ORION Project-(SPLASH) Structural Passive Landing Attenuation fo

NASA Image and Video Library

2011-12-13

ORION Project-(SPLASH) Structural Passive Landing Attenuation for Survivability of Human Crew (BTA) Boiler Plate Test Article Water Impact Test-Pit Phase 4 Test or Pit 4 Tested at the Hydro Impact Basin at the Landing and Impact Research Facility (Gantry)

46 CFR 54.05-20 - Impact test properties for service of 0 °F and below.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Impact test properties for service of 0 °F and below. 54.05-20 Section 54.05-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Toughness Tests § 54.05-20 Impact test properties for service of 0 °F and below. (a) Test energy. The impact energies of...

Gun Testing Ballistics Issues for Insensitive Munitions Fragment Impact Testing

NASA Astrophysics Data System (ADS)

Baker, Ernest; Schultz, Emmanuel; NATO Munitions Safety Information Analysis Centre Team

2017-06-01

The STANAG 4496 Ed. 1 Fragment Impact, Munitions Test Procedure is normally conducted by gun launching a projectile for attack against a munition. The purpose of this test is to assess the reaction of a munition impacted by a fragment. The test specifies a standardized projectile (fragment) with a standard test velocity of 2530+/-90 m/s, or an alternate test velocity of 1830+/-60 m/s. The standard test velocity can be challenging to achieve and has several loosely defined and undefined characteristics that can affect the test item response. This publication documents the results of an international review of the STANAG 4496 related to the fragment impact test. To perform the review, MSIAC created a questionnaire in conjunction with the custodian of this STANAG and sent it to test centers. Fragment velocity variation, projectile tilt upon impact and aim point variation were identified as observed gun testing issues. Achieving 2530 m/s consistently and cost effectively can be challenging. The aim point of impact of the fragment is chosen with the objective of obtaining the most violent reaction. No tolerance for aim point is specified, although aim point variation can be a source for IM response variation. Fragment tilt on impact is also unspecified. The standard fragment fabricated from a variety of different steels which have a significant margin for mechanical properties. These, as well as other gun testing issues, have significant implications to resulting IM response.

Impact sensitivity of materials in contact with liquid and gaseous oxygen at high pressure

NASA Technical Reports Server (NTRS)

Schwinghamer, R. J.

1972-01-01

As a result of the Apollo 13 incident, increased emphasis is being placed on materials compatibility in a high pressure GOX environment. It is known that in addition to impact sensitivity of materials, approximately adiabatic compression conditions can contrive to induce materials reactivity. Test runs at high pressure using the ABMA tester indicate the following: (1) The materials used in the tests showed an inverse relationship between thickness and impact sensitivity. (2) Several materials tested exhibited greater impact sensitivity in GOX than in LOX. (3) The impact sensitivity of the materials tested in GOX, at the pressures tested, showed enhanced impact sensitivity with higher pressure. (4) The rank ordering of the materials tested in LOX up to 1000 psia is the same as the rank ordering resulting from tests in LOX at 14.7 psia.

Impact Testing for Materials Science at NASA - MSFC

NASA Technical Reports Server (NTRS)

Sikapizye, Mitch

2010-01-01

The Impact Testing Facility (ITF) at NASA - Marshall Space Flight Center is host to different types of guns used to study the effects of high velocity impacts. The testing facility has been and continues to be utilized for all NASA missions where impact testing is essential. The Facility has also performed tests for the Department of Defense, other corporations, as well as universities across the nation. Current capabilities provided by Marshall include ballistic guns, light gas guns, exploding wire gun, and the Hydrometeor Impact Gun. A new plasma gun has also been developed which would be able to propel particles at velocities of 20km/s. This report includes some of the guns used for impact testing at NASA Marshall and their capabilities.

Estimating the Impacts of Educational Interventions Using State Tests or Study-Administered Tests. NCEE 2012-4016

ERIC Educational Resources Information Center

Olsen, Robert B.; Unlu, Fatih; Price, Cristofer; Jaciw, Andrew P.

2011-01-01

This report examines the differences in impact estimates and standard errors that arise when these are derived using state achievement tests only (as pre-tests and post-tests), study-administered tests only, or some combination of state- and study-administered tests. State tests may yield different evaluation results relative to a test that is…

Notched bar Izod impact properties of zinc die castings

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

Schrems, K.K.; Dogan, O.N.; Goodwin, F.E.

2007-03-01

Notched bar Izod impact testing of zinc die cast Alloy 3, Alloy 5, ZA-8, and AcuZinc 5 was performed at five temperatures between -40\\mDC and room temperature in accordance with ASTM E23 for impact testing of metallic materials. A direct comparison between ASTM D256 for impact testing of plastics and ASTM E23 was performed using continuously cast zinc specimens of Alloy 5 and ZA-8 at -40\\mDC and room temperature. There are differences in sample sizes, impact velocity, and striker geometry between the two tests. Bulk zinc tested according to ASTM E23 resulted in higher impact energies at -40\\mDC and lowermore » impact energies at room temperature then did the same alloys when tested according to ASTM D256.« less

Rail Impact Testing. Test Operations Procedure (TOP)

DTIC Science & Technology

2008-09-15

impact test. The rail impact test is used to verify structural integrity of the test item and the adequacy of the tie-down system and tie-down...strength of provisions, connection and supporting structural frame, paragraph 5.2.3 ** Superscript...parts, to include outriggers and booms) without advanced approval by SDDCTEA. Torque nuts on wire rope clips to their correct value. Torque cable

Reinforced Carbon-Carbon Subcomponent Flat Plate Impact Testing for Space Shuttle Orbiter Return to Flight

NASA Technical Reports Server (NTRS)

Melis, Matthew E.; Brand, Jeremy H.; Pereira, J. Michael; Revilock, Duane M.

2007-01-01

Following the tragedy of the Space Shuttle Columbia on February 1, 2003, a major effort commenced to develop a better understanding of debris impacts and their effect on the Space Shuttle subsystems. An initiative to develop and validate physics-based computer models to predict damage from such impacts was a fundamental component of this effort. To develop the models it was necessary to physically characterize Reinforced Carbon-Carbon (RCC) and various debris materials which could potentially shed on ascent and impact the Orbiter RCC leading edges. The validated models enabled the launch system community to use the impact analysis software LS DYNA to predict damage by potential and actual impact events on the Orbiter leading edge and nose cap thermal protection systems. Validation of the material models was done through a three-level approach: fundamental tests to obtain independent static and dynamic material model properties of materials of interest, sub-component impact tests to provide highly controlled impact test data for the correlation and validation of the models, and full-scale impact tests to establish the final level of confidence for the analysis methodology. This paper discusses the second level subcomponent test program in detail and its application to the LS DYNA model validation process. The level two testing consisted of over one hundred impact tests in the NASA Glenn Research Center Ballistic Impact Lab on 6 by 6 in. and 6 by 12 in. flat plates of RCC and evaluated three types of debris projectiles: BX 265 External Tank foam, ice, and PDL 1034 External Tank foam. These impact tests helped determine the level of damage generated in the RCC flat plates by each projectile. The information obtained from this testing validated the LS DYNA damage prediction models and provided a certain level of confidence to begin performing analysis for full-size RCC test articles for returning NASA to flight with STS 114 and beyond.

Impact Testing on Reinforced Carbon-Carbon Flat Panels with Ice Projectiles for the Space Shuttle Return to Flight Program

NASA Technical Reports Server (NTRS)

Melis, Matthew E.; Revilock, Duane M.; Pereira, Michael J.; Lyle, Karen H.

2009-01-01

Following the tragedy of the Orbiter Columbia (STS-107) on February 1, 2003, a major effort commenced to develop a better understanding of debris impacts and their effect on the space shuttle subsystems. An initiative to develop and validate physics-based computer models to predict damage from such impacts was a fundamental component of this effort. To develop the models it was necessary to physically characterize reinforced carbon-carbon (RCC) along with ice and foam debris materials, which could shed on ascent and impact the orbiter RCC leading edges. The validated models enabled the launch system community to use the impact analysis software LS-DYNA (Livermore Software Technology Corp.) to predict damage by potential and actual impact events on the orbiter leading edge and nose cap thermal protection systems. Validation of the material models was done through a three-level approach: Level 1--fundamental tests to obtain independent static and dynamic constitutive model properties of materials of interest, Level 2--subcomponent impact tests to provide highly controlled impact test data for the correlation and validation of the models, and Level 3--full-scale orbiter leading-edge impact tests to establish the final level of confidence for the analysis methodology. This report discusses the Level 2 test program conducted in the NASA Glenn Research Center (GRC) Ballistic Impact Laboratory with ice projectile impact tests on flat RCC panels, and presents the data observed. The Level 2 testing consisted of 54 impact tests in the NASA GRC Ballistic Impact Laboratory on 6- by 6-in. and 6- by 12-in. flat plates of RCC and evaluated three types of debris projectiles: Single-crystal, polycrystal, and "soft" ice. These impact tests helped determine the level of damage generated in the RCC flat plates by each projectile and validated the use of the ice and RCC models for use in LS-DYNA.

Impact Testing on Reinforced Carbon-Carbon Flat Panels With BX-265 and PDL-1034 External Tank Foam for the Space Shuttle Return to Flight Program

NASA Technical Reports Server (NTRS)

Melis, Matthew E.; Revilock, Duane M.; Pereira, Michael J.; Lyle, Karen H.

2009-01-01

Following the tragedy of the Orbiter Columbia (STS-107) on February 1, 2003, a major effort commenced to develop a better understanding of debris impacts and their effect on the space shuttle subsystems. An initiative to develop and validate physics-based computer models to predict damage from such impacts was a fundamental component of this effort. To develop the models it was necessary to physically characterize reinforced carbon-carbon (RCC) along with ice and foam debris materials, which could shed on ascent and impact the orbiter RCC leading edges. The validated models enabled the launch system community to use the impact analysis software LS-DYNA (Livermore Software Technology Corp.) to predict damage by potential and actual impact events on the orbiter leading edge and nose cap thermal protection systems. Validation of the material models was done through a three-level approach: Level 1-fundamental tests to obtain independent static and dynamic constitutive model properties of materials of interest, Level 2-subcomponent impact tests to provide highly controlled impact test data for the correlation and validation of the models, and Level 3-full-scale orbiter leading-edge impact tests to establish the final level of confidence for the analysis methodology. This report discusses the Level 2 test program conducted in the NASA Glenn Research Center (GRC) Ballistic Impact Laboratory with external tank foam impact tests on flat RCC panels, and presents the data observed. The Level 2 testing consisted of 54 impact tests in the NASA GRC Ballistic Impact Laboratory on 6- by 6-in. and 6- by 12-in. flat plates of RCC and evaluated two types of debris projectiles: BX-265 and PDL-1034 external tank foam. These impact tests helped determine the level of damage generated in the RCC flat plates by each projectile and validated the use of the foam and RCC models for use in LS-DYNA.

76 FR 31860 - Anthropomorphic Test Devices; Hybrid III Test Dummy, ES-2re Side Impact Crash Test Dummy

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-02

... [Docket No. NHTSA-2010-0146] RIN 2127-AK64 Anthropomorphic Test Devices; Hybrid III Test Dummy, ES-2re Side Impact Crash Test Dummy AGENCY: National Highway Traffic Safety Administration (NHTSA), Department..., 2008, concerning a 50th percentile adult male side crash test dummy called the ``ES-2re'' test dummy...

Advanced Crew Escape Suits (ACES): Particle Impact Test

NASA Technical Reports Server (NTRS)

Rosales, Keisa R.; Stoltzfus, Joel M.

2009-01-01

NASA Johnson Space Center (JSC) requested NASA JSC White Sands Test Facility to assist in determining the effects of impaired anodization on aluminum parts in advanced crew escape suits (ACES). Initial investigation indicated poor anodization could lead to an increased risk of particle impact ignition, and a lack of data was prevalent for particle impact of bare (unanodized) aluminum; therefore, particle impact tests were performed. A total of 179 subsonic and 60 supersonic tests were performed with no ignition of the aluminum targets. Based on the resulting test data, WSTF found no increased particle impact hazard was present in the ACES equipment.

Drop-Weight Impact Test on U-Shape Concrete Specimens with Statistical and Regression Analyses

PubMed Central

Zhu, Xue-Chao; Zhu, Han; Li, Hao-Ran

2015-01-01

According to the principle and method of drop-weight impact test, the impact resistance of concrete was measured using self-designed U-shape specimens and a newly designed drop-weight impact test apparatus. A series of drop-weight impact tests were carried out with four different masses of drop hammers (0.875, 0.8, 0.675 and 0.5 kg). The test results show that the impact resistance results fail to follow a normal distribution. As expected, U-shaped specimens can predetermine the location of the cracks very well. It is also easy to record the cracks propagation during the test. The maximum of coefficient of variation in this study is 31.2%; it is lower than the values obtained from the American Concrete Institute (ACI) impact tests in the literature. By regression analysis, the linear relationship between the first-crack and ultimate failure impact resistance is good. It can suggested that a minimum number of specimens is required to reliably measure the properties of the material based on the observed levels of variation. PMID:28793540

49 CFR 572.191 - General description.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES IIsD Side Impact Crash Test Dummy, Small Adult Female § 572.191 General description. (a) The SID-IIsD Side Impact Crash Test Dummy... the SID-IIsD Side Impact Crash Test Dummy, 5th percentile adult female, is shown in drawing 180-0000...

49 CFR 572.181 - General description.

Code of Federal Regulations, 2012 CFR

2012-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 2re Side Impact Crash Test Dummy, 50th Percentile Adult Male § 572.181 General description. (a) The ES-2re Side Impact Crash Test... (PADI) of the ES-2re Side Impact Crash Test Dummy, February 2008, incorporated by reference, see § 572...

49 CFR 572.191 - General description.

Code of Federal Regulations, 2012 CFR

2012-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES IIsD Side Impact Crash Test Dummy, Small Adult Female § 572.191 General description. (a) The SID-IIsD Side Impact Crash Test Dummy... the SID-IIsD Side Impact Crash Test Dummy, 5th percentile adult female, is shown in drawing 180-0000...

Impact of the Community-Wide Adolescent Health Project on Sexually Transmitted Infection Testing in Omaha, Nebraska.

PubMed

Tibbits, Melissa; Maloney, Shannon; Ndashe, Tambudzai Phiri; Grimm, Brandon; Johansson, Patrik; Siahpush, Mohammad

2018-06-01

We describe the impact of the Adolescent Health Project on sexually transmitted infection (STI) testing in Omaha, NE, during phase 1 (media campaigns) and phase 2 (free STI testing). To assess the impact of each phase on STI testing, we examined monthly data from January 2013 to April 2017 via interrupted time series analyses. There was an immediate and statistically significant increase in testing during phase 2. Expanding and advertising free STI testing is a promising approach to increasing testing.

Pedestrian headform testing: inferring performance at impact speeds and for headform masses not tested, and estimating average performance in a range of real-world conditions.

PubMed

Hutchinson, T Paul; Anderson, Robert W G; Searson, Daniel J

2012-01-01

Tests are routinely conducted where instrumented headforms are projected at the fronts of cars to assess pedestrian safety. Better information would be obtained by accounting for performance over the range of expected impact conditions in the field. Moreover, methods will be required to integrate the assessment of secondary safety performance with primary safety systems that reduce the speeds of impacts. Thus, we discuss how to estimate performance over a range of impact conditions from performance in one test and how this information can be combined with information on the probability of different impact speeds to provide a balanced assessment of pedestrian safety. Theoretical consideration is given to 2 distinct aspects to impact safety performance: the test impact severity (measured by the head injury criterion, HIC) at a speed at which a structure does not bottom out and the speed at which bottoming out occurs. Further considerations are given to an injury risk function, the distribution of impact speeds likely in the field, and the effect of primary safety systems on impact speeds. These are used to calculate curves that estimate injuriousness for combinations of test HIC, bottoming out speed, and alternative distributions of impact speeds. The injuriousness of a structure that may be struck by the head of a pedestrian depends not only on the result of the impact test but also the bottoming out speed and the distribution of impact speeds. Example calculations indicate that the relationship between the test HIC and injuriousness extends over a larger range than is presently used by the European New Car Assessment Programme (Euro NCAP), that bottoming out at speeds only slightly higher than the test speed can significantly increase the injuriousness of an impact location and that effective primary safety systems that reduce impact speeds significantly modify the relationship between the test HIC and injuriousness. Present testing regimes do not take fully into account the relationship between impact severity and variations in impact conditions. Instead, they assess injury risk at a single impact speed. Hence, they may fail to differentiate risks due to the effects of bottoming out under different impact conditions. Because the level of injuriousness changes across a wide range of HIC values, even slight improvements to very stiff structures need to be encouraged through testing. Indications are that the potential of autonomous braking systems is substantial and needs to be weighted highly in vehicle safety assessments.

75 FR 5931 - Anthropomorphic Test Devices; Hybrid III Test Dummy, ES-2re Side Impact Crash Test Dummy

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-05

... [Docket No. NHTSA-2009-0194] RIN 2127-AK64 Anthropomorphic Test Devices; Hybrid III Test Dummy, ES-2re Side Impact Crash Test Dummy AGENCY: National Highway Traffic Safety Administration (NHTSA), Department... adopted specifications and qualification requirements for a new crash test dummy called the ``ES- 2re...

Multi-Terrain Vertical Drop Tests of a Composite Fuselage Section

NASA Technical Reports Server (NTRS)

Kellas, Sotiris; Jackson, Karen E.

2008-01-01

A 5-ft-diameter composite fuselage section was retrofitted with four identical blocks of deployable honeycomb energy absorber and crash tested on two different surfaces: soft soil, and water. The drop tests were conducted at the 70-ft. drop tower at the Landing and Impact Research (LandIR) Facility of NASA Langley. Water drop tests were performed into a 15-ft-diameter pool of water that was approximately 42-in. deep. For the soft soil impact, a 15-ft-square container filled with fine-sifted, unpacked sand was located beneath the drop tower. All drop tests were vertical with a nominally flat attitude with respect to the impact surface. The measured impact velocities were 37.4, and 24.7-fps for soft soil and water, respectively. A fuselage section without energy absorbers was also drop tested onto water to provide a datum for comparison with the test, which included energy absorbers. In order to facilitate this type of comparison and to ensure fuselage survivability for the no-energy-absorber case, the velocity of the water impact tests was restricted to 25-fps nominal. While all tests described in this paper were limited to vertical impact velocities, the implications and design challenges of utilizing external energy absorbers during combined forward and vertical impact velocities are discussed. The design, testing and selection of a honeycomb cover, which was required in soft surface and water impacts to transmit the load into the honeycomb cell walls, is also presented.

Capabilities of the Impact Testing Facility at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Finchum, Andy; Nehls, Mary; Young, Whitney; Gray, Perry; Suggs, Bart; Lowrey, Nikki M.

2011-01-01

The test and analysis capabilities of the Impact Testing Facility at NASA's Marshall Space Flight Center are described. Nine different gun systems accommodate a wide range of projectile and target sizes and shapes at velocities from subsonic through hypersonic, to accomplish a broad range of ballistic and hypervelocity impact tests. These gun systems include ballistic and microballistic gas and powder guns, a two-stage light gas gun, and specialty guns for weather encounter studies. The ITF "rain gun" is the only hydrometeor impact gun known to be in existence in the United States that can provide single impact performance data with known raindrop sizes. Simulation of high velocity impact is available using the Smooth Particle Hydrodynamic Code. The Impact Testing Facility provides testing, custom test configuration design and fabrication, and analytical services for NASA, the Department of Defense, academic institutions, international space agencies, and private industry in a secure facility located at Marshall Space Flight Center, on the US Army's Redstone Arsenal in Huntsville, Alabama. This facility performs tests that are subject to International Traffic in Arms Regulations (ITAR) and DoD secret classified restrictions as well as proprietary and unrestricted tests for civil space agencies, academic institutions, and commercial aerospace and defense companies and their suppliers.

Human-Robot Collaboration Dynamic Impact Testing and Calibration Instrument for Disposable Robot Safety Artifacts

PubMed Central

Dagalakis, Nicholas G.; Yoo, Jae Myung; Oeste, Thomas

2017-01-01

The Dynamic Impact Testing and Calibration Instrument (DITCI) is a simple instrument with a significant data collection and analysis capability that is used for the testing and calibration of biosimulant human tissue artifacts. These artifacts may be used to measure the severity of injuries caused in the case of a robot impact with a human. In this paper we describe the DITCI adjustable impact and flexible foundation mechanism, which allows the selection of a variety of impact force levels and foundation stiffness. The instrument can accommodate arrays of a variety of sensors and impact tools, simulating both real manufacturing tools and the testing requirements of standards setting organizations. A computer data acquisition system may collect a variety of impact motion, force, and torque data, which are used to develop a variety of mathematical model representations of the artifacts. Finally, we describe the fabrication and testing of human abdomen soft tissue artifacts, used to display the magnitude of impact tissue deformation. Impact tests were performed at various maximum impact force and average pressure levels. PMID:28579658

Human-Robot Collaboration Dynamic Impact Testing and Calibration Instrument for Disposable Robot Safety Artifacts.

PubMed

Dagalakis, Nicholas G; Yoo, Jae Myung; Oeste, Thomas

2016-01-01

The Dynamic Impact Testing and Calibration Instrument (DITCI) is a simple instrument with a significant data collection and analysis capability that is used for the testing and calibration of biosimulant human tissue artifacts. These artifacts may be used to measure the severity of injuries caused in the case of a robot impact with a human. In this paper we describe the DITCI adjustable impact and flexible foundation mechanism, which allows the selection of a variety of impact force levels and foundation stiffness. The instrument can accommodate arrays of a variety of sensors and impact tools, simulating both real manufacturing tools and the testing requirements of standards setting organizations. A computer data acquisition system may collect a variety of impact motion, force, and torque data, which are used to develop a variety of mathematical model representations of the artifacts. Finally, we describe the fabrication and testing of human abdomen soft tissue artifacts, used to display the magnitude of impact tissue deformation. Impact tests were performed at various maximum impact force and average pressure levels.

Understanding protocol performance: impact of test performance.

PubMed

Turner, Robert G

2013-01-01

This is the second of two articles that examine the factors that determine protocol performance. The objective of these articles is to provide a general understanding of protocol performance that can be used to estimate performance, establish limits on performance, decide if a protocol is justified, and ultimately select a protocol. The first article was concerned with protocol criterion and test correlation. It demonstrated the advantages and disadvantages of different criterion when all tests had the same performance. It also examined the impact of increasing test correlation on protocol performance and the characteristics of the different criteria. To examine the impact on protocol performance when individual tests in a protocol have different performance. This is evaluated for different criteria and test correlations. The results of the two articles are combined and summarized. A mathematical model is used to calculate protocol performance for different protocol criteria and test correlations when there are small to large variations in the performance of individual tests in the protocol. The performance of the individual tests that make up a protocol has a significant impact on the performance of the protocol. As expected, the better the performance of the individual tests, the better the performance of the protocol. Many of the characteristics of the different criteria are relatively independent of the variation in the performance of the individual tests. However, increasing test variation degrades some criteria advantages and causes a new disadvantage to appear. This negative impact increases as test variation increases and as more tests are added to the protocol. Best protocol performance is obtained when individual tests are uncorrelated and have the same performance. In general, the greater the variation in the performance of tests in the protocol, the more detrimental this variation is to protocol performance. Since this negative impact is increased as more tests are added to the protocol, greater test variation indicates using fewer tests in the protocol. American Academy of Audiology.

Organizational Benchmarks for Test Utilization Performance: An Example Based on Positivity Rates for Genetic Tests.

PubMed

Rudolf, Joseph; Jackson, Brian R; Wilson, Andrew R; Smock, Kristi J; Schmidt, Robert L

2017-04-01

Health care organizations are under increasing pressure to deliver value by improving test utilization management. Many factors, including organizational factors, could affect utilization performance. Past research has focused on the impact of specific interventions in single organizations. The impact of organizational factors is unknown. The objective of this study is to determine whether testing patterns are subject to organizational effects, ie, are utilization patterns for individual tests correlated within organizations. Comparative analysis of ordering patterns (positivity rates for three genetic tests) across 659 organizations. Hierarchical regression was used to assess the impact of organizational factors after controlling for test-level factors (mutation prevalence) and hospital bed size. Test positivity rates were correlated within organizations. Organizations have a statistically significant impact on the positivity rate of three genetic tests. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Personal Narratives of Genetic Testing: Expectations, Emotions, and Impact on Self and Family.

PubMed

Anderson, Emily E; Wasson, Katherine

2015-01-01

The stories in this volume shed light on the potential of narrative inquiry to fill gaps in knowledge, particularly given the mixed results of quantitative research on patient views of and experiences with genetic and genomic testing. Published studies investigate predictors of testing (particularly risk perceptions and worry); psychological and behavioral responses to testing; and potential impact on the health care system (e.g., when patients bring DTC genetic test results to their primary care provider). Interestingly, these themes did not dominate the narratives published in this issue. Rather, these narratives included consistent themes of expectations and looking for answers; complex emotions; areas of contradiction and conflict; and family impact. More narrative research on patient experiences with genetic testing may fill gaps in knowledge regarding how patients define the benefits of testing, changes in psychological and emotional reactions to test results over time, and the impact of testing on families.

49 CFR 572.18 - Thorax.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 11. (b) When impacted by a test probe conforming to § 572.21(a) at 13 fps in accordance with... parallel to the face of the test probe. (4) Place the longitudinal centerline of the test probe to coincide with the designated impact point and align the test probe so that at impact its longitudinal centerline...

49 CFR 572.18 - Thorax.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 11. (b) When impacted by a test probe conforming to § 572.21(a) at 13 fps in accordance with... parallel to the face of the test probe. (4) Place the longitudinal centerline of the test probe to coincide with the designated impact point and align the test probe so that at impact its longitudinal centerline...

49 CFR 572.18 - Thorax.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 11. (b) When impacted by a test probe conforming to § 572.21(a) at 13 fps in accordance with... parallel to the face of the test probe. (4) Place the longitudinal centerline of the test probe to coincide with the designated impact point and align the test probe so that at impact its longitudinal centerline...

49 CFR 572.18 - Thorax.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 11. (b) When impacted by a test probe conforming to § 572.21(a) at 13 fps in accordance with... parallel to the face of the test probe. (4) Place the longitudinal centerline of the test probe to coincide with the designated impact point and align the test probe so that at impact its longitudinal centerline...

Examining the Effects of Stereotype Threat on Test-Taking Behaviors

ERIC Educational Resources Information Center

Scherbaum, Charles A.; Blanshetyn, Victoria; Marshall-Wolp, Elizabeth; McCue, Elizabeth; Strauss, Ross

2011-01-01

This study examines the relationship between stereotype threat and individual test-taking behaviors. Previous research has examined the impact of stereotype threat on test scores, but little research has examined the impact of stereotype threat on the test-taking behaviors impacting those scores. Using a pre-post experimental design, stereotype…

Elemental Water Impact Test: Phase 1 20-Inch Hemisphere

NASA Technical Reports Server (NTRS)

Vassilakos, Gregory J.

2015-01-01

Spacecraft are being designed based on LS-DYNA simulations of water landing impacts. The Elemental Water Impact Test (EWIT) series was undertaken to assess the accuracy of LS-DYNA water impact simulations. Phase 1 of the EWIT series featured water impact tests of a 20-inch hemisphere dropped from heights of 5 feet and 10 feet. The hemisphere was outfitted with an accelerometer and three pressure gages. The focus of this report is the correlation of analytical models against test data.

Impact Testing of the H1224A Shipping/Storage Container

DTIC Science & Technology

1994-05-01

may not provide significant ener- gy absorption for the re - entry vehicle midsection but can provide some confinement of potentially damaged...Horizontal Low-Velocity impact test LHV Longitudinal High-Velocity impact test HHV Horizontal High-Velocity impact test RV Re - entry Vehicle midsection mass...Also, integration of these pulses showed that only a much shorter dura- tion pulse was necessary to slow the re - entry vehicle midsection velocity

A Comparison of Quasi-Static Indentation to Low-Velocity Impact

NASA Technical Reports Server (NTRS)

Nettles, A. T.; Douglas, M. J.

2000-01-01

A static test method for modeling low-velocity foreign object impact events to composites would prove to be very beneficial to researchers since much more data can be obtained from a static test than from an impact test. In order to examine if this is feasible, a series of static indentation and low-velocity impact tests were carried out and compared. Square specimens of many sizes and thicknesses were utilized to cover the array of types of low velocity impact events. Laminates with a pi/4 stacking sequence were employed since this is by far the most common type of engineering laminate. Three distinct flexural rigidities -under two different boundary conditions were tested in order to obtain damage ranging from that due to large deflection to contact stresses and levels in-between to examine if the static indentation-impact comparisons are valid under the spectrum of damage modes that can be experienced. Comparisons between static indentation and low-velocity impact tests were based on the maximum applied transverse load. The dependent parameters examined included dent depth, back surface crack length, delamination area, and to a limited extent, load-deflection behavior. Results showed that no distinct differences could be seen between the static indentation tests and the low-velocity impact tests, indicating that static indentation can be used to represent a low-velocity impact event.

78 FR 59659 - Correction to the Final Environmental Impact Statement/Overseas Environmental Impact Statement...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-27

... Statement/Overseas Environmental Impact Statement for Hawaii-Southern California Training and Testing AGENCY... Final Environmental Impact Statement (EIS)/Overseas EIS (OEIS) for Hawaii- Southern California Training.... Navy Training and Testing Activities in the Hawaii- Southern California Training and Testing Study Area...

Impact Testing of Aluminum 2024 and Titanium 6Al-4V for Material Model Development

NASA Technical Reports Server (NTRS)

Pereira, J. Michael; Revilock, Duane M.; Lerch, Bradley A.; Ruggeri, Charles R.

2013-01-01

One of the difficulties with developing and verifying accurate impact models is that parameters such as high strain rate material properties, failure modes, static properties, and impact test measurements are often obtained from a variety of different sources using different materials, with little control over consistency among the different sources. In addition there is often a lack of quantitative measurements in impact tests to which the models can be compared. To alleviate some of these problems, a project is underway to develop a consistent set of material property, impact test data and failure analysis for a variety of aircraft materials that can be used to develop improved impact failure and deformation models. This project is jointly funded by the NASA Glenn Research Center and the FAA William J. Hughes Technical Center. Unique features of this set of data are that all material property data and impact test data are obtained using identical material, the test methods and procedures are extensively documented and all of the raw data is available. Four parallel efforts are currently underway: Measurement of material deformation and failure response over a wide range of strain rates and temperatures and failure analysis of material property specimens and impact test articles conducted by The Ohio State University; development of improved numerical modeling techniques for deformation and failure conducted by The George Washington University; impact testing of flat panels and substructures conducted by NASA Glenn Research Center. This report describes impact testing which has been done on aluminum (Al) 2024 and titanium (Ti) 6Al-4vanadium (V) sheet and plate samples of different thicknesses and with different types of projectiles, one a regular cylinder and one with a more complex geometry incorporating features representative of a jet engine fan blade. Data from this testing will be used in validating material models developed under this program. The material tests and the material models developed in this program will be published in separate reports.

Modified Drop Tower Impact Tests for American Football Helmets.

PubMed

Rush, G Alston; Prabhu, R; Rush, Gus A; Williams, Lakiesha N; Horstemeyer, M F

2017-02-19

A modified National Operating Committee on Standards for Athletic Equipment (NOCSAE) test method for American football helmet drop impact test standards is presented that would provide better assessment of a helmet's on-field impact performance by including a faceguard on the helmet. In this study, a merger of faceguard and helmet test standards is proposed. The need for a more robust systematic approach to football helmet testing procedures is emphasized by comparing representative results of the Head Injury Criterion (HIC), Severity Index (SI), and peak acceleration values for different helmets at different helmet locations under modified NOCSAE standard drop tower tests. Essentially, these comparative drop test results revealed that the faceguard adds a stiffening kinematic constraint to the shell that lessens total energy absorption. The current NOCSAE standard test methods can be improved to represent on-field helmet hits by attaching the faceguards to helmets and by including two new helmet impact locations (Front Top and Front Top Boss). The reported football helmet test method gives a more accurate representation of a helmet's performance and its ability to mitigate on-field impacts while promoting safer football helmets.

Full scale tank car coupler impact tests

DOT National Transportation Integrated Search

2003-11-15

Full scale tests were performed to investigate various : aspects of tank car behavior during coupler impacts. A tank car : was equipped with 37 accelerometers and an instrumented : coupler. Two series of full scale coupler impact tests, : comprising ...

Hypervelocity Impact Testing of IM7/977-3 with Micro-Sized Particles

NASA Technical Reports Server (NTRS)

Smith, J. G.; Jegley, D. C.; Siochi, E. J.; Wells, B. K.

2010-01-01

Ground-based hypervelocity imapct testing was conducted on IM7/977-3 quasi-isotropic flat panels at normal incidence using micron-sized particles (i.e. less than or equal to 100 microns) of soda lime glass and olivine. Testing was performed at room temperature (RT) and 175 C with results from the 175 C test compared to those obtained at RT. Between 10 and 30 particles with velocities ranging from 5 to 13 km/s impacted each panel surface for each test temperature. Panels were ultrasonically scanned prior to and after impact testing to assess internal damage. Post-impact analysis included microscopic examination of the surface, determination of particle speed and location, and photomicroscopy for microcrack assessment. Internal damage was observed by ultrasonic inspection on panels impacted at 175 C, whereas damage for the RT impacted panels was confined to surface divets/craters as determined by microscopic analysis.

LOX/GOX mechanical impact tester assessment

NASA Technical Reports Server (NTRS)

Bransford, J. W.; Bryan, C. J.; Frye, G. W.; Stohler, S. L.

1980-01-01

The performances of three existing high pressure oxygen mechanical impact test systems were tested at two different test sites. The systems from one test site were fabricated from the same design drawing, whereas the system tested at the other site was of different design. Energy delivered to the test sample for each test system was evaluated and compared. Results were compared to the reaction rates obtained.

Fuel containment and damage tolerance in large composite primary aircraft structures. Phase 2: Testing

NASA Technical Reports Server (NTRS)

Sandifer, J. P.; Denny, A.; Wood, M. A.

1985-01-01

Technical issues associated with fuel containment and damage tolerance of composite wing structures for transport aircraft were investigated. Material evaluation tests were conducted on two toughened resin composites: Celion/HX1504 and Celion/5245. These consisted of impact, tension, compression, edge delamination, and double cantilever beam tests. Another test series was conducted on graphite/epoxy box beams simulating a wing cover to spar cap joint configuration of a pressurized fuel tank. These tests evaluated the effectiveness of sealing methods with various fastener types and spacings under fatigue loading and with pressurized fuel. Another test series evaluated the ability of the selected coatings, film, and materials to prevent fuel leakage through 32-ply AS4/2220-1 laminates at various impact energy levels. To verify the structural integrity of the technology demonstration article structural details, tests were conducted on blade stiffened panels and sections. Compression tests were performed on undamaged and impacted stiffened AS4/2220-1 panels and smaller element tests to evaluate stiffener pull-off, side load and failsafe properties. Compression tests were also performed on panels subjected to Zone 2 lightning strikes. All of these data were integrated into a demonstration article representing a moderately loaded area of a transport wing. This test combined lightning strike, pressurized fuel, impact, impact repair, fatigue and residual strength.

Assessing Willingness to Test for HIV among Men who have Sex with Men Using Conjoint Analysis, Evidence for Uptake of the FDA-approved at-Home HIV Test

PubMed Central

Lee, Sung-Jae; Brooks, Ronald; Bolan, Robert K.; Flynn, Risa

2013-01-01

Men who have sex with men (MSM) in the United States represent a vulnerable population with lower rates of HIV testing. There are various specific attributes of HIV testing that may impact willingness to test (WTT) for HIV. Identifying specific attributes influencing patients’ decisions around WTT for HIV is critical to ensure improved HIV testing uptake. This study examined WTT for HIV by using conjoint analysis, an innovative method for systematically estimating consumer preferences across discrete attributes. WTT for HIV was assessed across eight hypothetical HIV testing scenarios varying across seven dichotomous attributes: location (home vs. clinic), price (free vs. $50), sample collection (finger prick vs. blood), timeliness of results (immediate vs. 1–2 weeks), privacy (anonymous vs. confidential), results given (by phone vs. in-person), and type of counseling (brochure vs. in-person). Seventy-five MSM were recruited from a community based organization providing HIV testing services in Los Angeles to participate in conjoint analysis. WTT for HIV score was based on a 100-point scale. Scores ranged from 32.2 to 80.3 for eight hypothetical HIV testing scenarios. Price of HIV testing (free vs. $50) had the highest impact on WTT (impact score=31.4, SD=29.2, p<.0001), followed by timeliness of results (immediate vs. 1–2 weeks) (impact score=13.9, SD=19.9, p=<.0001) and testing location (home vs. clinic) (impact score=10.3, SD=22.8, p=.0002). Impacts of other HIV testing attributes were not significant. Conjoint analysis method enabled direct assessment of HIV testing preferences and identified specific attributes that significantly impact WTT for HIV among MSM. This method provided empirical evidence to support the potential uptake of the newly FDA-approved over-the-counter HIV home-test kit with immediate results, with cautionary note on the cost of the kit. PMID:23651439

Simplified Impact Testing of Traffic Barrier Systems (Phase I)

DOT National Transportation Integrated Search

2003-06-01

A simplified impact test configuration was developed to provide a preliminary, economical means of assessing prototype traffic barriers before proceeding to full-scale federal testing. Specifically, the test was configured to assess the federal crite...

75 FR 53971 - Guidance for Industry and Food and Drug Administration Staff; Impact-Resistant Lenses: Questions...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-02

... questions on impact-resistant lenses, including questions on test procedures, lens testing apparatus, record..., lens testing apparatus, record maintenance, and exemptions to testing. This document also contains more...

Anonymous HIV testing: the impact of availability on demand in Arizona.

PubMed Central

Hirano, D; Gellert, G A; Fleming, K; Boyd, D; Englender, S J; Hawks, H

1994-01-01

The purpose of this study was to evaluate the impact of anonymous testing availability on human immunodeficiency virus (HIV) test demand in Arizona. Testing patterns before and after the introduction of anonymous testing were compared. Client knowledge of new test policy and delay in testing until an anonymous option was available were assessed. Test numbers among men who have sex with men showed a statistically significant increase after introduction of an anonymous testing option. Arizona continues to maintain anonymous testing availability. Public health agencies should consider how test policy may influence people's HIV test decisions. PMID:7998649

Low velocity instrumented impact testing of four new damage tolerant carbon/epoxy composite systems

NASA Technical Reports Server (NTRS)

Lance, D. G.; Nettles, A. T.

1990-01-01

Low velocity drop weight instrumented impact testing was utilized to examine the damage resistance of four recently developed carbon fiber/epoxy resin systems. A fifth material, T300/934, for which a large data base exists, was also tested for comparison purposes. A 16-ply quasi-isotropic lay-up configuration was used for all the specimens. Force/absorbed energy-time plots were generated for each impact test. The specimens were cross-sectionally analyzed to record the damage corresponding to each impact energy level. Maximum force of impact versus impact energy plots were constructed to compare the various systems for impact damage resistance. Results show that the four new damage tolerant fiber/resin systems far outclassed the T300/934 material. The most damage tolerant material tested was the IM7/1962 fiber/resin system.

7 CFR 1755.702 - Copper coated steel reinforced (CCSR) aerial service wire.

Code of Federal Regulations, 2012 CFR

2012-01-01

... requirements—(1) Impact test. (i) All CCSR aerial service wires manufactured in accordance with this section shall comply with the unaged impact test specified in ANSI/ICEA S-89-648-1993, paragraph 8.1.2. (ii) All... impact test specified in ANSI/ICEA S-89-648-1993, paragraph 8.1.3. (2) Abrasion resistance test. All CCSR...

7 CFR 1755.702 - Copper coated steel reinforced (CCSR) aerial service wire.

Code of Federal Regulations, 2013 CFR

2013-01-01

... requirements—(1) Impact test. (i) All CCSR aerial service wires manufactured in accordance with this section shall comply with the unaged impact test specified in ANSI/ICEA S-89-648-1993, paragraph 8.1.2. (ii) All... impact test specified in ANSI/ICEA S-89-648-1993, paragraph 8.1.3. (2) Abrasion resistance test. All CCSR...

7 CFR 1755.702 - Copper coated steel reinforced (CCSR) aerial service wire.

Code of Federal Regulations, 2014 CFR

2014-01-01

... requirements—(1) Impact test. (i) All CCSR aerial service wires manufactured in accordance with this section shall comply with the unaged impact test specified in ANSI/ICEA S-89-648-1993, paragraph 8.1.2. (ii) All... impact test specified in ANSI/ICEA S-89-648-1993, paragraph 8.1.3. (2) Abrasion resistance test. All CCSR...

Is the psychological impact of genetic testing moderated by support and sharing of test results to family and friends?

PubMed

Lapointe, Julie; Dorval, Michel; Noguès, Catherine; Fabre, Roxane; Julian-Reynier, Claire

2013-12-01

Receiving the results of genetic tests for a breast and ovarian cancer susceptibility can be a stressful experience. Here we studied the effects of social support (SS) and the sharing of test results on the psychological impact of BRCA1/2 test result disclosure. We also compared carriers and non-carriers on sharing, SS and psychological impact. Five-hundred and twenty-two unaffected women were followed prospectively for 2 years after receiving their test results. Psychological impact was measured on the impact of event scale. Multivariate multi-level models were used, and all the analyses were stratified depending on mutation status (carriers vs non-carriers). Two weeks after receiving their BRCA1/2 results, carriers had shared their test results less frequently than non-carriers (p < 0.01). Sharing test results was not significantly associated with psychological impact. Availability of SS was significantly associated with better psychological adjustment across time among carriers (p < 0.01), but not among non-carriers. For female BRCA1/2 mutation carriers, the importance of SS should be stressed, and possible ways of enlisting people in their entourage for this purpose should be discussed in the context of clinical encounters.

The WRAIR projectile concussive impact model of mild traumatic brain injury: re-design, testing and preclinical validation.

PubMed

Leung, Lai Yee; Larimore, Zachary; Holmes, Larry; Cartagena, Casandra; Mountney, Andrea; Deng-Bryant, Ying; Schmid, Kara; Shear, Deborah; Tortella, Frank

2014-08-01

The WRAIR projectile concussive impact (PCI) model was developed for preclinical study of concussion. It represents a truly non-invasive closed-head injury caused by a blunt impact. The original design, however, has several drawbacks that limit the manipulation of injury parameters. The present study describes engineering advancements made to the PCI injury model including helmet material testing, projectile impact energy/head kinematics and impact location. Material testing indicated that among the tested materials, 'fiber-glass/carbon' had the lowest elastic modulus and yield stress for providing an relative high percentage of load transfer from the projectile impact, resulting in significant hippocampal astrocyte activation. Impact energy testing of small projectiles, ranging in shape and size, showed the steel sphere produced the highest impact energy and the most consistent impact characteristics. Additional tests confirmed the steel sphere produced linear and rotational motions on the rat's head while remaining within a range that meets the criteria for mTBI. Finally, impact location testing results showed that PCI targeted at the temporoparietal surface of the rat head produced the most prominent gait abnormalities. Using the parameters defined above, pilot studies were conducted to provide initial validation of the PCI model demonstrating quantifiable and significant increases in righting reflex recovery time, axonal damage and astrocyte activation following single and multiple concussions.

Demonstration of Hazardous Hypervelocity Test Capability

NASA Technical Reports Server (NTRS)

Rodriquez, Karen M.

1991-01-01

NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) participated in a joint test program with NASA JSC Hypervelocity Impact Research Laboratory (HIRL) to determine if JSC was capable of performing hypervelocity impact tests on hazardous targets. Seven pressurized vessels were evaluated under hypervelocity impact conditions. The vessels were tested with various combinations of liquids and gasses at various pressures. Results from the evaluation showed that vessels containing 100-percent pressurized gas sustained more severe damage and had a higher potential for damaging nearby equipment, than vessels containing 75-percent liquid, 25-percent inert pressurized gas. Two water-filled test vessels, one of which was placed behind an aluminum shield, failed by bulging and splitting open at the impact point; pressure was relieved without the vessel fragmenting or sustaining internal damage. An additional water-filled test vessel, placed a greater distance behind an aluminum shield, sustained damage that resembled a shotgun blast, but did not bulge or split open; again, pressure was relieved without the vessel fragmenting. Two test vessels containing volatile liquids (nitro methane and hydrazine) also failed by bulging and splitting open; neither liquid detonated under hypervelocity test conditions. A test vessel containing nitrogen gas failed by relieving pressure through a circular entry hole; multiple small penetrations opposite the point of entry provided high velocity target debris to surrounding objects. A high-pressure oxygen test vessel fragmented upon impact; the ensuing fire and high velocity fragments caused secondary damage to surrounding objects. The results from the evaluation of the pressurized vessels indicated that JSC is capable of performing hypervelocity impact tests on hazardous targets.

Neurocognitive performance and symptom profiles of Spanish-speaking Hispanic athletes on the ImPACT test.

PubMed

Ott, Summer; Schatz, Philip; Solomon, Gary; Ryan, Joseph J

2014-03-01

This study documented baseline neurocognitive performance of 23,815 athletes on the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test. Specifically, 9,733 Hispanic, Spanish-speaking athletes who completed the ImPACT test in English and 2,087 Hispanic, Spanish-speaking athletes who completed the test in Spanish were compared with 11,955 English-speaking athletes who completed the test in English. Athletes were assigned to age groups (13-15, 16-18). Results revealed a significant effect of language group (p < .001; partial η(2) = 0.06) and age (p < .001; partial η(2) = 0.01) on test performance. Younger athletes performed more poorly than older athletes, and Spanish-speaking athletes completing the test in Spanish scored more poorly than Spanish-speaking and English-speaking athletes completing the test in English, on all Composite scores and Total Symptom scores. Spanish-speaking athletes completing the test in English also performed more poorly than English-speaking athletes completing the test in English on three Composite scores. These differences in performance and reported symptoms highlight the need for caution in interpreting ImPACT test data for Hispanic Americans.

Sand Impact Tests of a Half-Scale Crew Module Boilerplate Test Article

NASA Technical Reports Server (NTRS)

Vassilakos, Gregory J.; Hardy, Robin C.

2012-01-01

Although the Orion Multi-Purpose Crew Vehicle (MPCV) is being designed primarily for water landings, a further investigation of launch abort scenarios reveals the possibility of an onshore landing at Kennedy Space Center (KSC). To gather data for correlation against simulations of beach landing impacts, a series of sand impact tests were conducted at NASA Langley Research Center (LaRC). Both vertical drop tests and swing tests with combined vertical and horizontal velocity were performed onto beds of common construction-grade sand using a geometrically scaled crew module boilerplate test article. The tests were simulated using the explicit, nonlinear, transient dynamic finite element code LS-DYNA. The material models for the sand utilized in the simulations were based on tests of sand specimens. Although the LSDYNA models provided reasonable predictions for peak accelerations, they were not always able to track the response through the duration of the impact. Further improvements to the material model used for the sand were identified based on results from the sand specimen tests.

The production of calibration specimens for impact testing of subsize Charpy specimens

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

Alexander, D.J.; Corwin, W.R.; Owings, T.D.

1994-09-01

Calibration specimens have been manufactured for checking the performance of a pendulum impact testing machine that has been configured for testing subsize specimens, both half-size (5.0 {times} 5.0 {times} 25.4 mm) and third-size (3.33 {times} 3.33 {times} 25.4 mm). Specimens were fabricated from quenched-and-tempered 4340 steel heat treated to produce different microstructures that would result in either high or low absorbed energy levels on testing. A large group of both half- and third-size specimens were tested at {minus}40{degrees}C. The results of the tests were analyzed for average value and standard deviation, and these values were used to establish calibration limitsmore » for the Charpy impact machine when testing subsize specimens. These average values plus or minus two standard deviations were set as the acceptable limits for the average of five tests for calibration of the impact testing machine.« less

Micrometeorite Impact Test of Flex Solar Array Coupon

NASA Technical Reports Server (NTRS)

Wright, K. H.; Schneider, T. A.; Vaughn, J. A.; Hoang, B.; Wong, F.; Gardiner, G.

2016-01-01

Spacecraft with solar arrays operate throughout the near earth environment and are planned for outer planet missions. An often overlooked test condition for solar arrays that is applicable to these missions is micrometeoroid impacts and possibly electrostatic discharge (ESD) events resulting from these impacts. NASA Marshall Space Flight Center (MSFC) is partnering with Space Systems/Loral, LLC (SSL) to examine the results of simulated micrometeoroid impacts on the electrical performance of an advanced, lightweight flexible solar array design. The test is performed at MSFC's Micro Light Gas Gun Facility with SSL-provided coupons. Multiple impacts were induced at various locations on a powered test coupon under different string voltage (0V-150V) and string current (1.1A - 1.65A) conditions. The setup, checkout, and results from the impact testing are discussed.

Return to Flight Resource Reel 1 of 2

NASA Technical Reports Server (NTRS)

2005-01-01

A video presentation detailing the tests performed on the Space Shuttle Discovery in preparation for its return to flight is shown. The tests include: 1) Reinforced Carbon-Carbon (RCC) Impact Test Article; 2) RCC Foam Impact Testing; 3) Thermal Protection System (TPS) Ice Impact Testing featuring Justin Kerr, Project Engineer; 4) Wing Leading Edge Wireless Sensors featuring Karl Kiefer, President and CEO of Invocon, and Kevin Champaigne of Invocon; 5) TPS Repair Testing KC-135 Zero-G Environment featuring Soichi Noguchi, Mission Specialist; 6) TPS Extravehicular Activity Tool Demonstration; 7) TPS Repair Testing Vacuum Glove box; 8) TPS Repair Testing Human Thermal Vacuum Chamber; 9) TPS Reentry Testing Atmospheric Reentry Materials and Structures Evaluation Facility; 10) TPS Alternative Repair Concept; 11) Lora Bailey Lead Engineer for EVA Tools; 12) Reinforced Carbon-Carbon ATK Thiokol Plug Repair Animation; 13) 3-Percent Model Build-Up; and 14) Wind Tunnel Testing RCC Aging Research Ballistic Testing.

The impact performance of headguards for combat sports.

PubMed

McIntosh, Andrew S; Patton, Declan A

2015-09-01

To assess the impact energy attenuation performance of a range of headguards for combat sports. Seven headguards worn during combat sport training or competition, including two Association Internationale de Boxe Amateur (AIBA)-approved boxing models, were tested using drop tests. An International Organization for Standardization (ISO) rigid headform was used with a 5.6 kg drop assembly mass. Tests were conducted against a flat rigid anvil both with and without a boxing glove section. The centre forehead and lateral headguard areas were tested. Peak headform acceleration was measured. Tests from a selection of drop heights and repeated tests on the same headguard were conducted. Headguard performance varied by test condition. For the 0.4 m rigid anvil tests, the best model headguard was the thickest producing an average peak headform acceleration over 5 tests of 48 g compared with 456 g for the worst model. The mean peak acceleration for the 0.4, 0.5 and 0.6 frontal and lateral rigid anvil impact tests was between 32% and 40% lower for the Top Ten boxing model compared with the Adidas boxing model. The headguard performance deterioration observed with repeat impact against the flat anvil was reduced for impacts against the glove section. The overall reduction in acceleration for the combination of glove and headguard in comparison to the headguard condition was in the range of 72-93% for 0.6 and 0.8 m drop tests. The impact tests show the benefits of performance testing in identifying differences between headguard models. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Responses of the Q6/Q6s ATD Positioned in Booster Seats in the Far-Side Seat Location of Side Impact Passenger Car and Sled Tests.

PubMed

Tylko, Suzanne; Bohman, Katarina; Bussières, Alain

2015-11-01

Passenger car side impact crash tests and sled tests were conducted to investigate the influence of booster seats, near-side occupant characteristics and vehicle interiors on the responses of the Q6/Q6s child ATD positioned in the rear, far-side seating location. Data from nine side impact sled tests simulating a EuroNCAP AEMD barrier test were analyzed with data obtained from 44 side impact crash tests. The crash tests included: FMVSS 214 and IIHS MDB, moving car-to-stationary car and moving car-to-moving car. A Q6 or prototype Q6s ATD was seated on the far-side, using a variety of low and high back booster seats. Head and chest responses were recorded and ATD motions were tracked with high-speed videos. The vehicle lateral accelerations resulting from MDB tests were characterized by a much earlier and more rapid rise to peak than in tests where the bullet was another car. The near-side seating position was occupied by a Hybrid III 10-year-old ATD in the sled tests, and a rear or front facing child restraint or a 5th percentile side impact ATD in the crash tests. Head impacts occurred more frequently in vehicles where a forward facing child restraint was present behind the driver seat for both the low and high back booster seats. Pretensioners were found to reduce lateral head displacements in all sled test configurations but the greatest reduction in lateral excursion was obtained with a high back booster seat secured with LATCH and tested in combination with pretensioners.

Failure mechanics in low-velocity impacts on thin composite plates

NASA Technical Reports Server (NTRS)

Elber, W.

1983-01-01

Eight-ply quasi-isotropic composite plates of Thornel 300 graphite in Narmco 5208 epoxy resin (T300/5208) were tested to establish the degree of equivalence between low-velocity impact and static testing. Both the deformation and failure mechanics under impact were representable by static indentation tests. Under low-velocity impacts such as tool drops, the dominant deformation mode of the plates was the first, or static, mode. Higher modes are excited on contact, but they decay significantly by the time the first-mode load reaches a maximum. The delamination patterns were observed by X-ray analysis. The areas of maximum delamination patterns were observed by X-ray analysis. The areas of maximum delamination coincided with the areas of highest peel stresses. The extent of delamination was similar for static and impact tests. Fiber failure damage was established by tensile tests on small fiber bundles obtained by deplying test specimens. The onset of fiber damage was in internal plies near the lower surface of the plates. The distribution and amount of fiber damage was similar fo impact and static tests.

The Potential Impact of Not Being Able to Create Parallel Tests on Expected Classification Accuracy

ERIC Educational Resources Information Center

Wyse, Adam E.

2011-01-01

In many practical testing situations, alternate test forms from the same testing program are not strictly parallel to each other and instead the test forms exhibit small psychometric differences. This article investigates the potential practical impact that these small psychometric differences can have on expected classification accuracy. Ten…

Crash Testing and Simulation of a Cessna 172 Aircraft: Pitch Down Impact Onto Soft Soil

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Jackson, Karen E.

2016-01-01

During the summer of 2015, NASA Langley Research Center conducted three full-scale crash tests of Cessna 172 (C-172) aircraft at the NASA Langley Landing and Impact Research (LandIR) Facility. The first test represented a flare-to-stall emergency or hard landing onto a rigid surface. The second test, which is the focus of this paper, represented a controlled-flight-into-terrain (CFIT) with a nose-down pitch attitude of the aircraft, which impacted onto soft soil. The third test, also conducted onto soil, represented a CFIT with a nose-up pitch attitude of the aircraft, which resulted in a tail strike condition. These three crash tests were performed for the purpose of evaluating the performance of Emergency Locator Transmitters (ELTs) and to generate impact test data for model validation. LS-DYNA finite element models were generated to simulate the three test conditions. This paper describes the model development and presents test-analysis comparisons of acceleration and velocity time-histories, as well as a comparison of the time sequence of events for Test 2 onto soft soil.

Crash Testing and Simulation of a Cessna 172 Aircraft: Hard Landing Onto Concrete

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.

2016-01-01

A full-scale crash test of a Cessna 172 aircraft was conducted at the Landing and Impact Research Facility at NASA Langley Research Center during the summer of 2015. The purpose of the test was to evaluate the performance of Emergency Locator Transmitters (ELTs) that were mounted at various locations in the aircraft and to generate impact test data for model validation. A finite element model of the aircraft was developed for execution in LSDYNA to simulate the test. Measured impact conditions were 722.4-in/s forward velocity and 276-in/s vertical velocity with a 1.5deg pitch (nose up) attitude. These conditions were intended to represent a survivable hard landing. The impact surface was concrete. During the test, the nose gear tire impacted the concrete, followed closely by impact of the main gear tires. The main landing gear spread outward, as the nose gear stroked vertically. The only fuselage contact with the impact surface was a slight impact of the rearmost portion of the lower tail. Thus, capturing the behavior of the nose and main landing gear was essential to accurately predict the response. This paper describes the model development and presents test-analysis comparisons in three categories: inertial properties, time sequence of events, and acceleration and velocity time-histories.

Hypervelocity Impact (HVI). Volume 6; WLE High Fidelity Specimen Fg(RCC)-2

NASA Technical Reports Server (NTRS)

Gorman, Michael R.; Ziola, Steven M.

2007-01-01

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Target Fg(RCC)-2 was to study hypervelocity impacts through the reinforced carbon-carbon (RCC) panels of the Wing Leading Edge. Fiberglass was used in place of RCC in the initial tests. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Hypervelocity Impact (HVI). Volume 4; WLE Small-Scale Fiberglass Panel Flat Target C-2

NASA Technical Reports Server (NTRS)

Gorman, Michael R.; Ziola, Steven M.

2007-01-01

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Target C-2 was to study impacts through the reinforced carboncarbon (RCC) panels of the Wing Leading Edge. Fiberglass was used in place of RCC in the initial tests. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Hypervelocity Impact (HVI). Volume 5; WLE High Fidelity Specimen Fg(RCC)-1

NASA Technical Reports Server (NTRS)

Gorman, Michael R.; Ziola, Steven M.

2007-01-01

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Target Fg(RCC)-1 was to study hypervelocity impacts through the reinforced carbon-carbon (RCC) panels of the Wing Leading Edge. Fiberglass was used in place of RCC in the initial tests. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Hypervelocity Impact (HVI). Volume 3; WLE Small-Scale Fiberglass Panel Flat Target C-1

NASA Technical Reports Server (NTRS)

Gorman, Michael R.; Ziola, Steven M.

2007-01-01

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Target C-1 was to study hypervelocity impacts on the reinforced carbon-carbon (RCC) panels of the Wing Leading Edge. Fiberglass was used in place of RCC in the initial tests. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Instrumented impact and residual tensile strength testing of eight-ply carbon eopoxy specimens

NASA Technical Reports Server (NTRS)

Nettles, A. T.

1990-01-01

Instrumented drop weight impact testing was utilized to examine a puncture-type impact on thin carbon-epoxy coupons. Four different material systems with various eight-ply lay-up configurations were tested. Specimens were placed over a 10.3-mm diameter hole and impacted with a smaller tup (4.2-mm diameter) than those used in previous studies. Force-time plots as well as data on absorbed energy and residual tensile strength were gathered and examined. It was found that a critical impact energy level existed for each material tested, at which point tensile strength began to rapidly decrease with increasing impact energy.

A new tensile impact test for the toughness characterization of sheet material

NASA Astrophysics Data System (ADS)

Könemann, Markus; Lenz, David; Brinnel, Victoria; Münstermann, Sebastian

2018-05-01

In the past, the selection of suitable steels has been carried out primarily based on the mechanical properties of different steels. One of these properties is the resistance against crack propagation. For many constructions, this value plays an important role, because it can compare the impact toughness of different steel grades easily and gives information about the loading capacity of the specific materials. For thin sheets, impact toughness properties were usually not considered. One of the reasons for this is that the Charpy-impact test is not applicable for sheets with thicknesses below 2 mm. For a long time, this was not relevant because conventional steels had a sufficient impact toughness in a wide temperature range. However, since new multiphase steel grades with improved mechanical property exploitations are available, it turned out that impact toughness properties need to be considered during the component design phase, as the activation of the cleavage fracture mechanism is observed under challenging loading conditions. Therefore, this work aims to provide a new and practical testing procedure for sheet material or thin walled structures. The new testing procedure is based on tensile tests conducted in an impact pendulum similar to the Charpy impact hammer. A new standard geometry is provided, which enables a comparison between different steels or steel grades. A connection to the conventional Charpy test is presented using a damage mechanics model, which predicts material failure with consideration of to the stress state at various temperatures. Different specimen geometries are analysed to cover manifold stress states. A special advantage of the damage mechanics model is also the possibility to predict the materials behaviour in the transition area. To verify the method a conventional steel was tested in Charpy tests as well as in the new tensile impact test.

Test Directions as a Critical Component of Test Design: Best Practices and the Impact of Examinee Characteristics

ERIC Educational Resources Information Center

Lakin, Joni M.

2014-01-01

The purpose of test directions is to familiarize examinees with a test so that they respond to items in the manner intended. However, changes in educational measurement as well as the U.S. student population present new challenges to test directions and increase the impact that differential familiarity could have on the validity of test score…

Detailed modeling of the train-to-train impact test : rail passenger equipment impact tests

DOT National Transportation Integrated Search

2007-07-01

This report describes the results of a finite element-based analysis of the train-to-train impact test conducted at the Federal Railroad Administrations Transportation Technology Center in Pueblo, CO, on January 31, 2002. The ABAQUS/Explicit dynam...

Impact fuze testing at 3000 m/sec employing explosively accelerating plates

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

Gill, W.

1981-01-01

The Explosives Testing Division at Sandia has developed a method of simulating a re-entry vehicle impacting the ground. The purpose of the simulation is to evaluate different fusing concepts. The design and operation of this impact testing facility are described.

Examination of the Test-Retest Reliability of a Computerized Neurocognitive Test Battery.

PubMed

Nakayama, Yusuke; Covassin, Tracey; Schatz, Philip; Nogle, Sally; Kovan, Jeff

2014-08-01

Test-retest reliability is a critical issue in the utility of computer-based neurocognitive assessment paradigms employing baseline and postconcussion tests. Researchers have reported low test-retest reliability for the Immediate Post Concussion Assessment and Cognitive Testing (ImPACT) across an interval of 45 and 50 days. To re-examine the test-retest reliability of the ImPACT between baseline, 45 days, and 50 days. Descriptive laboratory study. Eighty-five physically active college students (51 male, 34 female) volunteered for this study. Participants completed the ImPACT as well as a 15-item memory test at baseline, 45 days, and 50 days. Intraclass correlation coefficients (ICCs) were calculated for ImPACT composite scores, and change scores were calculated using reliable change indices (RCIs) and regression-based methods (RBMs) at 80% and 95% confidence intervals (CIs). The respective ICCs for baseline to day 45, day 45 to day 50, baseline to day 50, and overall were as follows: verbal memory (0.76, 0.69, 0.65, and 0.78), visual memory (0.72, 0.66, 0.60, and 0.74), visual motor (processing) speed (0.87, 0.88, 0.85, and 0.91), and reaction time (0.67, 0.81, 0.71, and 0.80). All ICCs exceeded the threshold value of 0.60 for acceptable test-retest reliability. All cases fell well within the 80% CI for both the RCI and RBM, while 1% to 5% of cases fell outside the 95% CI for the RCI and 1% for the RBM. Results suggest that the ImPACT is a reliable neurocognitive test battery at 45 and 50 days after the baseline assessment. The current findings agree with those of other reliability studies that have reported acceptable ICCs across 30-day to 1-year testing intervals, and they support the utility of the ImPACT for the multidisciplinary approach to concussion management. This study suggests that the computerized neurocognitive test battery, ImPACT, is a reliable test for postconcussion serial assessments. However, when managing concussed athletes, the ImPACT should not be used as a stand-alone measure. © 2014 The Author(s).

A Comparative Analysis of Two Full-Scale MD-500 Helicopter Crash Tests

NASA Technical Reports Server (NTRS)

Littell, Justin D.

2011-01-01

Two full scale crash tests were conducted on a small MD-500 helicopter at NASA Langley Research Center fs Landing and Impact Research Facility. One of the objectives of this test series was to compare airframe impact response and occupant injury data between a test which outfitted the airframe with an external composite passive energy absorbing honeycomb and a test which had no energy absorbing features. In both tests, the nominal impact velocity conditions were 7.92 m/sec (26 ft/sec) vertical and 12.2 m/sec (40 ft/sec) horizontal, and the test article weighed approximately 1315 kg (2900 lbs). Airframe instrumentation included accelerometers and strain gages. Four Anthropomorphic Test Devices were also onboard; three of which were standard Hybrid II and III, while the fourth was a specialized torso. The test which contained the energy absorbing honeycomb showed vertical impact acceleration loads of approximately 15 g, low risk for occupant injury probability, and minimal airframe damage. These results were contrasted with the test conducted without the energy absorbing honeycomb. The test results showed airframe accelerations of approximately 40 g in the vertical direction, high risk for injury probability in the occupants, and substantial airframe damage.

Orion Ground Test Article Water Impact Tests: Photogrammetric Evaluation of Impact Conditions

NASA Technical Reports Server (NTRS)

Vassilakos, Gregory J.; Mark, Stephen D.

2018-01-01

The Ground Test Article (GTA) is an early production version of the Orion Crew Module (CM). The structural design of the Orion CM is being developed based on LS-DYNA water landing simulations. As part of the process of confirming the accuracy of LS-DYNA water landing simulations, the GTA water impact test series was conducted at NASA Langley Research Center (LaRC) to gather data for comparison with simulations. The simulation of the GTA water impact tests requires the accurate determination of the impact conditions. To accomplish this, the GTA was outfitted with an array of photogrammetry targets. The photogrammetry system utilizes images from two cameras with a specialized tracking software to determine time histories for the 3-D coordinates of each target. The impact conditions can then be determined from the target location data.

Public health and clinical impact of increasing emergency department-based HIV testing: perspectives from the 2007 conference of the National Emergency Department HIV Testing Consortium.

PubMed

Kecojevic, Aleksandar; Lindsell, Christopher J; Lyons, Michael S; Holtgrave, David; Torres, Gretchen; Heffelfinger, James; Brown, Jeremy; Couture, Eileen; Jung, Julianna; Connell, Samantha; Rothman, Richard E

2011-07-01

Understanding perceived benefits and disadvantages of HIV testing in emergency departments (EDs) is imperative to overcoming barriers to implementation. We codify those domains of public health and clinical care most affected by implementing HIV testing in EDs, as determined by expert opinion. Opinions were systematically collected from attendees of the 2007 National ED HIV Testing Consortium meeting. Structured evaluation of strengths, weaknesses, opportunities, and threats analysis was conducted to assess the impact of ED-based HIV testing on public health. A modified Delphi method was used to assess the impact of ED-based HIV testing on clinical care from both individual patient and individual provider perspectives. Opinions were provided by 98 experts representing 42 academic and nonacademic institutions. Factors most frequently perceived to affect public health were (strengths) high volume of ED visits and high prevalence of HIV, (weaknesses) undue burden on EDs, (opportunities) reduction of HIV stigma, and (threats) lack of resources in EDs. Diagnostic testing and screening for HIV were considered to have a favorable impact on ED clinical care from both individual patient and individual provider perspectives; however, negative test results were not perceived to have any benefit from the provider's perspective. The need for HIV counseling in the ED was considered to have a negative impact on clinical care from the provider's perspective. Experts in ED-based HIV testing perceived expanded ED HIV testing to have beneficial impacts for both the public health and individual clinical care; however, limited resources were frequently cited as a possible impediment. Many issues must be resolved through further study, education, and policy changes if the full potential of HIV testing in EDs is to be realized. Copyright © 2011. Published by Mosby, Inc.

49 CFR 572.74 - Thorax assembly and test procedure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... by a test probe conforming to § 572.77(a) to 20 ±0.3 fps according to the test procedure in paragraph... longitudinal center line of the test probe so that it coincides with the designated impact point, and align the test probe so that at impact, the probe's longitudinal center line coincides (within 2 degrees) with...

49 CFR 572.74 - Thorax assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... by a test probe conforming to § 572.77(a) to 20 ±0.3 fps according to the test procedure in paragraph... longitudinal center line of the test probe so that it coincides with the designated impact point, and align the test probe so that at impact, the probe's longitudinal center line coincides (within 2 degrees) with...

49 CFR 572.74 - Thorax assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... by a test probe conforming to § 572.77(a) to 20 ±0.3 fps according to the test procedure in paragraph... longitudinal center line of the test probe so that it coincides with the designated impact point, and align the test probe so that at impact, the probe's longitudinal center line coincides (within 2 degrees) with...

49 CFR 572.74 - Thorax assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... by a test probe conforming to § 572.77(a) to 20 ±0.3 fps according to the test procedure in paragraph... longitudinal center line of the test probe so that it coincides with the designated impact point, and align the test probe so that at impact, the probe's longitudinal center line coincides (within 2 degrees) with...

49 CFR 572.74 - Thorax assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... by a test probe conforming to § 572.77(a) to 20 ±0.3 fps according to the test procedure in paragraph... longitudinal center line of the test probe so that it coincides with the designated impact point, and align the test probe so that at impact, the probe's longitudinal center line coincides (within 2 degrees) with...

Preparation of calibrated test packages for particle impact noise detection

NASA Technical Reports Server (NTRS)

1977-01-01

A standard calibration method for any particle impact noise detection (PIND) test system used to detect loose particles responsible for failures in hybrid circuits was developed along with a procedure for preparing PIND standard test devices. Hybrid packages were seeded with a single gold ball, hermetically sealed, leak tested, and PIND tested. Conclusions are presented.

The Impact of Personality and Test Conditions on Mathematical Test Performance

ERIC Educational Resources Information Center

Hayes, Heather; Embretson, Susan E.

2013-01-01

Online and on-demand tests are increasingly used in assessment. Although the main focus has been cheating and test security (e.g., Selwyn, 2008) the cross-setting equivalence of scores as a function of contrasting test conditions is also an issue that warrants attention. In this study, the impact of environmental and cognitive distractions, as…

The use of impact force as a scale parameter for the impact response of composite laminates

NASA Technical Reports Server (NTRS)

Jackson, Wade C.; Poe, C. C., Jr.

1992-01-01

The building block approach is currently used to design composite structures. With this approach, the data from coupon tests is scaled up to determine the design of a structure. Current standard impact tests and methods of relating test data to other structures are not generally understood and are often used improperly. A methodology is outlined for using impact force as a scale parameter for delamination damage for impacts of simple plates. Dynamic analyses were used to define ranges of plate parameters and impact parameters where quasi-static analyses are valid. These ranges include most low velocity impacts where the mass of the impacter is large and the size of the specimen is small. For large mass impacts of moderately thick (0.35 to 0.70 cm) laminates, the maximum extent of delamination damage increased with increasing impact force and decreasing specimen thickness. For large mass impact tests at a given kinetic energy, impact force and hence delamination size depends on specimen size, specimen thickness, boundary conditions, and indenter size and shape. If damage is reported in terms of impact force instead of kinetic energy, large mass test results can be applied directly to other plates of the same size.

The use of impact force as a scale parameter for the impact response of composite laminates

NASA Technical Reports Server (NTRS)

Jackson, Wade C.; Poe, C. C., Jr.

1992-01-01

The building block approach is currently used to design composite structures. With this approach, the data from coupon tests are scaled up to determine the design of a structure. Current standard impact tests and methods of relating test data to other structures are not generally understood and are often used improperly. A methodology is outlined for using impact force as a scale parameter for delamination damage for impacts of simple plates. Dynamic analyses were used to define ranges of plate parameters and impact parameters where quasi-static analyses are valid. These ranges include most low-velocity impacts where the mass of the impacter is large, and the size of the specimen is small. For large-mass impacts of moderately thick (0.35-0.70 cm) laminates, the maximum extent of delamination damage increased with increasing impact force and decreasing specimen thickness. For large-mass impact tests at a given kinetic energy, impact force and hence delamination size depends on specimen size, specimen thickness, boundary conditions, and indenter size and shape. If damage is reported in terms of impact force instead of kinetic energy, large-mass test results can be applied directly to other plates of the same thickness.

Design and construction of a full-scale lateral impact testing facility.

DOT National Transportation Integrated Search

2015-05-01

The goal of this work is to design and construct a full scale lateral impact testing facility that is capable of recreating the damage that would be created by an overheight vehicle collision. This was accomplished by impacting a test specimen with 8...

49 CFR 581.7 - Test procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Test procedures. 581.7 Section 581.7... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) BUMPER STANDARD § 581.7 Test procedures. (a) Longitudinal impact test procedures. (1) Impact the vehicle's front surface and its rear surface two times each...

49 CFR 581.7 - Test procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Test procedures. 581.7 Section 581.7... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) BUMPER STANDARD § 581.7 Test procedures. (a) Longitudinal impact test procedures. (1) Impact the vehicle's front surface and its rear surface two times each...

Single passenger rail car impact test. Volume 3 : test procedures, instrumentation and data : rail passenger equipment collision tests

DOT National Transportation Integrated Search

2000-05-24

A full-scale impact test was performed November 16, 1999, at the Federal Railroad Administration's Transportation Technology Center, Pueblo, Colorado, by Transportation Technology Center, Inc., a subsidiary of the Association of American Railroads. T...

49 CFR 581.7 - Test procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Test procedures. 581.7 Section 581.7... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) BUMPER STANDARD § 581.7 Test procedures. (a) Longitudinal impact test procedures. (1) Impact the vehicle's front surface and its rear surface two times each...

Impact Testing and Simulation of Composite Airframe Structures

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Littell, Justin D.; Horta, Lucas G.; Annett, Martin S.; Fasanella, Edwin L.; Seal, Michael D., II

2014-01-01

Dynamic tests were performed at NASA Langley Research Center on composite airframe structural components of increasing complexity to evaluate their energy absorption behavior when subjected to impact loading. A second objective was to assess the capabilities of predicting the dynamic response of composite airframe structures, including damage initiation and progression, using a state-of-the-art nonlinear, explicit transient dynamic finite element code, LS-DYNA. The test specimens were extracted from a previously tested composite prototype fuselage section developed and manufactured by Sikorsky Aircraft Corporation under the US Army's Survivable Affordable Repairable Airframe Program (SARAP). Laminate characterization testing was conducted in tension and compression. In addition, dynamic impact tests were performed on several components, including I-beams, T-sections, and cruciform sections. Finally, tests were conducted on two full-scale components including a subfloor section and a framed fuselage section. These tests included a modal vibration and longitudinal impact test of the subfloor section and a quasi-static, modal vibration, and vertical drop test of the framed fuselage section. Most of the test articles were manufactured of graphite unidirectional tape composite with a thermoplastic resin system. However, the framed fuselage section was constructed primarily of a plain weave graphite fabric material with a thermoset resin system. Test data were collected from instrumentation such as accelerometers and strain gages and from full-field photogrammetry.

Hypervelocity impact testing of spacecraft optical sensors

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

NONE

Hypervelocity tests of spacecraft optical sensors were conducted to determine if the optical signature from an impact inside the optical sensor sunshade resembled signals that have been observed on-orbit. Impact tests were conducted in darkness and with the ejected debris illuminated. The tests were conducted at the Johnson Space Center Hypervelocity Impact Test Facility. The projectile masses and velocities that may be obtained at the facility are most representative of the hypervelocity particles thought to be responsible for a group of anomalous optical sensors responses that have been observed on-orbit. The projectiles are a few micrograms, slightly more massive thanmore » the microgram particles thought to be responsible for the signal source. The test velocities were typically 7.3 km/s, which are somewhat slower than typical space particles.« less

Damage Tolerance of Pre-Stressed Composite Panels Under Impact Loads

NASA Astrophysics Data System (ADS)

Johnson, Alastair F.; Toso-Pentecôte, Nathalie; Schueler, Dominik

2014-02-01

An experimental test campaign studied the structural integrity of carbon fibre/epoxy panels preloaded in tension or compression then subjected to gas gun impact tests causing significant damage. The test programme used representative composite aircraft fuselage panels composed of aerospace carbon fibre toughened epoxy prepreg laminates. Preload levels in tension were representative of design limit loads for fuselage panels of this size, and maximum compression preloads were in the post-buckle region. Two main impact scenarios were considered: notch damage from a 12 mm steel cube projectile, at velocities in the range 93-136 m/s; blunt impact damage from 25 mm diameter glass balls, at velocities 64-86 m/s. The combined influence of preload and impact damage on panel residual strengths was measured and results analysed in the context of damage tolerance requirements for composite aircraft panels. The tests showed structural integrity well above design limit loads for composite panels preloaded in tension and compression with visible notch impact damage from hard body impact tests. However, blunt impact tests on buckled compression loaded panels caused large delamination damage regions which lowered plate bending stiffness and reduced significantly compression strengths in buckling.

Indentation-flexure and low-velocity impact damage in graphite/epoxy laminates

NASA Technical Reports Server (NTRS)

Kwon, Young S.; Sankar, Bhavani V.

1992-01-01

Static indentation and low velocity impact tests were performed on quasi-isotropic and cross ply graphite/epoxy composite laminates. The load deflection relations in static tests and impact force history in the impact tests were recorded. The damage was assessed by using ultrasonic C-scanning and photomicrographic techniques. The static behavior of the laminates and damage progression during loading, unloading, and reloading were explained by a simple plate delamination model. A good correlation existed between the static and impact responses. It was found that results from a few static indentation-flexture tests can be used to predict the response and damage in composite laminates due to a class of low velocity impact events.

Finite Element Simulation of Three Full-Scale Crash Tests for Cessna 172 Aircraft

NASA Technical Reports Server (NTRS)

Mason, Brian H.; Warren, Jerry E., Jr.

2017-01-01

The NASA Emergency Locator Transmitter Survivability and Reliability (ELT-SAR) project was initiated in 2013 to assess the crash performance standards for the next generation of emergency locator transmitter (ELT) systems. Three Cessna 172 aircraft were acquired to perform crash testing at NASA Langley Research Center's Landing and Impact Research Facility. Full-scale crash tests were conducted in the summer of 2015 and each test article was subjected to severe, but survivable, impact conditions including a flare-to-stall during emergency landing, and two controlled-flight-into-terrain scenarios. Full-scale finite element analyses were performed using a commercial explicit solver, ABAQUS. The first test simulated impacting a concrete surface represented analytically by a rigid plane. Tests 2 and 3 simulated impacting a dirt surface represented analytically by an Eulerian grid of brick elements using a Mohr-Coulomb material model. The objective of this paper is to summarize the test and analysis results for the three full-scale crash tests. Simulation models of the airframe which correlate well with the tests are needed for future studies of alternate ELT mounting configurations.

49 CFR 572.180 - Incorporated materials.

Code of Federal Regulations, 2012 CFR

2012-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 2re Side Impact Crash Test... 50th Percentile Adult Male Side Impact Crash Test Dummy, February 2008,” incorporated by reference in...

Factors Influencing Ball-Player Impact Probability in Youth Baseball

PubMed Central

Matta, Philip A.; Myers, Joseph B.; Sawicki, Gregory S.

2015-01-01

Background: Altering the weight of baseballs for youth play has been studied out of concern for player safety. Research has shown that decreasing the weight of baseballs may limit the severity of both chronic arm and collision injuries. Unfortunately, reducing the weight of the ball also increases its exit velocity, leaving pitchers and nonpitchers with less time to defend themselves. The purpose of this study was to examine impact probability for pitchers and nonpitchers. Hypothesis: Reducing the available time to respond by 10% (expected from reducing ball weight from 142 g to 113 g) would increase impact probability for pitchers and nonpitchers, and players’ mean simple response time would be a primary predictor of impact probability for all participants. Study Design: Nineteen subjects between the ages of 9 and 13 years performed 3 experiments in a controlled laboratory setting: a simple response time test, an avoidance response time test, and a pitching response time test. Methods: Each subject performed these tests in order. The simple reaction time test tested the subjects’ mean simple response time, the avoidance reaction time test tested the subjects’ ability to avoid a simulated batted ball as a fielder, and the pitching reaction time test tested the subjects’ ability to avoid a simulated batted ball as a pitcher. Results: Reducing the weight of a standard baseball from 142 g to 113 g led to a less than 5% increase in impact probability for nonpitchers. However, the results indicate that the impact probability for pitchers could increase by more than 25%. Conclusion: Pitching may greatly increase the amount of time needed to react and defend oneself from a batted ball. Clinical Relevance: Impact injuries to youth baseball players may increase if a 113-g ball is used. PMID:25984261

49 CFR 572.181 - General description.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES ES-2re Side Impact Crash Test Dummy, 50th Percentile Adult Male § 572.181 General description. (a) The ES-2re Side Impact Crash... (PADI) of the ES-2re Side Impact Crash Test Dummy, February 2008, incorporated by reference, see § 572...

49 CFR 572.181 - General description.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES ES-2re Side Impact Crash Test Dummy, 50th Percentile Adult Male § 572.181 General description. (a) The ES-2re Side Impact Crash... (PADI) of the ES-2re Side Impact Crash Test Dummy, February 2008, incorporated by reference, see § 572...

14 CFR 35.36 - Bird impact.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: PROPELLERS Tests and Inspections § 35.36 Bird impact. The applicant must demonstrate, by tests or analysis based on tests or experience on similar designs, that the propeller can withstand the impact of a... without causing a major or hazardous propeller effect. This section does not apply to fixed-pitch wood...

14 CFR 35.36 - Bird impact.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: PROPELLERS Tests and Inspections § 35.36 Bird impact. The applicant must demonstrate, by tests or analysis based on tests or experience on similar designs, that the propeller can withstand the impact of a... without causing a major or hazardous propeller effect. This section does not apply to fixed-pitch wood...

14 CFR 35.36 - Bird impact.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: PROPELLERS Tests and Inspections § 35.36 Bird impact. The applicant must demonstrate, by tests or analysis based on tests or experience on similar designs, that the propeller can withstand the impact of a... without causing a major or hazardous propeller effect. This section does not apply to fixed-pitch wood...

Crash energy management : one- and two-car passenger rail impact tests - summary of structural and occupant test results

DOT National Transportation Integrated Search

2016-12-01

Two full-scale impact tests were conducted to measure the crashworthiness performance of Crash Energy Management (CEM) equipped passenger rail cars. On December 3, 2003, a single car impacted a fixed barrier at approximately 35 mph and on February 26...

IADC Vulnerability Report, IT32-13

NASA Technical Reports Server (NTRS)

Christiansen, E. L.; Miller, J. E.; Hyde, Jimx

2016-01-01

This section provides hypervelocity impact test data for two types of batteries: Lithium-Ion (Li-Ion) and Nickel Hydrogen (Ni-H2) batteries. The impact tests were directed by the NASA Johnson Space Center Hypervelocity Impact Technology (HVIT) group in Houston Texas, and were performed at the NASA White Sands Test Facility (WSTF).

Passenger cab car grade crossing impact test report : rail passenger equipment impact tests

DOT National Transportation Integrated Search

2007-10-01

Two full-scale oblique grade crossing impact tests were conducted in June 2002 to compare the crashworthiness performance of alternative corner post designs on rail passenger cab cars. On June 4, 2002, a cab car fitted with an end frame built to pre-...

Vertical Impact Tests of a Modified F/FB-111 Crew Seat to Evaluate Headrest Position and Restraint Configuration Effects

DTIC Science & Technology

1982-08-01

Deceleration Tower (VDT), shown in Figure 9, was used for this impact test series. This facility consists of a 60 ft vertical steel tower, which supports a...to void prior to entering the test area. A disposable dental bite block (made of Optosil placed over a stainless steel frame) was molded for the...shoulder strap - lap belt configuration (Sections 4D, 5C). 6. Subtolerance human impact tests can be an effective tool in the investi- gation of impact

The Effectiveness of the Component Impact Test Method for the Side Impact Injury Assessment of the Door Trim

NASA Astrophysics Data System (ADS)

Youn, Younghan; Koo, Jeong-Seo

The complete evaluation of the side vehicle structure and the occupant protection is only possible by means of the full scale side impact crash test. But, auto part manufacturers such as door trim makers can not conduct the test especially when the vehicle is under the developing process. The main objective of this study is to obtain the design guidelines by a simple component level impact test. The relationship between the target absorption energy and impactor speed were examined using the energy absorbed by the door trim. Since each different vehicle type required different energy levels on the door trim. A simple impact test method was developed to estimate abdominal injury by measuring reaction force of the impactor. The reaction force will be converted to a certain level of the energy by the proposed formula. The target of absorption energy for door trim only and the impact speed of simple impactor are derived theoretically based on the conservation of energy. With calculated speed of dummy and the effective mass of abdomen, the energy allocated in the abdomen area of door trim was calculated. The impactor speed can be calculated based on the equivalent energy of door trim absorbed during the full crash test. With the proposed design procedure for the door trim by a simple impact test method was demonstrated to evaluate the abdominal injury. This paper describes a study that was conducted to determine sensitivity of several design factors for reducing abdominal injury values using the matrix of orthogonal array method. In conclusion, with theoretical considerations and empirical test data, the main objective, standardization of door trim design using the simple impact test method was established.

Cycom 977-2 Composite Material: Impact Test Results (workshop presentation)

NASA Technical Reports Server (NTRS)

Engle, Carl; Herald, Stephen; Watkins, Casey

2005-01-01

Contents include the following: Ambient (13A) tests of Cycom 977-2 impact characteristics by the Brucenton and statistical method at MSFC and WSTF. Repeat (13A) tests of tested Cycom from phase I at MSFC to expended testing statistical database. Conduct high-pressure tests (13B) in liquid oxygen (LOX) and GOX at MSFC and WSTF to determine Cycom reaction characteristics and batch effect. Conduct expended ambient (13A) LOX test at MSFC and high-pressure (13B) testing to determine pressure effects in LOX. Expend 13B GOX database.

Characterization of Triaxial Braided Composite Material Properties for Impact Simulation

NASA Technical Reports Server (NTRS)

Roberts, Gary D.; Goldberg, Robert K.; Biniendak, Wieslaw K.; Arnold, William A.; Littell, Justin D.; Kohlman, Lee W.

2009-01-01

The reliability of impact simulations for aircraft components made with triaxial braided carbon fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Improvements to standard quasi-static test methods are needed to account for the large unit cell size and localized damage within the unit cell. The deformation and damage of a triaxial braided composite material was examined using standard quasi-static in-plane tension, compression, and shear tests. Some modifications to standard test specimen geometries are suggested, and methods for measuring the local strain at the onset of failure within the braid unit cell are presented. Deformation and damage at higher strain rates is examined using ballistic impact tests on 61- by 61- by 3.2-mm (24- by 24- by 0.125-in.) composite panels. Digital image correlation techniques were used to examine full-field deformation and damage during both quasi-static and impact tests. An impact analysis method is presented that utilizes both local and global deformation and failure information from the quasi-static tests as input for impact simulations. Improvements that are needed in test and analysis methods for better predictive capability are examined.

Preliminary Characterization Results from the DebriSat Project

NASA Technical Reports Server (NTRS)

Rivero, M.; Shiotani, B.; Kleespies, J.; Toledo-Burdett, R.; Moraguez, M.; Carrasquila, M.; Fitz-Coy, N.; Liou, J.-C.; Sorge, M.; Huynh, T.

2016-01-01

The DebriSat project is a continuing effort sponsored by NASA and DoD to update existing break-up models using data obtained from two separate hypervelocity impact tests used to simulate on-orbit collisions. To protect the fragments resulting from the impact tests, "soft-catch" arenas made of polyurethane foam panels were utilized. After each impact test, the test chamber was cleaned and debris resulting from the catastrophic demise of the test article were collected and shipped to the University of Florida for post-impact processing. The post-impact processing activities include collecting, characterizing, and cataloging of the fragments. Since the impact tests, a team of students has been working to characterize the fragments in terms of their mass, size, shape, color and material content. The focus of the 20 months since the impact tests has been on the collection of 2 millimeters- and larger fragments resulting from impact test on the 56 kilogram-representative LEO (Low Earth Orbit) satellite referred to as DebriSat. To date we have recovered in excess of 115,000 fragments, 30,000 more than the prediction of 85,000 fragments from the existing model. We continue to collect fragments but have transitioned to the characterization phase of the post-impact activities. Since the start of the characterization phase, the focus has been to utilize automation to (i) expedite fragment characterization process and (ii) minimize human-in-the- loop. We have developed and implemented such automated processes; e.g., we have automated the data entry process to reduce operator errors during transcription of the measurement data. However, at all steps of the process, there is human oversight to ensure the integrity of the data. Additionally, we have developed and implemented repeatability and reproducibility tests to ensure that the instrumentation used in the characterization process is accurate and properly calibrated. In this paper, the implemented processes are described and preliminary results presented. Additionally, lessons learned from the implemented automations and their impacts on the integrity of the results are discussed.

Failure mechanism of coated biomaterials under high impact-sliding contact stresses

NASA Astrophysics Data System (ADS)

Chen, Ying

This study uses a newly developed testing method--- inclined cyclic impact-sliding test to investigate the failure behaviors of different types of biomaterials, (SS316L, Ti6Al4V and CoCr) coated by different coatings (TiN, DLC and PEO), under extremely high dynamic contact stress conditions. This test method can simulate the combined impact and sliding/rolling loading conditions, which is very practical in many aspects of commercial usages. During the tests, fatigue cracking, chipping, peeling and material transferring were observed in damaged area. This research is mainly focused on the failure behaviors of load-bearing materials which cyclic impacting and sliding are always involved. This purpose was accomplished in the three stages: First, impact-sliding test was carried out on TiN coated unhardened M2. It was found that soft substrate can cause early failure of coating due to the considerable plastic deformation in the substrate. In this case, stronger substrate is required to support coating better when tested under high contact stresses. Second, PEO coated Ti-6Al-4V was tested under pure sliding and impact-sliding wear conditions. PEO coating was found not strong enough to afford the high contact pressure under cyclic impact-sliding wear test due to its porous surface structure. However, the wear performance of PEO coating was enhanced due to the sub-stoichiometric oxide. To sum up, for load-bearing biomedical implants involved in high impacting movement, PEO coating may not be a promising surface protection. Third, the dense, smooth PVD/CVD bio-inert coatings were reconsidered. DLC and TiN coatings, combined by different substrates together with different interface materials were tested under the cyclic impact-sliding test using a set of proper loading. The results show that to choose a proper combination of coating, interface and substrate based on their mechanical properties is of great importance under the test condition. Hard substrates provide support to coating better and a ductile and adhesive interface layer can delay the cracked coating from peeled-off.

Teaching to and beyond the Test: The Influence of Mandated Accountability Testing in One Social Studies Teacher's Classroom

ERIC Educational Resources Information Center

Neumann, Jacob

2013-01-01

Background/Context: The nature of the impact of state-mandated accountability testing on teachers' classroom practices remains contested. While many researchers argue that teachers change their teaching in response to mandated testing, others contend that the nature and degree of the impact of testing on teaching remains unclear. The research on…

Methods Used in Economic Evaluations of Testing and Diagnosis for Ovarian Cancer: A Systematic Review.

PubMed

Sharma, Vishal; Sundar, Sudha S; Breheny, Katie; Monahan, Mark; Sutton, Andrew John

2016-06-01

There are multiple tests available that can help diagnose ovarian cancer, and the cost-effective analysis of these diagnostic interventions is essential for making well-informed decisions regarding resource allocation. There are multiple factors that can impact on the conclusions drawn from economic evaluations including test accuracy, the impact of the testing pathway on patient costs and outcomes, and delays along the ovarian cancer test-treat pathway. The objective of this study was to evaluate how test accuracy, the choice of perspective, and delays along the testing and diagnostic pathway have been incorporated in economic evaluations of testing for ovarian cancer. A systematic review of published literature was undertaken to identify economic evaluations (eg, cost-effectiveness, cost-utility analysis) focused on testing and diagnosis for ovarian cancer. Seven studies met the inclusion criteria. Six studies incorporated test accuracy and its impact on patients to some extent. Four studies adopted a societal perspective, but only one considered the costs incurred by patients on the testing and diagnosis pathway. Where delays on the testing pathway were incorporated into the analysis, these were frequently due to false-negative test results leading to delays in patients accessing treatment. Any anxiety that patients might experience as a result of a positive test was not considered in these studies. The impact on patients of receiving a positive test in terms of anxiety and the costs incurred by patients having to attend for testing and diagnosis are rarely considered. Delays along the testing and diagnosis pathway can have a major effect on patient outcomes, and it is important that these are acknowledged in economic evaluations focused on testing. Future economic analysis should incorporate these key determinants in order that diagnostic tests for ovarian cancer can be robustly evaluated.

Metallurgical Examination of Failed T-158 Cast Austempered Ductile Iron (CADI) Track Shoes

DTIC Science & Technology

1994-06-01

hardness testing, fracture toughness testing and Charpy impact testing were performed. In each case, the largest possible specimens were fabricated...However, due to geometrical restrictions, the tensile, fracture toughness and impact specimens were subsized . Tensile Testing Tensile coupons were...at 5OOoF for 4 hours. Mag. 1000x. 36 ‘_ Fracture Face A bolt holes Fracture Face C T = Tensile FT = Fracture Toughness NC =Notched Charpy Impact UN

Abdomen Impact Testing of the Hybrid III Rail Safety (H3-RS) Anthropomorphic Test Device

DOT National Transportation Integrated Search

2017-09-01

The Hybrid III Rail Safety (H3-RS) anthropomorphic test device (ATD) is a crash test dummy that was developed in the UK to evaluate abdomen and lower thorax injuries that occur when passengers impact workstation tables during train accidents. The H3-...

Evaluation of cricket helmet performance and comparison with baseball and ice hockey helmets.

PubMed

McIntosh, A S; Janda, D

2003-08-01

Protective helmets in sport are important for reducing the risk of head and facial injury. In cricket and other sports with projectiles, national test standards control the minimum helmet performance. However, there are few field data showing if helmets are effective in reducing head injury. (a) To examine the performance of cricket helmets in laboratory tests; (b) to examine performance with regard to test standards, game hazards, and helmet construction; (c) to compare and contrast these findings with baseball and ice hockey helmets. Impact tests were conducted on a selection of helmet models: five cricket, two baseball, and two ice hockey. Ball to helmet impacts at speeds of 19, 27, 36, and 45 m/s were produced using an air cannon and a Hybrid III dummy headform and neck unit. Free fall drop tests with a rigid headform on to a selection of anvils (flat rigid, flat deformable, and hemispherical rigid) were conducted. Resultant headform acceleration was measured and compared between tests. At the lower speed impacts, all helmets produced a good reduction in headform acceleration, and thus injury risk. At the higher speed impacts, the effectiveness was less. For example, the mean maximum headform accelerations for all cricket helmets at each speed were: 67, 160, 316, and 438 g for 19, 27, 36, and 45 m/s ball speeds respectively. Drop tests on to a hemispherical anvil produced the highest accelerations. The variation in performance increased as the magnitude of the impact energy increased, in both types of testing. The test method used for baseball helmets in which the projectile is fired at the helmet may be superior to helmet drop tests. Cricket helmet performance is satisfactory for low speed impacts, but not for impacts at higher, more realistic, speeds. Baseball and ice hockey helmets offer slightly better relative and absolute performance at the 27 m/s ball and puck impacts.

Methods Used in Economic Evaluations of Chronic Kidney Disease Testing — A Systematic Review

PubMed Central

Sutton, Andrew J.; Breheny, Katie; Deeks, Jon; Khunti, Kamlesh; Sharpe, Claire; Ottridge, Ryan S.; Stevens, Paul E.; Cockwell, Paul; Kalra, Philp A.; Lamb, Edmund J.

2015-01-01

Background The prevalence of chronic kidney disease (CKD) is high in general populations around the world. Targeted testing and screening for CKD are often conducted to help identify individuals that may benefit from treatment to ameliorate or prevent their disease progression. Aims This systematic review examines the methods used in economic evaluations of testing and screening in CKD, with a particular focus on whether test accuracy has been considered, and how analysis has incorporated issues that may be important to the patient, such as the impact of testing on quality of life and the costs they incur. Methods Articles that described model-based economic evaluations of patient testing interventions focused on CKD were identified through the searching of electronic databases and the hand searching of the bibliographies of the included studies. Results The initial electronic searches identified 2,671 papers of which 21 were included in the final review. Eighteen studies focused on proteinuria, three evaluated glomerular filtration rate testing and one included both tests. The full impact of inaccurate test results was frequently not considered in economic evaluations in this setting as a societal perspective was rarely adopted. The impact of false positive tests on patients in terms of the costs incurred in re-attending for repeat testing, and the anxiety associated with a positive test was almost always overlooked. In one study where the impact of a false positive test on patient quality of life was examined in sensitivity analysis, it had a significant impact on the conclusions drawn from the model. Conclusion Future economic evaluations of kidney function testing should examine testing and monitoring pathways from the perspective of patients, to ensure that issues that are important to patients, such as the possibility of inaccurate test results, are properly considered in the analysis. PMID:26465773

49 CFR Appendix A to Part 223 - Certification of Glazing Materials

Code of Federal Regulations, 2010 CFR

2010-10-01

...-ups, test measuring devices, and test procedures were performed by qualified personnel using... following tests: (i) Ballistic Impact in which a standard 22 caliber long rifle lead bullet of 40 grains in... Impact in which a standard 22 caliber long rifle lead bullet of 40 grains in weight impacts at a minimum...

16 CFR Figure 1 to Subpart A of... - Glass Impact Test Structure

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Glass Impact Test Structure 1 Figure 1 to Subpart A of Part 1201 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... 1 to Subpart A of Part 1201—Glass Impact Test Structure EC03OC91.004 ...

16 CFR Figure 1 to Subpart A of... - Glass Impact Test Structure

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Glass Impact Test Structure 1 Figure 1 to Subpart A of Part 1201 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... 1 to Subpart A of Part 1201—Glass Impact Test Structure EC03OC91.004 ...

Two-car impact test of crash energy management passenger rail cars : analysis of occupant protection measurements

DOT National Transportation Integrated Search

2004-11-13

As a part of ongoing passenger rail equipment safety research, a full-scale impact test of two cars with energy absorbing end structures was carried out on February 26, 2004. In this test, two coupled cars impacted a rigid barrier at 29 mph. Similar ...

16 CFR Figure 9 to Part 1203 - Impact Test Apparatus

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Impact Test Apparatus 9 Figure 9 to Part 1203 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR BICYCLE HELMETS Pt. 1203, Fig. 9 Figure 9 to Part 1203—Impact Test Apparatus ER10MR98...

16 CFR Figure 9 to Part 1203 - Impact Test Apparatus

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Impact Test Apparatus 9 Figure 9 to Part 1203 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR BICYCLE HELMETS Pt. 1203, Fig. 9 Figure 9 to Part 1203—Impact Test Apparatus ER10MR98...

Impact Testing of Composites for Aircraft Engine Fan Cases

NASA Technical Reports Server (NTRS)

Roberts, Gary D.; Revilock, Duane M.; Binienda, Wieslaw K.; Nie, Walter Z.; Mackenzie, S. Ben; Todd, Kevin B.

2001-01-01

Before composite materials can be considered for use in the fan case of a commercial jet engine, the performance of a composite structure under blade-out loads needs to be demonstrated. The objective of this program is to develop an efficient test and analysis method for evaluating potential composite case concepts. Ballistic impact tests were performed on laminated glass/epoxy composites in order to identify potential failure modes and to provide data for analysis. Flat 7x7 in. panels were impacted with cylindrical titanium projectiles, and 15 in. diameter half-rings were impacted with wedge-shaped titanium projectiles. Composite failure involved local fiber fracture as well as tearing and delamination on a larger scale. A 36 in. diameter full-ring subcomponent was proposed for larger scale testing. Explicit, transient, finite element analyses were used to evaluate impact dynamics and subsequent global deformation for the proposed full-ring subcomponent test. Analyses on half-ring and quarter ring configurations indicated that less expensive smaller scale tests could be used to screen potential composite concepts when evaluation of local impact damage is the primary concern.

Ballistic Impact Testing of Aluminum 2024 and Titanium 6Al-4V for Material Model Development

NASA Technical Reports Server (NTRS)

Pereira, J. Michael; Revilock, Duane M.; Ruggeri, Charles R.; Emmerling, William C.; Altobelli, Donald J.

2012-01-01

An experimental program is underway to develop a consistent set of material property and impact test data, and failure analysis, for a variety of materials that can be used to develop improved impact failure and deformation models. Unique features of this set of data are that all material property information and impact test results are obtained using identical materials, the test methods and procedures are extensively documented and all of the raw data is available. This report describes ballistic impact testing which has been conducted on aluminum (Al) 2024 and titanium (Ti) 6Al-4vanadium (V) sheet and plate samples of different thicknesses and with different types of projectiles, one a regular cylinder and one with a more complex geometry incorporating features representative of a jet engine fan blade.

System-Integrated Finite Element Analysis of a Full-Scale Helicopter Crash Test with Deployable Energy Absorbers

NASA Technical Reports Server (NTRS)

Annett, Martin S.; Polanco, Michael A.

2010-01-01

A full-scale crash test of an MD-500 helicopter was conducted in December 2009 at NASA Langley's Landing and Impact Research facility (LandIR). The MD-500 helicopter was fitted with a composite honeycomb Deployable Energy Absorber (DEA) and tested under vertical and horizontal impact velocities of 26-ft/sec and 40-ft/sec, respectively. The objectives of the test were to evaluate the performance of the DEA concept under realistic crash conditions and to generate test data for validation of a system integrated finite element model. In preparation for the full-scale crash test, a series of sub-scale and MD-500 mass simulator tests was conducted to evaluate the impact performances of various components, including a new crush tube and the DEA blocks. Parameters defined within the system integrated finite element model were determined from these tests. The objective of this paper is to summarize the finite element models developed and analyses performed, beginning with pre-test predictions and continuing through post-test validation.

LS-DYNA Analysis of a Full-Scale Helicopter Crash Test

NASA Technical Reports Server (NTRS)

Annett, Martin S.

2010-01-01

A full-scale crash test of an MD-500 helicopter was conducted in December 2009 at NASA Langley's Landing and Impact Research facility (LandIR). The MD-500 helicopter was fitted with a composite honeycomb Deployable Energy Absorber (DEA) and tested under vertical and horizontal impact velocities of 26 ft/sec and 40 ft/sec, respectively. The objectives of the test were to evaluate the performance of the DEA concept under realistic crash conditions and to generate test data for validation of a system integrated LS-DYNA finite element model. In preparation for the full-scale crash test, a series of sub-scale and MD-500 mass simulator tests was conducted to evaluate the impact performances of various components, including a new crush tube and the DEA blocks. Parameters defined within the system integrated finite element model were determined from these tests. The objective of this paper is to summarize the finite element models developed and analyses performed, beginning with pre-test and continuing through post test validation.

Some Correlations between Plate Shatter and Fracture Toughness.

DTIC Science & Technology

1987-02-01

temperatures. In this manner, any test for plate cracking should be akin to a Charpy test, where a series of notched test bars are broken over a...cracking under ballistic impact. The PSTT test is analogous to the transition temperature in a Charpy impact test, or to the nil ductility transition (NDT...210 C to -730 C. Standard Charpy specimens were machined from the plates and subsequently precracked in fatigue to about 2.5 mm and dynamically tested

A Study of the "toss Factor" in the Impact Testing of Cermets by the Izod Pendulum Test

NASA Technical Reports Server (NTRS)

Probst, H B; Mchenry, Howard T

1957-01-01

The test method presented shows that the "toss energy" contributed by the apparatus for brittle materials is negligible. The total toss energy is considered to consist of two components. (a) recovered stored elastic energy and (b) kinetic energy contributed directly by the apparatus. The results were verified by high-speed motion pictures of the test in operation. From these photographs, velocities of tossed specimens were obtained and toss energy computed. In addition, impact energies of some titanium carbide base cermets and high-temperature alloys, as measured by the low-capacity Izod pendulum test, compare well with impact energies measured by the NACA drop test.

Quiet Clean Short-haul Experimental Engine (QCSEE) under-the-wing engine composite fan blade: Preliminary design test report

NASA Technical Reports Server (NTRS)

1975-01-01

Results of tests conducted on preliminary design polymeric-composite fan blade for the under the wing (UTW) OCSEE engine are presented. During this phase of the program a total of 17preliminary OCSEE UTW composite fan blades were manufactured for various component tests including frequency characteristics, strain distribution, bench fatigue, dovetail pull, whirligig overspeed and whirligig impact. All tests were successfully completed with the exception of whirligig impact tests. Improvements in local impact capability are being evaluated for the OCSEE blade under other NASA and related programs.

Structural impact and crashworthiness. Volume 2

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

Morton, J.

1984-01-01

These papers here were given at a conference on materials testing. The topics covered are mathematical modelling of materials, impact tests on pipes, and drop tests on scale models of lead shielded containers for radioactive materials.

Dynamic Fracture of Concrete. Part 1

DTIC Science & Technology

1990-02-14

unnotched) by Mindess and the Charpy type impact tests by Shah. In both cases, dynamic finite element modeling with the adjusted constitutive equavm for the...Mindess and the Charpy type impact tests by Shah. In both cases, dynamic finite element modeling with the adjusted constitutive equations for the...Modeling Shah’s Charpy Impact Tests ................ 190 Figure 7.20 Specimen Configuration and Finite Element Model for Concrete and Mortar Beam Impact

46 CFR 54.05-17 - Weld toughness test acceptance criteria.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Weld toughness test acceptance criteria. 54.05-17 Section 54.05-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING... impact tests the energy absorbed in both the weld metal and heat affected zone impact tests in weld...

46 CFR 54.05-17 - Weld toughness test acceptance criteria.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Weld toughness test acceptance criteria. 54.05-17 Section 54.05-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING... impact tests the energy absorbed in both the weld metal and heat affected zone impact tests in weld...

46 CFR 54.05-17 - Weld toughness test acceptance criteria.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Weld toughness test acceptance criteria. 54.05-17 Section 54.05-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING... impact tests the energy absorbed in both the weld metal and heat affected zone impact tests in weld...

46 CFR 54.05-17 - Weld toughness test acceptance criteria.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Weld toughness test acceptance criteria. 54.05-17 Section 54.05-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING... impact tests the energy absorbed in both the weld metal and heat affected zone impact tests in weld...

46 CFR 54.05-17 - Weld toughness test acceptance criteria.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Weld toughness test acceptance criteria. 54.05-17 Section 54.05-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING... impact tests the energy absorbed in both the weld metal and heat affected zone impact tests in weld...

Determining the Overall Impact of Interruptions during Online Testing

ERIC Educational Resources Information Center

Sinharay, Sandip; Wan, Ping; Whitaker, Mike; Kim, Dong-In; Zhang, Litong; Choi, Seung W.

2014-01-01

With an increase in the number of online tests, interruptions during testing due to unexpected technical issues seem unavoidable. For example, interruptions occurred during several recent state tests. When interruptions occur, it is important to determine the extent of their impact on the examinees' scores. There is a lack of research on this…

Held Back: The Impact of Curricular and Pedagogical Factors on Tested Achievement in High School Mathematics

ERIC Educational Resources Information Center

Agvanian, Zara

2013-01-01

This study examined the impact of curricular factors and teaching practices on students' tested achievement in mathematics, explored the best predictors of the tested achievement, and examined differences in the tested achievement among student subgroups. The study utilized qualitative and quantitative methods and triangulated findings from…

Light airplane crash tests at impact velocities of 13 and 27 m/sec

NASA Technical Reports Server (NTRS)

Alfaro-Bou, E.; Vaughan, V. L., Jr.

1977-01-01

Two similar general aviation airplanes were crash tested at the Langley impact dynamics research facility at velocities of 13 and 27 m/sec. Other flight parameters were held constant. The facility, instrumentation, tests specimens, and test method are briefly described. Structural damage and accelerometer data are discussed.

Low temperature mechanical properties, fractographic and metallographic evaluation of several alloy steels

NASA Technical Reports Server (NTRS)

Montano, J. W.

1973-01-01

The mechanical properties are presented of alloy steels, 4130, 4140, 4340, 6150, and 8740. Test specimens were manufactured from approximately 1.00 inch (2.54 cm) diameter bar stock which had been heat treated to two different hardness levels. The following mechanical tests were performed at temperatures of 80 F (+26.7 C), 0 F (-17.8 C), -100 F (-73 C), and -200 F (-129 C): (1) tensile test (Ultimate, yield, modulus, elongation, and reduction of area), (2) notched tensile test, (3) charpy V-notched impact test (impact energy), and (4) double shear strength test (ultimate and yield). The test data indicate excellent tensile strength, notched/unnotched tensile ratios, ductility, impact, and shear properties at all test temperatures, except at -200 F (-129 C) where the impact strength of the higher strength group of alloy steels, 4130 (Rc-37) and 4140 (Rc-44) decreased to approximately 9 ft. lbs. (12 joules) and 6 ft. lbs. (8 joules), respectively. Chemical, metallographic, and fractographic analyses were also performed to evaluate microstructure, microhardness and the effect of decrease in temperature on the ductile to brittle failure transition.

Apparatus for Hot Impact Testing of Material Specimens

NASA Technical Reports Server (NTRS)

Pawlik, Ralph J.; Choi, Sung R.

2006-01-01

An apparatus for positioning and holding material specimens is a major subsystem of a system for impact testing of the specimens at temperatures up to 1,500 C. This apparatus and the rest of the system are designed especially for hot impact testing of advanced ceramics, composites, and coating materials. The apparatus includes a retaining fixture on a rotating stage on a vertically movable cross support driven by a linear actuator. These components are located below a furnace wherein the hot impact tests are performed (see Figure 1). In preparation for a test, a specimen is mounted on the retaining fixture, then the cross support is moved upward to raise the specimen, through an opening in the bottom of the furnace, to the test position inside the furnace. On one side of the furnace there is another, relatively small opening on a direct line to the specimen. Once the specimen has become heated to the test temperature, the test is performed by using an instrumented external pressurized-gas-driven gun to shoot a projectile through the side opening at the specimen.

Degradation Factor Approach for Impacted Composite Structural Assessment: MSFC Center Director's Discretionary Fund Final Report, Project No. 96-17

NASA Technical Reports Server (NTRS)

Ortega, R.; Price, J. M.; Fox, D.

2000-01-01

This technical memorandum documents the results of the research to develop a concept for assessing the structural integrity of impacted composite structures using the strength degradation factor in conjunction with available finite element tools. For this purpose, a literature search was conducted, a plan for conducting impact testing on two laminates was developed, and a finite element model of the impact process was created. Specimens for the impact testing were fabricated to support the impact testing plan.

Hypervelocity Impact (HVI). Volume 7; WLE High Fidelity Specimen RCC16R

NASA Technical Reports Server (NTRS)

Gorman, Michael R.; Ziola, Steven M.

2007-01-01

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Target RCC16R was to study hypervelocity impacts through the reinforced carbon-carbon (RCC) panels of the Wing Leading Edge. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Full-Scale Passive Earth Entry Vehicle Landing Tests: Methods and Measurements

NASA Technical Reports Server (NTRS)

Littell, Justin D.; Kellas, Sotiris

2018-01-01

During the summer of 2016, a series of drop tests were conducted on two passive earth entry vehicle (EEV) test articles at the Utah Test and Training Range (UTTR). The tests were conducted to evaluate the structural integrity of a realistic EEV vehicle under anticipated landing loads. The test vehicles were lifted to an altitude of approximately 400m via a helicopter and released via release hook into a predesignated 61 m landing zone. Onboard accelerometers were capable of measuring vehicle free flight and impact loads. High-speed cameras on the ground tracked the free-falling vehicles and data was used to calculate critical impact parameters during the final seconds of flight. Additional sets of high definition and ultra-high definition cameras were able to supplement the high-speed data by capturing the release and free flight of the test articles. Three tests were successfully completed and showed that the passive vehicle design was able to withstand the impact loads from nominal and off-nominal impacts at landing velocities of approximately 29 m/s. Two out of three test resulted in off-nominal impacts due to a combination of high winds at altitude and the method used to suspend the vehicle from the helicopter. Both the video and acceleration data captured is examined and discussed. Finally, recommendations for improved release and instrumentation methods are presented.

Development of testing machine for tunnel inspection using multi-rotor UAV

NASA Astrophysics Data System (ADS)

Iwamoto, Tatsuya; Enaka, Tomoya; Tada, Keijirou

2017-05-01

Many concrete structures are deteriorating to dangerous levels throughout Japan. These concrete structures need to be inspected regularly to be sure that they are safe enough to be used. The inspection method for these concrete structures is typically the impact acoustic method. In the impact acoustic method, the worker taps the surface of the concrete with a hammer. Thus, it is necessary to set up scaffolding to access tunnel walls for inspection. Alternatively, aerial work platforms can be used. However, setting up scaffolding and aerial work platforms is not economical with regard to time or money. Therefore, we developed a testing machine using a multirotor UAV for tunnel inspection. This test machine flies by a plurality of rotors, and it is pushed along a concrete wall and moved by using rubber crawlers. The impact acoustic method is used in this testing machine. This testing machine has a hammer to make an impact, and a microphone to acquire the impact sound. The impact sound is converted into an electrical signal and is wirelessly transmitted to the computer. At the same time, the position of the testing machine is measured by image processing using a camera. The weight and dimensions of the testing machine are approximately 1.25 kg and 500 mm by 500 mm by 250 mm, respectively.

Conventional fuel tank blunt impact tests : test and analysis results

DOT National Transportation Integrated Search

2014-04-02

The Federal Railroad Administrations Office of Research : and Development is conducting research into fuel tank : crashworthiness. A series of impact tests are planned to : measure fuel tank deformation under two types of dynamic : loading conditi...

Test requirements of locomotive fuel tank blunt impact tests

DOT National Transportation Integrated Search

2013-10-15

The Federal Railroad Administrations Office of Research : and Development is conducting research into passenger : locomotive fuel tank crashworthiness. A series of impact tests : are planned to measure fuel tank deformation under two types : of dy...

Evaluation of a Singular Value Decomposition Approach for Impact Dynamic Data Correlation

NASA Technical Reports Server (NTRS)

Horta, Lucas G.; Lyle, Karen H.; Lessard, Wendy B.

2003-01-01

Impact dynamic tests are used in the automobile and aircraft industries to assess survivability of occupants during crash, to assert adequacy of the design, and to gain federal certification. Although there is no substitute for experimental tests, analytical models are often developed and used to study alternate test conditions, to conduct trade-off studies, and to improve designs. To validate results from analytical predictions, test and analysis results must be compared to determine the model adequacy. The mathematical approach evaluated in this paper decomposes observed time responses into dominant deformation shapes and their corresponding contribution to the measured response. To correlate results, orthogonality of test and analysis shapes is used as a criterion. Data from an impact test of a composite fuselage is used and compared to finite element predictions. In this example, the impact response was decomposed into multiple shapes but only two dominant shapes explained over 85% of the measured response

Burst Pressure Failure of Titanium Tanks Damaged by Secondary Plumes from Hypervelocity Impacts on Aluminum Shields

NASA Technical Reports Server (NTRS)

Nahra, Henry; Ghosn, Louis; Christiansen, Eric; Davis, B. Alan; Keddy, Chris; Rodriquez, Karen; Miller, Joshua; Bohl, William

2011-01-01

Metallic pressure tanks used in space missions are inherently vulnerable to hypervelocity impacts from micrometeoroids and orbital debris; thereby knowledge of impact damage and its effect on the tank integrity is crucial to a spacecraft risk assessment. This paper describes tests that have been performed to assess the effects of hypervelocity impact (HVI) damage on Titanium alloy (Ti-6Al-4V) pressure vessels burst pressure and characteristics. The tests consisted of a pair of HVI impact tests on water-filled Ti-6Al-4V tanks (water being used as a surrogate to the actual propellant) and subsequent burst tests as well as a burst test on an undamaged control tank. The tanks were placed behind Aluminum (Al) shields and then each was impacted with a 7 km/s projectile. The resulting impact debris plumes partially penetrated the Ti-6Al-4V tank surfaces resulting in a distribution of craters. During the burst tests, the tank that failed at a lower burst pressure did appear to have the failure initiating at a crater site with observed spall cracks. A fracture mechanics analysis showed that the tanks failure at the impact location may have been due to a spall crack that formed upon impact of a fragmentation on the Titanium surface. This result was corroborated with a finite element analysis from calculated Von-Mises and hoop stresses.

Program for impact testing of spar-shell fan blades, test report

NASA Technical Reports Server (NTRS)

Ravenhall, R.; Salemme, C. T.

1978-01-01

Six filament-wound, composite spar-shell fan blades were impact tested in a whirligig relative to foreign object damage resulting from ingestion of birds into the fan blades of a QCSEE-type engine. Four of the blades were tested by injecting a simulated two pound bird into the path of the rotating blade and two were tested by injecting a starling into the path of the blade.

Pressure scaled water impact test of a 12.5 inch diameter model of the Space Shuttle solid rocket booster

NASA Technical Reports Server (NTRS)

1982-01-01

A total of 59 tail first drops were made. Model entry conditions simulated full scale vertical velocities of approximately 75 to 110 ft/sec with horizontal velocities up to 45 ft/sec and impact angles to + or - 10 deg. These tests were conducted at scaled atmospheric pressures (1.26 psia or 65 mm.Hg). The model, test program, test facility, test equipment, instrumentation system, data reduction procedures, and test results are described.

Pretest Plan for a Quarter Scale AFT Segment of the SRB Filament Wound Case in the NSWC Hydroballistics Facility. [space shuttle boosters

NASA Technical Reports Server (NTRS)

Adoue, J. A.

1984-01-01

In support of preflight design loads definition, preliminary water impact scale model are being conducted of space shuttle rocket boosters. The model to be used as well as the instrumentation, test facilities, and test procedures are described for water impact tests being conducted at test conditions to simulate full-scale initial impact at vertical velocities from 65 to 85 ft/sec. zero horizontal velocity, and angles of 0,5, and 10 degrees.

The influence of validity criteria on Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test-retest reliability among high school athletes.

PubMed

Brett, Benjamin L; Solomon, Gary S

2017-04-01

Research findings to date on the stability of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) Composite scores have been inconsistent, requiring further investigation. The use of test validity criteria across these studies also has been inconsistent. Using multiple measures of stability, we examined test-retest reliability of repeated ImPACT baseline assessments in high school athletes across various validity criteria reported in previous studies. A total of 1146 high school athletes completed baseline cognitive testing using the online ImPACT test battery at two time periods of approximately two-year intervals. No participant sustained a concussion between assessments. Five forms of validity criteria used in previous test-retest studies were applied to the data, and differences in reliability were compared. Intraclass correlation coefficients (ICCs) ranged in composite scores from .47 (95% confidence interval, CI [.38, .54]) to .83 (95% CI [.81, .85]) and showed little change across a two-year interval for all five sets of validity criteria. Regression based methods (RBMs) examining the test-retest stability demonstrated a lack of significant change in composite scores across the two-year interval for all forms of validity criteria, with no cases falling outside the expected range of 90% confidence intervals. The application of more stringent validity criteria does not alter test-retest reliability, nor does it account for some of the variation observed across previously performed studies. As such, use of the ImPACT manual validity criteria should be utilized in the determination of test validity and in the individualized approach to concussion management. Potential future efforts to improve test-retest reliability are discussed.

Hypervelocity Impact (HVI). Volume 1; General Introduction

NASA Technical Reports Server (NTRS)

Gorman, Michael R.; Ziola, Steven M.

2007-01-01

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. This volume contains an executive summary, overview of the method, brief descriptions of all targets, and highlights of results and conclusions.

Nonlinear elastic behavior of sub-critically damaged body armor panel

NASA Astrophysics Data System (ADS)

Fisher, Jason T.; Chimenti, D. E.

2012-05-01

A simple go/no-go test for body armor panels using pressure-sensitive, dye-indicator film (PSF) has been shown to be statistically effective in revealing subcritical damage to body armor panels. Previous measurements have shown that static indicator levels are accurately reproduced in dynamic loading events. Further impact tests on armor worn by a human resuscitation dummy using instrumented masses with an attached accelerometer and embedded force transducer have been performed and analyzed. New impact tests have shown a reliable correlation between PSF indication (as digitized images) and impact force for a wide range of impactor energies and masses. Numerical evaluation of digital PSF images is presented and correlated with impact parameters. Relationships between impactor mass and energy, and corresponding measured force are shown. We will also report on comparisons between ballistic testing performed on panels damaged under various impact conditions and tests performed on undamaged panels.

Taylor Impact Tests and Simulations on PBX 9501

NASA Astrophysics Data System (ADS)

Clements, Brad; Thompson, Darla G.; Luscher, D. J.; Deluca, Racci

2011-06-01

Taylor impact tests have been conducted previously on plastic bonded explosives (PBXs) to characterize the stress state of these materials as they impact smooth and flat steel anvil surfaces at speeds of ~100m/s (i.e. Christopher, et al, 11th Detonation Symposium). In 2003, C. Liu and R. Ellis (unpublished, Los Alamos National Laboratory) performed Taylor tests on PBX 9501 up to speeds of 115 m/s, capturing impact images. In the work presented here, we have extended these tests to velocities of 200 m/s using a composite-lined gun barrel and no specimen sabot. Specimen images are used to validate the thermo-mechanical constitutive model ViscoSCRAM. ViscoSCRAM has been parameterized for PBX 9501 in uniaxial stress configurations. Simulating Taylor impact experiments tests the model in situations undergoing extreme damage. In addition, experimental variations to specimen confinement and friction are introduced in an attempt to establish ignition thresholds in this velocity regime.

Design, Fabrication and Test of Multi-Fiber Laminates

NASA Technical Reports Server (NTRS)

Pike, R. A.; Novak, R. C.

1975-01-01

Unidirectional and angleply multifiber laminates were tested for improved impact strength and other mechanical properties. The effects of several variables on the mechanical properties of epoxy matrix materials were described. These include fiber type (HMS and AS graphites, glass, and Kevlar 49), ratio of primary to hybridizing fiber and hybrid configuration. It is demonstrated that AS graphite/S glass in an intraply configuration results in the best combination of static and Charpy impact properties as well as superior ballistic impact resistance. Pendulum impact tests which were conducted on thin specimens are shown to produce different ranking of materials than tests conducted on standard thickness Charpy specimens. It is shown that the thin specimen results are in better agreement with the ballistic impact data. Additional static test data are reported as a function of temperature for the seven best hybrid configurations having epoxy, polyimide (PMR-15) and polyphenylquinoxaline resins as the matrix.

Oxygen Compatibility Testing of Composite Materials

NASA Technical Reports Server (NTRS)

Engel, Carl D.; Watkins, Casey N.

2006-01-01

Composite materials offer significant weight-saving potential for aerospace applications in propellant and oxidizer tanks. This application for oxygen tanks presents the challenge of being oxygen compatible in addition to complying with the other required material characteristics. This effort reports on the testing procedures and data obtained in examining and selecting potential composite materials for oxygen tank usage. Impact testing of composites has shown that most of these materials initiate a combustion event when impacted at 72 ft-lbf in the presence of liquid oxygen, though testing has also shown substantial variability in reaction sensitivities to impact. Data for screening of 14 potential composites using the Bruceton method is given herein and shows that the 50-percent reaction frequencies range from 17 to 67 ft-lbf. The pressure and temperature rises for several composite materials were recorded to compare the energy releases as functions of the combustion reactions with their respective reaction probabilities. The test data presented are primarily for a test pressure of 300 psia in liquid oxygen. The impact screening process is compared with oxygen index and autogenous ignition test data for both the composite and the basic resin. The usefulness of these supplemental tests in helping select the most oxygen compatible materials is explored. The propensity for mechanical impact ignition of the composite compared with the resin alone is also examined. Since an ignition-free composite material at the peak impact energy of 72 ft-lbf has not been identified, composite reactivity must be characterized over the impact energy level and operating pressure ranges to provide data for hazard analyses in selecting the best potential material for liquid tank usage.

Test Report for MSFC Test No. 83-2: Pressure scaled water impact test of a 12.5 inch diameter model of the Space Shuttle solid rocket booster filament wound case and external TVC PCD

NASA Technical Reports Server (NTRS)

1983-01-01

Water impact tests using a 12.5 inch diameter model representing a 8.56 percent scale of the Space Shuttle Solid Rocket Booster configuration were conducted. The two primary objectives of this SRB scale model water impact test program were: 1. Obtain cavity collapse applied pressure distributions for the 8.56 percent rigid body scale model FWC pressure magnitudes as a function of full-scale initial impact conditions at vertical velocities from 65 to 85 ft/sec, horizontal velocities from 0 to 45 ft/sec, and angles from -10 to +10 degrees. 2. Obtain rigid body applied pressures on the TVC pod and aft skirt internal stiffener rings at initial impact and cavity collapse loading events. In addition, nozzle loads were measured. Full scale vertical velocities of 65 to 85 ft/sec, horizontal velocities of 0 to 45 ft/sec, and impact angles from -10 to +10 degrees simulated.

Full-field Deformation Measurement Techniques for a Rotating Composite Shaft

NASA Technical Reports Server (NTRS)

Kohlman, Lee W.; Ruggeri, Charles R.; Martin, Richard E.; Roberts, Gary D.; Handschuh, Robert F.; Roth, Don J.

2012-01-01

Test methods were developed to view global and local deformation in a composite tube during a test in which the tube is rotating at speeds and torques relevant to rotorcraft shafts. Digital image correlation (DIC) was used to provide quantitative displacement measurements during the tests. High speed cameras were used for the DIC measurements in order to capture images at sufficient frame rates and with sufficient resolution while the tube was rotating at speeds up to 5,000 rpm. Surface displacement data was resolved into cylindrical coordinates in order to measure rigid body rotation and global deformation of the tube. Tests were performed on both undamaged and impact damaged tubes in order to evaluate the capability to detect local deformation near an impact damaged site. Measurement of radial displacement clearly indicated a local buckling deformation near the impacted site in both dynamic and static tests. X-ray computed tomography (CT) was used to investigate variations in fiber architecture within the composite tube and to detect impact damage. No growth in the impact damage area was observed by DIC during dynamic testing or by x-ray CT in post test inspection of the composite tube.

Single passenger rail car impact test. Volume III, Test procedures, instrumentation and data.

DOT National Transportation Integrated Search

2000-01-12

A full-scale impact test was performed November 16, 1999, at the Federal Railroad Administrations Transportation : Technology Center, Pueblo, Colorado, by Transportation Technology Center, Inc., a subsidiary of the Association of : American Railro...

30 CFR 7.46 - Impact test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.46 Impact test. (a) Test... at 122 °F (50 °C) for a period of 48 hours. (2) Mount the covers on a battery box of the same design with which the covers are to be approved, including any support blocks, with the battery cells...

Assessing Individual-Level Impact of Interruptions during Online Testing

ERIC Educational Resources Information Center

Sinharay, Sandip; Wan, Ping; Choi, Seung W.; Kim, Dong-In

2015-01-01

With an increase in the number of online tests, the number of interruptions during testing due to unexpected technical issues seems to be on the rise. For example, interruptions occurred during several recent state tests. When interruptions occur, it is important to determine the extent of their impact on the examinees' scores. Researchers such as…

Methods for data reduction and loads analysis of Space Shuttle Solid Rocket Booster model water impact tests

NASA Technical Reports Server (NTRS)

1976-01-01

The methodology used to predict full scale space shuttle solid rocket booster (SRB) water impact loads from scale model test data is described. Tests conducted included 12.5 inch and 120 inch diameter models of the SRB. Geometry and mass characteristics of the models were varied in each test series to reflect the current SRB baseline configuration. Nose first and tail first water entry modes were investigated with full-scale initial impact vertical velocities of 40 to 120 ft/sec, horizontal velocities of 0 to 60 ft/sec., and off-vertical angles of 0 to plus or minus 30 degrees. The test program included a series of tests with scaled atmospheric pressure.

Cognitive skills, student achievement tests, and schools.

PubMed

Finn, Amy S; Kraft, Matthew A; West, Martin R; Leonard, Julia A; Bish, Crystal E; Martin, Rebecca E; Sheridan, Margaret A; Gabrieli, Christopher F O; Gabrieli, John D E

2014-03-01

Cognitive skills predict academic performance, so schools that improve academic performance might also improve cognitive skills. To investigate the impact schools have on both academic performance and cognitive skills, we related standardized achievement-test scores to measures of cognitive skills in a large sample (N = 1,367) of eighth-grade students attending traditional, exam, and charter public schools. Test scores and gains in test scores over time correlated with measures of cognitive skills. Despite wide variation in test scores across schools, differences in cognitive skills across schools were negligible after we controlled for fourth-grade test scores. Random offers of enrollment to oversubscribed charter schools resulted in positive impacts of such school attendance on math achievement but had no impact on cognitive skills. These findings suggest that schools that improve standardized achievement-test scores do so primarily through channels other than improving cognitive skills.

Orbital Debris Impact Damage to Reusable Launch Vehicles

NASA Technical Reports Server (NTRS)

Robinson, Jennifer H.

1998-01-01

In an effort by the National Aeronautics and Space Administration (NASA), hypervelocity impact tests were performed on thermal protection systems (TPS) applied on the external surfaces of reusable launch vehicles (RLV) to determine the potential damage from orbital debris impacts. Three TPS types were tested, bonded to composite structures representing RLV fuel tank walls. The three heat shield materials tested were Alumina-Enhanced Thermal Barrier-12 (AETB-12), Flexible Reusable Surface Insulation (FRSI), and Advanced Flexible Reusable Surface Insulation (AFRSI). Using this test data, predictor equations were developed for the entry hole diameters in the three TPS materials, with correlation coefficients ranging from 0.69 to 0.86. Possible methods are proposed for approximating damage occurring at expected orbital impact velocities higher than tested, with references to other published work.

Final Environmental Assessment for Conventional Strike Missile Demonstration

DTIC Science & Technology

2010-08-11

impacts of conducting a single demonstration flight test of the Conventional Strike Missile (CSM). The CSM Demonstration flight test vehicle would...Vehicle would glide at hypersonic velocities in the upper atmosphere, prior to a land or ocean impact at the US Army Kwajalein Atoll/Reagan Test Site...SIGNIFICANT IMPACT ENVIRONMENTAL ASSESSMENT FOR CONVENTIONAL STRIKE MISSILE DEMONSTRATION AGENCY: United States Air Force (USAF) BACKGROUND

INTER LABORATORY COMBAT HELMET BLUNT IMPACT TEST METHOD COMPARISON

DTIC Science & Technology

2018-03-26

HELMET BLUNT IMPACT TEST METHOD COMPARISON by Tony J. Kayhart Charles A. Hewitt and Jonathan Cyganik March 2018 Final...Report March 2016 – August 2017 Approved for public release; distribution is unlimited U.S. Army Natick Soldier Research ...INTER-LABORATORY COMBAT HELMET BLUNT IMPACT TEST METHOD COMPARISON 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

46 CFR 54.05-20 - Impact test properties for service of 0 °F and below.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... See § 54.05-5(c) for retest requirements. Table 54.05-20(a)—Charpy v-notch impact requirements Size of... permitted. (b) Transversely oriented Charpy V-notch impact specimens of ASTM A 203 (incorporated by... correlation with drop-weight tests, Charpy V-notch tests may be specially considered by the Commandant in lieu...

Experimental Investigation of Fibre Reinforced Composite Materials Under Impact Load

NASA Astrophysics Data System (ADS)

Koppula, Sravani; Kaviti, Ajay kumar; Namala, Kiran kumar

2018-03-01

Composite materials are extensively used in various engineering applications. They have very high flexibility design which allows prescribe tailoring of material properties by lamination of composite fibres with reinforcement of resin to it. Complex failure condition prevail in the composite materials under the action of impact loads, major modes of failure in composite may include matrix cracking, fibre matrix, fibre breakage, de-bonding or de- lamination between composite plies. This paper describes the mechanical properties of glass fibre reinforced composite material under impact loading conditions through experimental setup. Experimental tests are performed according to ASTM standards using impact testing machines like Charpy test, computerized universal testing machine.

International Space Station (ISS) Soyuz Vehicle Descent Module Evaluation of Thermal Protection System (TPS) Penetration Characteristics

NASA Technical Reports Server (NTRS)

Davis, Bruce A.; Christiansen, Eric L.; Lear, Dana M.; Prior, Tom

2013-01-01

The descent module (DM) of the ISS Soyuz vehicle is covered by thermal protection system (TPS) materials that provide protection from heating conditions experienced during reentry. Damage and penetration of these materials by micrometeoroid and orbital debris (MMOD) impacts could result in loss of vehicle during return phases of the mission. The descent module heat shield has relatively thick TPS and is protected by the instrument-service module. The TPS materials on the conical sides of the descent module (referred to as backshell in this test plan) are exposed to more MMOD impacts and are relatively thin compared to the heat shield. This test program provides hypervelocity impact (HVI) data on materials similar in composition and density to the Soyuz TPS on the backshell of the vehicle. Data from this test program was used to update ballistic limit equations used in Soyuz TPS penetration risk assessments. The impact testing was coordinated by the NASA Johnson Space Center (JSC) Hypervelocity Impact Technology (HVIT) Group [1] in Houston, Texas. The HVI testing was conducted at the NASA-JSC White Sands Hypervelocity Impact Test Facility (WSTF) at Las Cruces, New Mexico. Figure

An overview of passenger equipment full-scale impact tests

DOT National Transportation Integrated Search

2003-10-07

As part of the Federal Railroad Administrations Equipment Safety Research Program, a series of full-scale impact tests are being conducted on rail passenger vehicles. Four types of tests are intended to define the performance of current-design equ...

An overview of passenger equipment fullscale impact tests : results to date

DOT National Transportation Integrated Search

2001-11-25

As part of the Federal Railroad Administrations Equipment Safety Research Program, a series of full-scale impact tests are being conducted on rail passenger vehicles. Three tests are intended to define the performance of current-design equipment i...

Passenger rail two-car impact test. Volume 2 : summary of occupant protection program

DOT National Transportation Integrated Search

2002-01-01

Two full-scale impact tests of rail cars fitted with seat/occupant experiments were conducted at the Federal Railroad Administrations Transportation Technology Center located in Pueblo, Colorado. The first test was conducted on November 16, 1999, ...

Hypervelocity Impact Test Results for a Metallic Thermal Protection System

NASA Technical Reports Server (NTRS)

Karr, Katherine L.; Poteet, Carl C.; Blosser, Max L.

2003-01-01

Hypervelocity impact tests have been performed on specimens representing metallic thermal protection systems (TPS) developed at NASA Langley Research Center for use on next-generation reusable launch vehicles (RLV). The majority of the specimens tested consists of a foil gauge exterior honeycomb panel, composed of either Inconel 617 or Ti-6Al-4V, backed with 2.0 in. of fibrous insulation and a final Ti-6Al-4V foil layer. Other tested specimens include titanium multi-wall sandwich coupons as well as TPS using a second honeycomb sandwich in place of the foil backing. Hypervelocity impact tests were performed at the NASA Marshall Space Flight Center Orbital Debris Simulation Facility. An improved test fixture was designed and fabricated to hold specimens firmly in place during impact. Projectile diameter, honeycomb sandwich material, honeycomb sandwich facesheet thickness, and honeycomb core cell size were examined to determine the influence of TPS configuration on the level of protection provided to the substructure (crew, cabin, fuel tank, etc.) against micrometeoroid or orbit debris impacts. Pictures and descriptions of the damage to each specimen are included.

Modeling the low-velocity impact characteristics of woven glass epoxy composite laminates using artificial neural networks

NASA Astrophysics Data System (ADS)

Mathivanan, N. Rajesh; Mouli, Chandra

2012-12-01

In this work, a new methodology based on artificial neural networks (ANN) has been developed to study the low-velocity impact characteristics of woven glass epoxy laminates of EP3 grade. To train and test the networks, multiple impact cases have been generated using statistical analysis of variance (ANOVA). Experimental tests were performed using an instrumented falling-weight impact-testing machine. Different impact velocities and impact energies on different thicknesses of laminates were considered as the input parameters of the ANN model. This model is a feed-forward back-propagation neural network. Using the input/output data of the experiments, the model was trained and tested. Further, the effects of the low-velocity impact response of the laminates at different energy levels were investigated by studying the cause-effect relationship among the influential factors using response surface methodology. The most significant parameter is determined from the other input variables through ANOVA.

Repeatability and uncertainty analyses of light gas gun test data

NASA Technical Reports Server (NTRS)

Schonberg, William P.; Cooper, David

1994-01-01

All large spacecraft are susceptible to high-speed impacts by meteoroids and pieces of orbiting space debris which can damage flight-critical systems and in turn lead to catastrophic failure. One way to obtain information on the response of a structure to a meteoroid impact or an orbital debris impact is to simulate the impact conditions of interest in the laboratory and analyze the resulting damage to a target structure. As part of the Phase B and C/D development activities for the Space Station Freedom, 950 impact tests were performed using the NASA/Marshall Space Flight Center (MSFC) light gas gun from 1985-1991. This paper presents the results of impact phenomena repeatability and data uncertainty studies performed using the information obtained from those tests. The results of these studies can be used to assess the utility of individual current and future NASA/MSFC impact test results in the design of long-duration spacecraft.

Application of impact dampers in vibration control of flexible structures

NASA Technical Reports Server (NTRS)

Akl, Fred A.; Butt, Aamir S.

1995-01-01

Impact dampers belong to the category of passive vibration devices used to attenuate the vibration of discrete and continuous systems. An impact damper generally consists of a mass which is allowed to travel freely between two defined stops. Under the right conditions, the vibration of the structure to which the impact damper is attached will cause the mass of the impact damper to strike the structure. Previous analytical and experimental research work on the effect of impact dampers in attenuating the vibration of discrete and continuous systems have demonstrated their effectiveness. It has been shown in this study that impact dampers can increase the intrinsic damping of a lightly-damped flexible structure. The test structure consists of a slender flexible beam supported by a pin-type support at one end and supported by a linear helical flexible spring at another location. Sinusoidal excitation spanning the first three natural frequencies was applied in the horizontal plane. The orientation of the excitation and the test structure in the horizontal plane minimizes the effect of gravity on the behavior of the test structure. The excitation was applied using a linear sine sweep technique. The span of the test structure, the mass of the impact damper, the distance of travel, and the location of the impact damper along the span of the test structure were varied. The damping ratio are estimated for sixty test configurations. The results show that the impact damper significantly increases the damping ratio of the test structure. Statistical analysis of the results using the method of multiple linear regression indicates that a reasonable fit has been accomplished. It is concluded that additional experimental analysis of flexible structures in microgravity environment is needed in order to achieve a better understanding of the behavior of impact damper under conditions of microgravity. Numerical solution of the behavior of flexible structures equipped with impact dampers is also needed to predict stresses and deformations under operating conditions of microgravity in space applications.

Damage Characteristics and Residual Strength of Composite Sandwich Panels Impacted with and Without Compression Loading

NASA Technical Reports Server (NTRS)

McGowan, David M.; Ambur, Damodar R.

1998-01-01

The results of an experimental study of the impact damage characteristics and residual strength of composite sandwich panels impacted with and without a compression loading are presented. Results of impact damage screening tests conducted to identify the impact-energy levels at which damage initiates and at which barely visible impact damage occurs in the impacted facesheet are discussed. Parametric effects studied in these tests include the impactor diameter, dropped-weight versus airgun-launched impactors, and the effect of the location of the impact site with respect to the panel boundaries. Residual strength results of panels tested in compression after impact are presented and compared with results of panels that are subjected to a compressive preload prior to being impacted.

Marshall Space Flight Center's Impact Testing Facility Capabilities

NASA Technical Reports Server (NTRS)

Finchum, Andy; Hubbs, Whitney; Evans, Steve

2008-01-01

Marshall Space Flight Center s (MSFC) Impact Testing Facility (ITF) serves as an important installation for space and missile related materials science research. The ITF was established and began its research in spacecraft debris shielding in the early 1960s, then played a major role in the International Space Station debris shield development. As NASA became more interested in launch debris and in-flight impact concerns, the ITF grew to include research in a variety of impact genres. Collaborative partnerships with the DoD led to a wider range of impact capabilities being relocated to MSFC as a result of the closure of Particle Impact Facilities in Santa Barbara, California. The Particle Impact Facility had a 30 year history in providing evaluations of aerospace materials and components during flights through rain, ice, and solid particle environments at subsonic through hypersonic velocities. The facility s unique capabilities were deemed a "National Asset" by the DoD. The ITF now has capabilities including environmental, ballistic, and hypervelocity impact testing utilizing an array of air, powder, and two-stage light gas guns to accommodate a variety of projectile and target types and sizes. Numerous upgrades including new instrumentation, triggering circuitry, high speed photography, and optimized sabot designs have been implemented. Other recent research has included rain drop demise characterization tests to obtain data for inclusion in on-going model development. The current and proposed ITF capabilities range from rain to micrometeoroids allowing the widest test parameter range possible for materials investigations in support of space, atmospheric, and ground environments. These test capabilities including hydrometeor, single/multi-particle, ballistic gas guns, exploding wire gun, and light gas guns combined with Smooth Particle Hydrodynamics Code (SPHC) simulations represent the widest range of impact test capabilities in the country.

The Impact of Escape Alternative Position Change in Multiple-Choice Test on the Psychometric Properties of a Test and Its Items Parameters

ERIC Educational Resources Information Center

Hamadneh, Iyad Mohammed

2015-01-01

This study aimed at investigating the impact changing of escape alternative position in multiple-choice test on the psychometric properties of a test and it's items parameters (difficulty, discrimination & guessing), and estimation of examinee ability. To achieve the study objectives, a 4-alternative multiple choice type achievement test…

Train-to-train impact test : occupant protection experiments

DOT National Transportation Integrated Search

2002-11-17

This paper describes the results of the occupant protection experiments included as part of the train-to-train impact test conducted at the Transportation Technology Center in Pueblo, Colorado on January 31, 2002. In this test, a cab car-led train, i...

An Investigation of the Impact of Guessing on Coefficient α and Reliability

PubMed Central

2014-01-01

Guessing is known to influence the test reliability of multiple-choice tests. Although there are many studies that have examined the impact of guessing, they used rather restrictive assumptions (e.g., parallel test assumptions, homogeneous inter-item correlations, homogeneous item difficulty, and homogeneous guessing levels across items) to evaluate the relation between guessing and test reliability. Based on the item response theory (IRT) framework, this study investigated the extent of the impact of guessing on reliability under more realistic conditions where item difficulty, item discrimination, and guessing levels actually vary across items with three different test lengths (TL). By accommodating multiple item characteristics simultaneously, this study also focused on examining interaction effects between guessing and other variables entered in the simulation to be more realistic. The simulation of the more realistic conditions and calculations of reliability and classical test theory (CTT) item statistics were facilitated by expressing CTT item statistics, coefficient α, and reliability in terms of IRT model parameters. In addition to the general negative impact of guessing on reliability, results showed interaction effects between TL and guessing and between guessing and test difficulty.

Impact of a Routine, Opt-Out HIV Testing Program on HIV Testing and Case Detection in North Carolina Sexually-Transmitted Disease Clinics

PubMed Central

Klein, Pamela W.; Messer, Lynne C.; Myers, Evan R.; Weber, David J.; Leone, Peter A.; Miller, William C.

2016-01-01

The impact of routine, opt-out HIV testing programs in clinical settings is inconclusive. The objective of this study was to estimate the impact of an expanded, routine HIV testing program in North Carolina sexually transmitted disease (STD) clinics on HIV testing and case detection. Adults aged 18–64 who received an HIV test in a North Carolina STD clinic July 1, 2005 through June 30, 2011 were included in this analysis, dichotomized at the date of implementation on November 1, 2007. HIV testing and case detection counts and rates were analyzed using interrupted time series analysis, and Poisson and multilevel logistic regression. Pre-intervention, 426 new HIV-infected cases were identified from 128,029 tests (0.33%), whereas 816 new HIV-infected cases were found from 274,745 tests post-intervention (0.30%). Pre-intervention, HIV testing increased by 55 tests per month (95% confidence interval [CI]: 41, 72), but only 34 tests per month (95% CI: 26, 42) post-intervention. Increases in HIV testing rates were most pronounced in females and non-Hispanic whites. A slight pre-intervention decline in case detection was mitigated by the intervention (mean difference [MD]=0.01; 95% CI: −0.02, 0.05). Increases in case detection rates were observed among females and non-Hispanic blacks. The impact of a routine HIV screening in North Carolina STD clinics was marginal, with the greatest benefit among persons not traditionally targeted for HIV testing. The use of a pre-intervention comparison period identified important temporal trends that otherwise would have been ignored. PMID:24825338

Impact Testing and Analysis of Composites for Aircraft Engine Fan Cases

NASA Technical Reports Server (NTRS)

Roberts, Gary D.; Revilock, Duane M.; Binienda, Wieslaw K.; Nie, Walter Z.; Mackenzie, S. Ben; Todd, Kevin B.

2002-01-01

The fan case in a jet engine is a heavy structure because of its size and because of the requirement that it contain a blade released during engine operation. Composite materials offer the potential for reducing the weight of the case. Efficient design, test, and analysis methods are needed to efficiently evaluate the large number of potential composite materials and design concepts. The type of damage expected in a composite case under blade-out conditions was evaluated using a subscale test in which a glass/epoxy composite half-ring target was impacted with a wedge-shaped titanium projectile. Fiber shearing occurred near points of contact between the projectile and target. Delamination and tearing occurred on a larger scale. These damage modes were reproduced in a simpler test in which flat glass/epoxy composites were impacted with a blunt cylindrical projectile. A surface layer of ceramic eliminated fiber shear fracture but did not reduce delamination. Tests on 3D woven carbon/epoxy composites indicated that transverse reinforcement is effective in reducing delamination. A 91 cm (36 in.) diameter full-ring sub-component was proposed for larger scale testing of these and other composite concepts. Explicit, transient, finite element analyses indicated that a full-ring test is needed to simulate complete impact dynamics, but simpler tests using smaller ring sections are adequate when evaluation of initial impact damage is the primary concern.

Long-term reliability of ImPACT in professional ice hockey.

PubMed

Echemendia, Ruben J; Bruce, Jared M; Meeuwisse, Willem; Comper, Paul; Aubry, Mark; Hutchison, Michael

2016-02-01

This study sought to assess the test-retest reliability of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) across 2-4 year time intervals and evaluate the utility of a newly proposed two-factor (Speed/Memory) model of ImPACT across multiple language versions. Test-retest data were collected from non-concussed National Hockey League (NHL) players across 2-, 3-, and 4-year time intervals. The two-factor model was examined using different language versions (English, French, Czech, Swedish) of the test using a one-year interval, and across 2-4 year intervals using the English version of the test. The two-factor Speed index improved reliability across multiple language versions of ImPACT. The Memory factor also improved but reliability remained below the traditional cutoff of .70 for use in clinical decision-making. ImPACT reliabilities remained low (below .70) regardless of whether the four-composite or the two-factor model was used across 2-, 3-, and 4-year time intervals. The two-factor approach increased ImPACT's one-year reliability over the traditional four-composite model among NHL players. The increased stability in test scores improves the test's ability to detect cognitive changes following injury, which increases the diagnostic utility of the test and allows for better return to play decision-making by reducing the risk of exposing an athlete to additional trauma while the brain may be at a heightened vulnerability to such trauma. Although the Speed Index increases the clinical utility of the test, the stability of the Memory index remains low. Irrespective of whether the two-factor or traditional four-composite approach is used, these data suggest that new baselines should occur on a yearly basis in order to maximize clinical utility.

Materials and processes laboratory composite materials characterization task, part 1. Damage tolerance

NASA Technical Reports Server (NTRS)

Nettles, A. T.; Tucker, D. S.; Patterson, W. J.; Franklin, S. W.; Gordon, G. H.; Hart, L.; Hodge, A. J.; Lance, D. G.; Russel, S. S.

1991-01-01

A test run was performed on IM6/3501-6 carbon-epoxy in which the material was processed, machined into specimens, and tested for damage tolerance capabilities. Nondestructive test data played a major role in this element of composite characterization. A time chart was produced showing the time the composite material spent within each Branch or Division in order to identify those areas which produce a long turnaround time. Instrumented drop weight testing was performed on the specimens with nondestructive evaluation being performed before and after the impacts. Destructive testing in the form of cross-sectional photomicrography and compression-after-impact testing were used. Results show that the processing and machining steps needed to be performed more rapidly if data on composite material is to be collected within a reasonable timeframe. The results of the damage tolerance testing showed that IM6/3501-6 is a brittle material that is very susceptible to impact damage.

Cognitive Skills, Student Achievement Tests, and Schools

PubMed Central

Finn, Amy S.; Kraft, Matthew A.; West, Martin R.; Leonard, Julia A.; Bish, Crystal E.; Martin, Rebecca E.; Sheridan, Margaret A.; Gabrieli, Christopher F. O.; Gabrieli, John D. E.

2014-01-01

Cognitive skills predict academic performance, so schools that improve academic performance might also improve cognitive skills. To investigate the impact schools have on both academic performance and cognitive skills, we related standardized achievement test scores to measures of cognitive skills in a large sample (N=1,367) of 8th-grade students attending traditional, exam, and charter public schools. Test scores and gains in test scores over time correlated with measures of cognitive skills. Despite wide variation in test scores across schools, differences in cognitive skills across schools were negligible after controlling for 4th-grade test scores. Random offers of enrollment to over-subscribed charter schools resulted in positive impacts of such school attendance on math achievement, but had no impact on cognitive skills. These findings suggest that schools that improve standardized achievement tests do so primarily through channels other than cognitive skills. PMID:24434238

Mechanical Impact Testing: A Statistical Measurement

NASA Technical Reports Server (NTRS)

Engel, Carl D.; Herald, Stephen D.; Davis, S. Eddie

2005-01-01

In the decades since the 1950s, when NASA first developed mechanical impact testing of materials, researchers have continued efforts to gain a better understanding of the chemical, mechanical, and thermodynamic nature of the phenomenon. The impact mechanism is a real combustion ignition mechanism that needs understanding in the design of an oxygen system. The use of test data from this test method has been questioned due to lack of a clear method of application of the data and variability found between tests, material batches, and facilities. This effort explores a large database that has accumulated over a number of years and explores its overall nature. Moreover, testing was performed to determine the statistical nature of the test procedure to help establish sample size guidelines for material characterization. The current method of determining a pass/fail criterion based on either light emission or sound report or material charring is questioned.

The Impact of an Electronic Expensive Test Notification.

PubMed

Riley, Jacquelyn D; Stanley, Glenn; Wyllie, Robert; Kottke-Marchant, Kandice; Procop, Gary W

2018-04-25

The impact of clinical decision support tools (CDSTs) that display test cost information has been variable. We retrospectively analyzed the 3-year impact of a passive CDST that notified providers when the test order cost was $1,000 or more. We determined the most common expensive tests ordered, the frequency with which providers abandoned the order after notification, and the costs saved through this intervention. The average monthly abandonment rate was 12.5% (2014), 12.9% (2015), and 14.3% (2016). The cost savings from tests not performed for this 3-year period was $696,007. Molecular hematopathology assays were the most frequently ordered tests, with variable abandonment rates. Although this CDST was passive (ie, could be overridden at the point of order entry) and was associated with a relatively low abandonment rate, it achieved a considerable cost savings each year since each abandoned test saved the institution $1,000 or more.

Effect of education and language on baseline concussion screening tests in professional baseball players.

PubMed

Jones, Nathaniel S; Walter, Kevin D; Caplinger, Roger; Wright, Daniel; Raasch, William G; Young, Craig

2014-07-01

The purpose of the present study was to investigate the possible effects of sociocultural influences, specifically pertaining to language and education, on baseline neuropsychological concussion testing as obtained via immediate postconcussion assessment and cognitive testing (ImPACT) of players from a professional baseball team. A retrospective chart review. Baseline testing of a professional baseball organization. Four hundred five professional baseball players. Age, languages spoken, hometown country location (United States/Canada vs overseas), and years of education. The 5 ImPACT composite scores (verbal memory, visual memory, visual motor speed, reaction time, impulse control) and ImPACT total symptom score from the initial baseline testing. The result of t tests revealed significant differences (P < 0.05) when comparing native English to native Spanish speakers in many scores. Even when corrected for education, the significant differences (P < 0.05) remained in some scores. Sociocultural differences may result in differences in computer-based neuropsychological testing scores.

Perceptions and performance using computer-based testing: One institution's experience.

PubMed

Bloom, Timothy J; Rich, Wesley D; Olson, Stephanie M; Adams, Michael L

2018-02-01

The purpose of this study was to evaluate student and faculty perceptions of the transition to a required computer-based testing format and to identify any impact of this transition on student exam performance. Separate questionnaires sent to students and faculty asked about perceptions of and problems with computer-based testing. Exam results from program-required courses for two years prior to and two years following the adoption of computer-based testing were compared to determine if this testing format impacted student performance. Responses to Likert-type questions about perceived ease of use showed no difference between students with one and three semesters experience with computer-based testing. Of 223 student-reported problems, 23% related to faculty training with the testing software. Students most commonly reported improved feedback (46% of responses) and ease of exam-taking (17% of responses) as benefits to computer-based testing. Faculty-reported difficulties were most commonly related to problems with student computers during an exam (38% of responses) while the most commonly identified benefit was collecting assessment data (32% of responses). Neither faculty nor students perceived an impact on exam performance due to computer-based testing. An analysis of exam grades confirmed there was no consistent performance difference between the paper and computer-based formats. Both faculty and students rapidly adapted to using computer-based testing. There was no evidence that switching to computer-based testing had any impact on student exam performance. Copyright © 2017 Elsevier Inc. All rights reserved.

FOD impact testing of composite fan blades

NASA Technical Reports Server (NTRS)

Johns, R. H.

1974-01-01

The results of impact tests on large, fiber composite fan blades for aircraft turbofan engine applications are discussed. Solid composite blades of two different sizes and designs were tested. Both graphite/epoxy and boron/epoxy were evaluated. In addition, a spar-shell blade design was tested that had a boron/epoxy shell bonded to a titanium spar. All blades were tested one at a time in a rotating arm rig to simulate engine operating conditions. Impacting media included small gravel, two inch diameter ice balls, gelatin and RTV foam-simulated birds, as well as starlings and pigeons. The results showed little difference in performance between the graphite and boron/epoxy blades. The results also indicate that composite blades may be able to tolerate ice ball and small bird impacts but need improvement to tolerate birds in the small duck and larger category.

FOD impact testing of composite fan blades

NASA Technical Reports Server (NTRS)

Johns, R. H.

1974-01-01

The results of impact tests on large, fiber composite fan blades for aircraft turbofan engine applications are discussed. Solid composite blades of two different sizes and designs were tested. Both graphite/epoxy and boron/epoxy were evaluated. In addition, a spar-shell blade design was tested that had a boron/epoxy shell bonded to a titanium spar. All blades were tested one at a time in a rotating arm rig to simulate engine operating conditions. Impacting media included small gravel, two inch diameter ice balls, gelatin, and RTV foam-simulated birds, as well as starlings and pigeons. The results showed little difference in performance between the graphite and boron/epoxy blades. The results also indicate that composite blades may be able to tolerate ice ball and small bird impacts but need improvement to tolerate birds in the small duck and larger category.

Impact testing on composite fan blades

NASA Technical Reports Server (NTRS)

Johns, R. H.

1974-01-01

The results of impact tests on large, fiber composite fan blades for aircraft turbofan engine applications are discussed. Solid composite blades of two different sizes and designs were tested. Both graphite/epoxy and boron/epoxy were evaluated. In addition, a spar-shell blade design was tested that had a boron/epoxy shell bonded to a titanium spar. All blades were tested one at a time in a rotating arm rig to simulate engine operating conditions. Impacting media included small gravel, two inch diameter ice balls, gelatin and RTV foam-simulated birds, as well as starlings and pigeons. The results showed little difference in performance between the graphite and boron/epoxy blades. The results also indicate that composite blades may be able to tolerate ice ball and small bird impacts but need improvement to tolerate birds in the small duck and larger category.

Characterization of pediatric wheelchair kinematics and wheelchair tiedown and occupant restraint system loading during rear impact.

PubMed

Fuhrman, Susan I; Karg, Patricia; Bertocci, Gina

2010-04-01

This study characterizes pediatric wheelchair kinematic responses and wheelchair tiedown and occupant restraint system (WTORS) loading during rear impact. It also examines the kinematic and loading effects of wheelchair headrest inclusion in rear impact. In two separate rear-impact test scenarios, identical WC19-compliant manual pediatric wheelchairs were tested using a seated Hybrid III 6-year-old anthropomorphic test device (ATD) to evaluate wheelchair kinematics and WTORS loading. Three wheelchairs included no headrests, and three were equipped with slightly modified wheelchair-mounted headrests. Surrogate WTORS properly secured the wheelchairs; three-point occupant restraints properly restrained the ATD. All tests used a 26km/h, 11g rear-impact test pulse. Headrest presence affected wheelchair kinematics and WTORS loading; headrest-equipped wheelchairs had greater mean seatback deflections, mean peak front and rear tiedown loads and decreased mean lap belt loads. Rear-impact tiedown loads differed from previously measured loads in frontal impact, with comparable tiedown load levels reversed in frontal and rear impacts. The front tiedowns in rear impact had the highest mean peak loads despite lower rear-impact severity. These outcomes have implications for wheelchair and tiedown design, highlighting the need for all four tiedowns to have an equally robust design, and have implications in the development of rear-impact wheelchair transportation safety standards. Copyright 2009 IPEM. Published by Elsevier Ltd. All rights reserved.

HIV Testing Among Young People Aged 16-24 in South Africa: Impact of Mass Media Communication Programs.

PubMed

Do, Mai; Figueroa, Maria Elena; Lawrence Kincaid, D

2016-09-01

Knowing one's serostatus is critical in the HIV prevention, care and treatment continuum. This study examines the impact of communication programs on HIV testing in South Africa. Data came from 2204 young men and women aged 16-24 who reported to be sexually active in a population based survey. Structural equation modeling was used to test the directions and causal pathways between communication program exposure, HIV testing discussion, and having a test in the last 12 months. Bivariate and multivariate probit regressions provided evidence of exogeneity of communication exposure and the two HIV-related outcomes. One in three sampled individuals had been tested in the last 12 months. Communication program exposure only had an indirect effect on getting tested by encouraging young people to talk about testing. The study suggests that communication programs may create an environment that supports open HIV-related discussions and may have a long-term impact on behavior change.

Comparison of ALE and SPH Simulations of Vertical Drop Tests of a Composite Fuselage Section into Water

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fuchs, Yvonne T.

2008-01-01

Simulation of multi-terrain impact has been identified as an important research area for improved prediction of rotorcraft crashworthiness within the NASA Subsonic Rotary Wing Aeronautics Program on Rotorcraft Crashworthiness. As part of this effort, two vertical drop tests were conducted of a 5-ft-diameter composite fuselage section into water. For the first test, the fuselage section was impacted in a baseline configuration without energy absorbers. For the second test, the fuselage section was retrofitted with a composite honeycomb energy absorber. Both tests were conducted at a nominal velocity of 25-ft/s. A detailed finite element model was developed to represent each test article and water impact was simulated using both Arbitrary Lagrangian Eulerian (ALE) and Smooth Particle Hydrodynamics (SPH) approaches in LS-DYNA, a nonlinear, explicit transient dynamic finite element code. Analytical predictions were correlated with experimental data for both test configurations. In addition, studies were performed to evaluate the influence of mesh density on test-analysis correlation.

Size Effects in Impact Damage of Composite Sandwich Panels

NASA Technical Reports Server (NTRS)

Dobyns, Alan; Jackson, Wade

2003-01-01

Panel size has a large effect on the impact response and resultant damage level of honeycomb sandwich panels. It has been observed during impact testing that panels of the same design but different panel sizes will show large differences in damage when impacted with the same impact energy. To study this effect, a test program was conducted with instrumented impact testing of three different sizes of sandwich panels to obtain data on panel response and residual damage. In concert with the test program. a closed form analysis method was developed that incorporates the effects of damage on the impact response. This analysis method will predict both the impact response and the residual damage of a simply-supported sandwich panel impacted at any position on the panel. The damage is incorporated by the use of an experimental load-indentation curve obtained for the face-sheet/honeycomb and indentor combination under study. This curve inherently includes the damage response and can be obtained quasi-statically from a rigidly-backed specimen or a specimen with any support conditions. Good correlation has been obtained between the test data and the analysis results for the maximum force and residual indentation. The predictions can be improved by using a dynamic indentation curve. Analyses have also been done using the MSC/DYTRAN finite element code.

Results and analysis of the switchyard impact tests

DOT National Transportation Integrated Search

1980-01-01

This report presents the results and analysis of series 3 through 7 and series 10 of the FRA/RPI/AAR Switchyard Impact Tests. The test results and analysis are used to evaluate the head shield and the shelf-E coupler as protective devices for hazardo...

Passenger rail train-to-train impact test. Volume 1 : overview and selected results

DOT National Transportation Integrated Search

2003-07-01

This report describes the results of the train-to-train impact test conducted at the Federal Railroad Administration's Transportation Technology Center in Pueblo, Colorado on January 31, 2002. In this test, a cab car-led train, initially moving at 30...

Train-to-train impact test : analysis of structural measurements

DOT National Transportation Integrated Search

2002-11-17

This paper describes the results of the train-to-train impact test conducted at the Transportation Technology Center in Pueblo, Colorado on January 31, 2002. In this test, a cab car-led train, initially moving at 30 mph, collided with a standing loco...

Economic impact of 21-gene recurrence score testing on early-stage breast cancer in Ireland.

PubMed

Smyth, Lillian; Watson, Geoff; Walsh, Elaine M; Kelly, Catherine M; Keane, Maccon; Kennedy, M John; Grogan, Liam; Hennessy, Bryan T; O'Reilly, Seamus; Coate, Linda E; O'Connor, Miriam; Quinn, Cecily; Verleger, Katharina; Schoeman, Olaf; O'Reilly, Susan; Walshe, Janice M

2015-10-01

The 21-gene test is a validated multi-gene diagnostic test that predicts chemotherapy (CT) benefit in oestrogen receptor positive (ER+), lymph node-negative (N0) breast cancer (BC) patients (pts). Ireland was the first public health care system to reimburse this test in Europe. Study objectives were to assess the impact of this test on decision-making and to analyse the economic impact of testing. Between October 2011 and February 2013, a national, retrospective, cross-sectional observational study of ER+, N0 BC pts tested with the 21-gene test was conducted. Surveyed breast medical oncologists, provided the assumption for the decision impact analysis that grade (G) 1 pts would not have received CT before testing and G2/3 pts would have received CT before testing. Descriptive statistical analyses were performed. 592 pts were identified; Low, intermediate and high recurrence score were identified in 53, 36 and 10 % pts, respectively. 384 (70 %) pts had G2, 129 (22 %) G3 and 76 (13 %) G1 tumours. Post testing, 345 pts (59 %) experienced a change in CT decision; 339 changed to hormone therapy alone and 6 advised to receive CT. 172 (30 %) pts received CT, 12 (3.9 %) of pts with low scores, 108 (50.9 %) of intermediate risk and 50 (90.9 %) of pts with high risk scores. Net reduction in CT use was 58 % and net savings achieved were €793,565. Since public reimbursement, the introduction of the 21-gene test has resulted in a significant reduction in chemotherapy administration and cost savings for the Irish public healthcare system.

Elemental Water Impact Test: Phase 2 36-Inch Aluminum Tank Head

NASA Technical Reports Server (NTRS)

Vassilakos, Gregory J.

2014-01-01

Spacecraft are being designed based on LS-DYNA simulations of water landing impacts. The Elemental Water Impact Test (EWIT) series was undertaken to assess the accuracy of LS-DYNA water impact simulations. EWIT Phase 2 featured a 36-inch aluminum tank head. The tank head was outfitted with one accelerometer, twelve pressure transducers, three string potentiometers, and four strain gages. The tank head was dropped from heights of 1 foot and 2 feet. The focus of this report is the correlation of analytical models against test data. As a measure of prediction accuracy, peak responses from the baseline LS-DYNA model were compared to peak responses from the tests.

Using Numerical Modeling to Simulate Space Capsule Ground Landings

NASA Technical Reports Server (NTRS)

Heymsfield, Ernie; Fasanella, Edwin L.

2009-01-01

Experimental work is being conducted at the National Aeronautics and Space Administration s (NASA) Langley Research Center (LaRC) to investigate ground landing capabilities of the Orion crew exploration vehicle (CEV). The Orion capsule is NASA s replacement for the Space Shuttle. The Orion capsule will service the International Space Station and be used for future space missions to the Moon and to Mars. To evaluate the feasibility of Orion ground landings, a series of capsule impact tests are being performed at the NASA Langley Landing and Impact Research Facility (LandIR). The experimental results derived at LandIR provide means to validate and calibrate nonlinear dynamic finite element models, which are also being developed during this study. Because of the high cost and time involvement intrinsic to full-scale testing, numerical simulations are favored over experimental work. Subsequent to a numerical model validated by actual test responses, impact simulations will be conducted to study multiple impact scenarios not practical to test. Twenty-one swing tests using the LandIR gantry were conducted during the June 07 through October 07 time period to evaluate the Orion s impact response. Results for two capsule initial pitch angles, 0deg and -15deg , along with their computer simulations using LS-DYNA are presented in this article. A soil-vehicle friction coefficient of 0.45 was determined by comparing the test stopping distance with computer simulations. In addition, soil modeling accuracy is presented by comparing vertical penetrometer impact tests with computer simulations for the soil model used during the swing tests.

Invalid performance and the ImPACT in national collegiate athletic association division I football players.

PubMed

Szabo, Ashley J; Alosco, Michael L; Fedor, Andrew; Gunstad, John

2013-01-01

Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a computerized cognitive test battery commonly used for concussion evaluation. An important aspect of these procedures is baseline testing, but researchers have suggested that many users do not use validity indices to ensure adequate effort during testing. No one has examined the prevalence of invalid performance for college football players. To examine the prevalence of invalid scores on ImPACT testing. Cross-sectional study. National Collegiate Athletic Association Division I university. A total of 159 athletes (age = 20.3 ± 1.41 years; range = 17.8-23.7 years) from a Division I collegiate football team participated. An informational intervention regarding the importance of concussion testing to promote safety was administered before testing for the most recent season. We examined preseason ImPACT testing data across a 3-year period (total assessments = 269). Based on invalid and sandbagging indices denoted by the ImPACT manual, protocols were examined to indicate how many invalid indices each athlete had. A total of 27.9% (n = 75) of assessments were suggestive of invalid scores, with 4.1% (n = 11) suggesting invalid responding only, 17.5% (n = 47) indicating "sandbagging" only, and 6.3% (n = 17) showing both invalid and sandbagging responding. The informational intervention did not reduce the prevalence of invalid responding. These findings highlight the need for further information about the ImPACT validity indices and whether they truly reflect poor effort. Future work is needed to identify practices to reliably target and reduce invalid responding.

Orion Swing Drop 6

NASA Image and Video Library

2017-09-25

Water impact test of an 18,000-pound (8,165 kilogram) test version of the Orion spacecraft at NASA's Langley Research Center. NASA is swing drop testing this Orion capsule mock-up at Langley's Hydro Impact Basin to certify the actual Orion spacecraft for water landings. In a series of tests, Orion is being dropped in a variety of different conditions to help fine-tune NASA's predictions of Orion's landing loads.

Comparing Learning Style to Performance in On-Line Teaching: Impact of Proctored v. Un-Proctored Testing

ERIC Educational Resources Information Center

Wellman, Gregory S.

2005-01-01

The purpose of this study was to examine the impact that proctored versus un-proctored testing would have on learning for an on-line content module; and examine the relationship between LASSI variables and learning. A randomized, pre-test/post-test control group design was employed. College students in a pharmacy curriculum, were randomized to two…

Low Velocity Impact Testing and Nondestructive Evaluation of Transparent Materials

NASA Astrophysics Data System (ADS)

Brennan, R. E.; Green, W. H.

2011-06-01

Advanced transparent materials are used in protective systems for enhancing the survivability of ground vehicles, air vehicles, and personnel in applications such as face shields, riot gear, and vehicle windows. Low velocity impact damage can limit visibility and compromise the structural integrity of a transparent system, increasing the likelihood of further damage or penetration from a high velocity impact strike. For this reason, it is critical to determine damage tolerance levels of transparent systems to indicate whether or not a component should be replaced. In this study, transparent laminate systems will be tested by comparing baseline conditions to experimentally controlled damage states. Destructive testing including air gun and sphere impact testing will be used to replicate low velocity impacts in the field. Characterization of the damaged state will include basic visual inspection as well as nondestructive techniques including cross-polarization, x-ray, and ultrasound. The combination of destructive testing and characterization of the resulting damage can help to establish a damage acceptance criterion for materials used in protective systems.

Hypervelocity Impact (HVI). Volume 8; Tile Small Targets A-1, Ag-1, B-1, and Bg-1

NASA Technical Reports Server (NTRS)

Gorman, Michael R.; Ziola, Steven M.

2007-01-01

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Targets A-1, Ag-1, B-1, and Bg-1 was to study hypervelocity impacts on the reinforced Shuttle Heat Shield Tiles of the Wing. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Hypervelocity Impact (HVI). Volume 2; WLE Small-Scale Fiberglass Panel Flat Multi-Layer Targets A-1, A-2, and B-1

NASA Technical Reports Server (NTRS)

Gorman, Michael R.; Ziola, Steven M.

2007-01-01

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Targets A-1, A-2, and B-2 was to study hypervelocity impacts through multi-layered panels simulating Whipple shields on spacecraft. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Dynamic Crushing Response of Closed-cell Aluminium Foam at Variable Strain Rates

NASA Astrophysics Data System (ADS)

Islam, M. A.; Kader, M. A.; Escobedo, J. P.; Hazell, P. J.; Appleby-Thomas, G. J.; Quadir, M. Z.

2015-06-01

The impact response of aluminium foams is essential for assessing their crashworthiness and energy absorption capacity for potential applications. The dynamic compactions of closed-cell aluminium foams (CYMAT) have been tested at variable strain rates. Microstructural characterization has also been carried out. The low strain rate impact test has been carried out using drop weight experiments while the high strain compaction test has been carried out via plate impact experiments. The post impacted samples have been examined using optical and electron microscopy to observe the microstructural changes during dynamic loading. This combination of dynamic deformation during impact and post impact microstructural analysis helped to evaluate the pore collapse mechanism and impact energy absorption characteristics.

Determination of Acreage Thermal Protection Foam Loss From Ice and Foam Impacts

NASA Technical Reports Server (NTRS)

Carney, Kelly S.; Lawrence, Charles

2015-01-01

A parametric study was conducted to establish Thermal Protection System (TPS) loss from foam and ice impact conditions similar to what might occur on the Space Launch System. This study was based upon the large amount of testing and analysis that was conducted with both ice and foam debris impacts on TPS acreage foam for the Space Shuttle Project External Tank. Test verified material models and modeling techniques that resulted from Space Shuttle related testing were utilized for this parametric study. Parameters varied include projectile mass, impact velocity and impact angle (5 degree and 10 degree impacts). The amount of TPS acreage foam loss as a result of the various impact conditions is presented.

Validation of the ENSCO surrogate bogie vehicle, FOIL test numbers 92F028 through 92F031

DOT National Transportation Integrated Search

1994-11-01

This document contains the results from four crash tests conducted at the Federal Outdoor Impact Laboratory (FOIL) located at the Turner-Fairbank Highway Research Center in McLean, Virginia. The crash tests involved two reusable bogie vehicles impact...

A 640 foot per second impact test of a two foot diameter model nuclear reactor containment system without fracture

NASA Technical Reports Server (NTRS)

Puthoff, R. L.

1971-01-01

An impact test was conducted on an 1142 pound 2 foot diameter sphere model. The purpose of this test was to determine the feasibility of containing the fission products of a mobile reactor in an impact. The model simulated the reactor core, energy absorbing gamma shielding, neutron shielding and the containment vessel. It was impacted against an 18,000 pound reinforced concrete block. The model was significantly deformed and the concrete block demolished. No leaks were detected nor cracks observed in the model after impact.

Dynamic Finite Element Predictions for Mars Sample Return Cellular Impact Test #4

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Billings, Marcus D.

2001-01-01

The nonlinear finite element program MSC.Dytran was used to predict the impact pulse for (he drop test of an energy absorbing cellular structure. This pre-test simulation was performed to aid in the design of an energy absorbing concept for a highly reliable passive Earth Entry Vehicle (EEV) that will directly impact the Earth without a parachute. In addition, a goal of the simulation was to bound the acceleration pulse produced and delivered to the simulated space cargo container. EEV's are designed to return materials from asteroids, comets, or planets for laboratory analysis on Earth. The EEV concept uses an energy absorbing cellular structure designed to contain and limit the acceleration of space exploration samples during Earth impact. The spherical shaped cellular structure is composed of solid hexagonal and pentagonal foam-filled cells with hybrid graphite-epoxy/Kevlar cell walls. Space samples fit inside a smaller sphere at the enter of the EEV's cellular structure. The material models and failure criteria were varied to determine their effect on the resulting acceleration pulse. Pre-test analytical predictions using MSC.Dytran were compared with the test results obtained from impact test #4 using bungee accelerator located at the NASA Langley Research Center Impact Dynamics Research Facility. The material model used to represent the foam and the proper failure criteria for the cell walls were critical in predicting the impact loads of the cellular structure. It was determined that a FOAMI model for the foam and a 20% failure strain criteria for the cell walls gave an accurate prediction of the acceleration pulse for drop test #4.

Measuring cognitive change with ImPACT: the aggregate baseline approach.

PubMed

Bruce, Jared M; Echemendia, Ruben J; Meeuwisse, Willem; Hutchison, Michael G; Aubry, Mark; Comper, Paul

2017-11-01

The Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) is commonly used to assess baseline and post-injury cognition among athletes in North America. Despite this, several studies have questioned the reliability of ImPACT when given at intervals employed in clinical practice. Poor test-retest reliability reduces test sensitivity to cognitive decline, increasing the likelihood that concussed athletes will be returned to play prematurely. We recently showed that the reliability of ImPACT can be increased when using a new composite structure and the aggregate of two baselines to predict subsequent performance. The purpose of the present study was to confirm our previous findings and determine whether the addition of a third baseline would further increase the test-retest reliability of ImPACT. Data from 97 English speaking professional hockey players who had received at least 4 ImPACT baseline evaluations were extracted from a National Hockey League Concussion Program database. Linear regression was used to determine whether each of the first three testing sessions accounted for unique variance in the fourth testing session. Results confirmed that the aggregate baseline approach improves the psychometric properties of ImPACT, with most indices demonstrating adequate or better test-retest reliability for clinical use. The aggregate baseline approach provides a modest clinical benefit when recent baselines are available - and a more substantial benefit when compared to approaches that obtain baseline measures only once during the course of a multi-year playing career. Pending confirmation in diverse samples, neuropsychologists are encouraged to use the aggregate baseline approach to best quantify cognitive change following sports concussion.

Marshall Space Flight Center's Impact Testing Facility Capabilities

NASA Technical Reports Server (NTRS)

Evans, Steve; Finchum, Andy; Hubbs, Whitney; Gray, Perry

2008-01-01

Marshall Space Flight Center's (MSFC) Impact Testing Facility (ITF) serves as an important installation for space and missile related materials science research. The ITF was established and began its research in spacecraft debris shielding in the early 1960s, then played a major role in the International Space Station debris shield development. As NASA became more interested in launch debris and in-flight impact concerns, the ITF grew to include research in a variety of impact genres. Collaborative partnerships with the DoD led to a wider range of impact capabilities being relocated to MSFC as a result of the closure of Particle Impact Facilities in Santa Barbara, California, The Particle Impact Facility had a 30 year history in providing evaluations of aerospace materials and components during flights through rain, ice, and solid particle environments at subsonic through hypersonic velocities. The facility's unique capabilities were deemed a 'National Asset' by the DoD, The ITF now has capabilities including environmental, ballistic, and hypervelocity impact testing utilizing an array of air, powder, and two-stage light gas guns to accommodate a variety of projectile and target types and sizes. Relocated test equipment was dated and in need of upgrade. Numerous upgrades including new instrumentation, triggering circuitry, high speed photography, and optimized sabot designs have been implemented. Other recent research has included rain drop demise characterization tests to obtain data for inclusion in on-going model development. Future ITF improvements will be focused on continued instrumentation and performance enhancements. These enhancements will allow further, more in-depth, characterization of rain drop demise characterization and evaluation of ice crystal impact. Performance enhancements also include increasing the upper velocity limit of the current environmental guns to allow direct environmental simulation for missile components. The current and proposed ITF capabilities range from rain to micrometeoroids allowing the widest test parameter range possible for materials investigations in support of space, atmospheric, and ground environments. These test capabilities including hydrometeor, single/multi-particle, ballistic gas guns, exploding wire gun, and light gas guns combined with Smooth Particle Hydrodynamics Code (SPHC) simulations represent the widest range of impact test capabilities in the country.

Marshall Space Flight Center's Impact Testing Facility Capabilities

NASA Technical Reports Server (NTRS)

Evans, Steve; Finchum, Andy; Hubbs, Whitney

2008-01-01

Marshall Space Flight Center's (MSFC) Impact Testing Facility (ITF) serves as an important installation for space and missile related materials science research. The ITF was established and began its research in spacecraft debris shielding in the early 1960% then played a major role in the International Space Station debris shield development. As NASA became more interested in launch debris and in-flight impact concerns, the ITF grew to include research in a variety of impact genres. Collaborative partnerships with the DoD led to a wider range of impact capabilities being relocated to MSFC as a result of the closure of Particle Impact Facilities in Santa Barbara, California. The Particle Impact Facility had a 30 year history in providing evaluations of aerospace materials and components during flights through rain, ice, and solid particle environments at subsonic through hypersonic velocities. The facility's unique capabilities were deemed a "National Asset" by the DoD. The ITF now has capabilities including environmental, ballistic, and hypervelocity impact testing utilizing an array of air, powder, and two-stage light gas guns to accommodate a variety of projectile and target types and sizes. Relocated test equipment was dated and in need of upgrade. Numerous upgrades including new instrumentation, triggering circuitry, high speed photography, and optimized sabot designs have been implemented. Other recent research has included rain drop demise characterization tests to obtain data for inclusion in on-going model development. Future ITF improvements will be focused on continued instrumentation and performance enhancements. These enhancements will allow further, more in-depth, characterization of rain drop demise characterization and evaluation of ice crystal impact. Performance enhancements also include increasing the upper velocity limit of the current environmental guns to allow direct environmental simulation for missile components. The current and proposed ITF capabilities range from rain to micrometeoroids allowing the widest test parameter range possible for materials investigations in support of space, atmospheric, and ground environments. These test capabilities including hydrometeor, single/multi-particle, ballistic gas grins, exploding wire gun, and light gas guns combined with Smooth Particle Hydrodynamics Code (SPHC) simulations represent the widest range of impact test capabilities in the country.

Composite Overwrap Fragmentation Observations, Concerns, and Recommendations

NASA Technical Reports Server (NTRS)

Bangham, Mike; Hovater, Mary

2017-01-01

A series of test activities has raised some concerns about the generation of orbital debris caused by failures of composite overwrapped pressure vessels (COPVs). These tests have indicated that a large number of composite fragments can be produced by either pressure burst failures or by high-speed impacts. A review of prior high-speed tests with COPV indicates that other tests have produced large numbers of composite fragments. As was the case with the test referenced here, the tests tended to produce a large number of small composite fragments with relatively low velocities induced by the impact and or gas expansion.

Impact evaluation of composite floor sections

NASA Technical Reports Server (NTRS)

Boitnott, Richard L.; Fasanella, Edwin L.

1989-01-01

Graphite-epoxy floor sections representative of aircraft fuselage construction were statically and dynamically tested to evaluate their response to crash loadings. These floor sections were fabricated using a frame-stringer design typical of present aluminum aircraft without features to enhance crashworthiness. The floor sections were tested as part of a systematic research program developed to study the impact response of composite components of increasing complexity. The ultimate goal of the research program is to develop crashworthy design features for future composite aircraft. Initially, individual frames of six-foot diameter were tested both statically and dynamically. The frames were then used to construct built-up floor sections for dynamic tests at impact velocities of approximately 20 feet/sec to simulate survivable crash velocities. In addition, static tests were conducted to gain a better understanding of the failure mechanisms seen in the dynamic tests.

A Prospective, Longitudinal Study of the Impact of GJB2/GJB6 Genetic Testing on the Beliefs and Attitudes of Parents of Deaf and Hard-of-Hearing Infants

PubMed Central

Palmer, Christina G.S.; Martinez, Ariadna; Fox, Michelle; Zhou, Jin; Shapiro, Nina; Sininger, Yvonne; Grody, Wayne W.; Schimmenti, Lisa A.

2010-01-01

There are limited data on the impact of incorporating genetic counseling and testing into the newborn hearing screening process. We report on results from a prospective, longitudinal study to determine the impact of genetic counseling and GJB2/GJB6 genetic testing on parental knowledge, attitudes, and beliefs about genetic testing. One hundred thirty culturally hearing parents of 93 deaf or hard-of-hearing children ages 0 – 3 years primarily identified through newborn hearing screening received pre- and post-test genetic counseling for GJB2 and GJB6. Parents completed questionnaires following pre-test counseling, and 1- and 6-months post-test result disclosure. Results indicate that following pre-test counseling all parents perceived benefits to genetic testing. While parents who received positive results continued to perceive benefits from testing, perceived benefit declined among parents who received inconclusive or negative results. Parents did not perceive genetic testing as harmful following pre-test counseling or receipt of test results. Parents who received positive test results performed better in understanding recurrence and causation of their child’s deafness and indicated greater interest in prenatal genetic testing than those who received inconclusive or negative test results. Parents felt that pediatricians and audiologists should inform parents of genetic testing availability; however, there was no consensus on timing of this discussion. Thus culturally hearing parents do not perceive genetic testing of their deaf or hard-of-hearing infants/toddlers as harmful; they feel that primary care providers should discuss genetic testing with them; and positive genetic test results with genetic counseling give rise to better understanding and perceived benefit than negative or inconclusive results. PMID:19449415

A prospective, longitudinal study of the impact of GJB2/GJB6 genetic testing on the beliefs and attitudes of parents of deaf and hard-of-hearing infants.

PubMed

Palmer, Christina G S; Martinez, Ariadna; Fox, Michelle; Zhou, Jin; Shapiro, Nina; Sininger, Yvonne; Grody, Wayne W; Schimmenti, Lisa A

2009-06-01

There are limited data on the impact of incorporating genetic counseling and testing into the newborn hearing screening process. We report on results from a prospective, longitudinal study to determine the impact of genetic counseling and GJB2/GJB6 genetic testing on parental knowledge, attitudes, and beliefs about genetic testing. One hundred thirty culturally hearing parents of 93 deaf or hard-of-hearing children ages 0-3 years primarily identified through newborn hearing screening received pre- and post-test genetic counseling for GJB2 and GJB6. Parents completed questionnaires following pre-test counseling, and 1- and 6-month post-test result disclosure. Results indicate that following pre-test counseling all parents perceived benefits to genetic testing. While parents who received positive results continued to perceive benefits from testing, perceived benefit declined among parents who received inconclusive or negative results. Parents did not perceive genetic testing as harmful following pre-test counseling or receipt of test results. Parents who received positive test results performed better in understanding recurrence and causation of their child's deafness and indicated greater interest in prenatal genetic testing than those who received inconclusive or negative test results. Parents felt that pediatricians and audiologists should inform parents of genetic testing availability; however, there was no consensus on timing of this discussion. Thus culturally hearing parents do not perceive genetic testing of their deaf or hard-of-hearing infants/toddlers as harmful; they feel that primary care providers should discuss genetic testing with them; and positive genetic test results with genetic counseling give rise to better understanding and perceived benefit than negative or inconclusive results. (c) 2009 Wiley-Liss, Inc.

What is a realistic frontal-offset test procedure?

PubMed

Scheunert, D; Justen, R; Herrmann, R; Zeidler, F; Decker, J; Kallina, I

1994-06-01

With an increasing number of vehicles satisfying the FMVSS 208 Flat Barrier Impact Test and increasing belt usage, a high reduction of occupant injuries in general and a change from acceleration-induced to intrusion-induced injury mechanisms has been observed in Europe. The significance of intrusion-induced injury mechanisms associated with offset frontal impacts is assuming greater importance. Beginning in 1978, in response to this challenge, Mercedes-Benz has emphasized front structural countermeasures that have been found to be effective in the frequent asymmetrical frontal impacts. As an internal test, an offset impact with 40% overlap against a rigid barrier was defined. The relationship between actual accident frontal-overlap damage and barrier-test overlap values is explored in the paper. The results support the view that if a test of this type and associated design countermeasures were adopted by all vehicle manufacturers, a significant reduction of injuries would take place.

Can a short film impact HIV-related risk and stigma perceptions? Results from an experiment in Abuja, Nigeria.

PubMed

Lapinski, Maria Knight; Nwulu, Paul

2008-09-01

HIV/AIDS-related stigma is believed to result in negative social consequences for people with the disease and to be a deterrent to HIV serostatus testing. The ability of communicators to change people's stigma perceptions and subsequently impact decisions to test, however, is not well understood. Based on the entertainment-education approach, this article presents the results of a field experiment conducted in Abuja, Nigeria, testing a mediated intervention designed to reduce HIV-related stigma and risk perceptions. The results indicate that the intervention was effective relative to a control in impacting perceptions of the severity of HIV and some stigma-related attitudes, particularly for male participants; and that for this sample, risk and stigma perceptions significantly impact intentions to test for HIV. It also showed that severity perceptions mediated the relationship between viewing the film and testing intent.

Experimental and numerical study of drill bit drop tests on Kuru granite

NASA Astrophysics Data System (ADS)

Fourmeau, Marion; Kane, Alexandre; Hokka, Mikko

2017-01-01

This paper presents an experimental and numerical study of Kuru grey granite impacted with a seven-buttons drill bit mounted on an instrumented drop test machine. The force versus displacement curves during the impact, so-called bit-rock interaction (BRI) curves, were obtained using strain gauge measurements for two levels of impact energy. Moreover, the volume of removed rock after each drop test was evaluated by stereo-lithography (three-dimensional surface reconstruction). A modified version of the Holmquist-Johnson-Cook (MHJC) material model was calibrated using Kuru granite test results available from the literature. Numerical simulations of the single drop tests were carried out using the MHJC model available in the LS-DYNA explicit finite-element solver. The influence of the impact energy and additional confining pressure on the BRI curves and the volume of the removed rock is discussed. In addition, the influence of the rock surface shape before impact was evaluated using two different mesh geometries: a flat surface and a hyperbolic surface. The experimental and numerical results are compared and discussed in terms of drilling efficiency through the mechanical specific energy. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

Analysis of colliding vehicle interactions for the passenger rail train-to-train impact test

DOT National Transportation Integrated Search

2004-04-06

A full-scale train-to-train impact test was performed in : which a cab car-led passenger train traveling at 30 mph collided : with a standing locomotive-led train. During the test, the lead : cab car overrode the cab of the standing locomotive, susta...

Assessing the Impact of Clothing and Individual Equipment (CIE) on Soldier Physical, Biomechanical, and Cognitive Performance Part 1: Test Methodology

DTIC Science & Technology

2018-02-01

29 during Soldier Equipment Configuration Impact on Performance: Establishing a Test Methodology for the...Performance of Medium Rucksack Prototypes An investigation: Comparison of live-fire and weapon simulator test methodologies and the of three extremity armor

Aquatic toxicity testing for aquatic life impact assessments and recent scientific advancements

EPA Science Inventory

The focus of this presentation is to provide an overview of the use of aquatic toxicity testing for assessing possible impacts to aquatic life and how new scientific approaches are being researched. Toxicity testing of both ambient and effluent monitoring samples will be discusse...

Testing of state roadside safety systems. Volume XI, Appendix J -- Crash testing and evaluation of existing guardrail systems

DOT National Transportation Integrated Search

1999-04-01

The purpose of this study is to crash test and evaluate new or modified roadside safety hardware and, where necessary, redesign the devices to improve their impact performance. The three major areas addressed in this study are the impact performance ...

Train-to-Train Impact Test of Crash-Energy Management Passenger Rail Equipment: Occupant Experiments

DOT National Transportation Integrated Search

2006-11-06

As part of an ongoing passenger rail crashworthiness effort, : a full-scale impact test of a train with crash energy management : (CEM) passenger cars was conducted on March 23, 2006. In : this test, a train made up of a CEM cab car, four CEM coach :...

Environmental Assisted Cracking in High Hardness Armor Steel

DTIC Science & Technology

1985-09-01

Longitudinal and transverse tension tests (ASTM E8-81) utilizing flat dogbane specimens, and subsize Charpy impact tests (ASTM 23-81) were performed on part...had been obtained. Longitudinal and transverse tension tests (ASTM E8-81) utilizing flat dogbane specimens, and subsize Charpy impact tests (ASTM 23... Charpy and tensile bar surfaces. All of the optical metallography samples were prepared using standard metallographic practices. The optical specimens

49 CFR 572.200 - Instrumentation and test conditions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... mass moment of inertia of 3646 kg-cm2. (b) The test probe for the lateral abdomen impact test is the... a minimum mass moment of inertia of 3646 kg-cm2. (c) The test probe for the pelvis-iliac impact... surface 50.8 × 88.9 mm for a depth of at least 76 mm and a minimum mass moment of inertia of 5000 kg-cm2...

49 CFR 572.200 - Instrumentation and test conditions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... mass moment of inertia of 3646 kg-cm2. (b) The test probe for the lateral abdomen impact test is the... a minimum mass moment of inertia of 3646 kg-cm2. (c) The test probe for the pelvis-iliac impact... surface 50.8 × 88.9 mm for a depth of at least 76 mm and a minimum mass moment of inertia of 5000 kg-cm2...

49 CFR 572.200 - Instrumentation and test conditions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... mass moment of inertia of 3646 kg-cm2. (b) The test probe for the lateral abdomen impact test is the... a minimum mass moment of inertia of 3646 kg-cm2. (c) The test probe for the pelvis-iliac impact... surface 50.8 × 88.9 mm for a depth of at least 76 mm and a minimum mass moment of inertia of 5000 kg-cm2...

Heading Frequency Is More Strongly Related to Cognitive Performance Than Unintentional Head Impacts in Amateur Soccer Players.

PubMed

Stewart, Walter F; Kim, Namhee; Ifrah, Chloe; Sliwinski, Martin; Zimmerman, Molly E; Kim, Mimi; Lipton, Richard B; Lipton, Michael L

2018-01-01

Compared to heading, unintentional head impacts (e.g., elbow to head, head to head, head to goalpost) in soccer are more strongly related to risk of moderate to very severe Central Nervous System (CNS) symptoms. But, most head impacts associated with CNS symptoms that occur in soccer are mild and are more strongly related to heading. We tested for a differential relation of heading and unintentional head impacts with neuropsychological (NP) test performance. Active adult amateur soccer players were recruited in New York City and the surrounding areas for this repeated measures longitudinal study of individuals who were enrolled if they had 5+ years of soccer play and were active playing soccer 6+ months/year. All participants completed a baseline validated questionnaire ("HeadCount-2w"), reporting 2-week recall of soccer activity, heading and unintentional head impacts. In addition, participants also completed NP tests of verbal learning, verbal memory, psychomotor speed, attention, and working memory. Most participants also completed one or more identical follow-up protocols (i.e., HeadCount-2w and NP tests) at 3- to 6-month intervals over a 2-year period. Repeated measures General Estimating Equations (GEE) linear models were used to determine if variation in NP tests at each visit was related to variation in either heading or unintentional head impacts in the 2-week period before testing. 308 players (78% male) completed 741 HeadCount-2w. Mean (median) heading/2-weeks was 50 (17) for men and 26 (7) for women. Heading was significantly associated with poorer performance on psychomotor speed ( p  < 0.001) and attention ( p  = 0.02) tasks and was borderline significant with poorer performance on the working memory ( p  = 0.06) task. Unintentional head impacts were not significantly associated with any NP test. Results did not differ after excluding 22 HeadCount-2w with reported concussive or borderline concussive symptoms. Poorer NP test performance was consistently related to frequent heading during soccer practice and competition in the 2 weeks before testing. In contrast, unintentional head impacts incurred during soccer were not related to cognitive performance.

Hypervelocity Impact Evaluation of Metal Foam Core Sandwich Structures

NASA Technical Reports Server (NTRS)

Yasensky, John; Christiansen, Eric L.

2007-01-01

A series of hypervelocity impact (HVI) tests were conducted by the NASA Johnson Space Center (JSC) Hypervelocity Impact Technology Facility (HITF) [1], building 267 (Houston, Texas) between January 2003 and December 2005 to test the HVI performance of metal foams, as compared to the metal honeycomb panels currently in service. The HITF testing was conducted at the NASA JSC White Sands Testing Facility (WSTF) at Las Cruces, New Mexico. Eric L. Christiansen, Ph.D., and NASA Lead for Micro-Meteoroid Orbital Debris (MMOD) Protection requested these hypervelocity impact tests as part of shielding research conducted for the JSC Center Director Discretionary Fund (CDDF) project. The structure tested is a metal foam sandwich structure; a metal foam core between two metal facesheets. Aluminum and Titanium metals were tested for foam sandwich and honeycomb sandwich structures. Aluminum honeycomb core material is currently used in Orbiter Vehicle (OV) radiator panels and in other places in space structures. It has many desirable characteristics and performs well by many measures, especially when normalized by density. Aluminum honeycomb does not perform well in Hypervelocity Impact (HVI) Testing. This is a concern, as honeycomb panels are often exposed to space environments, and take on the role of Micrometeoroid / Orbital Debris (MMOD) shielding. Therefore, information on possible replacement core materials which perform adequately in all necessary functions of the material would be useful. In this report, HVI data is gathered for these two core materials in certain configurations and compared to gain understanding of the metal foam HVI performance.

Impact Testing of a Stirling Converter's Linear Alternator

NASA Technical Reports Server (NTRS)

Suarez, Vicente J.; Goodnight, Thomas W.; Hughes, William O.; Samorezov, Sergey

2002-01-01

The U.S. Department of Energy (DOE), in conjunction with the NASA John H. Glenn Research Center and Stirling Technology Company, are currently developing a Stirling convertor for a Stirling Radioisotope Generator (SRG). NASA Headquarters and DOE have identified the SRG for potential use as an advanced spacecraft power system for future NASA deep-space and Mars surface missions. Low-level dynamic impact tests were conducted at NASA Glenn Research Center's Structural Dynamics Laboratory as part of the development of this technology. The purpose of this test was to identify dynamic structural characteristics of the Stirling Technology Demonstration Convertor (TDC). This paper addresses the test setup, procedure, and results of the impact testing conducted on the Stirling TDC in May 2001.

Impact testing of a Stirling convertor's linear alternator

NASA Astrophysics Data System (ADS)

Suárez, Vicente J.; Goodnight, Thomas W.; Hughes, William O.; Samorezov, Sergey

2002-01-01

The U.S. Department of Energy (DOE), in conjunction with NASA John H. Glenn Research Center and Stirling Technology Company, are currently developing a Stirling convertor for a Stirling Radioisotope Generator (SRG). NASA Headquarters and DOE have identified the SRG for potential use as an advanced spacecraft power system for future NASA deep-space and Mars surface missions. Low-level dynamic impact tests were conducted at NASA Glenn Research Center's Structural Dynamics Laboratory as part of the development of this technology. The purpose of this test was to identify dynamic structural characteristics of the Stirling Technology Demonstration Convertor (TDC). This paper addresses the test setup, procedure and results of the impact testing conducted on the Stirling TDC in May 2001. .

Development and Calibration of a System-Integrated Rotorcraft Finite Element Model for Impact Scenarios

NASA Technical Reports Server (NTRS)

Annett, Martin S.; Horta, Lucas G.; Jackson, Karen E.; Polanco, Michael A.; Littell, Justin D.

2012-01-01

Two full-scale crash tests of an MD-500 helicopter were conducted in 2009 and 2010 at NASA Langley's Landing and Impact Research Facility in support of NASA s Subsonic Rotary Wing Crashworthiness Project. The first crash test was conducted to evaluate the performance of an externally mounted composite deployable energy absorber (DEA) under combined impact conditions. In the second crash test, the energy absorber was removed to establish baseline loads that are regarded as severe but survivable. The presence of this energy absorbing device reduced the peak impact acceleration levels by a factor of three. Accelerations and kinematic data collected from the crash tests were compared to a system-integrated finite element model of the test article developed in parallel with the test program. In preparation for the full-scale crash test, a series of sub-scale and MD-500 mass simulator tests were conducted to evaluate the impact performances of various components and subsystems, including new crush tubes and the DEA blocks. Parameters defined for the system-integrated finite element model were determined from these tests. Results from 19 accelerometers placed throughout the airframe were compared to finite element model responses. The model developed for the purposes of predicting acceleration responses from the first crash test was inadequate when evaluating more severe conditions seen in the second crash test. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used to calibrate model results for the full-scale crash test without the DEA. This combination of heuristic and quantitative methods identified modeling deficiencies, evaluated parameter importance, and proposed required model changes. The multidimensional calibration techniques presented here are particularly effective in identifying model adequacy. Acceleration results for the calibrated model were compared to test results and the original model results. There was a noticeable improvement in the pilot and copilot region, a slight improvement in the occupant model response, and an over-stiffening effect in the passenger region. One lesson learned was that this approach should be adopted early on, in combination with the building-block approaches that are customarily used, for model development and pretest predictions. Complete crash simulations with validated finite element models can be used to satisfy crash certification requirements, potentially reducing overall development costs.

Comparison of Test and Finite Element Analysis for Two Full-Scale Helicopter Crash Tests

NASA Technical Reports Server (NTRS)

Annett, Martin S.; Horta,Lucas G.

2011-01-01

Finite element analyses have been performed for two full-scale crash tests of an MD-500 helicopter. The first crash test was conducted to evaluate the performance of a composite deployable energy absorber under combined flight loads. In the second crash test, the energy absorber was removed to establish the baseline loads. The use of an energy absorbing device reduced the impact acceleration levels by a factor of three. Accelerations and kinematic data collected from the crash tests were compared to analytical results. Details of the full-scale crash tests and development of the system-integrated finite element model are briefly described along with direct comparisons of acceleration magnitudes and durations for the first full-scale crash test. Because load levels were significantly different between tests, models developed for the purposes of predicting the overall system response with external energy absorbers were not adequate under more severe conditions seen in the second crash test. Relative error comparisons were inadequate to guide model calibration. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used for the second full-scale crash test. The calibrated parameter set reduced 2-norm prediction error by 51% but did not improve impact shape orthogonality.

Large Field Photogrammetry Techniques in Aircraft and Spacecraft Impact Testing

NASA Technical Reports Server (NTRS)

Littell, Justin D.

2010-01-01

The Landing and Impact Research Facility (LandIR) at NASA Langley Research Center is a 240 ft. high A-frame structure which is used for full-scale crash testing of aircraft and rotorcraft vehicles. Because the LandIR provides a unique capability to introduce impact velocities in the forward and vertical directions, it is also serving as the facility for landing tests on full-scale and sub-scale Orion spacecraft mass simulators. Recently, a three-dimensional photogrammetry system was acquired to assist with the gathering of vehicle flight data before, throughout and after the impact. This data provides the basis for the post-test analysis and data reduction. Experimental setups for pendulum swing tests on vehicles having both forward and vertical velocities can extend to 50 x 50 x 50 foot cubes, while weather, vehicle geometry, and other constraints make each experimental setup unique to each test. This paper will discuss the specific calibration techniques for large fields of views, camera and lens selection, data processing, as well as best practice techniques learned from using the large field of view photogrammetry on a multitude of crash and landing test scenarios unique to the LandIR.

Impact tests on fibrous composite sandwich structures

NASA Technical Reports Server (NTRS)

Rhodes, M. D.

1978-01-01

The effect of low velocity impact on the strength of laminates fabricated from graphite/epoxy and Kevlar 49/epoxy composite materials was studied. The test laminates were loaded statically either in uniaxial tension or compression when impact occurred to evaluate the effect of loading on the initiation of damage and/or failure. Typical aircraft service conditions such as runway debris encountered during landing were simulated by impacting 1.27-cm-diameter projectiles normal to the plane of the test laminates at velocities between 5.2 and 48.8 m/s.

Mechanical impact tests of materials in oxygen effects of contamination. [Teflon, stainless steel, and aluminum

NASA Technical Reports Server (NTRS)

Ordin, P. M.

1980-01-01

The effect of contaminants on the mechanical impact sensitivity of Teflon, stainless steel, and aluminum in a high-pressure oxygen environment was investigated. Uncontaminated Teflon did not ignite under the test conditions. The liquid contaminants - cutting oil, motor lubricating oil, and toolmaker dye - caused Teflon to ignite. Raising the temperature lowered the impact energy required for ignition. Stainless steel was insensitive to ignition under the test conditions with the contaminants used. Aluminum appeared to react without contaminants under certain test conditions; however, contamination with cutting oil, motor lubricating oil, and toolmakers dye increased the sensitivity of aluminum to mechanical impact. The grit contaminants silicon dioxide and copper powder did not conclusively affect the sensitivity of aluminum.

Examining the Feasibility and Effect of Transitioning GED Tests to Computer

ERIC Educational Resources Information Center

Higgins, Jennifer; Patterson, Margaret Becker; Bozman, Martha; Katz, Michael

2010-01-01

This study examined the feasibility of administering GED Tests using a computer based testing system with embedded accessibility tools and the impact on test scores and test-taker experience when GED Tests are transitioned from paper to computer. Nineteen test centers across five states successfully installed the computer based testing program,…

Tests of the Giant Impact Hypothesis

NASA Technical Reports Server (NTRS)

Jones, J. H.

1998-01-01

The giant impact hypothesis has gained popularity as a means of explaining a volatile-depleted Moon that still has a chemical affinity to the Earth. As Taylor's Axiom decrees, the best models of lunar origin are testable, but this is difficult with the giant impact model. The energy associated with the impact would be sufficient to totally melt and partially vaporize the Earth. And this means that there should he no geological vestige of Barber times. Accordingly, it is important to devise tests that may be used to evaluate the giant impact hypothesis. Three such tests are discussed here. None of these is supportive of the giant impact model, but neither do they disprove it.

Impact behavior of filament wound graphite/epoxy fan blades

NASA Technical Reports Server (NTRS)

Bowles, K. J.

1978-01-01

The fabrication and impact tests of graphite/epoxy filament wound fan blades are discussed. Blades which were spin tested at tip speeds up to 305 meters per second retained their structural integrity. Two blades were each impacted with a 454 gram slice of a 908 gram simulated bird at a tip speed of 263 meters per second and impact angles of 22 and 32 deg. The impact tests were recorded with high-speed movie film. The blade which was impacted at 22 deg sustained some root delamination but remained intact. The 32 deg impact separated the blade from the root. No local damage other than leading edge debonding was observed for either blade. Results of a failure mode analysis are also discussed.

Psychosocial impact of prognostic genetic testing in the care of uveal melanoma patients: protocol of a controlled prospective clinical observational study.

PubMed

Erim, Yesim; Scheel, Jennifer; Breidenstein, Anja; Metz, Claudia Hd; Lohmann, Dietmar; Friederich, Hans-Christoph; Tagay, Sefik

2016-07-07

Uveal melanoma patients with a poor prognosis can be detected through genetic analysis of the tumor, which has a very high sensitivity. A large number of patients with uveal melanoma decide to receive information about their individual risk and therefore routine prognostic genetic testing is being carried out on a growing number of patients. It is obvious that a positive prediction for recidivism in the future will emotionally burden the respective patients, but research on the psychosocial impact of this innovative method is lacking. The aim of the current study is therefore to investigate the psychosocial impact (psychological distress and quality of life) of prognostic genetic testing in patients with uveal melanoma. This study is a non-randomized controlled prospective clinical observational trial. Subjects are patients with uveal melanoma, in whom genetic testing is possible. Patients who consent to genetic testing are allocated to the intervention group and patients who refuse genetic testing form the observational group. Both groups receive cancer therapy and psycho-oncological intervention when needed. The psychosocial impact of prognostic testing is investigated with the following variables: resilience, social support, fear of tumor progression, depression, general distress, cancer-specific and general health-related quality of life, attitude towards genetic testing, estimation of the perceived risk of metastasis, utilization and satisfaction with psycho-oncological crisis intervention, and sociodemographic data. Data are assessed preoperatively (at initial admission in the clinic) and postoperatively (at discharge from hospital after surgery, 6-12 weeks, 6 and 12 months after initial admission). Genetic test results are communicated 6-12 weeks after initial admission to the clinic. We created optimal conditions for investigation of the psychosocial impact of prognostic genetic testing. This study will provide information on the course of disease and psychosocial outcomes after prognostic genetic testing. We expect that empirical data from our study will give a scientific basis for medico-ethical considerations.

Crash Test of Three Cessna 172 Aircraft at NASA Langley Research Center's Landing and Impact Research Facility

NASA Technical Reports Server (NTRS)

Littell, Justin D.

2015-01-01

During the summer of 2015, three Cessna 172 aircraft were crash tested at the Landing and Impact Research Facility (LandIR) at NASA Langley Research Center (LaRC). The three tests simulated three different crash scenarios. The first simulated a flare-to-stall emergency or hard landing onto a rigid surface such as a road or runway, the second simulated a controlled flight into terrain with a nose down pitch on the aircraft, and the third simulated a controlled flight into terrain with an attempt to unsuccessfully recover the aircraft immediately prior to impact, resulting in a tail strike condition. An on-board data acquisition system captured 64 channels of airframe acceleration, along with acceleration and load in two onboard Hybrid II 50th percentile Anthropomorphic Test Devices, representing the pilot and co-pilot. Each test contained different airframe loading conditions and results show large differences in airframe performance. This paper presents test methods used to conduct the crash tests and will summarize the airframe results from the test series.

Impact of Acoustic Standing Waves on Structural Responses: Reverberant Acoustic Testing (RAT) vs. Direct Field Acoustic Testing (DFAT)

NASA Technical Reports Server (NTRS)

Kolaini, Ali R.; Doty, Benjamin; Chang, Zensheu

2012-01-01

Loudspeakers have been used for acoustic qualification of spacecraft, reflectors, solar panels, and other acoustically responsive structures for more than a decade. Limited measurements from some of the recent speaker tests used to qualify flight hardware have indicated significant spatial variation of the acoustic field within the test volume. Also structural responses have been reported to differ when similar tests were performed using reverberant chambers. To address the impact of non-uniform acoustic field on structural responses, a series of acoustic tests were performed using a flat panel and a 3-ft cylinder exposed to the field controlled by speakers and repeated in a reverberant chamber. The speaker testing was performed using multi-input-single-output (MISO) and multi-input-multi-output (MIMO) control schemes with and without the test articles. In this paper the spatial variation of the acoustic field due to acoustic standing waves and their impacts on the structural responses in RAT and DFAT (both using MISO and MIMO controls for DFAT) are discussed in some detail.

PMHS impact response in 3 m/s and 8 m/s nearside impacts with abdomen offset.

PubMed

Miller, Carl S; Madura, Nathaniel H; Schneider, Lawrence W; Klinich, Kathleen D; Reed, Matthew P; Rupp, Jonathan D

2013-11-01

Lateral impact tests were performed using seven male post-mortem human subjects (PMHS) to characterize the force-deflection response of contacted body regions, including the lower abdomen. All tests were performed using a dual-sled, side-impact test facility. A segmented impactor was mounted on a sled that was pneumatically accelerated into a second, initially stationary sled on which a subject was seated facing perpendicular to the direction of impact. Positions of impactor segments were adjusted for each subject so that forces applied to different anatomic regions, including thorax, abdomen, greater trochanter, iliac wing, and thigh, could be independently measured on each PMHS. The impactor contact surfaces were located in the same vertical plane, except that the abdomen plate was offset 5.1 cm towards the subject. The masses of the sleds and the force- deflection characteristics of the energy-absorbing interface material between the sleds were set to provide the impactor sled with a velocity profile that matched the average driver door velocity history produced in a series of side NCAP tests. Impactor padding was also selected so that average ATD pelvis and thorax responses from the same series of side NCAP tests were reproduced when the ATD used in these tests was impacted using the average door-velocity history. Each subject was first impacted on one side of the body using an initial impactor speed of 3 m/s. If a post-test CT scan and strain-gage data revealed two or fewer non-displaced rib fractures, then the PMHS was impacted on the contralateral side of the body at a speed of 8 m/s or 10 m/s. The results of tests in the 3 m/s and 8 m/s conditions were used to develop force-deflection response corridors for the abdomen, force history response corridors for the pelvis (iliac wing and greater trochanter), the midthigh, and the thorax. Response corridors for the lateral acceleration of the pelvis were also developed. Future work will compare side impact ATD responses to these response corridors.

Fall-to-Fall Testing versus Spring-to-Spring Testing: What Is the Impact on a Local Community's Chapter 1 Evaluation?

ERIC Educational Resources Information Center

Bushner, Diane E.

The impact of a decision by a local program under Chapter 1, the federally funded program of financial assistance to special educational needs of children, to test students fall-to-fall or spring-to-spring was studied. Students enrolled in a Chapter 1 reading program in 1988-89 were tested on a fall-to-spring basis, a spring-to-spring basis, and a…

Repeatability and uncertainty analyses of NASA/MSFC light gas gun test data

NASA Technical Reports Server (NTRS)

Schonberg, William P.; Cooper, David

1993-01-01

This Final Report presents an overview of the impact tests performed at NASA/MSFC in the time period 1985 to 1991 and the results of phenomena repeatability and data uncertainty studies performed using the information obtained from those tests. An analysis of the data from over 400 tests conducted between 1989 and 1991 was performed to generate a database to supplement the Hypervelocity Impact Damage Database developed under a previous effort.

H-60A/L Passenger Airbag Protection: Vertical and Horizontal Impact Tests

DTIC Science & Technology

2013-04-30

aft facing seating . While impact testing has been widely performed on ejection seats , only limited testing has been done on helicopter seating ...manikins with the LARD scaled to represent large occupants in the aerospace environment. LARD is also used by the Air Force and JSF in ejection seat ...for all rigid seat tests, resulting in no notable differences (manikin motion , manikin response) between the standard and airbag restraints. The

Application of subsize specimens in nuclear plant life extension

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

Rosinski, S.T.; Kumar, A.S.; Cannon, S.C.

1991-01-01

The US Department of Energy is sponsoring a research effort through Sandia National Laboratories and the University of Missour-Rolla to test a correlation for the upper shelf energy (USE) values obtained from the impact testing of subsize Charpy V-notch specimens to those obtained from the testing of full size samples. The program involves the impact testing of unirradiated and irradiated full, half, and third size Charpy V-notch specimens. To verify the applicability of the correlation on LWR materials unirradiated and irradiated full, half, and third size Charpy V-notch specimens of a commercial pressure vessel steel (ASTM A533 Grade B) willmore » be tested. This paper will provide details of the program and present results obtained from the application of the developed correlation methodology to the impact testing of the unirradiated full, half, and third size A533 Grade B Charpy V-notch specimens.« less

Application of subsize specimens in nuclear plant life extension

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

Rosinski, S.T.; Kumar, A.S.; Cannon, S.C.

1991-12-31

The US Department of Energy is sponsoring a research effort through Sandia National Laboratories and the University of Missour-Rolla to test a correlation for the upper shelf energy (USE) values obtained from the impact testing of subsize Charpy V-notch specimens to those obtained from the testing of full size samples. The program involves the impact testing of unirradiated and irradiated full, half, and third size Charpy V-notch specimens. To verify the applicability of the correlation on LWR materials unirradiated and irradiated full, half, and third size Charpy V-notch specimens of a commercial pressure vessel steel (ASTM A533 Grade B) willmore » be tested. This paper will provide details of the program and present results obtained from the application of the developed correlation methodology to the impact testing of the unirradiated full, half, and third size A533 Grade B Charpy V-notch specimens.« less

Performance Evaluation of Pressure Transducers for Water Impacts

NASA Technical Reports Server (NTRS)

Vassilakos, Gregory J.; Stegall, David E.; Treadway, Sean

2012-01-01

The Orion Multi-Purpose Crew Vehicle is being designed for water landings. In order to benchmark the ability of engineering tools to predict water landing loads, test programs are underway for scale model and full-scale water impacts. These test programs are predicated on the reliable measurement of impact pressure histories. Tests have been performed with a variety of pressure transducers from various manufacturers. Both piezoelectric and piezoresistive devices have been tested. Effects such as thermal shock, pinching of the transducer head, and flushness of the transducer mounting have been studied. Data acquisition issues such as sampling rate and anti-aliasing filtering also have been studied. The response of pressure transducers have been compared side-by-side on an impulse test rig and on a 20-inch diameter hemisphere dropped into a pool of water. The results have identified a range of viable configurations for pressure measurement dependent on the objectives of the test program.

Hypervelocity impact testing of cables

NASA Technical Reports Server (NTRS)

Jex, D. W.; Adkinson, A. B.; English, J. E.; Linebaugh, C. E.

1973-01-01

The physics and electrical results obtained from simulated micrometeoroid testing of certain Skylab cables are presented. The test procedure, electrical circuits, test equipment, and cable types utilized are also explained.

The Multidimensional Impact of Teachers on Students

ERIC Educational Resources Information Center

Pope, Nolan G.

2017-01-01

For decades, policymakers and researchers have used value-added models that rely solely on student test scores to measure teacher quality. However, since teaching ability is multidimensional, test-score value-added measures of teacher quality may not fully capture the impact of teachers on students. In this paper, we use test-score and…

Investigating the Dimensionality of Examinee Motivation across Instruction Conditions in Low-Stakes Testing Contexts

ERIC Educational Resources Information Center

Finney, Sara J.; Mathers, Catherine E.; Myers, Aaron J.

2016-01-01

Research investigating methods to influence examinee motivation during low-stakes assessment of student learning outcomes has involved manipulating test session instructions. The impact of instructions is often evaluated using a popular self-report measure of test-taking motivation. However, the impact of these manipulations on the psychometric…

The Impact of Cooperative Learning on Critical Thinking Test Scores of Associate's Degree Graduates in Southwest Virginia

ERIC Educational Resources Information Center

Hodges, James Gregory

2013-01-01

This study examined the impact that the teaching technique known as cooperative learning had on the changes between pre- and post-test scores on all sub-categories ("induction, deduction, analysis, evaluation, inference", and "total composite") associated with the "California Critical Thinking Skills Test" (CCTST) for…

77 FR 51528 - Notice of Public Hearings for the Draft Environmental Impact Statement for Outdoor Research...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-24

... Impact Statement for Outdoor Research, Development, Test and Evaluation Activities, Naval Surface Warfare..., development, test and evaluation (RDT&E) activities within the Potomac River Test Range (PRTR) complex... current, baseline RDT&E mission requirements for activities that have the potential to affect human health...

49 CFR 572.76 - Limbs assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... (3) Align the test probe specified in § 572.77(a) with the longitudinal center line of the femur force gauge, so that at impact, the probe's longitudinal center line coincides with the sensor's longitudinal center line within ±2 degrees. (4) Impact the knee with the test probe moving horizontally and...

49 CFR 572.76 - Limbs assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (3) Align the test probe specified in § 572.77(a) with the longitudinal center line of the femur force gauge, so that at impact, the probe's longitudinal center line coincides with the sensor's longitudinal center line within ±2 degrees. (4) Impact the knee with the test probe moving horizontally and...

49 CFR 572.76 - Limbs assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... (3) Align the test probe specified in § 572.77(a) with the longitudinal center line of the femur force gauge, so that at impact, the probe's longitudinal center line coincides with the sensor's longitudinal center line within ±2 degrees. (4) Impact the knee with the test probe moving horizontally and...

49 CFR 572.76 - Limbs assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... (3) Align the test probe specified in § 572.77(a) with the longitudinal center line of the femur force gauge, so that at impact, the probe's longitudinal center line coincides with the sensor's longitudinal center line within ±2 degrees. (4) Impact the knee with the test probe moving horizontally and...

49 CFR 572.72 - Head assembly and test procedure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... intersection of the head midsagittal plane and the transverse plane which is perpendicular to the Z axis of the... and midsagittal planes passing through this point. (3) Impact the head with the test probe so that at... in the dummy's midsagittal plane. (4) Guide the test probe during impact so that there is no...

Crashworthiness of light aircraft fuselage structures: A numerical and experimental investigation

NASA Technical Reports Server (NTRS)

Nanyaro, A. P.; Tennyson, R. C.; Hansen, J. S.

1984-01-01

The dynamic behavior of aircraft fuselage structures subject to various impact conditions was investigated. An analytical model was developed based on a self-consistent finite element (CFE) formulation utilizing shell, curved beam, and stringer type elements. Equations of motion were formulated and linearized (i.e., for small displacements), although material nonlinearity was retained to treat local plastic deformation. The equations were solved using the implicit Newmark-Beta method with a frontal solver routine. Stiffened aluminum fuselage models were also tested in free flight using the UTIAS pendulum crash test facility. Data were obtained on dynamic strains, g-loads, and transient deformations (using high speed photography in the latter case) during the impact process. Correlations between tests and predicted results are presented, together with computer graphics, based on the CFE model. These results include level and oblique angle impacts as well as the free-flight crash test. Comparisons with a hybrid, lumped mass finite element computer model demonstrate that the CFE formulation provides the test overall agreement with impact test data for comparable computing costs.

Elemental Water Impact Test: Phase 3 Plunge Depth of a 36-Inch Aluminum Tank Head

NASA Technical Reports Server (NTRS)

Vassilakos, Gregory J.

2014-01-01

Spacecraft are being designed based on LS-DYNA water landing simulations. The Elemental Water Impact Test (EWIT) series was undertaken to assess the accuracy of LS-DYNA water impact simulations. Phase 3 featured a composite tank head that was tested at a range of heights to verify the ability to predict structural failure of composites. To support planning for Phase 3, a test series was conducted with an aluminum tank head dropped from heights of 2, 6, 10, and 12 feet to verify that the test article would not impact the bottom of the test pool. This report focuses on the comparisons of the measured plunge depths to LS-DYNA predictions. The results for the tank head model demonstrated the following. 1. LS-DYNA provides accurate predictions for peak accelerations. 2. LS-DYNA consistently under-predicts plunge depth. An allowance of at least 20% should be added to the LS-DYNA predictions. 3. The LS-DYNA predictions for plunge depth are relatively insensitive to the fluid-structure coupling stiffness.

The NASA JSC Hypervelocity Impact Test Facility (HIT-F)

NASA Technical Reports Server (NTRS)

Crews, Jeanne L.; Christiansen, Eric L.

1992-01-01

The NASA Johnson Space Center Hypervelocity Impact Test Facility was created in 1980 to study the hypervelocity impact characteristics of composite materials. The facility consists of the Hypervelocity Impact Laboratory (HIRL) and the Hypervelocity Analysis Laboratory (HAL). The HIRL supports three different-size light-gas gun ranges which provide the capability of launching particle sizes from 100 micron spheres to 12.7 mm cylinders. The HAL performs three functions: (1) the analysis of data collected from shots in the HIRL, (2) numerical and analytical modeling to predict impact response beyond test conditions, and (3) risk and damage assessments for spacecraft exposed to the meteoroid and orbital debris environments.

Study on Mechanical Properties of Barite Concrete under Impact Load

NASA Astrophysics Data System (ADS)

Chen, Z. F.; Cheng, K.; Wu, D.; Gan, Y. C.; Tao, Q. W.

2018-03-01

In order to research the mechanical properties of Barite concrete under impact load, a group of concrete compression tests was carried out under the impact load by using the drop test machine. A high-speed camera was used to record the failure process of the specimen during the impact process. The test results show that:with the increase of drop height, the loading rate, the peak load, the strain under peak load, the strain rate and the dynamic increase factor (DIF) all increase gradually. The ultimate tensile strain is close to each other, and the time of impact force decreases significantly, showing significant strain rate effect.

Predicting multi-wall structural response to hypervelocity impact using the hull code

NASA Technical Reports Server (NTRS)

Schonberg, William P.

1993-01-01

Previously, multi-wall structures have been analyzed extensively, primarily through experiment, as a means of increasing the meteoroid/space debris impact protection of spacecraft. As structural configurations become more varied, the number of tests required to characterize their response increases dramatically. As an alternative to experimental testing, numerical modeling of high-speed impact phenomena is often being used to predict the response of a variety of structural systems under different impact loading conditions. The results of comparing experimental tests to Hull Hydrodynamic Computer Code predictions are reported. Also, the results of a numerical parametric study of multi-wall structural response to hypervelocity cylindrical projectile impact are presented.

Inhibited Shaped Charge Launcher Testing of Spacecraft Shield Designs

NASA Technical Reports Server (NTRS)

Grosch, Donald J.

1996-01-01

This report describes a test program in which several orbital debris shield designs were impact tested using the inhibited shaped charge launcher facility at Southwest Research Institute. This facility enables researchers to study the impact of one-gram aluminum projectiles on various shielding designs at velocities above 11 km/s. A total of twenty tests were conducted on targets provided by NASA-MSFC. This report discusses in detail the shield design, the projectile parameters and the test configuration used for each test. A brief discussion of the target damage is provided, as the detailed analysis of the target response will be done by NASA-MSFC.

Full-Scale Crash Test of a MD-500 Helicopter with Deployable Energy Absorbers

NASA Technical Reports Server (NTRS)

Kellas, Sotiris; Jackson, Karen E.; Littell, Justin D.

2010-01-01

A new externally deployable energy absorbing system was demonstrated during a full-scale crash test of an MD-500 helicopter. The deployable system is a honeycomb structure and utilizes composite materials in its construction. A set of two Deployable Energy Absorbers (DEAs) were fitted on the MD-500 helicopter for the full-scale crash demonstration. Four anthropomorphic dummy occupants were also used to assess human survivability. A demonstration test was performed at NASA Langley's Landing and Impact Research Facility (LandIR). The test involved impacting the helicopter on a concrete surface with combined forward and vertical velocity components of 40-ft/s and 26-ft/s, respectively. The objectives of the test were to evaluate the performance of the DEA concept under realistic crash conditions and to generate test data for validation of dynamic finite element simulations. Descriptions of this test as well as other component and full-scale tests leading to the helicopter test are discussed. Acceleration data from the anthropomorphic dummies showed that dynamic loads were successfully attenuated to within non-injurious levels. Moreover, the airframe itself survived the relatively severe impact and was retested to provide baseline data for comparison for cases with and without DEAs.

Impact test of a crash-energy management passenger rail car

DOT National Transportation Integrated Search

2004-04-06

On December 3, 2003, a single-car impact test was : conducted to assess the crashworthiness performance of a : modified passenger rail car. A coach car retrofitted with a : Crash Energy Management (CEM) end structure impacted a : fixed barrier at app...

A train-to-train impact test of crash energy management passenger rail equipment

DOT National Transportation Integrated Search

2006-12-04

This paper gives an overview of the in-line full-scale impact tests conducted by the Federal : Railroad Administration and discusses a strategy for preventing override between colliding : equipment. Override of the impacting equipment during a passen...

Impact testing of textile composite materials

NASA Technical Reports Server (NTRS)

Portanova, Marc

1995-01-01

The objectives of this report were to evaluate the impact damage resistance and damage tolerance of a variety of textile composite materials. Static indentation and impact tests were performed on the stitched and unstitched uniweave composites constructed from AS4/3501-6 Carbon/Epoxy with a fiberglass yarn woven in to hold the fibers together while being stitched. Compression and tension were measured after the tests to determine the damage resistance, residual strength and the damage tolerance of the specimens.

Impact Testing of Orbiter Thermal Protection System Materials

NASA Technical Reports Server (NTRS)

Kerr, Justin

2006-01-01

This viewgraph presentation reviews the impact testing of the materials used in designing the shuttle orbiter thermal protection system (TPS). Pursuant to the Columbia Accident Investigation Board recommendations a testing program of the TPS system was instituted. This involved using various types of impactors in different sizes shot from various sizes and strengths guns to impact the TPS tiles and the Leading Edge Structural Subsystem (LESS). The observed damage is shown, and the resultant lessons learned are reviewed.

Particle Impact Ignition Test Data on a Stainless Steel Hand Valve

NASA Technical Reports Server (NTRS)

Peralta, Stephen

2010-01-01

This slide presentation reviews the particle impact ignition test of a stainless steel hand valve. The impact of particles is a real fire hazard with stainless steel hand valves, however 100 mg of particulate can be tolerated. Since it is unlikely that 100 mg of stainless steel contaminant particles can be simultaneously released into this type of valve in the WSTF configuration, this is acceptable and within statistical confidence as demonstrated by testing.

Imparting Barely Visible Impact Damage to a Stitched Composite Large-Scale Pressure Box

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.; Przekop, Adam

2016-01-01

The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is a concept that was developed by The Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body (HWB) aircraft configuration, which has been a focus of the NASA Environmentally Responsible Aviation Project. The NASA-Boeing structural development for the HWB aircraft culminated in testing of the multi-bay box, which is an 80%-scale representation of the pressurized center-body section. This structure was tested in the NASA Langley Research Center Combined Loads Test System facility. As part of this testing, barely visible impact damage was imparted to the interior and exterior of the test article to demonstrate compliance with a condition representative of the requirements for Category 1 damaged composite structure as defined by the Federal Aviation Regulations. Interior impacts were imparted using an existing spring-loaded impactor, while the exterior impacts were imparted using a newly designed, gravity-driven impactor. This paper describes the impacts to the test article, and the design of the gravitydriven guided-weight impactor. The guided-weight impactor proved to be a very reliable method to impart barely visible impact damage in locations which are not easily accessible for a traditional drop-weight impactor, while at the same time having the capability to be highly configurable for use on other aircraft structures.

Determine ISS Soyuz Orbital Module Ballistic Limits for Steel Projectiles Hypervelocity Impact Testing

NASA Technical Reports Server (NTRS)

Lyons, Frankel

2013-01-01

A new orbital debris environment model (ORDEM 3.0) defines the density distribution of the debris environment in terms of the fraction of debris that are low-density (plastic), medium-density (aluminum) or high-density (steel) particles. This hypervelocity impact (HVI) program focused on assessing ballistic limits (BLs) for steel projectiles impacting the enhanced Soyuz Orbital Module (OM) micrometeoroid and orbital debris (MMOD) shield configuration. The ballistic limit was defined as the projectile size on the threshold of failure of the OM pressure shell as a function of impact speeds and angle. The enhanced OM shield configuration was first introduced with Soyuz 30S (launched in May 2012) to improve the MMOD protection of Soyuz vehicles docked to the International Space Station (ISS). This test program provides HVI data on U.S. materials similar in composition and density to the Russian materials for the enhanced Soyuz OM shield configuration of the vehicle. Data from this test program was used to update ballistic limit equations used in Soyuz OM penetration risk assessments. The objective of this hypervelocity impact test program was to determine the ballistic limit particle size for 440C stainless steel spherical projectiles on the Soyuz OM shielding at several impact conditions (velocity and angle combinations). This test report was prepared by NASA-JSC/ HVIT, upon completion of tests.

Design of Spacecraft Missions to Test Kinetic Impact for Asteroid Deflection

NASA Technical Reports Server (NTRS)

Barbee, Brent W.; Hernandez, Sonia

2012-01-01

Earth has previously been struck with devastating force by near-Earth asteroids (NEAs) and will be struck again. Telescopic search programs aim to provide advance warning of such an impact, but no techniques or systems have yet been tested for deflecting an incoming NEA. To begin addressing this problem, we have analyzed the more than 8000 currently known NEAs to identify those that offer opportunities for safe and meaningful near-term tests of the proposed kinetic impact asteroid deflection technique. In this paper we present our methodology and results, including complete mission designs for the best kinetic impactor test mission opportunities.

Characterization of Hypervelocity Impact Debris from the DebriSat Tests

NASA Astrophysics Data System (ADS)

Adams, P. M.; Sheaffer, P. M.; Lingley, Z.; Radhakrishnan, G.

The DebriSat program consisted of 3 hypervelocity impact tests conducted in 2 Torr of air with 7 km/s, 600 g aluminum projectiles. In the first test, Pre Preshot, the target consisted of multiple layers of fiberglass, stainless steel and Kevlar fabric. No soft catch foam was used. The subsequent two tests, DebrisLV and DebriSat, were designed to simulate hypervelocity impacts with a launch vehicle upper stage and a modern LEO satellite, respectively. The interior of the chamber was lined with soft catch foam to trap break-up fragments. In all three tests, witness plates were placed near the target to sample impact debris and determine its reflectance, composition and spectral properties. Reflectance measurements are important for calculating the size of orbital hypervelocity impact fragments. The debris from the Pre Preshot test consisted of a two-phase mixture formed from solidified molten silicate and steel droplets. Individual droplets ranged from 100 μm to 10 nm. The reflectance of witness plates dropped from 95% to 20-30% as a result of the debris. Debris collected on witness plates in the DebrisLV and DebriSat tests consisted of μm to nm-sized solidified molten metallic droplets in a matrix of condensed vaporized soft catch. Disordered graphitic carbon was also detected. The reflectance of debris-covered witness plates dropped from 95% to 5%. The dramatic decrease in reflectance for hypervelocity impact debris is attributed to the effect of scattering from μm to nm sized solidified molten metallic droplets and the presence of graphitic carbon, when organics are present. The presence of soft catch in the later tests and the high organic content with graphitic carbon in the debris appear to be responsible for this much lower post-test reflectance. Understanding orbital debris reflectance is critical for estimating size and determining debris detectability.

Materials Database Development for Ballistic Impact Modeling

NASA Technical Reports Server (NTRS)

Pereira, J. Michael

2007-01-01

A set of experimental data is being generated under the Fundamental Aeronautics Program Supersonics project to help create and validate accurate computational impact models of jet engine impact events. The data generated will include material property data generated at a range of different strain rates, from 1x10(exp -4)/sec to 5x10(exp 4)/sec, over a range of temperatures. In addition, carefully instrumented ballistic impact tests will be conducted on flat plates and curved structures to provide material and structural response information to help validate the computational models. The material property data and the ballistic impact data will be generated using materials from the same lot, as far as possible. It was found in preliminary testing that the surface finish of test specimens has an effect on measured high strain rate tension response of AL2024. Both the maximum stress and maximum elongation are greater on specimens with a smoother finish. This report gives an overview of the testing that is being conducted and presents results of preliminary testing of the surface finish study.

Hybrid carbon-glass fiber/toughened epoxy thick composites subject to drop-weight and ballistic impacts

NASA Astrophysics Data System (ADS)

Sevkat, Ercan

The goals of this study are to investigate the low velocity and ballistic impact response of thick-section hybrid fiber composites at room temperature. Plain-woven S2-Glass and IM7 Graphite fabrics are chosen as fiber materials reinforcing the SC-79 epoxy. Four different types of composites consisting of alternating layers of glass and graphite woven fabric sheets are considered. Tensile tests are conducted using 98 KN (22 kip) MTS testing machine equipped with environmental chamber. Low-velocity impact tests are conducted using an Instron-Dynatup 8250 impact test machine equipped with an environmental chamber. Ballistic impact tests are performed using helium pressured high-speed gas-gun. Tensile tests results were used to define the material behavior of the hybrid and non-hybrid composites in Finite Element modeling. The low velocity and ballistic impact tests showed that hybrid composites performance was somewhere between non-hybrid woven composites. Using woven glass fabrics as outer skin improved the impact performance of woven graphite composite. However hybrid composites are prone to delamination especially between dissimilar layers. The ballistic limit velocity V50 hybrid composites were higher that of woven graphite composite and lower than that of woven glass composite. Both destructive cross-sectional micrographs and nondestructive ultrasonic techniques are used to evaluate the damage created by impact. The Finite Element code LS-DYNA is chosen to perform numerical simulations of low velocity and ballistic impact on thick-section hybrid composites. The damage progression in these composites shows anisotropic nonlinearity. The material model to describe this behavior is not available in LS-DYNA material library. Initially, linear orthotropic material with damage (Chan-Chan Model) is employed to simulate some of the experimental results. Then, user-defined material subroutine is incorporated into LS-DYNA to simulate the nonlinear behavior. The experimentally obtained force-time histories, strain-time histories and damage patterns of impacted composites are compared with Finite element results. The results indicate that LS-DYNA could simulate the impact responses with sufficient accuracy once proper material models and boundary conditions are defined.

Composite Overwrapped Pressure Vessels: Database Extension Task 3.0 and Impact Damage Effects Control Task 8.0

NASA Technical Reports Server (NTRS)

Beeson, Harold D.; Davis, Dennis D.; Ross, William L., Sr.; Tapphorn, Ralph M.

2002-01-01

This document represents efforts accomplished at the NASA Johnson Space Center White Sands Test Facility (WSTF) in support of the Enhanced Technology for Composite Overwrapped Pressure Vessels (COPV) Program, a joint research and technology effort among the U.S. Air Force, NASA, and the Aerospace Corporation. WSTF performed testing for several facets of the program. Testing that contributed to the Task 3.0 COPV database extension objective included baseline structural strength, failure mode and safe-life, impact damage tolerance, sustained load/impact effect, and materials compatibility. WSTF was also responsible for establishing impact protection and control requirements under Task 8.0 of the program. This included developing a methodology for establishing an impact control plan. Seven test reports detail the work done at WSTF. As such, this document contributes to the database of information regarding COPV behavior that will ensure performance benefits and safety are maintained throughout vessel service life.

Hybrid composite laminates reinforced with Kevlar/carbon/glass woven fabrics for ballistic impact testing.

PubMed

Randjbaran, Elias; Zahari, Rizal; Jalil, Nawal Aswan Abdul; Majid, Dayang Laila Abang Abdul

2014-01-01

Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

Research on mechanical and sensoric set-up for high strain rate testing of high performance fibers

NASA Astrophysics Data System (ADS)

Unger, R.; Schegner, P.; Nocke, A.; Cherif, C.

2017-10-01

Within this research project, the tensile behavior of high performance fibers, such as carbon fibers, is investigated under high velocity loads. This contribution (paper) focuses on the clamp set-up of two testing machines. Based on a kinematic model, weight optimized clamps are designed and evaluated. By analyzing the complex dynamic behavior of conventional high velocity testing machines, it has been shown that the impact typically exhibits an elastic characteristic. This leads to barely predictable breaking speeds and will not work at higher speeds when acceleration force exceeds material specifications. Therefore, a plastic impact behavior has to be achieved, even at lower testing speeds. This type of impact behavior at lower speeds can be realized by means of some minor test set-up adaptions.

Occurrence of serious injury in real-world side impacts of vehicles with good side-impact protection ratings.

PubMed

Brumbelow, Matthew L; Mueller, Becky C; Arbelaez, Raul A

2015-01-01

The Insurance Institute for Highway Safety (IIHS) introduced its side impact consumer information test program in 2003. Since that time, side airbags and structural improvements have been implemented across the fleet and the proportion of good ratings has increased to 93% of 2012-2014 model year vehicles. Research has shown that drivers of good-rated vehicles are 70% less likely to die in a left-side crash than drivers of poor-rated vehicles. Despite these improvements, side impact fatalities accounted for about one quarter of passenger vehicle occupant fatalities in 2012. This study is a detailed analysis of real-world cases with serious injury resulting from side crashes of vehicles with good ratings in the IIHS side impact test. NASS-CDS and Crash Injury Research and Engineering Network (CIREN) were queried for occupants of good-rated vehicles who sustained an Abbreviated Injury Scale (AIS) ≥ 3 injury in a side-impact crash. The resulting 110 cases were categorized by impact configuration and other factors that contributed to injury. Patterns of impact configuration, restraint performance, and occupant injury were identified and discussed in the context of potential upgrades to the current IIHS side impact test. Three quarters of the injured occupants were involved in near-side impacts. For these occupants, the most common factors contributing to injury were crash severities greater than the IIHS test, inadequate side-airbag performance, and lack of side-airbag coverage for the injured body region. In the cases where an airbag was present but did not prevent the injury, occupants were often exposed to loading centered farther forward on the vehicle than in the IIHS test. Around 40% of the far-side occupants were injured from contact with the struck-side interior structure, and almost all of these cases were more severe than the IIHS test. The remaining far-side occupants were mostly elderly and sustained injury from the center console, instrument panel, or seat belt. In addition, many far-side occupants were likely out of position due to events preceding the side impact and/or being unbelted. Individual changes to the IIHS side impact test have the potential to reduce the number of serious injuries in real-world crashes. These include impacting the vehicle farther forward (relevant to 28% of all cases studied), greater test severity (17%), the inclusion of far-side occupants (9%), and more restrictive injury criteria (9%). Combinations of these changes could be more effective.

Test study on the performance of shielding configuration with stuffed layer under hypervelocity impact

NASA Astrophysics Data System (ADS)

Ke, Fa-wei; Huang, Jie; Wen, Xue-zhong; Ma, Zhao-xia; Liu, Sen

2016-10-01

In order to study the cracking and intercepting mechanism of stuffed layer configuration on the debris cloud and to develop stuffed layer configuration with better performance, the hypervelocity impact tests on shielding configurations with stuffed layer were carried out. Firstly, the hypervelocity impact tests on the shielding configuration with stuffed layer of 3 layer ceramic fibre and 3 layer aramid fibre were finished, the study results showed that the debris cloud generated by the aluminum sphere impacting bumper at the velocity of about 6.2 km/s would be racked and intercepted by the stuffed layer configuration efficiently when the ceramic fibre layers and aramid fibre layers were jointed together, however, the shielding performance would be declined when the ceramic fibre layers and aramid fibre layers were divided by some distance. The mechanism of stuffed layer racking and intercepting the debris cloud was analyzed according to the above test results. Secondly, based on the mechanism of the stuffed layer cracking and intercepint debirs cloud the hypervelocity impact tests on the following three stuffed layer structures with the equivalent areal density to the 1 mm-thick aluminum plate were also carried out to compare their performance of cracking and intercepting debris cloud. The mechanisms of stuffed layer racking and intercepting the debris cloud were validated by the test result. Thirdly, the influence of the stuffed layer position on the shielding performance was studied by the test, too. The test results would provide reference for the design of better performance shielding configuration with stuffed layer.

Groundwater Remediation and Alternate Energy at White Sands Test Facility

NASA Technical Reports Server (NTRS)

Fischer, Holger

2008-01-01

White Sands Test Facility Core Capabilities: a) Remote Hazardous Testing of Reactive, Explosive, and Toxic Materials and Fluids; b) Hypergolic Fluids Materials and Systems Testing; c) Oxygen Materials and System Testing; d) Hypervelocity Impact Testing; e)Flight Hardware Processing; and e) Propulsion Testing. There is no impact to any drinking water well. Includes public wells and the NASA supply well. There is no public exposure. Groundwater is several hundred feet below ground. No air or surface water exposure. Plume is moving very slowly to the west. Plume Front Treatment system will stop this westward movement. NASA performs on-going monitoring. More than 200 wells and zones are routinely sampled. Approx. 850 samples are obtained monthly and analyzed for over 300 different hazardous chemicals.

Side impact test and analyses of a DOT-111 tank car : final report.

DOT National Transportation Integrated Search

2015-10-01

Transportation Technology Center, Inc. conducted a side impact test on a DOT-111 tank car to evaluate the performance of the : tank car under dynamic impact conditions and to provide data for the verification and refinement of a computational model. ...

Impact tests of crash energy management passenger rail cars: analysis and structural measurements

DOT National Transportation Integrated Search

2004-11-13

Two full-scale impact tests were conducted to measure the : crashworthiness performance of Crash Energy Management : (CEM) passenger rail cars. On December 3, 2003 a single car : impacted a fixed barrier at approximately 35 mph and on : February 26, ...

Structural Behavior Under Precision Impact Tests

DTIC Science & Technology

1996-08-01

ASPECTS OF IMPACT TESTING The problem of impact between two bodies has been studied extensively (for example, Eibl 1987, Feyerabend 1988, Krauthammer...Concrete for Hazard Protection, Edinburgh, Scotland, pp. 175-186. Feyerabend , M., 1988, "Der harte Querstoss auf Stützen aus Stahl und Stahlbeton

Biomechanical Analysis of Military Boots. Phase 1. Materials Testing of Military and Commercial Footwear

DTIC Science & Technology

1992-10-01

N=8) and Results of 44 Statistical Analyses for Impact Test Performed on Forefoot of Unworn Footwear A-2. Summary Statistics (N=8) and Results of...on Forefoot of Worn Footwear Vlll Tables (continued) Table Page B-2. Summary Statistics (N=4) and Results of 76 Statistical Analyses for Impact...used tests to assess heel and forefoot shock absorption, upper and sole durability, and flexibility (Cavanagh, 1978). Later, the number of tests was

Effect of temperature on composite sandwich structures subjected to low velocity impact. [aircraft construction materials

NASA Technical Reports Server (NTRS)

Sharma, A. V.

1980-01-01

The effect of low velocity projectile impact on sandwich-type structural components was investigated. The materials used in the fabrication of the impact surface were graphite-, Kevlar-, and boron-fibers with appropriate epoxy matrices. The testing of the specimens was performed at moderately low- and high-temperatures as well as at room temperature to assess the impact-initiated strength degradation of the laminates. Eleven laminates with different stacking sequences, orientations, and thicknesses were tested. The low energy projectile impact is considered to simulate the damage caused by runway debris, the dropping of the hand tools during servicing, etc., on the secondary aircraft structures fabricated with the composite materials. The results show the preload and the impact energy combinations necessary to cause catastrophic failure in the laminates tested. A set of faired curves indicating the failure thresholds is shown separately for the tension-and compression-loaded laminates. The specific-strengths and -modulii for the various laminates tested are also given.

Impact-initiated damage thresholds in composites

NASA Technical Reports Server (NTRS)

Sharma, A. V.

1980-01-01

An experimental investigation was conducted to study the effect of low velocity projectile impact on the sandwich-type structural components. The materials used in the fabrication of the impact surface were graphite-, Kevlar-, and boron-fibers with appropriate epoxy matrices. The testing of the specimens was performed at moderately low- and high-temperatures as well as at room temperature to assess the impact-initiated strength degradation of the laminates. Eleven laminates with different stacking sequences, orientations, and thicknesses were tested. The low energy projectile impact is considered to simulate the damage caused by runway debris, dropping of the hand tools during servicing, etc., on the secondary aircraft structures fabricated with the composite materials. The results show the preload and the impact energy combinations necessary to cause catastrophic failures in the laminates tested. A set of faired curves indicating the failure thresholds is shown separately for the tension- and compression-loaded laminates. The specific-strengths and -moduli for the various laminates tested are also given.

Impact Test and Simulation of Energy Absorbing Concepts for Earth Entry Vehicles

NASA Technical Reports Server (NTRS)

Billings, Marcus D.; Fasanella, Edwin L.; Kellas, Sotiris

2001-01-01

Nonlinear dynamic finite element simulations have been performed to aid in the design of an energy absorbing concept for a highly reliable passive Earth Entry Vehicle (EEV) that will directly impact the Earth without a parachute. EEV's are designed to return materials from asteroids, comets, or planets for laboratory analysis on Earth. The EEV concept uses an energy absorbing cellular structure designed to contain and limit the acceleration of space exploration samples during Earth impact. The spherical shaped cellular structure is composed of solid hexagonal and pentagonal foam-filled cells with hybrid graphite- epoxy/Kevlar cell walls. Space samples fit inside a smaller sphere at the center of the EEV's cellular structure. Comparisons of analytical predictions using MSC,Dytran with test results obtained from impact tests performed at NASA Langley Research Center were made for three impact velocities ranging from 32 to 40 m/s. Acceleration and deformation results compared well with the test results. These finite element models will be useful for parametric studies of off-nominal impact conditions.

Comparison of Hard Surface and Soft Soil Impact Performance of a Crashworthy Composite Fuselage Concept

NASA Technical Reports Server (NTRS)

Sareen, Ashish K.; Sparks, Chad; Mullins, B. R., Jr.; Fasanella, Edwin; Jackson, Karen

2002-01-01

A comparison of the soft soil and hard surface impact performance of a crashworthy composite fuselage concept has been performed. Specifically, comparisons of the peak acceleration values, pulse duration, and onset rate at specific locations on the fuselage were evaluated. In a prior research program, the composite fuselage section was impacted at 25 feet per second onto concrete at the Impact Dynamics Research Facility (IDRF) at NASA Langley Research Center. A soft soil test was conducted at the same impact velocity as a part of the NRTC/RITA Crashworthy and Energy Absorbing Structures project. In addition to comparisons of soft soil and hard surface test results, an MSC. Dytran dynamic finite element model was developed to evaluate the test analysis correlation. In addition, modeling parameters and techniques affecting test analysis correlation are discussed. Once correlated, the analytical methodology will be used in follow-on work to evaluate the specific energy absorption of various subfloor concepts for improved crash protection during hard surface and soft soil impacts.

Hypervelocity Impact Testing of Nickel Hydrogen Battery Cells

NASA Technical Reports Server (NTRS)

Frate, David T.; Nahra, Henry K.

1996-01-01

Nickel-Hydrogen (Ni/H2) battery cells have been used on several satellites and are planned for use on the International Space Station. In January 1992, the NASA Lewis Research Center (LeRC) conducted hypervelocity impact testing on Ni/H2 cells to characterize their failure modes. The cell's outer construction was a 24 mil-thick Inconel 718 pressure vessel. A sheet of 1.27 cm thick honeycomb was placed in front of the battery cells during testing to simulate the on-orbit box enclosure. Testing was conducted at the NASA White Sands Test Facility (WSTF). The hypervelocity gun used was a 7.6 mm (0.30 caliber) two-stage light gas gun. Test were performed at speeds of 3, 6, and 7 km/sec using aluminum 2017 spherical particles of either 4.8 or 6.4 mm diameter as the projectile. The battery cells were electrically charged to about 75 percent of capacity, then back-filled with hydrogen gas to 900 psi simulating the full charge condition. High speed film at 10,000 frames/sec was taken of the impacts. Impacts in the dome area (top) and the electrode area (middle) of the battery cells were investigated. Five tests on battery cells were performed. The results revealed that in all of the test conditions investigated, the battery cells simply vented their hydrogen gas and some electrolyte, but did not burst or generate any large debris fragments.

Acoustic fatigue and sound transmission characteristics of a ram composite panel design

NASA Technical Reports Server (NTRS)

Cockburn, J. A.; Chang, K. Y.; Kao, G. C.

1972-01-01

An experimental study to determine the acoustic fatigue characteristics of a flat multi-layered structural panel is described. The test panel represented a proposed design for the outer skin of a research application module to be housed within the space shuttle orbiter vehicle. The test specimen was mounted in one wall of the Wyle 100,000 cu ft reverberation room and exposed to a broadband acoustic environment having an overall level of 145 db. The test panel was exposed to nine separate applications of the acoustic environment, each application consisting of 250 seconds duration. Upon completion of the ninth test run, the specimen was exposed to a simulated micrometeoroid impact near the panel center. One additional test run of 250 seconds duration was then performed to complete the overall simulation of 50 flight missions. The experimental results show that no significant fatigue damage occurred until the test specimen was exposed to a simulated micrometeoroid impact. The intermediate foam layer forming the core of the test specimen suffered considerable damage due to this impact, causing a marked variation in the dynamic characteristics of the overall test panel. During the final application of the acoustic environment, the strain and acceleration response spectra showed considerable variation from those spectra obtained prior to impact of the panel. Fatigue damage from acoustic loading however, was limited to partial de-bonding around the edges of the composite panel.

Experimental and numerical study of drill bit drop tests on Kuru granite.

PubMed

Fourmeau, Marion; Kane, Alexandre; Hokka, Mikko

2017-01-28

This paper presents an experimental and numerical study of Kuru grey granite impacted with a seven-buttons drill bit mounted on an instrumented drop test machine. The force versus displacement curves during the impact, so-called bit-rock interaction (BRI) curves, were obtained using strain gauge measurements for two levels of impact energy. Moreover, the volume of removed rock after each drop test was evaluated by stereo-lithography (three-dimensional surface reconstruction). A modified version of the Holmquist-Johnson-Cook (MHJC) material model was calibrated using Kuru granite test results available from the literature. Numerical simulations of the single drop tests were carried out using the MHJC model available in the LS-DYNA explicit finite-element solver. The influence of the impact energy and additional confining pressure on the BRI curves and the volume of the removed rock is discussed. In addition, the influence of the rock surface shape before impact was evaluated using two different mesh geometries: a flat surface and a hyperbolic surface. The experimental and numerical results are compared and discussed in terms of drilling efficiency through the mechanical specific energy.This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'. © 2016 The Author(s).

Experimental and numerical study of drill bit drop tests on Kuru granite

PubMed Central

Kane, Alexandre; Hokka, Mikko

2017-01-01

This paper presents an experimental and numerical study of Kuru grey granite impacted with a seven-buttons drill bit mounted on an instrumented drop test machine. The force versus displacement curves during the impact, so-called bit–rock interaction (BRI) curves, were obtained using strain gauge measurements for two levels of impact energy. Moreover, the volume of removed rock after each drop test was evaluated by stereo-lithography (three-dimensional surface reconstruction). A modified version of the Holmquist–Johnson–Cook (MHJC) material model was calibrated using Kuru granite test results available from the literature. Numerical simulations of the single drop tests were carried out using the MHJC model available in the LS-DYNA explicit finite-element solver. The influence of the impact energy and additional confining pressure on the BRI curves and the volume of the removed rock is discussed. In addition, the influence of the rock surface shape before impact was evaluated using two different mesh geometries: a flat surface and a hyperbolic surface. The experimental and numerical results are compared and discussed in terms of drilling efficiency through the mechanical specific energy. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’. PMID:27956511

Experimental stress analysis of large plastic deformations in a hollow sphere deformed by impact against a concrete block

NASA Technical Reports Server (NTRS)

Morris, R. E.

1973-01-01

An experimental plastic strain measurement system is presented for use on the surface of high velocity impact test models. The system was used on a hollow sphere tested in impact against a reinforced concrete block. True strains, deviatoric stresses, and true stresses were calculated from experimental measurements. The maximum strain measured in the model was small compared to the true failure strain obtained from static tensile tests of model material. This fact suggests that a much greater impact velocity would be required to cause failure of the model shell structure.

Out-of-plane properties

NASA Technical Reports Server (NTRS)

Jackson, Wade C.; Portanova, Marc A.

1995-01-01

This paper summarizes three areas of research which were performed to characterize out-of-plane properties of composite materials. In the first investigation, a series of tests was run to characterize the through-the-thickness tensile strength for a variety of composites that included 2D braids, 2D and 3D weaves, and prepreg tapes. A new test method based on a curved beam was evaluated. Failures were significantly different between the 2D materials and the 3D weaves. The 2D materials delaminated between layers due to out-of-plane tensile stresses while the 3D weaves failed due to the formation of radial cracks between the surface plies caused by high circumferential stresses along the inner radius. The strength of the 2D textile composites did not increase relative to the tapes. Final failure in the 3D weaves was caused by a circumferential crack similar to the 2D materials and occurred at a lower bending moment than in other materials. The early failures in the 3D weaves were caused by radial crack formation rather than a low through-the-thickness strength. The second investigation focused on the development of a standard impact test method to measure impact damage resistance. The only impact tests that currently exist are compression after impact (CAI) tests which incorporate elements of both damage resistance and damage tolerance. A new impact test method is under development which uses a quasi-static indentation (QSI) test to directly measure damage resistance. Damage resistance is quantified in terms of the contact force to produce a unit of damage where a metric for damage may be area in C-scan, depth of residual dent , penetration, damage growth, etc. A final draft of an impact standard that uses a QSI test method will be presented to the ASTM Impact Task Group on impact. In the third investigation, the impact damage resistance behavior of a variety of textile materials was studied using the QSI test method. In this study, the force where large damage initiates was measured and the delamination size as a function of force was determined. The force to initiate large damage was significantly lower in braids and weaves. The delamination diameter - impact forace relationship was quanitfied using a damage resistance parameter, Q(*), which related delamination diameter to imapct force over a range of delamination sizes. Using this Q(*) parameter to rate the materials, the stitched uniweaves, toughened epoxy tapes, and through-the-thickness orthogonal interlock weave were the most damage resistant.

49 CFR 572.180 - Incorporated materials.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES ES-2re Side Impact Crash... 50th Percentile Adult Male Side Impact Crash Test Dummy, February 2008,” incorporated by reference in...

49 CFR 572.180 - Incorporated materials.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES ES-2re Side Impact Crash... 50th Percentile Adult Male Side Impact Crash Test Dummy, February 2008,” incorporated by reference in...

Using TRAILS to Assess Student Learning: A Step-by-Step Guide

ERIC Educational Resources Information Center

Owen, Patricia L.

2010-01-01

School librarians nationwide seek to produce evidence of the library's impact on student learning and achievement. While classroom teachers demonstrate their impact through the use of standardized test scores including end-of-grade tests and SAT/ACT tests, school librarians have long used informal or in-class assessments to gauge student learning.…

The TOEFL Trump Card: An Investigation of Test Impact in an ESL Classroom

ERIC Educational Resources Information Center

Johnson, Karen E.; Jordan, Stefanie Rehn; Poehner, Matthew E.

2005-01-01

Much of the research on the effects of tests on foreign and second-language classrooms has examined the impact or washback effect that commercial/institutional language tests, such as the TOEFL, have on teachers' instructional practices (Hughes, 1998; Wall & Alderson, 1993). Using a case study methodology, this study uncovered the ways in…

Energetic Materials Center Report--Small-Scale Safety and Thermal Testing Evaluation of Butyl Nitrate

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

Hsu, Peter C.; Reynolds, John G.

2013-04-26

Butyl Nitrate (BN) was examined by Small-Scale Safety and Thermal (SSST) Testing techniques to determine its sensitivity to impact, friction, spark and thermal exposure simulating handling and storage conditions. Under the conditions tested, the BN exhibits thermal sensitivity above 150 °C, and does not exhibit sensitive to impact, friction or spark.

Testing Means-Tested Aid. CEP Discussion Paper No. 1396. Revised

ERIC Educational Resources Information Center

Murphy, Richard; Wyness, Gill

2016-01-01

Inequalities do not end once students enter higher education. Yet, the majority of papers on the effectiveness of higher education aid examine its impact on college enrolment. In this paper, we provide evidence on the causal impact of means-tested but otherwise unconditional financial aid on the outcomes of students who have already enrolled in…

Ethics Standards Impacting Test Development and Use: A Review of 31 Ethics Codes Impacting Practices in 35 Countries

ERIC Educational Resources Information Center

Leach, Mark M.; Oakland, Thomas

2007-01-01

Ethics codes are designed to protect the public by prescribing behaviors professionals are expected to exhibit. Although test use is universal, albeit reflecting strong Western influences, previous studies that examine the degree issues pertaining to test development and use and that are addressed in ethics codes of national psychological…

Urineschool: A Study of the Impact of the Earls Decision on High School Random Drug Testing Policies.

ERIC Educational Resources Information Center

Conlon, Cynthia Kelly

2003-01-01

Examines impact of Supreme Court's 2002 decision in "Board of Education v. Earls" on high school random drug-testing policies and practices. Court held that random drug-testing policy at Tecumseh, Oklahoma, school district did not violate students' Fourth Amendment right against unreasonable searches. (Contains 46 references.) (PKP)

49 CFR 572.116 - Instrumentation and test conditions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... probe for lateral thoracic and pelvis impact tests are the same as those specified in § 572.44(a). (b... pelvis is the same as specified in § 572.44(c). (d) Head accelerometer mounting is the same as specified... Impact Tests.” (g) The mountings for the spine, rib and pelvis accelerometers shall have no resonance...

49 CFR 572.116 - Instrumentation and test conditions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... probe for lateral thoracic and pelvis impact tests are the same as those specified in § 572.44(a). (b... pelvis is the same as specified in § 572.44(c). (d) Head accelerometer mounting is the same as specified... Impact Tests.” (g) The mountings for the spine, rib and pelvis accelerometers shall have no resonance...

49 CFR 572.116 - Instrumentation and test conditions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... probe for lateral thoracic and pelvis impact tests are the same as those specified in § 572.44(a). (b... pelvis is the same as specified in § 572.44(c). (d) Head accelerometer mounting is the same as specified... Impact Tests.” (g) The mountings for the spine, rib and pelvis accelerometers shall have no resonance...

49 CFR 572.116 - Instrumentation and test conditions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... probe for lateral thoracic and pelvis impact tests are the same as those specified in § 572.44(a). (b... pelvis is the same as specified in § 572.44(c). (d) Head accelerometer mounting is the same as specified... Impact Tests.” (g) The mountings for the spine, rib and pelvis accelerometers shall have no resonance...

49 CFR 572.116 - Instrumentation and test conditions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... probe for lateral thoracic and pelvis impact tests are the same as those specified in § 572.44(a). (b... pelvis is the same as specified in § 572.44(c). (d) Head accelerometer mounting is the same as specified... Impact Tests.” (g) The mountings for the spine, rib and pelvis accelerometers shall have no resonance...

The Impact of Time-Series Diagnostic Tests on the Writing Ability of Iranian EFL Learners

ERIC Educational Resources Information Center

Atashgahi, Bahareh Molazem

2014-01-01

This study aimed to show whether administering a battery of time-series diagnostic tests (screening) has any impact on Iranian EFL learners' writing ability. The study was conducted on the intermediate EFL learners at Islamic Azad University North Tehran branch. The researcher administered a homogenizing test in order to exclude the exceptional…

The Effect of Pretest Exercise on Baseline Computerized Neurocognitive Test Scores.

PubMed

Pawlukiewicz, Alec; Yengo-Kahn, Aaron M; Solomon, Gary

2017-10-01

Baseline neurocognitive assessment plays a critical role in return-to-play decision making following sport-related concussions. Prior studies have assessed the effect of a variety of modifying factors on neurocognitive baseline test scores. However, relatively little investigation has been conducted regarding the effect of pretest exercise on baseline testing. The aim of our investigation was to determine the effect of pretest exercise on baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) scores in adolescent and young adult athletes. We hypothesized that athletes undergoing self-reported strenuous exercise within 3 hours of baseline testing would perform more poorly on neurocognitive metrics and would report a greater number of symptoms than those who had not completed such exercise. Cross-sectional study; Level of evidence, 3. The ImPACT records of 18,245 adolescent and young adult athletes were retrospectively analyzed. After application of inclusion and exclusion criteria, participants were dichotomized into groups based on a positive (n = 664) or negative (n = 6609) self-reported history of strenuous exercise within 3 hours of the baseline test. Participants with a positive history of exercise were then randomly matched, based on age, sex, education level, concussion history, and hours of sleep prior to testing, on a 1:2 basis with individuals who had reported no pretest exercise. The baseline ImPACT composite scores of the 2 groups were then compared. Significant differences were observed for the ImPACT composite scores of verbal memory, visual memory, reaction time, and impulse control as well as for the total symptom score. No significant between-group difference was detected for the visual motor composite score. Furthermore, pretest exercise was associated with a significant increase in the overall frequency of invalid test results. Our results suggest a statistically significant difference in ImPACT composite scores between individuals who report strenuous exercise prior to baseline testing compared with those who do not. Since return-to-play decision making often involves documentation of return to neurocognitive baseline, the baseline test scores must be valid and accurate. As a result, we recommend standardization of baseline testing such that no strenuous exercise takes place 3 hours prior to test administration.

Impact behavior of filament-wound graphite/epoxy fan blades. [foreign object damage to turbofan engines

NASA Technical Reports Server (NTRS)

Bowles, K. J.

1978-01-01

The fabrication and impact tests of graphite/epoxy filament wound fan blades are discussed. Blades which were spin tested at tip speeds up to 305 m/sec retained their structural integrity. Two blades were each impacted with a 454-g slice of a 908-g simulated bird at a tip speed of 263 deg and impact angles of 22 deg and 32 deg. The impact tests were recorded with high-speed movie film. The blade which was impacted at 22 deg sustained some root delamination but remained intact. The 32 deg impact separated the blade from the root. No local damage other than leading-edge debonding was observed for either blade. The results of a failure mode analysis are also discussed.

Design and testing of an energy-absorbing crewseat for the F/FB-111 aircraft. Volume 3: Data from crew module testing

NASA Technical Reports Server (NTRS)

Shane, S. J.

1985-01-01

Over the past years, several papers and reports have documented the unacceptably high injury rate during the escape sequence (including the ejection and ground impact) of the crew module for F/FB-111 aircraft. This report documents a program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats. An energy absorbing test seat was designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions, was conducted at a sled test facility. Comparative tests with operational F-111 crewseats were also conducted. After successful dynamic testing of the seat, more testing was conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests werre conducted. The vertical drop tests were used to obtain comparative data between the energy absorbing and operational seats.

Comparing Free-Free and Shaker Table Model Correlation Methods Using Jim Beam

NASA Technical Reports Server (NTRS)

Ristow, James; Smith, Kenneth Wayne, Jr.; Johnson, Nathaniel; Kinney, Jackson

2018-01-01

Finite element model correlation as part of a spacecraft program has always been a challenge. For any NASA mission, the coupled system response of the spacecraft and launch vehicle can be determined analytically through a Coupled Loads Analysis (CLA), as it is not possible to test the spacecraft and launch vehicle coupled system before launch. The value of the CLA is highly dependent on the accuracy of the frequencies and mode shapes extracted from the spacecraft model. NASA standards require the spacecraft model used in the final Verification Loads Cycle to be correlated by either a modal test or by comparison of the model with Frequency Response Functions (FRFs) obtained during the environmental qualification test. Due to budgetary and time constraints, most programs opt to correlate the spacecraft dynamic model during the environmental qualification test, conducted on a large shaker table. For any model correlation effort, the key has always been finding a proper definition of the boundary conditions. This paper is a correlation case study to investigate the difference in responses of a simple structure using a free-free boundary, a fixed boundary on the shaker table, and a base-drive vibration test, all using identical instrumentation. The NAVCON Jim Beam test structure, featured in the IMAC round robin modal test of 2009, was selected as a simple, well recognized and well characterized structure to conduct this investigation. First, a free-free impact modal test of the Jim Beam was done as an experimental control. Second, the Jim Beam was mounted to a large 20,000 lbf shaker, and an impact modal test in this fixed configuration was conducted. Lastly, a vibration test of the Jim Beam was conducted on the shaker table. The free-free impact test, the fixed impact test, and the base-drive test were used to assess the effect of the shaker modes, evaluate the validity of fixed-base modeling assumptions, and compare final model correlation results between these boundary conditions.

16 CFR 1203.15 - Positional stability test (roll-off resistance).

Code of Federal Regulations, 2010 CFR

2010-01-01

... any slack. (3) Suspend the dynamic impact system from the helmet by positioning the flexible strap... positions. (3) Dynamic impact apparatus. A dynamic impact apparatus shall be used to apply a shock load to a helmet secured to the test headform. The dynamic impact apparatus shall allow a 4-kg (8.8-lb) drop weight...

Impact fracture toughness evaluation for high-density polyethylene materials

NASA Astrophysics Data System (ADS)

Cherief, M. N. D.; Elmeguenni, M.; Benguediab, M.

2017-03-01

The impact fracture behavior of a high-density polyethylene (HDPE) material is investigated experimentally and theoretically. Single-edge notched bending (SENB) specimens are tested in experiments with three-point bending and in the Charpy impact tests. An energy model is proposed for evaluating the HDPE impact toughness, which provides a description of both brittle and ductile fracture.

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2010 CFR

2010-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2011 CFR

2011-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2013 CFR

2013-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2014 CFR

2014-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2012 CFR

2012-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

Environmental effects on FOD resistance of composite fan blade

NASA Technical Reports Server (NTRS)

Murphy, G. C.; Selemme, C. T.

1981-01-01

The sensitivity of the impact characteristics of typical polymeric composite fan blade materials to potential limiting combinations of moisture, temperature level and temperature transients was established. The following four technical tasks are reported: (1) evaluation and characterization of constituent blade materials; (2) ballistic impact tests; (3) leading edge impact protection systems; and (4) simulated blade spin impact tests.

Room-Temperature Charpy Impact Property of 3D-Printed 15-5 Stainless Steel

NASA Astrophysics Data System (ADS)

Sagar, Sugrim; Zhang, Yi; Wu, Linmin; Park, Hye-Young; Lee, Je-Hyun; Jung, Yeon-Gil; Zhang, Jing

2018-01-01

In this study, the room-temperature Charpy impact property of 3D-printed 15-5 stainless steel was investigated by a combined experimental and finite element modeling approach. The experimentally measured impact energy is 10.85 ± 1.20 J/cm2, which is comparable to the conventionally wrought and non-heat treated 15-5 stainless steel. In parallel to the impact test experiment, a finite element model using the Johnson-Cook material model with damage parameters was developed to simulate the impact test. The simulated impact energy is 10.46 J/cm2, which is in good agreement with the experimental data. The fracture surface from the experimentally tested specimen suggests that the 3D-printed specimens undergo predominately brittle fracture.

Development of impact resistant boron/aluminum composites for turbojet engine fan blades

NASA Technical Reports Server (NTRS)

Melnyk, P.; Toth, I. J.

1975-01-01

Composite fabrication was performed by vacuum press diffusion bonding by both the foil-filament array and preconsolidated monotape methods. The effect of matrix material, fiber diameter, matrix enhancement, fiber volume reinforcement, test temperature, angle-plying, notch, impact orientation, processing variables and fabrication methods on tensile strength and Charpy impact resistance are evaluated. Root attachment concepts, were evaluated by room and elevated temperature tensile testing, as well as by pendulum-Izod and ballistic impact testing. Composite resistance to foreign object damage was also evaluated by ballistic impacting of panels using projectiles of gelatin, RTV rubber and steel at various velocities, and impingement angles. A significant improvement in the pendulum impact resistance of B-Al composites was achieved.

Test plan. Task 5, subtask 5.2: Early on-orbit TPSdebris impact tests

NASA Technical Reports Server (NTRS)

Greenberg, H. S.

1994-01-01

The limitation of damage to, and survival of, the cryogenic tankage during the on-orbit stay despite potential impact of orbital debris, may be a significant discriminator in the RHCTS trade studies described in the TA-1 trade study plan (ref. RHCTS-TSP-1) dated July 29, 1994. The objective of this early phase of an overall debris impact test program is to provide the data to support assessment of the relative suitability of integral and non integral tanks.

Design of Orion Soil Impact Study using the Modern Design of Experiments

NASA Technical Reports Server (NTRS)

DeLoach, Richard

2010-01-01

Two conventional One Factor At a Time (OFAT) test matrices under consideration for an Orion Landing System subscale soil impact study are reviewed. Certain weaknesses in the designs, systemic to OFAT experiment designs generally, are identified. An alternative test matrix is proposed that is based in the Modern Design of Experiments (MDOE), which achieves certain synergies by combining the original two test matrices into one. The attendant resource savings are quantified and the impact on uncertainty is discussed.

The impact of cognitive testing on the welfare of group housed primates.

PubMed

Whitehouse, Jamie; Micheletta, Jérôme; Powell, Lauren E; Bordier, Celia; Waller, Bridget M

2013-01-01

Providing cognitive challenges to zoo-housed animals may provide enriching effects and subsequently enhance their welfare. Primates may benefit most from such challenges as they often face complex problems in their natural environment and can be observed to seek problem solving opportunities in captivity. However, the extent to which welfare benefits can be achieved through programmes developed primarily for cognitive research is unknown. We tested the impact of voluntary participation cognitive testing on the welfare of a socially housed group of crested macaques (Macaca nigra) at the Macaque Study Centre (Marwell Zoo). First, we compared the rate of self-directed and social behaviours on testing and non-testing days, and between conditions within testing days. Minimal differences in behaviour were found when comparing testing and non-testing days, suggesting that there was no negative impact on welfare as a result of cognitive testing. Lipsmacking behaviours were found to increase and aggressive interaction was found to decrease in the group as a result of testing. Second, social network analysis was used to assess the effect of testing on associations and interactions between individuals. The social networks showed that testing subjects increased their association with others during testing days. One interpretation of this finding could be that providing socially housed primates with an opportunity for individuals to separate from the group for short periods could help mimic natural patterns of sub-group formation and reunion in captivity. The findings suggest, therefore, that the welfare of captive primates can be improved through the use of cognitive testing in zoo environments.

Impact of DNA testing for early-onset familial Alzheimer disease and frontotemporal dementia.

PubMed

Steinbart, E J; Smith, C O; Poorkaj, P; Bird, T D

2001-11-01

DNA testing of persons at risk for hereditary, degenerative neurologic diseases is relatively new. Only anecdotal reports of such testing in familial Alzheimer disease (FAD) exist, and little is know about the personal and social impact of such testing. In a descriptive, observational study, individuals at 50% risk for autosomal dominant, early-onset FAD or frontotemporal dementia with parkinsonism linked to chromosome 17 underwent DNA testing for the genetic mutations previously identified in affected family members. Individuals were followed up for (1/2) to 3 years and were interviewed regarding attitudes toward the testing process and the impact of the results. Twenty-one (8.4%) of 251 persons at risk for FAD or frontotemporal dementia requested genetic testing. The most common reasons for requesting testing were concern about early symptoms of dementia, financial or family planning, and relief from anxiety. Twelve individuals had positive DNA test results, and 6 of these had early symptoms of dementia; 8 had negative results; and 1 has not yet received results. Of 14 asymptomatic individuals completing testing, 13 believed the testing was beneficial. Two persons reported moderate anxiety and 1 reported moderate depression. As expected, persons with negative test results had happier experiences overall, but even they had to deal with ongoing anxiety and depression. Thus far, there have been no psychiatric hospitalizations, suicide attempts, or denials of insurance. Genetic testing in early-onset FAD and frontotemporal dementia can be completed successfully. Most individuals demonstrate effective coping skills and find the testing to be beneficial, but long-term effects remain unknown.

Humanising Language Testing

ERIC Educational Resources Information Center

Hamid, M. Obaidul; Hoang, Ngoc T. H.

2018-01-01

Test-takers' voices in relation to high-stakes language tests have received growing attention in recent years. While the perspectives of this stakeholder group can be utilised to improve test quality, test-taking experience, and test impact, we argue that this goal needs to be achieved by considering a fundamental shift in our conceptualisation of…

16 CFR 1203.13 - Test schedule.

Code of Federal Regulations, 2010 CFR

2010-01-01

... environments, respectively) shall be tested in accordance with the dynamic retention system strength test at... Peripheral vision § 1203.15 Positional stability § 1203.16 Retention system strength § 1203.17 Impact tests...

Design and testing of an energy-absorbing crewseat for the F/FB-111 aircraft. Volume 2: Data from seat testing

NASA Technical Reports Server (NTRS)

Shane, S. J.

1985-01-01

The unacceptably high injury rate during the escape sequence (including the ejection and ground impact) of the crew module for F/FB-111 aircraft is reviewed. A program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats is presented. An energy absorbing test seat is designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions is conducted at a sled test facility. Comparative tests with operational F-111 crewseats are also conducted. After successful dynamic testing of the seat, more testing is conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests are conducted. The vertical drop tests are used to obtain comparative data between the energy absorbing and operational seats. Volume 1 describes the energy absorbing test seat and testing conducted, and evaluates the data from both test series. Volume 2 presents the data obtained during the seat test series, while Volume 3 presents the data from the crew module test series.

Protective Skins for Composite Airliners

NASA Technical Reports Server (NTRS)

Johnson, Vicki S.; Boone, Richard L.; Jones, Shannon; Pendse, Vandana; Hayward, Greg

2014-01-01

Traditional composite aircraft structures are designed for load bearing and then overdesigned for impact damage and hot humid environments. Seeking revolutionary improvement in the performance and weight of composite structures, Cessna Aircraft Company, with sponsorship from the NASA Fundamental Aeronautics Program/Subsonic Fixed Wing Project, has developed and tested a protective skin concept which would allow the primary composite structure to carry only load and would meet the impact, hot and humid, and other requirements through protective skins. A key requirement for the protective skins is to make any impact damage requiring repair visible. Testing from the first generation of skins helped identify the most promising materials which were used in a second generation of test articles. This report summarizes lessons learned from the first generation of protective skins, the design and construction of the second-generation test articles, test results from the second generation for impact, electromagnetic effects, aesthetics and smoothing, thermal, and acoustic (for the first time), and an assessment of the feasibility of the protective skin concept.

Evaluation of seismic spatial interaction effects through an impact testing program

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

Thomas, B.D.; Driesen, G.E.

The consequences of non-seismically qualified objects falling and striking essential, seismically qualified objects is an analytically difficult problem to assess. Analytical solutions to impact problems are conservative and only available for simple situations. In a nuclear facility, the numerous ``sources`` and ``targets`` requiring evaluation often have complex geometric configurations, which makes calculations and computer modeling difficult. Few industry or regulatory rules are available for this specialized assessment. A drop test program was recently conducted to ``calibrate`` the judgment of seismic qualification engineers who perform interaction evaluations and to further develop seismic interaction criteria. Impact tests on varying combinations of sourcesmore » and targets were performed by dropping the sources from various heights onto targets that were connected to instruments. This paper summarizes the scope, test configurations, and some results of the drop test program. Force and acceleration time history data and general observations are presented on the ruggedness of various targets when subjected to impacts from different types of sources.« less

Evaluation of seismic spatial interaction effects through an impact testing program

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

Thomas, B.D.; Driesen, G.E.

The consequences of non-seismically qualified objects falling and striking essential, seismically qualified objects is an analytically difficult problem to assess. Analytical solutions to impact problems are conservative and only available for simple situations. In a nuclear facility, the numerous sources'' and targets'' requiring evaluation often have complex geometric configurations, which makes calculations and computer modeling difficult. Few industry or regulatory rules are available for this specialized assessment. A drop test program was recently conducted to calibrate'' the judgment of seismic qualification engineers who perform interaction evaluations and to further develop seismic interaction criteria. Impact tests on varying combinations of sourcesmore » and targets were performed by dropping the sources from various heights onto targets that were connected to instruments. This paper summarizes the scope, test configurations, and some results of the drop test program. Force and acceleration time history data and general observations are presented on the ruggedness of various targets when subjected to impacts from different types of sources.« less

Crash simulation of UNS electric vehicle under frontal front impact

NASA Astrophysics Data System (ADS)

Susilo, D. D.; Lukamana, N. I.; Budiana, E. P.; Tjahjana, D. D. D. P.

2016-03-01

Sebelas Maret University has been developing an Electric Vehicle namely SmarT-EV UNS. The main structure of the car are chasis and body. The chasis is made from steel and the body is made from fiberglass composite. To ensure the safety of the car, both static and dynamic tests were carried out to these structures, including their materials, like: tensile test, bending test, and impact test. Another test needed by this vehicle is crashworthiness test. To perform the test, it is needed complex equipments and it is quite expensive. Another way to obtain vehicle crashworthiness behaviour is by simulate it. The purpose of this study was to simulate the response of the Smart-EV UNS electric vehicle main structure when crashing rigid barrier from the front. The crash simulation was done in according to the NHTSA (National Highway Traffic Safety Administration) within the speed of the vehicle of 35 mph. The UNS Electric Vehicle was modelled using SolidWorks software, and the simulation process was done by finite element method using ANSYS software. The simulation result showed that the most internal impact energy was absorbed by chassis part. It absorbed 76.2% of impact energy, then the base absorbed 11.3 %, while the front body absorbed 2.5 %, and the rest was absorbed by fender, hood, and other parts.

Simulating the Impact Response of Full-Scale Composite Airframe Structures

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Jackson, Karen E.; Littell, Justin D.; Seal, Michael D.

2012-01-01

NASA Langley Research Center obtained a composite helicopter cabin structure in 2010 from the US Army's Survivable Affordable Repairable Airframe Program (SARAP) that was fabricated by Sikorsky Aircraft Corporation. The cabin had been subjected to a vertical drop test in 2008 to evaluate a tilting roof concept to limit the intrusion of overhead masses into the fuselage cabin. Damage to the cabin test article was limited primarily to the roof. Consequently, the roof area was removed and the remaining structure was cut into test specimens including a large subfloor section and a forward framed fuselage section. In 2011, NASA and Sikorsky entered into a cooperative research agreement to study the impact responses of composite airframe structures and to evaluate the capabilities of the explicit transient dynamic finite element code, LS-DYNA®, to simulate these responses including damage initiation and progressive failure. Most of the test articles were manufactured of graphite unidirectional tape composite with a thermoplastic resin system. However, the framed fuselage section was constructed primarily of a plain weave graphite fabric material with a thermoset resin system. Test data were collected from accelerometers and full-field photogrammetry. The focus of this paper will be to document impact testing and simulation results for the longitudinal impact of the subfloor section and the vertical drop test of the forward framed fuselage section.

Effect of Oxygen Concentration on Autogenous Ignition Temperature and Pneumatic Impact Ignitability of Nonmetallic Materials

NASA Technical Reports Server (NTRS)

Smith, Sarah

2009-01-01

Extensive test data exist on the ignitability of nonmetallic materials in pure oxygen, but these characteristics are not as well understood for lesser oxygen concentrations. In this study, autogenous ignition temperature testing and pneumatic impact testing were used to better understand the effects of oxygen concentration on ignition of nonmetallic materials. Tests were performed using oxygen concentrations of 21, 34, 45, and 100 %. The following materials were tested: PTFE Teflon(Registered Trademark), Buna-N, Silicone, Zytel(Registered Trademark) 42, Viton(registered Trademark) A, and Vespel(Registered Trademark) SP-21.

Side impact test and analysis of a DOT-112 tank car.

DOT National Transportation Integrated Search

2016-12-01

As part of a program to improve transportation safety for tank cars, Transportation Technology Center, Inc. (TTCI) has conducted a side impact test on a DOT-112 tank car to evaluate the performance of the DOT-112 under dynamic impact conditions and t...

Analysis of accelerations measured during full-scale tank car impact tests

DOT National Transportation Integrated Search

2007-04-01

Tank car impact responses were investigated using accelerometers mounted at various locations on a tank car. Several tests were run with both a full and an empty tank car, and varying the tank car impact speed. The data from the accelerometers went t...

Preparations for a train-to-train impact test of crash-energy management passenger rail equipment

DOT National Transportation Integrated Search

2005-03-16

Preparations are ongoing for a full-scale train-to-train : impact test of crash-energy management (CEM) equipment, : during which a cab car-led passenger consist, initially moving : at 30 mph, will impact a standing locomotive-led consist. The : coll...

Ballistic impact velocity response of carbon fibre reinforced aluminium alloy laminates for aero-engine

NASA Astrophysics Data System (ADS)

Mohammed, I.; Abu Talib, A. R.; Sultan, M. T. H.; Saadon, S.

2017-12-01

Aerospace and other industries use fibre metal laminate composites extensively due to their high specific strength, stiffness and fire resistance, in addition to their capability to be tailored into different forms for specific purposes. The behaviours of such composites under impact loading is another factor to be considered due to the impacts that occur in take-off, landing, during maintenance and operations. The aim of the study is to determine the specific perforation energy and impact strength of the fibre metal laminates of different layering pattern of carbon fibre reinforced aluminium alloy and hybrid laminate composites of carbon fibre and natural fibres (kenaf and flax). The composites are fabricated using the hand lay-up method in a mould with high bonding polymer matrix and compressed by a compression machine, cured at room temperature for one day and post cure in an oven for three hours. The impact tests are conducted using a gun tunnel system with a flat cylindrical bullet fired using a helium gas at a distance of 14 inches to the target. Impact and residual velocity of the projectile are recorded by high speed video camera. Specific perforation energy of carbon fibre reinforced aluminium alloy (CF+AA) for both before and after fire test are higher than the specific perforation energy of the other composites considered before and after fire test respectively. CF +AA before fire test is 55.18% greater than after. The same thing applies to impact strength of the composites where CF +AA before the fire test has the highest percentage of 11.7%, 50.0% and 32.98% as respectively compared to carbon fibre reinforced aluminium alloy (CARALL), carbon fibre reinforced flax aluminium alloy (CAFRALL) and carbon fibre reinforced kenaf aluminium alloy (CAKRALL), and likewise for the composites after fire test. The considered composites in this test can be used in the designated fire zone of an aircraft engine to protect external debris from penetrating the engine shield due to higher values of impact strength and specific perforation energy as highlighted by the test results.

Simulated Waste Testing Of Glycolate Impacts On The 2H-Evaporator System

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

Martino, C. J.

2013-08-13

Glycolic acid is being studied as a total or partial replacement for formic acid in the Defense Waste Processing Facility (DWPF) feed preparation process. After implementation, the recycle stream from DWPF back to the high-level waste tank farm will contain soluble sodium glycolate. Most of the potential impacts of glycolate in the tank farm were addressed via a literature review, but several outstanding issues remained. This report documents the non-radioactive simulant tests impacts of glycolate on storage and evaporation of Savannah River Site high-level waste. The testing for which non-radioactive simulants could be used involved the following: the partitioning ofmore » glycolate into the evaporator condensate, the impacts of glycolate on metal solubility, and the impacts of glycolate on the formation and dissolution of sodium aluminosilicate scale within the evaporator. The following are among the conclusions from this work: Evaporator condensate did not contain appreciable amounts of glycolate anion. Of all tests, the highest glycolate concentration in the evaporator condensate was 0.38 mg/L. A significant portion of the tests had glycolate concentration in the condensate at less than the limit of quantification (0.1 mg/L). At ambient conditions, evaporator testing did not show significant effects of glycolate on the soluble components in the evaporator concentrates. Testing with sodalite solids and silicon containing solutions did not show significant effects of glycolate on sodium aluminosilicate formation or dissolution.« less

Introducing National Tests in Swedish Primary Education: Implications for Test Anxiety

ERIC Educational Resources Information Center

Nyroos, Mikaela; Wiklund-Hornqvist, Carola

2011-01-01

Introduction: The Swedish government has decided to introduce national tests in primary education. Swedish pupils in general have few tests and a recognised possible adverse effect of testing is test anxiety among pupils, which may have a negative impact on examination performance. However, there has been little research on effects of testing on…

Free Recall Enhances Subsequent Learning

PubMed Central

Arnold, Kathleen M.; McDermott, Kathleen B.

2013-01-01

Testing, or retrieval practice, has become a central topic in memory research. One potentially important effect of retrieval practice has received little attention, however: Retrieval practice may enhance, or potentiate, subsequent learning. We introduce a paradigm that can measure the indirect, potentiating effect of free recall tests on subsequent learning, and then test a hypothesis for why tests have this potentiating effect. In two experiments, the benefit of a restudy trial was enhanced when prior free recall tests had been taken. Results from a third correlational study suggest that this effect may be mediated by the effect of testing on organization. Not only do encoding conditions impact later retrievability, but also retrieval attempts impact subsequent encoding effectiveness. PMID:23297100

The Impact of Human Capital on the Cost of Air Force Acquisition Programs

DTIC Science & Technology

2007-03-01

inspection as well as an empirical test of the data. To empirically test for heteroskedasticty, the Breusch - Pagan /Cook-Weisberg test was used. With a p...19 Pre-Specification Tests ......................................................................................................20 Post...Specification Tests .....................................................................................................22 Regression Results

Matter-Radiation Interactions in Extremes

Science.gov Websites

to resolve this capability gap. An experimental explosive is shown igniting during small-scale impact testing. An experimental explosive is shown igniting during small-scale impact testing. Accelerating in to

Teaching Grammar and Testing Grammar in the English Primary School: The Impact on Teachers and Their Teaching of the Grammar Element of the Statutory Test in Spelling, Punctuation and Grammar (SPaG)

ERIC Educational Resources Information Center

Safford, Kimberly

2016-01-01

The research examined the impact on teachers of the grammar element of a new statutory test in Spelling, Punctuation and Grammar (SPaG) in primary schools in England. The research aimed to evaluate the nature and the extent of changes to the teaching of grammar and to wider literacy teaching since the introduction of the test in 2013. The research…

Impact of Salt Waste Processing Facility Streams on the Nitric-Glycolic Flowsheet in the Chemical Processing Cell

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

Martino, C.

An evaluation of the previous Chemical Processing Cell (CPC) testing was performed to determine whether the planned concurrent operation, or “coupled” operations, of the Defense Waste Processing Facility (DWPF) with the Salt Waste Processing Facility (SWPF) has been adequately covered. Tests with the nitricglycolic acid flowsheet, which were both coupled and uncoupled with salt waste streams, included several tests that required extended boiling times. This report provides the evaluation of previous testing and the testing recommendation requested by Savannah River Remediation. The focus of the evaluation was impact on flammability in CPC vessels (i.e., hydrogen generation rate, SWPF solvent components,more » antifoam degradation products) and processing impacts (i.e., acid window, melter feed target, rheological properties, antifoam requirements, and chemical composition).« less

Development and Evaluation of Stitched Sandwich Panels

NASA Technical Reports Server (NTRS)

Stanley, Larry E.; Adams, Daniel O.; Reeder, James R. (Technical Monitor)

2001-01-01

This study explored the feasibility and potential benefits provided by the addition of through-the-thickness reinforcement to sandwich structures. Through-the-thickness stitching is proposed to increase the interlaminar strength and damage tolerance of composite sandwich structures. A low-cost, out-of-autoclave processing method was developed to produce composite sandwich panels with carbon fiber face sheets, a closed-cell foam core, and through-the-thickness Kevlar stitching. The sandwich panels were stitched in a dry preform state, vacuum bagged, and infiltrated using Vacuum Assisted Resin Transfer Molding (VARTM) processing. For comparison purposes, unstitched sandwich panels were produced using the same materials and manufacturing methodology. Test panels were produced initially at the University of Utah and later at NASA Langley Research Center. Four types of mechanical tests were performed: flexural testing, flatwise tensile testing, core shear testing, and edgewise compression testing. Drop-weight impact testing followed by specimen sectioning was performed to characterize the damage resistance of stitched sandwich panels. Compression after impact (CAI) testing was performed to evaluate the damage tolerance of the sandwich panels. Results show significant increases in the flexural stiffness and strength, out-of-plane tensile strength, core shear strength, edgewise compression strength, and compression-after-impact strength of stitched sandwich structures.

Is maternal plasma DNA testing impacting serum-based screening for aneuploidy in the United States?

PubMed

Palomaki, Glenn E; Ashwood, Edward R; Best, Robert G; Lambert-Messerlian, Geralyn; Knight, George J

2015-11-01

We sought to determine whether tests for fetal aneuploidy based on next-generation sequencing of cell-free DNA in maternal circulation have had an impact on routine serum-based screening in the general pregnant population. We compared results from laboratory surveys in 2011 and 2014 that reported types of prenatal serum screening tests and numbers of tests performed. Testing records from two prenatal serum screening laboratories examined temporal trends in the proportion of screened women 35 years of age and older from 2008 (or 2009) to 2014. The 82 laboratory survey results available for comparison showed that 1.7 million women were screened in 2014, a 5% increase over 2011. In the two screening laboratories, the proportion of screened women age 35 and older increased for several years but then experienced reductions of 8 and 18% by mid-2014 when compared with the highest rates observed. As of 2014, maternal plasma DNA testing appears to have had only a minor impact on serum screening rates in the United States. Ongoing surveillance has the potential to determine if, and when, DNA testing begins to replace serum testing as a primary screen for Down syndrome in the United States.

Hypervelocity impact testing of the Space Station utility distribution system carrier

NASA Technical Reports Server (NTRS)

Lazaroff, Scott

1993-01-01

A two-phase, joint JSC and McDonnell Douglas Aerospace-Huntington Beach hypervelocity impact (HVI) test program was initiated to develop an improved understanding of how meteoroid and orbital debris (M/OD) impacts affect the Space Station Freedom (SSF) avionic and fluid lines routed in the Utility Distribution System (UDS) carrier. This report documents the first phase of the test program which covers nonpowered avionic line segment and pressurized fluid line segment HVI testing. From these tests, a better estimation of avionic line failures is approximately 15 failures per year and could very well drop to around 1 or 2 avionic line failures per year (depending upon the results of the second phase testing of the powered avionic line at White Sands). For the fluid lines, the initial McDonnell Douglas analysis calculated 1 to 2 line failures over a 30 year period. The data obtained from these tests indicate the number of predicted fluid line failures increased slightly to as many as 3 in the first 10 years and up to 15 for the entire 30 year life of SSF.

14 CFR 35.36 - Bird impact.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird impact. 35.36 Section 35.36... STANDARDS: PROPELLERS Tests and Inspections § 35.36 Bird impact. The applicant must demonstrate, by tests or... 4-pound bird at the critical location(s) and critical flight condition(s) of a typical installation...

14 CFR 35.36 - Bird impact.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Bird impact. 35.36 Section 35.36... STANDARDS: PROPELLERS Tests and Inspections § 35.36 Bird impact. The applicant must demonstrate, by tests or... 4-pound bird at the critical location(s) and critical flight condition(s) of a typical installation...

Impacts Assessment of Dynamic Speed Harmonization with Queue Warning: Task 2 Impact Assessment Plan - Final

DOT National Transportation Integrated Search

2015-02-01

The purpose of the Impact Assessment Plan is to take the results of the test track or field tests of the prototype, make reasonable extrapolations of those results to a theoretical full scale implementation, and answer the following 7 questions relat...

Evaluation and comparison of transverse and impact strength of different high strength denture base resins.

PubMed

Gupta, Abhinav; Tewari, R K

2016-01-01

The present study was undertaken to evaluate and compare the impact strength and transverse strength of the high-impact denture base materials. A conventional heat polymerized acrylic resin was used as a control. The entire experiment was divided into four main groups with twenty specimens each according to denture base material selected Trevalon, Trevalon Hi, DPI Tuff and Metrocryl Hi. These groups were further subgrouped into the two parameters selected, impact strength and flexural strength with ten specimens each. These specimens were then subjected to transverse bend tests with the help of Lloyds instrument using a three point bend principle. Impact tests were undertaken using an Izod-Charpy digital impact tester. This study was analyzed with one-way analysis of variance using Fisher f-test and Bonferroni t-test. There was a significant improvement in the impact strength of high-impact denture base resins as compared to control (Trevalon). However, in terms of transverse bend tests, only DPI Tuff showed higher transverse strength in comparison to control. Trevalon Hi and Metrocryl Hi showed a decrease in transverse strength. Within the limits of this in vitro study, (1) There is a definite increase in impact strength due to the incorporation of butadiene styrene rubber in this high strength denture base materials as compared to Trevalon used as a control. (2) Further investigations are required to prevent the unduly decrease of transverse strength. (3) It was the limitation of the study that the exact composition of the high-impact resins was not disclosed by the manufacturer that would have helped in better understanding of their behavior.

Impact and fracture analysis of fish scales from Arapaima gigas.

PubMed

Torres, F G; Malásquez, M; Troncoso, O P

2015-06-01

Fish scales from the Amazonian fish Arapaima gigas have been characterised to study their impact and fracture behaviour at three different environmental conditions. Scales were cut in two different directions to analyse the influence of the orientation of collagen layers. The energy absorbed during impact tests was measured for each sample and SEM images were taken after each test in order to analyse the failure mechanisms. The results showed that scales tested at cryogenic temperatures display fragile behaviour, while scales tested at room temperature did not fracture. Different failure mechanisms have been identified, analysed and compared with the failure modes that occur in bone. The impact energy obtained for fish scales was two to three times higher than the values reported for bone in the literature. Copyright © 2015 Elsevier B.V. All rights reserved.

Scoring Method of a Situational Judgment Test: Influence on Internal Consistency Reliability, Adverse Impact and Correlation with Personality?

ERIC Educational Resources Information Center

De Leng, W. E.; Stegers-Jager, K. M.; Husbands, A.; Dowell, J. S.; Born, M. Ph.; Themmen, A. P.

2017-01-01

Situational Judgment Tests (SJTs) are increasingly used for medical school selection. Scoring an SJT is more complicated than scoring a knowledge test, because there are no objectively correct answers. The scoring method of an SJT may influence the construct and concurrent validity and the adverse impact with respect to non-traditional students.…

An Exploration of the Impact of Accountability Testing on Teaching in Urban Elementary Classrooms

ERIC Educational Resources Information Center

Bisland, Beverly Milner

2015-01-01

This study explores accountability testing in the elementary schools of New York City with particular emphasis on the impact of a statewide social studies test on the value given to social studies instruction in comparison to other subjects. The attitudes of a group of elementary teachers are examined. Some of the teachers taught all subjects in…

The Impact of Linking Distinct Achievement Test Scores on the Interpretation of Student Growth in Achievement

ERIC Educational Resources Information Center

Airola, Denise Tobin

2011-01-01

Changes to state tests impact the ability of State Education Agencies (SEAs) to monitor change in performance over time. The purpose of this study was to evaluate the Standardized Performance Growth Index (PGIz), a proposed statistical model for measuring change in student and school performance, across transitions in tests. The PGIz is a…

Dose prediction in Japan for nuclear test explosions in North Korea.

PubMed

Takada, Jun

2008-11-01

The impact on Japan of the underground test conducted in North Korea on October 9, 2006 is examined. By the use of the results of modelling assessment and environmental monitoring, it is concluded that there was no radiation impact on Japan. This suggests a safely conducted underground nuclear test or an explosion with a very low output.

Simulation of an Impact Test of the All-Composite Lear Fan Aircraft

NASA Technical Reports Server (NTRS)

Stockwell, Alan E.; Jones, Lisa E. (Technical Monitor)

2002-01-01

An MSC.Dytran model of an all-composite Lear Fan aircraft fuselage was developed to simulate an impact test conducted at the NASA Langley Research Center Impact Dynamics Research Facility (IDRF). The test was the second of two Lear Fan impact tests. The purpose of the second test was to evaluate the performance of retrofitted composite energy-absorbing floor beams. A computerized photogrammetric survey was performed to provide airframe geometric coordinates, and over 5000 points were processed and imported into MSC.Patran via an IGES file. MSC.Patran was then used to develop the curves and surfaces and to mesh the finite element model. A model of the energy-absorbing floor beams was developed separately and then integrated into the Lear Fan model. Structural responses of components such as the wings were compared with experimental data or previously published analytical data wherever possible. Comparisons with experimental results were used to guide structural model modifications to improve the simulation performance. This process was based largely on qualitative (video and still camera images and post-test inspections) rather than quantitative results due to the relatively few accelerometers attached to the structure.

A modified correlation between KJIC and Charpy V-notch impact energy of Chinese SA508-III steel at the upper shelf

NASA Astrophysics Data System (ADS)

Li, Xiangqing; Song, Yuxuan; Ding, Zhenyu; Bao, Shiyi; Gao, Zengliang

2018-07-01

The fracture toughness plays a significant role in the structural integrity assessment of reactor pressure vessels (RPVs) in service temperature. The Charpy V-notch (CVN) impact test is used to estimate fracture toughness (KIC or KJIC) indirectly since universal fracture toughness tests are costly, sophisticated and frequently invalid. In this study, a modified correlation which based on the typical model of KJIC-CVN at the upper shelf was established for Chinese SA508-III steel. Thereinto, the effect of test temperature (T) was directly considered in the correlation. To assess the accuracy of fracture toughness when calculating from the value of Charpy-V notch impact energy by using the modified correlation, both the Charpy-V notch impact tests and fracture toughness tests for Chinese SA508-III steel were conducted at different temperatures (100 °C, 150 °C, 200 °C, 250 °C and 320 °C). The results showed that the modified correlation exhibited the high precision for estimating fracture toughness of Chinese SA508-III steel and the relative error for tested and estimated results is within 8%, which is lower than that of other correlations.

Prosecution of non-disclosure of HIV status: Potential impact on HIV testing and transmission among HIV-negative men who have sex with men.

PubMed

Kesler, Maya A; Kaul, Rupert; Loutfy, Mona; Myers, Ted; Brunetta, Jason; Remis, Robert S; Gesink, Dionne

2018-01-01

Non-disclosure criminal prosecutions among gay, bisexual and other men who have sex with men (MSM) are increasing, even though transmission risk is low when effective antiretroviral treatment (ART) is used. Reduced HIV testing may reduce the impact of HIV "test and treat" strategies. We aimed to quantify the potential impact of non-disclosure prosecutions on HIV testing and transmission among MSM. MSM attending an HIV and primary care clinic in Toronto completed an audio computer-assisted self-interview questionnaire. HIV-negative participants were asked concern over non-disclosure prosecution altered their likelihood of HIV testing. Responses were characterized using cross-tabulations and bivariate logistic regressions. Flow charts modelled how changes in HIV testing behaviour impacted HIV transmission rates controlling for ART use, condom use and HIV status disclosure. 150 HIV-negative MSM were recruited September 2010 to June 2012. 7% (9/124) were less or much less likely to be tested for HIV due to concern over future prosecution. Bivariate regression showed no obvious socio/sexual demographic characteristics associated with decreased willingness of HIV testing to due concern about prosecution. Subsequent models estimated that this 7% reduction in testing could cause an 18.5% increase in community HIV transmission, 73% of which was driven by the failure of HIV-positive but undiagnosed MSM to access care and reduce HIV transmission risk by using ART. Fear of prosecution over HIV non-disclosure was reported to reduce HIV testing willingness by a minority of HIV-negative MSM in Toronto; however, this reduction has the potential to significantly increase HIV transmission at the community level which has important public health implications.

The psychological complexity of predictive testing for late onset neurogenetic diseases and hereditary cancers: implications for multidisciplinary counselling and for genetic education.

PubMed

Evers-Kiebooms, G; Welkenhuysen, M; Claes, E; Decruyenaere, M; Denayer, L

2000-09-01

Increasing knowledge about the human genome has resulted in the availability of a steadily increasing number of predictive DNA-tests for two major categories of diseases: neurogenetic diseases and hereditary cancers. The psychological complexity of predictive testing for these late onset diseases requires careful consideration. It is the main aim of the present paper to describe this psychological complexity, which necessitates an adequate and systematic multidisciplinary approach, including psychological counselling, as well as ongoing education of professionals and of the general public. Predictive testing for neurogenetic diseases--in an adequate counselling context--so far elicits optimism regarding the short- and mid-term impact of the predictive test result. The psychosocial impact has been most widely studied for Huntington's disease. Longitudinal studies are of the utmost importance in evaluating the long-term impact of predictive testing for neurogenetic diseases on the tested person and his/her family. Given the more recent experience with predictive DNA-testing for hereditary cancers, fewer published scientific data are available. Longitudinal research on the mid- and long-term psychological impact of the predictive test result is essential. Decision making regarding health surveillance or preventive surgery after being detected as a carrier of one of the relevant mutations should receive special attention. Tailoring the professional approach--inside and outside genetic centres--to the families' needs is a continuous challenge. Even if a continuous effort is made, several important questions remain unanswered, last but not least the question regarding the best strategy to guarantee that the availability of predictive genetic testing results in a reduction of suffering caused by genetic disease and in an improvement of the quality of life of families confronted with genetic disease.

Prosecution of non-disclosure of HIV status: Potential impact on HIV testing and transmission among HIV-negative men who have sex with men

PubMed Central

Kaul, Rupert; Loutfy, Mona; Myers, Ted; Brunetta, Jason; Gesink, Dionne

2018-01-01

Background Non-disclosure criminal prosecutions among gay, bisexual and other men who have sex with men (MSM) are increasing, even though transmission risk is low when effective antiretroviral treatment (ART) is used. Reduced HIV testing may reduce the impact of HIV “test and treat” strategies. We aimed to quantify the potential impact of non-disclosure prosecutions on HIV testing and transmission among MSM. Methods MSM attending an HIV and primary care clinic in Toronto completed an audio computer-assisted self-interview questionnaire. HIV-negative participants were asked concern over non-disclosure prosecution altered their likelihood of HIV testing. Responses were characterized using cross-tabulations and bivariate logistic regressions. Flow charts modelled how changes in HIV testing behaviour impacted HIV transmission rates controlling for ART use, condom use and HIV status disclosure. Results 150 HIV-negative MSM were recruited September 2010 to June 2012. 7% (9/124) were less or much less likely to be tested for HIV due to concern over future prosecution. Bivariate regression showed no obvious socio/sexual demographic characteristics associated with decreased willingness of HIV testing to due concern about prosecution. Subsequent models estimated that this 7% reduction in testing could cause an 18.5% increase in community HIV transmission, 73% of which was driven by the failure of HIV-positive but undiagnosed MSM to access care and reduce HIV transmission risk by using ART. Conclusions Fear of prosecution over HIV non-disclosure was reported to reduce HIV testing willingness by a minority of HIV-negative MSM in Toronto; however, this reduction has the potential to significantly increase HIV transmission at the community level which has important public health implications. PMID:29489890

Qualification test report bump protection hat (subassembly of T020/M509 head protective assembly)

NASA Technical Reports Server (NTRS)

Willis, D. B.

1972-01-01

The bump protection hat (BPH) was subjected to impact testing in which it underwent three impacts at 35 foot-pounds of energy. The impacts generated stress cracks, but no penetration. All impacts resulted in deflections of less than one-half inch. It was shown that the BPH is qualified for Skylab and the rescue vehicle.

Genomic tests for ovarian cancer detection and management.

PubMed

Myers, Evan R; Havrilesky, Laura J; Kulasingam, Shalini L; Sanders, Gillian D; Cline, Kathryn E; Gray, Rebecca N; Berchuck, Andrew; McCrory, Douglas C

2006-10-01

To assess the evidence that the use of genomic tests for ovarian cancer screening, diagnosis, and treatment leads to improved outcomes. PubMed and reference lists of recent reviews. We evaluated tests for: (a) single gene products; (b) genetic variations affecting risk of ovarian cancer; (c) gene expression; and (d) proteomics. For tests covered in recent evidence reports (cancer antigen 125 [CA-125] and breast cancer genes 1 and 2 [BRCA1/2]), we added studies published subsequent to the reports. We sought evidence on: (a) the analytic performance of tests in clinical laboratories; (b) the sensitivity and specificity of tests in different patient populations; (c) the clinical impact of testing in asymptomatic women, women with suspected ovarian cancer, and women with diagnosed ovarian cancer; (d) the harms of genomic testing; and (e) the impact of direct-to-consumer and direct-to-physician advertising on appropriate use of tests. We also constructed a computer simulation model to test the impact of different assumptions about ovarian cancer natural history on the relative effectiveness of different strategies. There are reasonable data on the clinical laboratory performance of most radioimmunoassays, but the majority of the data on other genomic tests comes from research laboratories. Genomic test sensitivity/specificity estimates are limited by small sample sizes, spectrum bias, and unrealistically large prevalences of ovarian cancer; in particular, estimates of positive predictive values derived from most of the studies are substantially higher than would be expected in most screening or diagnostic settings. We found no evidence relevant to the question of the impact of genomic tests on health outcomes in asymptomatic women. Although there is a relatively large literature on the association of test results and various clinical outcomes, the clinical utility of changing management based on these results has not been evaluated. We found no evidence that genomic tests for ovarian cancer have unique harms beyond those common to other tests for genetic susceptibility or other tests used in screening, diagnosis, and management of ovarian cancer. Studies of a direct-to-consumer campaign for BRCA1/2 testing suggest increased utilization, but the effect on "appropriateness" was unclear. Model simulations suggest that annual screening, even with a highly sensitive test, will not reduce ovarian cancer mortality by more than 50 percent; frequent screening has a very low positive predictive value, even with a highly specific test. Although research remains promising, adaptation of genomic tests into clinical practice must await appropriately designed and powered studies in relevant clinical settings.

Impact Behavior of Composite Fan Blade Leading Edge Subcomponent with Thermoplastic Polyurethane Interleave

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Roberts, Gary D.; Kohlman, Lee W.; Heimann, Paula J.; Pereira, J. Michael; Ruggeri, Charles R.; Martin, Richard E.; McCorkle, Linda S.

2015-01-01

Impact damage tolerance and damage resistance is a critical metric for application of polymer matrix composites where failure caused by impact damage could compromise structural performance and safety. As a result, several materials and/or design approaches to improve impact damage tolerance have been investigated over the past several decades. Many composite toughening methodologies impart a trade-off between increased fracture toughness and compromised in-plane strength and modulus. In large part, mechanical tests to evaluate composite damage tolerance include static methods such as Mode I, Mode II, and mixed mode failures. However, ballistic impact damage resistance does not always correlate with static properties. The intent of this paper is to evaluate the influence of a thermoplastic polyurethane veil interleave on the static and dynamic performance of composite test articles. Static coupon tests included tension, compression, double cantilever beam, and end notch flexure. Measurement of the resistance to ballistic impact damage were made to evaluate the composites response to high speed impact. The interlayer material showed a decrease of in-plane performance with only a moderate improvement to Mode I and Mode II fracture toughness. However, significant benefit to impact damage tolerance was observed through ballistic tests.

Production development of organic nonflammable spacecraft potting, encapsulating and conformal coating compounds. Volume 3: Appendices

NASA Technical Reports Server (NTRS)

Lieberman, S. L.

1974-01-01

Appendices are presented which include: statement of work; material vendor contacts; formulation/processing data sheet; upward propagation test; flammability test conditions/results sheet; odor test; vacuum stability requirements; flammability test facility; determination of offgassing products and carbon monoxide test; and pneumatic and mechanical impact test guidelines.

Testing of small and large sign support systems FOIL test number : 92F011

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92FOll. The vehicle used for these t...

Testing of small and large sign support systems FOIL test number : 92F036

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 60 mi/h (96.6 km/h), test 92F036. The vehicle used for this ...

Testing of small and large sign support systems FOIL test number : 92F016

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor : Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign : support system at 20 mi/h (8.9 m/s), test 92F016. The vehicle used for the...

Testing of small and large sign support systems FOIL test number : 92F035

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (32.2 km/h), test 92F035. The vehicle used for this ...

Testing of small and large sign support systems FOIL test number : 92F038

DOT National Transportation Integrated Search

1994-01-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 60 mi/h (96.6 km/h), test 92F038. The vehicle used for this ...

Testing of small and large sign support systems FOIL test number : 92F037

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (32.2 km/h), test 92F037. The vehicle used for this ...

Testing of small and large sign support systems FOIL test number : 92F022

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact laboratory (FOIL) in Mclean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s) , test 92F022. The vehicle used for this t...

Testing of small and large sign support systems FOIL test numbers : 92F040

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 60 mi/h (96.6 km/h), test 92F040. The vehicle used for this ...

Testing of small and large sign support systems FOIL test number : 92F039

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (32.2 km/h) , test 92F039. The vehicle used for this...

The cost of genetic testing for ocular disease: who pays?

PubMed

Capasso, Jenina E

2014-09-01

To facilitate ophthalmologists' understanding on the cost of genetic testing in ocular disease, the complexities of insurance coverage and its impact on the availability of testing. Many insurance carriers address coverage for genetic testing in written clinical policies. They provide criteria for medically necessary testing. These policies mostly cover testing for individuals who are symptomatic and in whom testing will have a direct impact on medical treatment. In cases in which no treatments are currently available, other than research trials, patients may have difficulty in getting insurance coverage for genetic testing. Genetic testing for inherited eye diseases can be costly but has many benefits to patient care, including confirmation of a diagnosis, insight into prognostic information, and identification of associated health risks, inheritance patterns, and possible current and future treatments. As gene therapy advances progress, the availability for treatment in ocular diseases, coverage for genetic testing by third-party payers could increase on the basis of current clinical policies.

A Residual Mass Ballistic Testing Method to Compare Armor Materials or Components (Residual Mass Ballistic Testing Method)

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

Benjamin Langhorst; Thomas M Lillo; Henry S Chu

2014-05-01

A statistics based ballistic test method is presented for use when comparing multiple groups of test articles of unknown relative ballistic perforation resistance. The method is intended to be more efficient than many traditional methods for research and development testing. To establish the validity of the method, it is employed in this study to compare test groups of known relative ballistic performance. Multiple groups of test articles were perforated using consistent projectiles and impact conditions. Test groups were made of rolled homogeneous armor (RHA) plates and differed in thickness. After perforation, each residual projectile was captured behind the target andmore » its mass was measured. The residual masses measured for each test group were analyzed to provide ballistic performance rankings with associated confidence levels. When compared to traditional V50 methods, the residual mass (RM) method was found to require fewer test events and be more tolerant of variations in impact conditions.« less

A Summary of DOD-Sponsored Research Performed at NASA Langley's Impact Dynamics Research Facility

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.; Lyle, Karen H.

2004-01-01

The Impact Dynamics Research Facility (IDRF) is a 240-ft.-high gantry structure located at NASA Langley Research Center in Hampton, Virginia. The IDRF was originally built in the early 1960's for use as a Lunar Landing Research Facility. As such, the facility was configured to simulate the reduced gravitational environment of the Moon, allowing the Apollo astronauts to practice lunar landings under realistic conditions. In 1985, the IDRF was designated a National Historic Landmark based on its significant contributions to the Apollo Moon Landing Program. In the early 1970's the facility was converted into its current configuration as a full-scale crash test facility for light aircraft and rotorcraft. Since that time, the IDRF has been used to perform a wide variety of impact tests on full-scale aircraft, airframe components, and space vehicles in support of the General Aviation (GA) aircraft industry, the U.S. Department of Defense (DOD), the rotorcraft industry, and the NASA Space program. The objectives of this paper are twofold: to describe the IDRF facility and its unique capabilities for conducting structural impact testing, and to summarize the impact tests performed at the IDRF in support of the DOD. These tests cover a time period of roughly 2 1/2 decades, beginning in 1975 with the full-scale crash test of a CH-47 Chinook helicopter, and ending in 1999 with the external fuel system qualification test of a UH-60 Black Hawk helicopter. NASA officially closed the IDRF in September 2003; consequently, it is important to document the past contributions made in improved human survivability and impact tolerance through DOD-sponsored research performed at the IDRF.

Budget impact analysis of chronic kidney disease mass screening test in Japan.

PubMed

Kondo, Masahide; Yamagata, Kunihiro; Hoshi, Shu-Ling; Saito, Chie; Asahi, Koichi; Moriyama, Toshiki; Tsuruya, Kazuhiko; Konta, Tsuneo; Fujimoto, Shouichi; Narita, Ichiei; Kimura, Kenjiro; Iseki, Kunitoshi; Watanabe, Tsuyoshi

2014-12-01

Our recently published cost-effectiveness study on chronic kidney disease mass screening test in Japan evaluated the use of dipstick test, serum creatinine (Cr) assay or both in specific health checkup (SHC). Mandating the use of serum Cr assay additionally, or the continuation of current policy mandating dipstick test only was found cost-effective. This study aims to examine the affordability of previously suggested reforms. Budget impact analysis was conducted assuming the economic model would be good for 15 years and applying a population projection. Costs expended by social insurers without discounting were counted as budgets. Annual budget impacts of mass screening compared with do-nothing scenario were calculated as ¥79-¥-1,067 million for dipstick test only, ¥2,505-¥9,235 million for serum Cr assay only and ¥2,517-¥9,251 million for the use of both during a 15-year period. Annual budget impacts associated with the reforms were calculated as ¥975-¥4,129 million for mandating serum Cr assay in addition to the currently used mandatory dipstick test, and ¥963-¥4,113 million for mandating serum Cr assay only and abandoning dipstick test. Estimated values associated with the reform from ¥963-¥4,129 million per year over 15 years are considerable amounts of money under limited resources. The most impressive finding of this study is the decreasing additional expenditures in dipstick test only scenario. This suggests that current policy which mandates dipstick test only would contain medical care expenditure.

Impact Landing Dynamics Facility Crash Test

NASA Image and Video Library

1975-08-03

Photographed on: 08/03/75. -- By 1972 the Lunar Landing Research Facility was no longer in use for its original purpose. The 400-foot high structure was swiftly modified to allow engineers to study the dynamics of aircraft crashes. "The Impact Dynamics Research Facility is used to conduct crash testing of full-scale aircraft under controlled conditions. The aircraft are swung by cables from an A-frame structure that is approximately 400 ft. long and 230 foot high. The impact runway can be modified to simulate other grand crash environments, such as packed dirt, to meet a specific test requirement." "In 1972, NASA and the FAA embarked on a cooperative effort to develop technology for improved crashworthiness and passenger survivability in general aviation aircraft with little or no increase in weight and acceptable cost. Since then, NASA has "crashed" dozens of GA aircraft by using the lunar excursion module (LEM) facility originally built for the Apollo program." This photograph shows Crash Test No. 7. Crash Test: Test #7

Arcjet Testing of Micro-Meteoroid Impacted Thermal Protection Materials

NASA Technical Reports Server (NTRS)

Agrawal, Parul; Munk, Michelle M.; Glaab, Louis J.

2013-01-01

There are several harsh space environments that could affect thermal protection systems and in turn pose risks to the atmospheric entry vehicles. These environments include micrometeoroid impact, extreme cold temperatures, and ionizing radiation during deep space cruise, all followed by atmospheric entry heating. To mitigate these risks, different thermal protection material samples were subjected to multiple tests, including hyper velocity impact, cold soak, irradiation, and arcjet testing, at various NASA facilities that simulated these environments. The materials included a variety of honeycomb packed ablative materials as well as carbon-based non-ablative thermal protection systems. The present paper describes the results of the multiple test campaign with a focus on arcjet testing of thermal protection materials. The tests showed promising results for ablative materials. However, the carbon-based non-ablative system presented some concerns regarding the potential risks to an entry vehicle. This study provides valuable information regarding the capability of various thermal protection materials to withstand harsh space environments, which is critical to sample return and planetary entry missions.

Response of an Impact Test Apparatus for Fall Protective Headgear Testing Using a Hybrid-III Head/Neck Assembly

PubMed Central

Caccese, V.; Ferguson, J.; Lloyd, J.; Edgecomb, M.; Seidi, M.; Hajiaghamemar, M.

2017-01-01

A test method based upon a Hybrid-III head and neck assembly that includes measurement of both linear and angular acceleration is investigated for potential use in impact testing of protective headgear. The test apparatus is based upon a twin wire drop test system modified with the head/neck assembly and associated flyarm components. This study represents a preliminary assessment of the test apparatus for use in the development of protective headgear designed to prevent injury due to falls. By including angular acceleration in the test protocol it becomes possible to assess and intentionally reduce this component of acceleration. Comparisons of standard and reduced durometer necks, various anvils, front, rear, and side drop orientations, and response data on performance of the apparatus are provided. Injury measures summarized for an unprotected drop include maximum linear and angular acceleration, head injury criteria (HIC), rotational injury criteria (RIC), and power rotational head injury criteria (PRHIC). Coefficient of variation for multiple drops ranged from 0.4 to 6.7% for linear acceleration. Angular acceleration recorded in a side drop orientation resulted in highest coefficient of variation of 16.3%. The drop test apparatus results in a reasonably repeatable test method that has potential to be used in studies of headgear designed to reduce head impact injury. PMID:28216804

Qualifying Spirit and Opportunity to Martian Landing Loads with Centrifuge Testing

NASA Technical Reports Server (NTRS)

Coleman, Michelle R.; Davis, Greg

2004-01-01

This viewgraph presentation reviews the drop test used to test the Mars lander. The objective of the test was to demonstrate the structural and functional integrity of the development test Model (DTM). Rover Basepetal when subjected to the landing event. The test module was instrumented with accelerometers to measure the kinematic response of the test article during impact.

The Internationalization of Testing and New Models of Test Delivery on the Internet

ERIC Educational Resources Information Center

Bartram, Dave

2006-01-01

The Internet has opened up a whole new set of opportunities for advancing the science of psychometrics and the technology of testing. It has also created some new challenges for those of us involved in test design and testing. In particular, we are seeing impacts from internationalization of testing and new models for test delivery. These are…

Failure Behavior Characterization of Mo-Modified Ti Surface by Impact Test and Finite Element Analysis

NASA Astrophysics Data System (ADS)

Ma, Yong; Qin, Jianfeng; Zhang, Xiangyu; Lin, Naiming; Huang, Xiaobo; Tang, Bin

2015-07-01

Using the impact test and finite element simulation, the failure behavior of the Mo-modified layer on pure Ti was investigated. In the impact test, four loads of 100, 300, 500, and 700 N and 104 impacts were adopted. The three-dimensional residual impact dents were examined using an optical microscope (Olympus-DSX500i), indicating that the impact resistance of the Ti surface was improved. Two failure modes cohesive and wearing were elucidated by electron backscatter diffraction and energy-dispersive spectrometer performed in a field-emission scanning electron microscope. Through finite element forward analysis performed at a typical impact load of 300 N, stress-strain distributions in the Mo-modified Ti were quantitatively determined. In addition, the failure behavior of the Mo-modified layer was determined and an ideal failure model was proposed for high-load impact, based on the experimental and finite element forward analysis results.

Laboratory testing in primary care: A systematic review of health IT impacts.

PubMed

Maillet, Éric; Paré, Guy; Currie, Leanne M; Raymond, Louis; Ortiz de Guinea, Ana; Trudel, Marie-Claude; Marsan, Josianne

2018-08-01

Laboratory testing in primary care is a fundamental process that supports patient management and care. Any breakdown in the process may alter clinical information gathering and decision-making activities and can lead to medical errors and potential adverse outcomes for patients. Various information technologies are being used in primary care with the goal to support the process, maximize patient benefits and reduce medical errors. However, the overall impact of health information technologies on laboratory testing processes has not been evaluated. To synthesize the positive and negative impacts resulting from the use of health information technology in each phase of the laboratory 'total testing process' in primary care. We conducted a systematic review. Databases including Medline, PubMed, CINAHL, Web of Science and Google Scholar were searched. Studies eligible for inclusion reported empirical data on: 1) the use of a specific IT system, 2) the impacts of the systems to support the laboratory testing process, and were conducted in 3) primary care settings (including ambulatory care and primary care offices). Our final sample consisted of 22 empirical studies which were mapped to a framework that outlines the phases of the laboratory total testing process, focusing on phases where medical errors may occur. Health information technology systems support several phases of the laboratory testing process, from ordering the test to following-up with patients. This is a growing field of research with most studies focusing on the use of information technology during the final phases of the laboratory total testing process. The findings were largely positive. Positive impacts included easier access to test results by primary care providers, reduced turnaround times, and increased prescribed tests based on best practice guidelines. Negative impacts were reported in several studies: paper-based processes employed in parallel to the electronic process increased the potential for medical errors due to clinicians' cognitive overload; systems deemed not reliable or user-friendly hampered clinicians' performance; and organizational issues arose when results tracking relied on the prescribers' memory. The potential of health information technology lies not only in the exchange of health information, but also in knowledge sharing among clinicians. This review has underscored the important role played by cognitive factors, which are critical in the clinician's decision-making, the selection of the most appropriate tests, correct interpretation of the results and efficient interventions. By providing the right information, at the right time to the right clinician, many IT solutions adequately support the laboratory testing process and help primary care clinicians make better decisions. However, several technological and organizational barriers require more attention to fully support the highly fragmented and error-prone process of laboratory testing. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluating the test-retest reliability of symptom indices associated with the ImPACT post-concussion symptom scale (PCSS).

PubMed

Merritt, Victoria C; Bradson, Megan L; Meyer, Jessica E; Arnett, Peter A

2018-05-01

The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a commonly used tool in sports concussion assessment. While test-retest reliabilities have been established for the ImPACT cognitive composites, few studies have evaluated the psychometric properties of the ImPACT's Post-Concussion Symptom Scale (PCSS). The purpose of this study was to establish the test-retest reliability of symptom indices associated with the PCSS. Participants included 38 undergraduate students (50.0% male) who underwent neuropsychological testing as part of their participation in their psychology department's research subject pool. The majority of the participants were Caucasian (94.7%) and had no history of concussion (73.7%). All participants completed the ImPACT at two time points, approximately 6 weeks apart. The PCSS was the main outcome measure, and eight symptom indices were calculated (a total symptom score, three symptom summary indices, and four symptom clusters). Pearson correlations (r) and intraclass correlation coefficients (ICCs) were computed as measures of test-retest reliability. Overall, reliabilities ranged from low to high (r = .44 to .80; ICC = .44 to .77). The cognitive symptom cluster exhibited the highest test-retest reliability (r = .80, ICC = .77), followed by the positive symptom total (PST) index, an indicator of the total number of symptoms endorsed (r = .71, ICC = .69). In contrast, the commonly used total symptom score showed lower test-retest reliability (r = .67, ICC = .62). Paired-samples t tests revealed no significant differences between test and retest for any of the symptom variables (all p > .01). Finally, reliable change indices (RCI) were computed to determine whether differences observed between test and retest represented clinically significant change. RCI values were provided for each symptom index at the 80%, 90%, and 95% confidence intervals. These results suggest that evaluating additional symptom indices beyond the total symptom score from the PCSS is beneficial. Findings from this study can be applied to athlete samples to assess reliable change in symptoms following concussion.

Long-term Stability and Reliability of Baseline Cognitive Assessments in High School Athletes Using ImPACT at 1-, 2-, and 3-year Test-Retest Intervals.

PubMed

Brett, Benjamin L; Smyk, Nathan; Solomon, Gary; Baughman, Brandon C; Schatz, Philip

2016-08-18

The ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) neurocognitive testing battery is a widely used tool used for the assessment and management of sports-related concussion. Research on the stability of ImPACT in high school athletes at a 1- and 2-year intervals have been inconsistent, requiring further investigation. We documented 1-, 2-, and 3-year test-retest reliability of repeated ImPACT baseline assessments in a sample of high school athletes, using multiple statistical methods for examining stability. A total of 1,510 high school athletes completed baseline cognitive testing using online ImPACT test battery at three time periods of approximately 1- (N = 250), 2- (N = 1146), and 3-year (N = 114) intervals. No participant sustained a concussion between assessments. Intraclass correlation coefficients (ICCs) ranged in composite scores from 0.36 to 0.90 and showed little change as intervals between assessments increased. Reliable change indices and regression-based measures (RBMs) examining the test-retest stability demonstrated a lack of significant change in composite scores across the various time intervals, with very few cases (0%-6%) falling outside of 95% confidence intervals. The results suggest ImPACT composites scores remain considerably stability across 1-, 2-, and 3-year test-retest intervals in high school athletes, when considering both ICCs and RBM. Annually ascertaining baseline scores continues to be optimal for ensuring accurate and individualized management of injury for concussed athletes. For instances in which more recent baselines are not available (1-2 years), clinicians should seek to utilize more conservative range estimates in determining the presence of clinically meaningful change in cognitive performance. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Biofidelity assessment of the 6-year-old ATDs in lateral impact.

PubMed

Yaek, J L; Li, Y; Lemanski, P J; Begeman, P C; Rouhana, S W; Cavanaugh, J M

2016-07-03

The objective of this study was to assess and compare the current lateral impact biofidelity of the shoulder, thorax, abdomen, and pelvis of the Q6, Q6s, and Hybrid III (HIII) 6-year-old anthropomorphic test devices (ATDs) through lateral impact testing. A series of lateral impact pendulum tests, vertical drop tests, and Wayne State University (WSU) sled tests was performed, based on the procedures detailed in ISO/TR 9790 (1999) and scaling to the 6-year-old using Irwin et al. ( 2002 ). The HIII used in this study was tested with the Ford-designed abdomen described in Rouhana ( 2006 ) and Elhagediab et al. ( 2006 ). The data collected from the 3 different ATDs were filtered using SAE J211 (SAE International 2003 ), aligned using the methodology described by Donnelly and Moorhouse ( 2012 ), and compared for each body region tested (shoulder, thorax, abdomen, and pelvis). The biofidelity performance in lateral impact for the 3 ATDs was assessed against the scaled biofidelity targets published in Irwin et al. ( 2002 ), the abdominal biofidelity target suggested in van Ratingen et al. ( 1997 ), and the biofidelity targets published in Rhule et al. ( 2013 ). Regional and overall biofidelity rankings for each of the 3 ATDs were performed using both the ISO 9790 biofidelity rating system (ISO/TR 9790 1999) and the NHTSA's external biofidelity ranking system (BRS; Rhule et al. 2013 ). All 3 6-year-old ATD's pelvises were rated as least biofidelic of the 4 body regions tested, based on both the ISO and BRS biofidelity rating systems, followed by the shoulder and abdomen, respectively. The thorax of all 3 ATDs was rated as the most biofidelic body region using the aforementioned biofidelity rating systems. The HIII 6-year-old ATD was rated last in overall biofidelity of the 3 tested ATDs, based on both rating systems. The Q6s ATD was rated as having the best overall biofidelity using both rating systems. All 3 ATDs are more biofidelic in the thorax and abdomen than the shoulder and pelvis, with the pelvis being the least biofidelic of all 4 tested body regions. None of the 3 tested 6-year-old ATDs had an overall ranking of 2.0 or less, based on the BRS ranking. Therefore, it is expected that none of the 3 ATDs would mechanically respond like a postmortem human subject (PMHS) in a lateral impact crash test based on this ranking system. With respect to the ISO biofidelity rating, the HIII dummy would be considered unsuitable and the Q-series dummies would be considered marginal for assessing side impact occupant protection.

Impact of Enteroviral Polymerase Chain Reaction Testing on Length of Stay for Infants 60 Days Old or Younger.

PubMed

Aronson, Paul L; Lyons, Todd W; Cruz, Andrea T; Freedman, Stephen B; Okada, Pamela J; Fleming, Alesia H; Arms, Joseph L; Thompson, Amy D; Schmidt, Suzanne M; Louie, Jeffrey; Alfonzo, Michael J; Monuteaux, Michael C; Nigrovic, Lise E

2017-10-01

To determine the impact of a cerebrospinal fluid enterovirus polymerase chain reaction (PCR) test performance on hospital length of stay (LOS) in a large multicenter cohort of infants undergoing evaluation for central nervous system infection. We performed a planned secondary analysis of a retrospective cohort of hospitalized infants ≤60 days of age who had a cerebrospinal fluid culture obtained at 1 of 18 participating centers (2005-2013). After adjustment for patient age and study year as well as clustering by hospital center, we compared LOS for infants who had an enterovirus PCR test performed vs not performed and among those tested, for infants with a positive vs negative test result. Of 19 953 hospitalized infants, 4444 (22.3%) had an enterovirus PCR test performed and 945 (21.3% of tested infants) had positive test results. Hospital LOS was similar for infants who had an enterovirus PCR test performed compared with infants who did not (incident rate ratio 0.98 hours; 95% CI 0.89-1.06). However, infants PCR positive for enterovirus had a 38% shorter LOS than infants PCR negative for enterovirus (incident rate ratio 0.62 hours; 95% CI 0.57-0.68). No infant with a positive enterovirus PCR test had bacterial meningitis (0%; 95% CI 0-0.4). Although enterovirus PCR testing was not associated with a reduction in LOS, infants with a positive enterovirus PCR test had a one-third shorter LOS compared with infants with a negative enterovirus PCR test. Focused enterovirus PCR test use could increase the impact on LOS for infants undergoing cerebrospinal fluid evaluation. Copyright © 2017 Elsevier Inc. All rights reserved.

TRACT 2 Frame Drop Test AT NASA Langley Research Center's Landin

NASA Image and Video Library

2014-05-09

(Tract)2 Transport Rotorcraft Airframe Crash Testbed; Full Frame Drop Test: rotary wing crash worthiness, impact research at NASA Langley Research Center's Landing and Impact Research (LandIR) Facility Building 1297

Results of a conventional fuel tank blunt impact test

DOT National Transportation Integrated Search

2015-03-23

The Federal Railroad Administrations Office of Research : and Development is conducting research into passenger : locomotive fuel tank crashworthiness. A series of impact tests is : being conducted to measure fuel tank deformation under two : type...

A qualitative exploration of student perceptions of the impact of progress tests on learning and emotional wellbeing.

PubMed

Yielder, Jill; Wearn, Andy; Chen, Yan; Henning, Marcus A; Weller, Jennifer; Lillis, Steven; Mogol, Vernon; Bagg, Warwick

2017-08-29

Progress testing was introduced to the MBChB programme at the University of Auckland in 2013. As there has been a focus in published literature on aspects relating to the format or function of progress tests, the purpose of this study was to explore a qualitative student perspective on the introduction of progress testing and its impact on approaches to learning and perceived stress. This article presents the qualitative aspects of a longitudinal evaluation study. The qualitative data were derived from eight focus groups of Year 2-5 medical students in the University of Auckland medical programme. Two themes, 'Impact on Learning' and 'Emotional Wellbeing' and their subthemes offered insight into student perceptions and behaviour. Students described a variety of learning responses to progress testing that clustered around the employment of a range of learning strategies based on their experience of sitting progress tests and their individualised feedback. A range of emotional responses were also expressed, with some finding progress tests stressful, while others enjoyed not needing to intensively cram before the tests. Progress tests appear to influence the approach of students to their learning. They employ a mix of learning strategies, shaped by their performance, individualised feedback and the learning environment. While students expressed some stress and anxiety with respect to sitting progress tests, this form of testing was viewed by these students as no worse, and sometimes better than traditional assessments.

Evaluation of nitrous oxide as a substitute for sulfur hexafluoride to reduce global warming impacts of ANSI/HPS N13.1 gaseous uniformity testing

NASA Astrophysics Data System (ADS)

Yu, Xiao-Ying; Barnett, J. Matthew; Amidan, Brett G.; Recknagle, Kurtis P.; Flaherty, Julia E.; Antonio, Ernest J.; Glissmeyer, John A.

2018-03-01

The ANSI/HPS N13.1-2011 standard requires gaseous tracer uniformity testing for sampling associated with stacks used in radioactive air emissions. Sulfur hexafluoride (SF6), a greenhouse gas with a high global warming potential, has long been the gas tracer used in such testing. To reduce the impact of gas tracer tests on the environment, nitrous oxide (N2O) was evaluated as a potential replacement to SF6. The physical evaluation included the development of a test plan to record percent coefficient of variance and the percent maximum deviation between the two gases while considering variables such as fan configuration, injection position, and flow rate. Statistical power was calculated to determine how many sample sets were needed, and computational fluid dynamic modeling was utilized to estimate overall mixing in stacks. Results show there are no significant differences between the behaviors of the two gases, and SF6 modeling corroborated N2O test results. Although, in principle, all tracer gases should behave in an identical manner for measuring mixing within a stack, the series of physical tests guided by statistics was performed to demonstrate the equivalence of N2O testing to SF6 testing in the context of stack qualification tests. The results demonstrate that N2O is a viable choice leading to a four times reduction in global warming impacts for future similar compliance driven testing.

Crash Tests of Work Zone Traffic Control Devices

DOT National Transportation Integrated Search

1990-02-01

Full-scale vehicle crash tests evaluated performance of typical work zone traffic control devices. Modified test procedures and evaluation criteria from NCHRP Report 230 were used in 108 tests, providing significant insight into impact performance. P...

Testing of the masonry arches of the Brooklyn Bridge approaches

NASA Astrophysics Data System (ADS)

Limaye, Hemant S.

1996-11-01

Diagnostic procedures play an important role in performing a condition survey of a structure. Specialized tests are used during a field survey to supplement visual observations. The tests provide valuable information regarding the internal condition of the structure and quality of the construction materials. The tests also help in determining the extent of damage, if any. Recently, a team of consulting engineers performed a study to determine the remaining capacity of the Brooklyn Bridge approaches for the Department of Transportation, City of New York. Using advanced diagnostic procedures such as impact-echo and flatjack testing, additional information was gathered to assist in the study. Impact-echo testing was helpful in identifying the condition of the brick soffits which were covered with pneumatically- applied concrete, and flatjack testing was useful in determining in-situ compressive strength and compression modulus of the brick masonry. The paper describes the work and the testing results.

Fabrication and Testing of Durable Redundant and Fluted-Core Joints for Composite Sandwich Structures

NASA Technical Reports Server (NTRS)

Lin, Shih-Yung; Splinter, Scott C.; Tarkenton, Chris; Paddock, David A.; Smeltzer, Stanley S.; Ghose, Sayata; Guzman, Juan C.; Stukus, Donald J.; McCarville, Douglas A.

2013-01-01

The development of durable bonded joint technology for assembling composite structures is an essential component of future space technologies. While NASA is working toward providing an entirely new capability for human space exploration beyond low Earth orbit, the objective of this project is to design, fabricate, analyze, and test a NASA patented durable redundant joint (DRJ) and a NASA/Boeing co-designed fluted-core joint (FCJ). The potential applications include a wide range of sandwich structures for NASA's future launch vehicles. Three types of joints were studied -- splice joint (SJ, as baseline), DRJ, and FCJ. Tests included tension, after-impact tension, and compression. Teflon strips were used at the joint area to increase failure strength by shifting stress concentration to a less sensitive area. Test results were compared to those of pristine coupons fabricated utilizing the same methods. Tensile test results indicated that the DRJ design was stiffer, stronger, and more impact resistant than other designs. The drawbacks of the DRJ design were extra mass and complex fabrication processes. The FCJ was lighter than the DRJ but less impact resistant. With barely visible but detectable impact damages, all three joints showed no sign of tensile strength reduction. No compression test was conducted on any impact-damaged sample due to limited scope and resource. Failure modes and damage propagation were also studied to support progressive damage modeling of the SJ and the DRJ.

Evaluation of Progressive Failure Analysis and Modeling of Impact Damage in Composite Pressure Vessels

NASA Technical Reports Server (NTRS)

Sanchez, Christopher M.

2011-01-01

NASA White Sands Test Facility (WSTF) is leading an evaluation effort in advanced destructive and nondestructive testing of composite pressure vessels and structures. WSTF is using progressive finite element analysis methods for test design and for confirmation of composite pressure vessel performance. Using composite finite element analysis models and failure theories tested in the World-Wide Failure Exercise, WSTF is able to estimate the static strength of composite pressure vessels. Additionally, test and evaluation on composites that have been impact damaged is in progress so that models can be developed to estimate damage tolerance and the degradation in static strength.

Test and analysis results for composite transport fuselage and wing structures

NASA Technical Reports Server (NTRS)

Deaton, Jerry W.; Kullerd, Susan M.; Madan, Ram C.; Chen, Victor L.

1992-01-01

Automated tow placement (ATP) and stitching of dry textile composite preforms followed by resin transfer molding (RTM) are being studied as cost effective manufacturing processes for obtaining damage tolerant fuselage and wing structures for transport aircraft. Data are presented to assess the damage tolerance of ATP and RTM fuselage elements with stitched-on stiffeners from compression tests of impacted three J-stiffened panels and from stiffener pull-off tests. Data are also presented to assess the damage tolerance of RTM wing elements which had stitched skin and stiffeners from impacted single stiffener and three blade stiffened compression tests and stiffener pull-off tests.

Impact Testing of Explosives and Propellants

DTIC Science & Technology

1992-06-01

in order to better understand the test results. The physical behavior of tile drop weight impact test can be modeled on a computer with all of the...SPRING ELEMENTS OF SIMPLIFIED IMPACT MACHINE A-4 NSV’CDDITR-92/280 4 j DISTRIBUTION Copies C~e ATTN ONR 1132P (R MILLER ) 1 ATTN 6-A-145 1 ONT2OT(L V...LIBRARY OF CONGRESS (J W FORBES) 1 WASHINGTON DC 20540 (R11 GUIRGUIS ) 1 (P K GUSTAVSON) I INTERNAL DISTRIBUTION (R N HAY) ! E231 2 (It D JONES) 1 E232 3 (K

Quasi-Uniform High Speed Foam Crush Testing Using a Guided Drop Mass Impact

NASA Technical Reports Server (NTRS)

Jones, Lisa E. (Technical Monitor); Kellas, Sotiris

2004-01-01

A relatively simple method for measuring the dynamic crush response of foam materials at various loading rates is described. The method utilizes a drop mass impact configuration with mass and impact velocity selected such that the crush speed remains approximately uniform during the entire sample crushing event. Instrumentation, data acquisition, and data processing techniques are presented, and limitations of the test method are discussed. The objective of the test method is to produce input data for dynamic finite element modeling involving crash and energy absorption characteristics of foam materials.

Design and Testing of Braided Composite Fan Case Materials and Components

NASA Technical Reports Server (NTRS)

Roberts, Gary D.; Pereira, J. Michael; Braley, Michael S.; Arnold, William a.; Dorer, James D.; Watson, William R/.

2009-01-01

Triaxial braid composite materials are beginning to be used in fan cases for commercial gas turbine engines. The primary benefit for the use of composite materials is reduced weight and the associated reduction in fuel consumption. However, there are also cost benefits in some applications. This paper presents a description of the braided composite materials and discusses aspects of the braiding process that can be utilized for efficient fabrication of composite cases. The paper also presents an approach that was developed for evaluating the braided composite materials and composite fan cases in a ballistic impact laboratory. Impact of composite panels with a soft projectile is used for materials evaluation. Impact of composite fan cases with fan blades or blade-like projectiles is used to evaluate containment capability. A post-impact structural load test is used to evaluate the capability of the impacted fan case to survive dynamic loads during engine spool down. Validation of these new test methods is demonstrated by comparison with results of engine blade-out tests.

Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

PubMed Central

Randjbaran, Elias; Zahari, Rizal; Abdul Jalil, Nawal Aswan; Abang Abdul Majid, Dayang Laila

2014-01-01

Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers. PMID:24955400

A new class of high-G and long-duration shock testing machines

NASA Astrophysics Data System (ADS)

Rastegar, Jahangir

2018-03-01

Currently available methods and systems for testing components for survival and performance under shock loading suffer from several shortcomings for use to simulate high-G acceleration events with relatively long duration. Such events include most munitions firing and target impact, vehicular accidents, drops from relatively high heights, air drops, impact between machine components, and other similar events. In this paper, a new class of shock testing machines are presented that can be used to subject components to be tested to high-G acceleration pulses of prescribed amplitudes and relatively long durations. The machines provide for highly repeatable testing of components. The components are mounted on an open platform for ease of instrumentation and video recording of their dynamic behavior during shock loading tests.

Oxidation of Reinforced Carbon-Carbon Subjected to Hypervelocity Impact

NASA Technical Reports Server (NTRS)

Curry, Donald M.; Pham, Vuong T.; Norman, Ignacio; Chao, Dennis C.

2000-01-01

This paper presents results from arc jet tests conducted at the NASA Johnson Space Center on reinforced carbon-carbon (RCC) samples subjected to hypervelocity impact. The RCC test specimens are representative of RCC components used on the Space Shuttle Orbiter. The arc jet testing established the oxidation characteristics of RCC when hypervelocity projectiles, simulating meteoroid/orbital debris, impact the RCC material. In addition to developing correlations for use in trajectory simulations, we discuss analytical modeling of the increased material oxidation in the impacted area using measured hole growth data. Entry flight simulations are useful in assessing the increased Space Shuttle RCC component degradation as a result of impact damage and the hot gas flow through an enlarging hole into the wing leading-edge cavity.

Simple go/no-go test for subcritical damage in body armor panels

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

Fisher, Jason; Chimenti, D. E.

2011-06-23

The development of a simple test for subcritical damage in body armor panels using pressure-sensitive dye-indicator film has been performed and demonstrated effective. Measurements have shown that static indicator levels are accurately reproduced in dynamic loading events. Impacts from hard blunt impactors instrumented with an accelerometer and embedded force transducer were studied. Reliable correlations between the indicator film and instrumented impact force are shown for a range of impact energies. Force and acceleration waveforms with corresponding indicator film results are presented for impact events onto damaged and undamaged panels. We find that panel damage can occur at impact levels farmore » below the National Institute of Justice acceptance test standard.« less

Prediction of the effect of temperature on impact damage in carbon/epoxy laminates

NASA Astrophysics Data System (ADS)

Gómez del Río, T.; Zaera, R.; Navarro, C.

2003-09-01

The effect of temperature on impact damage in Carbon Fiber Reinforced Plastic (CFRP) tape laminates produced by low velocity impact was studied by numerical simulations made to model drop weight tower impact tests on carbon/epoxy laminate composites. The damage model was implemented into a user subroutine of the finite element code ABAQUS. The model takes into account the thermal stresses resulting form the different thermal expansion coefficients in each ply of the laminate. The tests and simulations show how temperature affects the propagation of each damage mode. Matrix cracking and delamination are greatly affected by low temperature, white matrix crushing and fibre failure appear only in a small region at all the impact energies and test temperatures.

49 CFR 572.134 - Thorax assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... completely assembled dummy (drawing 880105-000) is impacted by a test probe conforming to section 572.137(a...). Within this specified compression corridor, the peak force, measured by the impact probe as defined in... midsagittal plane so that the impact point of the longitudinal centerline of the probe coincides with the...

49 CFR 572.134 - Thorax assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... completely assembled dummy (drawing 880105-000) is impacted by a test probe conforming to section 572.137(a...). Within this specified compression corridor, the peak force, measured by the impact probe as defined in... midsagittal plane so that the impact point of the longitudinal centerline of the probe coincides with the...

49 CFR 572.10 - Limbs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of the forward edge of the seat. (3) Align the test probe specified in § 572.11(a) so that at impact...) Impact the knee with the test probe moving horizontally and parallel to the midsagittal plane at the specified velocity. (5) Guide the probe during impact so that it moves with no significant lateral, vertical...

49 CFR 572.134 - Thorax assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... completely assembled dummy (drawing 880105-000) is impacted by a test probe conforming to section 572.137(a...). Within this specified compression corridor, the peak force, measured by the impact probe as defined in... midsagittal plane so that the impact point of the longitudinal centerline of the probe coincides with the...

49 CFR 572.10 - Limbs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of the forward edge of the seat. (3) Align the test probe specified in § 572.11(a) so that at impact...) Impact the knee with the test probe moving horizontally and parallel to the midsagittal plane at the specified velocity. (5) Guide the probe during impact so that it moves with no significant lateral, vertical...

49 CFR 572.10 - Limbs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of the forward edge of the seat. (3) Align the test probe specified in § 572.11(a) so that at impact...) Impact the knee with the test probe moving horizontally and parallel to the midsagittal plane at the specified velocity. (5) Guide the probe during impact so that it moves with no significant lateral, vertical...

49 CFR 572.10 - Limbs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of the forward edge of the seat. (3) Align the test probe specified in § 572.11(a) so that at impact...) Impact the knee with the test probe moving horizontally and parallel to the midsagittal plane at the specified velocity. (5) Guide the probe during impact so that it moves with no significant lateral, vertical...

49 CFR 572.174 - Thorax assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... assembled dummy (drawing 420-0000) (incorporated by reference, see § 572.170) is impacted by a test probe... this specified compression corridor, the peak force, measured by the impact probe as defined in section... midsagittal plane so that the impact point of the longitudinal centerline of the probe coincides with the...

49 CFR 572.134 - Thorax assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... completely assembled dummy (drawing 880105-000) is impacted by a test probe conforming to section 572.137(a...). Within this specified compression corridor, the peak force, measured by the impact probe as defined in... midsagittal plane so that the impact point of the longitudinal centerline of the probe coincides with the...

49 CFR 572.174 - Thorax assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... assembled dummy (drawing 420-0000) (incorporated by reference, see § 572.170) is impacted by a test probe... this specified compression corridor, the peak force, measured by the impact probe as defined in section... midsagittal plane so that the impact point of the longitudinal centerline of the probe coincides with the...

49 CFR 572.174 - Thorax assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... assembled dummy (drawing 420-0000) (incorporated by reference, see § 572.170) is impacted by a test probe... this specified compression corridor, the peak force, measured by the impact probe as defined in section... midsagittal plane so that the impact point of the longitudinal centerline of the probe coincides with the...

High-Velocity Impact Fragmentation of Projectiles Experimental Results

DTIC Science & Technology

2016-10-01

Program (JIMTP) Tube -Launched, Optically Tracked, Wire-Guided (TOW) 2B Insensitive Munitions (IM) Warhead effort. The referenced experiments were...conducted to determine the velocity reduction and fragmentation profile of barrier materials subjected to impact by the IM Fragment Impact (FI) test...9 LIST OF TABLES Table Title Page 1. Single Material Test Matrix

Dynamic Finite Element Predictions for Mars Sample Return Cellular Impact Test #4

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Billings, Marcus D.

2001-01-01

The nonlinear, transient dynamic finite element code, MSC.Dytran, was used to simulate an impact test of an energy absorbing Earth Entry Vehicle (EEV) that will impact without a parachute. EEVOs are designed to return materials from asteroids, comets, or planets for laboratory analysis on Earth. The EEV concept uses an energy absorbing cellular structure designed to contain and limit the acceleration of space exploration samples during Earth impact. The spherical shaped cellular structure is composed of solid hexagonal and pentagonal foam-filled cells with hybrid graphite-epoxy/Kevlar cell walls. Space samples fit inside a smaller sphere at the center of the EEVOs cellular structure. Pre-test analytical predictions were compared with the test results from a bungee accelerator. The model used to represent the foam and the proper failure criteria for the cell walls were critical in predicting the impact loads of the cellular structure. It was determined that a FOAM1 model for the foam and a 20% failure strain criteria for the cell walls gave an accurate prediction of the acceleration pulse for cellular impact.

Impact force as a scaling parameter

NASA Technical Reports Server (NTRS)

Poe, Clarence C., Jr.; Jackson, Wade C.

1994-01-01

The Federal Aviation Administration (FAR PART 25) requires that a structure carry ultimate load with nonvisible impact damage and carry 70 percent of limit flight loads with discrete damage. The Air Force has similar criteria (MIL-STD-1530A). Both civilian and military structures are designed by a building block approach. First, critical areas of the structure are determined, and potential failure modes are identified. Then, a series of representative specimens are tested that will fail in those modes. The series begins with tests of simple coupons, progresses through larger and more complex subcomponents, and ends with a test on a full-scale component, hence the term 'building block.' In order to minimize testing, analytical models are needed to scale impact damage and residual strength from the simple coupons to the full-scale component. Using experiments and analysis, the present paper illustrates that impact damage can be better understood and scaled using impact force than just kinetic energy. The plate parameters considered are size and thickness, boundary conditions, and material, and the impact parameters are mass, shape, and velocity.

Detection of impact damage on thermal protection systems using thin-film piezoelectric sensors for integrated structural health monitoring

NASA Astrophysics Data System (ADS)

Na, Jeong K.; Kuhr, Samuel J.; Jata, Kumar V.

2008-03-01

Thermal Protection Systems (TPS) can be subjected to impact damage during flight and/or during ground maintenance and/or repair. AFRL/RXLP is developing a reliable and robust on-board sensing/monitoring capability for next generation thermal protection systems to detect and assess impact damage. This study was focused on two classes of metallic thermal protection tiles to determine threshold for impact damage and develop sensing capability of the impacts. Sensors made of PVDF piezoelectric film were employed and tested to evaluate the detectability of impact signals and assess the onset or threshold of impact damage. Testing was performed over a range of impact energy levels, where the sensors were adhered to the back of the specimens. The PVDF signal levels were analyzed and compared to assess damage, where digital microscopy, visual inspection, and white light interferometry were used for damage verification. Based on the impact test results, an assessment of the impact damage thresholds for each type of metallic TPS system was made.

The Impact of Scholastic Instrumental Music and Scholastic Chess Study on the Standardized Test Scores of Students in Grades Three, Four, and Five

ERIC Educational Resources Information Center

Martinez, Edwin E.

2012-01-01

This study examines the impact of instrumental music study and group chess lessons on the standardized test scores of suburban elementary public school students (grades three through five) in Levittown, New York. The study divides the students into the following groups and compares the standardized test scores of each: a) instrumental music…

Test Candidates' Attitudes and Their Relationship to Demographic and Experiential Variables: The Case of Overseas Trained Teachers in NSW, Australia

ERIC Educational Resources Information Center

Murray, Jill C.; Riazi, A. Mehdi; Cross, Judith L.

2012-01-01

One measure of the impact of a high-stakes test is the attitudes that test takers hold towards it. It has been suggested that positive attitudes produce beneficial effects while real or anticipated negative experiences can result in the development of attitudes that erode confidence and potentially impact negatively on performance. This study…

The Impact of Test Dimensionality, Common-Item Set Format, and Scale Linking Methods on Mixed-Format Test Equating

ERIC Educational Resources Information Center

Öztürk-Gübes, Nese; Kelecioglu, Hülya

2016-01-01

The purpose of this study was to examine the impact of dimensionality, common-item set format, and different scale linking methods on preserving equity property with mixed-format test equating. Item response theory (IRT) true-score equating (TSE) and IRT observed-score equating (OSE) methods were used under common-item nonequivalent groups design.…

An Empirical Investigation of the Potential Impact of Item Misfit on Test Scores. Research Report. ETS RR-17-60

ERIC Educational Resources Information Center

Kim, Sooyeon; Robin, Frederic

2017-01-01

In this study, we examined the potential impact of item misfit on the reported scores of an admission test from the subpopulation invariance perspective. The target population of the test consisted of 3 major subgroups with different geographic regions. We used the logistic regression function to estimate item parameters of the operational items…

Instrumented impact testing of kenaf fiber reinforced polypropylene composites: effects of temperature and composition

Treesearch

Craig Merrill Clemons; Anand R. Sanadi

2007-01-01

An instrumented Izod test was used to investigate the effects of fiber content, coupling agent, and temperature on the impact performance of kenaf fiber reinforced polypropylene (PP). Composites containing 0-60% (by weight) kenaf fiber and 0 or 2% maleated polypropylene (MAPP) and PP/wood flour composites were tested at room temperature and between -50 °C and +...

The Risk of Adverse Impact in Selections Based on a Test with Known Effect Size

ERIC Educational Resources Information Center

De Corte, Wilfried; Lievens, Filip

2005-01-01

The authors derive the exact sampling distribution function of the adverse impact (AI) ratio for single-stage, top-down selections using tests with known effect sizes. Subsequently, it is shown how this distribution function can be used to determine the risk that a future selection decision on the basis of such tests will result in an outcome that…

49 CFR 572.200 - Instrumentation and test conditions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... a minimum mass moment of inertia of 3646 kg-cm2. (b) The test probe for the lateral abdomen impact... and it has a minimum mass moment of inertia of 3646 kg-cm2. (c) The test probe for the pelvis-iliac... impact surface 50.8 × 88.9 mm for a depth of at least 76 mm and a minimum mass moment of inertia of 5000...

49 CFR 572.200 - Instrumentation and test conditions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... a minimum mass moment of inertia of 3646 kg-cm2. (b) The test probe for the lateral abdomen impact... and it has a minimum mass moment of inertia of 3646 kg-cm2. (c) The test probe for the pelvis-iliac... impact surface 50.8 × 88.9 mm for a depth of at least 76 mm and a minimum mass moment of inertia of 5000...

Testing of small and large sign support systems FOIL test number : 92F017

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92F017. The vehicle used for this te...

46 CFR 54.05-5 - Toughness test specimens.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Toughness test specimens. 54.05-5 Section 54.05-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Toughness Tests § 54.05-5 Toughness test specimens. (a) Charpy V-notch impact tests. Where required, Charpy V-notch tests shall be conducted in accordanc...

Testing of small and large sign support systems FOIL test number : 92F026

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92F026. The vehicle used for this te...

Testing of small and large sign support systems FOIL test number : 92F018

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92F018. The vehicle used for this te...

Testing of small and large sign support systems FOIL test number : 92F015

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92F015. The vehicle used for these t...

Testing of small and large sign support systems FOIL test number : 92F012

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92F012. The vehicle used for these t...

Testing of small and large sign support systems FOIL test number : 92F023

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92F023. The vehicle used for this te...

Testing of small and large sign support systems FOIL test number : 92F019

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92F019. The vehicle used for this te...

Counseling and Testing: What Counselors Need to Know about State Laws on Assessment and Testing

ERIC Educational Resources Information Center

Naugle, Kim A.

2009-01-01

This article discusses testing in counseling, the history of psychology's attempts to restrict access to testing, and the potential impact on the public. Counselors are encouraged to obtain appropriate training in assessment and to understand that testing is not only consistent with fair testing policies but also essential for ethical practice.…

Experimental Investigation of the Shuttle Transportation System Composite Overwrapped Pressure Vessels for Stress Rupture Life

NASA Technical Reports Server (NTRS)

Greene, Nathanael; Saulsberry, Regor; Yoder, Tommy; Forsyth, Brad; Carillo, Marlene; Thesken, John

2006-01-01

A viewgraph presentation describing stress rupture testing on Composite Overwrapped Pressure Vessels (COPV) is shown. The topics include: 1) Purpose for Testing; 2) NASA WSTF COPV Test Program; 3) NASA WSTF Test Facilities; 4) COPV Impact Study; 5) Fluids Compatibility Testing; 6) Stress Rupture Testing; and 7) COPV Lifting.

Testing of small and large sign support systems FOIL test number : 92F014

DOT National Transportation Integrated Search

1994-07-01

This test report contains the results of a crash test performed at the Federal Outdoor Impact Laboratory (FOIL) in McLean, Virginia. The test was performed on a small sign support system at 20 mi/h (8.9 m/s), test 92F014. The vehicle used for these t...

Spin Testing for Durability Began on a Self-Tuning Impact Damper for Turbomachinery Blades

NASA Technical Reports Server (NTRS)

Duffy, Kirsten; Mehmed, Oral

2003-01-01

NASA and Pratt & Whitney will collaborate under a Space Act Agreement to perform spin testing of the impact damper to verify damping effectiveness and durability. Pratt & Whitney will provide the turbine blade and damper hardware for the tests. NASA will provide the facility and perform the tests. Effectiveness and durability will be investigated during and after sustained sweeps of rotor speed through resonance. Tests of a platform wedge damper are also planned to compare its effectiveness with that of the impact damper. Results from baseline tests without dampers will be used to measure damping effectiveness. The self-tuning impact damper combines two damping methods-the tuned mass damper and the impact damper. It consists of a ball located within a cavity in the blade. This ball rolls back and forth on a spherical trough under centrifugal load (tuned mass damper) and can strike the walls of the cavity (impact damper). The ball s rolling natural frequency is proportional to the rotor speed and can be designed to follow an engine-order line (integer multiple of rotor speed). Aerodynamic forcing frequencies typically follow these engineorder lines, and a damper tuned to the engine order will most effectively reduce blade vibrations when the resonant frequency equals the engine-order forcing frequency. This damper has been tested in flat plates and turbine blades in the Dynamic Spin Facility. During testing, a pair of plates or blades rotates in vacuum. Excitation is provided by one of three methods--eddy-current engine-order excitation (ECE), electromechanical shakers, and magnetic bearing excitation. The eddy-current system consists of magnets located circumferentially around the rotor. As a blade passes a magnet, a force is imparted on the blade. The number of magnets used can be varied to change the desired engine order of the excitation. The magnets are remotely raised or lowered to change the magnitude of the force on the blades. The other two methods apply force to the rotating shaft itself at frequencies independent of the rotor speed. During testing, blade vibration is monitored with strain gauges and laser displacement probes.

Impact resistance and prescription compliance with AS/NZS 1337.6:2010.

PubMed

Dain, Stephen J; Ngo, Thao P T; Cheng, Brian B

2013-09-01

Australian/New Zealand Standard 1337.6 deals with prescription eye protection and has been in place since 2007. There have been many standards marking licences granted since then. The issue of the worst-case situations for assessment in a certification scheme, in particular -1.50 m(-1) lenses, has been the subject of discussion in Standards Australia/Standards New Zealand Committee SF-006. Given that a body of data from testing exists, this was explored to advise the Committee. Data from testing 40 sets of prescription eye protectors were analysed retrospectively for compliance with the impact and refractive power requirements in 2010-11. The testing had been carried out according to the methods of AS/NZS 1337.6:2007 under the terms and conditions of the accreditation of the Optics & Radiometry Laboratory by the National Association of Testing Authorities. No eye protector failed the low-impact resistance test. Failure rates of 1.6 per cent (two of the 40 sets) to the medium impact test and 1.6 per cent (three of the sets) to the medium impact test in the elevated temperature stability test were seen. These are too small for useful statistical analysis. Only -1.50 m(-1) lenses were in all failing sets and these lenses were over-represented in the failures and borderlines, especially compared with the +1.50 D lenses. Failures in prismatic power were equally distributed over all prescriptions. This over-representation of -1.50 m(-1) lenses was not related to the ocular/lens material or to the company manufacturing the eye protectors. The proposal is made that glazing lenses tightly to ensure they are retained in the frame on impact may result in unwanted refractive power in those lenses most prone to flex. These data support the proposal that -1.50 m(-1) lenses should form part of a worst-case testing regime in a certification scheme. © 2012 The Authors. Clinical and Experimental Optometry © 2012 Optometrists Association Australia.

Using Modeling and Simulation to Complement Testing for Increased Understanding of Weapon Subassembly Response.

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

Wong, Michael K.; Davidson, Megan

As part of Sandia’s nuclear deterrence mission, the B61-12 Life Extension Program (LEP) aims to modernize the aging weapon system. Modernization requires requalification and Sandia is using high performance computing to perform advanced computational simulations to better understand, evaluate, and verify weapon system performance in conjunction with limited physical testing. The Nose Bomb Subassembly (NBSA) of the B61-12 is responsible for producing a fuzing signal upon ground impact. The fuzing signal is dependent upon electromechanical impact sensors producing valid electrical fuzing signals at impact. Computer generated models were used to assess the timing between the impact sensor’s response to themore » deceleration of impact and damage to major components and system subassemblies. The modeling and simulation team worked alongside the physical test team to design a large-scale reverse ballistic test to not only assess system performance, but to also validate their computational models. The reverse ballistic test conducted at Sandia’s sled test facility sent a rocket sled with a representative target into a stationary B61-12 (NBSA) to characterize the nose crush and functional response of NBSA components. Data obtained from data recorders and high-speed photometrics were integrated with previously generated computer models in order to refine and validate the model’s ability to reliably simulate real-world effects. Large-scale tests are impractical to conduct for every single impact scenario. By creating reliable computer models, we can perform simulations that identify trends and produce estimates of outcomes over the entire range of required impact conditions. Sandia’s HPCs enable geometric resolution that was unachievable before, allowing for more fidelity and detail, and creating simulations that can provide insight to support evaluation of requirements and performance margins. As computing resources continue to improve, researchers at Sandia are hoping to improve these simulations so they provide increasingly credible analysis of the system response and performance over the full range of conditions.« less

Crash simulation of UNS electric vehicle under frontal front impact

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

Susilo, D. D., E-mail: djoksus-2010@yahoo.com; Lukamana, N. I., E-mail: n.indra.lukmana@gmail.com; Budiana, E. P., E-mail: budiana.e@gmail.com

Sebelas Maret University has been developing an Electric Vehicle namely SmarT-EV UNS. The main structure of the car are chasis and body. The chasis is made from steel and the body is made from fiberglass composite. To ensure the safety of the car, both static and dynamic tests were carried out to these structures, including their materials, like: tensile test, bending test, and impact test. Another test needed by this vehicle is crashworthiness test. To perform the test, it is needed complex equipments and it is quite expensive. Another way to obtain vehicle crashworthiness behaviour is by simulate it. Themore » purpose of this study was to simulate the response of the Smart-EV UNS electric vehicle main structure when crashing rigid barrier from the front. The crash simulation was done in according to the NHTSA (National Highway Traffic Safety Administration) within the speed of the vehicle of 35 mph. The UNS Electric Vehicle was modelled using SolidWorks software, and the simulation process was done by finite element method using ANSYS software. The simulation result showed that the most internal impact energy was absorbed by chassis part. It absorbed 76.2% of impact energy, then the base absorbed 11.3 %, while the front body absorbed 2.5 %, and the rest was absorbed by fender, hood, and other parts.« less

Service-learning's impact on dental students' attitude towards community service.

PubMed

Coe, J M; Best, A M; Warren, J J; McQuistan, M R; Kolker, J L; Isringhausen, K T

2015-08-01

This study evaluated service-learning programme's impact on senior dental students' attitude towards community service at Virginia Commonwealth University (VCU) School of Dentistry. Experience gained through service-learning in dental school may positively impact dental students' attitude towards community service that will eventually lead into providing care to the underserved. Two surveys (pre- and post-test) were administered to 105 senior dental students. For the first survey (post-test), seventy-six students of 105 responded and reported their attitude towards community service immediately after the service-learning programme completion. Three weeks later, 56 students of the 76 responded to the second survey (retrospective pre-test) and reported their recalled attitude prior to the programme retrospectively. A repeated-measure mixed-model analysis indicated that overall there was improvement between pre-test and post-test. Scales of connectedness, normative helping behaviour, benefits, career benefits and intention showed a significant pre-test and post-test difference. An association between attitude towards community service and student characteristics such as age, gender, ethnicity and volunteer activity was also examined. Only ethnicity showed an overall significant difference. White dental students appear to have a differing perception of the costs of community service. The service-learning programme at VCU School of Dentistry has positively impacted senior dental students' attitude towards community service. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Service-learning’s Impact on Dental Students’ Attitude toward Community Service

PubMed Central

Coe, J. M.; Best, A. M.; Warren, J. J.; McQuistan, M. R.; Kolker, J. L.; Isringhausen, K. T.

2014-01-01

Introduction This study evaluated service-learning program’s impact on senior dental students’ attitude toward community service at Virginia Commonwealth University (VCU) School of Dentistry. Experience gained through service-learning in dental school may positively impact dental students’ attitude toward community service that will eventually lead into providing care to the underserved. Materials and methods Two surveys (pre and post-test) were administered to 105 senior dental students. For the first survey (post-test), seventy six students out of 105 responded and reported their attitude toward community service immediately after the service-learning program completion. Three weeks later, fifty six students out of the 76 responded to the second survey (retrospective pre-test) and reported their recalled attitude prior to the program retrospectively. Results A repeated-measure mixed-model analysis indicated that overall there was improvement between pre-test and post-test. Scales of connectedness, normative helping behavior, benefits1, career benefits, and intention showed a significant pre-test and post-test difference. An association between attitude toward community service and student characteristics such as age, gender, ethnicity, and volunteer activity was also examined. Only ethnicity showed an overall significant difference. White dental students appear to have a differing perception of the costs of community service. Conclusions The service-learning program at VCU School of Dentistry has positively impacted senior dental students’ attitude toward community service. PMID:25142286

Crash test rating and likelihood of major thoracoabdominal injury in motor vehicle crashes: the new car assessment program side-impact crash test, 1998-2010.

PubMed

Figler, Bradley D; Mack, Christopher D; Kaufman, Robert; Wessells, Hunter; Bulger, Eileen; Smith, Thomas G; Voelzke, Bryan

2014-03-01

The National Highway Traffic Safety Administration's New Car Assessment Program (NCAP) implemented side-impact crash testing on all new vehicles since 1998 to assess the likelihood of major thoracoabdominal injuries during a side-impact crash. Higher crash test rating is intended to indicate a safer car, but the real-world applicability of these ratings is unknown. Our objective was to determine the relationship between a vehicle's NCAP side-impact crash test rating and the risk of major thoracoabdominal injury among the vehicle's occupants in real-world side-impact motor vehicle crashes. The National Automotive Sampling System Crashworthiness Data System contains detailed crash and injury data in a sample of major crashes in the United States. For model years 1998 to 2010 and crash years 1999 to 2010, 68,124 occupants were identified in the Crashworthiness Data System database. Because 47% of cases were missing crash severity (ΔV), multiple imputation was used to estimate the missing values. The primary predictor of interest was the occupant vehicle's NCAP side-impact crash test rating, and the outcome of interest was the presence of major (Abbreviated Injury Scale [AIS] score ≥ 3) thoracoabdominal injury. In multivariate analysis, increasing NCAP crash test rating was associated with lower likelihood of major thoracoabdominal injury at high (odds ratio [OR], 0.8; 95% confidence interval [CI], 0.7-0.9; p < 0.01) and medium (OR, 0.9; 95% CI, 0.8-1.0; p < 0.05) crash severity (ΔV), but not at low ΔV (OR, 0.95; 95% CI, 0.8-1.2; p = 0.55). In our model, older age and absence of seat belt use were associated with greater likelihood of major thoracoabdominal injury at low and medium ΔV (p < 0.001), but not at high ΔV (p ≥ 0.09). Among adults in model year 1998 to 2010 vehicles involved in medium and high severity motor vehicle crashes, a higher NCAP side-impact crash test rating is associated with a lower likelihood of major thoracoabdominal trauma. Epidemiologic study, level III.

40 CFR 51.371 - On-road testing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false On-road testing. 51.371 Section 51.371... PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Inspection/Maintenance Program Requirements § 51.371 On-road testing. On-road testing is defined as testing of vehicles for conditions impacting the...

40 CFR 1066.830 - Supplemental Federal Test Procedures; overview.

Code of Federal Regulations, 2014 CFR

2014-07-01

... driving and a sequence of vehicle operation that accounts for the impact of the vehicle's air conditioner...) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Exhaust Emission Test Procedures for Motor Vehicles... results from the aggressive driving test element (§ 1066.831), the air conditioning test element (§ 1066...

49 CFR 173.57 - Acceptance criteria for new explosives.

Code of Federal Regulations, 2010 CFR

2010-10-01

... must be subjected to the Drop Weight Impact Sensitivity Test (Test Method 3(a)(i)), the Friction... substance has a friction sensitiveness equal to or greater than that of dry pentaerythrite tetranitrate (PETN) when tested in the Friction Sensitivity Test; (4) The substance fails to pass the test criteria...

LEARNING AND MEMORY TESTS IN DEVELOPMENTAL NEUROTOXICITY TESTING: A CROSS-LABORATORY COMPARISON OF CONTROL DATA.

EPA Science Inventory

The US EPA Developmental Neurotoxicity (DNT) Study Test Guideline (OPPTS 870.6300) calls for functional tests to assess the impact of chemicals on cognitive function in offspring following maternal exposure. A test of associative learning and memory is to be conducted around th...

Staged collision and damage data. Volume 1: Report for accident reconstruction of thirty (30) test vehicles

NASA Astrophysics Data System (ADS)

Hand, D. H.

1981-01-01

The test vehicles were impacted tested for compliance with FMVSS 212/219/301-75. As a parallel nonconflicting effort, the test vehicles were instrumented with accelerometers to measure vehicle accelerator resultants.

Blunt Impact Tests of Retired Passenger Locomotive Fuel Tanks

DOT National Transportation Integrated Search

2017-08-01

The Transportation Technology Center, Inc. conducted impact tests on three locomotive fuel tanks as part of the Federal Railroad Administrations locomotive fuel tank crashworthiness improvement program. Three fuel tanks, two from EMD F40PH locomot...

Rail-car impact tests with steel coil : car crush

DOT National Transportation Integrated Search

2003-04-22

Two grade-crossing impact tests were conducted in June 2002 at the Federal Railroad Administration's (FRA's) Transportation Technology Center in Pueblo, Colorado as part of the FRA's research into passenger equipment crashworthiness. In both of these...

Blunt impact tests of retired passenger locomotive fuel tanks

DOT National Transportation Integrated Search

2017-08-01

The Transportation Technology Center, Inc. conducted impact tests on three locomotive fuel tanks as part of the Federal Railroad Administrations locomotive fuel tank crashworthiness improvement program. Three fuel tanks, two from EMD F40PH locomot...

Special Form Testing of Sealed Source Encapsulation for High-Alpha-Activity Actinide Materials

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

Martinez, Oscar A

In the United States all transportation of radioactive material is regulated by the U.S. Department of Transportation (DOT). Beginning in 2008 a new type of sealed-source encapsulation package was developed and tested by Oak Ridge National Laboratory (ORNL). These packages contain high-alpha-activity actinides and are regulated and transported in accordance with the requirements for DOT Class 7 hazardous material. The DOT provides specific regulations pertaining to special form encapsulation designs. The special form designation indicates that the encapsulated radioactive contents have a very low probability of dispersion even when subjected to significant structural events. The special form designs have beenmore » shown to simplify the delivery, transport, acceptance, and receipt processes. It is intended for these sealed-source encapsulations to be shipped to various facilities making it very advantageous for them to be certified as special form. To this end, DOT Certificates of Competent Authority (CoCAs) have been sought for the design suitable for containing high-alpha-activity actinide materials. This design consists of the high-alpha-activity material encapsulated within a triangular zirconia canister, referred to as a ZipCan, tile that is then enclosed by a spherical shell. The spherical shell design, with ZipCan tile inside, was tested for compliance with the special form regulations found in 49 CFR 173.469. The spherical enclosure was subjected to 9-m impact, 1 m percussion, and 10-minute thermal tests at the Packaging Evaluation Facility located at the National Transportation Research Center in Knoxville, TN USA and operated by ORNL. Before and after each test, the test units were subjected to a helium leak check and a bubble test. The ZipCan tiles and core were also subjected to the tests required for ISO 2919:2012(E), including a Class IV impact test and heat test and subsequently subjected to helium leakage rate tests [49 CFR 173.469(a)(4)(i)]. The impact-tile test unit contained a nonradioactive surrogate; however, the thermal test unit contained a radioactive source. This paper describes the regulatory special form tests and presents detailed impact and leak test results that demonstrate that the sealed source encapsulation designs satisfy the regulatory tests.« less

Study of austenitic stainless steel welded with low alloy steel filler metal. [tensile and impact strength tests

NASA Technical Reports Server (NTRS)

Burns, F. A.; Dyke, R. A., Jr.

1979-01-01

The tensile and impact strength properties of 316L stainless steel plate welded with low alloy steel filler metal were determined. Tests were conducted at room temperature and -100 F on standard test specimens machined from as-welded panels of various chemical compositions. No significant differences were found as the result of variations in percentage chemical composition on the impact and tensile test results. The weldments containing lower chromium and nickel as the result of dilution of parent metal from the use of the low alloy steel filler metal corroded more severely in a marine environment. The use of a protective finish, i.e., a nitrile-based paint containing aluminum powder, prevented the corrosive attack.

The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

NASA Astrophysics Data System (ADS)

Minet, Valentine; Alpan, Lutfiye; Mullier, François; Toussaint, Olivier; Lucas, Stéphane; Dogné, Jean-Michel; Laloy, Julie

2015-07-01

Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

Thermal Management Coating As Thermal Protection System for Space Transportation System

NASA Technical Reports Server (NTRS)

Kaul, Raj; Stuckey, C. Irvin

2003-01-01

This paper presents viewgraphs on the development of a non-ablative thermal management coating used as the thermal protection system material for space shuttle rocket boosters and other launch vehicles. The topics include: 1) Coating Study; 2) Aerothermal Testing; 3) Preconditioning Environments; 4) Test Observations; 5) Lightning Strike Test Panel; 6) Test Panel After Impact Testing; 7) Thermal Testing; and 8) Mechanical Testing.

An integrated draft gear model with the consideration of wagon body structural characteristics

NASA Astrophysics Data System (ADS)

Chang, Gao; Liangliang, Yang; Weihua, Ma; Min, Zhang; Shihui, Luo

2018-03-01

With the increase of railway wagon axle load and the growth of marshalling quantity, the problem caused by impact and vibration of vehicles is increasingly serious, which leads to the damage of vehicle structures and the components. In order to improve the reliability of longitudinal connection model for vehicle impact tests, a new railway wagon longitudinal connection model was developed to simulate and analyse vehicle impact tests. The new model is based on characteristics of longitudinal force transmission for vehicles and parts. In this model, carbodies and bogies were simplified to a particle system that can vibrate in the longitudinal direction, which corresponded to a stiffness-damping vibration system. The model consists of three sub-models, that is, coupler and draft gear sub-model, centre plate sub-model and carbody structure sub-model. Compared with conventional draft gear models, the new model was proposed with geometrical and mechanical relations of friction draft gears considered and with behaviours of sticking, sliding and impact between centre plate and centre bowl added. Besides, virtual springs between discrete carbodies were built to describe the structural deformation of carbody. A computation program for longitudinal dynamics based on vehicle impact tests was accomplished to simulate. Comparisons and analyses regarding the train dynamics outputs and vehicle impact tests were conducted. Simulation results indicate that the new wagon longitudinal connection model can provide a practical application environment for wagons, and the outputs of vehicle impact tests agree with those of field tests. The new model can also be used to study on longitudinal vibrations of different vehicles, of carbody and bogie, and of carbody itself.

Environmental assessment of the 40 kilowatt fuel cell system field test operation

NASA Technical Reports Server (NTRS)

Bollenbacher, G.

1982-01-01

This environmental assessment examines the potential environmental consequences, both adverse and beneficial, of the 40 kW fuel cell system system field test operation. The assessment is of necessity generic in nature since actual test sites were not selected. This assessment provides the basis for determining the need for an environmental impact statement. In addition, this assessment provides siting criteria to avoid or minimize negative environmental impacts and standards for determining candidate test sites, if any, for which site specific assessments may be required.

Design and Analysis of Tooth Impact Test Rig for Spur Gear

NASA Astrophysics Data System (ADS)

Ghazali, Wafiuddin Bin Md; Aziz, Ismail Ali Bin Abdul; Daing Idris, Daing Mohamad Nafiz Bin; Ismail, Nurazima Binti; Sofian, Azizul Helmi Bin

2016-02-01

This paper is about the design and analysis of a prototype of tooth impact test rig for spur gear. The test rig was fabricated and analysis was conducted to study its’ limitation and capabilities. The design of the rig is analysed to ensure that there will be no problem occurring during the test and reliable data can be obtained. From the result of the analysis, the maximum amount of load that can be applied, the factor of safety of the machine, the stresses on the test rig parts were determined. This is important in the design consideration of the test rig. The materials used for the fabrication of the test rig were also discussed and analysed. MSC Nastran Patran software was used to analyse the model, which was designed by using SolidWorks 2014 software. Based from the results, there were limitations found from the initial design and the test rig design needs to be improved in order for the test rig to operate properly.

Routine admission laboratory testing for general medical patients.

PubMed

Hubbell, F A; Frye, E B; Akin, B V; Rucker, L

1988-06-01

We evaluated the usefulness of commonly ordered routine admission laboratory tests in 301 patients admitted consecutively to the internal medicine wards of a university teaching hospital. Using a consensus analysis approach, three Department of Medicine faculty members reviewed the charts of admitted patients to determine the impact of the test results on patient care. The evaluated tests were the urinalysis, hematocrit, white blood cell count, platelet count, six-factor automated multiple analysis (serum sodium, potassium, chloride, bicarbonate, glucose, and blood urea nitrogen), prothrombin time, partial thromboplastin time, chest x-ray, and electrocardiogram. Forty-five percent of the 3,684 tests were ordered for patients without recognizable medical indications. Twelve percent of these routine tests were abnormal, 5% led to additional laboratory testing, but only 0.5% led to change in the treatment of patients. We conclude that the impact of routine admission laboratory testing on patient care is very small and that there is little justification for ordering tests solely because of hospital admission.

Galileo battery testing and the impact of test automation

NASA Technical Reports Server (NTRS)

Pertuch, W. T.; Dils, C. T.

1985-01-01

Test complexity, changes of test specifications, and the demand for tight control of tests led to the development of automated testing used for Galileo and other projects. The use of standardized interfacing, i.e., IEEE-488, with desktop computers and test instruments, resulted in greater reliability, repeatability, and accuracy of both control and data reporting. Increased flexibility of test programming has reduced costs by permitting a wide spectrum of test requirements at one station rather than many stations.

Implementing statistical analysis in multi-channel acoustic impact-echo testing of concrete bridge decks: Determining thresholds for delamination detection

NASA Astrophysics Data System (ADS)

Hendricks, Lorin; Spencer Guthrie, W.; Mazzeo, Brian

2018-04-01

An automated acoustic impact-echo testing device with seven channels has been developed for faster surveying of bridge decks. Due to potential variations in bridge deck overlay thickness, varying conditions between testing passes, and occasional imprecise equipment calibrations, a method that can account for variations in deck properties and testing conditions was necessary to correctly interpret the acoustic data. A new methodology involving statistical analyses was therefore developed. After acoustic impact-echo data are collected and analyzed, the results are normalized by the median for each channel, a Gaussian distribution is fit to the histogram of the data, and the Kullback-Leibler divergence test or Otsu's method is then used to determine the optimum threshold for differentiating between intact and delaminated concrete. The new methodology was successfully applied to individual channels of previously unusable acoustic impact-echo data obtained from a three-lane interstate bridge deck surfaced with a polymer overlay, and the resulting delamination map compared very favorably with the results of a manual deck sounding survey.