Optimum design of bolted composite lap joints under mechanical and thermal loading

NASA Astrophysics Data System (ADS)

Kradinov, Vladimir Yurievich

A new approach is developed for the analysis and design of mechanically fastened composite lap joints under mechanical and thermal loading. Based on the combined complex potential and variational formulation, the solution method satisfies the equilibrium equations exactly while the boundary conditions are satisfied by minimizing the total potential. This approach is capable of modeling finite laminate planform dimensions, uniform and variable laminate thickness, laminate lay-up, interaction among bolts, bolt torque, bolt flexibility, bolt size, bolt-hole clearance and interference, insert dimensions and insert material properties. Comparing to the finite element analysis, the robustness of the method does not decrease when modeling the interaction of many bolts; also, the method is more suitable for parametric study and design optimization. The Genetic Algorithm (GA), a powerful optimization technique for multiple extrema functions in multiple dimensions search spaces, is applied in conjunction with the complex potential and variational formulation to achieve optimum designs of bolted composite lap joints. The objective of the optimization is to acquire such a design that ensures the highest strength of the joint. The fitness function for the GA optimization is based on the average stress failure criterion predicting net-section, shear-out, and bearing failure modes in bolted lap joints. The criterion accounts for the stress distribution in the thickness direction at the bolt location by applying an approach utilizing a beam on an elastic foundation formulation.

KSC-2013-3008

NASA Image and Video Library

2013-05-14

CAPE CANAVERAL, Fla. -- Inside the Launch Equipment Test Facility at NASA’s Kennedy Space in Florida, a second firing of the escape hold down post has occurred during a pyrotechnic bolt test on the Orion ground test vehicle. Lockheed Martin performed tests over a series of days on the explosive bolts that separate Orion from the launch abort system. Data was collected on the effect of shock waves on Orion during the explosive bolt separation. Orion is the exploration spacecraft designed to carry crews to space beyond low Earth orbit. It will provide emergency abort capability, sustain the crew during the space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of the Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on a Space Launch System rocket. For more information, visit http://www.nasa.gov/orion. Photo credit: NASA/Jim Grossmann

Euthanasia of Cattle: Practical Considerations and Application.

PubMed

Shearer, Jan Keith

2018-04-17

Acceptable methods for the euthanasia of cattle include overdose of an anesthetic, gunshot and captive bolt. The use of anesthetics for euthanasia is costly and complicates carcass disposal. These issues can be avoided by use of a physical method such as gunshot or captive bolt; however, each requires that certain conditions be met to assure an immediate loss of consciousness and death. For example, the caliber of firearm and type of bullet are important considerations when gunshot is used. When captive bolt is used, a penetrating captive bolt loaded with the appropriate powder charge and accompanied by a follow up (adjunctive) step to assure death are required. The success of physical methods also requires careful selection of the anatomic site for entry of a “free bullet” or “bolt” in the case of penetrating captive bolt. Disease eradication plans for animal health emergencies necessitate methods of euthanasia that will facilitate rapid and efficient depopulation of animals while preserving their welfare to the greatest extent possible. A portable pneumatic captive bolt device has been developed and validated as effective for use in mass depopulation scenarios. Finally, while most tend to focus on the technical aspects of euthanasia, it is extremely important that no one forget the human cost for those who may be required to perform the task of euthanasia on a regular basis. Symptoms including depression, grief, sleeplessness and destructive behaviors including alcoholism and drug abuse are not uncommon for those who participate in the euthanasia of animals.

Effects of bolt-hole contact on bearing-bypass damage-onset strength

NASA Technical Reports Server (NTRS)

Crews, John H., Jr.; Naik, Rajiv A.

1991-01-01

A combined experimental and analytical study was conducted to investigate the effects of bolt-hole contact on the bearing bypass strength of a graphite-epoxy laminate. Tests were conducted on specimens consisting of 16-ply quasi-isotropic T300/5208 laminates with a centrally located hole. Bearing loads were applied through a clearance-fit steel bolt. Damage onset strength and damage mode were determined for each test case. A finite element procedure was used to calculate the bolt-hole stresses and bolt contact for each test case. A finite element procedure was used to calculate the bolt-hole stresses and bolt contact for each measured damage-onset strength. For the tension bearing-bypass cases tested, the bolt contact half-angle was approximately 60 degrees at damage onset. For compression, the contact angle was 20 degrees as the bypass load increased. A corresponding decrease in the bearing damage onset strength was attributed to the decrease in contact angle which made the bearing loads more severe. Hole boundary stresses were also computed by superimposing stresses for separate bearing and bypass loading. Stresses at the specimen net section were accurately approximated by the superposition procedure. However, the peak bearing stresses had large errors because the bolt contact angles were not represented correctly. For compression, peak bearing stress errors of nearly 50 percent were calculated.

Advanced Concepts for Composite Structure Joints and Attachment Fittings. Volume I. Design and Evaluation.

DTIC Science & Technology

1981-11-01

interlaminar tension). The analysis is also influenced by other factors such as bolt location, washer/bolt size, fastener pattern, laminate thickness, corner...to reduce the cost of tooling were also studied. These include: * Pultrusion dies for under $5, 000 * Stable, accurate, low-cost chopped-fiber phenolic ...fittings were state-of- the-art methods developed for laminated composite plates, shells, beams, and columns as used in analyses of discontinuities, edge

[Experimental study of tendon graft fixation in anterior cruciate ligament reconstruction with cortical press-fit bolt in rabbits].

PubMed

Qi, Wei; Li, Chun-bao; Wang, Jun-liang; Zhu, Juan-li; Liu, Yu-jie

2013-05-21

To explore the histological outcomes of tendon-bone healing in anterior cruciate ligament (ACL) reconstruction with cortical press-fit bolt (CPB). Twenty-four healthy female or male New Zealand White rabbits (2-3 months old) underwent bilateral ACL reconstruction with extensor digitorum longus tendon. A random method was used to decide one knee would receive the routine ACL reconstruction (control group) and another cortical press-fit bolt fixation (experimental group). After general anesthesia, extensor digitorum longus tendon was harvested and ACL reconstruction performed. All animals were sacrificed at 4, 8 and 12 weeks postoperation. Radiological and histological examinations were made at each timepoint. The specimens were stained with different methods to observe the pathological changes of tendon graft, bone tunnel and cortical press-fit bolt. More revascularization and massive new bone were found in tendon-bone junction of experimental group at 4, 8 and 12 weeks postoperation. The circum-graft new vessel proportion of the experimental and control groups were 0.48 ± 0.12 and 0.26 ± 0.05 respectively (P < 0.05). In the experimental group, more cartilage cells were present in tendon-bone junction at 12 weeks and the circum-graft new bone areas in two groups were 0.41 ± 0.11 and 0.21 ± 0.10 mm(2) respectively (P < 0.05). Cortical press-fit blot may improve tendon-bone healing after ACL reconstruction in rabbits. The application prospects of this procedure are promising.

PIXE Analysis of Metal Hull Bolts From HMB DeBraak

NASA Astrophysics Data System (ADS)

Correll, Francis D.; Cole, Lord K.; Slater, Charles J.; Vanhoy, Jeffrey R.; Fithian, Charles H.

2009-03-01

HMB DeBraak was a 16-gun British brig-sloop that sank in a squall on May 25, 1798 off Cape Henlopen, Delaware. Silt covered the wooden hull shortly after it sank, preserving it until DeBraak was raised in 1986. The items recovered from the ship include metal bolts that held the hull together. We used PIXE to measure the compositions of 45 of the bolts and found that they are nearly pure copper (98.3% on average), with most also containing small amounts of iron (0.87%), nickel (0.039%), arsenic (0.43%), silver (0.089%), lead (0.18%), and bismuth (0.12%). A few contain a little indium, tin, or antimony, but none contain zinc above the quantization level. The compositions are similar to those reported for 18th-century English copper, but different from several copper alloys also used to make hull bolts. We conclude that, when DeBraak was last fitted out in 1795-1797, the Royal Navy was still using bolts similar to William Forbes's mechanically hardened pure copper bolts. Forbes's process represents the successful innovation and application of new technology in Royal Navy ships during the wars of the late 18th century.

Alignment Pins for Assembling and Disassembling Structures

NASA Technical Reports Server (NTRS)

Campbell, Oliver C.

2008-01-01

Simple, easy-to-use, highly effective tooling has been devised for maintaining alignment of bolt holes in mating structures during assembly and disassembly of the structures. The tooling was originally used during removal of a body flap from the space shuttle Atlantis, in which misalignments during removal of the last few bolts could cause the bolts to bind in their holes. By suitably modifying the dimensions of the tooling components, the basic design of the tooling can readily be adapted to other structures that must be maintained in alignment. The tooling includes tapered, internally threaded alignment pins designed to fit in the bolt holes in one of the mating structures, plus a draw bolt and a cup that are used to install or remove each alignment pin. In preparation for disassembly of two mating structures, external supports are provided to prevent unintended movement of the structures. During disassembly of the structures, as each bolt that joins the structures is removed, an alignment pin is installed in its place. Once all the bolts have been removed and replaced with pins, the pins maintain alignment as the structures are gently pushed or pulled apart on the supports. In assembling the two structures, one reverses the procedure described above: pins are installed in the bolt holes, the structures are pulled or pushed together on the supports, then the pins are removed and replaced with bolts. The figure depicts the tooling and its use. To install an alignment pin in a bolt hole in a structural panel, the tapered end of the pin is inserted from one side of the panel, the cup is placed over the pin on the opposite side of the panel, the draw bolt is inserted through the cup and threaded into the pin, the draw bolt is tightened to pull the pin until the pin is seated firmly in the hole, then the draw bolt and cup are removed, leaving the pin in place. To remove an alignment pin, the cup is placed over the pin on the first-mentioned side of the panel, the draw bolt is inserted through the cup and threaded into the pin, then the draw bolt is tightened to pull the pin out of the hole.

Experimental analysis of thread movement in bolted connections due to vibrations

NASA Technical Reports Server (NTRS)

Ramey, G. ED; Jenkins, Robert C.

1994-01-01

The objective of this study was to identify the main design parameters contributing to loosening of bolts due to vibration and to identify their relative importance and degree of contribution to bolt loosening. Vibration testing was conducted on a shaketable with a controlled-random input in the dynamic testing laboratory of the Structural Test Division of MSFC. Test specimens which contained one test bolt were vibrated for a fixed amount of time and percentage of pre-load loss was measured. Each specimen tested implemented some combination of eleven design parameters as dictated by the design of experiment methodology employed. The eleven design parameters were: bolt size (diameter), lubrication on bolt, hole tolerance, initial pre-load, nut locking device, grip length, thread pitch, lubrication between mating materials, class of fit, joint configuration and mass of configuration. These parameters were chosen for this experiment because they are believed to be the design parameters having the greatest impact on bolt loosening. Two values of each design parameter were used and each combination of parameters tested was subjected to two different directions of vibration and two different g-levels of vibration. One replication was made for each test to gain some indication of experimental error and repeatability and to give some degree of statistical credibility to the data, resulting in a total of 96 tests being performed. The results of the investigation indicated that nut locking devices, joint configuration, fastener size, and mass of configuration were significant in bolt loosening due to vibration. The results of this test can be utilized to further research the complex problem of bolt loosening due to vibration.

Correlations for Boundary-Layer Transition on Mars Science Laboratory Entry Vehicle Due to Heat-Shield Cavities

NASA Technical Reports Server (NTRS)

Hollis, Brian R.; Liechty, Derek S.

2008-01-01

The influence of cavities (for attachment bolts) on the heat-shield of the proposed Mars Science Laboratory entry vehicle has been investigated experimentally and computationally in order to develop a criterion for assessing whether the boundary layer becomes turbulent downstream of the cavity. Wind tunnel tests were conducted on the 70-deg sphere-cone vehicle geometry with various cavity sizes and locations in order to assess their influence on convective heating and boundary layer transition. Heat-transfer coefficients and boundary-layer states (laminar, transitional, or turbulent) were determined using global phosphor thermography.

46 CFR 61.20-18 - Examination requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... fitted) and propeller designed in accordance with American Bureau of Shipping standards to reduce stress... visual inspection of the entire shaft. (c) On tailshafts with a propeller fitted to the shaft by means of a coupling flange, the flange, the fillet at the propeller end, and each coupling bolt must be...

46 CFR 61.20-18 - Examination requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... fitted) and propeller designed in accordance with American Bureau of Shipping standards to reduce stress... visual inspection of the entire shaft. (c) On tailshafts with a propeller fitted to the shaft by means of a coupling flange, the flange, the fillet at the propeller end, and each coupling bolt must be...

46 CFR 61.20-18 - Examination requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... fitted) and propeller designed in accordance with American Bureau of Shipping standards to reduce stress... visual inspection of the entire shaft. (c) On tailshafts with a propeller fitted to the shaft by means of a coupling flange, the flange, the fillet at the propeller end, and each coupling bolt must be...

46 CFR 61.20-18 - Examination requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... fitted) and propeller designed in accordance with American Bureau of Shipping standards to reduce stress... visual inspection of the entire shaft. (c) On tailshafts with a propeller fitted to the shaft by means of a coupling flange, the flange, the fillet at the propeller end, and each coupling bolt must be...

46 CFR 61.20-18 - Examination requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... fitted) and propeller designed in accordance with American Bureau of Shipping standards to reduce stress... visual inspection of the entire shaft. (c) On tailshafts with a propeller fitted to the shaft by means of a coupling flange, the flange, the fillet at the propeller end, and each coupling bolt must be...

Stress analysis method for clearance-fit joints with bearing-bypass loads

NASA Technical Reports Server (NTRS)

Naik, R. A.; Crews, J. H., Jr.

1989-01-01

Within a multi-fastener joint, fastener holes may be subjected to the combined effects of bearing loads and loads that bypass the hole to be reacted elsewhere in the joint. The analysis of a joint subjected to search combined bearing and bypass loads is complicated by the usual clearance between the hole and the fastener. A simple analysis method for such clearance-fit joints subjected to bearing-bypass loading has been developed in the present study. It uses an inverse formulation with a linear elastic finite-element analysis. Conditions along the bolt-hole contact arc are specified by displacement constraint equations. The present method is simple to apply and can be implemented with most general purpose finite-element programs since it does not use complicated iterative-incremental procedures. The method was used to study the effects of bearing-bypass loading on bolt-hole contact angles and local stresses. In this study, a rigid, frictionless bolt was used with a plate having the properties of a quasi-isotropic graphite/epoxy laminate. Results showed that the contact angle as well as the peak stresses around the hole and their locations were strongly influenced by the ratio of bearing and bypass loads. For single contact, tension and compression bearing-bypass loading had opposite effects on the contact angle. For some compressive bearing-bypass loads, the hole tended to close on the fastener leading to dual contact. It was shown that dual contact reduces the stress concentration at the fastener and would, therefore, increase joint strength in compression. The results illustrate the general importance of accounting for bolt-hole clearance and contact to accurately compute local bolt-hole stresses for combined bearings and bypass loading.

Thermal conductance measurements of bolted copper joints for SuperCDMS

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

Schmitt, R.; Tatkowski, Greg; Ruschman, M.

2015-09-01

Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60 mK to 26 K. This testing was performed to validate an initial design basis for the SuperCDMS experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Results obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.

High temperature turbine engine structure

DOEpatents

Boyd, Gary L.

1992-01-01

A hybrid ceramic/metallic fastener (bolt) includes a headed ceramic shank carrying a metallic end termination fitting. A conventional cap screw threadably engages the termination fitting to apply tensile force to the fastener.

High temperature turbine engine structure

DOEpatents

Boyd, Gary L.

1991-01-01

A hybrid ceramic/metallic fastener (bolt) includes a headed ceramic shank carrying a metallic end termination fitting. A conventional cap screw threadably engages the termination fitting to apply tensile force to the fastener.

PIXE Analysis of Metal Hull Bolts From HMB DeBraak

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

Correll, Francis D.; Cole, Lord K.; Slater, Charles J.

2009-03-10

HMB DeBraak was a 16-gun British brig-sloop that sank in a squall on May 25, 1798 off Cape Henlopen, Delaware. Silt covered the wooden hull shortly after it sank, preserving it until DeBraak was raised in 1986. The items recovered from the ship include metal bolts that held the hull together. We used PIXE to measure the compositions of 45 of the bolts and found that they are nearly pure copper (98.3% on average), with most also containing small amounts of iron (0.87%), nickel (0.039%), arsenic (0.43%), silver (0.089%), lead (0.18%), and bismuth (0.12%). A few contain a little indium,more » tin, or antimony, but none contain zinc above the quantization level. The compositions are similar to those reported for 18th-century English copper, but different from several copper alloys also used to make hull bolts. We conclude that, when DeBraak was last fitted out in 1795-1797, the Royal Navy was still using bolts similar to William Forbes's mechanically hardened pure copper bolts. Forbes's process represents the successful innovation and application of new technology in Royal Navy ships during the wars of the late 18th century.« less

75 FR 63045 - Airworthiness Directives; BAE SYSTEMS (OPERATIONS) LIMITED Model BAe 146 and Avro 146-RJ Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-14

... the fitting and wing structure. Checking the nuts with a suitable torque spanner to the specifications in the torque figures shown in Table 2. of the Accomplishment Instructions of BAE SYSTEMS (OPERATIONS... installed, and Doing either an ultrasonic inspection for damaged bolts or torque check of the tension bolts...

78 FR 28190 - Foreign-Trade Zone (FTZ) 134-Chattanooga, Tennessee; Notification of Proposed Production Activity...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-14

... domestic sales, Komatsu would be able to choose the duty rates during customs entry procedures that apply... abroad include: cleaning agents; glues; adhesives; adhesive plates; O-rings; rubber bolts/rods; hoses...

VIEW SHOWING THE ENTRY THROUGH THE RETAINING WALL (FOREGROUND) TO ...

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

VIEW SHOWING THE ENTRY THROUGH THE RETAINING WALL (FOREGROUND) TO THE CONCRETE SLAB. NOTE THE 1¾" MOUNTING BOLTS FOR THE STEEL PLATE BASE OF THE 5" GUN, SET IN THE GUN BLOCK. STEEL REINFORCING RODS PROTRUDING FROM THE BROKEN TOPS OF THE RETAINING WALLS ARE ALSO VISIBLE. VIEW FACING EAST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, South Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

Thermal conductance measurements of bolted copper joints for SuperCDMS

DOE PAGES

Schmitt, R. L.; Tatkowski, G.; Ruschman, M.; ...

2015-04-28

Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60 mK to 26 K. This testing was performed to validate an initial design basis for the SuperCDMS experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Finally, the results we obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.

On the performance of Usain Bolt in the 100 m sprint

NASA Astrophysics Data System (ADS)

Hernández Gómez, J. J.; Marquina, V.; Gómez, R. W.

2013-09-01

Many university texts on mechanics consider the effect of air drag force, using the slowing down of a parachute as an example. Very few discuss what happens when the drag force is proportional to both u and u2. In this paper we deal with a real problem to illustrate the effect of both terms on the speed of a runner: a theoretical model of the world-record 100 m sprint of Usain Bolt during the 2009 World Championships in Berlin is developed, assuming a drag force proportional to u and to u2. The resulting equation of motion is solved and fitted to the experimental data obtained from the International Association of Athletics Federations, which recorded Bolt's position with a laser velocity guard device. It is worth noting that our model works only for short sprints.

78 FR 23468 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-19

... requires repetitive inspections for cracking of the elevator actuator fittings. This new AD requires, for... actuator fitting or incorrectly installed bolts to the actuator fitting, which could lead to the elevator... Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE...

77 FR 46340 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-03

... repetitive inspections for cracking of the elevator actuator fittings. Since we issued that AD, the... actuator fitting or incorrectly installed bolts to the actuator fitting, which could lead to the elevator... submitting comments. Fax: 202-493-2251. Mail: U.S. Department of Transportation, Docket Operations, M-30...

Experimental analysis of thread movement in bolted connections due to vibrations

NASA Technical Reports Server (NTRS)

Ramsey, G. ED; Jenkins, Robert C.

1995-01-01

This is the final report of research project NAS8-39131 #33 sponsored by NASA's George C. Marshall Space Flight Center (MSFC) and carried out by the Civil Engineering Department of Auburn University (Auburn, Alabama) and personnel of MSFC. The objective of this study was to identify the main design parameters contributing to the loosening of bolts due to vibration and to identify their relative importance and degree of contribution to bolt loosening. Vibration testing was conducted on a shaketable with a controlled-random input in the dynamic testing laboratory of the Structural Test Division of MSFC. Test specimens which contained one test bolt were vibrated for a fixed amount of time and a percentage of pre-load loss was measured. Each specimen tested implemented some combination of eleven design parameters as dictated by the design of experiment methodology employed. The eleven design parameters were: bolt size (diameter), lubrication on bolt, hole tolerance, initial pre-load, nut locking device, grip length, thread pitch, lubrication between mating materials, class of fit, joint configuration, and mass of configuration. These parameters were chosen for this experiment because they are believed to be the design parameters having the greatest impact on bolt loosening. Two values of each design parameter were used and each combination of parameters tested was subjected to two different directions of vibration and two different g-levels of vibration. One replication was made for each test to gain some indication of experimental error and repeatability and to give some degree of statistical credibility to the data, resulting in a total of 96 tests being performed. The results of the investigation indicated that nut locking devices, joint configuration, fastener size, and mass of configuration were significant in bolt loosening due to vibration. The results of this test can be utilized to further research the complex problem of bolt loosening due to vibration.

Thermal Interference Fit Anode Assembly for Cathodic Protection

DTIC Science & Technology

2018-02-22

than an inside diameter of the cylindrical anode, is subject to the low temperature for a minimum of six hours and preferably twenty- four hours to...degrees Fahrenheit after a minimum of six hours and preferably twenty-four hours. The anode 10 is immediately fused to the mounting bolt 20 by hand...degrees Fahrenheit after a minimum of six hours and preferably twenty-four hours. The anode is then hand pressed onto the mounting bolt to bottom out on the non-anodized face in order to form a single fused assembly.

Euthanasia of Cattle: Practical Considerations and Application

PubMed Central

Shearer, Jan Keith

2018-01-01

Simple Summary Methods recognized as acceptable for the euthanasia of cattle include overdose of an anesthetic, gunshot and captive bolt. The most common injectable anesthetic agent used for euthanasia is pentobarbital and while it may be the preferred method for euthanasia in sensitive situations, it creates significant challenges for disposal of animal remains. Gunshot and captive bolt are the more common methods used on farms and ranches because they are inexpensive, humane and do not complicate carcass disposal. Firearms must be of the proper caliber and loaded with the proper ammunition. Captive bolt, equipped with a penetrating bolt, is to be used on adult animals, whereas the non-penetrating (mushroom head) bolt should be reserved for use in calves (three months of age or less). In addition to selection of the proper firearm or captive bolt, successful euthanasia requires use of the proper anatomic site and adjunctive steps to assure death. The indicators of unconsciousness and death must be clearly understood and confirmed in all situations involving euthanasia. Tools for the efficient depopulation of a large feedlot, dairy or beef cattle operation as may be required in a national animal health emergency situation have been developed and validated as effective. Finally, the human impact of euthanasia cannot be underestimated. Symptoms of mental illness including depression, grief, sleeplessness and destructive behaviors including alcoholism and drug abuse are not uncommon for those who participate in the euthanasia of animals. Abstract Acceptable methods for the euthanasia of cattle include overdose of an anesthetic, gunshot and captive bolt. The use of anesthetics for euthanasia is costly and complicates carcass disposal. These issues can be avoided by use of a physical method such as gunshot or captive bolt; however, each requires that certain conditions be met to assure an immediate loss of consciousness and death. For example, the caliber of firearm and type of bullet are important considerations when gunshot is used. When captive bolt is used, a penetrating captive bolt loaded with the appropriate powder charge and accompanied by a follow up (adjunctive) step to assure death are required. The success of physical methods also requires careful selection of the anatomic site for entry of a “free bullet” or “bolt” in the case of penetrating captive bolt. Disease eradication plans for animal health emergencies necessitate methods of euthanasia that will facilitate rapid and efficient depopulation of animals while preserving their welfare to the greatest extent possible. A portable pneumatic captive bolt device has been developed and validated as effective for use in mass depopulation scenarios. Finally, while most tend to focus on the technical aspects of euthanasia, it is extremely important that no one forget the human cost for those who may be required to perform the task of euthanasia on a regular basis. Symptoms including depression, grief, sleeplessness and destructive behaviors including alcoholism and drug abuse are not uncommon for those who participate in the euthanasia of animals. PMID:29673140

Structural health monitoring technology for bolted carbon-carbon thermal protection panels

NASA Astrophysics Data System (ADS)

Yang, Jinkyu

2005-12-01

The research in this dissertation is motivated by the need for reliable inspection technologies for the detection of bolt loosening in Carbon-Carbon (C-C) Thermal Protection System (TPS) panels on Space Operation Vehicles (SOV) using minimal human intervention. A concept demonstrator of the Structural Health Monitoring (SHM) system was developed to autonomously detect the degradation of the mechanical integrity of the standoff C-C TPS panels. This system assesses the torque levels of the loosened bolts in the C-C TPS panel, as well as identifies the location of those bolts accordingly. During the course of building the proposed SHM prototype, efforts have been focused primarily on developing a trustworthy diagnostic scheme and a responsive sensor suite. Based on the microcontact conditions and damping phenomena of ultrasonic waves across the bolted joints, an Attenuation-based Diagnostic Method was proposed to assess the fastener integrity by observing the attenuation patterns of the resultant sensor signals. Parametric model studies and prototype testing validated the theoretical explanation of the attenuation-based method. Once the diagnostic scheme was determined, the implementation of a sensor suite was the next step. A new PZT-embedded sensor washer was developed to enhance remote sensing capability and achieve sufficient sensitivity by guiding diagnostic waves primarily through the inspection areas. The sensor-embedded washers replace the existing washers to constitute the sensor network, as well as to avoid jeopardizing the integrity of the original fastener components. After sensor design evolution and appropriate algorithm development, verification tests were conducted using a shaker and a full-scale oven, which simulated the acoustic and thermal environments during the re-entry process, respectively. The test results revealed that the proposed system successfully identifies the loss of the preload for the bolted joints that were loosened. The sensors were also found to be durable under the cyclic mechanical and thermal loads without major failures.

75 FR 74001 - Foreign-Trade Zone 72-Indianapolis, IN, Application for Subzone, GEA Bloomington Production...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-30

... fittings, rubber gaskets, screws, bolts, hinges, brackets, metal plates, compressors, filters, taps, valves... exported. On its domestic sales, GEA Bloomington would be able to choose the duty rates during customs...

Optimally analyzing and implementing of bolt fittings in steel structure based on ANSYS

NASA Astrophysics Data System (ADS)

Han, Na; Song, Shuangyang; Cui, Yan; Wu, Yongchun

2018-03-01

ANSYS simulation software for its excellent performance become outstanding one in Computer-aided Engineering (CAE) family, it is committed to the innovation of engineering simulation to help users to shorten the design process. First, a typical procedure to implement CAE was design. The framework of structural numerical analysis on ANSYS Technology was proposed. Then, A optimally analyzing and implementing of bolt fittings in beam-column join of steel structure was implemented by ANSYS, which was display the cloud chart of XY-shear stress, the cloud chart of YZ-shear stress and the cloud chart of Y component of stress. Finally, ANSYS software simulating results was compared with the measured results by the experiment. The result of ANSYS simulating and analyzing is reliable, efficient and optical. In above process, a structural performance's numerical simulating and analyzing model were explored for engineering enterprises' practice.

78 FR 34288 - Airworthiness Directives; Eurocopter France Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-07

... attaching fittings. If more than a 20 percent tightening torque load loss is discovered, the ASBs require... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2013... detect the torque loss of the bolts that secure the MGB bar attaching fittings and to prevent cracks that...

Investigation on the Influence of Abutment Pressure on the Stability of Rock Bolt Reinforced Roof Strata Through Physical and Numerical Modeling

NASA Astrophysics Data System (ADS)

Kang, Hongpu; Li, Jianzhong; Yang, Jinghe; Gao, Fuqiang

2017-02-01

In underground coal mining, high abutment loads caused by the extraction of coal can be a major contributor to many rock mechanic issues. In this paper, a large-scale physical modeling of a 2.6 × 2.0 × 1.0 m entry roof has been conducted to investigate the fundamentals of the fracture mechanics of entry roof strata subjected to high abutment loads. Two different types of roof, massive roof and laminated roof, are considered. Rock bolt system has been taken into consideration. A distinct element analyses based on the physical modeling conditions have been performed, and the results are compared with the physical results. The physical and numerical models suggest that under the condition of high abutment loads, the massive roof and the laminated roof fail in a similar pattern which is characterized as vertical tensile fracturing in the middle of the roof and inclined shear fracturing initiated at the roof and rib intersections and propagated deeper into the roof. Both the massive roof and the laminated roof collapse in a shear sliding mode shortly after shear fractures are observed from the roof surface. It is found that shear sliding is a combination of tensile cracking of intact rock and sliding on bedding planes and cross joints. Shear sliding occurs when the abutment load is much less than the compressive strength of roof.

A stochastic Iwan-type model for joint behavior variability modeling

NASA Astrophysics Data System (ADS)

Mignolet, Marc P.; Song, Pengchao; Wang, X. Q.

2015-08-01

This paper focuses overall on the development and validation of a stochastic model to describe the dissipation and stiffness properties of a bolted joint for which experimental data is available and exhibits a large scatter. An extension of the deterministic parallel-series Iwan model for the characterization of the force-displacement behavior of joints is first carried out. This new model involves dynamic and static coefficients of friction differing from each other and a broadly defined distribution of Jenkins elements. Its applicability is next investigated using the experimental data, i.e. stiffness and dissipation measurements obtained in harmonic testing of 9 nominally identical bolted joints. The model is found to provide a very good fit of the experimental data for each bolted joint notwithstanding the significant variability of their behavior. This finding suggests that this variability can be simulated through the randomization of only the parameters of the proposed Iwan-type model. The distribution of these parameters is next selected based on maximum entropy concepts and their corresponding parameters, i.e. the hyperparameters of the model, are identified using a maximum likelihood strategy. Proceeding with a Monte Carlo simulation of this stochastic Iwan model demonstrates that the experimental data fits well within the uncertainty band corresponding to the 5th and 95th percentiles of the model predictions which well supports the adequacy of the modeling effort.

Pivoting-Head Wrench

NASA Technical Reports Server (NTRS)

Bradley, Glen L.

1993-01-01

Wrench ends pivot so it can be used to loosen or tighten nuts or bolts in confined spaces. One end equipped with open-end socket; other end, with double-hexagon socket. Heads pivot on pins. Pins fit tightly so heads do not flop; friction on pins sufficient to hold heads in positions until rotated intentionally.

Is there a bone-nail specific entry point? Automated fit quantification of tibial nail designs during the insertion for six different nail entry points.

PubMed

Amarathunga, J P; Schuetz, M A; Yarlagadda, K V D; Schmutz, B

2015-04-01

Intramedullary nailing is the standard fixation method for displaced diaphyseal fractures of tibia. Selection of the correct nail insertion point is important for axial alignment of bone fragments and to avoid iatrogenic fractures. However, the standard entry point (SEP) may not always optimise the bone-nail fit due to geometric variations of bones. This study aimed to investigate the optimal entry for a given bone-nail pair using the fit quantification software tool previously developed by the authors. The misfit was quantified for 20 bones with two nail designs (ETN and ETN-Proximal Bend) related to the SEP and 5 entry points which were 5 mm and 10 mm away from the SEP. The SEP was the optimal entry point for 50% of the bones used. For the remaining bones, the optimal entry point was located 5 mm away from the SEP, which improved the overall fit by 40% on average. However, entry points 10 mm away from the SEP doubled the misfit. The optimised bone-nail fit can be achieved through the SEP and within the range of a 5 mm radius, except posteriorly. The study results suggest that the optimal entry point should be selected by considering the fit during insertion and not only at the final position. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Boundary Layer Transition Correlations and Aeroheating Predictions for Mars Smart Lander

NASA Technical Reports Server (NTRS)

Hollis, Brian R.; Liechty, Derek S.

2002-01-01

Laminar and turbulent perfect-gas air, Navier-Stokes computations have been performed for a proposed Mars Smart Lander entry vehicle at Mach 6 over a free stream Reynolds number range of 6.9 x 10(exp 6)/m to 2.4 x 10(exp 7)/m (2.1 x 10(exp 6)/ft to 7.3 x 10(exp 6)/ft) for angles-of-attack of 0-deg, 11-deg, 16-deg, and 20-deg, and comparisons were made to wind tunnel heating data obtained a t the same conditions. Boundary layer edge properties were extracted from the solutions and used to correlate experimental data on the effects of heat-shield penetrations (bolt-holes where the entry vehicle would be attached to the propulsion module during transit to Mars) on boundary-layer transition. A non-equilibrium Martian-atmosphere computation was performed for the peak heating point on the entry trajectory in order to determine if the penetrations would produce boundary-layer transition by using this correlation.

Boundary Layer Transition Correlations and Aeroheating Predictions for Mars Smart Lander

NASA Technical Reports Server (NTRS)

Hollis, Brian R.; Liechty, Derek S.

2002-01-01

Laminar and turbulent perfect-gas air, Navier-Stokes computations have been performed for a proposed Mars Smart Lander entry vehicle at Mach 6 over a free stream Reynolds number range of 6.9 x 10(exp 6/m to 2.4 x 10(exp 7)m(2.1 x 10(exp 6)/ft to 7.3 x 10(exp 6)ft) for angles-of-attack of 0-deg, 11-deg, 16-deg, and 20-deg, and comparisons were made to wind tunnel heating data obtained at the same conditions. Boundary layer edge properties were extracted from the solutions and used to correlate experimental data on the effects of heat-shield penetrations (bolt-holes where the entry vehicle would be attached to the propulsion module during transit to Mars) on boundary-layer transition. A non-equilibrium Martian-atmosphere computation was performed for the peak heating point on the entry trajectory in order to determine if the penetrations would produce boundary-layer transition by using this correlation.

49 CFR 1248.101 - Commodity codes required.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Hardware. 343 Plumbing Fixtures and Heating Apparatus, Except Electric. 3433 Heating equipment, except electric. 344 Fabricated structural metal products. 3441 Fabricated structural metal products. 345 Bolts... fabricated pipe fittings. 35 Machinery, Except Electrical. 351 Engines and Turbines. 352 Farm Machinery and...

49 CFR 1248.101 - Commodity codes required.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Hardware. 343 Plumbing Fixtures and Heating Apparatus, Except Electric. 3433 Heating equipment, except electric. 344 Fabricated structural metal products. 3441 Fabricated structural metal products. 345 Bolts... fabricated pipe fittings. 35 Machinery, Except Electrical. 351 Engines and Turbines. 352 Farm Machinery and...

49 CFR 1248.101 - Commodity codes required.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Hardware. 343 Plumbing Fixtures and Heating Apparatus, Except Electric. 3433 Heating equipment, except electric. 344 Fabricated structural metal products. 3441 Fabricated structural metal products. 345 Bolts... fabricated pipe fittings. 35 Machinery, Except Electrical. 351 Engines and Turbines. 352 Farm Machinery and...

49 CFR 1248.101 - Commodity codes required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Hardware. 343 Plumbing Fixtures and Heating Apparatus, Except Electric. 3433 Heating equipment, except electric. 344 Fabricated structural metal products. 3441 Fabricated structural metal products. 345 Bolts... fabricated pipe fittings. 35 Machinery, Except Electrical. 351 Engines and Turbines. 352 Farm Machinery and...

46 CFR 50.25-1 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subchapter. (b) Plate, bar stock, pipe, tube, pipe joining fittings (tees, elbows, reducers, etc.), bolting... or the cognizant Officer in Charge, Marine Inspection. (e) Components designed for hydraulic service... tested hydraulic components is granted by the Marine Safety Center or the cognizant Officer in Charge...

78 FR 14290 - Privacy Act of 1974; System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-05

... Fitness File (June 11, 1997, 62 FR 31793). * * * * * Changes: System ID: Delete entry and replace with ``F036 AF A1 I.'' System Name: Delete entry and replace with ``Air Force Fitness Program.'' System location: Delete entry and replace with ``Air Force Fitness Management System (AFFMS) is located at Defense...

Recruit Fitness as a Predictor of Police Academy Graduation.

PubMed

Shusko, M; Benedetti, L; Korre, M; Eshleman, E J; Farioli, A; Christophi, C A; Kales, S N

2017-10-01

Suboptimal recruit fitness may be a risk factor for poor performance, injury, illness, and lost time during police academy training. To assess the probability of successful completion and graduation from a police academy as a function of recruits' baseline fitness levels at the time of academy entry. Retrospective study where all available records from recruit training courses held (2006-2012) at all Massachusetts municipal police academies were reviewed and analysed. Entry fitness levels were quantified from the following measures, as recorded at the start of each training class: body composition, push-ups, sit-ups, sit-and-reach, and 1.5-mile run-time. The primary outcome of interest was the odds of not successfully graduating from an academy. We used generalized linear mixed models in order to fit logistic regression models with random intercepts for assessing the probability of not graduating, based on entry-level fitness. The primary analyses were restricted to recruits with complete entry-level fitness data. The fitness measures most strongly associated with academy failure were lesser number of push-ups completed (odds ratio [OR] = 5.2, 95% confidence interval [CI] 2.3-11.7, for 20 versus 41-60 push-ups) and slower run times (OR = 3.8, 95% CI 1.8-7.8, [1.5 mile run time of ≥15'20″] versus [12'33″ to 10'37″]). Baseline pushups and 1.5-mile run-time showed the best ability to predict successful academy graduation, especially when considered together. Future research should include prospective validation of entry-level fitness as a predictor of subsequent police academy success. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine.

Audio-based bolt-loosening detection technique of bolt joint

NASA Astrophysics Data System (ADS)

Zhang, Yang; Zhao, Xuefeng; Su, Wensheng; Xue, Zhigang

2018-03-01

Bolt joint, as the commonest coupling structure, is widely used in electro-mechanical system. However, it is the weakest part of the whole system. The increase of preload tension force can raise the reliability and strength of the bolt joint. Therefore, the pretension force is one of the most important factors to ensure the stability of bolt joint. According to the way of generating pretension force, the pretension force can be monitored by bolt torque, degrees and elongation. The existing bolt-loosening monitoring methods all require expensive equipment, which greatly restricts the practicality of the bolt-loosening monitoring. In this paper, a new method of bolt-loosening detection technique based on audio is proposed. The sound that bolt is hit by a hammer is recorded on the Smartphone, and the collected audio signal is classified and identified by support vector machine algorithm. First, a verification test was designed and the results show that this new method can identify the damage of bolt looseness accurately. Second, a variety of bolt-loosening was identified. The results indicate that this method has a high accuracy in multiclass classification of the bolt looseness. This bolt-loosening detection technique based on audio not only can reduce the requirements of technical and professional experience, but also make bolt-loosening monitoring simpler and easier.

My 65 years in acoustics

NASA Astrophysics Data System (ADS)

Beranek, Leo L.

2004-05-01

My entry into acoustics began as research assistant to Professor F. V. Hunt at Harvard University. I received my doctorate in 1940 and directed the Electro-Acoustic Laboratory at Harvard from October 1940 until September 1945. In 1947, I became a tenured associate professor at MIT, and, with Richard H. Bolt, formed the consulting firm Bolt and Beranek, that later included Robert B. Newman, becoming BBN. My most significant contributions before 1970 were design of wedge-lined anechoic chambers, systemization of noise reduction in ventilation systems, design of the world's largest muffler for the testing of supersonic jet engines at NASA's Lewis Laboratory in Cleveland, speech interference level, NC noise criterion curves, heading New York Port Authority's noise study that resulted in mufflers on jet aircraft, and steep aircraft climb procedures, and publishing books titled, Acoustical Measurements, Acoustics, Noise Reduction, Noise and Vibration Control, and Music, Acoustics and Architecture. As President of BBN, I supervised the formation of the group that built and operated the ARPANET (1969), which, when split in two (using TCP/IP protocol) became the INTERNET (1984). Since then, I have written two books on Concert Halls and Opera Houses and have consulted on four concert halls and an opera house.

Metallurgical failure analysis of MH-1A reactor core hold-down bolts. Final report

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

Hawthorne, J.R.; Watson, H.E.

1976-11-01

The Naval Research Laboratory has performed a failure analysis on two MH-1A reactor core hold-down bolts that broke in service. Adherence to fabrication specifications, post-service properties and possible causes of bolt failure were investigated. The bolt material was verified as 17-4PH precipitation hardening stainless steel. Measured bolt dimensions also were in accordance with fabrication drawing specifications. Bolt failure occurred in the region of a locking pin hole which reduced the bolt net section by 47 percent. The failure analysis indicates that the probable cause of failure was net section overloading resulting from a lateral bending force on the bolt. Themore » analysis indicates that net section overloading could also have resulted from combined tensile stresses (bolt preloading plus differential thermal expansion). Recommendations are made for improved bolting.« less

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 2: High pressure oxidizer turbo-pump turbine end bearing analysis

NASA Technical Reports Server (NTRS)

Sisk, Gregory A.

1989-01-01

The high-pressure oxidizer turbopump (HPOTP) consists of two centrifugal pumps, on a common shaft, that are directly driven by a hot-gas turbine. Pump shaft axial thrust is balanced in that the double-entry main inducer/impeller is inherently balanced and the thrusts of the preburner pump and turbine are nearly equal but opposite. Residual shaft thrust is controlled by a self-compensating, non-rubbing, balance piston. Shaft hang-up must be avoided if the balance piston is to perform properly. One potential cause of shaft hang-up is contact between the Phase 2 bearing support and axial spring cartridge of the HPOTP main pump housing. The status of the bearing support/axial spring cartridge interface is investigated under current loading conditions. An ANSYS version 4.3, three-dimensional, finite element model was generated on Lockheed's VAX 11/785 computer. A nonlinear thermal analysis was then executed on the Marshall Space Flight Center Engineering Analysis Data System (EADS). These thermal results were then applied along with the interference fit and bolt preloads to the model as load conditions for a static analysis to determine the gap status of the bearing support/axial spring cartridge interface. For possible further analysis of the local regions of HPOTP main pump housing assembly, detailed ANSYS submodels were generated using I-DEAS Geomod and Supertab (Appendix A).

Monitoring of bolted joints using piezoelectric active-sensing for aerospace applications

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

Park, Gyuhae; Farrar, Charles R; Park, Chan - Yik

2010-01-01

This paper is a report of an initial investigation into tracking and monitoring the integrity of bolted joints using piezoelectric active-sensors. The target application of this study is a fitting lug assembly of unmanned aerial vehicles (UAVs), where a composite wing is mounted to a UAV fuselage. The SHM methods deployed in this study are impedance-based SHM techniques, time-series analysis, and high-frequency response functions measured by piezoelectric active-sensors. Different types of simulated damage are introduced into the structure, and the capability of each technique is examined and compared. Additional considerations encountered in this initial investigation are made to guide furthermore » thorough research required for the successful field deployment of this technology.« less

Threaded average temperature thermocouple

NASA Technical Reports Server (NTRS)

Ward, Stanley W. (Inventor)

1990-01-01

A threaded average temperature thermocouple 11 is provided to measure the average temperature of a test situs of a test material 30. A ceramic insulator rod 15 with two parallel holes 17 and 18 through the length thereof is securely fitted in a cylinder 16, which is bored along the longitudinal axis of symmetry of threaded bolt 12. Threaded bolt 12 is composed of material having thermal properties similar to those of test material 30. Leads of a thermocouple wire 20 leading from a remotely situated temperature sensing device 35 are each fed through one of the holes 17 or 18, secured at head end 13 of ceramic insulator rod 15, and exit at tip end 14. Each lead of thermocouple wire 20 is bent into and secured in an opposite radial groove 25 in tip end 14 of threaded bolt 12. Resulting threaded average temperature thermocouple 11 is ready to be inserted into cylindrical receptacle 32. The tip end 14 of the threaded average temperature thermocouple 11 is in intimate contact with receptacle 32. A jam nut 36 secures the threaded average temperature thermocouple 11 to test material 30.

78 FR 21236 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-10

... Boeing Company Model 757 airplanes equipped with Rolls- Royce RB211-535E engines. That AD currently... attachment bolts of the aft hinge fittings of the thrust reversers. Request To Accomplish Certain Steps in the Service Information Out of Sequence AAL asked that it be allowed to accomplish certain steps in...

46 CFR 151.50-31 - Chlorine.

Code of Federal Regulations, 2010 CFR

2010-10-01

... inside diameter manhole, fitted with a cover located above the maximum liquid level and as close as... accessary equipment shall be of a type suitable for use with chlorine and shall be made of metal, corrosion... shutoff valves and with safety relief valves. All valves shall be bolted to the cover or covers specified...

77 FR 18137 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-27

...), latch pin migration, and broken latch pin fittings. This proposed AD would require various repetitive... cargo door latch mechanism and/or the lower sill structure. The migration of two or more latch pins and... determine if the bolt is broken; and checking the latch pin for migration and, if necessary, a detailed...

Stress analysis of bolted joints under centrifugal force

NASA Astrophysics Data System (ADS)

Imura, Makoto; Iizuka, Motonobu; Nakae, Shigeki; Mori, Takeshi; Koyama, Takayuki

2014-06-01

Our objective is to develop a long-life rotary machine for synchronous generators and motors. To do this, it is necessary to design a high-strength bolted joint, which is responsible for fixing a salient pole on a rotor shaft. While the rotary machine is in operation, not only centrifugal force but also moment are loaded on a bolted joint, because a point of load is eccentric to a centre of a bolt. We tried to apply the theory proposed in VDI2230-Blatt1 to evaluate the bolted joint under eccentric force, estimate limited centrifugal force, which is the cause of partial separation between the pole and the rotor shaft, and then evaluate additional tension of a bolt after the partial separation has occurred. We analyzed the bolted joint by FEM, and defined load introduction factor in that case. Additionally, we investigated the effect of the variation of bolt preload on the partial separation. We did a full scale experiment with a prototype rotor to reveal the variation of bolt preload against tightening torque. After that, we verified limited centrifugal force and the strength of the bolted joint by the VDI2230-Blatt1 theory and FEM considering the variation of bolt preload. Finally, we could design a high-strength bolted joint verified by the theoretical study and FEM analysis.

Failure Analysis on Tail Rotor Teeter Pivot Bolt on a Helicopter

NASA Astrophysics Data System (ADS)

Qiang, WANG; Zi-long, DONG

2018-03-01

Tail rotor teeter pivot bolt of a helicopter fractured when in one flight. Failure analysis on the bolt was finished in laboratory. Macroscopic observation of the tailor rotor teeter pivot bolt, macro and microscopic inspection on the fracture surface of the bolt was carried out. Chemical components and metallurgical structure was also carried out. Experiment results showed that fracture mode of the tail rotor teeter pivot bolt is fatigue fracture. Fatigue area is over 80% of the total fracture surface, obvious fatigue band characteristics can be found at the fracture face. According to the results were analyzed from the macroscopic and microcosmic aspects, fracture reasons of the tail rotor teeter pivot bolt were analyzed in detail

Bolted Double-Lap Composite Joints Under Mechanical and Thermal Loading

NASA Technical Reports Server (NTRS)

Kradinov, V.; Barut, A.; Madenci, E.; Walker, Sandra P. (Technical Monitor)

2000-01-01

This study concerns the determination of the contact stresses and contact region around bolt holes and the bolt load distribution in single- and double-lap joints of composite laminates with arbitrarily located bolts under general mechanical loading conditions and uniform temperature change. The unknown contact stress distribution and contact region between the bolt and laminates and the interaction among the bolts require the bolt load distribution, as well as the contact stresses, to be as part of the solution. The present method is based on the complex potential theory and the variational formulation in order to account for bolt stiffness, bolt-hole clearance, and finite geometry of the composite laminates.

Parametric Study of Single Bolted Composite Bolted Joint Subjected to Static Tensile Loading

NASA Astrophysics Data System (ADS)

Awadhani, L. V.; Bewoor, Anand, Dr.

2017-08-01

The use of composites is increasing in the engineering applications in order to reduce the weight, building energy efficient systems, designing a suitable material according to the requirements of the application. But at the same time, building a structure is possible only by bonding or bolting or combination of them. There are limitations for the bonding methods and problems with the bolting such as stress concentration near the neighborhood of the bolt hole, tensile or shear failure, delamination etc. Hence the design of a composite bolted structure needs a special attention. This paper focuses on the performance of the composite bolted joint under static tensile loading and the effect of variation in the parameters such as the bolt pitch, plate width, thickness, bolt tightening torque, composite material, coefficient of friction between the bolt and plate etc. A simple spring mass model is used to study the single bolted composite bolted joint. The influencing parameters are identified through the developed model and compared with the results from the literature. The best geometric parameters for the applied load are identified for the composite bolted joints.

Sectional device handling tool

DOEpatents

Candee, Clark B.

1988-07-12

Apparatus for remotely handling a device in an irradiated underwater environment includes a plurality of tubular sections interconnected end-to-end to form a handling structure, the bottom section being adapted for connection to the device. A support section is connected to the top tubular section and is adapted to be suspended from an overhead crane. Each section is flanged at its opposite ends. Axially retractable bolts in each bottom flange are threadedly engageable with holes in the top flange of an adjacent section, each bolt being biased to its retracted position and retained in place on the bottom flange. Guide pins on each top flange cooperate with mating holes on adjacent bottom flanges to guide movement of the parts to the proper interconnection orientation. Each section carries two hydraulic line segments provided with quick-connect/disconnect fittings at their opposite ends for connection to the segments of adjacent tubular sections upon interconnection thereof to form control lines which are connectable to the device and to an associated control console.

Contact acoustic nonlinearity (CAN)-based continuous monitoring of bolt loosening: Hybrid use of high-order harmonics and spectral sidebands

NASA Astrophysics Data System (ADS)

Zhang, Zhen; Liu, Menglong; Liao, Yaozhong; Su, Zhongqing; Xiao, Yi

2018-03-01

The significance of evaluating bolt tightness in engineering structures, preferably in a continuous manner, cannot be overemphasized. With hybrid use of high-order harmonics (HOH) and spectral sidebands, a contact acoustic nonlinearity (CAN)-based monitoring framework is developed for detecting bolt loosening and subsequently evaluating the residual torque on a loose bolt. Low-frequency pumping vibration is introduced into the bolted joint to produce a "breathing" effect at the joining interface that modulates the propagation characteristics of a high-frequency probing wave when it traverses the bolt, leading to the generation of HOH and vibro-acoustic nonlinear distortions (manifested as sidebands in the signal spectrum). To gain insight into the mechanism of CAN generation and to correlate the acquired nonlinear responses of a loose joint with the residual torque remaining on the bolt, an analytical model based on micro-contact theory is established. Two types of nonlinear index, respectively exploiting the induced HOH and spectral sidebands, are defined without dependence on excitation intensity and are experimentally demonstrated to be effective in continuously monitoring bolt loosening in both aluminum-aluminum and composite-composite bolted joints. Taking a step further, variation of the index pair is quantitatively associated with the residual torque on a loose bolt. The approach developed provides a reliable method of continuous evaluation of bolt tightness in both composite and metallic joints, regardless of their working conditions, from early awareness of bolt loosening at an embryonic stage to quantitative estimation of residual torque.

Behavior of Fiber Glass Bolts, Rock Bolts and Cable Bolts in Shear

NASA Astrophysics Data System (ADS)

Li, Xuwei; Aziz, Naj; Mirzaghorbanali, Ali; Nemcik, Jan

2016-07-01

This paper experimentally compares the shear behavior of fiber glass (FG) bolt, rock bolt (steel rebar bolt) and cable bolt for the bolt contribution to bolted concrete surface shear strength, and bolt failure mode. Two double shear apparatuses of different size were used for the study. The tensile strength, the shear strength and the deformation modulus of bolt control the shear behavior of a sheared bolted joint. Since the strength and deformation modulus of FG bolt, rock bolt and cable bolt obtained from uniaxial tensile tests are different, their shear behavior in reinforcing joints is accordingly different. Test results showed that the shear stiffness of FG bolted joints decreased gradually from the beginning to end, while the shear stiffness of joints reinforced by rock bolt and cable bolt decreased bi-linearly, which is clearly consistent with their tensile deformation modulus. The bolted joint shear stiffness was highly influenced by bolt pretension in the high stiffness stage for both rock bolt and cable bolt, but not in the low stiffness stage. The rock bolt contribution to joint shear strength standardised by the bolt tensile strength was the largest, followed by cable bolts, then FG bolts. Both the rock bolts and cable bolts tended to fail in tension, while FG bolts in shear due to their low shear strength and constant deformation modulus.

Monitoring of Pre-Load on Rock Bolt Using Piezoceramic-Transducer Enabled Time Reversal Method.

PubMed

Huo, Linsheng; Wang, Bo; Chen, Dongdong; Song, Gangbing

2017-10-27

Rock bolts ensure structural stability for tunnels and many other underground structures. The pre-load on a rock bolt plays an important role in the structural reinforcement and it is vital to monitor the pre-load status of rock bolts. In this paper, a rock bolt pre-load monitoring method based on the piezoceramic enabled time reversal method is proposed. A lead zirconate titanate (PZT) patch transducer, which works as an actuator to generate stress waves, is bonded onto the anchor plate of the rock bolt. A smart washer, which is fabricated by sandwiching a PZT patch between two metal rings, is installed between the hex nut and the anchor plate along the rock bolt. The smart washer functions as a sensor to detect the stress wave. With the increase of the pre-load values on the rock bolt, the effective contact surface area between the smart washer and the anchor plate, benefiting the stress wave propagation crossing the contact surface. With the help of time reversal technique, experimental results reveal that the magnitude of focused signal clearly increases with the increase of the pre-load on a rock bolt before the saturation which happens beyond a relatively high value of the pre-load. The proposed method provides an innovative and real time means to monitor the pre-load level of a rock bolt. By employing this method, the pre-load degradation process on a rock bolt can be clearly monitored. Please note that, currently, the proposed method applies to only new rock bolts, on which it is possible to install the PZT smart washer.

Measuring mine roof bolt strains

DOEpatents

Steblay, Bernard J.

1986-01-01

A mine roof bolt and a method of measuring the strain in mine roof bolts of this type are disclosed. According to the method, a flat portion on the head of the mine roof bolt is first machined. Next, a hole is drilled radially through the bolt at a predetermined distance from the bolt head. After installation of the mine roof bolt and loading, the strain of the mine roof bolt is measured by generating an ultrasonic pulse at the flat portion. The time of travel of the ultrasonic pulse reflected from the hole is measured. This time of travel is a function of the distance from the flat portion to the hole and increases as the bolt is loaded. Consequently, the time measurement is correlated to the strain in the bolt. Compensation for various factors affecting the travel time are also provided.

A new design concept of fully grouted rock bolts in underground construction

NASA Astrophysics Data System (ADS)

Phich Nguyen, Quang; Nguyen, Van Manh; Tuong Nguyen, Ke

2018-04-01

The main problem after excavating an underground excavation is to maintain the stability of the excavation for a certain period of time. Failure in meeting this demand is a threat to safety of men and equipment. Support and reinforcement are different instruments with different mechanisms. Among the common support systems in tunnelling and mining, rock bolts have been widely used to reinforce rock mass and also to reduce geological hazards. Furthermore rock bolts can be applied under varying different geological conditions with cost-effectiveness. Although different methods are developed for grouted rock bolts design until now, the interaction mechanism of the rock bolts and rock mass is still very complicated issue. The paper addresses an analytical model for the analysis and design of fully grouted rock bolts based on the reinforcement principle. According to this concept the jointed rock mass reinforced by grouted rock bolts is considered as composite material which includes rock mass, the grout material and the bolt shank. The mechanical properties of this composite material depend on the ratio of the components. The closed-form solution was developed based on the assumption that the rock mass arround a circular tunnel remained elastic after installing fully grouted rock bolts. The main parameters of the rock-bolt system (the diameter and length of bolt shank, the space between the bolts) are then easily estimated from the obtained solution.

Study on the Optimal Groove Shape and Glue Material for Fiber Bragg Grating Measuring Bolts.

PubMed

Zhao, Yiming; Zhang, Nong; Si, Guangyao; Li, Xuehua

2018-06-02

Fiber Bragg grating (FBG) measuring bolts, as a useful tool to evaluate the behaviors of steel bolts in underground engineering, can be manufactured by gluing the FBG sensors inside the grooves, which are usually symmetrical cuts along the steel bolt rod. The selection of the cut shape and the glue types could perceivably affect the final supporting strength of the bolts. Unfortunately, the impact of cut shape and glue type on bolting strength is not yet clear. In this study, based on direct tension tests, full tensile load⁻displacement curves of rock bolts with different groove shapes were obtained and analyzed. The effects of groove shape on the bolt strength were discussed, and the stress redistribution in the cross-section of a rock bolt with different grooves was simulated using ANSYS. The results indicated that the trapezoidal groove is best for manufacturing the FBG bolt due to its low reduction of supporting strength. Four types of glues commonly used for the FBG sensors were assessed by conducting tensile tests on the mechanical testing and simulation system and the static and dynamic optical interrogators system. Using linear regression analysis, the relationship between the reflected wavelength of FBG sensors and tensile load was obtained. Practical recommendations for glue selection in engineering practice are also provided.

High speed door assembly

DOEpatents

Shapiro, Carolyn

1993-01-01

A high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

33. Three bolts on railing outside control house on north ...

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

33. Three bolts on railing outside control house on north tower, one bolt on first handrail post of the north span (bridge is in the open position). As the bridge opens or closes the single bolt on the handrail post moves past the three stationary bolts. This system is used by the bridge operator to judge speed and position of the north span as it opens or closes. Based on these bolts movement of the north span is speeded up or slowed down and the brakes applied during the opening and closing process. View facing east. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

46 CFR 56.25-20 - Bolting.

Code of Federal Regulations, 2010 CFR

2010-10-01

... chapter for exceptions on bolting used in fluid power and control systems. (b) Carbon steel bolts or bolt... less than that at the root of the threads. They must have heavy semifinished hexagonal nuts in...

Analytical Study of the Mechanical Behavior of Fully Grouted Bolts in Bedding Rock Slopes

NASA Astrophysics Data System (ADS)

Liu, C. H.; Li, Y. Z.

2017-09-01

Bolting is widely used as a reinforcement means for rock slopes. The support force of a fully grouted bolt is often provided by the combination of the axial and shear forces acting at the cross section of the bolt, especially for bedding rock slopes. In this paper, load distribution and deformation behavior of the deflecting section of a fully grouted bolt were analyzed, and a structural mechanical model was established. Based on force method equations and deformation compatibility relationships, an analytical approach, describing the contribution of the axial and shear forces acting at the intersection between the bolt and the joint plane to the stability of a rock slope, was developed. Influence of the inclination of the bolt to the joint plane was discussed. Laboratory tests were conducted with different inclinations of the bolt to the joint plane. Comparisons between the proposed approach, the experimental data and a code method were made. The calculation results are in good agreement with the test data. It is shown that transverse shear resistance plays a significant role to the bolting contribution and that the bigger the dip of the bolt to the joint plane, the more significant the dowel effect. It is also shown that the design method suggested in the code overestimates the resistance of the bolt. The proposed model considering dowel effect provides a more precise description on bolting properties of bedding rock slopes than the code method and will be helpful to improve bolting design methods.

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.

A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring.

PubMed

Wu, Jian; Cui, Xingmei; Xu, Yunpeng

2016-01-28

In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag's antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt's information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system.

The effect of cultivar, sowing date and transplant location in field on bolting of Welsh onion (Allium fistulosum L.)

PubMed Central

2013-01-01

Background Bolting reduces the quality and commercial yield of Welsh onion (Allium fistulosum L.) in production. However, seed production is directly dependent on flower induction and bolting. The Welsh onion belongs to the green plant vernalisation type, specific seedling characteristics and sufficient accumulated time at low temperature are indispensible for the completion of its vernalisation process. Only if these conditions for vernalisation are fulfilled, the plants will bolt in the following year. The present investigation evaluated the effects of cultivar, sowing date and transplant location in field on the bolting of Welsh onion at the Horticultural Farm of the College of Horticulture, Northwest A&F University, Yangling, Shannxi Province, China in two succeeding production years: 2010–2011 and 2011–2012. A strip split plot layout within a randomised complete block design with three replications was used. Results The results revealed that all three factors (cultivar, sowing date and transplant location) and their interaction had significant effects on the initiation and final rate of bolting observed by 30 April. The earliest bolting date (14 February, 2011 and 15 February, 2012) and the highest bolting rate (100% in 2011 and 62% in 2012) occurred when the JinGuan cultivar was sown on 20 August and transplanted in a plastic tunnel, whereas the latest date and lowest rate (no bolting observed until 30 April) of bolting occurred when the XiaHei cultivar was sown on 29 September and transplanted in an open field. Conclusions These results suggest that we can control bolting in Welsh onion production by choosing an appropriate cultivar, sowing date and transplant location. Choosing a late bolting cultivar, such as cultivar XiaHei, sowing around October, and transplanting in the open field can significantly delay bolting, while a sowing date in late August should be selected for seed production, and the seedlings should be transplanted in a plastic tunnel to accelerate development of the flower buds. PMID:24199907

The effect of cultivar, sowing date and transplant location in field on bolting of Welsh onion (Allium fistulosum L.).

PubMed

Dong, Yinxin; Cheng, Zhihui; Meng, Huanwen; Liu, Hanqiang; Wu, Cuinan; Khan, Abdul Rehman

2013-10-07

Bolting reduces the quality and commercial yield of Welsh onion (Allium fistulosum L.) in production. However, seed production is directly dependent on flower induction and bolting. The Welsh onion belongs to the green plant vernalisation type, specific seedling characteristics and sufficient accumulated time at low temperature are indispensible for the completion of its vernalisation process. Only if these conditions for vernalisation are fulfilled, the plants will bolt in the following year. The present investigation evaluated the effects of cultivar, sowing date and transplant location in field on the bolting of Welsh onion at the Horticultural Farm of the College of Horticulture, Northwest A&F University, Yangling, Shannxi Province, China in two succeeding production years: 2010-2011 and 2011-2012. A strip split plot layout within a randomised complete block design with three replications was used. The results revealed that all three factors (cultivar, sowing date and transplant location) and their interaction had significant effects on the initiation and final rate of bolting observed by 30 April. The earliest bolting date (14 February, 2011 and 15 February, 2012) and the highest bolting rate (100% in 2011 and 62% in 2012) occurred when the JinGuan cultivar was sown on 20 August and transplanted in a plastic tunnel, whereas the latest date and lowest rate (no bolting observed until 30 April) of bolting occurred when the XiaHei cultivar was sown on 29 September and transplanted in an open field. These results suggest that we can control bolting in Welsh onion production by choosing an appropriate cultivar, sowing date and transplant location. Choosing a late bolting cultivar, such as cultivar XiaHei, sowing around October, and transplanting in the open field can significantly delay bolting, while a sowing date in late August should be selected for seed production, and the seedlings should be transplanted in a plastic tunnel to accelerate development of the flower buds.

Analysis on Sealing Reliability of Bolted Joint Ball Head Component of Satellite Propulsion System

NASA Astrophysics Data System (ADS)

Guo, Tao; Fan, Yougao; Gao, Feng; Gu, Shixin; Wang, Wei

2018-01-01

Propulsion system is one of the important subsystems of satellite, and its performance directly affects the service life, attitude control and reliability of the satellite. The Paper analyzes the sealing principle of bolted joint ball head component of satellite propulsion system and discuss from the compatibility of hydrazine anhydrous and bolted joint ball head component, influence of ground environment on the sealing performance of bolted joint ball heads, and material failure caused by environment, showing that the sealing reliability of bolted joint ball head component is good and the influence of above three aspects on sealing of bolted joint ball head component can be ignored.

A Review of Rock Bolt Monitoring Using Smart Sensors.

PubMed

Song, Gangbing; Li, Weijie; Wang, Bo; Ho, Siu Chun Michael

2017-04-05

Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This work presents a brief introduction on the types of rock bolts followed by a comprehensive review of rock bolt monitoring using smart sensors. Smart sensors that are used to assess rock bolt integrity are reviewed to provide a firm perception of the application of smart sensors for enhanced performance and reliability of rock bolts. The most widely used smart sensors for rock bolt monitoring are the piezoelectric sensors and the fiber optic sensors. The methodologies and principles of these smart sensors are reviewed from the point of view of rock bolt integrity monitoring. The applications of smart sensors in monitoring the critical status of rock bolts, such as the axial force, corrosion occurrence, grout quality and resin delamination, are highlighted. In addition, several prototypes or commercially available smart rock bolt devices are also introduced.

A Review of Rock Bolt Monitoring Using Smart Sensors

PubMed Central

Song, Gangbing; Li, Weijie; Wang, Bo; Ho, Siu Chun Michael

2017-01-01

Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This work presents a brief introduction on the types of rock bolts followed by a comprehensive review of rock bolt monitoring using smart sensors. Smart sensors that are used to assess rock bolt integrity are reviewed to provide a firm perception of the application of smart sensors for enhanced performance and reliability of rock bolts. The most widely used smart sensors for rock bolt monitoring are the piezoelectric sensors and the fiber optic sensors. The methodologies and principles of these smart sensors are reviewed from the point of view of rock bolt integrity monitoring. The applications of smart sensors in monitoring the critical status of rock bolts, such as the axial force, corrosion occurrence, grout quality and resin delamination, are highlighted. In addition, several prototypes or commercially available smart rock bolt devices are also introduced. PMID:28379167

Behaviour of steel-concrete composite beams using bolts as shear connectors

NASA Astrophysics Data System (ADS)

Tran, Minh-Tung; Nguyen Van Do, Vuong; Nguyen, Tuan-Anh

2018-04-01

The paper presents an experimental program on the application of bolts as shear connectors for steel-composite beams. Four steel- concrete composite beams and a reference steel beam were made and tested. The aim of the testing program is to examine which forms of the steel bolts can be used effectively for steel-composite beams. The four types of the bolts include: Type 1 the bolt with the nut at the end; Type 2 the bolt bending at 900 hook; Type 3 the bolt without the nut at the end and Type 4 the bolt with the nut at the end but connected with the steel beam by hand welding in other to be connected with the steel beam by bolt connection as in the first three types. The test results showed that beside the traditional shear connectors like shear studs, angle type, channel type, bolts can be used effectively as the shear connectors in steel-composite beams and the application of bolts in Types 1 and 2 in the composite beams gave the better performance for the tested beam.

Conceptual Design Study on Bolts for Self-Loosing Preventable Threaded Fasteners

NASA Astrophysics Data System (ADS)

Noma, Atsushi; He, Jianmei

2017-11-01

Threaded fasteners using bolts is widely applied in industrial field as well as various fields. However, threaded fasteners using bolts have loosing problems and cause many accidents. In this study, the purpose is to obtain self-loosing preventable threaded fasteners by applying spring characteristic effects on bolt structures. Helical-cutting applied bolt structures is introduced through three dimensional (3D) CAD modeling tools. Analytical approaches for evaluations on the spring characteristic effects helical-cutting applied bolt structures and self-loosing preventable performance of threaded fasteners were performed using finite element method and results are reported. Comparing slackness test results with analytical results and more details on evaluating mechanical properties will be executed in future study.

Transcriptomic analysis reveals the roles of gibberellin-regulated genes and transcription factors in regulating bolting in lettuce (Lactuca sativa L.).

PubMed

Liu, Xueying; Lv, Shanshan; Liu, Ran; Fan, Shuangxi; Liu, Chaojie; Liu, Renyi; Han, Yingyan

2018-01-01

A cool temperature is preferred for lettuce cultivation, as high temperatures cause premature bolting. Accordingly, exploring the mechanism of bolting and preventing premature bolting is important for agriculture. To explore this relationship in depth, morphological, physiological, and transcriptomic analyses of the bolting-sensitive line S39 at the five-leaf stage grown at 37°C were performed in the present study. Based on paraffin section results, we observed that S39 began bolting on the seventh day at 37°C. During bolting in the heat-treated plants, GA3 and GA4 levels in leaves and the indoleacetic acid (IAA) level in the stem reached a maximum on the sixth day, and these high contents were maintained. Additionally, bolting begins in the fifth day after GA3 treatment in S39 plants, GA3 and GA4 increased and then decreased, reaching a maximum on the fourth day in leaves. Similarly, IAA contents reached a maximum in the stem on the fifth day. No bolting was observed in the control group grown at 25°C, and significant changes were not observed in GA3 and GA4 levels in the controls during the observation period. RNA-sequencing data implicated transcription factors (TFs) in regulating bolting in lettuce, suggesting that the high GA contents in the leaves and IAA in the stem promote bolting. TFs possibly modulate the expression of related genes, such as those encoding hormones, potentially regulating bolting in lettuce. Compared to the control group, 258 TFs were identified in the stem of the treatment group, among which 98 and 156 were differentially up- and down-regulated, respectively; in leaves, 202 and 115 TFs were differentially up- and down-regulated, respectively. Significant changes in the treated group were observed for C2H2 zinc finger, AP2-EREBP, and WRKY families, indicating that these TFs may play important roles in regulating bolting.

Effect of fiberglass reinforcement on the behavior of bolted wood connections

Treesearch

Lawrence A. Soltis; Robert J. Ross; Daniel E. Windorski

1997-01-01

Bolted connections often fail by a shear plug or by splitting beneath the bolt caused by tension perpendicular-to-grain stress as the bolt wedges its way through the wood. Preventing this type of failure enhances both the capacity and reliability of bolted connections. This research investigated the use of fiberglass reinforcement to enhance the load-carrying capacity...

High-strength bolt corrosion fatigue life model and application.

PubMed

Hui-li, Wang; Si-feng, Qin

2014-01-01

The corrosion fatigue performance of high-strength bolt was studied. Based on the fracture mechanics theory and the Gerberich-Chen formula, the high-strength bolt corrosion fracture crack model and the fatigue life model were established. The high-strength bolt crack depth and the fatigue life under corrosion environment were quantitatively analyzed. The factors affecting high-strength bolt corrosion fatigue life were discussed. The result showed that the high-strength bolt corrosion fracture biggest crack depth reduces along with the material yield strength and the applied stress increases. The material yield strength was the major factor. And the high-strength bolt corrosion fatigue life reduced along with the increase of material strength, the applied stress or stress amplitude. The stress amplitude influenced the most, and the material yield strength influenced the least. Low bolt strength and a low stress amplitude level could extend high-strength bolt corrosion fatigue life.

A New Tool for Industry

NASA Technical Reports Server (NTRS)

1981-01-01

Ultrasonic P2L2 bolt monitor is a new industrial tool, developed at Langley Research Laboratory, which is lightweight, portable, extremely accurate because it is not subject to friction error, and it is cost-competitive with the least expensive of other types of accurate strain monitors. P2L2 is an acronym for Pulse Phase Locked Loop. The ultrasound system which measures the stress that occurs when a bolt becomes elongated in the process of tightening, transmits sound waves to the bolt being fastened and receives a return signal indicating changes in bolt stress. Results are translated into a digital reading of the actual stress on the bolt. Device monitors the bolt tensioning process on mine roof bolts that provide increased safety within the mine. Also has utility in industrial applications.

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

PubMed

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

2018-06-13

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

Discussion on Influence of High Strength Bolt’s Parameters on the Weld Reinforced Combined Connection with Bolts and Welds

NASA Astrophysics Data System (ADS)

Ma, Jiansuo; Wang, Yuanqing; Li, Mingfeng; Bai, Runshan; Ban, Huiyong

2018-03-01

In the process of existing steel structure operation, in order to prevent the bolted joints from being damaged by insufficient carrying capacity, welds can be used for reinforcement. Weld reinforced combined connection with bolts and weld consists with high strength bolts and side fillet weld composition. The parameters and properties of high strength bolts and fillet welds have a direct effect on the connection. Based on the test results, We explore the influence that welding seam reinforcement and the performance of the connection between the number of high strength bolts and specifications changes in this paper. It will provide a theoretical reference for the design of connection nodes of steel structure reinforcement project.

High speed door assembly

DOEpatents

Shapiro, C.

1993-04-27

A high speed door assembly is described, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

75 FR 46873 - Airworthiness Directives; Airbus Model A318-111 and A318-112 Airplanes and Model A319, A320, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-04

... fittings of the 80VU rack, typically elongated holes, migrated bushes [bushings], and/or missing bolts have... with a high load factor or strong vibration could lead to failure of the rack structure and/or... rack contains computers for Flight Controls, Communication and Radio-navigation. These functions are...

Fastener stretcher

NASA Technical Reports Server (NTRS)

Oconnor, J. W.; Orem, V. C. (Inventor)

1973-01-01

A description is given of a fastener stretcher used to apply a substantial pure axial tensile force to a structural bolt or similar fastening element. The system is comprised of a pair of telescoping elements, one of which is temporarily secured to the bolt. By spreading the telescoping elements axially, the bolt is tensioned axially to permit a nut or the like to be threaded with a minimum of torque; when the elements are then removed from the bolt, the axial forces on the bolt are taken up by the nut to retain the bolt in its stressed state.

78 FR 33855 - Merchant Mariner Medical Advisory Committee: Intercessional Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... Medical Evaluation Report and CG-719K/E, Merchant Mariner Evaluation of Fitness for Entry Level Ratings..., Merchant Mariner Evaluation of Fitness for Entry Level Ratings. (4) Closing remarks. Day 2 The agenda for...

A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring

PubMed Central

Wu, Jian; Cui, Xingmei; Xu, Yunpeng

2016-01-01

In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag’s antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt’s information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. PMID:26828498

Bolt Stress Monitor

NASA Technical Reports Server (NTRS)

1978-01-01

In photo, an engineer is using a new Ultrasonic Bolt Stress Monitor developed by NASA's Langley Research Center to determine whether a bolt is properly tightened. A highly accurate device, the monitor is an important tool in construction of such structures as pressure vessels, bridges and power plants, wherein precise measurement of the stress on a tightened bolt is critical. Overtightened or undertightened bolts can fail and cause serious industrial accidents or costly equipment break-downs. There are a number of methods for measuring bolt stress. Most widely used and least costly is the torque wrench, which is inherently inaccurate; it does not take into account the friction between nut and bolt, which has an influence on stress. At the other end of the spectrum, there are accurate stress-measuring systems, but they are expensive and not portable. The battery-powered Langley monitor fills a need; it is inexpensive, lightweight, portable and extremely accurate because it is not subject to friction error. Sound waves are transmitted to the bolt and a return signal is received. As the bolt is tightened, it undergoes changes in resonance due to stress, in the manner that a violin string changes tone when it is tightened. The monitor measures the changes in resonance and provides a reading of real stress on the bolt. The device, patented by NASA, has aroused wide interest and a number of firms have applied for licenses to produce it for the commercial market.

Combined In-Plane and Through-the-Thickness Analysis for Failure Prediction of Bolted Composite Joints

NASA Technical Reports Server (NTRS)

Kradinov, V.; Madenci, E.; Ambur, D. R.

2004-01-01

Although two-dimensional methods provide accurate predictions of contact stresses and bolt load distribution in bolted composite joints with multiple bolts, they fail to capture the effect of thickness on the strength prediction. Typically, the plies close to the interface of laminates are expected to be the most highly loaded, due to bolt deformation, and they are usually the first to fail. This study presents an analysis method to account for the variation of stresses in the thickness direction by augmenting a two-dimensional analysis with a one-dimensional through the thickness analysis. The two-dimensional in-plane solution method based on the combined complex potential and variational formulation satisfies the equilibrium equations exactly, and satisfies the boundary conditions and constraints by minimizing the total potential. Under general loading conditions, this method addresses multiple bolt configurations without requiring symmetry conditions while accounting for the contact phenomenon and the interaction among the bolts explicitly. The through-the-thickness analysis is based on the model utilizing a beam on an elastic foundation. The bolt, represented as a short beam while accounting for bending and shear deformations, rests on springs, where the spring coefficients represent the resistance of the composite laminate to bolt deformation. The combined in-plane and through-the-thickness analysis produces the bolt/hole displacement in the thickness direction, as well as the stress state in each ply. The initial ply failure predicted by applying the average stress criterion is followed by a simple progressive failure. Application of the model is demonstrated by considering single- and double-lap joints of metal plates bolted to composite laminates.

Impedance-Based Pre-Stress Monitoring of Rock Bolts Using a Piezoceramic-Based Smart Washer-A Feasibility Study.

PubMed

Wang, Bo; Huo, Linsheng; Chen, Dongdong; Li, Weijie; Song, Gangbing

2017-01-27

Pre-stress degradation or looseness of rock bolts in mining or tunnel engineering threatens the stability and reliability of the structures. In this paper, an innovative piezoelectric device named a "smart washer" with the impedance method is proposed with the aim of developing a real-time device to monitor the pre-stress level of rock bolts. The proposed method was verified through tests on a rock bolt specimen. By applying high-frequency sweep excitations (typically >30 kHz) to the smart washer that was installed on the rock bolt specimen, we observed that the variation in impedance signatures indicated the rock bolt pre-stress status. With the degradation of rock bolt pre-stress, the frequency in the dominating peak of the real part of the electrical impedance signature increased. To quantify the effectiveness of the proposed technique, a normalized root mean square deviation (RMSD) index was developed to evaluate the degradation level of the rock bolt pre-stress. The experimental results demonstrated that the normalized RMSD-based looseness index, which was computed from the impedance value detected by the "smart washer", increased with loss of the pre-stress of the rock bolt. Therefore, the proposed method can effectively detect the degradation of rock bolt pre-stress, as demonstrated by experiments.

Image Registration-Based Bolt Loosening Detection of Steel Joints

PubMed Central

2018-01-01

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

Image Registration-Based Bolt Loosening Detection of Steel Joints.

PubMed

Kong, Xiangxiong; Li, Jian

2018-03-28

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

Impedance-Based Pre-Stress Monitoring of Rock Bolts Using a Piezoceramic-Based Smart Washer—A Feasibility Study

PubMed Central

Wang, Bo; Huo, Linsheng; Chen, Dongdong; Li, Weijie; Song, Gangbing

2017-01-01

Pre-stress degradation or looseness of rock bolts in mining or tunnel engineering threatens the stability and reliability of the structures. In this paper, an innovative piezoelectric device named a “smart washer” with the impedance method is proposed with the aim of developing a real-time device to monitor the pre-stress level of rock bolts. The proposed method was verified through tests on a rock bolt specimen. By applying high-frequency sweep excitations (typically >30 kHz) to the smart washer that was installed on the rock bolt specimen, we observed that the variation in impedance signatures indicated the rock bolt pre-stress status. With the degradation of rock bolt pre-stress, the frequency in the dominating peak of the real part of the electrical impedance signature increased. To quantify the effectiveness of the proposed technique, a normalized root mean square deviation (RMSD) index was developed to evaluate the degradation level of the rock bolt pre-stress. The experimental results demonstrated that the normalized RMSD-based looseness index, which was computed from the impedance value detected by the “smart washer”, increased with loss of the pre-stress of the rock bolt. Therefore, the proposed method can effectively detect the degradation of rock bolt pre-stress, as demonstrated by experiments. PMID:28134811

Ball-and-Socket Joint Can Be Disassembled

NASA Technical Reports Server (NTRS)

Totah, R. S.

1982-01-01

Ball-and-socket joint originally developed for construction of large platforms in zero g could be used in such Earth-based temporary structures as scaffolding, camping equipment, tent posts, trade shows and displays. New joint consists of a socket mounted on central hub or union and ball-ended bolt or fitting mounted at end of a column or any structural member. Unit is self-contained, requires no loose hardware and is engaged or disengaged without tools manually, or remotely by a manipulator.

Fixture For Drilling And Tapping A Curved Workpiece

NASA Technical Reports Server (NTRS)

Espinosa, P. S.; Lockyer, R. T.

1992-01-01

Simple fixture guides drilling and tapping of holes in prescribed locations and orientations on workpiece having curved surface. Tool conceived for use in reworking complexly curved helicopter blades made of composite materials. Fixture is block of rigid foam with epoxy filler, custom-fitted to surface contour, containing bushings and sleeves at drilling and tapping sites. Bushings changed, so taps and drills of various sizes accommodated. In use, fixture secured to surface by hold-down bolts extending through sleeves and into threads in substrate.

Experimental study on the effect of shape of bolt and nut on fatigue strength for bolted joint

NASA Astrophysics Data System (ADS)

Matsunari, T.; Oda, K.; Tsutsumi, N.; Yakushiji, T.; Noda, N. A.; Sano, Y.

2018-06-01

In this study, the effect of curvature radius of the thread bottom and the pitch difference between of M16 bolt and nut on fatigue strength for bolted joint is considered experimentally. The M16 bolt-nut specimens having the two kinds of thread bottom radii and the pitch differences are prepared. The S-N curves for bolted specimens with different thread shapes are obtained by the stress-controlled fatigue test (stress ratio R>0). The experimental results are compared and discussed in terms of stress analysis. The finite element method is used to make a simulation of the fatigue experiment and the mean stress and stress amplitude at each thread bottom of bolt are analysed. It is found that the initiation and propagation of crack are changed by introducing the pitch difference of α=15 μm from the crack observation in cross section of the bolt specimens after the experiment. Furthermore, the fatigue life can be extended by increasing curvature radius of thread bottom and introducing the pitch difference.

Flexible roof drill for low coal. Volume 2. Phase III and Phase IV

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

Shoup, N.H.

1977-09-01

Design specifications were developed for a flexible drilling and bolting system. The system configuration is based on the use of the Galis dual-boom roof drill as a vehicle for the drilling/bolting system. The WSU Flex-drill drivehead is mounted on the Galis drill boom and the Galis parts are modified to accommodate the revised system. The flexible drillhead supports a bolt bender/inserter designed by Bendix Corporation and is integrated into the system operation. A supplemental bolt thruster was designed to complete insertion of the roof bolt following operation and removal of the Bendix bender from the bolt shank. The complete cyclemore » of drilling a 1-3/8-in. diameter bolt hole, bending a roof bolt into the hole, thrusting the bolt head and washer to the roof surface, and final torquing of the bolt is manually controlled by the operator located in the new position behind the bolting line. The new operating position is beneath newly bolted roof in a safer location in back of the stab jack ad roof jacks positioning the drill boom and drivehead. The Flex-drill/bolting system prototype was constructed from both purchased components and parts specially fabricated in the shops for this design. This unit was assembled and test-operated with appropriate support equipment in a laboratory test stand. Numerous test holes were drilled in blocks of concrete at feed rates of 5 ft/min with drill rotation speeds of 360 rpm. The drill feeds uniformly and cuts smoothly with no difficulty in collection of dust or clogging of the drill bit. The holes drilled were straight, as evidence by passage of a 1-1/4-in. diameter bar full depth into the hole with no binding or evidence of curvature. The flexible drill is capable of drilling 8-ft-deep roof bolt holes in low coal 36 in. in height.« less

Non-destructive testing of full-length bonded rock bolts based on HHT signal analysis

NASA Astrophysics Data System (ADS)

Shi, Z. M.; Liu, L.; Peng, M.; Liu, C. C.; Tao, F. J.; Liu, C. S.

2018-04-01

Full-length bonded rock bolts are commonly used in mining, tunneling and slope engineering because of their simple design and resistance to corrosion. However, the length of a rock bolt and grouting quality do not often meet the required design standards in practice because of the concealment and complexity of bolt construction. Non-destructive testing is preferred when testing a rock bolt's quality because of the convenience, low cost and wide detection range. In this paper, a signal analysis method for the non-destructive sound wave testing of full-length bonded rock bolts is presented, which is based on the Hilbert-Huang transform (HHT). First, we introduce the HHT analysis method to calculate the bolt length and identify defect locations based on sound wave reflection test signals, which includes decomposing the test signal via empirical mode decomposition (EMD), selecting the intrinsic mode functions (IMF) using the Pearson Correlation Index (PCI) and calculating the instantaneous phase and frequency via the Hilbert transform (HT). Second, six model tests are conducted using different grouting defects and bolt protruding lengths to verify the effectiveness of the HHT analysis method. Lastly, the influence of the bolt protruding length on the test signal, identification of multiple reflections from defects, bolt end and protruding end, and mode mixing from EMD are discussed. The HHT analysis method can identify the bolt length and grouting defect locations from signals that contain noise at multiple reflected interfaces. The reflection from the long protruding end creates an irregular test signal with many frequency peaks on the spectrum. The reflections from defects barely change the original signal because they are low energy, which cannot be adequately resolved using existing methods. The HHT analysis method can identify reflections from the long protruding end of the bolt and multiple reflections from grouting defects based on mutations in the instantaneous frequency, which makes weak reflections more noticeable. The mode mixing phenomenon is observed in several tests, but this does not markedly affect the identification results due to the simple medium in bolt tests. The mode mixing can be reduced by ensemble EMD (EEMD) or complete ensemble EMD with adaptive noise (CEEMDAN), which are powerful tools to used analyze the test signal in a complex medium and may play an important role in future studies. The HHT bolt signal analysis method is a self-adaptive and automatic process, which can be programed as analysis software and will make bolt tests more convenient in practice.

A cooperative study of gate entry designs: Welbeck Colliery (UK) and Jim Walter Resources (USA)

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

Hendon, G.; Carr, F.; Lewis, A.

1995-11-01

Longwall developments in the UK have historically consisted of single entry gate roads. Adjacent developments were separated from existing pales by large barrier pillars (designed of sufficient width to get away from the longwall abutments of the previous panel) or by small barriers driven in the shadow, or de-stressed zone, of the previous panel. Some 2nd panel tailgates were also driven skin to skin leaving no coal barrier between the newly driven entry and the heavily supported existing gateroad. With the development and wide acceptance of fully bolted entries and the pressure to reduce production costs, alternatives to single entrymore » drivage, particularly yield pillar developments, were examined. Through the Rock Mechanics Branch of british Coal, a cooperative study was begun with Jim Walter Resources, Inc., USA, (JWR) to look at the yield pillar alternative in detail. This study was to determine the feasibility of utilizing yield pillars in the UK and to determine, through monitoring, the possibility of reducing stable pillar widths at JWR. The study has included extensive monitoring of the yield-stable-yield pillar system at JWR No. 7 Mine and an underground trial of a two entry yield pillar test area at Welbeck Colliery in the UK. This paper describes results from the JWR study and the subsequent results of the first advancing yield pillar development in the UK at Welbeck Colliery.« less

77 FR 63268 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-16

... link bolts, center sway link bolts, and thrust link bolts on the forward engine mounts. This proposed... forward engine mounts. This condition, if left uncorrected, could result in a deterioration of the structural integrity of the front engine mount bolts [and possible damage to an engine or wing]. For the...

Grace Under Pressure

NASA Technical Reports Server (NTRS)

2002-01-01

Developed in response to a NASA requirement to remotely measure tension in critical bolts on the International Space Station, the SureBolt(TM) Correlation Bolt Gage is the first ultrasonic system to capture an entire "echo" pulse for determining the change in time of flight of an ultrasonic signal traversing a fastener for tension measurement. The standard SureBolt system hardware has the capability of recording over 1 million bolt tension readings-with their complete waveforms-in Microsoft Excel-compatible format. The user- friendly Tension-Not-Torque(Copyright) software interface offers tension change graphing in real time, and a place to store field notes, special parameters, tension calibration constants, and temperature changes for each measurement. The technology has been used on fasteners as small as fine-threaded, 1-inch bolts, and as large as 18-inch-diameter by 30-foot-long tie rods. SureBolt is finding increased application within NASA and the aerospace industry, as well as in the automotive and nuclear industries.

On-line bolt-loosening detection method of key components of running trains using binocular vision

NASA Astrophysics Data System (ADS)

Xie, Yanxia; Sun, Junhua

2017-11-01

Bolt loosening, as one of hidden faults, affects the running quality of trains and even causes serious safety accidents. However, the developed fault detection approaches based on two-dimensional images cannot detect bolt-loosening due to lack of depth information. Therefore, we propose a novel online bolt-loosening detection method using binocular vision. Firstly, the target detection model based on convolutional neural network (CNN) is used to locate the target regions. And then, stereo matching and three-dimensional reconstruction are performed to detect bolt-loosening faults. The experimental results show that the looseness of multiple bolts can be characterized by the method simultaneously. The measurement repeatability and precision are less than 0.03mm, 0.09mm respectively, and its relative error is controlled within 1.09%.

Simulating the Structural Response of a Preloaded Bolted Joint

NASA Technical Reports Server (NTRS)

Knight, Norman F., Jr.; Phillips, Dawn R.; Raju, Ivatury S.

2008-01-01

The present paper describes the structural analyses performed on a preloaded bolted-joint configuration. The joint modeled was comprised of two L-shaped structures connected together using a single bolt. Each L-shaped structure involved a vertical flat segment (or shell wall) welded to a horizontal segment (or flange). Parametric studies were performed using elasto-plastic, large-deformation nonlinear finite element analyses to determine the influence of several factors on the bolted-joint response. The factors considered included bolt preload, washer-surface-bearing size, edge boundary conditions, joint segment length, and loading history. Joint response is reported in terms of displacements, gap opening, and surface strains. Most of the factors studied were determined to have minimal effect on the bolted-joint response; however, the washer-bearing-surface size affected the response significantly.

Piezoelectric Bolt Breakers and Bolt Fatigue Testers

NASA Technical Reports Server (NTRS)

Sherrit, Stewart; Badescu, Mircea; Bar-Cohen, Yoseph; Barengoltz, Jack; Heckman, Vanessa

2008-01-01

A proposed family of devices for inducing fatigue in bolts in order to break the bolts would incorporate piezoelectric actuators into resonant fixtures as in ultrasonic/ sonic drills/corers and similar devices described in numerous prior NASA Tech Briefs articles. These devices were originally intended primarily for use as safer, more-reliable, more-versatile alternatives to explosive bolts heretofore used to fasten spacecraft structures that must subsequently be separated from each other quickly on command during flight. On Earth, these devices could be used for accelerated fatigue testing of bolts. Fatigue theory suggests that a bolt subjected to both a constant-amplitude dynamic (that is, oscillatory) stress and a static tensile stress below the ultimate strength of the bolt material will fail faster than will a bolt subjected to only the dynamic stress. This suggestion would be applied in a device of the proposed type. The device would be designed so that the device and the bolt to be fatigue-tested or broken would be integral parts of an assembly (see figure). The static tension in the tightened bolt would apply not only the clamping force to hold the joined structures (if any) together but also the compression necessary for proper operation of the piezoelectric actuators as parts of a resonant structural assembly. The constant-amplitude dynamic stress would be applied to the bolt by driving the piezoelectric actuators with a sinusoidal voltage at the resonance frequency of longitudinal vibration of the assembly. The amplitude of the excitation would be made large enough so that the vibration would induce fatigue in the bolt within an acceptably short time. In the spacecraft applications or in similar terrestrial structural-separation applications, devices of the proposed type would offer several advantages over explosive bolts: Unlike explosive bolts, the proposed devices would be reusable, could be tested before final use, and would not be subject to catastrophic misfire. In fatigue-testing applications, devices of the proposed type would offer advantages of compactness and low cost, relative to conventional fatigue- testing apparatuses. In both structural- separation and fatigue-testing applications, bolts to be broken or tested could be instrumented with additional ultrasonic transducers for monitoring of pertinent physical properties and of fatigue failure processes.

HIV-1 Env C2-V4 Diversification in a Slow-Progressor Infant Reveals a Flat but Rugged Fitness Landscape

PubMed Central

Smith, S. Abigail; Wood, Charles; West, John T.

2013-01-01

Human immunodeficiency virus type-1 (HIV-1) fitness has been associated with virus entry, a process mediated by the envelope glycoprotein (Env). We previously described Env genetic diversification in a Zambian, subtype C infected, slow-progressor child (1157i) in parallel with an evolving neutralizing antibody response. Because of the role the Variable-3 loop (V3) plays in transmission, cell tropism, neutralization sensitivity, and fitness, longitudinally isolated 1157i C2-V4 alleles were cloned into HIV-1NL4-3-eGFP and -DsRed2 infectious molecular clones. The fluorescent reporters allowed for dual-infection competitions between all patient-derived C2-V4 chimeras to quantify the effect of V3 diversification and selection on fitness. ‘Winners’ and ‘losers’ were readily discriminated among the C2-V4 alleles. Exceptional sensitivity for detection of subtle fitness differences was revealed through analysis of two alleles differing in a single synonymous amino acid. However, when the outcomes of N = 33 competitions were averaged for each chimera, the aggregate analysis showed that despite increasing diversification and divergence with time, natural selection of C2-V4 sequences in this individual did not appear to be producing a ‘survival of the fittest’ evolutionary pattern. Rather, we detected a relatively flat fitness landscape consistent with mutational robustness. Fitness outcomes were then correlated with individual components of the entry process. Env incorporation into particles correlated best with fitness, suggesting a role for Env avidity, as opposed to receptor/coreceptor affinity, in defining fitness. Nevertheless, biochemical analyses did not identify any step in HIV-1 entry as a dominant determinant of fitness. Our results lead us to conclude that multiple aspects of entry contribute to maintaining adequate HIV-1 fitness, and there is no surrogate analysis for determining fitness. The capacity for subtle polymorphisms in Env to nevertheless significantly impact viral fitness suggests fitness is best defined by head-to-head competition. PMID:23638182

Impact of Nonlinearity of The Contact Layer Between Elements Joined in a Multi-Bolted System on Its Preload

NASA Astrophysics Data System (ADS)

Grzejda, R.

2017-12-01

The paper deals with modelling and calculations of asymmetrical multi-bolted joints at the assembly stage. The physical model of the joint is based on a system composed of four subsystems, which are: a couple of joined elements, a contact layer between the elements, and a set of bolts. The contact layer is assumed as the Winkler model, which can be treated as a nonlinear or linear model. In contrast, the set of bolts are modelled using simplified beam models, known as spider bolt models. The theorem according to which nonlinearity of the contact layer has a negligible impact on the final preload of the joint in the case of its sequential tightening has been verified. Results of sample calculations for the selected multi-bolted system, in the form of diagrams of preloads in the bolts as well as normal contact pressure between the joined elements during the assembly process and at its end, are presented.

3-Dimensional Analysis of Deformation of Disk Wheels and Transverse Force of Wheel Bolts

NASA Astrophysics Data System (ADS)

Kagiwada, Tadao; Harada, Hiroyuki

Loosening of the wheel nuts, which fix the disk wheels of automobiles to the wheel hub, may be the cause of accidents where the wheel falls off while the automobile is running. When the transverse force of wheel bolts exceeds a certain proportion of the bolt shaft force, the wheel nut begins to loosen. Further, the force on the bolt shaft may also be influenced by the loads acting to the wheel through the moment caused by the offset of the wheel. This study determined the 3-dimensional deformation of the disk wheels and the transverse forces on the wheel bolt by 3-dimensional numerical analysis. The results established that the transverse force was influenced by the bolt shaft force caused by the bolt fastening and was superposed on that due to the load, and that it fluctuated greatly during the revolution of the wheel. This phenomenon may be a large factor in the loosening of wheel nuts.

The research on delayed fracture behavior of high-strength bolts in steel structure

NASA Astrophysics Data System (ADS)

Li, Guo dong; Li, Nan

2017-07-01

High-strength bolts have been widely used in power plants. However, the high-strength bolts which being employed in pumping station, steel structure and pipeline anti-whip structure have been found delayed fracture for many times in a power plant, this will affect the reliability of steel fracture and bring blow risk caused by falling objects. The high-strength bolt with delayed fracture was carried out fracture analysis, metallurgical analysis, chemical analysis, mechanical analysis, as well as bolts installation analysis, it can be comprehensively confirmed that the direct cause of high-strength bolts delayed fracture is the stress corrosion, and the root cause of high-strength bolts delayed fracture should be the improper installation at the initial and the imperfect routine anti-corrosion maintenance.

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

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

Influence of bolt tightening torque, wire size, and component reuse on wire fixation in circular external fixation.

PubMed

Wosar, Marc A; Marcellin-Little, Denis J; Roe, Simon C

2002-01-01

To evaluate the effects of bolt torque, wire size, and component reuse on the ability to maintain wire tension in 3 external skeletal fixation systems. Biomechanical study. Yield strength in tension of 1.0-, 1.2-, 1.5-, and 1.6-mm-diameter wires, and yield strength in torque of Hofmann Small Bone Fixation (SBF) cannulated and slotted bolts and IMEX regular and miniature bolts were determined on a testing machine. The minimum bolt tightening torque needed to prevent wire slippage at clinically recommended wire tensions was determined. Components were tested 10 times, and loads at slippage were recorded. The IMEX system required a mean of 8 Nm of bolt tightening torque to maintain 900 N (1.6-mm wires). The SBF system required a mean of 3 Nm bolt torque to maintain 300 N (1.0-mm wires) and 5 Nm to maintain 600 N (1.2-mm wires). The SBF cannulated bolt required 9 Nm of torque to maintain 900 N (1.5-mm wires). The SBF slotted bolts could only maintain 800 N before yield. The IMEX miniature system required a mean bolt torque of 1.1 Nm to maintain 300 N. The cannulated and slotted bolts from both manufacturers failed to maintain 70% of initial wire tension after 7 and 4 uses, respectively. The IMEX systems and the SBF system using 1.0- and 1.2-mm wires could maintain clinically recommended wire tension safely. Only the IMEX system could maintain clinically recommended wire tension safely using 1.5- or 1.6-mm wires. The SBF system using 1.0- and 1.2-mm wires and the IMEX system using all wire sizes can maintain clinically relevant wire tension. The SBF system using 1.5-mm wires could not. Cannulated and slotted bolts should not be used more than 6 and 3 times, respectively. Nuts should not be reused. Copyright 2002 by The American College of Veterinary Surgeons

Matching nuts and bolts in O(n log n) time

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

Komlos, J.; Ma, Yuan; Szemeredi, E.

Given a set of n nuts of distinct widths and a set of n bolts such that each nut corresponds to a unique bolt of the same width, how should we match every nut with its corresponding bolt by comparing nuts with bolts (no comparison is allowed between two nuts or between two bolts)? The problem can be naturally viewed as a variant of the classic sorting problem as follows. Given two lists of n numbers each such that one list is a permutation of the other, how should we sort the lists by comparisons only between numbers in differentmore » lists? We give an O(n log n)-time deterministic algorithm for the problem. This is optimal up to a constant factor and answers an open question posed by Alon, Blum, Fiat, Kannan, Naor, and Ostrovsky. Moreover, when copies of nuts and bolts are allowed, our algorithm runs in optimal O(log n) time on n processors in Valiant`s parallel comparison tree model. Our algorithm is based on the AKS sorting algorithm with substantial modifications.« less

Locking Nut and Bolt

NASA Technical Reports Server (NTRS)

Bishop, R.

1983-01-01

Threaded fastener locks parts securely together despite together large loosening torques, even under conditions of high temperature and vibration. Positive locking action is suitable for use where conventional fasteners tend to work loose--for example, on high-speed rotating machinery. Bolt, nut and key are joined together so key occupies alined slots in bolt and nut and prevents nut from rotating off bolt.

Bolt axial stress measurement based on a mode-converted ultrasound method using an electromagnetic acoustic transducer.

PubMed

Ding, Xu; Wu, Xinjun; Wang, Yugang

2014-03-01

A method is proposed to measure the stress on a tightened bolt using an electromagnetic acoustic transducer (EMAT). A shear wave is generated by the EMAT, and a longitudinal wave is obtained from the reflection of the shear wave due to the mode conversion. The ray paths of the longitudinal and the shear wave are analyzed, and the relationship between the bolt axial stress and the ratio of time of flight between two mode waves is then formulated. Based on the above outcomes, an EMAT is developed to measure the bolt axial stress without loosening the bolt, which is required in the conventional EMAT test method. The experimental results from the measurement of the bolt tension show that the shear and the mode-converted longitudinal waves can be received successfully, and the ratio of the times of flight of the shear and the mode-converted longitudinal waves is linearly proportional to the bolt axial tension. The non-contact characteristic of EMAT eliminates the effect of the couplant and also makes the measurement more convenient than the measurement performed using the piezoelectric transducer. This method provides a promising way to measure the stress on tightened bolts. Copyright © 2013 Elsevier B.V. All rights reserved.

Bolt-Tension Sensor

NASA Technical Reports Server (NTRS)

Goldie, James H.; Bushko, Dariusz A.; Gerver, Michael J.

1995-01-01

In technique for measuring tensile force of bolt, specially fabricated magnetostrictive washer used as force transducer. Compact, portable inductive electronic sensor placed against washer to measure tension force. New system provides accurate, economical, and convenient way to measure bolt tension in field. Measurements on test assembly shows that tension can be measured to accuracy of about plus or minus 1 percent of load capacity of typical bolt.

Evaluation of mounting bolt loads for Space Shuttle Get Away Special (GAS) adapter beam

NASA Technical Reports Server (NTRS)

Talapatra, D. C.

1983-01-01

During the prototype vibration tests of the GAS adapter beam, significant impacting of the beam at its support points was observed. The cause of the impacting was traced to gaps under the mounting bolt heads. Because of the nonlinear nature of the response, it was difficult to evaluate the effects which Shuttle launch dynamics might have on the mounting bolt loads. A series of tests were conducted on an electrodynamic exciter in which the transient acceleration time histories, which had been measured during the Space Transportation System-1 (STS-1; Space Shuttle mission 1) launch, were simulated. The actual flight data had to be filtered and compensated so that it could be reproduced on the shaker without exceeding displacement and velocity limitations. Mounting bolt loads were measured directly by strain gages applied to the bolts. Various gap thicknesses and bolt torques were investigated. Although increased gap thickness resulted in greater accelerations due to impacting, the bolt loads were not significantly affected. This is attributed to the fact that impacting excited mostly higher frequency modes which do not have significant modal mass.

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 13682 - Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-23

... retention bolt, a reverse orientation of the retention bolt and a rework of the weight on wheel (WOW... reverse orientation of the retention bolt and a rework of the weight on wheel (WOW) proximity sensor cover...

Evidence for a pheromone in the locust borer

Treesearch

Jimmy R. Galford

1977-01-01

Laboratory studies have suggested the existence of a pheromone in the locust borer. Male beetles spent more time on bolts of wood exposed to virgin females than on control bolts. The females apparently deposited the pheromone on the bolts of wood and filter paper.

Efficient finite element modelling for the investigation of the dynamic behaviour of a structure with bolted joints

NASA Astrophysics Data System (ADS)

Omar, R.; Rani, M. N. Abdul; Yunus, M. A.; Mirza, W. I. I. Wan Iskandar; Zin, M. S. Mohd

2018-04-01

A simple structure with bolted joints consists of the structural components, bolts and nuts. There are several methods to model the structures with bolted joints, however there is no reliable, efficient and economic modelling methods that can accurately predict its dynamics behaviour. Explained in this paper is an investigation that was conducted to obtain an appropriate modelling method for bolted joints. This was carried out by evaluating four different finite element (FE) models of the assembled plates and bolts namely the solid plates-bolts model, plates without bolt model, hybrid plates-bolts model and simplified plates-bolts model. FE modal analysis was conducted for all four initial FE models of the bolted joints. Results of the FE modal analysis were compared with the experimental modal analysis (EMA) results. EMA was performed to extract the natural frequencies and mode shapes of the test physical structure with bolted joints. Evaluation was made by comparing the number of nodes, number of elements, elapsed computer processing unit (CPU) time, and the total percentage of errors of each initial FE model when compared with EMA result. The evaluation showed that the simplified plates-bolts model could most accurately predict the dynamic behaviour of the structure with bolted joints. This study proved that the reliable, efficient and economic modelling of bolted joints, mainly the representation of the bolting, has played a crucial element in ensuring the accuracy of the dynamic behaviour prediction.

Behavior of a tapered hub flange with a bolted flat cover in transient temperature field

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

Sawa, T.; Nakagomi, Y.; Hirose, T.

1996-02-01

When bolted flange connections with gaskets are used in mechanical structures such as pipe connections, bolted covers of casks, and pressure vessels in nuclear and chemical plants and cylinder heads in internal combustion engines, they are usually subjected to transient thermal conditions. An experimental and analytical study was made on a bolted connection subjected to thermal loading. The connection consists of an aluminum alloy tapered hub flange and a flat cover, including a gasket fastened by steel bolts and nuts. Temperature distribution in the connection was measured with thermocouples, and the axial bolt force, the maximum bolt stress, and themore » hub stress were measured by strain gages under a thermal condition that the inner surface of the flanges was heated and the outer surfaces of the flanges and the cover were held at room temperature. Finite difference analysis was made to obtain the temperature distributions in the connection due to a transient thermal condition. This paper demonstrates the method for obtaining an increment in axial bolt force and the maximum bolt stress. In all cases, the analytical results were fairly consistent with the experimental results.« less

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.

Study on Fatigue Performance of Composite Bolted Joints with Bolt-Hole Delamination

NASA Astrophysics Data System (ADS)

Liu, M. J.; Yu, S.; Zhao, Q. Y.

2018-03-01

Fatigue performance of composite structure with imperfections is a challenging subject at present. Based on cohesive zone method and multi-continuum theory, delamination evolution response and fatigue life prediction of a 3D composite single-lap joint with a bolt-hole have been investigated through computer codes Abaqus and Fe-safe. Results from the comparison of a perfect composite bolted joint with another defect one indicates that a relatively small delamination damage around the bolt hole brings about significant degradation of local material performance. More notably, fatigue life of stress concentration region of composite bolted joints is highly sensitive to external loads, as an increase of 67% cyclic load amplitude leads to an decrease of 99.5% local fatigue life in this study. However, the numerical strategy for solving composite fatigue problems is meaningful to engineering works.

Mold bolt and means for achieving close tolerances between bolts and bolt holes

NASA Technical Reports Server (NTRS)

Johnston, David L. (Inventor); Bryant, Phillip G. (Inventor)

1993-01-01

In the space shuttle, a cargo bay storage rack was required which was to be manufactured from a metal-plastic composite and bolted to a cargo structure. Following completion, utilization of the rack was disallowed due to tolerances, that is, the size differences between the outside bolt diameter and the inside hole diameter. In addition to the space shuttle problem there are other close tolerance requirements for bolts. Such environments often benefit from close tolerance bolting. Frequently such fabrication is not cost effective. Consequently there is a need for means of achieving close tolerances between bolts and bolt holes. Such means are provided. After compressing the elements together a strong rigid plastic, ceramic, or ceramic plastic fluid is forced into a channel extending through the bolt.

Post-Service Examination of PWR Baffle Bolts, Part I. Examination and Test Plan

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

Leonard, Keith J.; Sokolov, Mikhail A.; Gussev, Maxim N.

2015-04-30

In support of extended service and current operations of the US nuclear reactor plants, the Oak Ridge National Laboratory (ORNL), through the Department of Energy (DOE), Light Water Reactor Sustainability (LWRS) Program, is coordinating with Ginna Nuclear Power Plant, The Westinghouse Electric Company, LLC, and ATI Consulting, the selective procurement of baffle bolts that were withdrawn from service in 2011 and currently stored on site at Ginna. The goal of this program is to perform detailed microstructural and mechanical property characterization of baffle former bolts following in-service exposures. This report outlines the selection criteria of the bolts and the techniquesmore » to be used in this study. The bolts available are the original alloy 347 steel fasteners used in holding the baffle plates to the baffle former structures within the lower portion of the pressurized water reactor vessel. Of the eleven possible bolts made available for this work, none were identified to have specific damage. The bolts, however, did show varying levels of breakaway torque required in their removal. The bolts available for this study varied in peak fluence (highest dose within the head of the bolt) between 9.9 and 27.8x10 21 n/cm 2 (E>1MeV). As no evidence for crack initiation was determined for the available bolts from preliminary visual examination, two bolts with the higher fluence values were selected for further post-irradiation examination. The two bolts showed different breakaway torque levels necessary in their removal. The information from these bolts will be integral to the LWRS program initiatives in evaluating end of life microstructure and properties. Furthermore, valuable data will be obtained that can be incorporated into model predictions of long-term irradiation behavior and compared to results obtained in high flux experimental reactor conditions. The two bolts selected for the ORNL study will be shipped to Westinghouse with bolts of interest to their collaborative efforts with the Electric Power Research Institute. Westinghouse will section the ORNL bolts into samples specified in this report and return them to ORNL. Samples will include bend bars for fracture toughness and crack propagation studies along with thin sections from which specimens for bend testing, subscale tensile and microstructural analysis can be obtained. Additional material from the high stress concentration region at the transition between the bolt head and shank will also be preserved to allow for further investigation of possible crack initiation sites.« less

A Component-Based Study of the Effect of Diameter on Bond and Anchorage Characteristics of Blind-Bolted Connections.

PubMed

Amin, Muhammad Nasir; Zaheer, Salman; Alazba, Abdulrahman Ali; Saleem, Muhammad Umair; Niazi, Muhammad Umar Khan; Khurram, Nauman; Amin, Muhammad Tahir

2016-01-01

Structural hollow sections are gaining worldwide importance due to their structural and architectural advantages over open steel sections. The only obstacle to their use is their connection with other structural members. To overcome the obstacle of tightening the bolt from one side has given birth to the concept of blind bolts. Blind bolts, being the practical solution to the connection hindrance for the use of hollow and concrete filled hollow sections play a vital role. Flowdrill, the Huck High Strength Blind Bolt and the Lindapter Hollobolt are the well-known commercially available blind bolts. Although the development of blind bolts has largely resolved this issue, the use of structural hollow sections remains limited to shear resistance. Therefore, a new modified version of the blind bolt, known as the "Extended Hollo-Bolt" (EHB) due to its enhanced capacity for bonding with concrete, can overcome the issue of low moment resistance capacity associated with blind-bolted connections. The load transfer mechanism of this recently developed blind bolt remains unclear, however. This study uses a parametric approach to characterising the EHB, using diameter as the variable parameter. Stiffness and load-carrying capacity were evaluated at two different bolt sizes. To investigate the load transfer mechanism, a component-based study of the bond and anchorage characteristics was performed by breaking down the EHB into its components. The results of the study provide insight into the load transfer mechanism of the blind bolt in question. The proposed component-based model was validated by a spring model, through which the stiffness of the EHB was compared to that of its components combined. The combined stiffness of the components was found to be roughly equivalent to that of the EHB as a whole, validating the use of this component-based approach.

Natural frequency identification of smart washer by using adaptive observer

NASA Astrophysics Data System (ADS)

Ito, Hitoshi; Okugawa, Masayuki

2014-04-01

Bolted joints are used in many machines/structures and some of them have been loosened during long time use, and unluckily these bolt loosening may cause a great accident of machines/structures system. These bolted joint, especially in important places, are main object of maintenance inspection. Maintenance inspection with human- involvement is desired to be improved owing to time-consuming, labor-intensive and high-cost. By remote and full automation monitoring of the bolt loosening, constantly monitoring of bolted joint is achieved. In order to detect loosening of bolted joints without human-involvement, applying a structural health monitoring technique and smart structures/materials concept is the key objective. In this study, a new method of bolt loosening detection by adopting a smart washer has been proposed, and the basic detection principle was discussed with numerical analysis about frequency equation of the system, was confirmed experimentally. The smart washer used in this study is in cantilever type with piezoelectric material, which adds the washer the self-sensing and actuation function. The principle used to detect the loosening of the bolts is a method of a bolt loosening detection noted that the natural frequency of a smart washer system is decreasing by the change of the bolt tightening axial tension. The feature of this proposed method is achieving to identify the natural frequency at current condition on demand by adopting the self-sensing and actuation function and system identification algorithm for varying the natural frequency depending the bolt tightening axial tension. A novel bolt loosening detection method by adopting adaptive observer is proposed in this paper. The numerical simulations are performed to verify the possibility of the adaptive observer-based loosening detection. Improvement of the detection accuracy for a bolt loosening is confirmed by adopting initial parameter and variable adaptive gain by numerical simulation.

Bolts Salvaged From Cull Oaks

Treesearch

B. E. Carpenter

1959-01-01

But how about bolts from cull oaks on upland pine sites? Though a bolt operation in such material offers many difficulties, at least one Southern firm is currently trying it. That firm is Potlatch Forests, Inc., of Warren, Arkansas.

Universal Assembly for Captive Bolts

NASA Technical Reports Server (NTRS)

Marke, M. L.; Hagopian, B.

1982-01-01

New method allows for virtually any bolt to be easily converted to "captive" bolt. Method eliminates need for separate design for each application. Cup-shaped washer that is flattened secures tap to bolt. Wire attached to tab holds bolt assembly captive. Flattening washer can also be done during installation of bolt. Wash, tab and spacer are all made of corrosion-resistant steel.

46 CFR 56.25-20 - Bolting.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., Blanks, Flange Facings, Gaskets, and Bolting § 56.25-20 Bolting. (a) General. (1) Bolts, studs, nuts, and....01-2). (2) Bolts and studs must extend completely through the nuts. (3) See § 58.30-15(c) of this... steel stud bolts must be threaded full length or, if desired, may have reduced shanks of a diameter not...

Experimental study of canvas characterization for paintings

NASA Astrophysics Data System (ADS)

Cornelis, Bruno; Dooms, Ann; Munteanu, Adrian; Cornelis, Jan; Schelkens, Peter

2010-02-01

The work described here fits in the context of a larger project on the objective and relevant characterization of paintings and painting canvas through the analysis of multimodal digital images. We captured, amongst others, X-ray images of different canvas types, characterized by a variety of textures and weave patterns (fine and rougher texture; single thread and multiple threads per weave), including raw canvas as well as canvas processed with different primers. In this paper, we study how to characterize the canvas by extracting global features such as average thread width, average distance between successive threads (i.e. thread density) and the spatial distribution of primers. These features are then used to construct a generic model of the canvas structure. Secondly, we investigate whether we can identify different pieces of canvas coming from the same bolt. This is an important element for dating, authentication and identification of restorations. Both the global characteristics mentioned earlier and some local properties (such as deviations from the average pattern model) are used to compare the "fingerprint" of different pieces of cloth coming from the same or different bolts.

Differentiating RNA from DNA by a molecular fluorescent probe based on the "door-bolt" mechanism biomaterials.

PubMed

Yao, Qichao; Li, Haidong; Xian, Liman; Xu, Feng; Xia, Jing; Fan, Jiangli; Du, Jianjun; Wang, Jingyun; Peng, Xiaojun

2018-09-01

Although excellent florescent probes have been developed for DNA, good probes for RNA remain lacking. The shortage of reported and commercial RNA probes is attributable to their severe interference from DNA. As DNA and RNA have similar structures but different functions, it has been an imperative challenge to develop RNA probes that differentiate from DNA. In this study, an NIR fluorescent probe, NBE, is described, which contains a bulky julolidine group that can fit in a spacious RNA pocket and emit intense fluorescence. However, NBE has no response to DNA, as it cannot intercalate into the double strands or even in the DNA minor groove. The sensing mechanism is similar to the effect of a door-bolt. NBE shows excellent performance in RNA sensing (outstanding photostability, high selectivity and fast response), whether in aqueous buffers, fixed cells or living cells. These findings might provide not only a potential imaging tool but also a new design strategy for the recognition of RNA while avoiding interference from DNA. Copyright © 2018 Elsevier Ltd. All rights reserved.

Design and evaluation of a bolted joint for a discrete carbon-epoxy rod-reinforced hat section

NASA Technical Reports Server (NTRS)

Rousseau, Carl Q.; Baker, Donald J.

1996-01-01

The use of prefabricated pultruded carbon-epoxy rods has reduced the manufacturing complexity and costs of stiffened composite panels while increasing the damage tolerance of the panels. However, repairability of these highly efficient discrete stiffeners has been a concern. Design, analysis, and test results are presented in this paper for a bolted-joint repair for the pultruded rod concept that is capable of efficiently transferring axial loads in a hat-section stiffener on the upper skin segment of a heavily loaded aircraft wing component. A tension and a compression joint design were evaluated. The tension joint design achieved approximately 1.0% strain in the carbon-epoxy rod-reinforced hat-section and failed in a metal fitting at 166% of the design ultimate load. The compression joint design failed in the carbon-epoxy rod-reinforced hat-section test specimen area at approximately 0.7% strain and at 110% of the design ultimate load. This strain level of 0.7% in compression is similar to the failure strain observed in previously reported carbon-epoxy rod-reinforced hat-section column tests.

System 6: making frame-quality blanks from white oak thinnings

Treesearch

Hugh W. Reynolds; Philip A. Araman

1983-01-01

Low-grade white oak timber removed during a timber stand improvement cut on the Jefferson National Forest in Virginia was made into sawlogs, poles, 6-foot bolts, 4-foot bolts, pulpwood, and firewood. The 6-foot bolts were sawed to two cants per bolt; cants were resawed to 4/4 System 6 boards; boards were dried to 6 percent moisture content and made into frame blanks...

Causes of Failure of High-Tensile Stud Bolts Used for Joining Metal Parts of Tower Crane

NASA Astrophysics Data System (ADS)

Tingaev, A. K.; Gubaydulin, R. G.; Shaburova, N. A.

2017-11-01

The causes of the failure of a high-tensile stud 2M48-6gx500 10.9 made from steel grade 30HGSA which led to a temporary inoperability of a tower crane were investigated. The bolts were used to assemble the tower sections and collapsed after 45 days from the moment the crane was commissioned. The cracks in the fracture are identified as fatigue with the characteristic sites of nucleation, sustainable development and static dolomite. To determine the possible causes of stud bolts destruction, metallographic, durometric and mechanical tests were carried out from which it follows that the stud bolt material in its original state corresponded to the delivery conditions. The destruction of the stud bolt appears to have resulted from a combination of several unfavorable factors: uncertainty about the actual tension of the stud bolt due to the lack of information about the magnitude of the twist factor; partial displacement of the centers of the brackets holes and rotation of the stud bolt axis during the sections’ assembly; no tight contact on the support surfaces of the section brackets. All this led to a discrepancy between the actual design of the stud bolt, the appearance of additional forces and the destruction of the stud bolt.

Measurement of the Length of Installed Rock Bolt Based on Stress Wave Reflection by Using a Giant Magnetostrictive (GMS) Actuator and a PZT Sensor.

PubMed

Luo, Mingzhang; Li, Weijie; Wang, Bo; Fu, Qingqing; Song, Gangbing

2017-02-23

Rock bolts, as a type of reinforcing element, are widely adopted in underground excavations and civil engineering structures. Given the importance of rock bolts, the research outlined in this paper attempts to develop a portable non-destructive evaluation method for assessing the length of installed rock bolts for inspection purposes. Traditionally, piezoelectric elements or hammer impacts were used to perform non-destructive evaluation of rock bolts. However, such methods suffered from many major issues, such as the weak energy generated and the requirement for permanent installation for piezoelectric elements, and the inconsistency of wave generation for hammer impact. In this paper, we proposed a portable device for the non-destructive evaluation of rock bolt conditions based on a giant magnetostrictive (GMS) actuator. The GMS actuator generates enough energy to ensure multiple reflections of the stress waves along the rock bolt and a lead zirconate titantate (PZT) sensor is used to detect the reflected waves. A new integrated procedure that involves correlation analysis, wavelet denoising, and Hilbert transform was proposed to process the multiple reflection signals to determine the length of an installed rock bolt. The experimental results from a lab test and field tests showed that, by analyzing the instant phase of the periodic reflections of the stress wave generated by the GMS transducer, the length of an embedded rock bolt can be accurately determined.

Measurement of the Length of Installed Rock Bolt Based on Stress Wave Reflection by Using a Giant Magnetostrictive (GMS) Actuator and a PZT Sensor

PubMed Central

Luo, Mingzhang; Li, Weijie; Wang, Bo; Fu, Qingqing; Song, Gangbing

2017-01-01

Rock bolts, as a type of reinforcing element, are widely adopted in underground excavations and civil engineering structures. Given the importance of rock bolts, the research outlined in this paper attempts to develop a portable non-destructive evaluation method for assessing the length of installed rock bolts for inspection purposes. Traditionally, piezoelectric elements or hammer impacts were used to perform non-destructive evaluation of rock bolts. However, such methods suffered from many major issues, such as the weak energy generated and the requirement for permanent installation for piezoelectric elements, and the inconsistency of wave generation for hammer impact. In this paper, we proposed a portable device for the non-destructive evaluation of rock bolt conditions based on a giant magnetostrictive (GMS) actuator. The GMS actuator generates enough energy to ensure multiple reflections of the stress waves along the rock bolt and a lead zirconate titantate (PZT) sensor is used to detect the reflected waves. A new integrated procedure that involves correlation analysis, wavelet denoising, and Hilbert transform was proposed to process the multiple reflection signals to determine the length of an installed rock bolt. The experimental results from a lab test and field tests showed that, by analyzing the instant phase of the periodic reflections of the stress wave generated by the GMS transducer, the length of an embedded rock bolt can be accurately determined. PMID:28241503

A One-Hand Nut and Bolt Assembly Tool

NASA Technical Reports Server (NTRS)

Spencer, J. M.

1984-01-01

Special wrench speeds nut and bolt assembly when insufficient room to hold nut behind bolthole with standard tool. C-clamp shaped box-andsocket-wrench assembly holds nut on blind side in alinement to receive bolt from open side.

Suitable pitch difference to realize anti-loosening performance for various bolts-nuts diameter

NASA Astrophysics Data System (ADS)

Kubo, S.; Tateishi, K.; Noda, N.-A.; Sano, Y.; Takase, Y.; Honda, K.

2018-06-01

In bolt-nut connection, the anti-loosening performance and high fatigue strength are always required with low cost to ensure the connected structure’s safety. In the previous study, a suitable pitch difference between the bolt-nut was obtained as α = 33 μm for M16 JIS bolt- nut through loosening experiment and FEM simulation for tightening process. However, other bolt-nut diameters have not been considered yet. In this paper, therefore, suitable pitch difference is considered for various diameters to realize anti-loosening performance. Since bolt-nut thread geometries are different depending on the diameter, they are expressed as approximate formula. Then, loosening force and anti-loosening force are considered by varying the diameter. Finally, suitable pitch difference {α }minsuit< α < {α }maxsuit was determined from mechanical condition.

Calculation of parameters of combined frame and roof bolting

NASA Astrophysics Data System (ADS)

Ivanov, S. I.; Titov, N. V.; Privalov, A. A.; Trunov, I. T.; Sarychev, V. I.

2017-10-01

The paper presents the method of calculation of the combined frame and roof bolting. Recommendations on providing joint operation of roof bolting with steel support frames are given. Graphs for determining standard rock movement, as well as for defining proof load on the yielding support, were developed.

Crashworthiness Design of the Shear Bolts for Light Collision Safety Devices

NASA Astrophysics Data System (ADS)

Kim, Jin Sung; Huh, Hoon; Kwon, Tae Soo

This paper introduces the jig set for the crash test and the crash test results of shear bolts which are designed to fail at train crash conditions. The tension and shear bolts are attached to Light Collision Safety Devices(LCSD) as a mechanical fuse when tension and shear bolts reach their failure load designed. The kinetic energy due to the crash is absorbed by the secondary energy absorbing device after LCSD are detached from the main body by the fracture of shear bolts. A single shear bolt was designed to fail at the load of 250 kN. The jig set designed to convert a compressive loading to a shear loading was installed to the high speed crash tester for dynamic shear tests. Two strain gauges were attached at the parallel section of the jig set to measure the load responses acting on the shear bolts. Crash tests were performed with a carrier whose mass was 250 kg and the initial speed of the carrier was 9 m/sec. From the quasi-static and dynamic experiments as well as the numerical analysis, the capacity of the shear bolts were accurately predicted for the crashworthiness design.

A Component-Based Study of the Effect of Diameter on Bond and Anchorage Characteristics of Blind-Bolted Connections

PubMed Central

Amin, Muhammad Nasir; Zaheer, Salman; Alazba, Abdulrahman Ali; Saleem, Muhammad Umair; Niazi, Muhammad Umar Khan; Khurram, Nauman; Amin, Muhammad Tahir

2016-01-01

Structural hollow sections are gaining worldwide importance due to their structural and architectural advantages over open steel sections. The only obstacle to their use is their connection with other structural members. To overcome the obstacle of tightening the bolt from one side has given birth to the concept of blind bolts. Blind bolts, being the practical solution to the connection hindrance for the use of hollow and concrete filled hollow sections play a vital role. Flowdrill, the Huck High Strength Blind Bolt and the Lindapter Hollobolt are the well-known commercially available blind bolts. Although the development of blind bolts has largely resolved this issue, the use of structural hollow sections remains limited to shear resistance. Therefore, a new modified version of the blind bolt, known as the “Extended Hollo-Bolt” (EHB) due to its enhanced capacity for bonding with concrete, can overcome the issue of low moment resistance capacity associated with blind-bolted connections. The load transfer mechanism of this recently developed blind bolt remains unclear, however. This study uses a parametric approach to characterising the EHB, using diameter as the variable parameter. Stiffness and load-carrying capacity were evaluated at two different bolt sizes. To investigate the load transfer mechanism, a component-based study of the bond and anchorage characteristics was performed by breaking down the EHB into its components. The results of the study provide insight into the load transfer mechanism of the blind bolt in question. The proposed component-based model was validated by a spring model, through which the stiffness of the EHB was compared to that of its components combined. The combined stiffness of the components was found to be roughly equivalent to that of the EHB as a whole, validating the use of this component-based approach. PMID:26901866

Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM

NASA Technical Reports Server (NTRS)

Jullien, Pierre

2008-01-01

During re-entry, spacecrafts are subjected to extreme thermal loads. On mars, they may go through dust storms. These external heat loads are leading the design of re-entry vehicles or are affecting it for spacecraft facing solid propellant jet stream. Sizing the Thermal Protection System require a good knowledge of such solicitations and means to model and reproduce them on earth. Through its work on European projects, ASTRIUM has developed the full range of competences to deal with such issues. For instance, we have designed and tested the heat-shield of the Huygens probe which landed on Titan. In particular, our plasma generators aim to reproduce a wide variety of re-entry conditions. Heat loads are generated by the huge speed of the probes. Such conditions cannot be fully reproduced. Ground tests focus on reproducing local aerothermal loads by using slower but hotter flows. Our inductive plasma torch enables to test little samples at low TRL. Amongst the arc-jets, one was design to test architecture design of ISS crew return system and others fit more severe re-entry such as sample returns or Venus re-entry. The last developments aimed in testing samples in seeded flows. First step was to design and test the seeding device. Special diagnostics characterizing the resulting flow enabled us to fit it to the requirements.

Growth of Larval Agrilus planipennis (Coleoptera: Buprestidae) and Fitness of Tetrastichus planipennisi (Hymenoptera: Eulophidae) in Blue Ash (Fraxinus quadrangulata) and Green Ash (F. pennsylvanica).

PubMed

Peterson, Donnie L; Duan, Jian J; Yaninek, J S; Ginzel, Matthew D; Sadof, Clifford S

2015-12-01

Emerald ash borer (Agrilus planipennis Fairmaire) is an invasive primary pest of North American ash (Fraxinus spp.) trees. Blue ash (F. quadrangulata) is less susceptible to emerald ash borer infestations in the forest than other species of North American ash. Whereas other studies have examined adult host preferences, we compared the capacity of emerald ash borer larvae reared from emerald ash borer eggs in the field and in the laboratory to survive and grow in blue ash and the more susceptible green ash (F. pennsylvanica). Emerald ash borer larval survivorship was the same on both ash species. Mortality due to wound periderm formation was only observed in living field grown trees, but was low (<4%) in both green and blue ash. No difference in larval mortality in the absence of natural enemies suggests that both green and blue ash can support the development of emerald ash borer. Larvae reared from eggs on blue ash were smaller than on green ash growing in the field and also in bolts that were infested under laboratory conditions. In a laboratory study, parasitism rates of confined Tetrastichus planipennisi were similar on emerald ash borer larvae reared in blue and green ash bolts, as were fitness measures of the parasitoid including brood size, sex ratio, and adult female size. Thus, we postulate that emerald ash borer larvae infesting blue ash could support populations of T. planipennisi and serve as a potential reservoir for this introduced natural enemy after most of the other native ash trees have been killed. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Structural fatigue test results for large wind turbine blade sections

NASA Technical Reports Server (NTRS)

Faddoul, J. R.; Sullivan, T. L.

1982-01-01

In order to provide quantitative information on the operating life capabilities of wind turbine rotor blade concepts for root-end load transfer, a series of cantilever beam fatigue tests was conducted. Fatigue tests were conducted on a laminated wood blade with bonded steel studs, a low cost steel spar (utility pole) with a welded flange, a utility pole with additional root-end thickness provided by a swaged collar, fiberglass spars with both bonded and nonbonded fittings, and, finally, an aluminum blade with a bolted steel fitting (Lockheed Mod-0 blade). Photographs, data, and conclusions for each of these tests are presented. In addition, the aluminum blade test results are compared to field failure information; these results provide evidence that the cantilever beam type of fatigue test is a satisfactory method for obtaining qualitative data on blade life expectancy and for identifying structurally underdesigned areas (hot spots).

Development of a Unified Rock Bolt Model in Discontinuous Deformation Analysis

NASA Astrophysics Data System (ADS)

He, L.; An, X. M.; Zhao, X. B.; Zhao, Z. Y.; Zhao, J.

2018-03-01

In this paper, a unified rock bolt model is proposed and incorporated into the two-dimensional discontinuous deformation analysis. In the model, the bolt shank is discretized into a finite number of (modified) Euler-Bernoulli beam elements with the degrees of freedom represented at the end nodes, while the face plate is treated as solid blocks. The rock mass and the bolt shank deform independently, but interact with each other through a few anchored points. The interactions between the rock mass and the face plate are handled via general contact algorithm. Different types of rock bolts (e.g., Expansion Shell, fully grouted rebar, Split Set, cone bolt, Roofex, Garford and D-bolt) can be realized by specifying the corresponding constitutive model for the tangential behavior of the anchored points. Four failure modes, namely tensile failure and shear failure of the bolt shank, debonding along the bolt/rock interface and loss of the face plate, are available in the analysis procedure. The performance of a typical conventional rock bolt (fully grouted rebar) and a typical energy-absorbing rock bolt (D-bolt) under the scenarios of suspending loosened blocks and rock dilation is investigated using the proposed model. The reliability of the proposed model is verified by comparing the simulation results with theoretical predictions and experimental observations. The proposed model could be used to reveal the mechanism of each type of rock bolt in realistic scenarios and to provide a numerical way for presenting the detailed profile about the behavior of bolts, in particular at intermediate loading stages.

Simulation and experiment for depth sizing of cracks in anchor bolts by ultrasonic phased array technology

NASA Astrophysics Data System (ADS)

Lin, Shan

2018-04-01

There have been lots of reports about the occurrence of cracks in bolts in aging nuclear and thermal power plants. Sizing of such cracks is crucial for assessing the integrity of bolts. Currently, hammering and visual tests are used to detect cracks in bolts. However, they are not applicable for sizing cracks. Although the tip diffraction method is well known as a crack sizing technique, reflection echoes from threads make it difficult to apply this technique to bolts. This paper addresses a method for depth sizing of cracks in bolts by means of ultrasonic phased array technology. Numerical results of wave propagation in bolts by the finite element method (FEM) shows that a peak associated within the vicinity of a crack tip can be observed in the curve of echo intensity versus refraction angle for deep cracks. The refraction angle with respect to this peak decreases as crack depth increases. Such numerical results are verified by experiments on bolt specimens that have electrical discharge machining notches or fatigue cracks with different depths. In the experiment, a 10-MHz linear array probe is used. Depth of cracks in bolts using the refraction angle associated with the peak is determined and compared to actual depths. The comparison shows that accurately determining a crack depth from the inspection results is possible.

Automatic, computerized testing of bolts

NASA Technical Reports Server (NTRS)

Carlucci, J., Jr.; Lobb, V. B.; Stoller, F. W.

1970-01-01

System for testing bolts with various platings, lubricants, nuts, and tightening procedures tests 200 fasteners, and processes and summarizes the results, within one month. System measures input torque, nut rotation, bolt clamping force, bolt shank twist, and bolt elongation, data is printed in report form. Test apparatus is described.

Step test performance and risk of stress fractures among female army trainees.

PubMed

Cowan, David N; Bedno, Sheryl A; Urban, Nadia; Lee, Dara S; Niebuhr, David W

2012-06-01

Stress fractures and other musculoskeletal injuries are major sources of morbidity among female military trainees. Several risk factors have been postulated, particularly pre-existing fitness, usually assessed with post-entry run time for ≥ 1.0 mile. Physical fitness is not formally evaluated prior to Army entry. If a valid and simple test that identified women at increased risk of stress fracture were available and could be applied prior to entry, it would facilitate cost-benefit studies of deferral or interventions. These analyses were undertaken to determine if a 5-minute step test conducted before entry identified women at increased risk. A prospective study was conducted of weight-qualified women entering the Army in 2005-2006, with analyses completed in 2011. At the pre-entry examination, information was collected on age, BMI, smoking, race, and activity level. Everyone took the step test. All outpatient medical encounters were captured, and stress fractures and other musculoskeletal injuries identified. Women with stress fractures and those with other musculoskeletal injuries were evaluated separately. 1568 women were included in the study; 109 developed stress fractures and 803 other musculoskeletal injury. Women who failed the step test had a 76% higher stress fracture incidence and a 35% higher incidence of other musculoskeletal injuries. There was effect modification between age and test failure for stress fracture. A step test that can be administered before military entry identifies women with increased incidence of stress fracture and other musculoskeletal injury. This test could be used pre-entry to defer or target high-risk recruits for tailored fitness training before or after military entrance. Copyright © 2012 American Journal of Preventive Medicine. All rights reserved.

Fixtures Hold Nuts During Tightening Of Bolts

NASA Technical Reports Server (NTRS)

Gyekenyesi, John Z.

1993-01-01

Two fixtures designed for use on cross-head of tensile testing machine simplify adjustments of crosshead to accommodate specimens of various lengths. Two cagelike fixtures hold pairs of nuts, preventing nuts from turning while bolts are tightened. Enable one person acting alone to tighten bolts.

Nondestructive test method accurately sorts mixed bolts

NASA Technical Reports Server (NTRS)

Dezeih, C. J.

1966-01-01

Neutron activation analysis method sorts copper plated steel bolts from nickel plated steel bolts. Copper and nickel plated steel bolt specimens of the same configuration are irradiated with thermal neutrons in a test reactor for a short time. After thermal neutron irradiation, the bolts are analyzed using scintillation energy readout equipment.

Analysis of alternatives for using cable bolts as primary support at two low-seam coal mines

PubMed Central

Esterhuizen, Gabriel S.; Tulu, Ihsan B.

2016-01-01

Cable bolts are sometimes used in low-seam coal mines to provide support in difficult ground conditions. This paper describes cable bolting solutions at two low-seam coal mines in similar ground conditions. Both mines used support systems incorporating cable bolts as part of the primary support system. Two original cable bolt based support systems as well as two modified systems are evaluated to estimate their ability to prevent large roof falls. One of the support systems incorporated passive cable bolts, while the other used pre-tensioned cable bolts. The results and experience at the mines showed that the modified systems provided improved stability over the original support systems. The presence of the cable bolts is the most important contribution to stability against large roof falls, rather than the details of the support pattern. It was also found that a heavy steel channel can improve the safety of the system because of the ‘sling’ action it provides. Additionally, the analysis showed that fully-grouted rebar bolts load much earlier than the cable bolts, and pre-tensioning of the cable bolts can result in a more uniform distribution of loading in the roof. PMID:27722019

Application of Long Expansion Rock Bolt Support in the Underground Mines of Legnica-Głogów Copper District

NASA Astrophysics Data System (ADS)

Skrzypkowski, Krzysztof; Korzeniowski, Waldemar; Zagórski, Krzysztof; Dudek, Piotr

2017-09-01

In the underground mines of the Legnica-Głogów Copper District (LGOM) the main way to protect the room excavation is the use of a rock bolt support. For many years, it has proven to be an efficient security measure in excavations which met all safety standards and requirements. The article presents the consumption of the rock bolt support in the Mining Department "Polkowice-Sieroszowice" in the years 2010-2015 as well as the number of bolt supports that were used to secure the excavations. In addition, it shows the percentage of bolt supports that were used to conduct rebuilding work and cover the surface of exposed roofs. One of the factors contributing to the loss of the functionality of bolt supports is corrosion whose occurrence may lead directly to a reduction in the diameter of rock bolt support parts, in particular rods, bearing plates and nuts. The phenomenon of the corrosion of the bolt support and its elements in underground mining is an extremely common phenomenon due to the favorable conditions for its development in mines, namely high temperature and humidity, as well as the presence of highly aggressive water. This involves primarily a decrease in the capacity of bolt support construction, which entails the need for its strengthening, and often the need to perform the reconstruction of the excavation. The article presents an alternative for steel bearing plates, namely plates made using the spatial 3D printing technology. Prototype bearing plates were printed on a 3D printer Formiga P100 using the "Precymit" material. The used printing technology was SLS (Selective Laser Sintering), which is one of the most widely used technologies among all the methods of 3D printing for the short series production of the technical parts of the final product. The article presents the stress-strain characteristic of the long expansion connected rock bolt support OB25 with a length of 3.65 m. A rock bolt support longer than 2.6 m is an additional bolt support in excavations, and it is increasingly frequently used to reinforce roofs and in rebuilding the underground mines of KGHM Polish Copper S.A. In order to conduct the laboratory tests that are most suitable for the mine conditions, and yet are carried out on a laboratory test facility, the Authors used a steel cylinder with an external diameter of 102 mm and a length of 600 mm, which was filled with a core of rock (dolomite) from the roofs of the mine workings. In addition the maximum load that took over the bolt support made of rods and connected with sleeves was determined. For the initial tension, the elastic and plastic range of the maximal displacements, which were measured by the rope encoder, were determined. The statical tests of the expansion rock bolt support were carried out at the laboratory of the Department of Underground Mining in simulated mine conditions. The test facility enables the study of the long bolt rods on a geometric scale of 1:1 for the different ways of fixing. The aim of the laboratory research was to obtain the stress-strain characteristics, of the long expansion rock bolt support with a steel bearing plate and a plate printed on a 3D printer.

Evaluation of bolted connections in wood-plastic composites

NASA Astrophysics Data System (ADS)

Arnandha, Yudhi; Satyarno, Iman; Awaludin, Ali; Irawati, Inggar Septia; Ihsan, Muhamad; Wijanarko, Felyx Biondy; William, Mahdinur, Fardhani, Arfiati

2017-03-01

Wood-plastic composite (WPC) is a relatively new material that consists of sawdust and plastic polymer using the extrusion process. Due to its attributes such as low water content, low maintenance, UV durability and being fungi and termite resistant. Nowadays, WPC has already been produced in Indonesia using sawdust from local wood such as Albizia (Paraserianthes falcataria) and Teak (Tectona grandis). Moreover preliminary studies about the physical and mechanical WPC board from Albizia sawdust and HDPE plastic have been carried out. Based on these studies, WPC has a high shear strength around 25-30 MPa higher than its original wood shear strength. This paper was a part of the research in evaluating WPC as potential sheathing in a shear wall system. Since still little is known about connection behavior in WPC using Indonesian local wood, this study evaluated the connection for both of these two types of wood-plastic composite. WPC board from Albizia sawdust will be projected as shear wall sheathing and WPC stud from Teak sawdust projected to be shear wall frame. For this study, the embedding strength for both WPC was determined according to ASTM D 5764 standard, using two types of bolts (stainless bolt and standard bolt) with several diameters as variation (6 mm, 8 mm, 10 and 12 mm). Hence, dowel-bearing test under fastened condition conducted accordance to ASTM D5652, hereby the yield strength then compared with the prediction yield strength from European Yield Model (EYM). According to both single and double shear connection, it can be concluded that yield strength from the EYM method tended to under-predict the 5% diameter offset yield than the actual yield strength from the test. The yield strength itself increase with the increase of bolt diameter. For single shear connection, the highest yield strength was 12 mm standard bolt around 9732 N, slightly higher than stainless bolt around 9393 N. Whereby for double shear connection, the highest yield strength was 12 mm standard bolt around 12009 N, slightly higher than stainless bolt around 12009 N. Using statistical approach ANOVA, the different type of bolt between stainless bolt and standard bolt gave an insignificant result. Both type of bolt can be used as structural connection, moreover it was recommended using a stainless bolt for outdoor purpose to reduce corrosion.

Research on assessment of bolted joint state using elastic wave propagation

NASA Astrophysics Data System (ADS)

Kędra, R.; Rucka, M.

2015-07-01

The work contains results of experimental investigation of elastic wave propagation in a bolted single-lap joint. Tests were carried out for the excitation perpendicular to the connection plane. In experimental studies, PZT transducers were used for both excitation and registration of ultrasonic waves. The analyses took into account varying contact conditions between the elements of the connection depending on the value of the prestressing force. The influence of loosening/tightening of bolts on the energy dissipation was analysed. The experimental results proved the influence of bolt torque on quantitative characteristics of the signals. To improve the diagnostic possibilities only the initial parts of signals were analysed.

Easing The Calculation Of Bolt-Circle Coordinates

NASA Technical Reports Server (NTRS)

Burley, Richard K.

1995-01-01

Bolt Circle Calculation (BOLT-CALC) computer program used to reduce significant time consumed in manually computing trigonometry of rectangular Cartesian coordinates of holes in bolt circle as shown on blueprint or drawing. Eliminates risk of computational errors, particularly in cases involving many holes or in cases in which coordinates expressed to many significant digits. Program assists in many practical situations arising in machine shops. Written in BASIC. Also successfully compiled and implemented by use of Microsoft's QuickBasic v4.0.

The bolt on Space Shuttle Atlantis is source of concern

NASA Technical Reports Server (NTRS)

2000-01-01

A bolt is shown in the lower central part of the photo. It is visible as a dark circle with a shadow surrounding it inside a larger silvery circle. The bolt extends above the surface 2-1/4 inches, causing the shadow. The photo was taken at launch of Space Shuttle Atlantis on mission STS-106.

Releasable locking mechanisms

NASA Technical Reports Server (NTRS)

Ahmed, Rafiq (Inventor); Wingate, Robert J. (Inventor)

2005-01-01

In the aerospace field spacecraft components are held together by separation systems until a specific time when they must be separated or deployed. Customarily a threaded joining bolt engages one of the components to be joined, and a threaded nut is placed on that bolt against the other component so they can be drawn together by a releasable locking assembly. The releasable locking assembly herein includes a plunger having one end coupled to one end of a plunger bolt. The other end is flanged to abut and compress a coil spring when the plunger is advanced toward the interface plane between the two components. When the plunger is so advanced toward the interface plane, the end of the plunger bolt can be connected to the joining bolt. Thus during retraction the joining bolt is drawn to one side of the interface plane by the force of the expanding spring.

Releasable Locking Mechanisms

NASA Technical Reports Server (NTRS)

Ahmed, Rafiq (Inventor); Wingate, Robert J. (Inventor)

2005-01-01

In the aerospace field spacecraft components are held together by separation systems until a specific time when they must be separated or deployed. Customarily a threaded joining bolt engages one of the components to be joined, and a threaded nut is placed on that bolt against the other component so they can be drawn together by a releasable locking assembly. The releasable locking assembly herein includes a plunger having one end coupled to one end of a plunger bolt. The other end is flanged to abut and compress a coil spring when the plunger is advanced toward the interface plane between the two components. When the plunger is so advanced toward the interface plane, the end of the plunger bolt can be connected to the joining bolt. Thus during retraction the joining bolt is drawn to one side of the interface plane by the force of the expanding spring.

49 CFR 571.209 - Standard No. 209; Seat belt assemblies.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... (1) Eye bolts, shoulder bolts, or other bolt used to secure the pelvic restraint of seat belt... connecting webbing to an eye bolt shall be provided with a retaining latch or keeper which shall not move...) Single attachment hook for connecting webbing to any eye bolt shall be tested in the following manner...

A Foil Thrust Bearing Test Rig for Evaluation of High Temperature Performance and Durability

DTIC Science & Technology

2008-04-01

composed of similar elements used in journal bearings, but are designed to support a shaft axially. Often, discrete compliant pads are attached... shaft designed to mate with a test thrust runner. The runner is mounted to the shaft with four high strength bolts, and an interference fit ensures...attached to the drive is able to stop the spindle quickly through dynamic braking of the shaft rotational energy. This spindle arrangement has

77 FR 40828 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-11

... certain main landing gear (MLG) upper torque link bolts is reduced significantly due to incorrect fabrication. This proposed AD would require replacing certain MLG upper torque link bolts with a new or... safe life limit on certain MLG upper torque link bolts is reduced significantly due to incorrect...

Mechanics of Re-Torquing in Bolted Flange Connections

NASA Technical Reports Server (NTRS)

Gordon, Ali P.; Drilling Brian; Weichman, Kyle; Kammerer, Catherine; Baldwin, Frank

2010-01-01

It has been widely accepted that the phenomenon of time-dependent loosening of flange connections is a strong consequence of the viscous nature of the compression seal material. Characterizing the coupled interaction between gasket creep and elastic bolt stiffness has been useful in predicting conditions that facilitate leakage. Prior advances on this sub-class of bolted joints has lead to the development of (1) constitutive models for elastomerics, (2) initial tightening strategies, (3) etc. The effect of re-torque, which is a major consideration for typical bolted flange seals used on the Space Shuttle fleet, has not been fully characterized, however. The current study presents a systematic approach to characterizing bolted joint behavior as the consequence of sequentially applied torques. Based on exprimenta1 and numerical results, the optimal re-torquing parameters have been identified that allow for the negligible load loss after pre-load application

Feasibility of fiberglass-reinforced bolted wood connections

Treesearch

D. F. Windorski; L. A. Soltis; R. J. Ross

Bolted connections often fail by a shear plug or a splitting beneath the bolt caused by tension perpendicular-to-grain stresses as the bolt wedges its way through the wood. Preventing this type of failure would enhance the capacity and reliability of the bolted connection, thus increasing the overall integrity of a timber structure and enabling wood to compete...

21 CFR 137.280 - Bolted yellow corn meal.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that cleaned...

21 CFR 137.280 - Bolted yellow corn meal.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that cleaned...

Epigenomics and bolting tolerance in sugar beet genotypes.

PubMed

Hébrard, Claire; Peterson, Daniel G; Willems, Glenda; Delaunay, Alain; Jesson, Béline; Lefèbvre, Marc; Barnes, Steve; Maury, Stéphane

2016-01-01

In sugar beet (Beta vulgaris altissima), bolting tolerance is an essential agronomic trait reflecting the bolting response of genotypes after vernalization. Genes involved in induction of sugar beet bolting have now been identified, and evidence suggests that epigenetic factors are involved in their control. Indeed, the time course and amplitude of DNA methylation variations in the shoot apical meristem have been shown to be critical in inducing sugar beet bolting, and a few functional targets of DNA methylation during vernalization have been identified. However, molecular mechanisms controlling bolting tolerance levels among genotypes are still poorly understood. Here, gene expression and DNA methylation profiles were compared in shoot apical meristems of three bolting-resistant and three bolting-sensitive genotypes after vernalization. Using Cot fractionation followed by 454 sequencing of the isolated low-copy DNA, 6231 contigs were obtained that were used along with public sugar beet DNA sequences to design custom Agilent microarrays for expression (56k) and methylation (244k) analyses. A total of 169 differentially expressed genes and 111 differentially methylated regions were identified between resistant and sensitive vernalized genotypes. Fourteen sequences were both differentially expressed and differentially methylated, with a negative correlation between their methylation and expression levels. Genes involved in cold perception, phytohormone signalling, and flowering induction were over-represented and collectively represent an integrative gene network from environmental perception to bolting induction. Altogether, the data suggest that the genotype-dependent control of DNA methylation and expression of an integrative gene network participate in bolting tolerance in sugar beet, opening up perspectives for crop improvement. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Experimental studies on the effects of bolt parameters on the bearing characteristics of reinforced rock.

PubMed

Cheng, Liang; Zhang, Yidong; Ji, Ming; Zhang, Kai; Zhang, Minglei

2016-01-01

Roadways supported by bolts contain support structures that are built into the rock surrounding the roadway, referred to as reinforced rocks in this paper. Using physical model simulation, the paper investigates the bearing characteristics of the reinforced rock under different bolt parameters with incrementally increased load. The experimental results show that the stress at the measurement point inside the structure varies with the kinetic pressure. The stress increases slowly as the load is initially applied, displays accelerated growth in the middle of the loading application, and decreases or remains constant in the later stage of the loading application. The change in displacement of the surrounding rock exhibits the following characteristics: a slow increase when the load is first applied, accelerated growth in the middle stage, and violent growth in the later stage. There is a good correlation between the change in the measured stress and the change in the surrounding rock displacement. Increasing the density of the bolt support and the length and diameter of the bolt improves the load-bearing performance of the reinforced rock, including its strength, internal peak stress, and residual stress. Bolting improves the internal structure of the surrounding rocks, and the deterioration of the surrounding rock decreases with the distance between the bolt supports.

Bolt failure detection

DOEpatents

Sutton, Jr., Harry G.

1984-01-01

Bolts of a liquid metal fast breeder reactor, each bolt provided with an internal chamber filled with a specific, unique radioactive tag gas. Detection of the tag gas is indicative of a crack in an identifiable bolt.

Bolted-connection design

Treesearch

Lawrence A. Soltis; Thomas Lee Wilkinson

1987-01-01

Recent failures of bolted connections have raised doubts about our knowledge of their design. Some of the design criteria are based on research conducted more than 50 years ago. This paper compares results found in the literature, using the European Yield Theory as a basis of comparison, to summarize what is known about bolted-connection design and what needs further...

Multiple-bolted joints in wood members : a literature review

Treesearch

Peter James Moss

1997-01-01

This study reviewed the literature on experimental and analytical research for the connection of wood members using multiple laterally loaded bolts. From this, the influence of geometric factors were ascertained, such as staggered and aligned fasteners, optimum fastener configurations, row factors and length-to-diameter bolt ratios, spacing, end and edge distances, and...

A new diagnostic method of bolt loosening detection for thermal protection systems

NASA Astrophysics Data System (ADS)

Xie, Weihua; Meng, Songhe; Han, Jiecai; Du, Shanyi; Zhang, Boming; Yu, Dong

2009-07-01

Research and development efforts are underway to provide structural health monitoring systems to ensure the integrity of thermal protection system (TPS). An improved analytical method was proposed to assess the fastener integrity of a bolted structure in this paper. A new unsymmetrical washer was designed and fabricated, taking full advantage of piezoelectric ceramics (PZT) to play both roles as actuators and sensors, and using energy as the only extracted feature to identify abnormality. This diagnostic method is not restricted by the materials of the bracket, panel and base structure of the TPS whose condition is under inspection. A series of experiments on a metallic honeycomb sandwich panel were completed to demonstrate the capability of detecting bolt loosening on the TPS structure. Studies showed that this method can be used not only to identify the location of loosened bolts rapidly, but also to estimate the torque level of loosening bolts. Since that energy is the only extracted feature used to detect bolt loosening in this method, the diagnostic process become very simple and swift without sacrificing the accuracy of the results.

Quick-Connect, Slow-Disconnect Bolt

NASA Technical Reports Server (NTRS)

Weddendorf, Bruce

1995-01-01

Proposed bolt functions similarly to device described in article "Quick-Connect, Slow-Disconnect Nut" (MFS-28833). Bolt installed in standard threaded hole simply by pushing it into hole. Once inserted, bolt withdrawn only by turning it in conventional way.

Bolt installation tool for tightening large nuts and bolts

NASA Technical Reports Server (NTRS)

Mcdougal, A. R.; Norman, R. M.

1974-01-01

Large bolts and nuts are accurately tightened to structures without damaging torque stresses. There are two models of bolt installation tool. One is rigidly mounted and one is hand held. Each model includes torque-multiplier unit.

Evaluation of Rock Bolt Support for Polish Hard Rock Mines

NASA Astrophysics Data System (ADS)

Skrzypkowski, Krzysztof

2018-03-01

The article presents different types of rock bolt support used in Polish ore mining. Individual point resin and expansion rock bolt support were characterized. The roof classes for zinc and lead and copper ore mines were presented. Furthermore, in the article laboratory tests of point resin rock bolt support in a geometric scale of 1:1 with minimal fixing length of 0.6 m were made. Static testing of point resin rock bolt support were carried out on a laboratory test facility of Department of Underground Mining which simulate mine conditions for Polish ore and hard coal mining. Laboratory tests of point resin bolts were carried out, especially for the ZGH Bolesław, zinc and lead "Olkusz - Pomorzany" mine. The primary aim of the research was to check whether at the anchoring point length of 0.6 m by means of one and a half resin cartridge, the type bolt "Olkusz - 20A" is able to overcome the load.The second purpose of the study was to obtain load - displacement characteristic with determination of the elastic and plastic range of the bolt. For the best simulation of mine conditions the station steel cylinders with an external diameter of 0.1 m and a length of 0.6 m with a core of rock from the roof of the underground excavations were used.

Experiments in Aligning Threaded Parts Using a Robot Hand

NASA Technical Reports Server (NTRS)

Diftler, M. A.; Walker, I. D.

1999-01-01

Techniques for determining and correcting threaded part alignment using force and angular position data are developed to augment currently limited techniques for align- ing threaded parts. These new techniques are based on backspinning a nut with respect to a bolt and measuring the force change that occurs when the bolt "falls" into the nut. Kinematic models that describe the relationship between threaded parts during backspinning are introduced and are used to show how angular alignment may be determined. The models indicate how to distinguish between the aligned and misaligned cases of a bolt and a nut connection by using axial force data only. In addition, by tracking the in-plane relative attitude of the bolt during spinning, data can be obtained on the direction of the angular misalignment which, in turn, is used to correct the misalignment. Results from experiments using a bolt held in a specialized fixture and a three fingers Stanford/JPL hand are presented.

Zero torque gear head wrench

NASA Technical Reports Server (NTRS)

Mcdougal, A. R.; Norman, R. M. (Inventor)

1976-01-01

A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stress to bolt-receiving structures is introduced. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.

Inflorescence Development and the Role of LsFT in Regulating Bolting in Lettuce (Lactuca sativa L.).

PubMed

Chen, Zijing; Han, Yingyan; Ning, Kang; Ding, Yunyu; Zhao, Wensheng; Yan, Shuangshuang; Luo, Chen; Jiang, Xiaotang; Ge, Danfeng; Liu, Renyi; Wang, Qian; Zhang, Xiaolan

2017-01-01

Lettuce ( Lactuca sativa L.) is one of the most important leafy vegetable that is consumed during its vegetative growth. The transition from vegetative to reproductive growth is induced by high temperature, which has significant economic effect on lettuce production. However, the progression of floral transition and the molecular regulation of bolting are largely unknown. Here we morphologically characterized the inflorescence development and functionally analyzed the FLOWERING LOCUS T (LsFT) gene during bolting regulation in lettuce. We described the eight developmental stages during floral transition process. The expression of LsFT was negatively correlated with bolting in different lettuce varieties, and was promoted by heat treatment. Overexpression of LsFT could recover the late-flowering phenotype of ft-2 mutant. Knockdown of LsFT by RNA interference dramatically delayed bolting in lettuce, and failed to respond to high temperature. Therefore, this study dissects the process of inflorescence development and characterizes the role of LsFT in bolting regulation in lettuce.

Inflorescence Development and the Role of LsFT in Regulating Bolting in Lettuce (Lactuca sativa L.)

PubMed Central

Chen, Zijing; Han, Yingyan; Ning, Kang; Ding, Yunyu; Zhao, Wensheng; Yan, Shuangshuang; Luo, Chen; Jiang, Xiaotang; Ge, Danfeng; Liu, Renyi; Wang, Qian; Zhang, Xiaolan

2018-01-01

Lettuce (Lactuca sativa L.) is one of the most important leafy vegetable that is consumed during its vegetative growth. The transition from vegetative to reproductive growth is induced by high temperature, which has significant economic effect on lettuce production. However, the progression of floral transition and the molecular regulation of bolting are largely unknown. Here we morphologically characterized the inflorescence development and functionally analyzed the FLOWERING LOCUS T (LsFT) gene during bolting regulation in lettuce. We described the eight developmental stages during floral transition process. The expression of LsFT was negatively correlated with bolting in different lettuce varieties, and was promoted by heat treatment. Overexpression of LsFT could recover the late-flowering phenotype of ft-2 mutant. Knockdown of LsFT by RNA interference dramatically delayed bolting in lettuce, and failed to respond to high temperature. Therefore, this study dissects the process of inflorescence development and characterizes the role of LsFT in bolting regulation in lettuce. PMID:29403510

Design and Evaluation of a Bolted Joint for a Discrete Carbon-Epoxy Rod-Reinforced Hat Section

NASA Technical Reports Server (NTRS)

Baker, Donald J.; Rousseau, Carl Q.

1996-01-01

The use of pre-fabricated pultruded carbon-epoxy rods has reduced the manufacturing complexity and costs of stiffened composite panels while increasing the damage tolerance of the panels. However, repairability of these highly efficient discrete stiffeners has been a concern. Design, analysis, and test results are presented in this paper for a bolted-joint repair for the pultruded rod concept that is capable of efficiently transferring axial loads in a hat-section stiffener on the upper skin segment of a heavily loaded aircraft wing component. A tension and a compression joint design were evaluated. The tension joint design achieved approximately 1.0 percent strain in the carbon-epoxy rod-reinforced hat-section and failed in a metal fitting at 166 percent of the design ultimate load. The compression joint design failed in the carbon-epoxy rod-reinforced hat-section test specimen area at approximately 0.7 percent strain and at 110 percent of the design ultimate load. This strain level of 0.7 percent in compression is similar to the failure strain observed in previously reported carbon-epoxy rod-reinforced hat-section column tests.

Mine roof driller-bolter apparatus and method

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

Hibbard, G.A.; Lumbra, R.C.; Morrison, W.D.

1983-12-13

An apparatus for bolting the roof of an underground mine is disclosed comprising a mobile frame, a boom extending from the frame and a housing provided at the end of the frame. The housing supports an upwardly extending stinger, a drilling mechanism including a drill centralizer having a central bore therethrough and a passageway in communication with the central bore, a device for delivering a container of roof bolting anchoring media through the passageway and through the drill centralizer and into a drilled hole, a device for indexing a roof bolt into alignment with the drilled hole and a spinnermore » for driving the roof bolt into the drilled hole. The present invention also provides a method for bolting the roof of an underground mine comprising the steps of stinging a housing against the roof of the mine, moving a drill centralizer into communication with the roof and drilling a hole in the roof. Without retracting the drill centralizer from communication with the roof, a container of roof bolt anchoring media is delivered through the centralizer and into the drilled hole. The drill centralizer is thereafter retracted and the housing is moved to align a roof bolt with a drilled hole. Then the roof bolt is driven into the drilled hole and the bolt anchoring media sets around the bolt.« less

Calculation and analysis on bolts on the slope of Xigeda soil

NASA Astrophysics Data System (ADS)

Wang, Wei; Chen, Wei; Long, Wei; Die, Jian

2018-03-01

In this paper, the commonly-used full-length bonded bolt in Xigeda soil and its slope support engineering is taken as the research object, applying the mechanical property indicator of Xigeda soil and two existing bolt load transmission mechanism and calculation theory, so that two calculation formulas of anchoring forces can be deduced, and verified by the experimental data. This paper has certain practical significance.

Effect of Temperature and Viscoelastic Creep on the Clamp-Up Load in Hybrid Composite/Metal Bolted Joints

DTIC Science & Technology

2009-08-17

aluminum bolted to aluminum specimens. 2. Similarly to the temperature effects on the response of the specimens tested, relative humidity swings have a...bolted to aluminum specimens show the highest susceptibility to relative humidity shifts. This response is believed to be related to their ability to...relaxation stage, little effects are detected from relative humidity fluctuations. 81 9. The data

Drag and Cooling Tests in the 24 ft Wind Tunnel on a Centaurus-Buckingham Wing Nacelle Installation. Part 3. Tests with High Speed Cowl Entry (Tempest Type)

DTIC Science & Technology

1946-07-01

ESTABLISHMENT Farnboruugh. Hants. DRAG AND COOLING TESTS IN THE 24 ft. WIND TUNNEL ON A ^ CENTAURUS -BUCKINGHAM WING NACELLE INSTALLATION PART...ILLIETUATICNS Ccntaurus-f uckinghain nacelle inst -illation with high entry velocity cowl ^soolii» ; fan not fitted. Installation of Centaurus .inline

Damage Progression in Bolted Composites

NASA Technical Reports Server (NTRS)

Minnetyan, Levon; Chamis, Christos C.; Gotsis, Pascal K.

1998-01-01

Structural durability, damage tolerance, and progressive fracture characteristics of bolted graphite/epoxy composite laminates are evaluated via computational simulation. Constituent material properties and stress and strain limits are scaled up to the structure level to evaluate the overall damage and fracture propagation for bolted composites. Single and double bolted composite specimens with various widths and bolt spacings are evaluated. The effect of bolt spacing is investigated with regard to the structural durability of a bolted joint. Damage initiation, growth, accumulation, and propagation to fracture are included in the simulations. Results show the damage progression sequence and structural fracture resistance during different degradation stages. A procedure is outlined for the use of computational simulation data in the assessment of damage tolerance, determination of sensitive parameters affecting fracture, and interpretation of experimental results with insight for design decisions.

Damage Progression in Bolted Composites

NASA Technical Reports Server (NTRS)

Minnetyan, Levon; Chamis, Christos; Gotsis, Pascal K.

1998-01-01

Structural durability,damage tolerance,and progressive fracture characteristics of bolted graphite/epoxy composite laminates are evaluated via computational simulation. Constituent material properties and stress and strain limits are scaled up to the structure level to evaluate the overall damage and fracture propagation for bolted composites. Single and double bolted composite specimens with various widths and bolt spacings are evaluated. The effect of bolt spacing is investigated with regard to the structural durability of a bolted joint. Damage initiation, growth, accumulation, and propagation to fracture are included in the simulations. Results show the damage progression sequence and structural fracture resistance during different degradation stages. A procedure is outlined for the use of computational simulation data in the assessment of damage tolerance, determination of sensitive parameters affecting fracture, and interpretation of experimental results with insight for design decisions.

Reducing Bolt Preload Variation with Angle-of-Twist Bolt Loading

NASA Technical Reports Server (NTRS)

Thompson, Bryce; Nayate, Pramod; Smith, Doug; McCool, Alex (Technical Monitor)

2001-01-01

Critical high-pressure sealing joints on the Space Shuttle reusable solid rocket motor require precise control of bolt preload to ensure proper joint function. As the reusable solid rocket motor experiences rapid internal pressurization, correct bolt preloads maintain the sealing capability and structural integrity of the hardware. The angle-of-twist process provides the right combination of preload accuracy, reliability, process control, and assembly-friendly design. It improves significantly over previous methods. The sophisticated angle-of-twist process controls have yielded answers to all discrepancies encountered while the simplicity of the root process has assured joint preload reliability.

Construction method of pre assembled unit of bolt sphere grid

NASA Astrophysics Data System (ADS)

Hu, L. W.; Guo, F. L.; Wang, J. L.; Bu, F. M.

2018-03-01

The traditional construction of bolt sphere grid has many disadvantages, such as high cost, large amount of work at high altitude and long construction period, in order to make up for these shortcomings, in this paper, a new and applicable construction method is explored: setting up local scaffolding, installing the bolt sphere grid starting frame on the local scaffolding, then the pre assembled unit of bolt sphere grid is assembled on the ground, using small hoisting equipment to lift pre assembled unit to high altitude and install. Compared with the traditional installation method, the construction method has strong practicability and high economic efficiency, and has achieved good social and economic benefits.

Ultrasonic Method for Deployment Mechanism Bolt Element Preload Verification

NASA Technical Reports Server (NTRS)

Johnson, Eric C.; Kim, Yong M.; Morris, Fred A.; Mitchell, Joel; Pan, Robert B.

2014-01-01

Deployment mechanisms play a pivotal role in mission success. These mechanisms often incorporate bolt elements for which a preload within a specified range is essential for proper operation. A common practice is to torque these bolt elements to a specified value during installation. The resulting preload, however, can vary significantly with applied torque for a number of reasons. The goal of this effort was to investigate ultrasonic methods as an alternative for bolt preload verification in such deployment mechanisms. A family of non-explosive release mechanisms widely used by satellite manufacturers was chosen for the work. A willing contractor permitted measurements on a sampling of bolt elements for these release mechanisms that were installed by a technician following a standard practice. A variation of approximately 50% (+/- 25%) in the resultant preloads was observed. An alternative ultrasonic method to set the preloads was then developed and calibration data was accumulated. The method was demonstrated on bolt elements installed in a fixture instrumented with a calibrated load cell and designed to mimic production practice. The ultrasonic method yielded results within +/- 3% of the load cell reading. The contractor has since adopted the alternative method for its future production. Introduction

Candidate Earth Entry Trajectories to Mimic Venus Aerocapture Using a Lifting ADEPT

NASA Technical Reports Server (NTRS)

Williams, Jimmy

2017-01-01

A Lifting ADEPT is considered for aerocapture at Venus. Analysis concerning the heating environment leads to an initial sizing estimate. In tandem, a direct entry profile at Earth is considered to act as a facsimile for the Venus aerocapture heating environment. The bounds of this direct entry profile are determined and it is found that a trajectory from a Geostationary Transfer Orbit with a Lifting ADEPT capable of fitting on a rideshare opportunity is capable of matching certain aspects of this heating environment.

MADS-Box Genes and Gibberellins Regulate Bolting in Lettuce (Lactuca sativa L.)

PubMed Central

Han, Yingyan; Chen, Zijing; Lv, Shanshan; Ning, Kang; Ji, Xueliang; Liu, Xueying; Wang, Qian; Liu, Renyi; Fan, Shuangxi; Zhang, Xiaolan

2016-01-01

Bolting in lettuce is promoted by high temperature and bolting resistance is of great economic importance for lettuce production. But how bolting is regulated at the molecular level remains elusive. Here, a bolting resistant line S24 and a bolting sensitive line S39 were selected for morphological, physiological, transcriptomic and proteomic comparisons. A total of 12204 genes were differentially expressed in S39 vs. S24. Line S39 was featured with larger leaves, higher levels of chlorophyll, soluble sugar, anthocyanin and auxin, consistent with its up-regulation of genes implicated in photosynthesis, oxidation-reduction and auxin actions. Proteomic analysis identified 30 differentially accumulated proteins in lines S39 and S24 upon heat treatment, and 19 out of the 30 genes showed differential expression in the RNA-Seq data. Exogenous gibberellins (GA) treatment promoted bolting in both S39 and S24, while 12 flowering promoting MADS-box genes were specifically induced in line S39, suggesting that although GA regulates bolting in lettuce, it may be the MADS-box genes, not GA, that plays a major role in differing the bolting resistance between these two lettuce lines. PMID:28018414

Sleeve expansion of bolt holes in railroad rail. volume III - field experiment results

DOT National Transportation Integrated Search

1998-02-01

The bolt-hole cold-expansion process has been demonstrated by laboratory tests to significantly affect the initiation and propagation of fatigue cracks from rail bolt holes such that a reduction of the incidence of rail-bolt-holde failure in cold-exp...

Laboratory testing of a long expansion rock bolt support for energy-absorbing applications

NASA Astrophysics Data System (ADS)

Skrzypkowski, Krzysztof

2018-01-01

The main purpose of rock support and reinforcement in underground mining is to maintain excavations safe and open for their intended lifespan. The basic type of rock mass reinforcement method both in ore and hard coal mining is rock bolt support. Very often, existing bolt support systems are not always capable of providing a reliable controlled performance. Therefore, in recent years energy-absorbing bolts which are exposed to dynamic loading, for example from rock burst caused by high rock stresses, earthquakes, or blasting have appeared. In this article particular attention was paid to short and long expansion bolts. Quasi-static tests of expansion bolts were carried out at the laboratory test facility in simulated mining conditions, especially for the KGHM Polska Miedź S.A. mines. In the underground mines of the Legnica-Głogów Copper District (LGOM) the main way to protect the room excavation is rock bolt support with a length from 1.2 m to 2.6 m. Rock bolt support longer than 2.6 m is considered as additional support of excavations and is increasingly being used to reinforce the roofs. The comparisons of energy-absorbing short and long expansion bolts with a length of 1.8m, 3.6m and 5.2m were presented. In addition, for elastic and plastic range of each bolts were determined.

Curve fits of predicted inviscid stagnation-point radiative heating rates, cooling factors, and shock standoff distances for hyperbolic earth entry

NASA Technical Reports Server (NTRS)

Suttles, J. T.; Sullivan, E. M.; Margolis, S. B.

1974-01-01

Curve-fit formulas are presented for the stagnation-point radiative heating rate, cooling factor, and shock standoff distance for inviscid flow over blunt bodies at conditions corresponding to high-speed earth entry. The data which were curve fitted were calculated by using a technique which utilizes a one-strip integral method and a detailed nongray radiation model to generate a radiatively coupled flow-field solution for air in chemical and local thermodynamic equilibrium. The range of free-stream parameters considered were altitudes from about 55 to 70 km and velocities from about 11 to 16 km.sec. Spherical bodies with nose radii from 30 to 450 cm and elliptical bodies with major-to-minor axis ratios of 2, 4, and 6 were treated. Powerlaw formulas are proposed and a least-squares logarithmic fit is used to evaluate the constants. It is shown that the data can be described in this manner with an average deviation of about 3 percent (or less) and a maximum deviation of about 10 percent (or less). The curve-fit formulas provide an effective and economic means for making preliminary design studies for situations involving high-speed earth entry.

Shear joint capability versus bolt clearance

NASA Technical Reports Server (NTRS)

Lee, H. M.

1992-01-01

The results of a conservative analysis approach into the determination of shear joint strength capability for typical space-flight hardware as a function of the bolt-hole clearance specified in the design are presented. These joints are comprised of high-strength steel fasteners and abutments constructed of aluminum alloys familiar to the aerospace industry. A general analytical expression was first arrived at which relates bolt-hole clearance to the bolt shear load required to place all joint fasteners into a shear transferring position. Extension of this work allowed the analytical development of joint load capability as a function of the number of fasteners, shear strength of the bolt, bolt-hole clearance, and the desired factor of safety. Analysis results clearly indicate that a typical space-flight hardware joint can withstand significant loading when less than ideal bolt hole clearances are used in the design.

Discussion about effecting of stiffener in four bolts in a row end plate connection for long span and heavy load steel structures in Vietnam

NASA Astrophysics Data System (ADS)

Huong, Khang T.; Nguyen, Cung H.

2018-04-01

Nowadays, steel structure industry in Vietnam is in strong development. The construction of steel structure becomes larger span and heavier load. The issue spawned a number of issues arise from optimizing connections. Typical of steel connections in prefabricated steel structure that is an end plate (face plate) bolted connection. When the connection carried a heavy load, then the number of bolts is required much more. Increasing the number of rows bolts will less effective because can still not enough strength requirements, the bolts in row near rotational center will level arm reduction, then it cannot carry heavy loads. The current solution is doing multiple bolts in a row. Current standards such as EN [1], AISC [2] are no specific guidelines for calculating the connection four bolts in a row that primarily assumes the way works like a T-stub of the two bolts a row. Some articles studied T-stub four bolts in a row [3], [4], [5], [6] by component method but it has some components which weren’t considered. In this paper, in order to provide a contribution to improve the T-stub four bolts in a row, the stiffener component in T-stub will be added and compared with T-stub without stiffener by the finite element model to demonstrate effectiveness in reducing stress and displacement of T-stub. It gives ideas for the economic design of four bolts in a row end plate connection in Vietnam for future.

Sleeve Expansion of Bolt Holes in Railroad Rail : Volume I, Description and Planning

DOT National Transportation Integrated Search

1980-02-01

The most predominant failure mode of rails with bolt joints is a web crack initiating at the rail bolt hole. This failure mode is of a classical fatigue nature induced by web stress concentration around the bolt hole. This program was conducted to ap...

30 CFR 75.204 - Roof bolting.

Code of Federal Regulations, 2014 CFR

2014-07-01

... would not anchor in competent strata, corrective action shall be taken. (3) The installed torque or.... (4) In each roof bolting cycle, the actual torque or tension of the first tensioned roof bolt... drill head used, at least one roof bolt out of every four installed shall be measured for actual torque...

Random Vibration and Torque Tests of Fasteners Secured With Locking Cable, Room Temperature Vulcanized (RTV) Rubber, and Closed Cell Foam to Support the Launch of STS-82

NASA Technical Reports Server (NTRS)

Yost, V. H.

1997-01-01

During a walkdown of the Space Transportation System (STS) orbiter for the 82nd Space Shuttle flight (STS-82), technicians found several safety cables for bolts with missing or loose ferrules. Typically, two or three bolts are secured with a cable which passes through one of the holes in the head of each bolt and a ferrule is crimped on each end of the cable to prevent it from coming out of the holes. The purpose of the cable is to prevent bolts from rotating should they become untightened. Other bolts are secured with either a locking cable or wire which is covered with RTV and foam. The RTV and foam would have to be removed to inspect for missing or loose ferrules. To determine whether this was necessary, vibration and torque test fixtures and tests were made to determine whether or not bolts with missing or loose ferrules would unloosen. These tests showed they would not, and the RTV and foam was not removed.

Survival of biofilm-forming Salmonella on stainless steel bolt threads under dry conditions.

PubMed

Morita, Yukio; Komoda, Emiko; Ono, Kazuaki; Kumagai, Susumu

2011-01-01

We examined the survival of two biofilm-forming strains and two biofilm-deficient strains of non typhoid Salmonella (NTS) on stainless steel bolt threads under dry conditions. Five µL of tryptone soya broth or egg yolke mulsion containing NTS strains at a concentration of 9 log cfu/mL was dropped onto the thread surfaces of hexagonal bolts. After inoculation, the bolts were screwed into the nuts, and then removed (Separate type) or not removed (Unit type). The two types of samples were kept in a dry environment (20.0-25.0°C, 2-15% humidity) and bacteria on the surfaces were periodically counted. Biofilm-forming strains were recovered from all samples after 336 days of incubation, but biofilm-deficient strains were isolated from only two of 8 samples after 336 days. This finding demonstrates that NTS can survive for approximately one year on bolt threads, providing direct evidence of the potential risk of constructions having crevices or uneven surfaces as possible contamination sources. The risk of cross-contamination may be higher for biofilm-forming strains than for biofilm-deficient strains.

Removable bearing arrangement for a wind turbine generator

DOEpatents

Bagepalli, Bharat Sampathkumaran; Jansen, Patrick Lee; Gadre, Aniruddha Dattatraya

2010-06-15

A wind generator having removable change-out bearings includes a rotor and a stator, locking bolts configured to lock the rotor and stator, a removable bearing sub-assembly having at least one shrunk-on bearing installed, and removable mounting bolts configured to engage the bearing sub-assembly and to allow the removable bearing sub-assembly to be removed when the removable mounting bolts are removed.

Method for changing removable bearing for a wind turbine generator

DOEpatents

Bagepalli, Bharat Sampathkumaran [Niskayuna, NY; Jansen, Patrick Lee , Gadre; Dattatraya, Aniruddha [Rexford, NY

2008-04-22

A wind generator having removable change-out bearings includes a rotor and a stator, locking bolts configured to lock the rotor and stator, a removable bearing sub-assembly having at least one shrunk-on bearing installed, and removable mounting bolts configured to engage the bearing sub-assembly and to allow the removable bearing sub-assembly to be removed when the removable mounting bolts are removed.

In Vivo fitness associated with high virulence in a vertebrate virus is a complex trait regulated by host entry, replication, and shedding

USGS Publications Warehouse

Wargo, Andrew R.; Kurath, Gael

2011-01-01

The relationship between pathogen fitness and virulence is typically examined by quantifying only one or two pathogen fitness traits. More specifically, it is regularly assumed that within-host replication, as a precursor to transmission, is the driving force behind virulence. In reality, many traits contribute to pathogen fitness, and each trait could drive the evolution of virulence in different ways. Here, we independently quantified four viral infection cycle traits, namely, host entry, within-host replication, within-host coinfection fitness, and shedding, in vivo, in the vertebrate virus Infectious hematopoietic necrosis virus (IHNV). We examined how each of these stages of the viral infection cycle contributes to the fitness of IHNV genotypes that differ in virulence in rainbow trout. This enabled us to determine how infection cycle fitness traits are independently associated with virulence. We found that viral fitness was independently regulated by each of the traits examined, with the largest impact on fitness being provided by within-host replication. Furthermore, the more virulent of the two genotypes of IHNV we used had advantages in all of the traits quantified. Our results are thus congruent with the assumption that virulence and within-host replication are correlated but suggest that infection cycle fitness is complex and that replication is not the only trait associated with virulence.

Removable Type Expansion Bolt Innovative Design

NASA Astrophysics Data System (ADS)

Wang, Feng-Lan; Zhang, Bo; Gao, Bo; Liu, Yan-Xin; Gao, Bo

2016-05-01

Expansion bolt is a kind of the most common things in our daily life. Currently, there are many kinds of expansion bolts in the market. However, they have some shortcomings that mainly contain underuse and unremovement but our innovation of design makes up for these shortcomings very well. Principle of working follows this: expansion tube is fixed outside of bolt, steel balls and expansion covers are fixed inside. Meanwhile, the steel balls have 120° with each other. When using it ,expansion cover is moved in the direction of its internal part. So the front part of expansion bolt cover is increasingly becoming big and steel halls is moved outside. Only in this way can it be fixed that steel balls make expansion tube expand. When removing them, expansion bolt is moved outside. So the front part of expansion bolt cover is gradually becoming small and steel balls moves inside, after expansion tube shrinks, we can detach them.

Bolted joints in graphite-epoxy composites

NASA Technical Reports Server (NTRS)

Hart-Smith, L. J.

1976-01-01

All-graphite/epoxy laminates and hybrid graphite-glass/epoxy laminates were tested. The tests encompassed a range of geometries for each laminate pattern to cover the three basic failure modes - net section tension failure through the bolt hole, bearing and shearout. Static tensile and compressive loads were applied. A constant bolt diameter of 6.35 mm (0.25 in.) was used in the tests. The interaction of stress concentrations associated with multi-row bolted joints was investigated by testing single- and double-row bolted joints and open-hole specimens in tension. For tension loading, linear interaction was found to exist between the bearing stress reacted at a given bolt hole and the remaining tension stress running by that hole to be reacted elsewhere. The interaction under compressive loading was found to be non-linear. Comparative tests were run using single-lap bolted joints and double-lap joints with pin connection. Both of these joint types exhibited lower strengths than were demonstrated by the corresponding double-lap joints. The analysis methods developed here for single bolt joints are shown to be capable of predicting the behavior of multi-row joints.

Relationship between locking-bolt torque and load pre-tension in the Ilizarov frame.

PubMed

Osei, N A; Bradley, B M; Culpan, P; Mitchell, J B; Barry, M; Tanner, K E

2006-10-01

The wire-bolt interface in an Ilizarov frame has been mechanically tested. The optimal torque to be applied to the frame locking-bolts during physiological loading has been defined. The set-up configuration was as is used clinically except a copper tube was used to simulate bone. The force-displacement curves of the Ilizarov wires are not altered by locking-bolt torque. The force in the bone model at which pre-tension is lost increases as the locking-bolts are tightened to 14 Nm torque, but decreases if torque exceeds 14 Nm. Thus, 14 Nm is the optimal locking-bolt torque in frame. The relationship between pre-tension versus load for different locking-bolt torques arises because at low and high clamping torques poor wire holding and plastic deformation respectively occur. Wire damage was seen under light and electron microscopy. Clinically, over or under-tightening locking-bolts will cause loss of pre-tension, reduction in frame stiffness and excessive movement at the fracture site, which may be associated with delayed union.

Failure mechanisms of laminates transversely loaded by bolt push-through

NASA Technical Reports Server (NTRS)

Waters, W. A., Jr.; Williams, J. G.

1985-01-01

Stiffened composite panels proposed for fuselage and wing design utilize a variety of stiffener-to-skin attachment concepts including mechanical fasteners. The attachment concept is an important factor influencing the panel's strength and can govern its performance following local damage. Mechanical fasteners can be an effective method for preventing stiffener-skin separation. One potential failure mode for bolted panels occurs when the bolts pull through the stiffener attachment flange or skin. The resulting loss of support by the skin to the stiffener and by the stiffener to the skin can result in local buckling and subsequent panel collapse. The characteristic failure modes associated with bolt push-through failure are described and the results of a parametric study of the effects that different material systems, boundary conditions, and laminates have on the forces and displacements required to cause damage and bolt pushthrough failure are presented.

Metal-to-ceramic attachment device

DOEpatents

Pavelka, Edwin A.; Grindstaff, Quirinus G.; Scheppele, Stuart E.

1985-01-01

A metal-to-ceramic fastening device is disclosed for securing a metal member to a ceramic member with respective confronting surfaces thereon clamped together, comprising a threaded bolt adapted to extend through a bolt hole in the metal member and into an aligned opening in the ceramic member, a rod nut threadedly receiving the bolt and adapted to span the opening in the ceramic member, and a pressure limiting member received on the bolt between the nut and the confronting surface of the metal member for limiting the movement of the nut toward the metal member when the bolt is tightened, so as to limit the pressure applied by the nut to the ceramic member to avoid damage thereto. The fastening device also prevents damage to the ceramic member due to thermal stresses. The pressure limiting member may have a shallow dish-shaped depression facing the rod nut to assist in accommodating thermal stresses.

Submillimeter bolt location in car bodywork for production line quality inspection

NASA Astrophysics Data System (ADS)

Altamirano-Robles, Leopoldo; Arias-Estrada, Miguel; Alviso-Quibrera, Samuel; Lopez-Lopez, Aurelio

2000-03-01

In the automotive industry, a vehicle begins with the construction of the vehicle floor. Later on, several robots weld a series of bolts to this floor which are used to fix other parts. Due to several problems, like welding tools wearing, robot miscalibration or momentary low power supply, among others, some bolts are incorrectly positioned or are not present at all, bringing problems and delays in the next work cells. Therefore, it is of importance to verify the quality of welded parts before the following assembly steps. A computer vision system is proposed in order to locate autonomously the presence and quality of the bolts. The system should carry on the inspection in real time at the car assembly line under the following conditions: without touching the bodywork, with a precision in the submillimeter range and in few seconds. In this paper we present a basic computer vision system for bolt location in the submillimeter range. We analyze three arrangements of the system components (camera and illumination sources) that produce different results in the localization. Results are presented and compared for the three approaches obtained under laboratory conditions. The algorithms were tested in the assembling line. Variations up to one millimeter in the welded position of the bolts were observed.

Analysis of the current rib support practices and techniques in U.S. coal mines

PubMed Central

Mohamed, Khaled M.; Murphy, Michael M.; Lawson, Heather E.; Klemetti, Ted

2016-01-01

Design of rib support systems in U.S. coal mines is based primarily on local practices and experience. A better understanding of current rib support practices in U.S. coal mines is crucial for developing a sound engineering rib support design tool. The objective of this paper is to analyze the current practices of rib control in U.S. coal mines. Twenty underground coal mines were studied representing various coal basins, coal seams, geology, loading conditions, and rib control strategies. The key findings are: (1) any rib design guideline or tool should take into account external rib support as well as internal bolting; (2) rib bolts on their own cannot contain rib spall, especially in soft ribs subjected to significant load—external rib control devices such as mesh are required in such cases to contain rib sloughing; (3) the majority of the studied mines follow the overburden depth and entry height thresholds recommended by the Program Information Bulletin 11-29 issued by the Mine Safety and Health Administration; (4) potential rib instability occurred when certain geological features prevailed—these include draw slate and/or bone coal near the rib/roof line, claystone partings, and soft coal bench overlain by rock strata; (5) 47% of the studied rib spall was classified as blocky—this could indicate a high potential of rib hazards; and (6) rib injury rates of the studied mines for the last three years emphasize the need for more rib control management for mines operating at overburden depths between 152.4 m and 304.8 m. PMID:27648341

33 CFR 156.130 - Connection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... material in joints and couplings to ensure a leak-free seal; (2) Use a bolt in at least every other hole... chapter; (3) Use a bolt in each hole in each temporary bolted connection that uses a flange other than one that meets ANSI standards; (4) Use a bolt in each hole of each permanently connected flange; (5) Use...

33 CFR 156.130 - Connection.

Code of Federal Regulations, 2011 CFR

2011-07-01

... material in joints and couplings to ensure a leak-free seal; (2) Use a bolt in at least every other hole... chapter; (3) Use a bolt in each hole in each temporary bolted connection that uses a flange other than one that meets ANSI standards; (4) Use a bolt in each hole of each permanently connected flange; (5) Use...

33 CFR 156.130 - Connection.

Code of Federal Regulations, 2014 CFR

2014-07-01

... material in joints and couplings to ensure a leak-free seal; (2) Use a bolt in at least every other hole... chapter; (3) Use a bolt in each hole in each temporary bolted connection that uses a flange other than one that meets ANSI standards; (4) Use a bolt in each hole of each permanently connected flange; (5) Use...

33 CFR 156.130 - Connection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... material in joints and couplings to ensure a leak-free seal; (2) Use a bolt in at least every other hole... chapter; (3) Use a bolt in each hole in each temporary bolted connection that uses a flange other than one that meets ANSI standards; (4) Use a bolt in each hole of each permanently connected flange; (5) Use...

33 CFR 156.130 - Connection.

Code of Federal Regulations, 2010 CFR

2010-07-01

... material in joints and couplings to ensure a leak-free seal; (2) Use a bolt in at least every other hole... chapter; (3) Use a bolt in each hole in each temporary bolted connection that uses a flange other than one that meets ANSI standards; (4) Use a bolt in each hole of each permanently connected flange; (5) Use...

Low-cost composite blades for the Mod-0A wind turbines

NASA Technical Reports Server (NTRS)

Weingart, O.

1982-01-01

Low cost approaches to the design and fabrication of blades for a two-bladed 200 kW wind turbine were identified and the applicability of the techniques to larger and smaller blades was assessed. Blade tooling was designed and fabricated. Two complete blades and a partial blade for tool tryout were built. The patented TFT process was used to wind the entire blade. This process allows rapid winding of an axially oriented composite onto a tapered mandrel, with tapered wall thickness. The blade consists of a TFT glass-epoxy airfoil structure filament wound onto a steel root end fitting. The fitting is, in turn, bolted to a conical steel adapter section to provide for mounting attachment to the hub. Structural analysis, blade properties, and cost and weight analysis are described.

Reversible fastener clamp load monitor with continuous visual or remote readout

NASA Astrophysics Data System (ADS)

Hodge, Malcolm H.; Kausel, Theodore C., Jr.; Begley, Matthew R.

1998-03-01

SIMS has developed a simple means for detecting and monitoring both absolute and relative clamp load, or bolt tension, in fastener systems. More than twenty-five percent of automotive failures are known to be due to undetected loss of fastener clamp load. While the equivalent aerospace maintenance statistics are not known, the average automobile has 3,500 fasteners while a Boeing 747 has closer to one million. It is therefore anticipated that the new SensaBolt clamp load tracking system could find wide applications in the aerospace arena. We describe a visually-evident and retrofitted clamp load monitoring design which is based on the differential joint substrate compression at, and immediately adjacent to, the fastener location. This intrinsically-accurate indicator does not necessarily require alteration in either the bolt or nut geometries, thereby facilitating product introduction and retrofit in aging aircraft applications. In addition, SensaBolt's sole reliance on substrate compression renders it more accurate then torque wrench or turn-of-nut techniques. Readout may be accomplished by any of three principal methods: for those applications with ease of access to the sensor, loss of tension can be determined by direct visual inspection. Application of a standard wrench can then be made to restore the fastener's proper tightness, per the SensaBolt indicators. In those instances where line-of-sight is unimpeded and more formal inspection is desired, the SensaBolt may be interrogated by a laser scanner bar code reader. Finally, SensaBolt may be addressed by the SIMS fiber optic harness for those instances where full-time remote interrogation is desired.

Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.).

PubMed

La, Gui-xiao; Fang, Ping; Teng, Yi-bo; Li, Ya-juan; Lin, Xian-yong

2009-06-01

The effects of CO(2) enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO(2) concentration was elevated from 350 to 800 microl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO(2) concentration, N concentration, and CO(2)xN interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO(2). However, at 20 mmol N/L, elevated CO(2) had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO(2) concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO(2) concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO(2) condition.

Construct validity test of evaluation tool for professional behaviors of entry-level occupational therapy students in the United States.

PubMed

Yuen, Hon K; Azuero, Andres; Lackey, Kaitlin W; Brown, Nicole S; Shrestha, Sangita

2016-01-01

This study aimed to test the construct validity of an instrument to measure student professional behaviors in entry-level occupational therapy (OT) students in the academic setting. A total of 718 students from 37 OT programs across the United States answered a self-assessment survey of professional behavior that we developed. The survey consisted of ranking 28 attributes, each on a 5-point Likert scale. A split-sample approach was used for exploratory and then confirmatory factor analysis. A three-factor solution with nine items was extracted using exploratory factor analysis [EFA] (n=430, 60%). The factors were 'Commitment to Learning' (2 items), 'Skills for Learning' (4 items), and 'Cultural Competence' (3 items). Confirmatory factor analysis (CFA) on the validation split (n=288, 40%) indicated fair fit for this three-factor model (fit indices: CFI=0.96, RMSEA=0.06, and SRMR=0.05). Internal consistency reliability estimates of each factor and the instrument ranged from 0.63 to 0.79. Results of the CFA in a separate validation dataset provided robust measures of goodness-of-fit for the three-factor solution developed in the EFA, and indicated that the three-factor model fitted the data well enough. Therefore, we can conclude that this student professional behavior evaluation instrument is a structurally validated tool to measure professional behaviors reported by entry-level OT students. The internal consistency reliability of each individual factor and the whole instrument was considered to be adequate to good.

Fatigue Analysis of Proton Exchange Membrane Fuel Cell Stacks Based on Structural Stress Distribution

NASA Astrophysics Data System (ADS)

Wu, C. W.; Liu, B.; Wei, M. Y.; Liu, L. F.

2017-05-01

Proton exchange membrane fuel cell (PEMFC) stack usually undergoes various vibrations during packing, transportation and serving time, in particular for those used in the automobiles and portable equipment. Based on the Miner fatigue damage theory, the fatigue lives of the fuel cell components are first assessed. Then the component fatigue life contours of the stack are obtained under four working conditions, i.e. the three single-axial (in X-, Y- and Z-axis separately) and multi-axial random vibrations. Accordingly, the component damage under various vibrations is evaluated. The stress distribution on the gasket and PEM will greatly affect their fatigue lives. Finally, we compare the fatigue lives of 4-bolt- and 6-bolt-clamping stacks under the same total clamping force, and find that increasing the bolt number could improve the bolt fatigue lives.

Thrust bolting: roof bolt support apparatus

DOEpatents

Tadolini, Stephen C.; Dolinar, Dennis R.

1992-01-01

A method of installing a tensioned roof bolt in a borehole of a rock formation without the aid of a mechanical anchoring device or threaded tensioning threads by applying thrust to the bolt (19) as the bonding material (7') is curing to compress the strata (3) surrounding the borehole (1), and then relieving the thrust when the bonding material (7') has cured.

NASA's Radio Frequency Bolt Monitor: A Lifetime of Spinoffs

NASA Technical Reports Server (NTRS)

2005-01-01

This story begins in the 1970s, when Dr. Joseph Heyman, a young scientist at NASA s Langley Research Center, was asked to support the investigation of a wind tunnel accident at a sister center. Although the work was outside of his physics background, it sparked a research focus that guided his lengthy NASA career and would earn him a slew of accolades, including NASA s highest award medals for Exceptional Leadership, Exceptional Achievement, and Exceptional Service; the coveted Silver Snoopy Astronaut Award for Space Shuttle Return to Flight; and the Arthur Fleming Award for being one of the Top Ten Federal Scientists in Government Service. He won 30 additional NASA awards, including the Agency s Invention of the Year and the Agency s highest award for technology transfer, and was the only person to ever win 4 R&D 100 Awards. Back in 1973, though, Heyman was a young civil servant with a background in physics who was asked to sit on an accident review panel. The panel met at Ames Research Center, in Moffet Field, California, and after considerable investigation, concluded that a high-pressure pebble heater used for heating gas had failed, due to improperly tightened bolts in a 1,000-pound gate valve control section. The accident showered the facility with incendiary ceramic spheres and nearly a ton of metal, but, luckily, caused no injuries. Heyman returned to Langley and began work on a solution. He developed an ultrasonic device that would measure bolt elongation, as opposed to torque, the factor typically measured in testing bolt preload or tension. Torque measurement can lead to load errors, with miscalculations as high as 80 percent that can be passed over during installation. Bolt stretch, however, is nearly always accurate to 1 percent or better. Within 1 month, he had an acoustic resonance solution that accurately determined bolt elongation. He assumed his work on this project had ended, but it was actually the start of nearly 15 years of work perfecting, improving, inventing, and modifying the "bolt monitor", all the while, filing numerous patents, presenting papers, and holding demonstrations as the technology matured. Industry engineers challenged Heyman s inventiveness, and reminded the physicist that most bolts are not perfect resonators, and that early devices required that the bolt have reasonably flat and parallel faces. The U.S. Geological Survey asked NASA for help in determining the load in mine roof bolts, which are 8- to 10-feet-long and rough cut. To solve that problem, Heyman modified the original device to operate at a lower frequency and to generate propagation modes that could be used to "lock" the instrument on a particular mode. Further work in this vein led to the development of the Pulsed Phase Locked Loop (P2L2) that worked on the mine bolts. The next set of problems involved high-strength bolts with head markings. For this solution, Heyman invented a modified P2L2 that tracked a specific phase point in the measurement wave. This class of instrumentation, well suited to measuring small changes in acoustic velocity, won the NASA "Invention of the Year" award in 1982. Other scientists and engineers have continued the evolution of this technology both inside NASA and outside of the Agency. Within NASA, the technology has been improved for medical applications, with a particular focus on intercranial pressure (ICP) monitoring.

Planned complex suicide by penetrating captive-bolt gunshot and hanging: case study and review of the literature.

PubMed

Viel, Guido; Schröder, Ann Sophie; Püschel, Klaus; Braun, Christian

2009-05-30

Captive-bolt guns or slaughterer's guns are devices widely used in meat industry and private farmer households for slaughtering animal stocks. They consist of a simple cylindrical metal tube (barrel) with a metal bolt placed in their centre (around 9-15cm long and 1-1.5cm wide). The bolt is actuated by a trigger pull and is propelled forward by compressed air or by the discharge of a blank powder gun cartridge. Violent deaths inflicted by captive-bolt guns are rarely encountered in forensic practice and are predominantly suicidal events. We report an unusual complex suicide by hanging and self-shooting with a slaughterer's gun in a 21-year-old boy. The victim after putting a ceiling fixed rope around his neck shot himself in the head (occipital region) with a Kerner captive-bolt gun. He used two mirrors (a cosmetic mirror and a man-sized one) in order to properly visualize his back and to target the occipital region of his head. Radiological data (computed tomography with three dimensional reconstruction) and autopsy findings are discussed according to the clinical and forensic literature. A brief review on planned complex suicides is also given.

Reactor shroud joint

DOEpatents

Ballas, Gary J.; Fife, Alex Blair; Ganz, Israel

1998-01-01

A shroud for a nuclear reactor is described. In one embodiment, the shroud includes first and second shroud sections, and each shroud section includes a substantially cylindrical main body having a first end and a second end. With respect to each shroud section, a flange is located at the main body first end, and the flange has a plurality of bolt openings therein and a plurality of scalloped regions. The first shroud section is welded to the second shroud section, and at least some of the bolt openings in the first shroud section flange align with respective bolt openings in the second shroud section flange. In the event that the onset of inter-granular stress corrosion cracking is ever detected in the weld between the shroud section, bolts are inserted through bolt openings in the first shroud section flange and through aligned bolt openings the second shroud section flange. Each bolt, in one embodiment, has a shank section and first and second threaded end sections. Nuts are threadedly engaged to the threaded end sections and tightened against the respective flanges.

International Space Station Powered Bolt Nut Anomaly and Failure Analysis Summary

NASA Technical Reports Server (NTRS)

Sievers, Daniel E.; Warden, Harry K.

2010-01-01

A key mechanism used in the on-orbit assembly of the International Space Station (ISS) pressurized elements is the Common Berthing Mechanism. The mechanism that effects the structural connection of the Common Berthing Mechanism halves is the Powered Bolt Assembly. There are sixteen Powered Bolt Assemblies per Common Berthing Mechanism. The Common Berthing Mechanism has a bolt which engages a self aligning Powered Bolt Nut (PBN) on the mating interface (Figure 1). The Powered Bolt Assemblies are preloaded to approximately 84.5 kN (19000 lb) prior to pressurization of the CBM. The PBNs mentioned below, manufactured in 2009, will be used on ISS future missions. An on orbit functional failure of this hardware would be unacceptable and in some instances catastrophic due to the failure of modules to mate and seal the atmosphere, risking loss of crew and ISS functions. The manufacturing processes that create the PBNs need to be strictly controlled. Functional (torque vs. tension) acceptance test failures will be the result of processes not being strictly followed. Without the proper knowledge of thread tolerances, fabrication techniques, and dry film lubricant application processes, PBNs will be, and have been manufactured improperly. The knowledge gained from acceptance test failures and the resolution of those failures, thread fabrication techniques and thread dry film lubrication processes can be applied to many aerospace mechanisms to enhance their performance. Test data and manufactured PBN thread geometry will be discussed for both failed and successfully accepted PBNs.

International Space Station Powered Bolt Nut Anomaly and Failure Analysis Summary

NASA Technical Reports Server (NTRS)

Sievers, Daniel E.; Warden, Harry K.

2010-01-01

A key mechanism used in the on-orbit assembly of the International Space Station (ISS) pressurized elements is the Common Berthing Mechanism (CBM). The mechanism that effects the structural connection of the CBM halves is the Powered Bolt Assembly. There are sixteen Powered Bolt Assemblies per CBM. The CBM has a bolt which engages a self aligning Powered Bolt Nut (PBN) on the mating interface; see Figure 1. The Powered Bolt Assemblies are preloaded to approximately 19 kilo pounds (KIPs) prior to pressurization of the CBM. The PBNs mentioned below, manufactured in 2009, will be used on ISS future missions. An on orbit functional failure of this hardware would be unacceptable and in some instances catastrophic due to the failure of modules to mate and seal the atmosphere, risking loss of crew and ISS functions. The manufacturing processes which create the PBNs need to be strictly controlled. Functional (torque vs. tension) acceptance test failures will be the result of processes not being strictly followed. Without the proper knowledge of thread tolerances, fabrication techniques, and dry film lubricant application processes, PBNs will be, and have been manufactured improperly. The knowledge gained from acceptance test failures and the resolution of those failures, thread fabrication techniques and thread dry film lubrication processes can be applied to many aerospace mechanisms to enhance their performance. Test data and manufactured PBN thread geometry will be discussed for both failed and successfully accepted PBNs.

Strain measurements in composite bolted-joint specimens

NASA Technical Reports Server (NTRS)

Hyer, M. W.; Lightfoot, M. C.; Perry, J. C.

1979-01-01

Strain data from a series of bolted joint tests is presented. Double lap, double hole, double lap, single hole, and open hole tensile specimens were tested and the strain gage locations, load strain responses, and load axial displacement responses are presented. The open hole specimens were gaged to determine strain concentration factors. The double lap, double hole specimens were gaged to determine the uniformity of the strain in the joint and the amount of load transferred past the first bolt. The measurements indicated roughly half the load passed the first bolt to be reacted by the second bolt.

Performance of Sequoyah Containment Anchorage System

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

Fanous, F.; Greimann, L.; Wassef, W.

1993-01-01

Deformation of a steel containment anchorage system during a severe accident may result in a leakage path at the containment boundaries. Current design criteria are based on either ductile or brittle failure modes of headed bolts that do not account for factors such as cracking of the containment basemat or deformation of the anchor bolt that may affect the behavior of the containment anchorage system. The purpose of this study was to investigate the performance of a typical ice condenser containment`s anchorage system. This was accomplished by analyzing the Sequoyah Containment Anchorage System. Based on a strength of materials approachmore » and assuming that the anchor bolts are resisting the uplift caused by the internal pressure, one can estimate that the failure of the anchor bolts would occur at a containment pressure of 79 psig. To verify these results and to calibrate the strength of materials equation, the Sequoyah containment anchorage system was analyzed with the ABAQUS program using a three-dimensional, finite-element model. The model included portions of the steel containment building, shield building, anchor bolt assembly, reinforced concrete mat and soil foundation material.« less

78 FR 69595 - Airworthiness Directives; AgustaWestland S.p.A. (Type Certificate Formerly Held by Agusta S.p.A...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-20

... require recurring visual inspections of the tail rotor (T/R) blade retaining bolts (bolts) for a crack, corrosion, damage, or missing cadmium plating in the central part of the bolt. If a crack is not detected by.... Replacing a cracked or damaged bolt would be required before further flight. This proposed AD is prompted by...

78 FR 11214 - Merchant Marine Personnel Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-15

..., 2013 in Houston, TX, to discuss various issues related to the training and fitness of merchant marine..., documentation, and fitness standards. The Committee will advise, consult with, and make recommendations... Certification of Fitness for Entry Level Ratings); and Development of competency requirements for engineers...

Detail of "pin" or large bolt used to assemble the ...

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

Detail of "pin" or large bolt used to assemble the truss pieces. This "pin" is on pony truss; similar pins were used on movable span. - Naval Supply Annex Stockton, Rough & Ready Island, Stockton, San Joaquin County, CA

Validating a multiple mini-interview question bank assessing entry-level reasoning skills in candidates for graduate-entry medicine and dentistry programmes.

PubMed

Roberts, Chris; Zoanetti, Nathan; Rothnie, Imogene

2009-04-01

The multiple mini-interview (MMI) was initially designed to test non-cognitive characteristics related to professionalism in entry-level students. However, it may be testing cognitive reasoning skills. Candidates to medical and dental schools come from diverse backgrounds and it is important for the validity and fairness of the MMI that these background factors do not impact on their scores. A suite of advanced psychometric techniques drawn from item response theory (IRT) was used to validate an MMI question bank in order to establish the conceptual equivalence of the questions. Bias against candidate subgroups of equal ability was investigated using differential item functioning (DIF) analysis. All 39 questions had a good fit to the IRT model. Of the 195 checklist items, none were found to have significant DIF after visual inspection of expected score curves, consideration of the number of applicants per category, and evaluation of the magnitude of the DIF parameter estimates. The question bank contains items that have been studied carefully in terms of model fit and DIF. Questions appear to measure a cognitive unidimensional construct, 'entry-level reasoning skills in professionalism', as suggested by goodness-of-fit statistics. The lack of items exhibiting DIF is encouraging in a contemporary high-stakes admission setting where candidates of diverse personal, cultural and academic backgrounds are assessed by common means. This IRT approach has potential to provide assessment designers with a quality control procedure that extends to the level of checklist items.

More Nuts and Bolts of Michaelis-Menten Enzyme Kinetics

ERIC Educational Resources Information Center

Lechner, Joseph H.

2011-01-01

Several additions to a classroom activity are proposed in which an "enzyme" (the student) converts "substrates" (nut-bolt assemblies) into "products" (separated nuts and bolts) by unscrewing them. (Contains 1 table.)

Research on Creep Relaxation Non-uniformity and Effect on Performance of Combined Rotor

NASA Astrophysics Data System (ADS)

Liu, Qingya; He, Jingfei; Zhao, Lijia

2017-11-01

The combined rotor of gas turbine is connected by a certain number of rod bolts. It works in the high temperature environment for a long time, and the rod bolts will creep and relax. Under the influence of elastic interaction, the loss of pretightening force of rod bolts at different positions is non-uniform, which will cause the connection of the combined rotor to be out of tune. In this paper, the creep relaxation non-uniformity model for a class F heavy duty gas turbine is established. On the basis of this, the performance degradation and structural strength change of combined rotor resulting from creep relaxation non-uniformity of rod bolts are studied. The results show that the ratio of preload mistuning increases with time and then converges, and there is a threshold inflection point in about seven thousand hours.

Yield of pallet cants and lumber from hardwood poletimber thinnings

Treesearch

E. Paul Craft; David M. Emanuel

1981-01-01

Woods-run bolts in 4- and 6-foot length from poletimber stand thininings were classified into five quality classes, and the absolute sweep was measured for each bolt. Cants 4 by 4 and 4 by 6 inches were sawn from these bolts. The cants were classified by an interim classification system for the production of pallet parts. In contrast to straight bolts, sweep from 0.6...

A microprocessor based portable bolt tension monitor

NASA Technical Reports Server (NTRS)

Perey, D. F.

1991-01-01

A bolt tension monitor (BTM) which uses ultrasonics and a pulsed phase locked loop circuit to measure load-induced acoustic phase shifts which are independent of friction is described. The BTM makes it possible to measure the load in a bolt that was tightened at some time in the past. This capability to recertify a load after-the-fact will help to insure the integrity of a bolted joint.

Reactor shroud joint

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

Ballas, G.J.; Fife, A.B.; Ganz, I.

1998-04-07

A shroud for a nuclear reactor is described. In one embodiment, the shroud includes first and second shroud sections, and each shroud section includes a substantially cylindrical main body having a first end and a second end. With respect to each shroud section, a flange is located at the main body first end, and the flange has a plurality of bolt openings therein and a plurality of scalloped regions. The first shroud section is welded to the second shroud section, and at least some of the bolt openings in the first shroud section flange align with respective bolt openings inmore » the second shroud section flange. In the event that the onset of inter-granular stress corrosion cracking is ever detected in the weld between the shroud section, bolts are inserted through bolt openings in the first shroud section flange and through aligned bolt openings the second shroud section flange. Each bolt, in one embodiment, has a shank section and first and second threaded end sections. Nuts are threadedly engaged to the threaded end sections and tightened against the respective flanges. 4 figs.« less

Reactor shroud joint

DOEpatents

Ballas, G.J.; Fife, A.B.; Ganz, I.

1998-04-07

A shroud for a nuclear reactor is described. In one embodiment, the shroud includes first and second shroud sections, and each shroud section includes a substantially cylindrical main body having a first end and a second end. With respect to each shroud section, a flange is located at the main body first end, and the flange has a plurality of bolt openings therein and a plurality of scalloped regions. The first shroud section is welded to the second shroud section, and at least some of the bolt openings in the first shroud section flange align with respective bolt openings in the second shroud section flange. In the event that the onset of inter-granular stress corrosion cracking is ever detected in the weld between the shroud section, bolts are inserted through bolt openings in the first shroud section flange and through aligned bolt openings the second shroud section flange. Each bolt, in one embodiment, has a shank section and first and second threaded end sections. Nuts are threadedly engaged to the threaded end sections and tightened against the respective flanges. 4 figs.

High-speed plasma imaging: A lightning bolt

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

Wurden, G.A.; Whiteson, D.O.

Using a gated intensified digital Kodak Ektapro camera system, the authors captured a lightning bolt at 1,000 frames per second, with 100-{micro}s exposure time on each consecutive frame. As a thunder storm approaches while darkness descended (7:50 pm) on July 21, 1994, they photographed lightning bolts with an f22 105-mm lens and 100% gain on the intensified camera. This 15-frame sequence shows a cloud to ground stroke at a distance of about 1.5 km, which has a series of stepped leaders propagating downwards, following by the upward-propagating main return stroke.

Bolt and nut evaluator

NASA Technical Reports Server (NTRS)

Kerley, James J. (Inventor); Burkhardt, Raymond (Inventor); White, Steven (Inventor)

1994-01-01

A device for testing fasteners such as nuts and bolts is described which consists of a fixed base plate having a number of threaded and unthreaded holes of varying size for receiving the fasteners to be tested, a torque marking paper taped on top the fixed base plate for marking torque-angle indicia, a torque wrench for applying torque to the fasteners being tested, and an indicator for showing the torque applied to the fastener. These elements provide a low cost, nondestructive device for verifying the strength of bolts and nuts.

Static Strength Characteristics of Mechanically Fastened Composite Joints

NASA Technical Reports Server (NTRS)

Fox, D. E.; Swaim, K. W.

1999-01-01

The analysis of mechanically fastened composite joints presents a great challenge to structural analysts because of the large number of parameters that influence strength. These parameters include edge distance, width, bolt diameter, laminate thickness, ply orientation, and bolt torque. The research presented in this report investigates the influence of some of these parameters through testing and analysis. A methodology is presented for estimating the strength of the bolt-hole based on classical lamination theory using the Tsai-Hill failure criteria and typical bolthole bearing analytical methods.

Shear fracture of jointed steel plates of bolted joints under impact load

NASA Astrophysics Data System (ADS)

Daimaruya, M.; Fujiki, H.; Ambarita, H.; Kobayashi, H.; Shin, H.-S.

2013-07-01

The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of bolted joints used in a car body, which contributes to crash simulations by CAE. We focus our attention on the shear fracture of the jointed steel plates of lap-bolted joints in the suspension of a car under impact load. Members of lap-bolted joints are modelled as a pair of steel plates connected by a bolt. One of the plates is a specimen subjected to plastic deformation and fracture and the other is a jig subjected to elastic deformation only. Three kinds of steel plate specimens are examined, i.e., a common steel plate with a tensile strength of 270 MPa and high tensile strength steel plates of 440 and 590 MPa used for cars. The impact shear test was performed using the split Hopkinson bar technique for tension impact, together with the static test using a universal testing machine INSTRON 5586. The behaviour of the shear stress and deformation up to rupture taking place in the joint was discussed. The obtained results suggest that a stress-based fracture criterion may be developed for the impact fracture of jointed steel plates of a lap-bolted joint.

Inexpensive Bolt-Load Gage

NASA Technical Reports Server (NTRS)

Long, M. J.

1983-01-01

"Built-in" gage determines whether large bolt or stud has been torqued to desired load and provides for continuous inspection to ensure proper load is being maintained. Gage detects longitudinal stress/strain bolt; requires no electronic or sonic test equipment.

78 FR 40757 - Merchant Marine Personnel Advisory Committee: Intercessional Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-08

... CG-719K/E, Merchant Mariner Evaluation of Fitness for Entry Level Ratings.'' This meeting will be..., qualifications, certification, documentation, and fitness standards. The Committee will advise, consult with, and..., Merchant Mariner Credential Medical Evaluation Report and CG-719K/E, Merchant Mariner Evaluation of Fitness...

Trestle #1, detail of bolts on northeast abutment lower vertical ...

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

Trestle #1, detail of bolts on northeast abutment lower vertical support timbers. View to north - Promontory Route Railroad Trestles, S.P. Trestle 779.91, One mile southwest of junction of State Highway 83 and Blue Creek, Corinne, Box Elder County, UT

Trestle #1, detail of connecting bolts and spikes on upper ...

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

Trestle #1, detail of connecting bolts and spikes on upper northeast abutment. View to east - Promontory Route Railroad Trestles, S.P. Trestle 779.91, One mile southwest of junction of State Highway 83 and Blue Creek, Corinne, Box Elder County, UT

KSC-2013-2344

NASA Image and Video Library

2013-05-13

CAPE CANAVERAL, Fla. -- At NASA’s Kennedy Space Center in Florida, Lockheed Martin crews begin uncovering the Orion ground test vehicle in the Launch Equipment Test Facility, or LETF. The GTA was moved from the Operations and Checkout Facility to the LETF for a series of pyrotechnic bolt tests. The GTA is being used for path finding operations in the O&C, including simulated manufacturing and assembly procedures. Launching atop NASA's heavy-lift Space Launch System SLS, which also is under development, the Orion Multi-Purpose Crew Vehicle MPCV will serve as the exploration vehicle that will carry astronaut crews beyond low Earth orbit. It also will provide emergency abort capabilities, sustain the crew during space travel and provide safe re-entry from deep space return velocities. For more information, visit www.nasa.gov/orion. Photo credit: Jim Grossman

KSC-2013-2345

NASA Image and Video Library

2013-05-13

CAPE CANAVERAL, Fla. -- At NASA’s Kennedy Space Center in Florida, Lockheed Martin crews uncover the Orion ground test vehicle in the Launch Equipment Test Facility, or LETF. The GTA was moved from the Operations and Checkout Facility to the LETF for a series of pyrotechnic bolt tests. The GTA is being used for path finding operations in the O&C, including simulated manufacturing and assembly procedures. Launching atop NASA's heavy-lift Space Launch System SLS, which also is under development, the Orion Multi-Purpose Crew Vehicle MPCV will serve as the exploration vehicle that will carry astronaut crews beyond low Earth orbit. It also will provide emergency abort capabilities, sustain the crew during space travel and provide safe re-entry from deep space return velocities. For more information, visit www.nasa.gov/orion. Photo credit: Jim Grossman

Pneumatic wrench retains or discharges nuts or bolts as desired

NASA Technical Reports Server (NTRS)

Bouille, J. R.

1966-01-01

Pneumatic wrench grips, screws or unscrews, and discharges a nut or bolt as desired. The device consists of a standard pneumatic wrench modified with a special hex bolt head socket assembly and a diaphragm air cylinder.

Analysis of Modeling Parameters on Threaded Screws.

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

Vigil, Miquela S.; Brake, Matthew Robert; Vangoethem, Douglas

2015-06-01

Assembled mechanical systems often contain a large number of bolted connections. These bolted connections (joints) are integral aspects of the load path for structural dynamics, and, consequently, are paramount for calculating a structure's stiffness and energy dissipation prop- erties. However, analysts have not found the optimal method to model appropriately these bolted joints. The complexity of the screw geometry cause issues when generating a mesh of the model. This paper will explore different approaches to model a screw-substrate connec- tion. Model parameters such as mesh continuity, node alignment, wedge angles, and thread to body element size ratios are examined. Themore » results of this study will give analysts a better understanding of the influences of these parameters and will aide in finding the optimal method to model bolted connections.« less

Secondary skull fractures in head wounds inflicted by captive bolt guns: autopsy findings and experimental simulation.

PubMed

Perdekamp, Markus Grosse; Kneubuehl, Beat P; Ishikawa, Takaki; Nadjem, Hadi; Kromeier, Jan; Pollak, Stefan; Thierauf, Annette

2010-11-01

Apart from one article published by Rabl and Sigrist in 1992 (Rechtsmedizin 2:156-158), there are no further reports on secondary skull fractures in shots from captive bolt guns. Up to now, the pertinent literature places particular emphasis on the absence of indirect lesions away from the impact point, when dealing with the wounding capacity of slaughterer's guns. The recent observation of two suicidal head injuries accompanied by skull fractures far away from the bolt's path gave occasion to experimental studies using simulants (glycerin soap, balls from gelatin) and skull–brain models. As far as ballistic soap was concerned, the dimensions of the bolt's channel were assessed by multi-slice computed tomography before cutting the blocks open. The test shots to gelatin balls and to skull-brain models were documented by means of a high-speed motion camera. As expected, the typical temporary cavity effect of bullets fired from conventional guns could not be observed when captive bolt stunners were discharged. Nevertheless, the visualized transfer of kinetic energy justifies the assumption that the secondary fractures seen in thin parts of the skull were caused by a hydraulic burst effect.

Grainex Mar-M 247 Turbine Disk Life Study for NASA's High Temperature High Speed Turbine Seal Test Facility

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.

2015-01-01

An experimental and analytical fatigue life study was performed on the Grainex Mar-M 247 disk used in NASA s Turbine Seal Test Facility. To preclude fatigue cracks from growing to critical size in the NASA disk bolt holes due to cyclic loading at severe test conditions, a retirement-for-cause methodology was adopted to detect and monitor cracks within the bolt holes using eddy-current inspection. For the NASA disk material that was tested, the fatigue strain-life to crack initiation at a total strain of 0.5 percent, a minimum to maximum strain ratio of 0, and a bolt hole temperature of 649 C was calculated to be 665 cycles using -99.95 percent prediction intervals. The fatigue crack propagation life was calculated to be 367 cycles after implementing a safety factor of 2 on life. Thus, the NASA disk bolt hole total life or retirement life was determined to be 1032 cycles at a crack depth of 0.501 mm. An initial NASA disk bolt hole inspection at 665 cycles is suggested with 50 cycle inspection intervals thereafter to monitor fatigue crack growth.

Least-Squares Curve-Fitting Program

NASA Technical Reports Server (NTRS)

Kantak, Anil V.

1990-01-01

Least Squares Curve Fitting program, AKLSQF, easily and efficiently computes polynomial providing least-squares best fit to uniformly spaced data. Enables user to specify tolerable least-squares error in fit or degree of polynomial. AKLSQF returns polynomial and actual least-squares-fit error incurred in operation. Data supplied to routine either by direct keyboard entry or via file. Written for an IBM PC X/AT or compatible using Microsoft's Quick Basic compiler.

Tapping and listening: a new approach to bolt looseness monitoring

NASA Astrophysics Data System (ADS)

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

2018-07-01

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

Lamb Wave-Based Structural Health Monitoring on Composite Bolted Joints under Tensile Load

PubMed Central

Yang, Bin; Xuan, Fu-Zhen; Xiang, Yanxun; Li, Dan; Zhu, Wujun; Tang, Xiaojun; Xu, Jichao; Yang, Kang; Luo, Chengqiang

2017-01-01

Online and offline monitoring of composite bolted joints under tensile load were investigated using piezoelectric transducers. The relationships between Lamb wave signals, pre-tightening force, the applied tensile load, as well as the failure modes were investigated. Results indicated that S0/A0 wave amplitudes decrease with the increasing of load. Relationships between damage features and S0/A0 mode were built based on the finite element (FE) simulation and experimental results. The possibility of application of Lamb wave-based structure health monitoring in bolted joint-like composite structures was thus achieved. PMID:28773014

Trestle #1, detail of connecting bolts and spikes on northeast ...

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

Trestle #1, detail of connecting bolts and spikes on northeast abutment vertical support timbers. View to east - Promontory Route Railroad Trestles, S.P. Trestle 779.91, One mile southwest of junction of State Highway 83 and Blue Creek, Corinne, Box Elder County, UT

Trestle #1, detail of spacer, bolt, and spikes on northeast ...

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

Trestle #1, detail of spacer, bolt, and spikes on northeast end of deck. View to southwest - Promontory Route Railroad Trestles, S.P. Trestle 779.91, One mile southwest of junction of State Highway 83 and Blue Creek, Corinne, Box Elder County, UT

Detail of "pin" or large bolt used to assemble the ...

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

Detail of "pin" or large bolt used to assemble the truss pieces. This "pin" is on pony truss; similar pins were used on movable span. - Naval Supply Annex Stockton, Daggett Road Bridge, Daggett Road traversing Burns Cut Off, Stockton, San Joaquin County, CA

An impedance-based approach for detection and quantification of damage in cracked plates and loose bolts in bridge structures

NASA Astrophysics Data System (ADS)

Rabiei, Masoud; Sheldon, Jeremy; Palmer, Carl

2012-04-01

The applicability of Electro-Mechanical Impedance (EMI) approach to damage detection, localization and quantification in a mobile bridge structure is investigated in this paper. The developments in this paper focus on assessing the health of Armored Vehicle Launched Bridges (AVLBs). Specifically, two key failure mechanisms of the AVLB to be monitored were fatigue crack growth and damaged (loose) rivets (bolts) were identified. It was shown through experiment that bolt damage (defined here as different torque levels applied to bolts) can be detected, quantified and located using a network of lead zirconate titanate (PZT) transducers distributed on the structure. It was also shown that cracks of various sizes can be detected and quantified using the EMI approach. The experiments were performed on smaller laboratory specimens as well as full size bridge-like components that were built as part of this research. The effects of various parameters such as transducer type and size on the performance of the proposed health assessment approach were also investigated.

Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.)*

PubMed Central

La, Gui-xiao; Fang, Ping; Teng, Yi-bo; Li, Ya-juan; Lin, Xian-yong

2009-01-01

The effects of CO2 enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO2 concentration was elevated from 350 to 800 μl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO2 concentration, N concentration, and CO2×N interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO2. However, at 20 mmol N/L, elevated CO2 had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO2 concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO2 concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO2 condition. PMID:19489111

Trestle #1, detail of bolt and washer on wing wall ...

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

Trestle #1, detail of bolt and washer on wing wall on north west side of northeast abutment. View to northeast - Promontory Route Railroad Trestles, S.P. Trestle 779.91, One mile southwest of junction of State Highway 83 and Blue Creek, Corinne, Box Elder County, UT

Monolithic Flexure Pre-Stressed Ultrasonic Horns

NASA Technical Reports Server (NTRS)

Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph; Allen, Phillip Grant

2011-01-01

High-power ultrasonic actuators are generally assembled with a horn, backing, stress bolt, piezoelectric rings, and electrodes. The manufacturing process is complex, expensive, difficult, and time-consuming. The internal stress bolt needs to be insulated and presents a potential internal discharge point, which can decrease actuator life. Also, the introduction of a center hole for the bolt causes many failures, reducing the throughput of the manufactured actuators. A new design has been developed for producing ultrasonic horn actuators. This design consists of using flexures rather than stress bolts, allowing one to apply pre-load to the piezoelectric material. It also allows one to manufacture them from a single material/plate, rapid prototype them, or make an array in a plate or 3D structure. The actuator is easily assembled, and application of pre-stress greater than 25 MPa was demonstrated. The horn consists of external flexures that eliminate the need for the conventional stress bolt internal to the piezoelectric, and reduces the related complexity. The stress bolts are required in existing horns to provide prestress on piezoelectric stacks when driven at high power levels. In addition, the manufacturing process benefits from the amenability to produce horn structures with internal cavities. The removal of the pre-stress bolt removes a potential internal electric discharge point in the actuator. In addition, it significantly reduces the chances of mechanical failure in the piezoelectric stacks that result from the hole surface in conventional piezoelectric actuators. The novel features of this disclosure are: 1. A design that can be manufactured from a single piece of metal using EDM, precision machining, or rapid prototyping. 2. Increased electromechanical coupling of the horn actuator. 3. Higher energy density. 4. A monolithic structure of a horn that consists of an external flexure or flexures that can be used to pre-stress a solid piezoelectric structure rather than a bolt, which requires a through hole in the piezoelectric material. 5. A flexure system with low stiffness that accommodates mechanical creep with minor reduction in pre-stress.

Square cants from round bolts without slabs or sawdust

Treesearch

Peter Koch

1960-01-01

For maximum efficiency a headrig for converting bark-free bolts into cants must (1) have a fast cycle time, (2) require minimum handling of bolts and refuse, and (3) convert the volume represented by slabs and kerf into a salable byproduct.

Explosive Bolt Dual-Initiated from One Side

NASA Technical Reports Server (NTRS)

Snow, Eric

2011-01-01

An explosive bolt has been developed that has a one-sided dual initiation train all the way down to the pyro charge for high reliability, while still allowing the other side of the bolt to remain in place after actuation to act as a thermal seal in an extremely high-temperature environment. This lightweight separation device separates at a single fracture plane, and has as much redundancy/reliability as possible. The initiation train comes into the explosive bolt from one side.

Mechanical testing and development of the helical field coil joint for the Advanced Toroidal Facility

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

Nelson, B.E.; Bryan, W.E.; Goranson, P.L.

1985-01-01

The helical field (HF) coil set for the Advanced Toroidal Facility (ATF) is an M = 12, l = 2, constant-ratio torsatron winding consisting of 2 coils, each with 14 turns of heavy copper conductor. The coils are divided into 24 identical segments to facilitate fabrication and minimize the assembly schedule. The segments are connected across through-bolted lap joints that must carry up to 124,000 A per turn for 5 s or 62,500 A steady-state. In addition, the joints must carry the high magnetic and thermal loads induced in the conductor and still fit within the basic 140- by 30-mmmore » copper envelope. Extensive testing and development were undertaken to verify and refine the basic joint design. Tests included assembly force and clamping force for various types of misalignment; joint resistance as a function of clamping force; clamp bolt relaxation due to thermal cycling; fatigue testing of full-size, multiturn joint prototypes; and low-cycle fatigue and tensile tests of annealed CDA102 copper. The required performance parameters and actual test results, as well as the final joint configuration, are presented. 2 refs., 9 figs., 4 tabs.« less

Structural Analysis of the Redesigned Ice/Frost Ramp Bracket

NASA Technical Reports Server (NTRS)

Phillips, D. R.; Dawicke, D. S.; Gentz, S. J.; Roberts, P. W.; Raju, I. S.

2007-01-01

This paper describes the interim structural analysis of a redesigned Ice/Frost Ramp bracket for the Space Shuttle External Tank (ET). The proposed redesigned bracket consists of mounts for attachment to the ET wall, supports for the electronic/instrument cables and propellant repressurization lines that run along the ET, an upper plate, a lower plate, and complex bolted connections. The eight nominal bolted connections are considered critical in the summarized structural analysis. Each bolted connection contains a bolt, a nut, four washers, and a non-metallic spacer and block that are designed for thermal insulation. A three-dimensional (3D) finite element model of the bracket is developed using solid 10-node tetrahedral elements. The loading provided by the ET Project is used in the analysis. Because of the complexities associated with accurately modeling the bolted connections in the bracket, the analysis is performed using a global/local analysis procedure. The finite element analysis of the bracket identifies one of the eight bolted connections as having high stress concentrations. A local area of the bracket surrounding this bolted connection is extracted from the global model and used as a local model. Within the local model, the various components of the bolted connection are refined, and contact is introduced along the appropriate interfaces determined by the analysts. The deformations from the global model are applied as boundary conditions to the local model. The results from the global/local analysis show that while the stresses in the bolts are well within yield, the spacers fail due to compression. The primary objective of the interim structural analysis is to show concept viability for static thermal testing. The proposed design concept would undergo continued design optimization to address the identified analytical assumptions and concept shortcomings, assuming successful thermal testing.

Method for molding threads in graphite panels

DOEpatents

Short, W.W.; Spencer, C.

1994-11-29

A graphite panel with a hole having a damaged thread is repaired by drilling the hole to remove all of the thread and making a new hole of larger diameter. A bolt with a lubricated thread is placed in the new hole and the hole is packed with graphite cement to fill the hole and the thread on the bolt. The graphite cement is cured, and the bolt is unscrewed therefrom to leave a thread in the cement which is at least as strong as that of the original thread. 8 figures.

Cable clamp bolt fixture facilitates assembly in close quarters

NASA Technical Reports Server (NTRS)

Sunderland, G. H.

1967-01-01

Cable clamp bolt holding fixture facilitates forming of electrical cable runs in limited equipment space. The fixture engages the threads of the short clamp bolt through the clamp and maintains tension against clamp tendency to open while the operator installs the nut without difficulty.

Design Considerations for Abrasive Blast Rooms and Recovery Systems

DTIC Science & Technology

2010-02-01

COLUMN BOLT – ALLOWS FOR WIDER ENCLOSURES – STRONG ENOUGH TO SUPPORT MONORAIL Flange Bolt Room Column Bolt Room • Structural steel framework...OVERHEAD MONORAILS • EXTERIOR WORK STATIONS • TURNTABLES • HORIZONTAL ROTATION DEVICES OVERHEAD MONORAIL Workpiece Handling • Powered horizontal rotation

The Load Distribution in Bolted or Riveted Joints in Light-Alloy Structures

NASA Technical Reports Server (NTRS)

Vogt, F.

1947-01-01

This report contains a theoretical discussion of the load distribution in bolted or riveted joints in light-alloy structures which is applicable not only for loads below the limit of proportionality but also for loads above this limit. The theory is developed for double and single shear joints. The methods given are illustrated by numerical examples and the values assumed for the bolt (or rivet) stiffnesses are based partly on theory and partly on known experimental values. It is shown that the load distribution does not vary greatly with the bolt (or rivet) stiffnesses and that for design purposes it is usually sufficient to know their order of magnitude. The theory may also be directly used for spot-welded structures and, with small modifications, for seam-welded structures, The computational work involved in the methods described is simple and may be completed in a reasonable time for most practical problems. A summary of earlier theoretical and experimental investigations on the subject is included in the report.

Finite element model study of the effect of corner rounding on detectability of corner cracks using bolt hole eddy current

NASA Astrophysics Data System (ADS)

Underhill, P. R.; Krause, T. W.

2017-02-01

Recent work has shown that the detectability of corner cracks in bolt-holes is compromised when rounding of corners arises, as might occur during bolt-hole removal. Probability of Detection (POD) studies normally require a large number of samples of both fatigue cracks and electric discharge machined notches. In the particular instance of rounding of bolt-hole corners the generation of such a large set of samples representing the full spectrum of potential rounding would be prohibitive. In this paper, the application of Finite Element Method (FEM) modeling is used to supplement the study of detection of cracks forming at the rounded corners of bolt-holes. FEM models show that rounding of the corner of the bolt-hole reduces the size of the response to a corner crack to a greater extent than can be accounted for by loss of crack area. This reduced sensitivity can be ascribed to a lower concentration of eddy currents at the rounded corner surface and greater lift-off of pick-up coils relative to that of a straight-edge corner. A rounding with a radius of 0.4 mm (.016 inch) showed a 20% reduction in the strength of the crack signal. Assuming linearity of the crack signal with crack size, this would suggest an increase in the minimum detectable size by 25%.

A Method to Capture Macroslip at Bolted Interfaces

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

Hopkins, Ronald Neil; Heitman, Lili Anne Akin

2015-10-01

Relative motion at bolted connections can occur for large shock loads as the internal shear force in the bolted connection overcomes the frictional resistive force. This macroslip in a structure dissipates energy and reduces the response of the components above the bolted connection. There is a need to be able to capture macroslip behavior in a structural dynamics model. A linear model and many nonlinear models are not able to predict marcoslip effectively. The proposed method to capture macroslip is to use the multi-body dynamics code ADAMS to model joints with 3-D contact at the bolted interfaces. This model includesmore » both static and dynamic friction. The joints are preloaded and the pinning effect when a bolt shank impacts a through hole inside diameter is captured. Substructure representations of the components are included to account for component flexibility and dynamics. This method was applied to a simplified model of an aerospace structure and validation experiments were performed to test the adequacy of the method.« less

Load apparatus and method for bolt-loaded compact tension test specimen

DOEpatents

Buescher, B.J. Jr.; Lloyd, W.R.; Ward, M.B.; Epstein, J.S.

1997-02-04

A bolt-loaded compact tension test specimen load apparatus includes: (a) a body having first and second opposing longitudinal ends, the first end comprising an externally threaded portion sized to be threadedly received within the test specimen threaded opening; (b) a longitudinal loading rod having first and second opposing longitudinal ends, the loading rod being slidably received in a longitudinal direction within the body internally through the externally threaded portion and slidably extending longitudinally outward of the body first longitudinal end; (c) a force sensitive transducer slidably received within the body and positioned to engage relative to the loading rod second longitudinal end; and (d) a loading bolt threadedly received relative to the body, the loading bolt having a bearing end surface and being positioned to bear against the transducer to forcibly sandwich the transducer between the loading bolt and loading rod. Also disclosed is a method of in situ determining applied force during crack propagation in a bolt-loaded compact tension test specimen. 6 figs.

Load apparatus and method for bolt-loaded compact tension test specimen

DOEpatents

Buescher, Jr., Brent J.; Lloyd, W. Randolph; Ward, Michael B.; Epstein, Jonathan S.

1997-01-01

A bolt-loaded compact tension test specimen load apparatus includes: a) a body having first and second opposing longitudinal ends, the first end comprising an externally threaded portion sized to be threadedly received within the test specimen threaded opening; b) a longitudinal loading rod having first and second opposing longitudinal ends, the loading rod being slidably received in a longitudinal direction within the body internally through the externally threaded portion and slidably extending longitudinally outward of the body first longitudinal end; c) a force sensitive transducer slidably received within the body and positioned to engage relative to the loading rod second longitudinal end; and d) a loading bolt threadedly received relative to the body, the loading bolt having a bearing end surface and being positioned to bear against the transducer to forcibly sandwich the transducer between the loading bolt and loading rod. Also disclosed is a method of in situ determining applied force during crack propagation in a bolt-loaded compact tension test specimen.

A Method to Capture Macroslip at Bolted Interfaces [PowerPoint

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

Hopkins, Ronald Neil; Heitman, Lili Anne Akin

2016-01-01

Relative motion at bolted connections can occur for large shock loads as the internal shear force in the bolted connection overcomes the frictional resistive force. This macroslip in a structure dissipates energy and reduces the response of the components above the bolted connection. There is a need to be able to capture macroslip behavior in a structural dynamics model. A linear model and many nonlinear models are not able to predict marcoslip effectively. The proposed method to capture macroslip is to use the multi-body dynamics code ADAMS to model joints with 3-D contact at the bolted interfaces. This model includesmore » both static and dynamic friction. The joints are preloaded and the pinning effect when a bolt shank impacts a through hole inside diameter is captured. Substructure representations of the components are included to account for component flexibility and dynamics. This method was applied to a simplified model of an aerospace structure and validation experiments were performed to test the adequacy of the method.« less

Failure modes of single and multi-bolted joint in the pultruded fiber reinforced polymer composite members

NASA Astrophysics Data System (ADS)

Kim, S. Y.; Yoo, J. H.; Kim, H. K.; Shin, K. Y.; Yoon, S. J.

2018-06-01

In this paper, we discussed the structural behavior of bolted lap-joint connections in pultruded FRP structural members. Especially, bolted connections in pultruded FRP members are investigated for their failure modes and strength. Specimens with single and multiple bolt-holes are tested in tension under bolt-loading conditions. All of the specimens are instrumented with strain gages and the load-strain responses are monitored. The failed specimens are examined for the cracks and failure patterns. The purpose of this paper is to predict the failure strength by using the ratio of the results obtained by the experiment and the finite element analysis. In the study, several tests are conducted to determine the mechanical properties of pultruded FRP materials before the main experiment. The results are used in the finite element analysis for single and multiple bolted lap-joint specimens. The results obtained by the experiment are compared with the results obtained by the finite element analysis.

Simulation and design of ECT differential bobbin probes for the inspection of cracks in bolts

NASA Astrophysics Data System (ADS)

Ra, S. W.; Im, K. H.; Lee, S. G.; Kim, H. J.; Song, S. J.; Kim, S. K.; Cho, Y. T.; Woo, Y. D.; Jung, J. A.

2015-12-01

All Various defects could be generated in bolts for a use of oil filters for the manufacturing process and then may affect to the safety and quality in bolts. Also, fine defects may be imbedded in oil filter system during multiple forging manufacturing processes. So it is very important that such defects be investigated and screened during the multiple manufacturing processes. Therefore, in order effectively to evaluate the fine defects, the design parameters for bobbin-types were selected under a finite element method (FEM) simulations and Eddy current testing (ECT). Especially the FEM simulations were performed to make characterization in the crack detection of the bolts and the parameters such as number of turns of the coil, the coil size and applied frequency were calculated based on the simulation results.

A clamping force measurement system for monitoring the condition of bolted joints on railway track joints and points

NASA Astrophysics Data System (ADS)

Tesfa, B.; Horler, G.; Thobiani, F. Al; Gu, F.; Ball, A. D.

2012-05-01

Many industrial structures associated with railway infrastructures rely on a large number of bolted joint connections to ensure safe and reliable operation of the track and trackside furniture. Significant sums of money are spent annually to repair the damage caused by bolt failures and to maintain the integrity of bolted structures. In the UK, Network Rail (the organization responsible for rail network maintenance and safety) conducts corrective and preventive maintenance manually on 26,000 sets of points (each having approximately 30 bolted joints per set), in order to ensure operational success and safety for the travelling public. Such manual maintenance is costly, disruptive, unreliable and prone to human error. The aim of this work is to provide a means of automatically measuring the clamping force of each individual bolted joint, by means of an instrumented washer. This paper describes the development of a sensor means to be used in the washer, which satisfies the following criteria. Sense changes in the clamping force of the joint and report this fact. Provide compatibility with the large dynamic range of clamping force. Satisfy the limitations in terms of physical size. Provide the means to electronically interface with the washer. Provide a means of powering the washer in situ. Provide a solution at an acceptable cost. Specifically the paper focuses on requirements 1, 2 and 3 and presents the results that support further development of the proposed design and the realization of a pre-prototype system. In the paper, various options for the force sensing element (strain gage, capacitor, piezo-resistive) have been compared, using design optimization techniques. As a result of the evaluation, piezo-resistive sensors in concert with a proprietary force attenuation method, have been found to offer the best performance and cost trade-off The performance of the novel clamping force sensor has been evaluated experimentally and the results show that a smart washer can be developed to monitor the condition of bolted joints as found on railway track and points.

Inedible Nuts and Non-Lightning Bolts

ERIC Educational Resources Information Center

Rynone, William

2010-01-01

In this article, the author provides detailed information on a wide variety of commonly used screws, bolts, and other fasteners. The information has been gathered in his engineering career and outside interests (maintenance on his car and airplane, and woodworking). The topic should be of interest to students and educators in many technical…

Sleeve Expansion of Bolt Holes in Railroad Rail : Volume II, Process Parameters and Procedures

DOT National Transportation Integrated Search

1980-02-01

The bolt-hole cold-expansion process has been applied to railroad rail in laboratory tests and has demonstrated a potential for the reduction of rail-bolt-hole-failure incidence. Limited field tests also have been conducted and are currently under lo...

Busting Bolts

ERIC Educational Resources Information Center

Scott, Alan

2013-01-01

A simple apparatus is described which serves as a materials testing laboratory. Bolts are placed in it and subjected to tensile and torsional stress while being tightened. The tensile and torsional stress and strain can be measured, which enables the determination of several mechanical properties of the bolt material, including Young's…

49 CFR 213.351 - Rail joints.

Code of Federal Regulations, 2011 CFR

2011-10-01

... replaced. (d) Each rail shall be bolted with at least two bolts at each joint. (e) Each joint bar shall be... in this subpart. (f) No rail shall have a bolt hole which is torch cut or burned. (g) No joint bar shall be reconfigured by torch cutting. ...

Preload Loss in a Spacecraft Fastener via Vibration-Induced Unwinding

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Howard, S. Adam; Hess, Daniel P.

2018-01-01

Sound engineering practice requires that fasteners and bolted joints maintain preload in service. NASA recently concluded a series of vibration tests of a multicomponent structure intended to simulate an upper stage section of a launch vehicle. The stacked components were joined through six circumferentially placed bolted cup-cone-style pyrotechnic joint mechanisms designed to share spacecraft structural loads and then enable separation during ascent. Over the course of the vibration test campaign, all six bolted cup-cone mechanisms experienced some degree of preload loss with two mechanisms losing half of their original bolt preload. A subsequent forensic anomaly investigation concluded that vibration-induced unwinding of the preload nut-and-bolt assemblies occurred despite the use of safety wire and high levels of thread friction. A series of experiments were done to better understand how large, heavily preloaded fasteners could unwind. Additionally, thread friction torque was measured and the fastener locking capability of safety wire was evaluated. The friction coefficient between the clamped cup-cone components was characterized and finally a highly instrumented mechanism-level vibration test was done to reproduce the unwinding phenomenon to better understand the mechanism's behavior. The conclusion drawn was that vibration and structural forces led to relative motion (sliding) of the clamped components, resulting in self-loosening and unwinding effects on the nut-and-bolt assembly. To counter this phenomenon, more effective fastener locking methodologies were recommended and a follow-on effort was initiated to quantify the relationship between preload, component motion, and resulting unwinding forces. It is hoped that elucidation of these effects can be used to design more effective fastener locking features.

46 CFR 98.30-27 - Connections.

Code of Federal Regulations, 2014 CFR

2014-10-01

... other hole and in no case less than four bolts in each temporary connection utilizing an American National Standards Institute (ANSI) standard flange coupling; (3) Use a bolt in each hole of couplings other than ANSI standard flange couplings; (4) Use a bolt in each hole of each permanently connected...

49 CFR 231.17 - Specifications common to all steam locomotives.

Code of Federal Regulations, 2011 CFR

2011-10-01

... shall be securely fastened with bolts, rivets, or studs. (ii) Locomotives having Wootten type boilers... inches above outside edge of running boards, securely fastened with bolts, rivets, or studs. (c... inches in height, measured from the top of end sill, and securely fastened with bolts or rivets. (f...

77 FR 29212 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-17

... Company Model 777 airplanes. This AD was prompted by reports of fractured and missing latch pin retention... inspections for fractured or missing latch pin retention bolts, replacement of existing titanium bolts with... AD to detect and correct fractured and missing latch pin retention bolts, which could result in...

Torquing preload in a lubricated bolt

NASA Technical Reports Server (NTRS)

Seegmiller, H. L.

1978-01-01

The tension preload obtained by torquing a 7/8 in. diam UNC high strength bolt was determined for lubricated and dry conditions. Consistent preload with a variation of + or - 3% was obtained when the bolt head area was lubricated prior to each torque application. Preload tensions nearly 70% greater than the value predicted with the commonly used formula occurred with the lubricated bolt. A reduction to 39% of the initial preload was observed during 50 torque applications without relubrication. Little evidence of wear was noted after 203 cycles of tightening.

Bolt beam propagation analysis

NASA Astrophysics Data System (ADS)

Shokair, I. R.

BOLT (Beam on Laser Technology) is a rocket experiment to demonstrate electron beam propagation on a laser ionized plasma channel across the geomagnetic field in the ion focused regime (IFR). The beam parameters for BOLT are: beam current I(sub b) = 100 Amps, beam energy of 1--1.5 MeV (gamma =3-4), and a Gaussian beam and channel of radii r(sub b) = r(sub c) = 1.5 cm. The N+1 ionization scheme is used to ionize atomic oxygen in the upper atmosphere. This scheme utilizes 130 nm light plus three IR lasers to excite and then ionize atomic oxygen. The limiting factor for the channel strength is the energy of the 130 nm laser, which is assumed to be 1.6 mJ for BOLT. At a fixed laser energy and altitude (fixing the density of atomic oxygen), the range can be varied by adjusting the laser tuning, resulting in a neutralization fraction axial profile of the form: f(z) = f(sub 0) e(exp minus z)/R, where R is the range. In this paper we consider the propagation of the BOLT beam and calculate the range of the electron beam taking into account the fact that the erosion rates (magnetic and inductive) vary with beam length as the beam and channel dynamically respond to sausage and hose instabilities.

An Exploratory Study on Using Principal-Component Analysis and Confirmatory Factor Analysis to Identify Bolt-On Dimensions: The EQ-5D Case Study.

PubMed

Finch, Aureliano Paolo; Brazier, John Edward; Mukuria, Clara; Bjorner, Jakob Bue

2017-12-01

Generic preference-based measures such as the EuroQol five-dimensional questionnaire (EQ-5D) are used in economic evaluation, but may not be appropriate for all conditions. When this happens, a possible solution is adding bolt-ons to expand their descriptive systems. Using review-based methods, studies published to date claimed the relevance of bolt-ons in the presence of poor psychometric results. This approach does not identify the specific dimensions missing from the Generic preference-based measure core descriptive system, and is inappropriate for identifying dimensions that might improve the measure generically. This study explores the use of principal-component analysis (PCA) and confirmatory factor analysis (CFA) for bolt-on identification in the EQ-5D. Data were drawn from the international Multi-Instrument Comparison study, which is an online survey on health and well-being measures in five countries. Analysis was based on a pool of 92 items from nine instruments. Initial content analysis provided a theoretical framework for PCA results interpretation and CFA model development. PCA was used to investigate the underlining dimensional structure and whether EQ-5D items were represented in the identified constructs. CFA was used to confirm the structure. CFA was cross-validated in random halves of the sample. PCA suggested a nine-component solution, which was confirmed by CFA. This included psychological symptoms, physical functioning, and pain, which were covered by the EQ-5D, and satisfaction, speech/cognition,relationships, hearing, vision, and energy/sleep which were not. These latter factors may represent relevant candidate bolt-ons. PCA and CFA appear useful methods for identifying potential bolt-ons dimensions for an instrument such as the EQ-5D. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Genetic analyses of bolting in bulb onion (Allium cepa L.).

PubMed

Baldwin, Samantha; Revanna, Roopashree; Pither-Joyce, Meeghan; Shaw, Martin; Wright, Kathryn; Thomson, Susan; Moya, Leire; Lee, Robyn; Macknight, Richard; McCallum, John

2014-03-01

We present the first evidence for a QTL conditioning an adaptive trait in bulb onion, and the first linkage and population genetics analyses of candidate genes involved in photoperiod and vernalization physiology. Economic production of bulb onion (Allium cepa L.) requires adaptation to photoperiod and temperature such that a bulb is formed in the first year and a flowering umbel in the second. 'Bolting', or premature flowering before bulb maturation, is an undesirable trait strongly selected against by breeders during adaptation of germplasm. To identify genome regions associated with adaptive traits we conducted linkage mapping and population genetic analyses of candidate genes, and QTL analysis of bolting using a low-density linkage map. We performed tagged amplicon sequencing of ten candidate genes, including the FT-like gene family, in eight diverse populations to identify polymorphisms and seek evidence of differentiation. Low nucleotide diversity and negative estimates of Tajima's D were observed for most genes, consistent with purifying selection. Significant population differentiation was observed only in AcFT2 and AcSOC1. Selective genotyping in a large 'Nasik Red × CUDH2150' F2 family revealed genome regions on chromosomes 1, 3 and 6 associated (LOD > 3) with bolting. Validation genotyping of two F2 families grown in two environments confirmed that a QTL on chromosome 1, which we designate AcBlt1, consistently conditions bolting susceptibility in this cross. The chromosome 3 region, which coincides with a functionally characterised acid invertase, was not associated with bolting in other environments, but showed significant association with bulb sucrose content in this and other mapping pedigrees. These putative QTL and candidate genes were placed on the onion map, enabling future comparative studies of adaptive traits.

Free vibrations of a pultruded GFRP frame with different rotational stiffnesses of bolted joints

NASA Astrophysics Data System (ADS)

Boscato, G.; Russo, S.

2013-01-01

Experimental and numerical results for the dynamic response of an all-FRP (fiber-reinforced polymer) twodimensional frame in free vibration are presented. The frame was assembled of pultruded glass-fiber-reinforced polymer (GFRP) profiles and bolted beam-to-column connections with GFRP angles. To give a variable rotational stiffness to the four beam-to-column major-axis joints, all bolts were tightened by a constant torque of 10, 25, or 40 N · m. Experimental measurements were performed on the three configurations to identify the natural frequencies of the first vibration mode in the plane of the frame and to determine the ability of each structure to dissipate the initial acceleration imposed on it through damping. The results obtained are compared with analytical and finite-element calculations. It was found that an increased bolt torque improved the dynamic response of the GFRP frame by reducing its vibration time and maximum displacements and by enhancing its dissipation capacity.

An analysis of roof bolter fatalities and injuries in U.S. mining

PubMed Central

Sammarco, J.J.; Podlesny, A.; Rubinstein, E.N.; Demich, B.

2017-01-01

Roof bolting typically follows the extraction of a commodity to help keep the roof from collapsing. During 2004 to 2013, roof bolter operators had the highest number of machinery-related injuries, accounting for 64.7 percent, at underground coal mines. This paper analyzes U.S. roof bolter fatal and nonfatal lost-time injury data at underground work locations for all commodities from 2004 through 2013 and determines risk indices for six roof bolting tasks. For fatal and nonfatal incidences combined, the roof bolting tasks in order of the highest to lowest risk index were bolting, handling of materials, setting the temporary roof support (TRS), drilling, tramming, and traversing. For fatalities, the roof bolting tasks in order of the highest to lowest risk index were handling of materials, setting the TRS, bolting, drilling, traversing, and tramming. Age was found to be a significant factor. Severity of injury, indicated by days lost, was found to increase with increasing age as well as with increasing experience, largely due to the confounding of age and experience. The operation of the roof bolting machine used in underground mining should be a research priority given the high frequency and severity of incidents. The results also suggest that temporal factors may exist, so additional research is warranted to better understand these factors and potentially develop interventions. This research provides a data-driven foundation from which future research can be conducted for safety interventions to reduce the frequency and severity of incidences involving the roof bolter activities of bolting, handling of materials, and setting the TRS. PMID:28845099

Development of engineering components having dual functionality

NASA Astrophysics Data System (ADS)

Thompson, L. D.; Waldbusser, R.; Pratt, E.

2000-05-01

This paper describes the engineering research and development of a smart aircraft bolt designed for high-tension wing attachment applications on USAF C-130 cargo planes. The bolt is a load-carrying structural component as well as serving as a damage sensor. The bolt material choice is TRIP (Transformation Induced Plasticity) steel; high-strength, metastable austenitic steel that gradually and irreversibly transforms to martensite during deformation. The martensite is ferromagnetic whereas the parent austenite phase is paramagnetic, having no significant ferromagnetic response. The ferromagnetic signature of the bolt can be correlated to the peak deformation strain and further correlated with the peak damage state. Stress-assisted phase transformations occur within the elastic regime while strain-induced transformations occur in the post-yield regime. Both transformation variants produce easily detected signals that can be readily monitored. A review of the nature of TRIP steel materials, their properties and behavior, and the smart bolt design approach is presented with examples of the quantitative output obtained during simulated laboratory testing. A brief discussion of the detection electronics and interrogation system is provided to familiarize the audience with the technical issues encompassing this technology. Preliminary results from field testing and service experience are reviewed.

Evaluation of different captive bolt lengths and breed influence upon post-stun hind limb and forelimb activity in fed cattle at a commercial slaughter facility.

PubMed

Martin, Miriam S; Kline, Helen C; Wagner, Dana R; Alexander, Lacey R; Edwards-Callaway, Lily N; Grandin, Temple

2018-05-03

The objective of this study was to assess the effects of captive bolt length and breed type on post-stun leg activity in cattle. A total of 2850 Holstein (HOL) and non-Holstein British/Continental bred (NHOL) steers and heifers were observed post-stunning at a large commercial slaughter facility. A pneumatically powered penetrating captive bolt stunner was used with three different bolt lengths: CON, 15.24 cm; MED, 16.51 cm; and LON, 17.78 cm. Hind limb kicking, forelimb activity, take away belt stops, carcass swing and number of knife sticks during exsanguination were recorded for each animal from video recording. Hind limb and forelimb kicks observed ranged from 0 to 25 and 0 to 8, respectively. Analysis of post-stun hind limb and forelimb activity indicated that increasing pneumatically powered penetrating captive bolt length does not decrease post-stun leg activity. There was a higher percentage of cattle experiencing take away belt stops and carcass swing in HOL as compared with NHOL. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Nonlinear Analysis of a Bolted Marine Riser Connector Using NASTRAN Substructuring

NASA Technical Reports Server (NTRS)

Fox, G. L.

1984-01-01

Results of an investigation of the behavior of a bolted, flange type marine riser connector is reported. The method used to account for the nonlinear effect of connector separation due to bolt preload and axial tension load is described. The automated multilevel substructing capability of COSMIC/NASTRAN was employed at considerable savings in computer run time. Simplified formulas for computer resources, i.e., computer run times for modules SDCOMP, FBS, and MPYAD, as well as disk storage space, are presented. Actual run time data on a VAX-11/780 is compared with the formulas presented.

Pilot cryo tunnel: Attachments, seals, and insulation

NASA Technical Reports Server (NTRS)

Wilson, J. F.; Ware, G. D.; Ramsey, J. W., Jr.

1974-01-01

Several different tests are described which simulated the actual configuration of a cryogenic wind tunnel operating at pressures up to 5 atmospheres (507 kPa) and temperatures from -320 F (78K) to 120 F (322K) in order to determine compatible bolting, adequate sealing, and effective insulating materials. The evaluation of flange attachments (continuous threaded studs) considered bolting based on compatible flanges, attachment materials, and prescribed bolt elongations. Various types of seals and seal configurations were studied to determine suitability and reusability under the imposed pressure and temperature loadings. The temperature profile was established for several materials used for structural supports.

Method for molding threads in graphite panels

DOEpatents

Short, William W.; Spencer, Cecil

1994-01-01

A graphite panel (10) with a hole (11) having a damaged thread (12) is repaired by drilling the hole (11) to remove all of the thread and make a new hole (13) of larger diameter. A bolt (14) with a lubricated thread (17) is placed in the new hole (13) and the hole (13) is packed with graphite cement (16) to fill the hole and the thread on the bolt. The graphite cement (16) is cured, and the bolt is unscrewed therefrom to leave a thread (20) in the cement (16) which is at least as strong as that of the original thread (12).

Behavior of single lap composite bolted joint under traction loading: Experimental investigation

NASA Astrophysics Data System (ADS)

Awadhani, L. V.; Bewoor, Anand

2018-04-01

Composite bolted joints are preferred connection in the composite structures to facilitate the dismantling for the replacements/ maintenance work. The joint behavior under tractive forces has been studied in order to understand the safety of the structure designed. The main objective of this paper is to investigate the behavior of single-lap joints in carbon fiber reinforced epoxy composites under traction loading conditions. The experiments were designed to identify the effect of bolt diameter, stacking sequence and loading rate on the properties of the joint. The experimental results show that the parameters influence the joint performance significantly.

49 CFR 572.86 - Test conditions and dummy adjustment.

Code of Federal Regulations, 2012 CFR

2012-10-01

... lying on a horizontal surface and the neck assembly mounted and shoulders on the edge of the surface... surface with the shoulders on the edge of the surface, mount the head and tighten the head bolt and nut... upper arm and tighten firmly the adjustment bolts for the shoulder joint with the upper arm placed in a...

49 CFR 572.86 - Test conditions and dummy adjustment.

Code of Federal Regulations, 2014 CFR

2014-10-01

... lying on a horizontal surface and the neck assembly mounted and shoulders on the edge of the surface... surface with the shoulders on the edge of the surface, mount the head and tighten the head bolt and nut... upper arm and tighten firmly the adjustment bolts for the shoulder joint with the upper arm placed in a...

49 CFR 572.86 - Test conditions and dummy adjustment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... lying on a horizontal surface and the neck assembly mounted and shoulders on the edge of the surface... surface with the shoulders on the edge of the surface, mount the head and tighten the head bolt and nut... upper arm and tighten firmly the adjustment bolts for the shoulder joint with the upper arm placed in a...

49 CFR 572.86 - Test conditions and dummy adjustment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... lying on a horizontal surface and the neck assembly mounted and shoulders on the edge of the surface... surface with the shoulders on the edge of the surface, mount the head and tighten the head bolt and nut... upper arm and tighten firmly the adjustment bolts for the shoulder joint with the upper arm placed in a...

49 CFR 572.86 - Test conditions and dummy adjustment.

Code of Federal Regulations, 2013 CFR

2013-10-01

... lying on a horizontal surface and the neck assembly mounted and shoulders on the edge of the surface... surface with the shoulders on the edge of the surface, mount the head and tighten the head bolt and nut... upper arm and tighten firmly the adjustment bolts for the shoulder joint with the upper arm placed in a...

KSC-2013-2342

NASA Image and Video Library

2013-05-13

CAPE CANAVERAL, Fla. -- At NASA’s Kennedy Space Center in Florida, workers move the Orion ground test vehicle, or GTA, into the Launch Equipment Test Facility, or LETF, from the Operations and Checkout Building. At the LETF, Lockheed Martin will put the GTA through a series of pyrotechnic bolt tests. The ground test vehicle is being used for path finding operations in the O&C, including simulated manufacturing and assembly procedures. Launching atop NASA's heavy-lift Space Launch System SLS, which also is under development, the Orion Multi-Purpose Crew Vehicle MPCV will serve as the exploration vehicle that will carry astronaut crews beyond low Earth orbit. It also will provide emergency abort capabilities, sustain the crew during space travel and provide safe re-entry from deep space return velocities. For more information, visit www.nasa.gov/orion. Photo credit: Jim Grossman

KSC-2013-2340

NASA Image and Video Library

2013-05-13

CAPE CANAVERAL, Fla. -- At NASA’s Kennedy Space Center in Florida, workers prepare to move the Orion ground test vehicle, or GTA, from the Operations and Checkout Building to the Launch Equipment Test Facility, or LETF. At the LETF, Lockheed Martin will put the GTA through a series of pyrotechnic bolt tests. The ground test vehicle is being used for path finding operations in the O&C, including simulated manufacturing and assembly procedures. Launching atop NASA's heavy-lift Space Launch System SLS, which also is under development, the Orion Multi-Purpose Crew Vehicle MPCV will serve as the exploration vehicle that will carry astronaut crews beyond low Earth orbit. It also will provide emergency abort capabilities, sustain the crew during space travel and provide safe re-entry from deep space return velocities. For more information, visit www.nasa.gov/orion. Photo credit: Jim Grossman

KSC-2013-2341

NASA Image and Video Library

2013-05-13

CAPE CANAVERAL, Fla. -- At NASA’s Kennedy Space Center in Florida, workers move the Orion ground test vehicle, or GTA, from the Operations and Checkout Building to the Launch Equipment Test Facility, or LETF. At the LETF, Lockheed Martin will put the GTA through a series of pyrotechnic bolt tests. The ground test vehicle is being used for path finding operations in the O&C, including simulated manufacturing and assembly procedures. Launching atop NASA's heavy-lift Space Launch System SLS, which also is under development, the Orion Multi-Purpose Crew Vehicle MPCV will serve as the exploration vehicle that will carry astronaut crews beyond low Earth orbit. It also will provide emergency abort capabilities, sustain the crew during space travel and provide safe re-entry from deep space return velocities. For more information, visit www.nasa.gov/orion. Photo credit: Jim Grossman

KSC-2013-2343

NASA Image and Video Library

2013-05-13

CAPE CANAVERAL, Fla. -- At NASA’s Kennedy Space Center in Florida, workers move the Orion ground test vehicle, or GTA, into the Launch Equipment Test Facility, or LETF, from the Operations and Checkout Building. At the LETF, Lockheed Martin will put the GTA through a series of pyrotechnic bolt tests. The ground test vehicle is being used for path finding operations in the O&C, including simulated manufacturing and assembly procedures. Launching atop NASA's heavy-lift Space Launch System SLS, which also is under development, the Orion Multi-Purpose Crew Vehicle MPCV will serve as the exploration vehicle that will carry astronaut crews beyond low Earth orbit. It also will provide emergency abort capabilities, sustain the crew during space travel and provide safe re-entry from deep space return velocities. For more information, visit www.nasa.gov/orion. Photo credit: Jim Grossman

46 CFR 98.30-27 - Connections.

Code of Federal Regulations, 2013 CFR

2013-10-01

... joints and couplings to make a tight seal; (2) Use a bolt in at least every other hole and in no case... (ANSI) standard flange coupling; (3) Use a bolt in each hole of couplings other than ANSI standard flange couplings; (4) Use a bolt in each hole of each permanently connected flange coupling; (5) Use...

46 CFR 98.30-27 - Connections.

Code of Federal Regulations, 2011 CFR

2011-10-01

... joints and couplings to make a tight seal; (2) Use a bolt in at least every other hole and in no case... (ANSI) standard flange coupling; (3) Use a bolt in each hole of couplings other than ANSI standard flange couplings; (4) Use a bolt in each hole of each permanently connected flange coupling; (5) Use...

46 CFR 98.30-27 - Connections.

Code of Federal Regulations, 2012 CFR

2012-10-01

... joints and couplings to make a tight seal; (2) Use a bolt in at least every other hole and in no case... (ANSI) standard flange coupling; (3) Use a bolt in each hole of couplings other than ANSI standard flange couplings; (4) Use a bolt in each hole of each permanently connected flange coupling; (5) Use...

30 CFR 56.3203 - Rock fixtures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... similar strata, opening dimensions and ground stresses in any mine; or (2) Have been tested and shown to... dimensions, and ground stresses as the area where the fixtures are expected to be used. During the test... the rock. (2) The torque of the first bolt, every tenth bolt, and the last bolt installed in each work...

30 CFR 56.3203 - Rock fixtures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... similar strata, opening dimensions and ground stresses in any mine; or (2) Have been tested and shown to... dimensions, and ground stresses as the area where the fixtures are expected to be used. During the test... the rock. (2) The torque of the first bolt, every tenth bolt, and the last bolt installed in each work...

46 CFR 98.30-27 - Connections.

Code of Federal Regulations, 2010 CFR

2010-10-01

... joints and couplings to make a tight seal; (2) Use a bolt in at least every other hole and in no case... (ANSI) standard flange coupling; (3) Use a bolt in each hole of couplings other than ANSI standard flange couplings; (4) Use a bolt in each hole of each permanently connected flange coupling; (5) Use...

The Nuts and Bolts of Michaelis-Menten Enzyme Kinetics: Suggestions and Clarifications

ERIC Educational Resources Information Center

Silverstein, Todd

2011-01-01

Matthew Junker's recent article describes a useful and effective enzyme kinetics application and analogy in which students simulate enzyme activity by unscrewing nut-bolt "substrate molecules", thus, converting them into separate nuts and bolts "products". A number of suggestions and corrections are presented that improve the clarity and accuracy…

Mechanical Behavior of CFRP Lattice Core Sandwich Bolted Corner Joints

NASA Astrophysics Data System (ADS)

Zhu, Xiaolei; Liu, Yang; Wang, Yana; Lu, Xiaofeng; Zhu, Lingxue

2017-12-01

The lattice core sandwich structures have drawn more attention for the integration of load capacity and multifunctional applications. However, the connection of carbon fibers reinforced polymer composite (CFRP) lattice core sandwich structure hinders its application. In this paper, a typical connection of two lattice core sandwich panels, named as corner joint or L-joint, was investigated by experiment and finite element method (FEM). The mechanical behavior and failure mode of the corner joints were discussed. The results showed that the main deformation pattern and failure mode of the lattice core sandwich bolted corner joints structure were the deformation of metal connector and indentation of the face sheet in the bolt holes. The metal connectors played an important role in bolted corner joints structure. In order to save the calculation resource, a continuum model of pyramid lattice core was used to replace the exact structure. The computation results were consistent with experiment, and the maximum error was 19%. The FEM demonstrated the deflection process of the bolted corner joints structure visually. So the simplified FEM can be used for further analysis of the bolted corner joints structure in engineering.

Methodology for Determining Limit Torques for Threaded Fasteners

NASA Technical Reports Server (NTRS)

Hissam, Andy

2011-01-01

In aerospace design, where minimizing weight is always a priority, achieving the full capacity from fasteners is essential. To do so, the initial bolt preload must be maximized. The benefits of high preload are well documented and include improved fatigue resistance, a stiffer joint, and resistance to loosening. But many factors like elastic interactions and embedment tend to lower the initial preload placed on the bolt. These factors provide additional motivation to maximize the initial preload. But, to maximize bolt preload, you must determine what torque to apply. Determining this torque is greatly complicated by the large preload scatter generally seen with torque control. This paper presents a detailed methodology for generating limit torques for threaded fasteners. This methodology accounts for the large scatter in preload found with torque control, and therefore, addresses the statistical nature of the problem. It also addresses prevailing torque, a feature common in aerospace fasteners. Although prevailing torque provides a desired locking feature, it can also increase preload scatter. In addition, it can limit the amount of preload that can be generated due to the torsion it creates in the bolt. This paper discusses the complications of prevailing torque and how best to handle it. A wide range of torque-tension bolt testing was conducted in support of this research. The results from this research will benefit the design engineer as well as analyst involved in the design of bolted joints, leading to better, more optimized structural designs.

A Reduced Order Model of Force Displacement Curves for the Failure of Mechanical Bolts in Tension.

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

Moore, Keegan J.; Sandia National Lab.; Brake, Matthew Robert

2015-12-01

Assembled mechanical systems often contain a large number of bolted connections. These bolted connections (joints) are integral aspects of the load path for structural dynamics, and, consequently, are paramount for calculating a structure's stiffness and energy dissipation prop- erties. However, analysts have not found the optimal method to model appropriately these bolted joints. The complexity of the screw geometry causes issues when generating a mesh of the model. This report will explore different approaches to model a screw-substrate connec- tion. Model parameters such as mesh continuity, node alignment, wedge angles, and thread to body element size ratios are examined. Themore » results of this study will give analysts a better understanding of the influences of these parameters and will aide in finding the optimal method to model bolted connections.« less

9 CFR 313.15 - Mechanical; captive bolt.

Code of Federal Regulations, 2014 CFR

2014-01-01

... instruments on detonation deliver bolts of varying diameters and lengths through the skull and into the brain. Unconsciousness is produced immediately by physical brain destruction and a combination of changes in intracranial... a flattened circular head against the external surface of the animal's head over the brain. Diameter...

9 CFR 313.15 - Mechanical; captive bolt.

Code of Federal Regulations, 2013 CFR

2013-01-01

... instruments on detonation deliver bolts of varying diameters and lengths through the skull and into the brain. Unconsciousness is produced immediately by physical brain destruction and a combination of changes in intracranial... a flattened circular head against the external surface of the animal's head over the brain. Diameter...

9 CFR 313.15 - Mechanical; captive bolt.

Code of Federal Regulations, 2012 CFR

2012-01-01

... instruments on detonation deliver bolts of varying diameters and lengths through the skull and into the brain. Unconsciousness is produced immediately by physical brain destruction and a combination of changes in intracranial... a flattened circular head against the external surface of the animal's head over the brain. Diameter...

Technology of research of hydroturbine unit work using seismic methods

NASA Astrophysics Data System (ADS)

Seleznev, V. S.; Liseikin, A. V.; Gromyko, P. V.; Soloviev, V. M.

2013-05-01

On August, 17, 2009 one of the most significant accident in hydropower engineering was happened at Sayano-Shushenskaya Hydroelectric Power Station. Specialists of Geophysical Survey SB RAS took part in the State Committee on investigation of the accident cause at Sayano-Shushenskaya HPS. It was determined, that the cause of the accident was a break of stud-bolts on the turbine cover. Why stud-bolts did not stand a load? There were assumptions that hydraulic shock provoked the accident. But, if it is so, seismic station "Cheremushky", situated in 4 km away from the HPS, should has a record of this event. First of all, investigating the record, got at the seismic station in the moment of the accident, it was determined that strength of seismic waves, recorded at the moment of the accident, did not exceed strength of waves got at trotyl explosion of 500 g at a distance to 4 km. The version of hydraulic shock was not proved. There were distinguished low-frequency oscillations and it was determined that the hydroturbine unit (HU) had been raised up more then 10 m in height for 10 sec. Analyzing the seismic station records during the period of more than a year before the accident and records of operating modes of different HU, there was determined that oscillations radiated by second (damaged) HU were approximately 1.5 times more intense than oscillations from all other HU. After the accident at Sayano-Shushenskaya HPS hydroturbine units were started in turns: at first there were started hydroturbine units of old construction (3, 4, 5, 6), then HP of new construction (1, 7, 8, 9). We installed 10 - 15 three-component seismic stations in different points around a HU and studied field of seismic oscillations from it's work. It was determined, that HU radiates a set of monochromatic oscillations divisible by speed of rotation equal to 2.381 Hz. Change of these signals amplitude is connected with change of HU operation modes. Research of changes in oscillations spectral distribution in time allows to control HU work and it's technical condition. It was determined, that natural frequency of turbine cover (when water entry is closed) has several maximums, and it is situated in the range of 60 - 110 Hz. Power radiation of monochromatic signals is registered in the same range from old hydroturbine units when they work, especially on double blade frequency equal to 76.2 Hz. It turns out that the turbine cover and fixed it stud-bolts were in condition of constant resonance excitation during work of HU. Since second HU was arranged in such a way that oscillations radiated by it exceeded oscillations from other aggregates, the accident occurred exactly on this HU. The real cause of the accident is connected with the fact that at calculation of the turbine cover fastening it was not taken into account the fact that it would work in constant resonance excitation. On new constructed HU number of stud-bolts was increased and the amplitude of monochromatic oscillations was considerably reduced.

Impact of Rainfall on Multilane Roundabout Flowrate Contraction

NASA Astrophysics Data System (ADS)

PARKSHIR, Amir; BEN-EDIGBE, Johnnie

2017-08-01

In this study, roundabouts at two sites in the Malaysia were investigated under rainy and dry weather conditions. Two automatic traffic counters per roundabout arm as well as two rain gauge stations were used to collect data at each surveyed site. Nearly one million vehicles were investigated at four sites. Vehicle volume, speeds and headways for entry and circulating flows were collected continuously at each roundabout about arm for six weeks between November 2013 and January 2014. Empirical regression technique and gap-acceptance models were modified and used to analyze roundabout capacity. Good fits to the data were obtained; the results also fit models developed in other countries. It was assumed that entry capacity depends on the geometric characteristics of the roundabout, particularly the diameter of the outside circle of the intersection. It was also postulated that geometric characteristics determine the speed of vehicles around the central island and, therefore, have an impact on the gap-acceptance process and consequently the capacity. Only off-peak traffic data per light, moderate or heavy rainfall were analysed. Peak traffic data were not used because of the presence of peak traffic flow. Passenger car equivalent values being an instrument of conversion from traffic volume to flow were modified. Results show that, average entry capacity loss is about 22.6% under light rainfall, about 18.1% under moderate rainfall and about 5.6% under heavy rainfall. Significant entry capacity loss would result from rainfall irrespective of their intensity. It can be postulated that entry capacity loss under heavy rainfall is lowest because the advantage enjoyed by circulating flow would be greatly reduced with increased rainfall intensity. The paper concluded that rainfall has significant impact of flowrate contraction at roundabouts.

NUTS and BOLTS: Applications of Fluorescence Detected Sedimentation

PubMed Central

Kroe, Rachel R.; Laue, Thomas M.

2008-01-01

Analytical ultracentrifugation is a widely used method for characterizing the solution behavior of macromolecules. However, the two commonly used detectors (absorbance and interference) impose some fundamental restrictions on the concentrations and complexity of the solutions that can be analyzed. The recent addition of a fluorescence detector for the XL-I analytical ultracentrifuge (AU-FDS) enables two different types of sedimentation experiments. First, the AU-FDS can detect picomolar concentrations of labeled solutes allowing the characterization of very dilute solutions of macromolecules, applications we call Normal Use Tracer Sedimentation (NUTS). The great sensitivity of NUTS analysis allows the characterization of small quantities of materials and high affinity interactions. Second, AU-FDS allows characterization of trace quantities of labeled molecules in solutions containing high concentrations and complex mixtures of unlabeled molecules, applications we call Biological On Line Tracer Sedimentation (BOLTS). The discrimination of BOLTS enables the size distribution of a labeled macromolecule to be determined in biological milieu such as cell lysates and serum. Examples are presented that embody features of both NUTS and BOLTS applications, along with our observations on these applications. PMID:19103145

An ultrasonic technique for measuring stress in fasteners

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

Stevens, K. J.; Day, P.; Byron, D.

1999-12-02

High temperature bolting alloys are extensively used in the thermal power generation industry as for example, reheat ESV and Governor valve studs. Remnant life assessment methodologies and plant maintenance procedures require the monitoring of the operational stress levels in these fasteners. Some conventional ultrasonic techniques require longitudinal wave measurements to be undertaken when the nut on the bolt is loosened and then re-tightened. Other techniques use a combination of shear waves and longitudinal waves. In this paper, the problems and pitfalls associated with various ultrasonic techniques for measuring stress in bolts, is discussed. An ultrasonic technique developed for measuring themore » stress in Durehete 1055 bolts is presented. Material from a textured rolled bar has been used as a test bed in the development work. The technique uses shear wave birefringence and compression waves at several frequencies to measure texture, fastener length and the average stress. The technique was developed by making ultrasonic measurements on bolts tensioned in universal testing machines and a hydraulic nut. The ultrasonic measurements of residual stress have been checked against strain gauge measurements. The Durehete bolts have a hollow cylinder geometry of restricted dimensions, which significantly alters compression and shear wave velocities from bulk values and introduces hoop stresses which can be measured by rotating the polarization of the shear wave probe. Modelling of the experimental results has been undertaken using theories for the elastic wave propagation through waveguides. The dispersion equations allow the velocity and length of the fastener to be measured ultrasonically in some situations where the length of the fastener can not be measured directly with a vernier caliper or micrometer and/or where it is undesirable to loosen nuts to take calibration readings of the shear and compression wave velocities.« less

Automatic segmentation of stereoelectroencephalography (SEEG) electrodes post-implantation considering bending.

PubMed

Granados, Alejandro; Vakharia, Vejay; Rodionov, Roman; Schweiger, Martin; Vos, Sjoerd B; O'Keeffe, Aidan G; Li, Kuo; Wu, Chengyuan; Miserocchi, Anna; McEvoy, Andrew W; Clarkson, Matthew J; Duncan, John S; Sparks, Rachel; Ourselin, Sébastien

2018-06-01

The accurate and automatic localisation of SEEG electrodes is crucial for determining the location of epileptic seizure onset. We propose an algorithm for the automatic segmentation of electrode bolts and contacts that accounts for electrode bending in relation to regional brain anatomy. Co-registered post-implantation CT, pre-implantation MRI, and brain parcellation images are used to create regions of interest to automatically segment bolts and contacts. Contact search strategy is based on the direction of the bolt with distance and angle constraints, in addition to post-processing steps that assign remaining contacts and predict contact position. We measured the accuracy of contact position, bolt angle, and anatomical region at the tip of the electrode in 23 post-SEEG cases comprising two different surgical approaches when placing a guiding stylet close to and far from target point. Local and global bending are computed when modelling electrodes as elastic rods. Our approach executed on average in 36.17 s with a sensitivity of 98.81% and a positive predictive value (PPV) of 95.01%. Compared to manual segmentation, the position of contacts had a mean absolute error of 0.38 mm and the mean bolt angle difference of [Formula: see text] resulted in a mean displacement error of 0.68 mm at the tip of the electrode. Anatomical regions at the tip of the electrode were in strong concordance with those selected manually by neurosurgeons, [Formula: see text], with average distance between regions of 0.82 mm when in disagreement. Our approach performed equally in two surgical approaches regardless of the amount of electrode bending. We present a method robust to electrode bending that can accurately segment contact positions and bolt orientation. The techniques presented in this paper will allow further characterisation of bending within different brain regions.

77 FR 66769 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbojet Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

.... (5) If any bolt is found broken in the HPT shaft air seal sleeve, inspect the HPT stage 1 disc for...) bearing support assembly and HPT air seal sleeve bolts identified that, before installation, those bolts... assembly, high-pressure turbine (HPT) bearing support assembly, and HPT air seal sleeve. (2) If engine...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

Simulated sawing of squares: a tool to improve wood utilization

Treesearch

R. Bruce Anderson; Hugh W. Reynolds

1981-01-01

Manufacturers of turning squares have had difficulty finding the best combination of bolt and square sizes for producing squares most efficiently. A computer simulation technique has been developed for inexpensively detemining the best combination of bolt and square size. Ranges of bolt dimeters to achieve a stated level of yield are given. The manufacturer can choose...

9 CFR 313.15 - Mechanical; captive bolt.

Code of Federal Regulations, 2010 CFR

2010-01-01

... slaughtering of sheep, swine, goats, calves, cattle, horses, mules, and other equines by using captive bolt... regard to kind, breed, size, age, and sex of the animal to produce the desired results. (2) Special... varies, depending on kind, breed, size, age, and sex of the animal. Young swine, lambs, and calves...

9 CFR 313.15 - Mechanical; captive bolt.

Code of Federal Regulations, 2011 CFR

2011-01-01

... slaughtering of sheep, swine, goats, calves, cattle, horses, mules, and other equines by using captive bolt... regard to kind, breed, size, age, and sex of the animal to produce the desired results. (2) Special... varies, depending on kind, breed, size, age, and sex of the animal. Young swine, lambs, and calves...

77 FR 32698 - Proposed Extension of Existing Information Collection; Safety Standards for Roof Bolts in Metal...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-01

... with the Paperwork Reduction Act of 1995. This program helps to assure that requested data can be... approved this information collection request on September 28, 2009. The package expires on September 30... standards related to the integrity of roof bolts. MSHA has updated the data for the number of respondents...

Reusable Solid Rocket Motor Nozzle Joint 5 Redesign

NASA Technical Reports Server (NTRS)

Lui, R. C.; Stratton, T. C.; LaMont, D. T.

2003-01-01

Torque tension testing of a newly designed Reusable Solid Rocket Motor nozzle bolted assembly was successfully completed. Test results showed that the 3-sigma preload variation was as expected at the required input torque level and the preload relaxation were within the engineering limits. A shim installation technique was demonstrated as a simple process to fill a shear lip gap between nozzle housings in the joint region. A new automated torque system was successfully demonstrated in this test. This torque control tool was found to be very precise and accurate. The bolted assembly performance was further evaluated using the Nozzle Structural Test Bed. Both current socket head cap screw and proposed multiphase alloy bolt configurations were tested. Results indicated that joint skip and bolt bending were significantly reduced with the new multiphase alloy bolt design. This paper summarizes all the test results completed to date.

Energy value of paraquat-treated and resin-soaked lobolly pine

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

Kossuth, S.V.; Roberts, D.R.; Huffman, J.B.

1984-07-01

With a basal injector, loblolly pines were treated with 5% paraquat cation (weight/weight basis) and harvested after 18 months. The resin acid, turpentine, moisture content (MC) and energy value were measured in three bolts of the stem. In bolt 1, the first 152 cm above the injection site, the increase in resin acids was 392% and in turpentine, 564%. Within the whole stem (the first two 152 cm bolts and the third bolt to a 7.6 cm inside-bark diameter) resin acids and turpentine increased 203 and 296% respectively. Moisture content was reduced 9%, 8%, and 8% in bolts 1, 2more » and 3, respectively. Turpentine from treated and untreated trees had an average heating value of 19,369 cal/g. When weighted for volume, net energy content was 7.8% greater for treated than control trees because of the increase in resin, including turpentine and the lowered MC.« less

Efficient Streaming Mass Spatio-Temporal Vehicle Data Access in Urban Sensor Networks Based on Apache Storm

PubMed Central

Zhou, Lianjie; Chen, Nengcheng; Chen, Zeqiang

2017-01-01

The efficient data access of streaming vehicle data is the foundation of analyzing, using and mining vehicle data in smart cities, which is an approach to understand traffic environments. However, the number of vehicles in urban cities has grown rapidly, reaching hundreds of thousands in number. Accessing the mass streaming data of vehicles is hard and takes a long time due to limited computation capability and backward modes. We propose an efficient streaming spatio-temporal data access based on Apache Storm (ESDAS) to achieve real-time streaming data access and data cleaning. As a popular streaming data processing tool, Apache Storm can be applied to streaming mass data access and real time data cleaning. By designing the Spout/bolt workflow of topology in ESDAS and by developing the speeding bolt and other bolts, Apache Storm can achieve the prospective aim. In our experiments, Taiyuan BeiDou bus location data is selected as the mass spatio-temporal data source. In the experiments, the data access results with different bolts are shown in map form, and the filtered buses’ aggregation forms are different. In terms of performance evaluation, the consumption time in ESDAS for ten thousand records per second for a speeding bolt is approximately 300 milliseconds, and that for MongoDB is approximately 1300 milliseconds. The efficiency of ESDAS is approximately three times higher than that of MongoDB. PMID:28394287

Efficient Streaming Mass Spatio-Temporal Vehicle Data Access in Urban Sensor Networks Based on Apache Storm.

PubMed

Zhou, Lianjie; Chen, Nengcheng; Chen, Zeqiang

2017-04-10

The efficient data access of streaming vehicle data is the foundation of analyzing, using and mining vehicle data in smart cities, which is an approach to understand traffic environments. However, the number of vehicles in urban cities has grown rapidly, reaching hundreds of thousands in number. Accessing the mass streaming data of vehicles is hard and takes a long time due to limited computation capability and backward modes. We propose an efficient streaming spatio-temporal data access based on Apache Storm (ESDAS) to achieve real-time streaming data access and data cleaning. As a popular streaming data processing tool, Apache Storm can be applied to streaming mass data access and real time data cleaning. By designing the Spout/bolt workflow of topology in ESDAS and by developing the speeding bolt and other bolts, Apache Storm can achieve the prospective aim. In our experiments, Taiyuan BeiDou bus location data is selected as the mass spatio-temporal data source. In the experiments, the data access results with different bolts are shown in map form, and the filtered buses' aggregation forms are different. In terms of performance evaluation, the consumption time in ESDAS for ten thousand records per second for a speeding bolt is approximately 300 milliseconds, and that for MongoDB is approximately 1300 milliseconds. The efficiency of ESDAS is approximately three times higher than that of MongoDB.

75 FR 1297 - Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, -900, and -900ER Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-11

... installed, one-time torquing of the nut and bolt, and corrective actions if necessary. This proposed AD... nut and bolt, and corrective actions if necessary. That AD resulted from reports of parts coming off... of the slat track hardware (i.e., the bolt, washers, downstops, stop location, and nut shown in...

What Makes Usain Bolt Unique as a Sprinter?

ERIC Educational Resources Information Center

Shinabargar, A. J.; Hellrich, Matt; Baker, Blane

2010-01-01

For both casual and avid fans alike, Olympic and other sporting events can provide a wealth of data for simple physics analyses. One of the most impressive performances in recent Olympic history is that of Usain Bolt in the track-and-field sprinting events during the 2008 Summer Games. Over a seven-day span, Bolt set world records in the 100-m and…

Shape memory alloy-based moment connections with superior self-centering properties

NASA Astrophysics Data System (ADS)

Farmani, Mohammad Amin; Ghassemieh, Mehdi

2016-07-01

Superelastic shape memory alloys (SMAs) have the potential to create a spontaneous recentering mechanism on the connections of a structural system under seismic actions, which results in mitigation of the damage in the main structural members. In this article, innovative types of steel beam-to-column moment connections incorporating SMA bolts and plates are introduced and studied through a numerical approach. First, SMA bolted end-plate connection model is produced and analyzed by means of the finite element method to validate the numerical analysis against the prior experimental results. Then, the performance of eleven different end-plate moment connection models subjected to cyclic loading is investigated. By selecting the lower values for the moment capacity based on bolts strength in comparison to the flexural resistance of the beam, the plastic hinge is transferred from the beam section to the beam-column interface. Hence, employing superelastic materials at the connection interface could be potentially effective in providing the desired self-centering effect in the connection. To this end, the impact of utilizing superelastic SMA bolts and end-plates instead of using the conventional structural steel on the overall cyclic response of the connections is evaluated in this study. Results show that extended end-plate connections equipped with SMA bolts and end-plates, if properly proportioned and detailed, not only exhibit a clear reduction in the residual drifts after a seismic event, but also can meet the ductility requirements with good energy dissipation and sufficient stiffness.

Solid Rocket Booster Hydraulic Pump Port Cap Joint Load Testing

NASA Technical Reports Server (NTRS)

Gamwell, W. R.; Murphy, N. C.

2004-01-01

The solid rocket booster uses hydraulic pumps fabricated from cast C355 aluminum alloy, with 17-4 PH stainless steel pump port caps. Corrosion-resistant steel, MS51830 CA204L self-locking screw thread inserts are installed into C355 pump housings, with A286 stainless steel fasteners installed into the insert to secure the pump port cap to the housing. In the past, pump port cap fasteners were installed to a torque of 33 Nm (300 in-lb). However, the structural analyses used a significantly higher nut factor than indicated during tests conducted by Boeing Space Systems. When the torque values were reassessed using Boeing's nut factor, the fastener preload had a factor of safety of less than 1, with potential for overloading the joint. This paper describes how behavior was determined for a preloaded joint with a steel bolt threaded into steel inserts in aluminum parts. Finite element models were compared with test results. For all initial bolt preloads, bolt loads increased as external applied loads increased. For higher initial bolt preloads, less load was transferred into the bolt, due to external applied loading. Lower torque limits were established for pump port cap fasteners and additional limits were placed on insert axial deformation under operating conditions after seating the insert with an initial preload.

LCM-seq reveals the crucial role of LsSOC1 in heat-promoted bolting of lettuce (Lactuca sativa L.).

PubMed

Chen, Zijing; Zhao, Wensheng; Ge, Danfeng; Han, Yingyan; Ning, Kang; Luo, Chen; Wang, Shenglin; Liu, Renyi; Zhang, Xiaolan; Wang, Qian

2018-05-17

Lettuce (Lactuca sativa L.) is one of the most economically important vegetables. The floral transition in lettuce is accelerated under high temperatures, which can significantly decrease yields. However, the molecular mechanism underlying the floral tranition in lettuce is poorly known. Using laser capture microdissection coupled with RNA sequencing, we isolated shoot apical meristem cells from the bolting-sensitive lettuce line S39 at four critical stages of development. Subsequently, we screened specifically for the flowering-related gene LsSOC1 during the floral transition through comparative transcriptomic analysis. Molecular biology, developmental biology, and biochemical tools were combined to investigate the biological function of LsSOC1 in lettuce. LsSOC1 knockdown by RNA interference resulted in a significant delay in the timing of bolting and insensitivity to high temperature, which indicated that LsSOC1 functions as an activator during heat-promoted bolting in lettuce. We determined that two heat-shock transcription factors, HsfA1e and HsfA4c, bound to the promoter of LsSOC1 to confirm that LsSOC1 played an important role in heat-promoted bolting. This study indicates that LsSOC1 plays a crucial role in the heat-promoted bolting process in lettuce. Further investigation of LsSOC1 may be useful for clarification of the bolting mechanism in lettuce. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Standard specification for anchor bolts, steel, 36, 55, and 105-ksi yield strength. ASTM standard

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

NONE

1998-07-01

This specification is under the jurisdiction of ASTM Committee F-16 on Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts, Nuts, Rivets, and Washers. Current edition approved Dec. 10, 1997 and published July 1998. Originally published as F 1554-94. Last previous edition was F 1554-94.

The Problem with "Nuts and Bolts:" How the Emphasis on "Highly Qualified Professionals" Is Undermining Education

ERIC Educational Resources Information Center

Swain, Amy

2013-01-01

Schools of education have seen many changes over the last 100 years (Labaree 2004). More recent modifications have included the slow and steady elimination of the social foundations of education in lieu of a more direct attention to teacher skills and basic training. The increased focus on the so-called "nuts and bolts" of teacher…

Literature Review on the Design of Composite Mechanically Fastened Joints (Revue de la Documentation sur la Conception des Joints a Liaison Mecanique en Composites),

DTIC Science & Technology

1986-02-01

mechanics Eisenmann (32) established a bolted joint static strength prediction model based on fracture mechanics for composite materials. The failure...34 Composite Materials, Volume 2, Academic Press, 1974, pp. 353-431. 32. Eisenmann , J.R., "Bolted Joint Static Strength Model for Composite Materials," NASA

Evaluation of methods for the euthanasia of cattle in a foreign animal disease outbreak.

PubMed Central

Baker, H J; Scrimgeour, H J

1995-01-01

In anticipation of the need to euthanize large numbers of cattle in the event of a foreign animal disease outbreak, two models of captive bolt gun and various firearms and ammunition loads were tested in order to assess their suitability. In the first phase of the project, two models of captive bolt stunner were used in an abattoir, and assessed for effectiveness. In the second phase, several firearms and ammunition were used on isolated bovine heads and assessed for effectiveness. Little difference was found between the two captive bolt stunners. Of the firearms and ammunition evaluated, the Ruger Mini-14 and the Core-Shot round, a prefragmented projectile, were determined to be most suitable. In situations where large herds of livestock are to be depopulated, and where the restraint required for the use of captive bolt stunners is not practical, there are commercially available firearms and ammunition that are suitable for this purpose. PMID:7757921

A loose bolt delays loading of Endeavour's external tank

NASA Technical Reports Server (NTRS)

2000-01-01

This loose bracket, observed hanging down from the side of the White Room at Launch Pad 39B, delayed loading of Endeavour's external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.

Eddy-Current Detection of Weak Bolt Heads

NASA Technical Reports Server (NTRS)

Messina, C. P.

1987-01-01

Electronic test identifies flawed units passing hardness tests. Eddy-current test detects weakness in head-to-shank junctions of 1/4-28 cup-washer lock bolts. Developed for alloy A286 steel bolts in Space Shuttle main engine fuel turbo-pump. Test examines full volume of head, including head-to-shank transition and nondestructively screens out potentially defective units. Test adapts to any other alloys.

KSC-07pd2717

NASA Image and Video Library

2007-10-08

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Doug Wheelock has his helmet fitted on his launch and entry suit, preparing for launch. The fitting is part of terminal countdown demonstration test, or TCDT, activities the crew is undertaking at NASA's Kennedy Space Center. The TCDT also includes emergency egress procedures, equipment familiarization and a simulated launch countdown. Mission STS-120, which will carry the Italian-built U.S. Node 2 to the International Space Station, is targeted for launch on Oct. 23. Photo credit: NASA/Kim Shiflett

KSC-07pd2718

NASA Image and Video Library

2007-10-08

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Paolo Nespoli has his helmet fitted on his launch and entry suit, preparing for launch. The fitting is part of terminal countdown demonstration test, or TCDT, activities the crew is undertaking at NASA's Kennedy Space Center. The TCDT also includes emergency egress procedures, equipment familiarization and a simulated launch countdown. Mission STS-120, which will carry the Italian-built U.S. Node 2 to the International Space Station, is targeted for launch on Oct. 23. Photo credit: NASA/Kim Shiflett

Tunnel Point Cloud Filtering Method Based on Elliptic Cylindrical Model

NASA Astrophysics Data System (ADS)

Zhua, Ningning; Jiaa, Yonghong; Luo, Lun

2016-06-01

The large number of bolts and screws that attached to the subway shield ring plates, along with the great amount of accessories of metal stents and electrical equipments mounted on the tunnel walls, make the laser point cloud data include lots of non-tunnel section points (hereinafter referred to as non-points), therefore affecting the accuracy for modeling and deformation monitoring. This paper proposed a filtering method for the point cloud based on the elliptic cylindrical model. The original laser point cloud data was firstly projected onto a horizontal plane, and a searching algorithm was given to extract the edging points of both sides, which were used further to fit the tunnel central axis. Along the axis the point cloud was segmented regionally, and then fitted as smooth elliptic cylindrical surface by means of iteration. This processing enabled the automatic filtering of those inner wall non-points. Experiments of two groups showed coincident results, that the elliptic cylindrical model based method could effectively filter out the non-points, and meet the accuracy requirements for subway deformation monitoring. The method provides a new mode for the periodic monitoring of tunnel sections all-around deformation in subways routine operation and maintenance.

Relationship of physical fitness test results and hockey playing potential in elite-level ice hockey players.

PubMed

Burr, Jaime F; Jamnik, Roni K; Baker, Joseph; Macpherson, Alison; Gledhill, Norman; McGuire, E J

2008-09-01

The primary purpose of this study was to determine the fitness variables with the highest capability for predicting hockey playing potential at the elite level as determined by entry draft selection order. We also examined the differences associated with the predictive abilities of the test components among playing positions. The secondary purpose of this study was to update the physiological profile of contemporary hockey players including positional differences. Fitness test results conducted by our laboratory at the National Hockey League Entry Draft combine were compared with draft selection order on a total of 853 players. Regression models revealed peak anaerobic power output to be important for higher draft round selection in all positions; however, the degree of importance of this measurement varied with playing position. The body index, which is a composite score of height, lean mass, and muscular development, was similarly important in all models, with differing influence by position. Removal of the goalies' data increased predictive capacity, suggesting that talent identification using physical fitness testing of this sort may be more appropriate for skating players. Standing long jump was identified as a significant predictor variable for forwards and defense and could be a useful surrogate for assessing overall hockey potential. Significant differences exist between the physiological profiles of current players based on playing position. There are also positional differences in the relative importance of anthropometric and fitness measures of off-ice hockey tests in relation to draft order. Physical fitness measures and anthropometric data are valuable in helping predict hockey playing potential. Emphasis on anthropometry should be used when comparing elite-level forwards, whereas peak anaerobic power and fatigue rate are more useful for differentiating between defense.

Correlative controls of senescence and plant death in Arabidopsis thaliana (Brassicaceae).

PubMed

Noodén, L D; Penney, J P

2001-11-01

Like most monocarpic plants, longevity of Arabidopsis thaliana plants is controlled by the reproductive structures; however, they appear to work differently from most dicots studied. Neither male- and female-sterility mutations (ms1-1 and bell1, respectively) nor surgical removal of the stems with inflorescences (bolts) at various stages significantly increased the longevity of individual rosette leaves, yet the mutants and treated plants lived 20-50 d longer, measured by the death of the last rosette and/or the last cauline leaf. A series of growth mutations (clv2-4, clv3-2, det3, vam1 enh, and dark green) also increased plant longevity by 20-30 d but did not delay the overall development of the plants. The mutations prolonged plant life through the production of new leaves and stems with inflorescences (bolts) rather than by extending leaf longevity. In growing stems, the newly-formed leaves may induce senescence in the older leaves; however, removal of the younger leaves did not significantly increase the life of the older leaves on the compressed stems of Arabidopsis. Since plants that produce more bolts also live longer, the reproductive load (dry weight) of the bolts did not seem to drive leaf or whole plant senescence here. The developing reproductive structures caused the death of the plant by preventing regeneration of leaves and bolts, which are green and presumably photosynthetic. They also exerted a correlative control (repression) on the development of additional reproductive structures.

A redox-mediated modulation of stem bolting in transgenic Nicotiana sylvestris differentially expressing the external mitochondrial NADPH dehydrogenase.

PubMed

Liu, Yun-Jun; Nunes-Nesi, Adriano; Wallström, Sabá V; Lager, Ida; Michalecka, Agnieszka M; Norberg, Fredrik E B; Widell, Susanne; Fredlund, Kenneth M; Fernie, Alisdair R; Rasmusson, Allan G

2009-07-01

Cytosolic NADPH can be directly oxidized by a calcium-dependent NADPH dehydrogenase, NDB1, present in the plant mitochondrial electron transport chain. However, little is known regarding the impact of modified cytosolic NADPH reduction levels on growth and metabolism. Nicotiana sylvestris plants overexpressing potato (Solanum tuberosum) NDB1 displayed early bolting, whereas sense suppression of the same gene led to delayed bolting, with consequential changes in flowering time. The phenotype was dependent on light irradiance but not linked to any change in biomass accumulation. Whereas the leaf NADPH/NADP(+) ratio was unaffected, the stem NADPH/NADP(+) ratio was altered following the genetic modification and strongly correlated with the bolting phenotype. Metabolic profiling of the stem showed that the NADP(H) change affected relatively few, albeit central, metabolites, including 2-oxoglutarate, glutamate, ascorbate, sugars, and hexose-phosphates. Consistent with the phenotype, the modified NDB1 level also affected the expression of putative floral meristem identity genes of the SQUAMOSA and LEAFY types. Further evidence for involvement of the NADPH redox in stem development was seen in the distinct decrease in the stem apex NADPH/NADP(+) ratio during bolting. Additionally, the potato NDB1 protein was specifically detected in mitochondria, and a survey of its abundance in major organs revealed that the highest levels are found in green stems. These results thus strongly suggest that NDB1 in the mitochondrial electron transport chain can, by modifying cell redox levels, specifically affect developmental processes.

Analysis of a Preloaded Bolted Joint in a Ceramic Composite Combustor

NASA Technical Reports Server (NTRS)

Hissam, D. Andy; Bower, Mark V.

2003-01-01

This paper presents the detailed analysis of a preloaded bolted joint incorporating ceramic materials. The objective of this analysis is to determine the suitability of a joint design for a ceramic combustor. The analysis addresses critical factors in bolted joint design including preload, preload uncertainty, and load factor. The relationship between key joint variables is also investigated. The analysis is based on four key design criteria, each addressing an anticipated failure mode. The criteria are defined in terms of margin of safety, which must be greater than zero for the design criteria to be satisfied. Since the proposed joint has positive margins of safety, the design criteria are satisfied. Therefore, the joint design is acceptable.

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SEISMIC ANALYSIS IN SUPPORT OF INCREASED LIQUID LEVEL IN 241-AP TANK FARMS

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

TC MACKEY; FG ABATT; MW RINKER

2009-01-14

The essential difference between Revision 1 and the original issue of this report is in the spring constants used to model the anchor bolt response for the anchor bolts that tie the steel dome of the primary tank to the concrete tank dome. Consequently, focus was placed on the changes in the anchor bolt responses, and a full reevaluation of all tank components was judged to be unnecessary. To confirm this judgement, primary tank stresses from the revised analysis of the BES-BEC case are compared to the original analysis and it was verified that the changes are small, as expected.

Corrosion Behavior of Sacrificial Coatings on Grade 10.9 Fasteners for Multimetal Armor Applications

DTIC Science & Technology

2013-08-01

hexavalent chromium , immersion, magniplate, trivalent chromium (TCP), bolts nonchromate, hexavalent chrome, grade 10.9 fasteners, bolt-on armor...for Testing and Materials (ASTM) B633 (4) electroplated zinc with hexavalent chromium conversion coating 2. Trivalent Chromium Process (TCP): ASTM...B633 (4) electroplated zinc with trivalent chromium conversion coating 3. AlumiPlate: Process details, entire surface electroplated with aluminum (Al

Design of Multiple Bolted Connections for Laminated Veneer Lumber

Treesearch

Borjen Yeh; Douglas Rammer; Jeff Linville

2014-01-01

The design of multiple bolted connections in accordance with Appendix E of the National Design Specification for Wood Construction (NDS) has incorporated provisions for evaluating localized member failure modes of row and group tear-out when the connections are closely spaced. Originally based on structural glued laminated timber (glulam) members made with all L1...

A Hands-On Classroom Simulation to Demonstrate Concepts in Enzyme Kinetics

ERIC Educational Resources Information Center

Junker, Matthew

2010-01-01

A classroom exercise is described to introduce enzyme kinetics in an undergraduate biochemistry or chemistry course. The exercise is a simulation in which a student acts as an enzyme that "catalyzes" the unscrewing of a nut from a bolt. With other students assisting, the student enzyme carries out reactions with bolt-nut substrates under different…

33 CFR Appendix A to Part 155 - Specifications for Shore Connection

Code of Federal Regulations, 2013 CFR

2013-07-01

... of this part] Item Description Dimension 1 Outside diameter 215 mm. (8 in.). 2 Inside diameter According to pipe outside diameter. 3 Bolt circle diameter 183 mm. (7 3/16 in.). 4 Slots in flange 6 holes 22 mm. (7/8 in.) in diameter shall be equidistantly placed on a bolt circle of the above diameter...

33 CFR Appendix A to Part 155 - Specifications for Shore Connection

Code of Federal Regulations, 2011 CFR

2011-07-01

... of this part] Item Description Dimension 1 Outside diameter 215 mm. (8 in.). 2 Inside diameter According to pipe outside diameter. 3 Bolt circle diameter 183 mm. (7 3/16 in.). 4 Slots in flange 6 holes 22 mm. (7/8 in.) in diameter shall be equidistantly placed on a bolt circle of the above diameter...

33 CFR Appendix A to Part 155 - Specifications for Shore Connection

Code of Federal Regulations, 2014 CFR

2014-07-01

... of this part] Item Description Dimension 1 Outside diameter 215 mm. (8 in.). 2 Inside diameter According to pipe outside diameter. 3 Bolt circle diameter 183 mm. (7 3/16 in.). 4 Slots in flange 6 holes 22 mm. (7/8 in.) in diameter shall be equidistantly placed on a bolt circle of the above diameter...

33 CFR Appendix A to Part 155 - Specifications for Shore Connection

Code of Federal Regulations, 2012 CFR

2012-07-01

... of this part] Item Description Dimension 1 Outside diameter 215 mm. (8 in.). 2 Inside diameter According to pipe outside diameter. 3 Bolt circle diameter 183 mm. (7 3/16 in.). 4 Slots in flange 6 holes 22 mm. (7/8 in.) in diameter shall be equidistantly placed on a bolt circle of the above diameter...

A loose bolt delays loading of Endeavour's external tank

NASA Technical Reports Server (NTRS)

2000-01-01

A closeup reveals the loose bracket, observed hanging down from the side of the White Room at Launch Pad 39B, that delayed loading of Endeavour's external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.

Entry Descent and Landing Workshop Proceedings. Volume 1; Inflatable Reentry Vehicle Experiment-3 (IRVE-3) Project Overview & Instrumentation

NASA Technical Reports Server (NTRS)

Dillman, Robert

2015-01-01

Entry mass at Mars is limited by the payload size that can be carried by a rigid capsule that can fit inside the launch vehicle fairing. Landing altitude at Mars is limited by ballistic coefficient (mass per area) of entry body. Inflatable technologies allow payload to use full diameter of launch fairing, and deploy larger aeroshell before atmospheric interface, landing more payload at a higher altitude. Also useful for return of large payloads from Low Earth Orbit (LEO).

An understanding of human dynamics in urban subway traffic from the Maximum Entropy Principle

NASA Astrophysics Data System (ADS)

Yong, Nuo; Ni, Shunjiang; Shen, Shifei; Ji, Xuewei

2016-08-01

We studied the distribution of entry time interval in Beijing subway traffic by analyzing the smart card transaction data, and then deduced the probability distribution function of entry time interval based on the Maximum Entropy Principle. Both theoretical derivation and data statistics indicated that the entry time interval obeys power-law distribution with an exponential cutoff. In addition, we pointed out the constraint conditions for the distribution form and discussed how the constraints affect the distribution function. It is speculated that for bursts and heavy tails in human dynamics, when the fitted power exponent is less than 1.0, it cannot be a pure power-law distribution, but with an exponential cutoff, which may be ignored in the previous studies.

Crack propagation of brittle rock under high geostress

NASA Astrophysics Data System (ADS)

Liu, Ning; Chu, Weijiang; Chen, Pingzhi

2018-03-01

Based on fracture mechanics and numerical methods, the characteristics and failure criterions of wall rock cracks including initiation, propagation, and coalescence are analyzed systematically under different conditions. In order to consider the interaction among cracks, adopt the sliding model of multi-cracks to simulate the splitting failure of rock in axial compress. The reinforcement of bolts and shotcrete supporting to rock mass can control the cracks propagation well. Adopt both theory analysis and simulation method to study the mechanism of controlling the propagation. The best fixed angle of bolts is calculated. Then use ansys to simulate the crack arrest function of bolt to crack. Analyze the influence of different factors on stress intensity factor. The method offer more scientific and rational criterion to evaluate the splitting failure of underground engineering under high geostress.

Structural aspects of cold-formed steel section designed as U-shape composite beam

NASA Astrophysics Data System (ADS)

Saggaff, Anis; Tahir, Mahmood Md.; Azimi, Mohammadamin; Alhajri, T. M.

2017-11-01

Composite beam construction usually associated with old-style Hot-Rolled Steel Section (HRSS) has proven to act much better in compare with Cold-Formed Steel Section (CFSS) sections due to thicker section. Due, it's getting popular to replace HRSS with CFSS in some aspects as a composite beam. The advantages such as lightweight, cost effective and easy to install have contributed to the apply CFSS as a preferred construction material for composite beam. There is a few technical data available regarding the application of the usage of CFSS as a composite system, despite the potentials use for residential and light-weight industrial constructions. This paper presents an experimental tests results which have been conducted using CFSS as composite beam. Composite action of CFSS arranged as double beam with Self-Compacting Concrete (SCC) slab are integrated together with bolted shear connectors were used. A full-scale test comprised of 3 proposed composite beam specimens with bolted shear connector spaced at 300 mm interval of grade 8.8 was using single nut with washer on flange of CFS, cast to the slab and loaded until failed. The test show that the bolted shear connector yielded better capacity of ultimate strength and ultimate moment for the proposed composite beam. It can be concluded that, bolted shear connectors of 16 mm in diameter performed better than the other diameter size of bolted shear connectors.

Optimised layout and roadway support planning with integrated intelligent software

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

Kouniali, S.; Josien, J.P.; Piguet, J.P.

1996-12-01

Experience with knowledge-based systems for Layout planning and roadway support dimensioning is on hand in European coal mining since 1985. The systems SOUT (Support choice and dimensioning, 1989), SOUT 2, PLANANK (planning of bolt-support), Exos (layout planning diagnosis. 1994), Sout 3 (1995) have been developed in close cooperation by CdF{sup 1}. INERIS{sup 2} , EMN{sup 3} (France) and RAG{sup 4}, DMT{sup 5}, TH - Aachen{sup 6} (Germany); ISLSP (Integrated Software for Layout and support planning) development is in progress (completion scheduled for July 1996). This new software technology in combination with conventional programming systems, numerical models and existing databases turnedmore » out to be suited for setting-up an intelligent decision aid for layout and roadway support planning. The system enhances reliability of planning and optimises the safety-to-cost ratio for (1) deformation forecast for roadways in seam and surrounding rocks, consideration of the general position of the roadway in the rock mass (zones of increased pressure, position of operating and mined panels); (2) support dimensioning; (3) yielding arches, rigid arches, porch sets, rigid rings, yielding rings and bolting/shotcreting for drifts; (4) yielding arches, rigid arches and porch sets for roadways in seam; and (5) bolt support for gateroads (assessment of exclusion criteria and calculation of the bolting pattern) bolting of face-end zones (feasibility and safety assessment; stability guarantee).« less

Probabilistic Simulation of Progressive Fracture in Bolted-Joint Composite Laminates

NASA Technical Reports Server (NTRS)

Minnetyan, L.; Singhal, S. N.; Chamis, C. C.

1996-01-01

This report describes computational methods to probabilistically simulate fracture in bolted composite structures. An innovative approach that is independent of stress intensity factors and fracture toughness was used to simulate progressive fracture. The effect of design variable uncertainties on structural damage was also quantified. A fast probability integrator assessed the scatter in the composite structure response before and after damage. Then the sensitivity of the response to design variables was computed. General-purpose methods, which are applicable to bolted joints in all types of structures and in all fracture processes-from damage initiation to unstable propagation and global structure collapse-were used. These methods were demonstrated for a bolted joint of a polymer matrix composite panel under edge loads. The effects of the fabrication process were included in the simulation of damage in the bolted panel. Results showed that the most effective way to reduce end displacement at fracture is to control both the load and the ply thickness. The cumulative probability for longitudinal stress in all plies was most sensitive to the load; in the 0 deg. plies it was very sensitive to ply thickness. The cumulative probability for transverse stress was most sensitive to the matrix coefficient of thermal expansion. In addition, fiber volume ratio and fiber transverse modulus both contributed significantly to the cumulative probability for the transverse stresses in all the plies.

Effects of musicality and motivational orientation on auditory category learning: a test of a regulatory-fit hypothesis.

PubMed

McAuley, J Devin; Henry, Molly J; Wedd, Alan; Pleskac, Timothy J; Cesario, Joseph

2012-02-01

Two experiments investigated the effects of musicality and motivational orientation on auditory category learning. In both experiments, participants learned to classify tone stimuli that varied in frequency and duration according to an initially unknown disjunctive rule; feedback involved gaining points for correct responses (a gains reward structure) or losing points for incorrect responses (a losses reward structure). For Experiment 1, participants were told at the start that musicians typically outperform nonmusicians on the task, and then they were asked to identify themselves as either a "musician" or a "nonmusician." For Experiment 2, participants were given either a promotion focus prime (a performance-based opportunity to gain entry into a raffle) or a prevention focus prime (a performance-based criterion that needed to be maintained to avoid losing an entry into a raffle) at the start of the experiment. Consistent with a regulatory-fit hypothesis, self-identified musicians and promotion-primed participants given a gains reward structure made more correct tone classifications and were more likely to discover the optimal disjunctive rule than were musicians and promotion-primed participants experiencing losses. Reward structure (gains vs. losses) had inconsistent effects on the performance of nonmusicians, and a weaker regulatory-fit effect was found for the prevention focus prime. Overall, the findings from this study demonstrate a regulatory-fit effect in the domain of auditory category learning and show that motivational orientation may contribute to musician performance advantages in auditory perception.

Reiter conducts a fit check of the Kazbek couches in the Soyuz TMA-8/12S

NASA Image and Video Library

2006-07-26

ISS013-E-60768 (26 July 2006) --- Attired in a Russian Sokol launch and entry suit, European Space Agency (ESA) astronaut Thomas Reiter, Expedition 13 flight engineer, participates in a Kazbek couch fit check in the TMA-8 Soyuz spacecraft docked to the International Space Station.

14. DETAIL OF CONNECTIONS AT THE BOTTOM OF A POST ...

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

14. DETAIL OF CONNECTIONS AT THE BOTTOM OF A POST IN THE WEST TRUSS, SHOWING THE ASSEMBLY OF LOWER CHORD AND DIAGONAL EYE BOLTS AND THE SUSPENSION OF A FLOOR BEAM FROM THE POST BY A U-BOLT; VIEW FROM SOUTH BANK. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

Rotation Capacity of Bolted Flush End-Plate Stiffened Beam-to-Column Connection

NASA Astrophysics Data System (ADS)

Ostrowski, Krzysztof; Kozłowski, Aleksander

2017-06-01

One of the flexibility parameters of semi-rigid joints is rotation capacity. Plastic rotation capacity is especially important in plastic design of framed structures. Current design codes, including Eurocode 3, do not posses procedures enabling designers to obtain value of rotation capacity. In the paper the calculation procedure of the rotation capacity for stiffened bolted flush end-plate beam-to-column connections has been proposed. Theory of experiment design was applied with the use of Hartley's PS/DS-P:Ha3 plan. The analysis was performed with the use of finite element method (ANSYS), based on the numerical experiment plan. The determination of maximal rotation angle was carried out with the use of regression analysis. The main variables analyzed in parametric study were: pitch of the bolt "w" (120-180 mm), the distance between the bolt axis and the beam upper edge cg1 (50-90 mm) and the thickness of the end-plate tp (10-20 mm). Power function was proposed to describe available rotation capacity of the joint. Influence of the particular components on the rotation capacity was also investigated. In the paper a general procedure for determination of rotation capacity was proposed.

Randomised controlled trial of the sliding hip screw versus X-Bolt Dynamic Hip Plating System for the fixation of trochanteric fractures of the hip in adults: a protocol study for WHiTE 4 (WHiTE4).

PubMed

Griffin, Xavier L; Achten, Juul; Sones, William; Cook, Jonathan; Costa, Matthew L

2018-01-26

Sliding hip screw fixation is well established in the treatment of trochanteric fractures of the hip. The X-Bolt Dynamic Hip Plating System builds on the successful design features of the sliding hip screw but differs in the nature of the fixation in the femoral head. A randomised pilot study suggested that the X-bolt Dynamic Hip Plating System might provide similar health-related quality of life while reducing the risk of revision surgery when compared with the sliding hip screw. This is the protocol for a multicentre randomised trial of sliding hip screw versus X-Bolt Dynamic Hip Plating System for patients 60 years and over treated for a trochanteric fracture of the hip. Multicentre, multisurgeon, parallel, two-arm, randomised controlled trial. Patients aged 60 years and older with a trochanteric hip fracture are potentially eligible. Participants will be randomly allocated on a 1:1 basis to either sliding hip screw or X-Bolt Dynamic Hip Plating System. Otherwise, all care will be in accordance with National Institute for Health and Care Excellence guidance. A minimum of 1128 patients will be recruited to obtain 90% power to detect a 0.075-point difference in EuroQol-5D health-related quality of life at 4 months postrandomisation. Secondary outcomes include mortality, residential status, revision surgery and radiographic measures. The treatment effect will be estimated using a two-sided t-test adjusted for age, gender and cognitive impairment based on an intention-to-treat analysis. National Research Ethics Committee approved this study on 5 February 2016 (16/WM/0001). The study is sponsored by the University of Oxford and funded through an investigator initiated grant by X-Bolt Orthopaedics. A manuscript for a high-impact peer-reviewed journal will be prepared, and the results will be disseminated to patients through local mechanisms at participating centres. ISRCTN92825709. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Silicon force sensor

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

Galambos, Paul C.; Crenshaw, Thomas B.; Nishida, Erik E.

The various technologies presented herein relate to a sensor for measurement of high forces and/or high load shock rate(s), whereby the sensor utilizes silicon as the sensing element. A plate of Si can have a thinned region formed therein on which can be formed a number of traces operating as a Wheatstone bridge. The brittle Si can be incorporated into a layered structure comprising ductile and/or compliant materials. The sensor can have a washer-like configuration which can be incorporated into a nut and bolt configuration, whereby tightening of the nut and bolt can facilitate application of a compressive preload uponmore » the sensor. Upon application of an impact load on the bolt, the compressive load on the sensor can be reduced (e.g., moves towards zero-load), however the magnitude of the preload can be such that the load on the sensor does not translate to tensile stress being applied to the sensor.« less

Three-dimensional nonsteady heat-transfer analysis of an indirect heating furnace

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

Ito, H.; Umeda, Y.; Nakamura, Y.

1991-01-01

This paper reports on an accurate design method for industrial furnaces from the viewpoint of heat transfer. The authors carried out a three-dimensional nonsteady heat-transfer analysis for a practical-size heat- treatment furnace equipped with radiant heaters. The authors applied three software package programs, STREAM, MORSE, and TRUMP, for the analysis of the combined heat-transfer problems of radiation, conduction, and convection. The authors also carried out experiments of the heating of a charge consisting of packed bolts. The authors found that the air swirled inside the furnace. As for the temperature in each part in the furnace, analytical results were generallymore » in close agreement with the experimental ones. This suggests that our analytical method is useful for a fundamental heat- transfer-based design of a practical-size industrial furnace with an actual charge such as packed bolts. As for the temperature distribution inside the bolt charge (work), the analytical results were also in close agreement with the experimental ones. Consequently, it was found that the heat transfer in the bolt charge could be described with an effective thermal conductivity.« less

Chief Joseph Dam, Columbia River, Washington, Additional Units and Structural Modification Foundation Report

DTIC Science & Technology

1988-01-01

diameter companion drain holes in the area below the intake structure. The second contract, DACW67-75-C-0042, was awarded to Goodfellow Brothers, Inc. in...tolerances for bolt anchors. Subhori- zontal companion drain holes were drilled adjacent to the rock bolt holes. Negligible ground water was encountered...excavation contract was then modified so that rock excavation would not go below elevation 799 feet. The contractor installed rock bolts and companion drain

A loose bolt delays loading of Endeavour's external tank

NASA Technical Reports Server (NTRS)

2000-01-01

This view shows the pipe (center top) leading toward Endeavour from the side of the White Room at Launch Pad 39B. A loose bracket observed hanging down from the pipe delayed loading of Endeavour's external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.

Shear Behaviour and Acoustic Emission Characteristics of Bolted Rock Joints with Different Roughnesses

NASA Astrophysics Data System (ADS)

Wang, Gang; Zhang, Yongzheng; Jiang, Yujing; Liu, Peixun; Guo, Yanshuang; Liu, Jiankang; Ma, Ming; Wang, Ke; Wang, Shugang

2018-06-01

To study shear failure, acoustic emission counts and characteristics of bolted jointed rock-like specimens are evaluated under compressive shear loading. Model joint surfaces with different roughnesses are made of rock-like material (i.e. cement). The jointed rock masses are anchored with bolts with different elongation rates. The characteristics of the shear mechanical properties, the failure mechanism, and the acoustic emission parameters of the anchored joints are studied under different surface roughnesses and anchorage conditions. The shear strength and residual strength increase with the roughness of the anchored joint surface. With an increase in bolt elongation, the shear strength of the anchored joint surface gradually decreases. When the anchored structural plane is sheared, the ideal cumulative impact curve can be divided into four stages: initial emission, critical instability, cumulative energy, and failure. With an increase in the roughness of the anchored joint surface, the peak energy rate and the cumulative number of events will also increase during macro-scale shear failure. With an increase in the bolt elongation, the energy rate and the event number increase during the shearing process. Furthermore, the peak energy rate, peak number of events and cumulative energy will all increase with the bolt elongation. The results of this study can provide guidance for the use of the acoustic emission technique in monitoring and predicting the static shear failure of anchored rock masses.

KSC-07pd2722

NASA Image and Video Library

2007-10-08

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Stephanie Wilson has her helmet adjusted during fitting of her launch and entry suit. The fitting is part of terminal countdown demonstration test, or TCDT, activities the crew is undertaking at NASA's Kennedy Space Center. The TCDT also includes emergency egress procedures, equipment familiarization and a simulated launch countdown. Mission STS-120, which will carry the Italian-built U.S. Node 2 to the International Space Station, is targeted for launch on Oct. 23. Photo credit: NASA/Kim Shiflett

KSC-07pd2720

NASA Image and Video Library

2007-10-08

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Daniel Tani has his helmet adjusted during fitting of his launch and entry suit. The fitting is part of terminal countdown demonstration test, or TCDT, activities the crew is undertaking at NASA's Kennedy Space Center. The TCDT also includes emergency egress procedures, equipment familiarization and a simulated launch countdown. Mission STS-120, which will carry the Italian-built U.S. Node 2 to the International Space Station, is targeted for launch on Oct. 23. Photo credit: NASA/Kim Shiflett

Pressure Dome for High-Pressure Electrolyzer

NASA Technical Reports Server (NTRS)

Norman, Timothy; Schmitt, Edwin

2012-01-01

A high-strength, low-weight pressure vessel dome was designed specifically to house a high-pressure [2,000 psi (approx. = 13.8 MPa)] electrolyzer. In operation, the dome is filled with an inert gas pressurized to roughly 100 psi (approx. = 690 kPa) above the high, balanced pressure product oxygen and hydrogen gas streams. The inert gas acts to reduce the clamping load on electrolyzer stack tie bolts since the dome pressure acting axially inward helps offset the outward axial forces from the stack gas pressure. Likewise, radial and circumferential stresses on electrolyzer frames are minimized. Because the dome is operated at a higher pressure than the electrolyzer product gas, any external electrolyzer leak prevents oxygen or hydrogen from leaking into the dome. Instead the affected stack gas stream pressure rises detectably, thereby enabling a system shutdown. All electrical and fluid connections to the stack are made inside the pressure dome and require special plumbing and electrical dome interfaces for this to be accomplished. Further benefits of the dome are that it can act as a containment shield in the unlikely event of a catastrophic failure. Studies indicate that, for a given active area (and hence, cell ID), frame outside diameter must become ever larger to support stresses at higher operating pressures. This can lead to a large footprint and increased costs associated with thicker and/or larger diameter end-plates, tie-rods, and the frames themselves. One solution is to employ rings that fit snugly around the frame. This complicates stack assembly and is sometimes difficult to achieve in practice, as its success is strongly dependent on frame and ring tolerances, gas pressure, and operating temperature. A pressure dome permits an otherwise low-pressure stack to operate at higher pressures without growing the electrolyzer hardware. The pressure dome consists of two machined segments. An O-ring is placed in an O-ring groove in the flange of the bottom segment and is trapped by the flange on the top dome segment when these components are bolted together with high-strength bolts. The pressure dome has several unique features. It is made (to ASME Pressure Vessel guidelines) in a high-strength aluminum alloy with the strength of stainless steel and the weight benefits of aluminum. The flange of the upper dome portion contains specially machined flats for mounting the dome, and other flats dedicated to the special feedthroughs for electrical connections. A pressure dome can be increased in length to house larger stacks (more cells) of the same diameter with the simple addition of a cylindrical segment. To aid in dome assembly, two stainless steel rings are employed. One is used beneath the heads of the high-strength bolts in lieu of individual hardened washers, and another is used instead of individual nuts. Like electrolyzers could be operated at low or high pressures simply by operating the electrolyzer outside or inside a pressurized dome.

A torque, tension and stress corrosion evaluation of high strength A286 bolts

NASA Technical Reports Server (NTRS)

Montano, J. W.

1986-01-01

The problems associated with overtorque applied to the Booster Separation Motor (BSM) Igniter Adapter high strength 200 KSI (1379 Mpa) A286 CRES bolts and the threaded holes of the 7075-T73 aluminum alloy BSM cases are addressed. The evaluation included torque, tensile, and stress corrosion tests incorporating the A286 CRES bolts and the 7075-T73 aluminum alloy BSM cases. The tensile test data includes ultimate tensile load (UTL), Johnson's 2/3 yield load (J2/3YL), proportional limit load (PLL), and total bolt stretch. Torque tension data includes torque, torque induced load, and positive and negative break-away torque. Stress corrosion test data reflect the overtorque and the resulting torque induced loads sustained by the A286 CRES bolts torqued into a 7075-T73 aluminum alloy forged dome with threaded holes. After 60 days of salt fog exposure, the positive and the negative break-away torques, the subsequent mechanical property tensile test results, and the BSM dome threaded hole axial tensile pullout loads are reported.

[Effects of temperature on leaf lettuce vernalization.

PubMed

Zhang, Li Li; Hao, Jing Hong; Han, Ying Yan; Liu, Chao Jie; Su, He Nan; Li, Pan Pan; Sun, Yan Chuan; Fan, Shuang Xi

2016-11-18

To investigate the effects of different temperatures on the vernalization of leaf lettuce, and declare their type, two easy bolting leaf lettuce varieties of GB-30 and GB-31 were selected as material, which were treated by 4 ℃, 20 ℃ and 25 ℃ for 20 d respectively and afterwards treated by high temperature stress. The process of flower bud differentiation was observed by using paraffin section technology, and combined the condition of bolting and flowering to estimate whether or not it underwent vernalization, and defined its vernalization type. The results showed that, two varieties of GB-30 and GB-31 appeared bolting to different degrees at the 8 th day under high temperature stress after temperature treatments in the early stage. Different temperatures in the early stage all made flower bud differentiated of two varieties. 4 ℃ treatment did not advance the flower bud differentiation, while the high temperature in later time accelerated this progress. Furthermore, the days required for the two varieties to complete development stages differed under different temperature treatments. The effective accumulated temperature whether from pregermination to flowering or from high temperature stress to flowering of two varieties were also different. The leaf lettuce without low temperature treatment in early stage could enter into the flower bud differentiation, bolting, budding and flowering stages, and it could be considered as non-low temperature vernalization plant. The high temperature treatment in later stage could obviously promote its bolting and flowering. In addition, the effective accumulated temperature had to reach about 2500 ℃·d from germination to blossom.

Data Recovery of Distributed Hash Table with Distributed-to-Distributed Data Copy

NASA Astrophysics Data System (ADS)

Doi, Yusuke; Wakayama, Shirou; Ozaki, Satoshi

To realize huge-scale information services, many Distributed Hash Table (DHT) based systems have been proposed. For example, there are some proposals to manage item-level product traceability information with DHTs. In such an application, each entry of a huge number of item-level IDs need to be available on a DHT. To ensure data availability, the soft-state approach has been employed in previous works. However, this does not scale well against the number of entries on a DHT. As we expect 1010 products in the traceability case, the soft-state approach is unacceptable. In this paper, we propose Distributed-to-Distributed Data Copy (D3C). With D3C, users can reconstruct the data as they detect data loss, or even migrate to another DHT system. We show why it scales well against the number of entries on a DHT. We have confirmed our approach with a prototype. Evaluation shows our approach fits well on a DHT with a low rate of failure and a huge number of data entries.

Demonstration of a Pyrotechnic Bolt-Retractor System

NASA Technical Reports Server (NTRS)

Johnston, Nick; Ahmed, Rafiq; Garrison, Craig; Gaines, Joseph; Waggoner, Jason

2004-01-01

A paper describes a demonstration of the X-38 bolt-retractor system (BRS) on a spacecraft-simulating apparatus, called the Large Mobility Base, in NASA's Flight Robotics Laboratory (FRL). The BRS design was proven safe by testing in NASA's Pyrotechnic Shock Facility (PSF) before being demonstrated in the FRL. The paper describes the BRS, FRL, PSF, and interface hardware. Information on the bolt-retraction time and spacecraft-simulator acceleration, and an analysis of forces, are presented. The purpose of the demonstration was to show the capability of the FRL for testing of the use of pyrotechnics to separate stages of a spacecraft. Although a formal test was not performed because of schedule and budget constraints, the data in the report show that the BRS is a successful design concept and the FRL is suitable for future separation tests.

Ultrasonic extensometer measures bolt preload

NASA Technical Reports Server (NTRS)

Daniels, C. M., Jr.

1978-01-01

Extensometer using ultrasonic pulse reflections to measure elongations in tightened belts and studs is much more accurate than conventional torque wrenches in application of specified preload to bolts and other threaded fasteners.

Fabricated torque shaft

DOEpatents

Mashey, Thomas Charles

2002-01-01

A fabricated torque shaft is provided that features a bolt-together design to allow vane schedule revisions with minimal hardware cost. The bolt-together design further facilitates on-site vane schedule revisions with parts that are comparatively small. The fabricated torque shaft also accommodates stage schedules that are different one from another in non-linear inter-relationships as well as non-linear schedules for a particular stage of vanes.

Effect of product form, compaction, vibration and comminution on energywood bulk density

Treesearch

Tim P. McDonald; Bryce J. Stokes; J.F. McNeel

1995-01-01

A study was performed to examine the changes in density of stacked roundwood, chips, and chunks as affected by various compaction treatments. Density of stacked roundwood bolts was tested for the effect of stacking orientation, binding of the stack ends, and species. Stacked bolt wood occupied less than 50 percent of the total rack space for all species, giving final...

Model based Inverse Methods for Sizing Cracks of Varying Shape and Location in Bolt hole Eddy Current (BHEC) Inspections (Postprint)

DTIC Science & Technology

2016-02-10

using bolt hole eddy current (BHEC) techniques. Data was acquired for a wide range of crack sizes and shapes, including mid- bore , corner and through...to select the most appropriate VIC-3D surrogate model for subsequent crack sizing inversion step. Inversion results for select mid- bore , through and...the flaw. 15. SUBJECT TERMS Bolt hole eddy current (BHEC); mid- bore , corner and through-thickness crack types; VIC-3D generated surrogate models

Small-Bolt Torque-Tension Tester

NASA Technical Reports Server (NTRS)

Posey, Alan J.

2009-01-01

The device described here measures the torque-tension relationship for fasteners as small as #0. The small-bolt tester consists of a plate of high-strength steel into which three miniature load cells are recessed. The depth of the recess is sized so that the three load cells can be shimmed, the optimum height depending upon the test hardware. The three miniature load cells are arranged in an equilateral triangular configuration with the test bolt aligned with the centroid of the three. This is a kinematic arrangement.

Targeted entry of enveloped viruses: measles and herpes simplex virus I.

PubMed

Navaratnarajah, Chanakha K; Miest, Tanner S; Carfi, Andrea; Cattaneo, Roberto

2012-02-01

We compare the receptor-based mechanisms that a small RNA virus and a larger DNA virus have evolved to drive the fusion of viral and cellular membranes. Both systems rely on tight control over triggering the concerted refolding of a trimeric fusion protein. While measles virus entry depends on a receptor-binding protein and a fusion protein only, the herpes simplex virus (HSV) is more complex and requires four viral proteins. Nevertheless, in both viruses a receptor-binding protein is required for triggering the membrane fusion process. Moreover, specificity domains can be appended to these receptor-binding proteins to target virus entry to cells expressing a designated receptor. We discuss how principles established with measles and HSV can be applied to targeting other enveloped viruses, and alternatively how retargeted envelopes can be fitted on foreign capsids. Copyright © 2011 Elsevier B.V. All rights reserved.

Use of two-dimensional transmission photoelastic models to study stresses in double-lap bolted joints

NASA Technical Reports Server (NTRS)

Hyer, M. W.; Liu, D. H.

1981-01-01

The stress distribution in two hole connectors in a double lap joint configuration was studied. The following steps are described: (1) fabrication of photoelastic models of double lap double hole joints designed to determine the stresses in the inner lap; (2) assessment of the effects of joint geometry on the stresses in the inner lap; and (3) quantification of differences in the stresses near the two holes. The two holes were on the centerline of the joint and the joints were loaded in tension, parallel to the centerline. Acrylic slip fit pins through the holes served as fasteners. Two dimensional transmission photoelastic models were fabricated by using transparent acrylic outer laps and a photoelastic model material for the inner laps. It is concluded that the photoelastic fringe patterns which are visible when the models are loaded are due almost entirely to stresses in the inner lap.

Investigation of the effects of extravehicular activity (EVA) gloves on performance

NASA Technical Reports Server (NTRS)

Bishu, Ram R.; Klute, Glenn

1993-01-01

The objective was to assess the effects of extravehicular activity (EVA) gloves at different pressures on human hand capabilities. A factorial experiment was performed in which three types of EVA gloves were tested at five pressure differentials. The independent variables tested in this experiment were gender, glove type, pressure differential, and glove make. Six subjects participated in an experiment where a number of dexterity measures, namely time to tie a rope, and the time to assemble a nut and bolt were recorded. Tactility was measured through a two point discrimination test. The results indicate that with EVA gloves strength is reduced by nearly 50 percent, there is a considerable reduction in dexterity, performance decrements increase with increasing pressure differential, and some interesting gender glove interactions were observed, some of which may have been due to the extent (or lack of) fit of the glove to the hand. The implications for the designer are discussed.

STS-52 backup Payload Specialist Tryggvason during JSC bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, backup Payload Specialist Bjarni V. Tryggvason, wearing launch and entry suit (LES), checks his launch and entry helmet (LEH) fitting prior to participating in emergency egress (bailout) training exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29. The WETF's 25-ft deep pool will serve as the ocean during this water landing simulation. Tryggvason represents the Canadian Space Agency (CSA).

Microstructure-Mechanical Property Relationships for a Fe/Mn/Cr Rock Bolt Reinforcing Steel

NASA Astrophysics Data System (ADS)

Panigrahi, B. K.

2010-08-01

The influence of low chromium additions to a 0.25C-1.5Mn semikilled steel on microstructure, and tensile and impact behaviors of high strength rock bolt reinforcing bars has been investigated. Although chromium imparted adequate tensile properties at ambient temperature (yield stress: 624 MPa; ultimate tensile stress: 819 MPa; elongation: 12.5%) by forming transformation products such as tempered martensite, lower and upper bainite, and small amounts of acicular ferrite, it increased the ductile-to-brittle transition temperature due to coarser upper bainite in the core region of bar having larger unit crack paths. The synthesized steel is considered to be effective in realizing the desired tensile properties, and suitable for application in rock bolt, as well as other reinforced concrete structures.

Two kissing bolts

NASA Astrophysics Data System (ADS)

Bossard, Guillaume; Katmadas, Stefanos; Turton, David

2018-02-01

The study of non-supersymmetric black hole microstates offers the potential to resolve the black hole information paradox. A system of equations was recently obtained that enables the systematic construction of non-supersymmetric smooth horizonless supergravity solutions, that are candidates to describe microstates of non-extremal black holes. Within this system we construct a family of six-dimensional supergravity solutions that feature two topologically-nontrivial three-cycles known as bolts. The two bolts touch at a single point and are supported by fluxes. We find that the fluxes on the two three-cycles can be either aligned or anti-aligned, and exhibit examples of both. We present several examples of smooth solutions, including near-extremal solutions that have an approximate AdS3 region, and far-from extremal solutions that have arbitrarily small charge compared to their mass.

15. CLOSEUP VIEW OF SOUTHEAST CABLE BOLT, SUSPENSION CABLE, AND ...

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

15. CLOSE-UP VIEW OF SOUTHEAST CABLE BOLT, SUSPENSION CABLE, AND CONCRETE ANCHORING BLOCK, LOOKING SOUTHEAST - San Rafael Bridge, Spanning San Rafael River near Buckhorn Wash, Castle Dale, Emery County, UT

Pressure-welded flange assembly provides leaktight seal at reduced bolt loads

NASA Technical Reports Server (NTRS)

Martenson, A. J.

1966-01-01

Vibration resistant flange-connector assembly provides a leaktight seal under reduced bolt loads. The assembly consists of ductile metal plates that are pressure welded between dies mounted in recessed flanges.

Failure analysis of single-bolted joint for lightweight composite laminates and metal plate

NASA Astrophysics Data System (ADS)

Li, Linjie; Qu, Junli; Liu, Xiangdong

2018-01-01

A three-dimensional progressive damage model was developed in ANSYS to predict the damage accumulation of single bolted joint in composite laminates under in-plane tensile loading. First, we describe the formulation and algorithm of this model. Second, we calculate the failure loads of the joint in fibre reinforced epoxy laminated composite plates and compare it with the experiment results, which validates that our model can appropriately simulate the ultimate tensile strength of the joints and the whole process of failure of structure. Finally, this model is applied to study the failure process of the light-weight composite material (USN125). The study also has a great potential to provide a strong basis for bolted joints design in composite Laminates as well as a simple tool for comparing different laminate geometries and bolt arrangements.

RxPATROL: a Web-based tool for combating pharmacy theft.

PubMed

Smith, Meredith Y; Graham, J Aaron; Haddox, J David; Steffey, Amy

2009-01-01

To report the incidence of pharmacy-related burglaries and robberies and characteristics of pharmacies where such crimes have occurred using recent data from Rx Pattern Analysis Tracking Robberies & Other Losses (RxPATROL), a national Web-based information clearinghouse on pharmacy-related theft of prescription medications and over-the-counter products. Descriptive, nonexperimental study. United States between 2005 and 2006. Not applicable. Not applicable. Number of pharmacy theft reports received; incident type, date, and location; point of entry; and pharmacy security features. Between 2005 and 2006, 202 pharmacy burglary and 299 pharmacy robbery reports from 45 different states were filed with RxPATROL. More than 70% of pharmacies reporting such crimes lacked a security camera. Among those reporting a burglary, 60% lacked dead bolt locks, a solid exterior door, a motion detector device, or a safe or vault for storage of controlled substances. Burglars most often obtained access to the pharmacy via the front door. RxPATROL is a Web-based tool that can assist pharmacies and law enforcement in collaborating more effectively to combat and prevent pharmacy-related crimes.

Rock bolt overload warning device

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

Unrug, K.F.

1983-10-18

A washer is described which is used in the construction of the support for the roof of a mine. The washer is fabricated such that finger like projections rupture in stages as the tension on bolts and pressure in the strata of the roof of the mine increases beyond structurely safe limits. The rupturing of the washer emits audible warning signals and also provides a visual indication of an unsafe condition.

Using Impact Modulation to Identify Loose Bolts on a Satellite

DTIC Science & Technology

2011-10-21

for public release; distribution is unlimited the literature to be an effective damage detection method for cracks, delamination, and fatigue in...to identify loose bolts and fatigue damage using optimized sensor locations using a Support Vector Machines algorithm to classify the dam- age. Finally...48] did preliminary work which showed that VM is effective in detecting fatigue cracks in engineering components despite changes in actuator location

Variables Affecting Probability of Detection in Bolt Hole Eddy Current Inspection

NASA Astrophysics Data System (ADS)

Lemire, H.; Krause, T. W.; Bunn, M.; Butcher, D. J.

2009-03-01

Physical variables affecting probability of detection (POD) in a bolt-hole eddy current inspection were examined. The POD study involved simulated bolt holes in 7075-T6 aluminum coupons representative of wing areas on CC-130 and CP-140 aircraft. The data were obtained from 24 inspectors who inspected 468 coupons, containing a subset of coupons with 45 electric discharge machined notches and 72 laboratory grown fatigue cracks located at the inner surface corner of the bi-layer structures. A comparison of physical features of cracks and notches in light of skin depth effects and probe geometry was used to identify length rather than depth as the significant variable producing signal variation. Probability of detection based on length produced similar results for the two discontinuity types, except at lengths less than 0.4 mm, where POD for cracks was found to be higher than that of notches.

Variations over time in the effects of age and sex on hospitalization rates before and after admission to a nursing home: A German cohort study.

PubMed

Hoffmann, Falk; Allers, Katharina

2017-08-01

We examined hospitalization rates for nursing home residents before and after their entry to the home, stratified by sex and age. A cohort study was conducted using data from a large health insurance fund on 127,227 residents aged 65 years and over newly admitted to a nursing home between January 1, 2010, and December 31, 2014. We assessed hospitalization rates and proportions being hospitalized in 6-month intervals one year before nursing home placement and up to 5 years thereafter. Multiple Poisson regression models were fitted to calculate relative risks (RR). Mean age was 84.0 years and 74.6% of the cohort were females. Hospitalization rates were 194.4 per 100 person-years (PY) in the 12 months before entry to the nursing home and 120.0 per 100 PY thereafter. Rates were highest immediately before entry in both sexes. The influence of age was most pronounced in the 12-7 months before entry (RR: 2.37 for 65-74 vs. 95+ years) and declined thereafter (1.29-1.38 up to month 24 after entry). In contrast, the influence of sex was greater after entry (RR: 1.13 for males vs. females in the 12-7 months before and 1.23-1.31 up to month 24 after entry). Hospitalization rates of nursing home residents are much higher in Germany than in other Western countries. We have provided some insight into the influence of age and sex on hospitalization rates, which varied over the period (time before and after entry to the nursing home) analyzed. We urgently recommend that future studies on the hospitalization of residents stratify their analyses by sex, age and period. Copyright © 2017 Elsevier B.V. All rights reserved.

3D finite element analysis of tightening process of bolt and nut connections with pitch difference

NASA Astrophysics Data System (ADS)

Liu, X.; Noda, N.-A.; Sano, Y.; Huang, Y. T.; Takase, Y.

2018-06-01

In a wide industrial field, the bolt-nut joint is unitized as an important machine element and anti-loosening performance is always required. In this paper, the effect of a slight pitch difference between a bolt and nut is studied. Firstly, by varying the pitch difference, the prevailing torque required for the nut rotation, before the nut touches the clamped body, is measured experimentally. Secondly, the tightening torque is determined as a function of the axial force of the bolt after the nut touches the clamped body. The results show that a large value of pitch difference may provide large prevailing torque that causes an anti-loosening effect although a very large pitch difference may deteriorate the bolt axial force under a certain tightening torque. Thirdly, a suitable pitch difference is determined taking into account the anti-loosening and clamping abilities. Furthermore, the chamfered corners at nut ends are considered, and it is found that the 3D finite element analysis with considering the chamfered nut threads has a good agreement with the experimental observation. Finally, the most desirable pitch difference required for improving anti-loosening is proposed.

46 CFR 154.514 - Piping: Electrical bonding.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and Process Piping Systems § 154.514 Piping: Electrical bonding. (a) Cargo tanks or piping that are... strap attached by welding or bolting. (2) Two or more bolts that give metal to metal contact between the...

Ultrasonic inspection of studs (bolts) using dynamic predictive deconvolution and wave shaping.

PubMed

Suh, D M; Kim, W W; Chung, J G

1999-01-01

Bolt degradation has become a major issue in the nuclear industry since the 1980's. If small cracks in stud bolts are not detected early enough, they grow rapidly and cause catastrophic disasters. Their detection, despite its importance, is known to be a very difficult problem due to the complicated structures of the stud bolts. This paper presents a method of detecting and sizing a small crack in the root between two adjacent crests in threads. The key idea is from the fact that the mode-converted Rayleigh wave travels slowly down the face of the crack and turns from the intersection of the crack and the root of thread to the transducer. Thus, when a crack exists, a small delayed pulse due to the Rayleigh wave is detected between large regularly spaced pulses from the thread. The delay time is the same as the propagation delay time of the slow Rayleigh wave and is proportional to the site of the crack. To efficiently detect the slow Rayleigh wave, three methods based on digital signal processing are proposed: wave shaping, dynamic predictive deconvolution, and dynamic predictive deconvolution combined with wave shaping.

Development of a Fatigue Crack Growth Coupon for Highly Plastic Stress Conditions

NASA Technical Reports Server (NTRS)

Allen, Phillip A.; Aggarwal, Pravin K.; Swanson, Gregory R.

2003-01-01

This paper presents an analytical approach used to develop a novel fatigue crack growth coupon for a highly plastic 3-D stress field condition. The flight hardware investigated in this paper is a large separation bolt that fractures using pyrotechnics at the appointed time during the flight sequence. The separation bolt has a deep notch that produces a severe stress concentration and a large plastic zone when highly loaded. For this geometry, linear-elastic fracture mechanics (LEFM) techniques are not valid due to the large nonlinear stress field. Unfortunately, industry codes that are generally available for fracture mechanics analysis and fatigue crack growth (e.g. NASGRO (11) are limited to LEFM and are available for only a limited number of geometries. The results of LEFM based codes are questionable when used on geometries with significant plasticity. Therefore elastic-plastic fracture mechanics (EPFM) techniques using the finite element method (FEM) were used to analyze the bolt and test coupons. scale flight hardware is very costly in t e r n of assets, laboratory resources, and schedule. Therefore to alleviate some of these problems, a series of novel test coupons were developed to simulate the elastic-plastic stress field present in the bolt.

Assessment and evaluation of noise controls on roof bolting equipment and a method for predicting sound pressure levels in underground coal mining

NASA Astrophysics Data System (ADS)

Matetic, Rudy J.

Over-exposure to noise remains a widespread and serious health hazard in the U.S. mining industries despite 25 years of regulation. Every day, 80% of the nation's miners go to work in an environment where the time weighted average (TWA) noise level exceeds 85 dBA and more than 25% of the miners are exposed to a TWA noise level that exceeds 90 dBA, the permissible exposure limit (PEL). Additionally, MSHA coal noise sample data collected from 2000 to 2002 show that 65% of the equipment whose operators exceeded 100% noise dosage comprise only seven different types of machines; auger miners, bulldozers, continuous miners, front end loaders, roof bolters, shuttle cars (electric), and trucks. In addition, the MSHA data indicate that the roof bolter is third among all the equipment and second among equipment in underground coal whose operators exceed 100% dosage. A research program was implemented to: (1) determine, characterize and to measure sound power levels radiated by a roof bolting machine during differing drilling configurations (thrust, rotational speed, penetration rate, etc.) and utilizing differing types of drilling methods in high compressive strength rock media (>20,000 psi). The research approach characterized the sound power level results from laboratory testing and provided the mining industry with empirical data relative to utilizing differing noise control technologies (drilling configurations and types of drilling methods) in reducing sound power level emissions on a roof bolting machine; (2) distinguish and correlate the empirical data into one, statistically valid, equation, in which, provided the mining industry with a tool to predict overall sound power levels of a roof bolting machine given any type of drilling configuration and drilling method utilized in industry; (3) provided the mining industry with several approaches to predict or determine sound pressure levels in an underground coal mine utilizing laboratory test results from a roof bolting machine and (4) described a method for determining an operators' noise dosage of a roof bolting machine utilizing predicted or determined sound pressure levels.

The mechanism of bolt loading

NASA Technical Reports Server (NTRS)

Lee, H. M.

1992-01-01

It is shown that the mechanism of bolt loading for preloaded fasteners can be effectively portrayed through simple spring models and some algebraic manipulations. Understanding schematically what is involved in such joints provides insight into the distribution of loads. The developed equations confirm that for both symmetric and nonsymmetric joints the loading plane factor and the stiffness factor directly affect the load seen in preloaded fasteners. The manner in which an external loading is transferred through the joint can be explained as energy dissipated in the various springs of both the abutment and the bolt itself.

Complication assessment and prevention strategies using midfoot fusion bolt for medial column stabilization in Charcot's osteoarthropathy.

PubMed

Mehlhorn, Alexander T; Walther, Markus; Iblher, Niklas; Südkamp, Norbert P; Schmal, Hagen

2016-12-01

In Charcot's osteoarthropathy stabilization of the medial column of the foot was introduced in order to establish a stable foot and reduce the risk for amputation. This study was performed to analyze postoperative complications, define risk factors for those and develop strategies for prevention. Since bolt dislocation takes place frequently, it was aimed to predict an appropriate time point for bolt removal under the condition that osseous healing has occurred. Fourteen consecutive patients with neuroosteoarthropathy of the foot and arch collapse were treated with open reduction and stabilization using midfoot fusion bolt and lateral lag screws. Age, gender, presence of preoperative osteomyelitis or ulcer, number of complications and operative revisions, Hba1c value, consolidation of arthrodesis, presence of a load-bearing foot and period to bolt dislocation was assessed. The mean follow-up was 21.4±14.6 (mean±SDM) months, 64% of patients suffered from diabetes with a preoperative Hba1c of 8.5±2.4. The mean number of revisions per foot was 3.6±4.1. Bolt dislocation was seen in 57% of the patients following 11.3±8.5 months; in 75% of these patients bony healing occurred before dislocation. There was a significant association between preoperative increased Hba1c value, presence of preoperative ulcer and wound infection. Healing of arthrodesis was demonstrated in 57% and a permanent weight-bearing foot without recurrent ulcer was achieved in 79%. The early and late postoperative complications could be controlled in general. A fully load-bearing and stable foot was obtained, despite osseous consolidation was not detected in all of these cases. Once a stable foot has established early removal of fusion bolt should be considered. To decrease the risk of infection Hba1c should be adjusted and ulcers should be treated before the operation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design and Verification of Space Station EVA-Operated Truss Attachment System

NASA Technical Reports Server (NTRS)

Katell, Gabriel

2001-01-01

This paper describes the design and verification of a system used to attach two segments of the International Space Station (ISS). This system was first used in space to mate the P6 and Z1 trusses together in December 2000, through a combination of robotic and extravehicular tasks. Features that provided capture, coarse alignment, and fine alignment during the berthing process are described. Attachment of this high value hardware was critical to the ISS's sequential assembly, necessitating the inclusion of backup design and operational features. Astronauts checked for the proper performance of the alignment and bolting features during on-orbit operations. During berthing, the system accommodates truss-to-truss relative displacements that are caused by manufacturing tolerances and on-orbit thermal gradients. After bolt installation, the truss interface becomes statically determinate with respect to in-plane shear loads and isolates attach bolts from bending moments. The approach used to estimate relative displacements and the means of accommodating them is explained. Confidence in system performance was achieved through a cost-effective collection of tests and analyses, including thermal, structural, vibration, misalignment, contact dynamics, underwater simulation, and full-scale functional testing. Design considerations that have potential application to other mechanisms include accommodating variations of friction coefficients in the on-orbit joints, wrench torque tolerances, joint preload, moving element clearances at temperature extremes, and bolt-nut torque reaction.

Electrical servo actuator bracket. [fuel control valves on jet engines

NASA Technical Reports Server (NTRS)

Sawyer, R. V. (Inventor)

1981-01-01

An electrical servo actuator is mounted on a support arm which is allowed to pivot on a bolt through a fixed mounting bracket. The actuator is pivotally connected to the end of the support arm by a bolt which has an extension allowed to pass through a slot in the fixed mounting bracket. An actuator rod extends from the servo actuator to a crank arm which turns a control shaft. A short linear thrust of the rod pivots the crank arm through about 90 for full-on control with the rod contracted into the servo actuator, and full-off control when the rod is extended from the actuator. A spring moves the servo actuator and actuator rod toward the control crank arm once the actuator rod is fully extended in the full-off position. This assures the turning of the control shaft to a full-off position. A stop bolt and slot are provided to limit pivot motion. Once fully extended, the spring pivots the motion.

Silicon force sensor and method of using the same

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

Galambos, Paul C.; Crenshaw, Thomas B.; Nishida, Erik E.

The various technologies presented herein relate to a sensor for measurement of high forces and/or high load shock rate(s), whereby the sensor utilizes silicon as the sensing element. A plate of Si can have a thinned region formed therein on which can be formed a number of traces operating as a Wheatstone bridge. The brittle Si can be incorporated into a layered structure comprising ductile and/or compliant materials. The sensor can have a washer-like configuration which can be incorporated into a nut and bolt configuration, whereby tightening of the nut and bolt can facilitate application of a compressive preload uponmore » the sensor. Upon application of an impact load on the bolt, the compressive load on the sensor can be reduced (e.g., moves towards zero-load), however the magnitude of the preload can be such that the load on the sensor does not translate to tensile stress being applied to the sensor.« less

KSC-2014-4197

NASA Image and Video Library

2014-08-19

CAPE CANAVERAL, Fla. – Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians prepare to do a fit check of the forward bay cover for the Orion crew module. The cover is a shell that fits over Orion's crew module to protect the spacecraft during launch, orbital flight and re-entry into Earth's atmosphere. When Orion returns from space, the cover must be jettisoned high above the ground so that the parachutes can deploy and unfurl. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch in December 2014 atop a United Launch Alliance Delta IV Heavy rocket and in 2018 on NASA’s Space Launch System rocket. For more information, visit http://www.nasa.gov/orion. Photo credit: NASA/Daniel Casper

KSC-2014-4198

NASA Image and Video Library

2014-08-19

CAPE CANAVERAL, Fla. – Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians prepare to do a fit check of the forward bay cover for the Orion crew module. The cover is a shell that fits over Orion's crew module to protect the spacecraft during launch, orbital flight and re-entry into Earth's atmosphere. When Orion returns from space, the cover must be jettisoned high above the ground so that the parachutes can deploy and unfurl. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch in December 2014 atop a United Launch Alliance Delta IV Heavy rocket and in 2018 on NASA’s Space Launch System rocket. For more information, visit http://www.nasa.gov/orion. Photo credit: NASA/Daniel Casper

KSC-2014-4199

NASA Image and Video Library

2014-08-19

CAPE CANAVERAL, Fla. – Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians prepare to do a fit check of the forward bay cover for the Orion crew module. The cover is a shell that fits over Orion's crew module to protect the spacecraft during launch, orbital flight and re-entry into Earth's atmosphere. When Orion returns from space, the cover must be jettisoned high above the ground so that the parachutes can deploy and unfurl. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch in December 2014 atop a United Launch Alliance Delta IV Heavy rocket and in 2018 on NASA’s Space Launch System rocket. For more information, visit http://www.nasa.gov/orion. Photo credit: NASA/Daniel Casper

Analytic Guidance for the First Entry in a Skip Atmospheric Entry

NASA Technical Reports Server (NTRS)

Garcia-Llama, Eduardo

2007-01-01

This paper presents an analytic method to generate a reference drag trajectory for the first entry portion of a skip atmospheric entry. The drag reference, expressed as a polynomial function of the velocity, will meet the conditions necessary to fit the requirements of the complete entry phase. The generic method proposed to generate the drag reference profile is further simplified by thinking of the drag and the velocity as density and cumulative distribution functions respectively. With this notion it will be shown that the reference drag profile can be obtained by solving a linear algebraic system of equations. The resulting drag profile is flown using the feedback linearization method of differential geometric control as guidance law with the error dynamics of a second order homogeneous equation in the form of a damped oscillator. This approach was first proposed as a revisited version of the Space Shuttle Orbiter entry guidance. However, this paper will show that it can be used to fly the first entry in a skip entry trajectory. In doing so, the gains in the error dynamics will be changed at a certain point along the trajectory to improve the tracking performance.

Arc Jet Testing of the TIRS Cover Thermal Protection System for Mars Exploration Rover

NASA Technical Reports Server (NTRS)

Szalai, Christine E.; Chen, Y.-K.; Loomis, Mark; Hui, Frank; Scrivens, Larry

2002-01-01

This paper summarizes the arc jet test results of the Mars Exploration Rover (MER) Silicone Impregnated Reusable Ceramic Ablator (SIRCA) Transverse Impulse Rocket System (TIRS) Cover test series in the Panel Test Facility (PTF) at NASA Ames Research Center (ARC). NASA ARC performed aerothermal environment analyses, TPS sizing and thermal response analyses, and arc jet testing to evaluate the MER SIRCA TIRS Cover design and interface to the aeroshell structure. The primary objective of this arc jet test series was to evaluate specific design details of the SIRCA TIRS Cover interface to the MER aeroshell under simulated atmospheric entry heating conditions. Four test articles were tested in an arc jet environment with various sea] configurations. The test condition was designed to match the predicted peak flight heat load at the gap region between the SIRCA and the backshell TPS material, SLA-561S, and resulted in an over-test (with respect to heat flux and heat load) for the apex region of the SIRCA TIRS Cover. The resulting pressure differential was as much as twenty times that predicted for the flight case, depending on the location, and there was no post-test visual evidence of over-heating or damage to the seal, bracket, or backshell structure. The exposed titanium bolts were in good condition at post-test and showed only a small amount of oxidation at the leading edge locations. Repeatable thermocouple data were obtained and SIRCA thermal response analyses were compared to applicable thermocouple data. For the apex region of the SIRCA TIRS Cover, a one-dimensional thermal response prediction proved overly conservative, as there were strong multi-dimensional conduction effects evident from the thermocouple data. The one-dimensional thermal response prediction compared well with the thermocouple data for the leading edge "lip" region at the bolt location. In general, the test results yield confidence in the baseline seal design to prevent hot gas ingestion at the bracket and composite aeroshell structure interface.

Easy insert, easy release toggle bolt fastener

NASA Technical Reports Server (NTRS)

Kubokawa, C. C.

1970-01-01

Releasable pin-type toggle bolt fastener is constructed so that, when positioned in hole, toggle action prevents its removal and locknut anchors it firmly in place. Fastener is easily removed by loosening locknut and retraction of toggle wings.

KSC-2010-4648

NASA Image and Video Library

2010-09-13

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a left-side main separation bolt attaches the bottom of space shuttle Discovery to its external fuel tank in the Vehicle Assembly Building. As technicians were attaching the bolt Sept. 10, a bolt nut slipped back into Discovery's aft compartment. To retrieve it, technicians entered Discovery’s aft section through an access door. They then moved the nut back into position to finish attaching the bolt, which is used to separate Discovery from the external tank once the shuttle is in orbit. Discovery is scheduled to roll out to Launch Pad 39A later this month for its STS-133 launch to the International Space Station. Targeted to lift off Nov. 1, Discovery will take the Permanent Multipurpose Module (PMM) packed with supplies and critical spare parts, as well as Robonaut 2 (R2) to the station. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-4647

NASA Image and Video Library

2010-09-13

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a Vehicle Assembly Building technician adjusts a left-side main separation bolt that attaches the bottom of space shuttle Discovery to its external fuel tank. As technicians were attaching the bolt Sept. 10, a bolt nut slipped back into Discovery's aft compartment. To retrieve it, technicians entered Discovery’s aft section through an access door. They then moved the nut back into position to finish attaching the bolt, which is used to separate Discovery from the external tank once the shuttle is in orbit. Discovery is scheduled to roll out to Launch Pad 39A later this month for its STS-133 launch to the International Space Station. Targeted to lift off Nov. 1, Discovery will take the Permanent Multipurpose Module (PMM) packed with supplies and critical spare parts, as well as Robonaut 2 (R2) to the station. Photo credit: NASA/Dimitri Gerondidakis

Asthma and eligibility for the Australian Defence Force.

PubMed

Bailey, Jodi; Williams, Felicity

2009-11-01

Entry to the Australian Defence Force (ADF) for candidates with asthma has recently changed. This article summarises the ADF entry standards for candidates with asthma. It also explains the role of general practitioners in the safe and smooth transition to the military training environment for patients with asthma. Candidates with mild asthma may be considered for entry to the ADF subject to certain criteria which includes normal spirometry and negative bronchial provocation testing. If a candidate with asthma is assessed as fit to enter the ADF, they will need to present to their GP before entry to ensure they are prepared. Assistance from the GP in providing the patient with appropriate Asthma Action Plans, prescriptions, and medications is required to ensure continuity of care during what is often a challenging transition to military life.

A Faster Fastener

NASA Technical Reports Server (NTRS)

2000-01-01

A licensing agreement between Marshall Space Flight Center and M&A Screw and Machineworks has brought the quick connect nut to the commerical market. Originally designed as part of a project seeking in-space assembly techniques, the quick connect nut is secured around a bolt merely by pushing it onto the bolt and giving it a single twist. Applications for the nuts include oil drilling platforms, mining industry, and other practices that rely on speedy assembly for success.

Diaphragm flange and method for lowering particle beam impedance at connected beam tubes of a particle accelerator

DOEpatents

Biallas, George Herman

2017-07-04

A diaphragm flange for connecting the tubes in a particle accelerator while minimizing beamline impedance. The diaphragm flange includes an outer flange and a thin diaphragm integral with the outer flange. Bolt holes in the outer flange provide a means for bolting the diaphragm flange to an adjacent flange or beam tube having a mating bolt-hole pattern. The diaphragm flange includes a first surface for connection to the tube of a particle accelerator beamline and a second surface for connection to a CF flange. The second surface includes a recessed surface therein and a knife-edge on the recessed surface. The diaphragm includes a thickness that enables flexing of the integral diaphragm during assembly of beamline components. The knife-edge enables compression of a soft metal gasket to provide a leak-tight seal.

The importance of education, understanding, and empirical research in social work: the nuts and bolts of the business.

PubMed

Long, Kimberly; Wodarski, John S

2010-05-01

Over the past three decades, existing literature has demanded, and continues to demand, accountability in the delivery of social services through empirically based research and implementation of established norms: this is, and of itself, the true basis of social work. It is through these norms and empirically established models and theories of treatment that a social worker can really do what he/she wants to do: help the client. This article will describe the nuts and bolts of social work; i.e. those theories, models, and the established norms of practice. It is the desire of the author's that all social workers be educated in the nuts and bolts (basics) and that education will be based on empirical evidence that supports behavioral change through intervention and modification.

FragFit: a web-application for interactive modeling of protein segments into cryo-EM density maps.

PubMed

Tiemann, Johanna K S; Rose, Alexander S; Ismer, Jochen; Darvish, Mitra D; Hilal, Tarek; Spahn, Christian M T; Hildebrand, Peter W

2018-05-21

Cryo-electron microscopy (cryo-EM) is a standard method to determine the three-dimensional structures of molecular complexes. However, easy to use tools for modeling of protein segments into cryo-EM maps are sparse. Here, we present the FragFit web-application, a web server for interactive modeling of segments of up to 35 amino acids length into cryo-EM density maps. The fragments are provided by a regularly updated database containing at the moment about 1 billion entries extracted from PDB structures and can be readily integrated into a protein structure. Fragments are selected based on geometric criteria, sequence similarity and fit into a given cryo-EM density map. Web-based molecular visualization with the NGL Viewer allows interactive selection of fragments. The FragFit web-application, accessible at http://proteinformatics.de/FragFit, is free and open to all users, without any login requirements.

Investigation of high-strength bolt-tightening verification techniques.

DOT National Transportation Integrated Search

2016-03-01

The current means and methods of verifying that high-strength bolts have been properly tightened are very laborious and time : consuming. In some cases, the techniques require special equipment and, in other cases, the verification itself may be some...

Evaluation of an Online Study Skills Course

ERIC Educational Resources Information Center

Pryjmachuk, Steven; Gill, Anita; Wood, Patricia; Olleveant, Nicola; Keeley, Philip

2012-01-01

This article describes the evaluation of an online study skills course unit designed, using evidence-based principles, to support undergraduate students. A mixed-methods approach was employed to establish the extent to which the unit was (a) fit for purpose and (b) effective. Data were obtained from an online survey (n = 63) conducted on entry to…

KSC-2014-4200

NASA Image and Video Library

2014-08-19

CAPE CANAVERAL, Fla. – Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians monitor the progress as a crane lifts the forward bay cover for a fit check on the Orion crew module. The cover is a shell that fits over Orion's crew module to protect the spacecraft during launch, orbital flight and re-entry into Earth's atmosphere. When Orion returns from space, the cover must be jettisoned high above the ground so that the parachutes can deploy and unfurl. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch in December 2014 atop a United Launch Alliance Delta IV Heavy rocket and in 2018 on NASA’s Space Launch System rocket. For more information, visit http://www.nasa.gov/orion. Photo credit: NASA/Daniel Casper

KSC-2014-4201

NASA Image and Video Library

2014-08-19

CAPE CANAVERAL, Fla. – Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians on a work platform monitor the progress as a crane lowers the forward bay cover onto the Orion crew module for a fit check. The cover is a shell that fits over Orion's crew module to protect the spacecraft during launch, orbital flight and re-entry into Earth's atmosphere. When Orion returns from space, the cover must be jettisoned high above the ground so that the parachutes can deploy and unfurl. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch in December 2014 atop a United Launch Alliance Delta IV Heavy rocket and in 2018 on NASA’s Space Launch System rocket. For more information, visit http://www.nasa.gov/orion. Photo credit: NASA/Daniel Casper

Nondestructive Inspection Protocol for Reinforced Concrete Barriers [Tech Brief

DOT National Transportation Integrated Search

2014-09-01

Reinforced concrete barriers are generally anchored to the deck of a bridge or retaining wall using reinforcing steel protruding from the main structure or by anchored bars or bolts added during retrofits. Corrosion of steel bars or bolts can weaken ...

49 CFR 213.351 - Rail joints.

Code of Federal Regulations, 2014 CFR

2014-10-01

... shall be replaced. (c) If a joint bar is cracked or broken between the middle two bolt holes it shall be... in this subpart. (f) No rail shall have a bolt hole which is torch cut or burned. (g) No joint bar...

49 CFR 213.351 - Rail joints.

Code of Federal Regulations, 2013 CFR

2013-10-01

... shall be replaced. (c) If a joint bar is cracked or broken between the middle two bolt holes it shall be... in this subpart. (f) No rail shall have a bolt hole which is torch cut or burned. (g) No joint bar...

Low-Thermal-Resistance Baseplate Mounting

NASA Technical Reports Server (NTRS)

Perreault, W. T.

1984-01-01

Low-thermal-resistance mounting achieved by preloading baseplate to slight convexity with screws threaded through beam. As mounting bolts around edge of base-place tightened, baseplate and cold plate contact first in center, with region of intimate contact spreading outward as bolts tightened.

Steel shear strength of anchors with stand-off base plates.

DOT National Transportation Integrated Search

2013-09-01

Sign and signal structures are often connected to concrete foundations through a stand-off annular base plate with a double-nut anchor bolt connection, which leaves exposed anchor bolt lengths below leveling nuts used in these connections. Cantilever...

An analysis of pipe flange connections using epoxy adhesives/anaerobic sealant instead of gaskets

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

Sawa, T.; Sasaki, R.; Yoneno, M.

1995-11-01

This paper deals with the strength and the sealing performance of pipe flange connections combining the bonding force of adhesives with the clamping force of bolts. The epoxy adhesives or anaerobic sealants are bonded at the interface partially instead of gaskets in pipe flange connections. The stress distribution in the epoxy adhesives (anaerobic sealant), which governs the sealing performance, and the variations in axial bolt force are analyzed, using an axisymmetrical theory of elasticity, when an internal pressure is applied to a connection in which two pipe flanges are clamped together buy bolts and nuts with an initial clamping forcemore » after being joined by epoxy adhesives or anaerobic sealant. In addition, a method for estimating the strength of the combination connection is demonstrated. Experiments are performed and the analytical results are consistent with the experimental results concerning the variation in axial bolt force and the strength of combination connections. It can be seen that the strength of connections increases with a decrease in the bolt pitch circle diameter. Furthermore, it is seen that the sealing performance of such combination connections in which the interface is bonded partially is improved over that of pipe flange connections with metallic gaskets.« less

Impact extractive fracture of jointed steel plates of a bolted joint

NASA Astrophysics Data System (ADS)

Daimaruya, M.; Fujiki, H.; Ambarita, H.

2012-08-01

This study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of a bolted joint used in a car body. For the accurate prediction of crash characteristics of car bodies by computer-aided engineering (CAE), it is also necessary to examine the behavior and fracture of jointed steel plates subjected to impact loads. Although the actual impact fracture of jointed steel plates of a bolted joint used in cars is complicated, for simplifying the problem it might be classified into the shear fracture and the extractive fracture of jointed steel plates. Attention is given to the extractive fracture of jointed steel plates in this study. The extractive behavior and fracture of three kinds of steel plates used for cars are examined in experiments and numerical simulations. The impact extraction test of steel plates jointed by a bolt is performed using the one-bar method, together with the static test. In order to understand the mechanism of extractive fracture process of jointed steel plates, numerical simulations by a FEM code LS-DYNA are also carried out. The obtained results suggest that a stress-based fracture criterion may be developed for the impact extractive fracture of jointed steel plates of a bolted joint used in a car body.

Mechanical Behavior of Dowel-Type Joints Made of Wood Scrimber Composite

PubMed Central

He, Minjuan; Tao, Duo; Li, Zheng; Li, Maolin

2016-01-01

As a renewable building material with low embodied energy characteristics, wood has gained more and more attention in the green and sustainable building industry. In terms of material resource and physical properties, scrimber composite not only makes full use of fast-growing wood species, but also has better mechanical performance and less inherent variability than natural wood material. In this study, the mechanical behavior of bolted beam-to-column joints built with a kind of scrimber composite was investigated both experimentally and numerically. Two groups of specimens were tested under monotonic and low frequency cyclic loading protocols. The experimental results showed that the bolted joints built with scrimber composite performed well in initial stiffness, ductility, and energy dissipation. A three-dimensional (3D) non-linear finite element model (FEM) for the bolted beam-to-column joints was then developed and validated by experimental results. The validated model was further used to investigate the failure mechanism of the bolted joints through stress analysis. This study can contribute to the application of the proposed scrimber composite in structural engineering, and the developed FEM can serve as a useful tool to evaluate the mechanical behavior of such bolted beam-to-column joints with different configurations in future research. PMID:28773703

Mechanical Behavior of Dowel-Type Joints Made of Wood Scrimber Composite.

PubMed

He, Minjuan; Tao, Duo; Li, Zheng; Li, Maolin

2016-07-15

As a renewable building material with low embodied energy characteristics, wood has gained more and more attention in the green and sustainable building industry. In terms of material resource and physical properties, scrimber composite not only makes full use of fast-growing wood species, but also has better mechanical performance and less inherent variability than natural wood material. In this study, the mechanical behavior of bolted beam-to-column joints built with a kind of scrimber composite was investigated both experimentally and numerically. Two groups of specimens were tested under monotonic and low frequency cyclic loading protocols. The experimental results showed that the bolted joints built with scrimber composite performed well in initial stiffness, ductility, and energy dissipation. A three-dimensional (3D) non-linear finite element model (FEM) for the bolted beam-to-column joints was then developed and validated by experimental results. The validated model was further used to investigate the failure mechanism of the bolted joints through stress analysis. This study can contribute to the application of the proposed scrimber composite in structural engineering, and the developed FEM can serve as a useful tool to evaluate the mechanical behavior of such bolted beam-to-column joints with different configurations in future research.

Nespoli during Kazbek Fit Check in the Soyuz TMA-20/25S

NASA Image and Video Library

2011-04-13

ISS027-E-013433 (13 April 2011) --- European Space Agency astronaut Paolo Nespoli, Expedition 27 flight engineer, attired in a Russian Sokol launch and entry suit, is pictured in the Soyuz TMA-20 spacecraft currently docked to the Rassvet Mini-Research Module 1 (MRM1) of the International Space Station. Nespoli was conducting a fit check of his Kazbek couch in the Soyuz.

Analysis of Bolted and Bonded Composite

DTIC Science & Technology

1992-09-01

pp. 1067-1079. 2-73. Askins, D. R. and D. R. Byrge, "Evaluation of 350°F Curing Adhesive Systems on Phosphoricn Acid Anodized Aluminum Substrates...Acceptable Aluminum Not compatible Cadmium Not compatible Chrom. plate Adequate with A286, PHI 3-8MO INCO 600 (Cobalt alloys) Good Low alloy steel Not... aluminum . Their tensile moduli are 30, 16 and 10 msi, respectively. The range for tensile strengths of steel and titanium bolts is approximately 220 to

An interview with Bruce A. Bolt

USGS Publications Warehouse

Spall, H.

1987-01-01

Professor Bruce Bolt was educated in Australia and first came to the United States in 1960 on a Fulbright Fellowship to the Lamont Geological Observatory of Columbia University. In 1963 he was appointed Director of the Seismographic Stations at the University of California at Berkeley. In June 1988, he steps down as Director but his association will continue as Professor of Seismology. Henry Spall interviewed him again 10 years after a 977 interview published in the Earthquake Information Bulletin. 

Effect of tree species and end seal on attractiveness and utility of cut bolts to the redbay Ambrosia beetle and granulate Ambrosia beetle (Coleoptera: Curculionidae: Scolytinae)

Treesearch

Albert E. Mayfield; James L. Hanula

2012-01-01

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a non-native invasive pest and vector of the fungus that causes laurel wilt disease in certain trees of the family Lauraceae. This study assessed the relative attractiveness and suitability of cut bolts of several tree species to X. glabratus. In 2009, female X. glabratus were equally attracted to traps...

Design of a Combined Ballistic Simulator and Primer Force Experimental Fixture

DTIC Science & Technology

2015-08-01

preload bolt and breech, and between the breech and chamber, were found to be too loose. When heavy grease or Teflon tape was used to tighten the...increase the difficulty of removing and tightening the breech. The preload bolt does not have to be removed between firing and in future designs could use... tightened it could loosen the primer plate, so left-handed threads were machined on the primer plate. The ballistic simulator fixture was occasionally

Quick action clamp

NASA Technical Reports Server (NTRS)

Calco, Frank S. (Inventor)

1991-01-01

A quick release toggle clamp that utilizes a spring that requires a deliberate positive action for disengagement is presented. The clamp has a sliding bolt that provides a latching mechanism. The bolt is moved by a handle that tends to remain in an engaged position while under tension.

Reinsertable Captive Bolt

NASA Technical Reports Server (NTRS)

Smallcombe, Richard D.

1994-01-01

Captive bolt installed, removed, and reinstalled easily, even with heavily gloved hands depriving technicians of feeling of engagement of threads. Has two threads with different diameters but same pitch. Engages either housing or mating part. Useful in construction in environments where visibility, tactility, and/or maneuverability poor.

Investigation of high-strength bolt-tightening verification techniques : tech transfer summary.

DOT National Transportation Integrated Search

2016-03-01

The primary objective of this project was to explore the current state-of-practice and the state-of-the-art techniques for high-strength bolt tightening and verification in structural steel connections. This project was completed so that insight coul...

KSC-2010-4645

NASA Image and Video Library

2010-09-13

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, space shuttle Discovery is attached to its external fuel tank and solid rocket boosters in the Vehicle Assembly Building. As technicians were attaching the left-side main separation bolt on the bottom of the shuttle to the external tank Sept. 10 a bolt nut slipped back into Discovery's aft compartment. To retrieve it, technicians entered Discovery’s aft section through an access door. They then moved the nut back into position to finish attaching the bolt, which is used to separate Discovery from the external tank once the shuttle is in orbit. Discovery is scheduled to roll out to Launch Pad 39A later this month for its STS-133 launch to the International Space Station. Targeted to lift off Nov. 1, Discovery will take the Permanent Multipurpose Module (PMM) packed with supplies and critical spare parts, as well as Robonaut 2 (R2) to the station. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-4644

NASA Image and Video Library

2010-09-13

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, technicians in the Vehicle Assembly Building inspect space shuttle Discovery, its external fuel tank and solid rocket boosters. As technicians were attaching the left-side main separation bolt on the bottom of the shuttle to the external tank Sept. 10 a bolt nut slipped back into Discovery's aft compartment. To retrieve it, technicians entered Discovery’s aft section through an access door. They then moved the nut back into position to finish attaching the bolt, which is used to separate Discovery from the external tank once the shuttle is in orbit. Discovery is scheduled to roll out to Launch Pad 39A later this month for its STS-133 launch to the International Space Station. Targeted to lift off Nov. 1, Discovery will take the Permanent Multipurpose Module (PMM) packed with supplies and critical spare parts, as well as Robonaut 2 (R2) to the station. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-4646

NASA Image and Video Library

2010-09-13

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, space shuttle Discovery is attached to its external fuel tank and solid rocket boosters in the Vehicle Assembly Building. As technicians were attaching the left-side main separation bolt on the bottom of the shuttle to the external tank Sept. 10 a bolt nut slipped back into Discovery's aft compartment. To retrieve it, technicians entered Discovery’s aft section through an access door. They then moved the nut back into position to finish attaching the bolt, which is used to separate Discovery from the external tank once the shuttle is in orbit. Discovery is scheduled to roll out to Launch Pad 39A later this month for its STS-133 launch to the International Space Station. Targeted to lift off Nov. 1, Discovery will take the Permanent Multipurpose Module (PMM) packed with supplies and critical spare parts, as well as Robonaut 2 (R2) to the station. Photo credit: NASA/Dimitri Gerondidakis

Engineers Attack the "No. One Killer" in Coal Mining: The Bureau of Mines and the Promotion of Roof Bolting, 1947-1969.

PubMed

Aldrich, Mark

In 1948 roof falls were the number one killer of coal miners in America. While the Bureau of Mines had been formed in 1910 to improve coalmine safety, it had largely focused on explosions, for which technological solutions appeared to exist. Roof falls, by contrast, were not amenable to a technical fix. Beginning in 1948, however, the Bureau discovered roof bolting, which it promoted as a safer technology that might yield dramatic benefits. The new approach spread rapidly, yet fatality rates from roof falls failed to decline for nearly two decades. This lag reflected the need for organizational learning, while companies also traded safety for productivity. Finally, only larger mines employed bolting and its impact was masked by a growth in the employment share of small companies. After 1965, as the expansion of small mines ended and organizational learning continued, fatality rates began a long decline.

Thermal Protection Materials: Development, Characterization and Evaluation

NASA Technical Reports Server (NTRS)

Johnson, Silvia M.

2012-01-01

Thermal protection materials and systems (TPS) are used to protect space vehicles from the heat experienced during entry into an atmosphere. The application for these materials is very specialized as are the materials. They must have specific properties to withstand conditions during specific entries. There is no one-size-fits-all TPS as the conditions experienced by a material are very dependent upon the atmosphere, the entry speed, the size and shape of the vehicle, and the location on the vehicle. However, all TPS must be reliable and efficient to ensure mission safety, that is to protect the vehicle while ensuring that payload is maximized. Types of TPS will be reviewed in relation to types of missions and applications. Both reusable and ablative materials will be discussed. Approaches to characterizing and evaluating these materials will be presented. The role of heritage versus new materials will be described.

Sensing the Tension

NASA Technical Reports Server (NTRS)

2003-01-01

Spanning over 4 decades, NASA's bolt tension monitoring technology has benefited automakers, airplane builders, and other major manufacturers that rely on the devices to evaluate the performance of computerized torque wrenches and other assembly line mechanisms. In recent years, the advancement of ultrasonic sensors has drastically eased this process for users, ensuring that proper tension and torque are being applied to bolts and fasteners, with less time needed for data analysis. Langley Research Center s Nondestructive Evaluation Branch is one of the latest NASA programs to incorporate ultrasonic sensors within a bolt tension measurement instrument. As a multi-disciplined research group focused on spacecraft and aerospace transportation safety, one of the branch s many commitments includes transferring problem solutions to industry. In 1998, the branch carried out this obligation in a licensing agreement with Micro Control, Inc., of West Bloomfield, Michigan. Micro Control, an automotive inspection company, obtained the licenses to two Langley patents to provide an improved-but-inexpensive means of ultrasonic tension measurement.

Noise trauma induced by a mousetrap--sound pressure level measurement of vole captive bolt devices.

PubMed

Frank, Matthias; Napp, Matthias; Lange, Joern; Grossjohann, Rico; Ekkernkamp, Axel; Beule, Achim G

2010-05-01

While ballistic parameters of vole captive bolt devices have been reported, there is no investigation on their hazardous potential to cause noise trauma. The aim of this experimental study was to measure the sound pressure levels of vole captive bolt devices. Two different shooting devices were examined with a modular precision sound level meter on an outdoor firing range. Measurements were taken in a semi-circular configuration with measuring points 0 degrees in front of the muzzle, 90 degrees at right angle of the muzzle, and 180 degrees behind the shooting device. Distances between muzzle and microphone were 0.5, 1, 2, 10, and 20 m. Sound pressure levels exceeded 130 dB(C) at any measuring point within the 20-m area. Highest measurements (more than 172 dB[C]) were taken in the 0 degrees direction at the 0.5-m distance for both shooting devices proving the hazardous potential of these gadgets to cause noise trauma.

Sealed Plant-Growth Chamber For Clinostat

NASA Technical Reports Server (NTRS)

Brown, Christopher S.; Dreschel, Thomas W.

1993-01-01

Laboratory chamber for growing plants used to measure photosynthesis and respiration in simulated microgravity. Holds plant specimens while rotated on clinostat, see article, "Clinostat Delivers Power To Plant-Growth Cabinets" (KSC-11537). Provides way of comparing gas-exchange rates of plants rotated horizontally on clinostat with those of stationary or vertically rotated plants. Gas extracted for analysis without stopping clinostat. Chamber includes potlike base and cylindrical cover, both made of transparent acrylic pipe. Gasket forms seal between cover and bottom plate of base. Cover bolted to pot baseplate, which in turn bolted to clinostat.

11. Corner of Derrick Showing Bolted Joints and DoublePipe/Wood Beam ...

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

11. Corner of Derrick Showing Bolted Joints and Double-Pipe/Wood Beam Support For Bull Wheel, Looking Southeast - David Renfrew Oil Rig, East side of Connoquenessing Creek, 0.4 mile North of confluence with Thorn Creek, Renfrew, Butler County, PA

Structural analysis of a bolted joint concept for the space shuttle's solid rocket motor casing

NASA Technical Reports Server (NTRS)

Lindell, Michael C.; Stalnaker, Winifred A.

1987-01-01

The Space Shuttle Challenger accident is thought to have been caused by the failure of one of the tang-clevis joints joining together the casing segments of the Solid Rocket Motors (SRM). Excessive displacement between the tang and clevis, possibly unseating the O-ring seals, may have initiated the resulting accident. An effort was made at NASA Langley Research Center to design an alternative concept for mating the casing segments. A bolted flange joint concept was designed and analyzed to determine if the concept would effectively maintain a seal while minimizing joint weight and controlling stress levels. It is shown that under the loading conditions analyzed the seal area of the joint remains seated. The only potential stress problem is a stress concentration in the flange at the edge of the bolt hole, which is highly localized. While heavier than the existing joint, this concept does have some advantages making the bolted joint an attractive alternative.

Bolt clampup relaxation in a graphite/epoxy laminate

NASA Technical Reports Server (NTRS)

Shivakumar, K. N.; Crews, J. H., Jr.

1982-01-01

A simple bolted joint was analyzed to calculate bolt clampup relaxation for a graphite/epoxy (T300/5208) laminate. A viscoelastic finite element analysis of a double-lap joint with a steel bolt was conducted. Clampup forces were calculated for various steady-state temperature-moisture conditions using a 20-year exposure duration. The finite element analysis predicted that clampup forces relax even for the room-temperature-dry condition. The relaxations were 8, 13, 20, and 30 percent for exposure durations of 1 day, 1 month, 1 year, and 20 years, respectively. As expected, higher temperatures and moisture levels each increased the relaxation rate. The combined viscoelastic effects of steady-state temperature and moisture appeared to be additive. From the finite-element analysis, a simple equation was developed for clampup force relaxation. This generalized equation was used to calculate clampup forces for the same temperature-moisture conditions as used in the finite-element analysis. The two sets of calculated results agreed well.

KSC-04PD-1316

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, Mike Bolt holds the Stanley Cup, won this year by the National Hockey Leagues Tampa Bay Lightning. Bolt is the Stanley Cup keeper. The cup was also briefly available for viewing by employees in the KSC Training Auditorium. Jay Feaster, general manager of the Tampa Bay Lightning, brought the cup to KSC while on a tour. The Stanley Cup weighs 35 pounds and is more than 100 years old. The Lightning will be added to the cup in September.

Structural health monitoring using a hybrid network of self-powered accelerometer and strain sensors

NASA Astrophysics Data System (ADS)

Alavi, Amir H.; Hasni, Hassene; Jiao, Pengcheng; Lajnef, Nizar

2017-04-01

This paper presents a structural damage identification approach based on the analysis of the data from a hybrid network of self-powered accelerometer and strain sensors. Numerical and experimental studies are conducted on a plate with bolted connections to verify the method. Piezoelectric ceramic Lead Zirconate Titanate (PZT)-5A ceramic discs and PZT-5H bimorph accelerometers are placed on the surface of the plate to measure the voltage changes due to damage progression. Damage is defined by loosening or removing one bolt at a time from the plate. The results show that the PZT accelerometers provide a fairly more consistent behavior than the PZT strain sensors. While some of the PZT strain sensors are not sensitive to the changes of the boundary condition, the bimorph accelerometers capture the mode changes from undamaged to missing bolt conditions. The results corresponding to the strain sensors are better indicator to the location of damage compared to the accelerometers. The characteristics of the overall structure can be monitored with even one accelerometer. On the other hand, several PZT strain sensors might be needed to localize the damage.

Standard Engineering Installation Package, Standard Remote Terminals (SRT).

DTIC Science & Technology

1981-10-30

6L L o 0 100 BOLT // M 0 (NOTE 3) N o @ 12 P o 13 NOTE: USE MiTN SAAD-D-4053 AND 0 14 • STD-SD-00SS DWS. 1I USE 3(4 CONDUIT AND BOX CONN. PUNCH OUT 3/4...TERMINAL STRIP. USE # BOLT TO MOUNT CONNECTOR TO DLII. USE OG STD-SO-007 FOR TERMINAL STRIP TERMINA- TION TO 153 PATCH PANEL. *1 f DUS1 is not or’dered... BOLTED TO FLOOR AS PER DUG 3I ®STu-SD-OO69 PROVIDING THERE IS INO CROSS OVLR WITH POWER AND SIGNAL CABLES. CROSSOVER WILL BE SEPERATED BY 4" MINIMUM

X-38 Bolt Retractor Subsystem Separation Demonstration

NASA Technical Reports Server (NTRS)

Rugless, Fedoria (Editor); Johnston, A. S.; Ahmed, R.; Garrison, J. C.; Gaines, J. L.; Waggoner, J. D.

2002-01-01

The Flight Robotics Laboratory FRL successfully demonstrated the X-38 bolt retractor subsystem (BRS). The BRS design was proven safe by testing in the Pyrotechnic Shock Facility (PSI) before being demonstrated in the FRL. This Technical Memorandum describes the BRS, FRL, PSF, and interface hardware. Bolt retraction time, spacecraft simulator acceleration, and a force analysis are also presented. The purpose of the demonstration was to show the FRL capability for spacecraft separation testing using pyrotechnics. Although a formal test was not performed due to schedule and budget constraints, the data will show that the BRS is a successful design concept and the FRL is suitable for future separation tests.

Video Intertank for the Core Stage for the first SLS Flight

NASA Image and Video Library

2017-06-29

This video shows the Space Launch System interank, which recently completed assembly at NASA's Michoud Assembly Facility in New Orleans. This tank was bolted together with more than 7,000 bolts. It is the only part of the SLS core stage assembly with bolts rather than by welding. The rocket's interank is located between the core stage liquid oxygen and liquid hydrogen fuel tanks. It has to be strong because the two SLS solid rocket boosters attache to the sides of it. This flight article will be connected to four other parts to form the core stage for the first integrated flight of SLS and Orion.

jsc2016e109765

NASA Image and Video Library

2016-09-09

At the Integration Facility at the Baikonur Cosmodrome in Kazakhstan, Expedition 49 crewmember Shane Kimbrough of NASA undergoes a pressure test on his Sokol launch and entry suit Sept. 9 during a pre-launch training fit check. Kimbrough and Sergey Ryzhikov and Andrey Borisenko of Roscosmos will launch Sept. 24, Kazakh time on the Soyuz MS-02 vehicle for a five-month mission on the International Space Station. NASA/Victor Zelentsov

Lubricating Holes for Corroded Nuts and Bolts

NASA Technical Reports Server (NTRS)

Penn, B. G.; Clemons, J. M.; Ledbetter, Frank E., III

1986-01-01

Corroded fasteners taken apart more easily. Lubricating holes bored to thread from three of flats. Holes facilitate application of penetrating oil to help loosen nut when rusted onto bolt. Holes make it possible to apply lubricants and rust removers directly to more of thread than otherwise reachable.

Tiedown Bracket

NASA Technical Reports Server (NTRS)

Mashburn, D.; Wald, J. E.; Helmsin, F. K.

1982-01-01

Tiedown bracket secured to concrete slab with lag anchor and lag bolt. A trailer or other heavy equipment can be anchored by tethering it to strapping bolt. When bracket is no longer needed, it can be removed, leaving behind only lag anchor. Bracket is easily installed and removed without damage to concrete slab.

Comparison of release torques of tightened bolts in vacuum and air

NASA Technical Reports Server (NTRS)

Demorest, K. E.

1970-01-01

Various combinations of stainless steel, mild steel, and aluminum bolt-nut couples are tightened to 60 lb-ft in partial vacuum and in air. Results are given for tests with and without two lubricants /a fluorosilicone and a sodium silicate bonded dry-film/.

12. TOOL ROOM SHOWING LANDIS MACHINE CO. BOL/T THREADER (L), ...

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

12. TOOL ROOM SHOWING LANDIS MACHINE CO. BOL/T THREADER (L), OSTER MANUFACTURING CO. PIPE MASTER (R), AND OLDMAN KINK, A SHOP-MADE WELDING STRENGTH TESTER (L, BACKGROUND). VIEW NORTHEAST - Oldman Boiler Works, Office/Machine Shop, 32 Illinois Street, Buffalo, Erie County, NY

76 FR 19719 - Airworthiness Directives; Saab AB, Saab Aerosystems Model SAAB 2000 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-08

... fretting corrosion; a detailed inspection of the actuator mounting bracket and shock struts for damage, cracks, and signs of corrosion; and doing corrective actions if necessary. Corrective actions include removing corrosion, replacing affected bolts with new bolts, tightening loose nuts, repairing, and...

3D-printed transparent facemasks in the treatment of facial hypertrophic scars of young children with burns.

PubMed

Wei, Yating; Li-Tsang, Cecilia W P; Liu, Jun; Xie, Lihua; Yue, Shukai

2017-05-01

Facial burns could create serious scar problems resulting disfigurement particularly on children. The conventional methods of producing transparent face masks for scar control remains complex and require dexterous skills of experienced clinician and patients' compliance during fitting. In this study, we adopted a portable 3D scanning and Computer-Aided Design (CAD) to produce 3D-printed transparent facemasks. Its efficacy was tested on two children with facial burns resulting hypertrophic scars. This study adopted a longitudinal case follow up research design. Two children with facial burns were recruited in the study upon consent. Their facial features were scanned with a portable 3D scanner and then edited and converted to the target files: the customized printable facemask files. The transparent facemask was directly printed out on the transparent biocompatible material followed by adding the medical grade silicone gel to provide extra pressure on the scar site. The facemasks were fitted to the patients with elastic straps connecting the printed anchoring bolts. Both children and family were instructed to wear the facemask for at least 20h per day and they were assessed before treatment, one month and three months after treatment on the facial scar conditions. At the one-month and three-month assessments after treatment, a decrease in average scar thickness was shown and the facial appearance was satisfactory. The 3D-printed facemasks were well fitted on both patients. The treatment was well-tolerated and no complication was reported. 3D-printed transparent facemask is convenient and efficient to fabricate, and is suitable for treating pediatric facial hypertrophic scars after burn. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Evaluation of insecticides for protecting Southwestern ponderosa pines from attack by engraver beetles (Coleoptera: Curculionidae: Scolytinae).

PubMed

DeGomez, Tom E; Hayes, Christopher J; Anhold, John A; McMillin, Joel D; Clancy, Karen M; Bosu, Paul P

2006-04-01

Insecticides that might protect pine trees from attack by engraver beetles (Ips spp.) have not been rigorously tested in the southwestern United States. We conducted two field experiments to evaluate the efficacy of several currently and potentially labeled preventative insecticides for protecting high-value ponderosa pine, Pinus ponderosa Dougl ex. Laws., from attack by engraver beetles. Preventative sprays (0.19% permethrin [Permethrin Plus C]; 0.03, 0.06, and 0.12% bifenthrin [Onyx]; and 1.0 and 2.0% carbaryl [Sevin SL] formulations) and systemic implants (0.875 g per capsule acephate [Acecap] and 0.650 g per capsule dinotefuran) were assessed on bolts (sections of logs) as a surrogate for live trees for a period of 13 mo posttreatment. The pine engraver, Ips pini (Say), was the most common bark beetle found attacking control and treated bolts, but sixspined ips, Ips calligraphus (Germar), and Ips lecontei Swain also were present. After approximately 13 mo posttreatment in one experiment, the spray treatments with 2.0% carbaryl, 0.19% permethrin, and 0.06 or 0.12% bifenthrin prevented Ips attack on the bolts at a protection level of > or = 70%. The acephate and dinotefuran systemic insecticides, and the 0.03% bifenthrin spray, provided inadequate (< or = 36%) protection in this experiment. For the other experiment, sprayed applications of 1.0% carbaryl, 0.19% permethrin, and 0.06% bifenthrin prevented beetle attack at protection levels of > or = 90, > or = 80, and > or = 70%, respectively, when bolts were exposed to Ips beetle attack for approximately 9-15 wk posttreatment. The sprays with 0.19% permethrin and 0.06% bifenthrin also provided > or = 90% protection when bolts were exposed for approximately 15-54 wk posttreatment. We concluded that under the conditions tested, 1.0 and 2.0% carbaryl, 0.19% permethrin, and 0.06 and 0.12% binfenthrin were acceptable preventative treatments for protecting ponderosa pine from successful engraver beetle attack for one entire flight season in the U.S. Southwest.

Nuts and Bolts - Techniques for Genesis Sample Curation

NASA Technical Reports Server (NTRS)

Burkett, Patti J.; Rodriquez, M. C.; Allton, J. H.

2011-01-01

The Genesis curation staff at NASA Johnson Space Center provides samples and data for analysis to the scientific community, following allocation approval by the Genesis Oversight Committee, a sub-committee of CAPTEM (Curation Analysis Planning Team for Extraterrestrial Materials). We are often asked by investigators within the scientific community how we choose samples to best fit the requirements of the request. Here we will demonstrate our techniques for characterizing samples and satisfying allocation requests. Even with a systematic approach, every allocation is unique. We are also providing updated status of the cataloging and characterization of solar wind collectors as of January 2011. The collection consists of 3721 inventoried samples consisting of a single fragment, or multiple fragments containerized or pressed between post-it notes, jars or vials of various sizes.