice. This paper analyses offered and implemented inservice training programmes for educators in the field of inclusive education or, more precisely, for working…

Planning and In-Service Education.

ERIC Educational Resources Information Center

Alvir, Howard P.

This booklet is designed to render assistance to all educators engaged in planning in-service education sessions with their staff. Specifically, it offers a point of view on planning as a learnable activity and a reasonably complete how-to-do-it kit. The objectives of such an approach are to pinpoint specific planning difficulties associated with…

Quantitative diagnostics of multilayered composite structures with ultrasonic guided waves

NASA Astrophysics Data System (ADS)

Bunget, Gheorghe; Friedersdorf, Fritz; Na, Jeong K.

2015-03-01

The main objective of the current work is to develop a practical nondestructive inspection methodology for a highly sound absorbing composite structural system consisting of polymeric and metallic materials. Due to constraints in geometrical shapes and thicknesses of the composite system used in this work, ultrasonic guided wave approach has been chosen. Since the polymer coatings have high damping properties, less energy is dissipated into the adjacent media in the presence of interface delaminations. Experimental measurements performed on a targeted composite system, whether it has an aluminum, carbon-fiber-composite, or steel outer casing, show promising results.

Advanced Ultrasonic Measurement Methodology for Non-Invasive Interrogation and Identification of Fluids in Sealed Containers

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

Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

2006-03-16

The Hazardous Materials Response Unit (HMRU) and the Counterterrorism and Forensic Science Research Unit (CTFSRU), Laboratory Division, Federal Bureau of Investigation (FBI) have been mandated to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a portable, hand-held, hazardous materials acoustic inspection device (HAZAID) that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as wellmore » as container sizes and materials, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The HAZAID prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the HAZAID prototype. High bandwidth ultrasonic transducers combined with the advanced pulse compression technique allowed researchers to 1) impart large amounts of energy, 2) obtain high signal-to-noise ratios, and 3) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of this feasibility study demonstrated that the HAZAID experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.« less

In-Service Teacher Training in Japan and Turkey: A Comparative Analysis of Institutions and Practices

ERIC Educational Resources Information Center

Bayrakci, Mustafa

2009-01-01

The purpose of this study is to compare policies and practices relating to teacher in-service training in Japan and Turkey. On the basis of the findings of the study, suggestions are made about in-service training activities in Turkey. The research was carried using qualitative research methods. In-service training activities in the two education…

Piping inspection instrument carriage with precise and repeatable position control and location determination

DOEpatents

Hapstack, Mark; Talarek, Ted R.; Zollinger, W. Thor; Heckendorn, II, Frank M.; Park, Larry R.

1994-01-01

An instrument carriage for inspection of piping comprises front and rear leg assemblies for engaging the interior of the piping and supporting and centering the carriage therein, and an instrumentation arm carried by a shaft system running from the front to rear leg assemblies. The shaft system has a screw shaft for moving the arm axially and a spline gear for moving the arm azimuthally. The arm has a pair of air cylinders that raise and lower a plate in the radial direction. On the plate are probes including an eddy current probe and an ultrasonic testing probe. The ultrasonic testing probe is capable of spinning 360.degree. about its axis. The instrument carriage uses servo motors and pressurized air cylinders for precise actuation of instrument components and precise, repeatable actuation of position control mechanisms.

Inservice Teachers' Perceptions of Educational Assessment.

ERIC Educational Resources Information Center

Quilter, Shawn M.; Chester, Cher

This study examined inservice teachers' perceptions of classroom assessment, standardized testing, and alternative assessment methods. Participants were 168 predominantly white, predominantly female teachers working on master's degrees at Eastern Michigan University and the Citadel. During the fall of 1997, they completed a questionnaire that…

Four Issues in Teacher Inservice Education.

ERIC Educational Resources Information Center

Butler, Loretta

The problems facing implementation of a sound inservice program are examined from diverse viewpoints. Selective samples from policy papers by relevant educational institutions and organizations are analyzed. These papers present some consensus and some conflicting perceptions on the issues of shared governance, program content, resource…

Surveying Chinese In-Service K12 Teachers' Technology, Pedagogy, and Content Knowledge

ERIC Educational Resources Information Center

Liu, Qingtang; Zhang, Si; Wang, Qiyun

2015-01-01

Technology, pedagogy, and content knowledge (TPACK) has been considered as a promising theoretical framework to guide teacher educators in designing and developing in-service K12 teacher education programs. However, it seems unclear whether in-service teachers have different TPACK perceptions when entering the education programs. This study…

Increasing the Effectiveness of Inservice Training for Desegregation: A Synthesis of Current Research. Reference & Resource Series.

ERIC Educational Resources Information Center

Smylie, Mark A.; Hawley, Willis D.

This report reviews recent research on strategies that have been found to promote useful and effective inservice training programs in desegregated schools. The first section presents approaches for planning and implementing inservice training for desegregation. The second section describes inservice desegregation training programs that focus on:…

Inservice Elementary and Middle School Teachers' Conceptions of Photosynthesis and Respiration

NASA Astrophysics Data System (ADS)

Krall, Rebecca Mcnall; Lott, Kimberly H.; Wymer, Carol L.

2009-02-01

The purpose of this descriptive study was to investigate inservice elementary and middle school teachers’ conceptions of photosynthesis and respiration, basic concepts they are expected to teach. A forced-choice instrument assessing selected standards-based life science concepts with non-scientific conceptions embedded in distracter options was utilized to assess 76 inservice elementary and middle school teachers from the central Appalachian region. Outcomes from four tasks assessing photosynthesis and respiration concepts are discussed. Findings revealed similarities between non-scientific conceptions the teachers demonstrated and non-scientific conceptions reported in the research literature on elementary and middle school students’ understanding of the concepts. Findings also informed subsequent inservice teacher professional development efforts in life science and the development of a biology course for preservice elementary teachers.

Improved NDI techniques for aircraft inspections

NASA Astrophysics Data System (ADS)

Hagemaier, Donald J.; Wilson, Dwight

1996-11-01

Through the use of an 'integrated product team' approach and new inspection techniques incorporating the latest in imaging capabilities and automation, the costs of some man- power intensive tasks can now be drastically reduced. Also, through the use of advanced eddy current techniques, the detectable size of cracks under flush-head fasteners can be reduced while maintaining a reliable inspection. Early in this decade, the FAA Technical Center and NASA LaRC formulated an aging aircraft research plan. The unique aspect about the research is that it is driven by the aircraft manufacturers and airlines in order to center only on those areas in which help is needed and to keep it focused. Once developed, the manufacturer works with the FAA Validation Center at Sandia National Labs., the airline, and the researcher to transfer technology to the field. This article describes the evaluation and results obtained using eddy current technology to determine the minimum detectable crack size under installed flush-head fasteners. Secondly, it describes the integrated efforts of engineers at McDonnell Douglas Aerospace and Northwest Airlines in the successful application of MAUS eddy current C-scanning of the DC-10 circumferential and axial crown splices. The eddy current C-scanning greatly reduced the man-hour effort required for the existing radiographic inspection. Thirdly, it describes the use of a novel ultrasonic technique coupled to a scanner and graphics for the detection and quantification of corrosion thinning and stress corrosion cracking of the DC-9 lower wing tee cap. This successful effort resulted from a rather large integrated task team. It also results in a vast man-hour savings over the existing internal visual inspection.

Inservice Science Courses for Primary Teachers: Implementation of Different Types of Inservice Training Courses in Finland.

ERIC Educational Resources Information Center

Asunta, Tuula

1997-01-01

Reports on the effects of six different primary inservice training courses aimed at teachers' motivation, anxieties, hands-on working skills, and support needs. Results showed that primary teachers felt they needed more continuous support in the area of improving their knowledge and understanding of the subject, especially in chemistry and…

Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

NASA Technical Reports Server (NTRS)

Miller, James G.

1997-01-01

In this Progress Report, we describe our recent developments of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns for a thin woven composite in an immersion setup. In addition, we compare apparent signal loss measurements of the thin woven composite for phase-sensitive and phase-insensitive detection methods. All images of diffraction patterns have been included on the accompanying CD-ROM in the Adobe(Trademark) Portable Document Format (PDF). Due to the extensive amount of data, however, hardcopies of only a small representative selection of the images are included within the printed report. This Progress Report presents experimental results that support successful implementation of single element as well as one and two-dimensional ultrasonic array technologies for the inspection of textile composite structures. In our previous reports, we have addressed issues regarding beam profiles of ultrasonic pressure fields transmitted through a water reference path and transmitted through a thin woven composite sample path. Furthermore, we presented experimental results of the effect of a thin woven composite on the magnitude of an insonifying ultrasonic pressure field. In addition to the study of ultrasonic beam profiles, we consider issues relevant to the application of single-element, one-dimensional, and two-dimensional array technologies towards probing the mechanical properties of advanced engineering composites and structures. We provide comparisons between phase-sensitive and phase-insensitive detection methods for determination of textile composite structure parameters. We also compare phase-sensitive and phase-insensitive - - ---- ----- apparent signal loss measurements in an effort to study the phenomenon of phase cancellation at the face of a finite-aperture single-element receiver. Furthermore, in this

Ultrasonic Maintenance

NASA Technical Reports Server (NTRS)

1991-01-01

The Ultraprobe 2000, manufactured by UE Systems, Inc., Elmsford, NY, is a hand-held ultrasonic system that detects indications of bearing failure by analyzing changes in amplitude. It employs the technology of a prototype ultrasonic bearing-failure monitoring system developed by Mechanical Technology, Inc., Latham, New York and Marshall Space Flight Center (which was based on research into Skylab's gyroscope bearings). Bearings on the verge of failure send ultrasonic signals indicating their deterioration; the Ultraprobe changes these to audible signals. The operator hears the signals and gages their intensity with a meter in the unit.

Accuracy testing of steel and electric groundwater-level measuring tapes: Test method and in-service tape accuracy

USGS Publications Warehouse

Fulford, Janice M.; Clayton, Christopher S.

2015-10-09

The calibration device and proposed method were used to calibrate a sample of in-service USGS steel and electric groundwater tapes. The sample of in-service groundwater steel tapes were in relatively good condition. All steel tapes, except one, were accurate to ±0.01 ft per 100 ft over their entire length. One steel tape, which had obvious damage in the first hundred feet, was marginally outside the accuracy of ±0.01 ft per 100 ft by 0.001 ft. The sample of in-service groundwater-level electric tapes were in a range of conditions—from like new, with cosmetic damage, to nonfunctional. The in-service electric tapes did not meet the USGS accuracy recommendation of ±0.01 ft. In-service electric tapes, except for the nonfunctional tape, were accurate to about ±0.03 ft per 100 ft. A comparison of new with in-service electric tapes found that steel-core electric tapes maintained their length and accuracy better than electric tapes without a steel core. The in-service steel tapes could be used as is and achieve USGS accuracy recommendations for groundwater-level measurements. The in-service electric tapes require tape corrections to achieve USGS accuracy recommendations for groundwater-level measurement.

Ultrasonic Nondestructive Evaluation of PRSEUS Pressure Cube Article in Support of Load Test to Failure

NASA Technical Reports Server (NTRS)

Johnston, Patrick H.

2013-01-01

The PRSEUS Pressure Cube Test was a joint development effort between the Boeing Company and NASA Langley Research Center, sponsored in part by the Environmentally Responsible Aviation Project and Boeing internal R&D. This Technical Memorandum presents the results of ultrasonic inspections in support of the PRSEUS Pressure Cube Test, and is a companion document with the NASA test report and a report on the acoustic emission measurements made during the test.

Effect of Ultrasonic Frequency on Lactic Acid Fermentation Promotion by Ultrasonic Irradiation

NASA Astrophysics Data System (ADS)

Shimada, Tadayuki; Ohdaira, Etsuzo; Masuzawa, Nobuyoshi

2004-05-01

The authors have been researching the promotion of lactic acid fermentation by ultrasonic irradiation. In the past research, it was proven that ultrasonic irradiation is effective in the process of fermentation, and the production of yoghurt and kefir was promoted. In this study, the effect of the ultrasonic frequency in this fermentation process was examined. In the frequency range of this study, it was found that the action of fermentation promotion was exponentially proportionate to the irradiated ultrasonic frequency.

Millimeter Wave Holographical Inspection of Honeycomb Composites

NASA Technical Reports Server (NTRS)

Case, J. T.; Kharkovsky, S.; Zoughi, R.; Stefes, G.; Hepburn, Frank L.; Hepburn, Frank L.

2007-01-01

Multi-layered composite structures manufactured with honeycomb, foam or balsa wood cores are finding increasing utility in a variety of aerospace, transportation, and infrastructure applications. Due to the low conductivity and inhomogeneity associated with these composites standard nondestructive testing (NDT) methods are not always capable of inspecting their interior for various defects caused during the manufacturing process or as a result of in-service loading. On the contrary, microwave and millimeter wave NDT methods are well-suited for inspecting these structures since signals at these frequencies readily penetrate through these structures and reflect from different interior boundaries revealing the presence of a wide range of defects such as disbond, delamination, moisture and oil intrusion, impact damage, etc. Millimeter wave frequency spectrum spans 30 GHz - 300 GHz with corresponding wavelengths of 10 - 1 mm. Due to the inherent short wavelengths at these frequencies, one can produce high spatial resolution images of these composites either using real-antenna focused or synthetic-aperture focused methods. In addition, incorporation of swept-frequency in the latter method (i.e., holography) results in high-resolution three-dimensional images. This paper presents the basic steps behind producing such images at millimeter wave frequencies and the results of two honeycomb composite panels are demonstrated at Q-band (33-50 GHz). In addition, these results are compared to previous results using X-ray computed tomography.

Millimeter Wave Holographical Inspection of Honeycomb Composites

NASA Astrophysics Data System (ADS)

Case, J. T.; Kharkovsky, S.; Zoughi, R.; Steffes, G.; Hepburn, F. L.

2008-02-01

Multi-layered composite structures manufactured with honeycomb, foam, or balsa wood cores are finding increasing utility in a variety of aerospace, transportation, and infrastructure applications. Due to the low conductivity and inhomogeneity associated with these composites, standard nondestructive testing (NDT) methods are not always capable of inspecting their interior for various defects caused during the manufacturing process or as a result of in-service loading. On the contrary, microwave and millimeter wave NDT methods are well-suited for inspecting these structures since signals at these frequencies readily penetrate through these structures and reflect from different interior boundaries revealing the presence of a wide range of defects such as isband, delamination, moisture and oil intrusion, impact damage, etc. Millimeter wave frequency spectrum spans 30 GHz-300 GHz with corresponding wavelengths of 10-1 mm. Due to the inherent short wavelengths at these frequencies, one can produce high spatial resolution images of these composites either using real-antenna focused or synthetic-aperture focused methods. In addition, incorporation of swept-frequency in the latter method (i.e., holography) results in high-resolution three-dimensional images. This paper presents the basic steps behind producing such images at millimeter wave frequencies and the results of two honeycomb composite panels are demonstrated at Q-band (33-50 GHz). In addition, these results are compared to previous results using X-ray computed tomography.

Ultrasonic Phased Array Assessment of the Interference Fit and Leak Path of the North Anna Unit 2 Control Rod Drive Mechanism Nozzle 63 with Destructive Validation

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

Crawford, Susan L.; Cinson, Anthony D.; MacFarlan, Paul J.

2012-08-01

The objective of this investigation was to evaluate the efficacy of ultrasonic testing (UT) for primary water leak path assessments of reactor pressure vessel (RPV) upper head penetrations. Operating reactors have experienced leakage when stress corrosion cracking of nickel-based alloy penetrations allowed primary water into the annulus of the interference fit between the penetration and the low-alloy steel RPV head. In this investigation, UT leak path data were acquired for an Alloy 600 control rod drive mechanism nozzle penetration, referred to as Nozzle 63, which was removed from the North Anna Unit 2 reactor when the RPV head was replacedmore » in 2002. In-service inspection prior to the head replacement indicated that Nozzle 63 had a probable leakage path through the interference fit region. Nozzle 63 was examined using a phased-array UT probe with a 5.0-MHz, eight-element annular array. Immersion data were acquired from the nozzle inner diameter surface. The UT data were interpreted by comparing to responses measured on a mockup penetration with known features. Following acquisition of the UT data, Nozzle 63 was destructively examined to determine if the features identified in the UT examination, including leakage paths and crystalline boric acid deposits, could be visually confirmed. Additional measurements of boric acid deposit thickness and low-alloy steel wastage were made to assess how these factors affect the UT response. The implications of these findings for interpreting UT leak path data are described.« less

Probabilistic Fatigue Life Updating for Railway Bridges Based on Local Inspection and Repair.

PubMed

Lee, Young-Joo; Kim, Robin E; Suh, Wonho; Park, Kiwon

2017-04-24

Railway bridges are exposed to repeated train loads, which may cause fatigue failure. As critical links in a transportation network, railway bridges are expected to survive for a target period of time, but sometimes they fail earlier than expected. To guarantee the target bridge life, bridge maintenance activities such as local inspection and repair should be undertaken properly. However, this is a challenging task because there are various sources of uncertainty associated with aging bridges, train loads, environmental conditions, and maintenance work. Therefore, to perform optimal risk-based maintenance of railway bridges, it is essential to estimate the probabilistic fatigue life of a railway bridge and update the life information based on the results of local inspections and repair. Recently, a system reliability approach was proposed to evaluate the fatigue failure risk of structural systems and update the prior risk information in various inspection scenarios. However, this approach can handle only a constant-amplitude load and has limitations in considering a cyclic load with varying amplitude levels, which is the major loading pattern generated by train traffic. In addition, it is not feasible to update the prior risk information after bridges are repaired. In this research, the system reliability approach is further developed so that it can handle a varying-amplitude load and update the system-level risk of fatigue failure for railway bridges after inspection and repair. The proposed method is applied to a numerical example of an in-service railway bridge, and the effects of inspection and repair on the probabilistic fatigue life are discussed.

Probabilistic Fatigue Life Updating for Railway Bridges Based on Local Inspection and Repair

PubMed Central

Lee, Young-Joo; Kim, Robin E.; Suh, Wonho; Park, Kiwon

2017-01-01

Railway bridges are exposed to repeated train loads, which may cause fatigue failure. As critical links in a transportation network, railway bridges are expected to survive for a target period of time, but sometimes they fail earlier than expected. To guarantee the target bridge life, bridge maintenance activities such as local inspection and repair should be undertaken properly. However, this is a challenging task because there are various sources of uncertainty associated with aging bridges, train loads, environmental conditions, and maintenance work. Therefore, to perform optimal risk-based maintenance of railway bridges, it is essential to estimate the probabilistic fatigue life of a railway bridge and update the life information based on the results of local inspections and repair. Recently, a system reliability approach was proposed to evaluate the fatigue failure risk of structural systems and update the prior risk information in various inspection scenarios. However, this approach can handle only a constant-amplitude load and has limitations in considering a cyclic load with varying amplitude levels, which is the major loading pattern generated by train traffic. In addition, it is not feasible to update the prior risk information after bridges are repaired. In this research, the system reliability approach is further developed so that it can handle a varying-amplitude load and update the system-level risk of fatigue failure for railway bridges after inspection and repair. The proposed method is applied to a numerical example of an in-service railway bridge, and the effects of inspection and repair on the probabilistic fatigue life are discussed. PMID:28441768

Design Exception In-Service Monitoring Program Development

DOT National Transportation Integrated Search

2017-05-01

This study evaluates various possible program designs for in-service monitoring of design exceptions (DEs) for the Georgia Department of Transportation. The study recommends a multitier stepwise approach to the evaluation of DEs. Specifically, the pr...

Ultrasonic speech translator and communications system

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

Akerman, M.A.; Ayers, C.W.; Haynes, H.D.

1996-07-23

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system includes an ultrasonic transmitting device and an ultrasonic receiving device. The ultrasonic transmitting device accepts as input an audio signal such as human voice input from a microphone or tape deck. The ultrasonic transmitting device frequency modulatesmore » an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output. 7 figs.« less

Ultrasonic speech translator and communications system

DOEpatents

Akerman, M.A.; Ayers, C.W.; Haynes, H.D.

1996-07-23

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system includes an ultrasonic transmitting device and an ultrasonic receiving device. The ultrasonic transmitting device accepts as input an audio signal such as human voice input from a microphone or tape deck. The ultrasonic transmitting device frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output. 7 figs.

Ultrasonic speech translator and communications system

DOEpatents

Akerman, M. Alfred; Ayers, Curtis W.; Haynes, Howard D.

1996-01-01

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system (20) includes an ultrasonic transmitting device (100) and an ultrasonic receiving device (200). The ultrasonic transmitting device (100) accepts as input (115) an audio signal such as human voice input from a microphone (114) or tape deck. The ultrasonic transmitting device (100) frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device (200) converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output (250).

Perspectives on Preservice and Inservice Education.

ERIC Educational Resources Information Center

Rubin, Louis

This publication, part of the Professional Development series, focuses on teacher development programs. An overview of present programs indicates the need for educational innovations, a continuous link between preservice and inservice programs, a renewed concern for performance skills, and field experiences that reflect the reality of teaching.…

Ultrasonic Monitoring of the Interaction between Cement Matrix and Alkaline Silicate Solution in Self-Healing Systems.

PubMed

Ait Ouarabi, Mohand; Antonaci, Paola; Boubenider, Fouad; Gliozzi, Antonio S; Scalerandi, Marco

2017-01-07

Alkaline solutions, such as sodium, potassium or lithium silicates, appear to be very promising as healing agents for the development of encapsulated self-healing concretes. However, the evolution of their mechanical and acoustic properties in time has not yet been completely clarified, especially regarding their behavior and related kinetics when they are used in the form of a thin layer in contact with a hardened cement matrix. This study aims to monitor, using linear and nonlinear ultrasonic methods, the evolution of a sodium silicate solution interacting with a cement matrix in the presence of localized cracks. The ultrasonic inspection via linear methods revealed that an almost complete recovery of the elastic and acoustic properties occurred within a few days of healing. The nonlinear ultrasonic measurements contributed to provide further insight into the kinetics of the recovery due to the presence of the healing agent. A good regain of mechanical performance was ascertained through flexural tests at the end of the healing process, confirming the suitability of sodium silicate as a healing agent for self-healing cementitious systems.

Ultrasonic Bolt Gage

NASA Technical Reports Server (NTRS)

Gleman, Stuart M. (Inventor); Rowe, Geoffrey K. (Inventor)

1999-01-01

An ultrasonic bolt gage is described which uses a crosscorrelation algorithm to determine a tension applied to a fastener, such as a bolt. The cross-correlation analysis is preferably performed using a processor operating on a series of captured ultrasonic echo waveforms. The ultrasonic bolt gage is further described as using the captured ultrasonic echo waveforms to perform additional modes of analysis, such as feature recognition. Multiple tension data outputs, therefore, can be obtained from a single data acquisition for increased measurement reliability. In addition, one embodiment of the gage has been described as multi-channel, having a multiplexer for performing a tension analysis on one of a plurality of bolts.

75 FR 48997 - NUREG-1946, “Inservice Testing of Pumps and Valves, and Inservice Examination and Testing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-12

..., and Inservice Examination and Testing of Dynamic Restraints (Snubbers) at Nuclear Power Plants, Draft... Dynamic Restraints (Snubbers) at Nuclear Power Plants, Draft Report for Comment.'' DATES: Please submit... System (ADAMS): Publicly available documents created or received at the NRC are available electronically...

Radial vibration and ultrasonic field of a long tubular ultrasonic radiator.

PubMed

Shuyu, Lin; Zhiqiang, Fu; Xiaoli, Zhang; Yong, Wang; Jing, Hu

2013-09-01

The radial vibration of a metal long circular tube is studied analytically and its electro-mechanical equivalent circuit is obtained. Based on the equivalent circuit, the radial resonance frequency equation is derived. The theoretical relationship between the radial resonance frequency and the geometrical dimensions is studied. Finite element method is used to simulate the radial vibration and the radiated ultrasonic field and the results are compared with those from the analytical method. It is concluded that the radial resonance frequency for a solid metal rod is larger than that for a metal tube with the same outer radius. The radial resonance frequencies from the analytical method are in good agreement with those from the numerical method. Based on the acoustic field analysis, it is concluded that the long metal tube with small wall thickness is superior to that with large wall thickness in producing radial vibration and ultrasonic radiation. Therefore, it is expected to be used as an effective radial ultrasonic radiator in ultrasonic sewage treatment, ultrasonic antiscale and descaling and other ultrasonic liquid handling applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Women's Studies for Teachers and Administrators: A Packet of Inservice Education Materials.

ERIC Educational Resources Information Center

Froschl, Merle, Ed.; And Others

This packet of materials is designed for elementary and secondary teachers and administrators who are engaged in inservice education and interested in the movement to eliminate sexism in schools. Two major purposes of the packet are to help a school district start an inservice course on sexism in education and to show the potential of such a…

Qualification of the RSRM case membrane case-to-insulation bondline inspection using the Thiokol Corporation ultrasonic RSRM bondline inspection system

NASA Technical Reports Server (NTRS)

Cook, M.

1990-01-01

Qualification testing of Combustion Engineering's AMDATA Intraspect/98 Data Acquisition and Imaging System that applies to the redesigned solid rocket motor (RSRM) case membrane case-to-insulation bondline inspection was performed. Testing was performed at M-67, the Thiokol Corp. RSRM Assembly Facility. The purpose of the inspection was to verify the integrity of the case membrane case-to-insulation bondline. The case membrane scanner was calibrated on the redesigned solid rocket motor case segment calibration standard, which had an intentional 1.0 by 1.0 in. case-to-insulation unbond. The case membrane scanner was then used to scan a 20 by 20 in. membrane area of the case segment. Calibration of the scanner was then rechecked on the calibration standard to ensure that the calibration settings did not change during the case membrane scan. This procedure was successfully performed five times to qualify the unbond detection capability of the case membrane scanner.

Research on Ultrasonic Flaw Detection of Steel Weld in Spatial Grid Structure

NASA Astrophysics Data System (ADS)

Du, Tao; Sun, Jiandong; Fu, Shengguang; Zhang, Changquan; Gao, Qing

2017-06-01

The welding quality of spatial grid member is an important link in quality control of steel structure. The paper analyzed the reasons that the welding seam of small-bore pipe with thin wall grid structure is difficult to be detected by ultrasonic wave from the theoretical and practical aspects. A series of feasible detection methods was also proposed by improving probe and operation approaches in this paper, and the detection methods were verified by project cases. Over the years, the spatial grid structure is widely used the engineering by virtue of its several outstanding characteristics such as reasonable structure type, standard member, excellent space integrity and quick installation. The wide application of spatial grid structure brings higher requirements on nondestructive test of grid structure. The implementation of new Code for Construction Quality Acceptance of Steel Structure Work GB50205-2001 strengthens the site inspection of steel structure, especially the site inspection of ultrasonic flaw detection in steel weld. The detection for spatial grid member structured by small-bore and thin-walled pipes is difficult due to the irregular influence of sound pressure in near-field region of sound field, sound beam diffusion generated by small bore pipe and reduction of sensitivity. Therefore, it is quite significant to select correct detecting conditions. The spatial grid structure of welding ball and bolt ball is statically determinate structure with high-order axial force which is connected by member bars and joints. It is welded by shrouding or conehead of member bars and of member bar and bolt-node sphere. It is obvious that to ensure the quality of these welding positions is critical to the quality of overall grid structure. However, the complexity of weld structure and limitation of ultrasonic detection method cause many difficulties in detection. No satisfactory results will be obtained by the conventional detection technology, so some special

Effects of ultrasonic instrumentation on enamel surfaces with various defects.

PubMed

Kim, S-Y; Kang, M-K; Kang, S-M; Kim, H-E

2018-05-01

The aim of this study was to analyse the enamel damage caused by ultrasonic scaling of teeth with various enamel conditions that are difficult to identify by visual inspection, such as enamel cracks, early caries and resin restorations. In total, 120 tooth surfaces were divided into 4 experimental groups using a quantitative light-induced fluorescence-digital system: sound enamel group, enamel cracks group, early caries group and resin restoration group. A skilled dental hygienist performed ultrasonic scaling under a standardized set of conditions: a ≤ 15° angle between the scaler tip and tooth surface and 40-80 g of lateral pressure at the rate of 12 times/10 s. Following scaling, the depth of enamel damage was measured using a surface profilometer and observed using scanning electron microscopy (SEM). The damage depth was the greatest in the enamel cracks group (37.63 ± 34.42 μm), followed by the early caries group (26.81 ± 8.67 μm), resin restoration group (19.63 ± 6.73 μm) and the sound enamel group (17.00 ± 5.66 μm). The damage depth was significantly deeper in the enamel cracks and early caries groups than in the sound enamel group (P < .05). SEM clearly revealed enamel loss in the enamel cracks, early caries and resin restoration groups. The results of this study suggest that ultrasonic scaling can cause further damage to teeth with enamel cracks, early caries and resin restorations. Therefore, accurate identification of tooth conditions and calculus before the initiation of ultrasonic scaling is necessary to minimize damage. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Factors Underlying the Need for In-Service Development Programs in Student Personnel Work.

ERIC Educational Resources Information Center

Truitt, John W.

Definitions, objectives, and concepts of in-service development programs in student personnel work are discussed. A structured, in-service development program p"ovides: (1) continuity for constantly changing staff; (2) enhances orientation and upgrading of new staff; (3) increases staff morale through shared responsibility; (4) encourages…

Piping inspection instrument carriage with precise and repeatable position control and location determination

DOEpatents

Hapstack, M.; Talarek, T.R.; Zollinger, W.T.; Heckendorn, F.M. II; Park, L.R.

1994-02-15

An instrument carriage for inspection of piping comprises front and rear leg assemblies for engaging the interior of the piping and supporting and centering the carriage therein, and an instrumentation arm carried by a shaft system running from the front to rear leg assemblies. The shaft system has a screw shaft for moving the arm axially and a spline gear for moving the arm azimuthally. The arm has a pair of air cylinders that raise and lower a plate in the radial direction. On the plate are probes including an eddy current probe and an ultrasonic testing probe. The ultrasonic testing probe is capable of spinning 360[degree] about its axis. The instrument carriage uses servo motors and pressurized air cylinders for precise actuation of instrument components and precise, repeatable actuation of position control mechanisms. 8 figures.

The development of recent high-power ultrasonic transducers for Near-well ultrasonic processing technology.

PubMed

Wang, Zhenjun; Xu, Yuanming

2017-07-01

With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers for Near-well ultrasonic processing technology are summarized. Each field application of them are also given. The purpose of this paper is to provide reference for the further development of Near-well ultrasonic processing technology. With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers

Ultrasonics Equipped Crimp Tool: A New Technology for Aircraft Wiring Safety

NASA Technical Reports Server (NTRS)

Yost, William T.; Perey, Daniel F.; Cramer, Elliott

2006-01-01

We report on the development of a new measurement technique to quantitatively assess the condition of wire crimp connections. This ultrasonic (UT) method transmits high frequency sound waves through the joint under inspection. The wire-crimp region filters and scatters the ultrasonic energy as it passes through the crimp and wire. The resulting output (both time and frequency domains) provides a quantitative measure of the joint quality that is independent and unaffected by current. Crimps of poor mechanical and electrical quality will result in low temporal output and will distort the spectrum into unique and predictable patterns, depending on crimp "quality". This inexpensive, real-time measurement system can provide certification of crimps as they are made and recertification of existing wire crimps currently in service. The measurements for re-certification do not require that the wire be disconnected from its circuit. No other technology exists to measure in-situ the condition of wire joints (no electrical currents through the crimp are used in this analytical technique). We discuss the signals obtained from this instrument, and correlate these signals with destructive wire pull tests.

Program for establishing long-time flight service performance of composite materials in the center wing structure of C-130 aircraft. Phase 5: Flight service and inspection

NASA Technical Reports Server (NTRS)

Kizer, J. A.

1981-01-01

Inspections of the C-130 composite-reinforced center wings were conducted over the flight service monitoring period of more than six years. Twelve inspections were conducted on each of the two C-130H airplanes having composite reinforced center wing boxes. Each inspection consisted of visual and ultrasonic inspection of the selective boron-epoxy reinforced center wings which included the inspection of the boron-epoxy laminates and the boron-epoxy reinforcement/aluminum structure adhesive bondlines. During the flight service monitoring period, the two C-130H aircraft accumulated more than 10,000 flight hours and no defects were detected in the inspections over this period. The successful performance of the C-130H aircraft with composite-reinforced center wings allowed the transfer of the responsibilities of inspecting and maintaining these two aircraft to the U. S. Air Force.

Nonlinear Acoustic and Ultrasonic NDT of Aeronautical Components

NASA Astrophysics Data System (ADS)

Van Den Abeele, Koen; Katkowski, Tomasz; Mattei, Christophe

2006-05-01

In response to the demand for innovative microdamage inspection systems, with high sensitivity and undoubted accuracy, we are currently investigating the use and robustness of several acoustic and ultrasonic NDT techniques based on Nonlinear Elastic Wave Spectroscopy (NEWS) for the characterization of microdamage in aeronautical components. In this report, we illustrate the results of an amplitude dependent analysis of the resonance behaviour, both in time (signal reverberation) and in frequency (sweep) domain. The technique is applied to intact and damaged samples of Carbon Fiber Reinforced Plastics (CFRP) composites after thermal loading or mechanical fatigue. The method shows a considerable gain in sensitivity and an incontestable interpretation of the results for nonlinear signatures in comparison with the linear characteristics. For highly fatigued samples, slow dynamical effects are observed.

Ultrasonic Determination Of Recrystallization

NASA Technical Reports Server (NTRS)

Generazio, Edward R.

1988-01-01

State of recrystallization identified. Measurement of ultrasonic attenuation shows promise as means of detecting recrystallization in metal. Technique applicable to real-time acoustic monitoring of thermomechanical treatments. Starting with work-hardened material, one ultrasonically determines effect of annealing, using correlation between ultrasonic attenuation and temperature.

A View from the Field: Discipline-Based Art Education for In-Service Teachers.

ERIC Educational Resources Information Center

Day, Gary; Gillespie, Michael; Rosenberg, Martin; Sowell, Joanne; Thurber, Frances

1997-01-01

Describes the development of an evolving art content framework for the Nebraska Prairie Visions Institute in Discipline-Based Art Education (DBAE) for in-service teachers. Provides examples of some of the learning experiences and suggests how the outcomes might be significant for other in-service programs in DBAE. (DSK)

Optimization of an angle-beam ultrasonic approach for characterization of impact damage in composites

NASA Astrophysics Data System (ADS)

Henry, Christine; Kramb, Victoria; Welter, John T.; Wertz, John N.; Lindgren, Eric A.; Aldrin, John C.; Zainey, David

2018-04-01

Advances in NDE method development are greatly improved through model-guided experimentation. In the case of ultrasonic inspections, models which provide insight into complex mode conversion processes and sound propagation paths are essential for understanding the experimental data and inverting the experimental data into relevant information. However, models must also be verified using experimental data obtained under well-documented and understood conditions. Ideally, researchers would utilize the model simulations and experimental approach to efficiently converge on the optimal solution. However, variability in experimental parameters introduce extraneous signals that are difficult to differentiate from the anticipated response. This paper discusses the results of an ultrasonic experiment designed to evaluate the effect of controllable variables on the anticipated signal, and the effect of unaccounted for experimental variables on the uncertainty in those results. Controlled experimental parameters include the transducer frequency, incidence beam angle and focal depth.

Preservice and inservice teachers' knowledge of language constructs in Finland.

PubMed

Aro, Mikko; Björn, Piia Maria

2016-04-01

The aim of the study was to explore the Finnish preservice and inservice teachers' knowledge of language constructs relevant for literacy acquisition. A total of 150 preservice teachers and 74 inservice teachers participated in the study by filling out a questionnaire that assessed self-perceived expertise in reading instruction, knowledge of phonology and phonics, and knowledge of morphology. The inservice teachers outperformed the preservice teachers in knowledge of phonology and phonics, as well as morphology. Both groups' knowledge of morphology was markedly lower than their knowledge of phonology and phonics. Because early reading instruction does not focus on the morphological level of language but is phonics-based, this result was expected. However, the findings also revealed a lack of explicit knowledge of basic phonological constructs and less-than-optimal phonemic awareness skills in both groups. Problems in phonemic skills manifested mostly as responding to the phonological tasks based on orthographic knowledge, which reflects an overreliance on the one-to-one correspondence between graphemes and phonemes. The preservice teachers' perceptions of expertise were weakly related to their knowledge and skills. Among the inservice teachers, perceived expertise and knowledge of language constructs were completely unrelated. Although the study was exploratory, these findings suggest that within the Finnish teacher education there is a need to focus more on explicit content studies for language structures and the concepts relevant for literacy instruction, as well as phonological and phonemic skills.

Ultrasonic cleaning: Fundamental theory and application

NASA Technical Reports Server (NTRS)

Fuchs, F. John

1995-01-01

This presentation describes: the theory of ultrasonics, cavitation and implosion; the importance and application of ultrasonics in precision cleaning; explanations of ultrasonic cleaning equipment options and their application; process parameters for ultrasonic cleaning; and proper operation of ultrasonic cleaning equipment to achieve maximum results.

The acousto-ultrasonic approach

NASA Technical Reports Server (NTRS)

Vary, Alex

1987-01-01

The nature and underlying rationale of the acousto-ultrasonic approach is reviewed, needed advanced signal analysis and evaluation methods suggested, and application potentials discussed. Acousto-ultrasonics is an NDE technique combining aspects of acoustic emission methodology with ultrasonic simulation of stress waves. This approach uses analysis of simulated stress waves for detecting and mapping variations of mechanical properties. Unlike most NDE, acousto-ultrasonics is less concerned with flaw detection than with the assessment of the collective effects of various flaws and material anomalies. Acousto-ultrasonics has been applied chiefly to laminated and filament-wound fiber reinforced composites. It has been used to assess the significant strength and toughness reducing effects that can be wrought by combinations of essentially minor flaws and diffuse flaw populations. Acousto-ultrasonics assesses integrated defect states and the resultant variations in properties such as tensile, shear, and flexural strengths and fracture resistance. Matrix cure state, porosity, fiber orientation, fiber volume fraction, fiber-matrix bonding, and interlaminar bond quality are underlying factors.

Synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted with mixed hollow sphere template method

NASA Astrophysics Data System (ADS)

Gopi, D.; Indira, J.; Kavitha, L.; Sekar, M.; Mudali, U. Kamachi

Hydroxyapatite (HAP) is the main inorganic component of bone material and is widely used in various biomedical applications due to its excellent bioactivity and biocompatibility. In this paper, we have reported the synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted mixed template directed method. In this method glycine-acrylic acid (GLY-AA) hollow spheres were used as an organic template which could be prepared by mixing of glycine with acrylic acid. The as-synthesized HAP nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and tunnelling electron microscope (TEM) to investigate the nature of bonding, crystallinity, size and shape. The thermal stability of as-synthesized nanoparticles was also investigated by the thermo gravimetric analysis (TGA). The effect of ultrasonic irradiation time on the crystallinity and size of the HAP nanoparticles in presence of glycine-acrylic acid hollow spheres template were investigated. From the inspection of the above results it is confirmed that the crystallinity and size of the HAP nanoparticles decrease with increasing ultrasonic irradiation time. Hence the proposed synthesis strategy provides a facile pathway to obtain nano sized HAP with high quality, suitable size and morphology.

The Center for In-Service Education. Final Evaluation Report. Volume II. Part 1.

ERIC Educational Resources Information Center

Tennessee State Dept. of Education, Nashville.

This is an overview of the extensive in-service education inventory conducted as an integral portion of the planning contract for Models for In-Service Education supported by the Tennessee State Department of Education under Title III, Elementary and Secondary Education Act. The narrative descriptions are free of extensive statistical references…

In-Service Teachers' Sense of Agency after Participation in a Research Master Course

ERIC Educational Resources Information Center

Impedovo, Maria Antonietta

2016-01-01

In this paper, we investigate the in-service teachers "sense of agency" after their participation in a research master course. A semi-structured interview was administrated to nine in-service science teachers, coming from three different African countries: Zimbabwe, Lesotho, and Burkina Faso. All of them attended a European master course…

Alternate Welding Processes for In-Service Welding

DOT National Transportation Integrated Search

2009-04-24

Conducting weld repairs and attaching hot tap tees onto pressurized pipes has the advantage of avoiding loss of service and revenue. However, the risks involved with in-service welding need to be managed by ensuring that welding is performed in a rep...

Damage detection in hazardous waste storage tank bottoms using ultrasonic guided waves

NASA Astrophysics Data System (ADS)

Cobb, Adam C.; Fisher, Jay L.; Bartlett, Jonathan D.; Earnest, Douglas R.

2018-04-01

Detecting damage in storage tanks is performed commercially using a variety of techniques. The most commonly used inspection technologies are magnetic flux leakage (MFL), conventional ultrasonic testing (UT), and leak testing. MFL and UT typically involve manual or robotic scanning of a sensor along the metal surfaces to detect cracks or corrosion wall loss. For inspection of the tank bottom, however, the storage tank is commonly emptied to allow interior access for the inspection system. While there are costs associated with emptying a storage tank for inspection that can be justified in some scenarios, there are situations where emptying the tank is impractical. Robotic, submersible systems have been developed for inspecting these tanks, but there are some storage tanks whose contents are so hazardous that even the use of these systems is untenable. Thus, there is a need to develop an inspection strategy that does not require emptying the tank or insertion of the sensor system into the tank. This paper presents a guided wave system for inspecting the bottom of double-shelled storage tanks (DSTs), with the sensor located on the exterior side-wall of the vessel. The sensor used is an electromagnetic acoustic transducer (EMAT) that generates and receives shear-horizontal guided plate waves using magnetostriction principles. The system operates by scanning the sensor around the circumference of the storage tank and sending guided waves into the tank bottom at regular intervals. The data from multiple locations are combined using the synthetic aperture focusing technique (SAFT) to create a color-mapped image of the vessel thickness changes. The target application of the system described is inspection of DSTs located at the Hanford site, which are million-gallon vessels used to store nuclear waste. Other vessels whose exterior walls are accessible would also be candidates for inspection using the described approach. Experimental results are shown from tests on multiple

78 FR 71676 - NUREG-1482, Revision 2, “Guidelines for Inservice Testing at Nuclear Power Plants, Final Report”

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... subtitled ``Inservice Testing of Pumps and Valves, and Inservice Examination and Testing of Dynamic... the inservice examination and testing of dynamic restraints (snubbers). ADDRESSES: Please refer to... CONTACT section of this document. NRC's Agencywide Documents Access and Management System (ADAMS): You may...

Linear Array Ultrasonic Test Results from Alkali-Silica Reaction (ASR) Specimens

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

Clayton, Dwight A; Khazanovich, Dr. Lev; Salles, Lucio

2016-04-01

The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the variousmore » nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations.This report presents results of the ultrasound evaluation of four concrete slabs with varying levels of ASR damage present. This included an investigation of the experimental results, as well as a supplemental simulation considering the effect of ASR damage by elasto-dynamic wave propagation using a finite integration technique method. It was found that the Hilbert Transform Indicator (HTI), developed for quantification of freeze/thaw damage in concrete structures, could also be successfully utilized for quantification of ASR damage. internal microstructure flaws, and reinforcement locations.« less

Development of an ultrasonic weld inspection system based on image processing and neural networks

NASA Astrophysics Data System (ADS)

Roca Barceló, Fernando; Jaén del Hierro, Pedro; Ribes Llario, Fran; Real Herráiz, Julia

2018-04-01

Several types of discontinuities and defects may be present on a weld, thus leading to a considerable reduction of its resistance. Therefore, ensuring a high welding quality and reliability has become a matter of key importance for many construction and industrial activities. Among the non-destructive weld testing and inspection techniques, the time-of-flight diffraction (TOFD) arises as a very safe (no ionising radiation), precise, reliable and versatile practice. However, this technique presents a relevant drawback, associated to the appearance of speckle noise that should be addressed. In this regard, this paper presents a new, intelligent and automatic method for weld inspection and analysis, based on TOFD, image processing and neural networks. The developed system is capable of detecting weld defects and imperfections with accuracy, and classify them into different categories.

National Study of State Universities and Land Grant Colleges: Off Campus Inservice Activities.

ERIC Educational Resources Information Center

Seldin, Clement A.

Information concerning off-campus inservice activity (OCIA) at state universities and land grant colleges in the United States was surveyed. There was a 92.5 percent response rate to questionnaires sent to 107 deans of schools, colleges, and departments of education. Inservice activities were considered to be courses, workshops, needs assessments,…

High frequency copolymer ultrasonic transducer array of size-effective elements

NASA Astrophysics Data System (ADS)

Decharat, Adit; Wagle, Sanat; Habib, Anowarul; Jacobsen, Svein; Melandsø, Frank

2018-02-01

A layer-by-layer deposition method for producing dual-layer ultrasonic transducers from piezoelectric copolymers has been developed. The method uses a combination of customized and standard processing to obtain 2D array transducers with electrical connection of the individual elements routed directly to the rear of the substrate. A numerical model was implemented to study basic parameters effecting the transducer characteristics. Key elements of the array were characterized and evaluated, demonstrating its viability of 2D imaging. Signal reproducibility of the prototype array was studied by characterizing the variations of the center frequency (≈42 MHz) and bandwidth (≈25 MHz) of the acoustic. Object identification was also tested and parameterized by acoustic-field beamwidth as well as proper scan step size. Simple tests to illustrate a benefit of multi-element scan on lowering the inspection time were conducted. Structural imaging of the test structure underneath multi-layered wave media (glass plate and distilled water) was also performed. The prototype presented in this work is an important step towards realizing an inexpensive, compact array of individually operated copolymer transducers that can serve in a fast/volumetric high frequency (HF) ultrasonic scanning platform.

Application of nonlinear ultrasonics to inspection of stainless steel for dry storage

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

Ulrich, Timothy James II; Anderson, Brain E.; Remillieux, Marcel C.

This report summarized technical work conducted by LANL staff an international collaborators in support of the UFD Storage Experimentation effort. The focus of the current technical work is on the detection and imaging of a failure mechanism known as stress corrosion cracking (SCC) in stainless steel using the nonlinear ultrasonic technique known as TREND. One of the difficulties faced in previous work is in finding samples that contain realistically sized SCC. This year such samples were obtained from EPRI. Reported here are measurements made on these samples. One of the key findings is the ability to detect subsurface changes tomore » the direction in which a crack is penetrating into the sample. This result follows from last year's report that demonstrated the ability of TREND techniques to image features below the sample surface. A new collaboration was established with AGH University of Science and Technology, Krakow, Poland.« less

Processing ultrasonic inspection data from multiple scan patterns for turbine rotor weld build-up evaluations

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

Guan, Xuefei; Zhou, S. Kevin; Rasselkorde, El Mahjoub

The study presents a data processing methodology for weld build-up using multiple scan patterns. To achieve an overall high probability of detection for flaws with different orientations, an inspection procedure with three different scan patterns is proposed. The three scan patterns are radial-tangential longitude wave pattern, axial-radial longitude wave pattern, and tangential shear wave pattern. Scientific fusion of the inspection data is implemented using volume reconstruction techniques. The idea is to perform spatial domain forward data mapping for all sampling points. A conservative scheme is employed to handle the case that multiple sampling points are mapped to one grid location.more » The scheme assigns the maximum value for the grid location to retain the largest equivalent reflector size for the location. The methodology is demonstrated and validated using a realistic ring of weld build-up. Tungsten balls and bars are embedded to the weld build-up during manufacturing process to represent natural flaws. Flat bottomed holes and side drilled holes are installed as artificial flaws. Automatic flaw identification and extraction are demonstrated. Results indicate the inspection procedure with multiple scan patterns can identify all the artificial and natural flaws.« less

Processing ultrasonic inspection data from multiple scan patterns for turbine rotor weld build-up evaluations

NASA Astrophysics Data System (ADS)

Guan, Xuefei; Rasselkorde, El Mahjoub; Abbasi, Waheed; Zhou, S. Kevin

2015-03-01

The study presents a data processing methodology for weld build-up using multiple scan patterns. To achieve an overall high probability of detection for flaws with different orientations, an inspection procedure with three different scan patterns is proposed. The three scan patterns are radial-tangential longitude wave pattern, axial-radial longitude wave pattern, and tangential shear wave pattern. Scientific fusion of the inspection data is implemented using volume reconstruction techniques. The idea is to perform spatial domain forward data mapping for all sampling points. A conservative scheme is employed to handle the case that multiple sampling points are mapped to one grid location. The scheme assigns the maximum value for the grid location to retain the largest equivalent reflector size for the location. The methodology is demonstrated and validated using a realistic ring of weld build-up. Tungsten balls and bars are embedded to the weld build-up during manufacturing process to represent natural flaws. Flat bottomed holes and side drilled holes are installed as artificial flaws. Automatic flaw identification and extraction are demonstrated. Results indicate the inspection procedure with multiple scan patterns can identify all the artificial and natural flaws.

In-Service Middle and High School Mathematics Teachers: Geometric Reasoning Stages and Gender

ERIC Educational Resources Information Center

Halat, Erdogan

2008-01-01

The purpose of this current study was to investigate the reasoning stages of in-service middle and high school mathematics teachers in geometry. There was a total of 148 in-service middle and high school mathematics teachers involved in the study. Participants' geometric reasoning stages were determined through a multiple-choice geometry test. The…

ULTRASONIC NEUTRON DOSIMETER

DOEpatents

Truell, R.; de Klerk, J.; Levy, P.W.

1960-02-23

A neutron dosimeter is described which utilizes ultrasonic waves in the megacycle region for determination of the extent of neutron damage in a borosilicate glass through ultrasonic wave velocity and attenuation measurements before and after damage.

Ultrasonic Imaging System

NASA Technical Reports Server (NTRS)

Youngquist, Robert C. (Inventor); Moerk, Steven (Inventor)

1999-01-01

An imaging system is described which can be used to either passively search for sources of ultrasonics or as an active phase imaging system. which can image fires. gas leaks, or air temperature gradients. This system uses an array of ultrasonic receivers coupled to an ultrasound collector or lens to provide an electronic image of the ultrasound intensity in a selected angular region of space. A system is described which includes a video camera to provide a visual reference to a region being examined for ultrasonic signals.

Evaluating of In-Service Training Activities for Teachers in Turkey: A Critical Analysis

ERIC Educational Resources Information Center

Yolcu, Hüseyin; Kartal, Sadik

2017-01-01

The aim of this study is to examine the in-service training activities organized by the Ministry of Education of Turkey for the last 15 years (between 2001 and 2015). Two main starting points were identified in commentaries on in-service training; (1) Teacher needs which are part of the field of teacher training (2) Technological developments…

Pre-Service and In-Service Science Teachers' Conceptions of the Nature of Science

ERIC Educational Resources Information Center

Buaraphan, Khajornsak

2010-01-01

The author explores the history of nature of science beliefs among pre-service and in-service teachers primarily in the United States and Thailand and compares this history to findings in a current study being conducted in Thailand. Two research questions were used to guide this current study: What are pre-service and in-service science teachers'…

In-Service Education: A Blueprint for Action

ERIC Educational Resources Information Center

Keller, Arnold J.

1978-01-01

Inservice teacher education is the logical catalyst to any process of school improvement but school board members and school administrators must insure that their forthcoming efforts fulfill three important criteria: (1) Shared decision-making responsibilities with recognized representatives of the teaching staff, preferably at the individual…

Graduate and Inservice Education. [SITE 2002 Section].

ERIC Educational Resources Information Center

Crawford, Caroline M., Ed.

This document contains the papers on graduate and inservice education from the SITE (Society for Information Technology & Teacher Education) 2002 conference. Topics covered include: Geographic Information Systems in teacher education; re-certification and accreditation; construction of a Web site by graduate teacher education students; Web-based…

Persistent Problems and Promising Solutions in Inservice Education. Report of Selected REGI Project Directors.

ERIC Educational Resources Information Center

Grigsby, Greg

This report summarizes and presents information from interviews with 22 National Inservice Network project directors. The purpose was to identify problems and solutions encountered in directing regular education inservice (REGI) projects. The projects were sponsored by institutions of higher education, state and local education agencies, and an…

Professional Education In-Service Needs of Agriculture Instructors in Iowa Postsecondary Area Vocational Schools.

ERIC Educational Resources Information Center

Byler, Bennie L.; Lindahl, Thomas J.

The primary objective of the study was to identify the professional inservice education needs of agriculture instructors in postsecondary area vocational schools, and determine if differences exist among instructors and adminstrative personnel regarding perceived instructor inservice needs. The population consisted of all of the Iowa community…

Proceedings of the Management Information Systems October 1973 In-Service Session (Atlanta, Georgia, October 18-19, 1973).

ERIC Educational Resources Information Center

Institute for Services to Education, Inc., Washington, DC. TACTICS Management Information Systems Directorate.

The October 1973 in-service session held in Atlanta, Georgia was the first of two in-service sessions held as a follow-up to the Summer 1973 Information Management Training Institute held in Nashville, Tennessee in June 1973. The purpose of the in-service sessions was to ascertain the progress made as a result of the summer programs by the various…

Ultrasonics in Dentistry

NASA Astrophysics Data System (ADS)

Walmsley, A. D.

Ultrasonic instruments have been used in dentistry since the 1950's. Initially they were used to cut teeth but very quickly they became established as an ultrasonic scaler which was used to remove deposits from the hard tissues of the tooth. This enabled the soft tissues around the tooth to return to health. The ultrasonic vibrations are generated in a thin metal probe and it is the working tip that is the active component of the instrument. Scanning laser vibrometry has shown that there is much variability in their movement which is related to the shape and cross sectional shape of the probe. The working instrument will also generate cavitation and microstreaming in the associated cooling water. This can be mapped out along the length of the instrument indicating which are the active areas. Ultrasonics has also found use for cleaning often inaccessible or different surfaces including root canal treatment and dental titanium implants. The use of ultrasonics to cut bone during different surgical techniques shows considerable promise. More research is indicated to determine how to maximize the efficiency of such instruments so that they are more clinically effective.

Application of Linear Array Imaging Techniques to the Real-Time Inspection of Airframe Structures and Substructures

NASA Technical Reports Server (NTRS)

Miller, James G. (Principal Investigator)

1996-01-01

Current concern for ensuring, the air-worthiness of the aging commercial air fleet has prompted the establishment of broad-agency programs to develop NDT technologies that address specific aging-aircraft issues. One of the crucial technological needs that has been identified is the development of rapid, quantitative systems for depot-level inspection of bonded aluminum lap joints on aircraft. Research results for characterization of disbond and corrosion based on normal-incidence pulse-echo measurement geometries are showing promise, but are limited by the single-site nature of the measurement which requires manual or mechanical scanning to inspect an area. One approach to developing efficient systems may be to transfer specific aspects of current medical imaging technology to the NDT arena. Ultrasonic medical imaging, systems offer many desirable attributes for large scale inspection. They are portable, provide real-time imaging, and have integrated video tape recorder and printer capabilities available for documentation and post-inspection review. Furthermore, these systems are available at a relatively low cost (approximately $50,000 to $200,000) and can be optimized for use with metals with straight-forward modifications.

Ultrasonic Polishing

NASA Technical Reports Server (NTRS)

Gilmore, Randy

1993-01-01

The ultrasonic polishing process makes use of the high-frequency (ultrasonic) vibrations of an abradable tool which automatically conforms to the work piece and an abrasive slurry to finish surfaces and edges on complex, highly detailed, close tolerance cavities in materials from beryllium copper to carbide. Applications range from critical deburring of guidance system components to removing EDM recast layers from aircraft engine components to polishing molds for forming carbide cutting tool inserts or injection molding plastics. A variety of materials including tool steels, carbides, and even ceramics can be successfully processed. Since the abradable tool automatically conforms to the work piece geometry, the ultrasonic finishing method described offers a number of important benefits in finishing components with complex geometries.

Ultrasonic search wheel probe

DOEpatents

Mikesell, Charles R.

1978-01-01

A device is provided for reducing internal reflections from the tire of an ultrasonic search wheel probe or from within the material being examined. The device includes a liner with an anechoic chamber within which is an ultrasonic transducer. The liner is positioned within the wheel and includes an aperture through which the ultrasonic sound from the transducer is directed.

Empowering Education: A New Model for In-service Training of Nursing Staff.

PubMed

Chaghari, Mahmud; Saffari, Mohsen; Ebadi, Abbas; Ameryoun, Ahmad

2017-01-01

In-service training of nurses plays an indispensable role in improving the quality of inpatient care. Need to enhance the effectiveness of in-service training of nurses is an inevitable requirement. This study attempted to design a new optimal model for in-service training of nurses. This qualitative study was conducted in two stages during 2015-2016. In the first stage, the Grounded Theory was adopted to explore the process of training 35 participating nurses. The sampling was initially purposeful and then theoretically based on emerging concept. Data were collected through interview, observation and field notes. Moreover, the data were analyzed through Corbin-Strauss method and the data were coded through MAXQDA-10. In the second stage, the findings were employed through 'Walker and Avants strategy for theory construction so as to design an optimal model for in-service training of nursing staff. In the first stage, there were five major themes including unsuccessful mandatory education, empowering education, organizational challenges of education, poor educational management, and educational-occupational resiliency. Empowering education was the core variable derived from the research, based on which a grounded theory was proposed. The new empowering education model was composed of self-directed learning and practical learning. There are several strategies to achieve empowering education, including the fostering of searching skills, clinical performance monitoring, motivational factors, participation in the design and implementation, and problem-solving approach. Empowering education is a new model for in-service training of nurses, which matches the training programs with andragogical needs and desirability of learning among the staff. Owing to its practical nature, the empowering education can facilitate occupational tasks and achieving greater mastery of professional skills among the nurses.

In-Service Preschool Teachers' Thoughts about Technology and Technology Use in Early Educational Settings

ERIC Educational Resources Information Center

Kara, Nuri; Cagiltay, Kursat

2017-01-01

The purpose of this study is to understand in-service preschool teachers' thoughts about technology and technology use in early educational settings. Semi-structured interviews were conducted with 18 in-service preschool teachers. These teachers were selected from public and private preschools. Convenient sampling was applied because teachers who…

Gestalt Workshops: Suggested In-Service Training for Teachers.

ERIC Educational Resources Information Center

Fiordo, Richard

1981-01-01

Fritz Perls' Gestalt Workshops are explained and recommended for inservice training for teachers. Since Gestalt Workshops increase their participants' growth, awareness, and integration personally and environmentally, their benefit to classroom teachers would be direct and dramatic. (Author)

Inservice Training Packet: Auditory Discrimination Listening Skills.

ERIC Educational Resources Information Center

Florida Learning Resources System/CROWN, Jacksonville.

Intended to be used as the basis for a brief inservice workshop, the auditory discrimination/listening skills packet provides information on ideas, materials, and resources for remediating auditory discrimination and listening skill deficits. Included are a sample prescription form, tests of auditory discrimination, and a list of auditory…

Detection and reconstruction of solidification cracks - Laser ultrasonic measurements during the continuous casting process of aluminum

NASA Astrophysics Data System (ADS)

Mitter, Thomas; Grün, Hubert; Roither, Jürgen; Betz, Andreas; Bozorgi, Salar; Reitinger, Bernhard; Burgholzer, Peter

2014-05-01

In the continuous casting process the avoidance and rapid detection of occurring solidification cracks in the slab is a crucial issue, in particular for the maintenance of a high quality level in further production processes. Due to the elevated temperatures of the slab surface a remote sensing non-destructive tool for quality inspection is required, which is also applicable for the harsh industrial environment. In this work the application of laser ultrasound (LUS) technique during the continuous casting process in industrial environment is shown. The proof of principle of the detection of the centered solidification cracks is shown by pulse-echo measurements with laser ultrasonic equipment for inline quality inspection. Preliminary examinations in the lab of different casted samples have shown the distinguishability of slabs with and without any solidification cracks. Furthermore the damping of the bulk wave has been used for the prediction of the dimension of the crack. With an adapted "synthetic aperture focusing technique" (SAFT) algorithm the image reconstruction of multiple measurements at different positions around the circumference has provided enough information for the estimation of the localization and extension of the centered solidification cracks. Subsequent first measurements using this laser ultrasonic setup during the continuous casting of aluminum were carried out and showed the proof of principle in an industrial environment with elevated temperatures, dust, cooling water and vibrations.

Non-destructive inspection protocol for reinforced concrete barriers and bridge railings

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

Chintakunta, Satish R.; Boone, Shane D.

Reinforced concrete highway barriers and bridge railings serve to prevent errant vehicles from departing the travel way at grade separations. Despite the important role that they play in maintaining safety and their ubiquitous nature, barrier inspection rarely moves beyond visual inspection. In August 2008, a tractor-trailer fatally departed William Preston Lane, Jr. Memorial Bridge after it dislodged a section of the bridge barrier. Investigations following the accident identified significant corrosion of the anchor bolts attaching the bridge railing to the bridge deck. As a result of the information gathered during its investigation of the accident, the National Transportation Safety Boardmore » (NTSB) made recommendations to the Federal Highway Administration concerning Non-Destructive Evaluation (NDE) of concrete bridge railings. The Center for nondestructive evaluation (NDE) at Turner Fairbank Highway Research Center in McLean, VA is currently evaluating feasibility of using four technologies - ground penetrating radar (GPR), ultrasonic pulse-echo, digital radiography and infrared thermal imaging methods to develop bridge inspection methods that augment visual inspections, offer reliable measurement techniques, and are practical, both in terms of time and cost, for field inspection work. Controlled samples containing predefined corrosion levels in reinforcing steel were embedded at barrier connection points for laboratory testing. All four NDE techniques were used in the initial phase I testing. An inspection protocol for detecting and measuring the corrosion of reinforced steel embedded in the anchorage system will be developed as part of phase II research. The identified technologies shall be further developed for field testing utilizing a structure with a barrier in good condition and a structure with a barrier in poor condition.« less

Non-destructive inspection protocol for reinforced concrete barriers and bridge railings

NASA Astrophysics Data System (ADS)

Chintakunta, Satish R.; Boone, Shane D.

2014-02-01

Reinforced concrete highway barriers and bridge railings serve to prevent errant vehicles from departing the travel way at grade separations. Despite the important role that they play in maintaining safety and their ubiquitous nature, barrier inspection rarely moves beyond visual inspection. In August 2008, a tractor-trailer fatally departed William Preston Lane, Jr. Memorial Bridge after it dislodged a section of the bridge barrier. Investigations following the accident identified significant corrosion of the anchor bolts attaching the bridge railing to the bridge deck. As a result of the information gathered during its investigation of the accident, the National Transportation Safety Board (NTSB) made recommendations to the Federal Highway Administration concerning Non-Destructive Evaluation (NDE) of concrete bridge railings. The Center for nondestructive evaluation (NDE) at Turner Fairbank Highway Research Center in McLean, VA is currently evaluating feasibility of using four technologies - ground penetrating radar (GPR), ultrasonic pulse-echo, digital radiography and infrared thermal imaging methods to develop bridge inspection methods that augment visual inspections, offer reliable measurement techniques, and are practical, both in terms of time and cost, for field inspection work. Controlled samples containing predefined corrosion levels in reinforcing steel were embedded at barrier connection points for laboratory testing. All four NDE techniques were used in the initial phase I testing. An inspection protocol for detecting and measuring the corrosion of reinforced steel embedded in the anchorage system will be developed as part of phase II research. The identified technologies shall be further developed for field testing utilizing a structure with a barrier in good condition and a structure with a barrier in poor condition.

Perception of Classroom and Branch Teachers Working in Primary Schools towards In-Service Education

ERIC Educational Resources Information Center

Demir, Mehmet Kaan

2012-01-01

The need for in-service education for teachers is recognized by all who are concerned with improvement of school practice. A successful in-service education involves many different kinds of activities. This study aims to determine the perceptions of classroom and branch (social studies, science and technology, foreign language, physical education…

Addressing Adolescent Depression in Schools: Evaluation of an In-Service Training for School Staff in the United States

ERIC Educational Resources Information Center

Valdez, Carmen R.; Budge, Stephanie L.

2012-01-01

This study evaluated an adolescent depression in-service training for school staff in the United States. A total of 252 school staff (e.g., teachers, principals, counselors) completed assessments prior to and following the in-service and a subsample of these staff participated in focus groups following the in-service and three months later.…

Design optimization of embedded ultrasonic transducers for concrete structures assessment.

PubMed

Dumoulin, Cédric; Deraemaeker, Arnaud

2017-08-01

In the last decades, the field of structural health monitoring and damage detection has been intensively explored. Active vibration techniques allow to excite structures at high frequency vibrations which are sensitive to small damage. Piezoelectric PZT transducers are perfect candidates for such testing due to their small size, low cost and large bandwidth. Current ultrasonic systems are based on external piezoelectric transducers which need to be placed on two faces of the concrete specimen. The limited accessibility of in-service structures makes such an arrangement often impractical. An alternative is to embed permanently low-cost transducers inside the structure. Such types of transducers have been applied successfully for the in-situ estimation of the P-wave velocity in fresh concrete, and for crack monitoring. Up to now, the design of such transducers was essentially based on trial and error, or in a few cases, on the limitation of the acoustic impedance mismatch between the PZT and concrete. In the present study, we explore the working principles of embedded piezoelectric transducers which are found to be significantly different from external transducers. One of the major challenges concerning embedded transducers is to produce very low cost transducers. We show that a practical way to achieve this imperative is to consider the radial mode of actuation of bulk PZT elements. This is done by developing a simple finite element model of a piezoelectric transducer embedded in an infinite medium. The model is coupled with a multi-objective genetic algorithm which is used to design specific ultrasonic embedded transducers both for hard and fresh concrete monitoring. The results show the efficiency of the approach and a few designs are proposed which are optimal for hard concrete, fresh concrete, or both, in a given frequency band of interest. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of Programmed Inservice Training on Dialects.

ERIC Educational Resources Information Center

Maxwell, John; And Others

Development of this 6-part inservice program making major use of programed instruction began in 1969 with the objective of modifying classroom teacher behavior in the direction of individualizing the instruction of students learning to control standard English. A review of literature on dialects gave some guidance toward determining the…

Desegregation and Inservice Education: A General Bibliography.

ERIC Educational Resources Information Center

Southwest Educational Development Lab., Austin, TX.

This bibliography of desegregation and inservice education literature was developed by the WIEDS (Ways to Improve Education in Desegregated Schools) Project in Austin, Texas. This bibliography is said to be a by-product of research done on successful desegregation/integration strategies which could be applied to the planning of staff and…

Inservice Training as an Instrument for Change.

ERIC Educational Resources Information Center

Lefforge, Orland S.

This plan for improving community college instruction uses an in-service training program as a primary vehicle for change. The objectives to be achieved are: (1) develop a climate for educational innovation, (2) develop individual initiative in professional growth, (3) coordinate training resources, faculty efforts, and college goals, and (4)…

Rural Inservice Education: Staples Teacher Center Style.

ERIC Educational Resources Information Center

Krueger, Rick

In its two-year existence, the federally funded Staples Teacher Center (STC) in Minnesota has had a significant impact on improving classroom instruction and staff development activities in a rural setting, proving that teacher centers are a most effective delivery system for inservice education in sparsely populated areas. Services are rendered…

Aspects of In-Service Education in England.

ERIC Educational Resources Information Center

Nist, Joan Stidham

This paper outlines the growth and development of teacher centers in England. These centers grew out of a general dissatisfaction on the part of classroom teachers with existing inservice programs. It was the feeling that certain priorities for teachers were being overlooked, such as methods of dealing with learning difficulties, class…

Reinforcing In-Service Teachers Education via ICT

ERIC Educational Resources Information Center

Thorsteinsson, Gisli

2012-01-01

Earlier educational models have not managed to take into account novel contextual and mobile methods of learning with the advances in technology-mediated learning. The article firstly reports an educational approach, namely, future innovative in-service teacher education in Europe (ICE-ED). This project was supported by the European Union Comenius…

Pre-Service and In-Service Preschool Teachers' Views Regarding Creativity in Early Childhood Education

ERIC Educational Resources Information Center

Alkus, Simge; Olgan, Refika

2014-01-01