National automotive sampling system crashworthiness data system 1994-1996
DOT National Transportation Integrated Search
1999-10-01
This report focuses attention on occupants of those passenger vehicles that were towed from : the crash scene. NHTSA's National Automotive Sampling System (NASS)/ Crashworthiness : Data System (CDS) collects detailed information on towed passenger ve...
DOT National Transportation Integrated Search
2008-01-01
Comparing the 1988-2007 files with files from years prior to 1988 is not recommended. The : principal attributes of the NASS CDS 1988-2007 files include: focusing on crashes involving : automobiles and automobile derivatives, light trucks and vans wi...
Potential crashworthiness benefits to general aviation from Indianapolis Motor Speedway technology.
Jennings, R T; Mohler, S R
1988-01-01
General aviation crashworthiness can potentially benefit from certain advances being accomplished by the automobile industry. Progressive improvements in crash protection technology, as documented by a dramatic reduction in crash injuries and fatalities at the Indianapolis Motor Speedway, reflect improved crashworthiness. The speeds of survivable general aviation aircraft impacts are in the range of the Indianapolis Motor Speedway crashes (200-220 mph). This paper relates the declining crash death rates at Indy by decade versus the increase in speeds. The continuous rise in speeds has prompted the development of new crashworthy designs and driver protection equipment. Crashworthiness improvements include crushable surrounding structures, high-grade restraint systems, protective head gear, fire resistant clothing, break-away structural components, and a "protective cocoon" concept. Adaptation of selected advances in crashworthiness design and operations accomplished at the Indianapolis Motor Speedway to the next generation of general aviation aircraft should provide significant dividends in survival of air crashes.
Time-dependent crashworthiness of polyurethane foam
NASA Astrophysics Data System (ADS)
Basit, Munshi Mahbubul; Cheon, Seong Sik
2018-05-01
Time-dependent stress-strain relationship as well as crashworthiness of polyurethane foam was investigated under constant impact energy with different velocities, considering inertia and strain-rate effects simultaneously during the impact testing. Even though the impact energies were same, the percentage in increase in densification strain due to higher impact velocities was found, which yielded the wider plateau region, i.e. growth in crashworthiness. This phenomenon is analyzed by the microstructure of polyurethane foam obtained from scanning electron microscopy. The equations, coupled with the Sherwood-Frost model and the impulse-momentum theory, were employed to build the constitutive equation of the polyurethane foam and calculate energy absorption capacity of the foam. The nominal stress-strain curves obtained from the constitutive equation were compared with results from impact tests and were found to be in good agreement. This study is dedicated to guiding designer use polyurethane foam in crashworthiness structures such as an automotive bumper system by providing crashworthiness data, determining the crush mode, and addressing a mathematical model of the crashworthiness.
The Role Of Driver Inattention In Crashes; New Statistics From The 1995 Crashworthiness Data System
DOT National Transportation Integrated Search
1996-08-08
INTELLIGENT VEHICLE INITIATIVE OR IVI : IN 1995, NHTSA BEGAN EMPLOYING THE CRASHWORTHINESS DATA SYSTEM (CDS) TO OBTAIN MORE IN-DEPTH INFORMATION ON DRIVER INATTENTION-RELATED CRASH CAUSES, INCLUDING DROWSINESS AND MANY FORMS OF DISTRACTION. CDS IS PO...
49 CFR 229.209 - Alternative locomotive crashworthiness designs.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Alternative locomotive crashworthiness designs... Locomotive Crashworthiness Design Requirements § 229.209 Alternative locomotive crashworthiness designs. (a... locomotive crashworthiness designs which are not consistent with any FRA-approved locomotive crashworthiness...
49 CFR 229.209 - Alternative locomotive crashworthiness designs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Alternative locomotive crashworthiness designs... Locomotive Crashworthiness Design Requirements § 229.209 Alternative locomotive crashworthiness designs. (a... locomotive crashworthiness designs which are not consistent with any FRA-approved locomotive crashworthiness...
49 CFR 229.209 - Alternative locomotive crashworthiness designs.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Alternative locomotive crashworthiness designs... Locomotive Crashworthiness Design Requirements § 229.209 Alternative locomotive crashworthiness designs. (a... locomotive crashworthiness designs which are not consistent with any FRA-approved locomotive crashworthiness...
49 CFR 229.209 - Alternative locomotive crashworthiness designs.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Alternative locomotive crashworthiness designs... Locomotive Crashworthiness Design Requirements § 229.209 Alternative locomotive crashworthiness designs. (a... locomotive crashworthiness designs which are not consistent with any FRA-approved locomotive crashworthiness...
NASA Astrophysics Data System (ADS)
Xia, Liang; Liu, Weiguo; Lv, Xiaojiang; Gu, Xianguang
2018-04-01
The structural crashworthiness design of vehicles has become an important research direction to ensure the safety of the occupants. To effectively improve the structural safety of a vehicle in a frontal crash, a system methodology is presented in this study. The surrogate model of Online support vector regression (Online-SVR) is adopted to approximate crashworthiness criteria and different kernel functions are selected to enhance the accuracy of the model. The Online-SVR model is demonstrated to have the advantages of solving highly nonlinear problems and saving training costs, and can effectively be applied for vehicle structural crashworthiness design. By combining the non-dominated sorting genetic algorithm II and Monte Carlo simulation, both deterministic optimization and reliability-based design optimization (RBDO) are conducted. The optimization solutions are further validated by finite element analysis, which shows the effectiveness of the RBDO solution in the structural crashworthiness design process. The results demonstrate the advantages of using RBDO, resulting in not only increased energy absorption and decreased structural weight from a baseline design, but also a significant improvement in the reliability of the design.
Ha, D; Bertocci, G; Deemer, E; van Roosmalen, L; Karg, P
2000-01-01
Automotive seats are tested for compliance with federal motor vehicle safety standards (FMVSS) to assure safety during impact. Many wheelchair users rely upon their wheelchairs to serve as vehicle seats. However, the crashworthiness of these wheelchairs during impact is often unknown. This study evaluated the crashworthiness of five combinations of wheelchair back support surfaces and attachment hardware using a static test procedure simulating crash loading conditions. The crashworthiness was tested by applying a simulated rearward load to each seat-back system. The magnitude of the applied load was established through computer simulation and biodynamic calculations. None of the five tested wheelchair back supports withstood the simulated crash loads. All failures were associated with attachment hardware.
Association between weight and risk of crash-related injuries for children in child restraints.
Zonfrillo, Mark R; Elliott, Michael R; Flannagan, Carol A; Durbin, Dennis R
2011-12-01
To determine the association between weight and the risk of injury in motor vehicle crashes (MVCs) for children 1 through 8 years of age who were using child restraints. This was a cross-sectional study of children 1 to 8 years of age in MVCs, in which cases from the National Automotive Sampling System Crashworthiness Data System were used. Abbreviated Injury Scale scores of ≥2 indicated clinically significant injuries. The National Automotive Sampling System Crashworthiness Data System study sample included 650 children 1 to 5 years of age in forward-facing child restraints who weighed 20 to 65 lb and 344 children 3 to 8 years of age in belt-positioning booster seats who weighed 30 to 100 lb. With adjustment for seating position, type of vehicle, direction of impact, crash severity, and vehicle model year, there was no association between absolute weight and clinically significant injuries in either age group (odds ratio: 1.17 [95% confidence interval: 0.96-1.42] for children 1-5 years of age in forward-facing child restraints and 1.22 [95% confidence interval: 0.96-1.55] for children 3-8 years of age in belt-positioning booster seats). The risk of clinically significant injuries was not associated with weight across a broad weight range in this sample of children in MVCs who were using child restraint systems. Parents should continue to restrain their children according to current recommendations from the American Academy of Pediatrics and the National Highway Traffic Safety Administration.
Overview of the NASA Systems Approach to Crashworthiness Program
NASA Technical Reports Server (NTRS)
Jones, Lisa E.
2002-01-01
The NASA Aviation Safety Program was developed in response to the federal government's goal to reduce the fatal accident rate for aviation by 80% within 10 years. Accident Mitigation is a primary element of the Aviation Safety Program. The overall Accident Mitigation goal is to provide technology to the air transport industry to enable a decrease in the rate of fatalities and injury from crash loads and from in-flight and post-crash explosion and/or fire. Accident Mitigation is divided into two main elements - Fire Prevention and Systems Approach to Crashworthiness. The Systems Approach to Crashworthiness goal is to develop and promote technology that will increase the human survival rate or reduce the fatality rate in survivable accidents. The technical background and planning, selected technical activities, and summary of future efforts will be presented in this paper.
Topology optimization for nonlinear dynamic problems: Considerations for automotive crashworthiness
NASA Astrophysics Data System (ADS)
Kaushik, Anshul; Ramani, Anand
2014-04-01
Crashworthiness of automotive structures is most often engineered after an optimal topology has been arrived at using other design considerations. This study is an attempt to incorporate crashworthiness requirements upfront in the topology synthesis process using a mathematically consistent framework. It proposes the use of equivalent linear systems from the nonlinear dynamic simulation in conjunction with a discrete-material topology optimizer. Velocity and acceleration constraints are consistently incorporated in the optimization set-up. Issues specific to crash problems due to the explicit solution methodology employed, nature of the boundary conditions imposed on the structure, etc. are discussed and possible resolutions are proposed. A demonstration of the methodology on two-dimensional problems that address some of the structural requirements and the types of loading typical of frontal and side impact is provided in order to show that this methodology has the potential for topology synthesis incorporating crashworthiness requirements.
NASA Astrophysics Data System (ADS)
Hamza, Karim; Shalaby, Mohamed
2014-09-01
This article presents a framework for simulation-based design optimization of computationally expensive problems, where economizing the generation of sample designs is highly desirable. One popular approach for such problems is efficient global optimization (EGO), where an initial set of design samples is used to construct a kriging model, which is then used to generate new 'infill' sample designs at regions of the search space where there is high expectancy of improvement. This article attempts to address one of the limitations of EGO, where generation of infill samples can become a difficult optimization problem in its own right, as well as allow the generation of multiple samples at a time in order to take advantage of parallel computing in the evaluation of the new samples. The proposed approach is tested on analytical functions, and then applied to the vehicle crashworthiness design of a full Geo Metro model undergoing frontal crash conditions.
Locomotive crashworthiness research : volume 5 : cab car crashworthiness report
DOT National Transportation Integrated Search
1996-03-01
Models used to analyze locomotive crashworthiness are modified for application to control cab cars of the types used for intercity and commuter rail passenger service. An existing control cab car is analyzed for crashworthiness based on scenarios dev...
49 CFR Appendix E to Part 229 - Performance Criteria for Locomotive Crashworthiness
Code of Federal Regulations, 2011 CFR
2011-10-01
... Crashworthiness E Appendix E to Part 229 Transportation Other Regulations Relating to Transportation (Continued..., App. E Appendix E to Part 229—Performance Criteria for Locomotive Crashworthiness This appendix provides performance criteria for the crashworthiness evaluation of alternative locomotive designs, and...
49 CFR Appendix E to Part 229 - Performance Criteria for Locomotive Crashworthiness
Code of Federal Regulations, 2013 CFR
2013-10-01
... Crashworthiness E Appendix E to Part 229 Transportation Other Regulations Relating to Transportation (Continued..., App. E Appendix E to Part 229—Performance Criteria for Locomotive Crashworthiness This appendix provides performance criteria for the crashworthiness evaluation of alternative locomotive designs, and...
49 CFR Appendix E to Part 229 - Performance Criteria for Locomotive Crashworthiness
Code of Federal Regulations, 2012 CFR
2012-10-01
... Crashworthiness E Appendix E to Part 229 Transportation Other Regulations Relating to Transportation (Continued..., App. E Appendix E to Part 229—Performance Criteria for Locomotive Crashworthiness This appendix provides performance criteria for the crashworthiness evaluation of alternative locomotive designs, and...
49 CFR Appendix E to Part 229 - Performance Criteria for Locomotive Crashworthiness
Code of Federal Regulations, 2014 CFR
2014-10-01
... Crashworthiness E Appendix E to Part 229 Transportation Other Regulations Relating to Transportation (Continued..., App. E Appendix E to Part 229—Performance Criteria for Locomotive Crashworthiness This appendix provides performance criteria for the crashworthiness evaluation of alternative locomotive designs, and...
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false New locomotive crashworthiness design standards and changes to existing FRA-approved locomotive crashworthiness design standards. 229.207 Section 229... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false New locomotive crashworthiness design standards and changes to existing FRA-approved locomotive crashworthiness design standards. 229.207 Section 229... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false New locomotive crashworthiness design standards and changes to existing FRA-approved locomotive crashworthiness design standards. 229.207 Section 229... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false New locomotive crashworthiness design standards and changes to existing FRA-approved locomotive crashworthiness design standards. 229.207 Section 229... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
Differential Risk of Injury to Child Occupants by SUV Size
Kallan, Michael J.; Durbin, Dennis R.; Elliott, Michael R.; Arbogast, Kristy B.; Winston, Flaura K.
2004-01-01
In the United States, the sport utility vehicle (SUV) is the fastest growing segment of the passenger vehicle fleet, yet SUVs vary widely in size and crashworthiness. Using data collected from a population-based sample of crashes in insured vehicles, we quantified the risk of injury to child occupants in SUVs by vehicle weight. There is an increased risk in both Small and Midsize SUVs when compared to Large SUVs. Parents who are purchasing a SUV should strongly consider the size of the vehicle and its crashworthiness. PMID:15319119
Evaluation of wheelchair seating system crashworthiness: "drop hook"-type seat attachment hardware.
Bertocci, G; Ha, D; Deemer, E; Karg, P
2001-04-01
To evaluate the crashworthiness of commercially available hardware that attaches seat surfaces to the wheelchair frame. A low cost static crashworthiness test procedure that simulates a frontal impact motor vehicle crash. Safety testing laboratory. Eleven unique sets of drop-hook hardware made of carbon steel (4), stainless steel (4), and aluminum (3). Replicated seat-loading conditions associated with a 20g/48 kph frontal impact. Test criterion for seat loading was 16,680 N (3750 lb). Failure load and deflection of seat surface. None of the hardware sets tested met the crashworthiness test criterion. All failed at less than 50% of the load that seating hardware could be exposed to in a 20g/48 kph frontal impact. The primary failure mode was excessive deformation, leading to an unstable seat support surface. Results suggest that commercially available seating drop hooks may be unable to withstand loading associated with a frontal crash and may not be the best option for use with transport wheelchairs.
Overview of the NASA Subsonic Rotary Wing Aeronautics Research Program in Rotorcraft Crashworthiness
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Kellas, Sotiris; Fuchs, Yvonne T.
2009-01-01
This paper provides an overview of rotorcraft crashworthiness research being conducted at NASA Langley Research Center under sponsorship of the Subsonic Rotary Wing (SRW) Aeronautics Program. The research is focused in two areas: development of an externally deployable energy attenuating concept and improved prediction of rotorcraft crashworthiness. The deployable energy absorber (DEA) is a composite honeycomb structure, with a unique flexible hinge design that allows the honeycomb to be packaged and remain flat until needed for deployment. The capabilities of the DEA have been demonstrated through component crush tests and vertical drop tests of a retrofitted fuselage section onto different surfaces or terrain. The research on improved prediction of rotorcraft crashworthiness is focused in several areas including simulating occupant responses and injury risk assessment, predicting multi-terrain impact, and utilizing probabilistic analysis methods. A final task is to perform a system-integrated simulation of a full-scale helicopter crash test onto a rigid surface. A brief description of each research task is provided along with a summary of recent accomplishments.
Overview of the NASA Subsonic Rotary Wing Aeronautics Research Program in Rotorcraft Crashworthiness
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Fuchs, Yvonne T.; Kellas, Sotiris
2008-01-01
This paper provides an overview of rotorcraft crashworthiness research being conducted at NASA Langley Research Center under sponsorship of the Subsonic Rotary Wing (SRW) Aeronautics Program. The research is focused in two areas: development of an externally deployable energy attenuating concept and improved prediction of rotorcraft crashworthiness. The deployable energy absorber (DEA) is a composite honeycomb structure, with a unique flexible hinge design that allows the honeycomb to be packaged and remain flat until needed for deployment. The capabilities of the DEA have been demonstrated through component crush tests and vertical drop tests of a retrofitted fuselage section onto different surfaces or terrain. The research on improved prediction of rotorcraft crashworthiness is focused in several areas including simulating occupant responses and injury risk assessment, predicting multi-terrain impact, and utilizing probabilistic analysis methods. A final task is to perform a system-integrated simulation of a full-scale helicopter crash test onto a rigid surface. A brief description of each research task is provided along with a summary of recent accomplishments.
Changes in the Severity and Injury Sources of Thoracic Aorta Injuries due to Vehicular Crashes.
Ryb, Gabriel; Dischinger, Patricia; Kerns, Timothy; Burch, Cynthia; Rabin, Joseph; Ho, Shiu
Research using the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) suggested a decreased adjusted risk of thoracic aorta injuries (TAI) for newer vehicles during near-side crashes and an increased adjusted TAI risk during frontal crashes. This study attempted to explore possible explanations of these findings. Adult front seat occupants in the Crash Injury Research and Engineering Network (CIREN) database through June 2012 were studied. TAI cases were compared with remaining cases in relation to crash and vehicular characteristics. TAI cases of later crash year (CY) (2004-2012) were compared to those in earlier CY (1996-2003) in relation to TAI severity (minor, moderate, severe and non-survivable). TAI cases in newer model year (MY) vehicles (1999-2012) were compared to those in older vehicles (1988-98) in relation to injury source (steering wheel, front, left, seat belt, air bag and other or unknown). Analysis was stratified by direction of impact (frontal and near-side) and the use of restraints. The similar TAI severity of earlier and later CY among frontal crashes suggests that the observed changes in the adjusted odds of injury seen in NASS-CDS are not due to an increase in injury detection. The decrease in TAI severity among newer vehicles in near-side crashes of later CY is consistent with a beneficial effect of crashworthiness improvements for this crash configuration. A shift of injury source in frontal crashes from the steering wheel in older vehicles to "front of vehicle structures", "seat belts" and "unknown and other" in newer vehicles should suggest potential sites for crashworthiness improvements.
Numerical simulation of vehicle crashworthiness and occupant protection
NASA Astrophysics Data System (ADS)
Saha, Nripen K.
1993-08-01
Numerical simulation of vehicle crashworthiness and occupant protection are addressed. The vehicle crashworthiness design objectives are to design the vehicle structure for optimum impact energy absorption, and to design the restraint system (seatbelts, airbags, bolsters, etc.) for optimum occupant protection. The following approaches are taken; a major part of the impact energy is to be absorbed by the vehicle structure; the restraint components will provide protection against the remaining crash energy; certain vehicle components are designed to deform under specific types and speeds of impact in a desired mode for sound energy management; structural components such as front side rails, rear rails, door structure and pillars undergo large amounts of deformation; and with properly designed geometry and material these components assist in mitigating the effects of impact.
Numerical simulation of vehicle crashworthiness and occupant protection
NASA Technical Reports Server (NTRS)
Saha, Nripen K.
1993-01-01
Numerical simulation of vehicle crashworthiness and occupant protection are addressed. The vehicle crashworthiness design objectives are to design the vehicle structure for optimum impact energy absorption, and to design the restraint system (seatbelts, airbags, bolsters, etc.) for optimum occupant protection. The following approaches are taken; a major part of the impact energy is to be absorbed by the vehicle structure; the restraint components will provide protection against the remaining crash energy; certain vehicle components are designed to deform under specific types and speeds of impact in a desired mode for sound energy management; structural components such as front side rails, rear rails, door structure and pillars undergo large amounts of deformation; and with properly designed geometry and material these components assist in mitigating the effects of impact.
Differential risk of injury in child occupants by passenger car classification.
Kallan, Michael J; Durbin, Dennis R; Elliott, Michael R; Menon, Rajiv A; Winston, Flaura K
2003-01-01
In the United States, passenger cars are the most common passenger vehicle, yet they vary widely in size and crashworthiness. Using data collected from a population-based sample of crashes in State Farm-insured vehicles, we quantified the risk of injury to child occupants by passenger car size and classification. Injury risk is predicted by vehicle weight; however, there is an increased risk in both Large vs. Luxury and Sports vs. Small cars, despite similar average vehicle weights in both comparisons. Parents who are purchasing passenger cars should strongly consider the size of the vehicle and its crashworthiness.
Differential Risk of Injury in Child Occupants by Passenger Car Classification
Kallan, Michael J.; Durbin, Dennis R.; Elliott, Michael R.; Menon, Rajiv A.; Winston, Flaura K.
2003-01-01
In the United States, passenger cars are the most common passenger vehicle, yet they vary widely in size and crashworthiness. Using data collected from a population-based sample of crashes in State Farm-insured vehicles, we quantified the risk of injury to child occupants by passenger car size and classification. Injury risk is predicted by vehicle weight; however, there is an increased risk in both Large vs. Luxury and Sports vs. Small cars, despite similar average vehicle weights in both comparisons. Parents who are purchasing passenger cars should strongly consider the size of the vehicle and its crashworthiness. PMID:12941234
Crashworthiness analysis of the Placentia, CA rail collision
DOT National Transportation Integrated Search
2004-07-14
The Volpe Center is supporting the Federal Railroad Administration in performing rail passenger equipment : crashworthiness research. The overall objective of this research is to develop strategies for improving structural crashworthiness : and occup...
Alternative analyses of locomotive structural designs for crashworthiness
DOT National Transportation Integrated Search
2000-01-01
Enhanced crashworthiness performance of North American locomotives is proposed by both increasing the design loads on specific structural components or by describing the crashworthiness performance under specific impact conditions. The design loads f...
Locomotive crashworthiness design modifications study
DOT National Transportation Integrated Search
1999-04-01
A study has been conducted of locomotive crashworthiness in a range of collision scenarios to support the efforts of the Locomotive Crashworthiness Working Group of the Federal Railroad Administration's Railroad Safety Advisory Committee (RSAC) to de...
49 CFR 229.201 - Purpose and scope.
Code of Federal Regulations, 2010 CFR
2010-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...-rail grade crossing. (b) This subpart prescribes minimum crashworthiness standards for locomotives. It also establishes the requirements for obtaining FRA approval of: new locomotive crashworthiness design...
49 CFR 229.201 - Purpose and scope.
Code of Federal Regulations, 2011 CFR
2011-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...-rail grade crossing. (b) This subpart prescribes minimum crashworthiness standards for locomotives. It also establishes the requirements for obtaining FRA approval of: new locomotive crashworthiness design...
49 CFR 229.201 - Purpose and scope.
Code of Federal Regulations, 2013 CFR
2013-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...-rail grade crossing. (b) This subpart prescribes minimum crashworthiness standards for locomotives. It also establishes the requirements for obtaining FRA approval of: new locomotive crashworthiness design...
49 CFR 229.201 - Purpose and scope.
Code of Federal Regulations, 2012 CFR
2012-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...-rail grade crossing. (b) This subpart prescribes minimum crashworthiness standards for locomotives. It also establishes the requirements for obtaining FRA approval of: new locomotive crashworthiness design...
49 CFR 229.201 - Purpose and scope.
Code of Federal Regulations, 2014 CFR
2014-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...-rail grade crossing. (b) This subpart prescribes minimum crashworthiness standards for locomotives. It also establishes the requirements for obtaining FRA approval of: new locomotive crashworthiness design...
Evaluation of cab car crashworthiness design modifications
DOT National Transportation Integrated Search
1997-03-01
A study was conducted to evaluate the effectiveness of structural : modifications to rail cab cars for increased crashworthiness protection in train collisions. The crashworthiness benefits were calculated based on a particular design's ability to pr...
Proposed test method for and evaluation of wheelchair seating system (WCSS) crashworthiness.
van Roosmalen, L; Bertocci, G; Ha, D R; Karg, P; Szobota, S
2000-01-01
Safety of motor vehicle seats is of great importance in providing crash protection to the occupant. An increasing number of wheelchair users use their wheelchairs as motor vehicle seats when traveling. A voluntary standard requires that compliant wheelchairs be dynamically sled impact tested. However, testing to evaluate the crashworthiness of add-on wheelchair seating systems (WCSS) independent of their wheelchair frame is not addressed by this standard. To address this need, this study developed a method to evaluate the crash-worthiness of WCSS with independent frames. Federal Motor Vehicle Safety Standards (FMVSS) 207 test protocols, used to test the strength of motor vehicle seats, were modified and used to test the strength of three WCSS. Forward and rearward loads were applied at the WCSS center of gravity (CGSS), and a moment was applied at the uppermost point of the seat back. Each of the three tested WCSS met the strength requirements of FMVSS 207. Wheelchair seat-back stiffness was also investigated and compared to motor vehicle seat-back stiffness.
49 CFR 229.205 - General requirements.
Code of Federal Regulations, 2014 CFR
2014-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design... the minimum crashworthiness performance requirements set forth in Appendix E of this part. Compliance with those performance criteria must be established by: (1) Meeting an FRA-approved crashworthiness...
49 CFR 229.205 - General requirements.
Code of Federal Regulations, 2011 CFR
2011-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design... the minimum crashworthiness performance requirements set forth in Appendix E of this part. Compliance with those performance criteria must be established by: (1) Meeting an FRA-approved crashworthiness...
49 CFR 229.205 - General requirements.
Code of Federal Regulations, 2012 CFR
2012-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design... the minimum crashworthiness performance requirements set forth in Appendix E of this part. Compliance with those performance criteria must be established by: (1) Meeting an FRA-approved crashworthiness...
49 CFR 229.205 - General requirements.
Code of Federal Regulations, 2010 CFR
2010-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design... the minimum crashworthiness performance requirements set forth in Appendix E of this part. Compliance with those performance criteria must be established by: (1) Meeting an FRA-approved crashworthiness...
49 CFR 229.205 - General requirements.
Code of Federal Regulations, 2013 CFR
2013-10-01
..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design... the minimum crashworthiness performance requirements set forth in Appendix E of this part. Compliance with those performance criteria must be established by: (1) Meeting an FRA-approved crashworthiness...
Changes in the Severity and Injury Sources of Thoracic Aorta Injuries due to Vehicular Crashes
Ryb, Gabriel; Dischinger, Patricia; Kerns, Timothy; Burch, Cynthia; Rabin, Joseph; Ho, Shiu
2013-01-01
Research using the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) suggested a decreased adjusted risk of thoracic aorta injuries (TAI) for newer vehicles during near-side crashes and an increased adjusted TAI risk during frontal crashes. This study attempted to explore possible explanations of these findings. Adult front seat occupants in the Crash Injury Research and Engineering Network (CIREN) database through June 2012 were studied. TAI cases were compared with remaining cases in relation to crash and vehicular characteristics. TAI cases of later crash year (CY) (2004–2012) were compared to those in earlier CY (1996–2003) in relation to TAI severity (minor, moderate, severe and non-survivable). TAI cases in newer model year (MY) vehicles (1999–2012) were compared to those in older vehicles (1988–98) in relation to injury source (steering wheel, front, left, seat belt, air bag and other or unknown). Analysis was stratified by direction of impact (frontal and near-side) and the use of restraints. The similar TAI severity of earlier and later CY among frontal crashes suggests that the observed changes in the adjusted odds of injury seen in NASS-CDS are not due to an increase in injury detection. The decrease in TAI severity among newer vehicles in near-side crashes of later CY is consistent with a beneficial effect of crashworthiness improvements for this crash configuration. A shift of injury source in frontal crashes from the steering wheel in older vehicles to “front of vehicle structures”, “seat belts” and “unknown and other” in newer vehicles should suggest potential sites for crashworthiness improvements. PMID:24406956
Aircraft crashworthiness studies : findings in accidents involving an aerial application aircraft.
DOT National Transportation Integrated Search
1980-04-01
Aircraft crashworthiness features are presented, as others have done, in terms of packaging principles. Modern aerial application aircraft are recognized as being the most crashworthy in the civil aviation fleet. Eighteen accidents involving an aeria...
Crashworthiness Analysis of the UMTA State-of-the-Art Cars
DOT National Transportation Integrated Search
1975-10-01
An engineering assessment of the crashworthiness of the UMTA State-of-the-Art Car (SOAC) has been conducted as part of a program to provide safer transportation to urban rail vehicles. Crash dynamics and crashworthiness methodology based on post-yiel...
49 CFR 229.215 - Retention and inspection of designs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness... crashworthiness features required by this subpart. These records must be retained for the lesser period of: (1... this subpart shall retain all records of repair or modification to crashworthiness features required by...
49 CFR 229.215 - Retention and inspection of designs.
Code of Federal Regulations, 2013 CFR
2013-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness... crashworthiness features required by this subpart. These records must be retained for the lesser period of: (1... this subpart shall retain all records of repair or modification to crashworthiness features required by...
49 CFR 229.215 - Retention and inspection of designs.
Code of Federal Regulations, 2012 CFR
2012-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness... crashworthiness features required by this subpart. These records must be retained for the lesser period of: (1... this subpart shall retain all records of repair or modification to crashworthiness features required by...
49 CFR 229.215 - Retention and inspection of designs.
Code of Federal Regulations, 2010 CFR
2010-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness... crashworthiness features required by this subpart. These records must be retained for the lesser period of: (1... this subpart shall retain all records of repair or modification to crashworthiness features required by...
49 CFR 229.215 - Retention and inspection of designs.
Code of Federal Regulations, 2014 CFR
2014-10-01
... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness... crashworthiness features required by this subpart. These records must be retained for the lesser period of: (1... this subpart shall retain all records of repair or modification to crashworthiness features required by...
Development of airframe design technology for crashworthiness.
NASA Technical Reports Server (NTRS)
Kruszewski, E. T.; Thomson, R. G.
1973-01-01
This paper describes the NASA portion of a joint FAA-NASA General Aviation Crashworthiness Program leading to the development of improved crashworthiness design technology. The objectives of the program are to develop analytical technology for predicting crashworthiness of structures, provide design improvements, and perform full-scale crash tests. The analytical techniques which are being developed both in-house and under contract are described, and typical results from these analytical programs are shown. In addition, the full-scale testing facility and test program are discussed.
49 CFR Appendix E to Part 229 - Performance Criteria for Locomotive Crashworthiness
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Performance Criteria for Locomotive Crashworthiness E Appendix E to Part 229 Transportation Other Regulations Relating to Transportation (Continued..., App. E Appendix E to Part 229—Performance Criteria for Locomotive Crashworthiness This appendix...
DOT National Transportation Integrated Search
1995-07-01
This is the third volume in a series of four that reports on a study in which computer models were developed and applied to evaluate whether various crashworthiness features, as defined in Public Law 102-365, can provide practical benefit to the occu...
Crashworthiness design modifications for locomotive and cab car anticlimbing systems
DOT National Transportation Integrated Search
2003-02-01
This study addressed the feasibility of incorporating complete anticlimbing systems into both passenger and freight locomotives. Complete systems include pushback couplers, vertically interlocking anticlimber elements, and zones specifically designed...
Zhou, Hongyu; Attard, Thomas L.; Dhiradhamvit, Kittinan; ...
2014-11-07
In this paper, the crashworthiness characteristics of rectangular tubes made from a Carbon-fiber reinforced Hybrid-Polymeric Matrix (CHMC) composite were investigated using quasi-static and impact crush tests. The hybrid matrix formulation of the CHMC was created by combining an epoxy-based thermosetting polymer with a lightly crosslinked polyurea elastomer at various cure-time intervals and volumetric ratios. The load–displacement responses of both CHMC and carbon-fiber reinforced epoxy (CF/epoxy) specimens were obtained under various crushing speeds; and crashworthiness parameters, such as the average crushing force and specific energy absorption (SEA), were calculated using subsequent load–displacement relationships. The CHMC maintained a high level of structuralmore » integrity and post-crush performance, relative to traditional CF/epoxy. The influence of the curing time and volumetric ratios of the polyurea/epoxy dual-hybridized matrix system on the crashworthiness parameters was also investigated. The results reveal that the load carrying capacity and total energy absorption tend to increase with greater polyurea thickness and lower elapsed reaction curing time of the epoxy although this is typically a function of the loading rate. In conclusion, the mechanism by which the CHMC provides increased damage tolerance was also investigated using scanning electron microscopy (SEM).« less
Crashworthiness Assessment of Auto-body Members Considering the Fabrication Histories
DOE Office of Scientific and Technical Information (OSTI.GOV)
Huh, Hoon; Song, Jung-Han; Kim, Kee-Poong
2005-08-05
This paper is concerned with crashworthiness of auto-body members considering the effect of fabrication. Most auto-body members are fabricated with sheet metal forming process and welding process that induce fabrication histories such as the plastic work hardening, non-uniform thickness distribution and residual stress. Crash simulation is carried out for auto-body members with LS-DYNA3D in order to identify the fabrication effect on the crashworthiness. The analysis calculated crash mode, the reaction force and the energy absorption for crashworthiness assessment with the forming effect. The result shows that the crash analysis with considering the forming history leads to a different result frommore » that without considering the forming effect. The analysis results demonstrate that the design of auto-body members should be carried out considering the forming history for accurate assessment of the crashworthiness.« less
Structural impact and crashworthiness. Volume 1
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davies, G.A.O.
1984-01-01
This volume contains the keynote addresses of those speakers invited to the International Confernece on Structural Impact and Crashworthiness held at Imperial College, London, in 1984. The speakers represent authoritative views on topics covering the spectrum of impact and crashworthiness involving several materials. The theme of this book may be summarized as 'understanding/modelling/prediction.' Ultimately a crashworthy design depends on many conceptual decisions being correct in the initial design phase. The overall configuration of a structure may be paramount; the detail design of joints and so on has to enable the structure to exploit energy absorption; the fail-safe features must notmore » be prohibitively expensive.« less
Application of DYNA3D in large scale crashworthiness calculations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Benson, D.J.; Hallquist, J.O.; Igarashi, M.
1986-01-01
This paper presents an example of an automobile crashworthiness calculation. Based on our experiences with the example calculation, we make recommendations to those interested in performing crashworthiness calculations. The example presented in this paper was supplied by Suzuki Motor Co., Ltd., and provided a significant shakedown for the new large deformation shell capability of the DYNA3D code. 15 refs., 3 figs.
Absorbable energy monitoring scheme: new design protocol to test vehicle structural crashworthiness.
Ofochebe, Sunday M; Enibe, Samuel O; Ozoegwu, Chigbogu G
2016-05-01
In vehicle crashworthiness design optimization detailed system evaluation capable of producing reliable results are basically achieved through high-order numerical computational (HNC) models such as the dynamic finite element model, mesh-free model etc. However the application of these models especially during optimization studies is basically challenged by their inherent high demand on computational resources, conditional stability of the solution process, and lack of knowledge of viable parameter range for detailed optimization studies. The absorbable energy monitoring scheme (AEMS) presented in this paper suggests a new design protocol that attempts to overcome such problems in evaluation of vehicle structure for crashworthiness. The implementation of the AEMS involves studying crash performance of vehicle components at various absorbable energy ratios based on a 2DOF lumped-mass-spring (LMS) vehicle impact model. This allows for prompt prediction of useful parameter values in a given design problem. The application of the classical one-dimensional LMS model in vehicle crash analysis is further improved in the present work by developing a critical load matching criterion which allows for quantitative interpretation of the results of the abstract model in a typical vehicle crash design. The adequacy of the proposed AEMS for preliminary vehicle crashworthiness design is demonstrated in this paper, however its extension to full-scale design-optimization problem involving full vehicle model that shows greater structural detail requires more theoretical development.
Fire deaths in aircraft without the crashworthy fuel system.
Springate, C S; McMeekin, R R; Ruehle, C J
1989-10-01
Cases reported to the Armed Forces Institute of Pathology were examined for occupants of helicopters without the crashworthy fuel system (CWFS) who survived crashes but died as a result of postcrash fires. There were 16 fire deaths in the 9 such accidents which occurred between January 1976 and April 1984. All of these victims would have survived if there had been no postcrash fire. Partial body destruction by fire probably prevented inclusion of many other cases. The dramatic reduction in fire deaths and injuries due to installation of the CWFS in Army helicopters is discussed. The author concludes that fire deaths and injuries in aircraft accidents could almost be eliminated by fitting current and future aircraft with the CWFS.
Code of Federal Regulations, 2011 CFR
2011-10-01
... crashworthiness, and to realize any savings in collision insurance resulting from differences in damageability, and any savings in medical payment insurance resulting from differences in crashworthiness. ...
Code of Federal Regulations, 2014 CFR
2014-10-01
... crashworthiness, and to realize any savings in collision insurance resulting from differences in damageability, and any savings in medical payment insurance resulting from differences in crashworthiness. ...
Code of Federal Regulations, 2010 CFR
2010-10-01
... crashworthiness, and to realize any savings in collision insurance resulting from differences in damageability, and any savings in medical payment insurance resulting from differences in crashworthiness. ...
Code of Federal Regulations, 2013 CFR
2013-10-01
... crashworthiness, and to realize any savings in collision insurance resulting from differences in damageability, and any savings in medical payment insurance resulting from differences in crashworthiness. ...
Code of Federal Regulations, 2012 CFR
2012-10-01
... crashworthiness, and to realize any savings in collision insurance resulting from differences in damageability, and any savings in medical payment insurance resulting from differences in crashworthiness. ...
NASA Astrophysics Data System (ADS)
Bae, Gihyun; Huh, Hoon; Park, Sungho
This paper deals with a regression model for light weight and crashworthiness enhancement design of automotive parts in frontal car crash. The ULSAB-AVC model is employed for the crash analysis and effective parts are selected based on the amount of energy absorption during the crash behavior. Finite element analyses are carried out for designated design cases in order to investigate the crashworthiness and weight according to the material and thickness of main energy absorption parts. Based on simulations results, a regression analysis is performed to construct a regression model utilized for light weight and crashworthiness enhancement design of automotive parts. An example for weight reduction of main energy absorption parts demonstrates the validity of a regression model constructed.
DOT National Transportation Integrated Search
1978-07-01
The Department of Transportation, Transportation Systems Center (TSC), is providing technical assistance to the Federal Railroad Administration (FRA) in a program to improve railroad safety and efficiency by providing a technological basis for improv...
Crashworthiness evaluation of light rail vehicle interiors.
DOT National Transportation Integrated Search
2011-12-01
Statistically, light rail transit (LRT) systems have higher injury rates on a perpassengermile basis than heavy rail and commuter rail systems, because in most cities, light rail vehicles (LRVs) operate on city streets. Passenger safety is depe...
Passenger rail equipment research in the U.S.
DOT National Transportation Integrated Search
2002-03-22
In 1989 the Federal Railroad Administration (FRA) initiated a program of research into the safety aspects of high-speed passenger train systems. Collision safety the balancing of collision avoidance measures of the system with the crashworthiness...
Locomotive crashworthiness research
DOT National Transportation Integrated Search
2015-04-01
conducts research on locomotive crashworthiness. The research approach includes four phases: : 1. Accident investigations to assemble sequences of events leading to injury and fatality. : 2. Locomotive performance is analyzed, and potential improveme...
Adaptive methods for nonlinear structural dynamics and crashworthiness analysis
NASA Technical Reports Server (NTRS)
Belytschko, Ted
1993-01-01
The objective is to describe three research thrusts in crashworthiness analysis: adaptivity; mixed time integration, or subcycling, in which different timesteps are used for different parts of the mesh in explicit methods; and methods for contact-impact which are highly vectorizable. The techniques are being developed to improve the accuracy of calculations, ease-of-use of crashworthiness programs, and the speed of calculations. The latter is still of importance because crashworthiness calculations are often made with models of 20,000 to 50,000 elements using explicit time integration and require on the order of 20 to 100 hours on current supercomputers. The methodologies are briefly reviewed and then some example calculations employing these methods are described. The methods are also of value to other nonlinear transient computations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pugliese, S.M.
1977-02-01
In Phase I of the Research Safety Vehicle Program (RSV), preliminary design and performance specifications were developed for a mid-1980's vehicle that integrates crashworthiness and occupant safety features with material resource conservation, economy, and producibility. Phase II of the program focused on development of the total vehicle design via systems engineering and integration analyses. As part of this effort, it was necessary to continuously review the Phase I recommended performance specification in relation to ongoing design/test activities. This document contains the results of analyses of the Phase I specifications. The RSV is expected to satisfy all of the producibility andmore » safety related specifications, i.e., handling and stability systems, crashworthiness, occupant protection, pedestrian/cyclist protection, etc.« less
Crashworthiness: Planes, trains, and automobiles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Logan, R.W.; Tokarz, F.J.; Whirley, R.G.
A powerful DYNA3D computer code simulates the dynamic effects of stress traveling through structures. It is the most advanced modeling tool available to study crashworthiness problems and to analyze impacts. Now used by some 1000 companies, government research laboratories, and universities in the U.S. and abroad, DYNA3D is also a preeminent example of successful technology transfer. The initial interest in such a code was to simulate the structural response of weapons systems. The need was to model not the explosive or nuclear events themselves but rather the impacts of weapons systems with the ground, tracking the stress waves as theymore » move through the object. This type of computer simulation augmented or, in certain cases, reduced the need for expensive and time-consuming crash testing.« less
NASA Astrophysics Data System (ADS)
Duan, Libin; Xiao, Ning-cong; Li, Guangyao; Cheng, Aiguo; Chen, Tao
2017-07-01
Tailor-rolled blank thin-walled (TRB-TH) structures have become important vehicle components owing to their advantages of light weight and crashworthiness. The purpose of this article is to provide an efficient lightweight design for improving the energy-absorbing capability of TRB-TH structures under dynamic loading. A finite element (FE) model for TRB-TH structures is established and validated by performing a dynamic axial crash test. Different material properties for individual parts with different thicknesses are considered in the FE model. Then, a multi-objective crashworthiness design of the TRB-TH structure is constructed based on the ɛ-support vector regression (ɛ-SVR) technique and non-dominated sorting genetic algorithm-II. The key parameters (C, ɛ and σ) are optimized to further improve the predictive accuracy of ɛ-SVR under limited sample points. Finally, the technique for order preference by similarity to the ideal solution method is used to rank the solutions in Pareto-optimal frontiers and find the best compromise optima. The results demonstrate that the light weight and crashworthiness performance of the optimized TRB-TH structures are superior to their uniform thickness counterparts. The proposed approach provides useful guidance for designing TRB-TH energy absorbers for vehicle bodies.
Train crashworthiness design for occupant survivability
DOT National Transportation Integrated Search
1995-11-01
Studies were conducted evaluating the effectiveness of alternative strategies for providing crashworthiness of the vehicle structures. Conventional practice results in cars of essentially uniform : longitudinal strength. The crash energy management a...
Fuel tank crashworthiness : loading scenarios
DOT National Transportation Integrated Search
2011-03-16
The Federal Railroad Administrations Office of Research and Development is conducting research into fuel tank crashworthiness. The breaching of fuel tanks during passenger : rail collisions and derailments increases the potential of serious injury...
Liquefied natural gas tender crashworthiness research
DOT National Transportation Integrated Search
2015-03-23
Research is being conducted to develop technical : information needed to formulate effective natural gas fuel : tender crashworthiness standards. This research is being : performed for the Federal Railroad Administrations (FRAs) : Office of Res...
DOT National Transportation Integrated Search
1980-06-01
As systems manager for the Urban Mass Transportation Administration (UMTA) Rail System Supporting Technology Program, the Transportation Systems Center (TSC) is conducting research and development efforts directed toward the introduction of improved ...
Effectiveness of alternative rail passenger equipment crashworthiness strategies
DOT National Transportation Integrated Search
2006-04-04
Crashworthiness strategies, which include crash energy : management (CEM), pushback couplers, and push/pull : operation, are evaluated and compared under specific collision : conditions. Comparisons of three strategies are evaluated in : this paper: ...
The development of crashworthy rails for fiber reinforced polymer honeycomb bridge deck system.
DOT National Transportation Integrated Search
2015-07-01
Fiber reinforced polymer (FRP) honeycomb panels offer an efficient and rapid replacement to : concrete decks. The system consists of FRP honeycomb sandwich panels with adequate guardrails. Although : FRP bridge deck panels have already been designed ...
DOT National Transportation Integrated Search
2015-07-01
Fiber reinforced polymer (FRP) honeycomb panels offer an efficient and rapid : replacement to concrete decks. The system consists of FRP honeycomb sandwich panels : with adequate guardrails. Although FRP bridge deck panels have already been designed ...
Analytical Finite Element Simulation Model for Structural Crashworthiness Prediction
DOT National Transportation Integrated Search
1974-02-01
The analytical development and appropriate derivations are presented for a simulation model of vehicle crashworthiness prediction. Incremental equations governing the nonlinear elasto-plastic dynamic response of three-dimensional frame structures are...
Axial Crushing of Thin-Walled Columns with Octagonal Section: Modeling and Design
NASA Astrophysics Data System (ADS)
Liu, Yucheng; Day, Michael L.
This chapter focus on numerical crashworthiness analysis of straight thinwalled columns with octagonal cross sections. Two important issues in this analysis are demonstrated here: computer modeling and crashworthiness design. In the first part, this chapter introduces a method of developing simplified finite element (FE) models for the straight thin-walled octagonal columns, which can be used for the numerical crashworthiness analysis. Next, this chapter performs a crashworthiness design for such thin-walled columns in order to maximize their energy absorption capability. Specific energy absorption (SEA) is set as the design objective, side length of the octagonal cross section and wall thickness are selected as design variables, and maximum crushing force (Pm) occurs during crashes is set as design constraint. Response surface method (RSM) is employed to formulate functions for both SEA and Pm.
Workstation table crashworthiness tests
DOT National Transportation Integrated Search
2013-12-31
This report describes results from the Option C component of a research program aimed at improving crashworthiness of passenger train workstation tables. Research conducted in the Base, Option A, and Option B components of the program was focused on ...
Rail Safety/Equipment Crashworthiness : Volume 2. Design Guide.
DOT National Transportation Integrated Search
1978-07-01
The second of four volumes, has been prepared to assist design engineers in understanding the basic problems associated with the development of crashworthy interiors of locomotives, cabooses and passenger railcars. Rail vehicle accident conditions ar...
Modular Approach to Structural Simulation for Vehicle Crashworthiness Prediction
DOT National Transportation Integrated Search
1975-03-01
A modular formulation for simulation of the structural deformation and deceleration of a vehicle for crashworthiness and collision compatibility is presented. This formulation includes three dimensional beam elements, various spring elements, rigid b...
Preliminary reconstruction of the November 30, 2007 Chicago, IL rail collision
DOT National Transportation Integrated Search
2011-03-16
The Volpe Center is supporting the Federal Railroad Administration in performing rail passenger equipment crashworthiness research. The overall objective of this research is to develop strategies for improving structural crashworthiness and occupant ...
Locomotive crashworthiness research : executive summary
DOT National Transportation Integrated Search
1995-07-01
Four reports on a study to evaluate whether various crashworthiness features, as defined in Public Law 102-365, can provide practical benefit to the occupants of freight locomotives are summarized. In particular, the benefit was assessed relative to ...
Improved crashworthiness of rail passenger equipment in the United States
DOT National Transportation Integrated Search
2006-06-30
The Federal Railroad Administration has been conducting research to develop strategies for improved passenger : protection in train accidents. Crash energy management (CEM) has been developed as a strategy for structural : crashworthiness. Interior s...
Dummy and injury criteria for aircraft crashworthiness.
DOT National Transportation Integrated Search
1996-04-01
Since 1988, newly type-certificated aircraft are required to comply with stringent crashworthiness requirements. Central to these more stringent requirements is a dynamic test that assesses the potential for injury for someone exposed to similar cond...
NASA Technical Reports Server (NTRS)
Lindsay, Howard A.; Motoyama, Stephen M.; Smith, Kent F.
1990-01-01
The development of composite-related technology applicable to armored crashworthy helicopter crewseats is discussed. The main objective was to achieve a significant weight reduction relative to the first-generation seats exemplified by the UH-60A and the AH-64A designs. This weight reduction was achieved while maintaining full compliance with the most recent version of the military crashworthy crewseat specification, MIL-S-58095A. The technology developed during this effort is intended to apply to the next generation of Army helicopters, such as LHX.
Rail passenger equipment accidents and the evaluation of crashworthiness strategies
DOT National Transportation Integrated Search
2001-05-01
The U.S. Department of Transportation's Federal Railroad Administration's (FRA) Office of Research and Development has been conducting research into rail equipment crashworthiness. The approach taken in conducting this research has been to review rel...
Rail vehicle crashworthiness symposium
DOT National Transportation Integrated Search
1998-03-01
This document contains the proceedings of the Rail Vehicle Crashworthiness Symposium held at the Volpe Center in Cambridge, Massachusetts on June 24, 25, and 26, 1996. These proceedings have been developed from a transcript of the symposium and the m...
Rail passenger equipment accidents and the evaluation of crashworthiness strategies
DOT National Transportation Integrated Search
2002-08-31
The U.S. Department of Transportation's Federal Railroad Administration's (FRA) Office of Research and Development has been conducting research into rail equipment crashworthiness. The approach taken in conducting this research has been to review rel...
77 FR 30047 - Petition for Alternative Locomotive Crashworthiness Design
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-21
... DEPARTMENT OF TRANSPORTATION Federal Railroad Administration [Docket Number FRA-2012-0036..., the National Railroad Passenger Corporation (Amtrak) has petitioned the Federal Railroad Administration (FRA) for approval of alternative locomotive crashworthiness design for an electric locomotive...
Locomotive/Caboose Crashworthiness
DOT National Transportation Integrated Search
1976-01-01
This report presents the results of the Phase I study of the locomotive/caboose crashworthiness program and the proposed work for the Phase II investigation. The results of the Phase I study include the mechanics of train impact that lead to override...
NASA Astrophysics Data System (ADS)
Raman, R.; Jayanth, K.; Sarkar, I.; Ravi, K.
2017-11-01
Crashworthiness of a material is a measure of its ability to absorb energy during a crash. A well-designed crash box is instrumental in protecting the costly vehicle components. A square, hollow, hybrid beam of aluminum/CFRP was subjected to dynamic axial load to analyze the effect of five different lay-up sequences on its crashworthiness. The beam was placed between two plates. Boundary conditions were imposed on them to simulate a frontal body crash test model. Modeling and dynamic analysis of composite structures was done on ABAQUS. Different orientation of carbon fibers varies the crashworthiness of the hybrid beam. Addition of CFRP layer showed clear improvement in specific energy absorption and crush force efficiency compared to pure aluminum beam. Two layers of CFRP oriented at 90° on Aluminum showed 52% increase in CFE.
Locomotive crashworthiness report : volume 4 : additional freight locomotive calculations
DOT National Transportation Integrated Search
1995-07-01
Previously developed computer models (see volume 1) are used to carry out additional calculations for evaluation of road freight locomotive crashworthiness. The effect of fewer locomotives (as would be expected after transition from DC motor to highe...
Locomotive crashworthiness research : volume 1 : model development and validation
DOT National Transportation Integrated Search
1995-07-01
This report is the first of four volumes concerning a study to investigate the costs and benefits of equipping locomotives with various crashworthiness features beyond those currently specified by the Association of American Railroads S-580 specifica...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Benson, D.J.; Hallquist, J.O.; Stillman, D.W.
1985-04-01
Crashworthiness engineering has always been a high priority at Lawrence Livermore National Laboratory because of its role in the safe transport of radioactive material for the nuclear power industry and military. As a result, the authors have developed an integrated, interactive set of finite element programs for crashworthiness analysis. The heart of the system is DYNA3D, an explicit, fully vectorized, large deformation structural dynamics code. DYNA3D has the following four capabilities that are critical for the efficient and accurate analysis of crashes: (1) fully nonlinear solid, shell, and beam elements for representing a structure, (2) a broad range of constitutivemore » models for representing the materials, (3) sophisticated contact algorithms for the impact interactions, and (4) a rigid body capability to represent the bodies away from the impact zones at a greatly reduced cost without sacrificing any accuracy in the momentum calculations. To generate the large and complex data files for DYNA3D, INGRID, a general purpose mesh generator, is used. It runs on everything from IBM PCs to CRAYS, and can generate 1000 nodes/minute on a PC. With its efficient hidden line algorithms and many options for specifying geometry, INGRID also doubles as a geometric modeller. TAURUS, an interactive post processor, is used to display DYNA3D output. In addition to the standard monochrome hidden line display, time history plotting, and contouring, TAURUS generates interactive color displays on 8 color video screens by plotting color bands superimposed on the mesh which indicate the value of the state variables. For higher quality color output, graphic output files may be sent to the DICOMED film recorders. We have found that color is every bit as important as hidden line removal in aiding the analyst in understanding his results. In this paper the basic methodologies of the programs are presented along with several crashworthiness calculations.« less
Development, fabrication, and testing of locomotive crashworthy components
DOT National Transportation Integrated Search
2014-12-02
The Federal Railroad Administration (FRA) and the John A. Volpe National Transportation Systems Center (Volpe Center) are continuing to evaluate new technologies for increasing the safety of passengers and operators in rail equipment. In recognition ...
Schiff, Melissa A; Cummings, Peter
2004-11-01
To evaluate agreement between police and trained investigators regarding seat belt use by crash victims, according to injury severity. We used data from the National Accident Sampling System Crashworthiness Data System (CDS) for front seat occupants, 16 years and older, in crashes during 1993-2000. Crashworthiness Data System investigators determined belt use from vehicle inspection, interviews, and medical record information; their assessment was considered the gold standard for this analysis. Occupant severity of injury was categorized in five levels from no injuries to death. We estimated the sensitivity, specificity, and area under receiver operating characteristic curves for police reports of belt use. Among 48,858 occupants, sensitivity of a police report that a belt was used was 95.8% overall and varied only modestly by injury severity. Specificity of a police report that a belt was not used was 69.1% overall; it was the lowest among the uninjured (53.2%) and greatest among the dead (90.4%). The area under the curve was 0.82 (95% confidence interval 0.82-0.83) overall; this was lowest among those not injured (0.75, 95% confidence interval 0.74-0.76) and increased with injury severity to 0.91 (95% confidence interval 0.90-0.93) among those who died. Police usually classify belted crash victims as belted, regardless of injury severity. But they often classify unbelted survivors as belted when they were not. This misclassification may result in exaggerated estimates of seat belt effectiveness in some studies.
Liquefied natural gas tender crashworthiness in train-to-train collisions
DOT National Transportation Integrated Search
2016-04-12
This paper focuses on technical information to help support : development of alternative static requirements for the train-to-train : collision scenario. The goal of the static requirements is to : provide the same level of crashworthiness as the dyn...
Code of Federal Regulations, 2012 CFR
2012-10-01
... violations is $1,175,000. (d) Consumer information—(1) Crashworthiness and damage susceptibility. A person that violates 49 U.S.C. 32308(a), regarding crashworthiness and damage susceptibility, is liable to the...
Code of Federal Regulations, 2011 CFR
2011-10-01
... violations is $1,175,000. (d) Consumer information—(1) Crashworthiness and damage susceptibility. A person that violates 49 U.S.C. 32308(a), regarding crashworthiness and damage susceptibility, is liable to the...
DOT National Transportation Integrated Search
2015-07-01
Advanced crash avoidance technologies (ACATs) for trucks have been developed in recent years and are beginning : to be deployed. Prior to the development of standards for heavy truck crashworthiness and occupant protection, : additional characterizat...
DOT National Transportation Integrated Search
1975-11-01
The crashworthiness of existing urban rail vehicles (passenger cars) and the feasibility of improvements in this area were investigated. Both rail-car structural configurations and impact absorption devices were studied. This final report issued unde...
A structural survey of classes of vehicles for crashworthiness : final report.
DOT National Transportation Integrated Search
1978-02-01
This document reviews three phases of a study conducted to evaluate and improve the crashworthiness of passenger carrying vehicles in intercity service. Phase I surveyed the accident data over a period 1966 to 1973 and identified those areas responsi...
49 CFR 229.135 - Event recorders.
Code of Federal Regulations, 2010 CFR
2010-10-01
... an event recorder with a certified crashworthy event recorder memory module that meets the... certified crashworthy event recorder memory module that meets the requirements of Appendix D of this part. The certified event recorder memory module shall be mounted for its maximum protection. (Although...
DOT National Transportation Integrated Search
1982-03-01
This report reviews 47 survivable or partly survivable accidents investigated since 1973 by personnel from the Civil Aeromedical Institute. The accidents were reviewed for a number of features of crashworthiness and, in particular, for injuries to oc...
Development, fabrication and testing of locomotive crashworthy components : base effort.
DOT National Transportation Integrated Search
2014-12-01
The Federal Railroad Administration (FRA) and the John A. Volpe National Transportation Systems Center (Volpe Center) are continuing to evaluate new technologies for increasing the safety of passengers and operators in rail equipment. In recognition ...
Finite Element Modeling and Analysis of Thorax/Restraint System Interlock
DOT National Transportation Integrated Search
1994-05-23
Various modeling techniques are playing an increasingly important role as a cost effective means of supplementing crashworthiness data for gaining a better understanding of the injury mechanisms associated with automotive crashes. The interaction of ...
Reduction and mitigation of thermal injuries: what can be done?
Voisine, J J; Albano, J P
1996-01-01
Soon after the introduction of the crashworthy fuel system and Nomex flight apparel, morbidity and mortality rates from thermal injuries in aviation were reduced to zero. Although the incidence of aircraft mishaps involving postcrash fires have remained the same, there has been a recent increase in thermal injury morbidity. These case reports describe three different aircraft accidents in which fire was caused by factors other than the crashworthy fuel system. They also describe sustained thermal injuries and compare them to personal protection equipment. We found that the condition of the personal protective equipment and unauthorized use of unapproved apparel were responsible for the sustained injuries. We maintain that personal protection equipment is effective if worn in the manner for which it was designed. We believe that the lessons learned apply to all military operations where the risk of fire is high, not solely aviation. A proactive program focused on education would reduce the thermal injury morbidity.
Transient analysis techniques in performing impact and crash dynamic studies
NASA Technical Reports Server (NTRS)
Pifko, A. B.; Winter, R.
1989-01-01
Because of the emphasis being placed on crashworthiness as a design requirement, increasing demands are being made by various organizations to analyze a wide range of complex structures that must perform safely when subjected to severe impact loads, such as those generated in a crash event. The ultimate goal of crashworthiness design and analysis is to produce vehicles with the ability to reduce the dynamic forces experienced by the occupants to specified levels, while maintaining a survivable envelope around them during a specified crash event. DYCAST is a nonlinear structural dynamic finite element computer code that started from the plans systems of a finite element program for static nonlinear structural analysis. The essential features of DYCAST are outlined.
Code of Federal Regulations, 2010 CFR
2010-10-01
... that the ERMM meets the performance criteria contained in this appendix and that test verification data are available to a railroad or to FRA upon request. 2. The test verification data shall contain, at a minimum, all pertinent original data logs and documentation that the test sample preparation, test set up...
Code of Federal Regulations, 2011 CFR
2011-10-01
... that the ERMM meets the performance criteria contained in this appendix and that test verification data are available to a railroad or to FRA upon request. 2. The test verification data shall contain, at a minimum, all pertinent original data logs and documentation that the test sample preparation, test set up...
Code of Federal Regulations, 2014 CFR
2014-10-01
... that the ERMM meets the performance criteria contained in this appendix and that test verification data are available to a railroad or to FRA upon request. 2. The test verification data shall contain, at a minimum, all pertinent original data logs and documentation that the test sample preparation, test set up...
Code of Federal Regulations, 2012 CFR
2012-10-01
... that the ERMM meets the performance criteria contained in this appendix and that test verification data are available to a railroad or to FRA upon request. 2. The test verification data shall contain, at a minimum, all pertinent original data logs and documentation that the test sample preparation, test set up...
Code of Federal Regulations, 2013 CFR
2013-10-01
... that the ERMM meets the performance criteria contained in this appendix and that test verification data are available to a railroad or to FRA upon request. 2. The test verification data shall contain, at a minimum, all pertinent original data logs and documentation that the test sample preparation, test set up...
DOT National Transportation Integrated Search
1975-11-01
The crashworthiness of existing urban rail vehicles (passenger cars) and the feasibility of improvements in this area were investigated. Both rail-car structural configurations and impact absorption devices were studied. Recommendations for engineeri...
Locomotive crashworthiness research : volume 2 : design concept generation and evaluation
DOT National Transportation Integrated Search
1995-07-01
This is the second volume in a series of four that reports on a study in which computer models were developed and applied to evaluate whether various crashworthiness features, as defined in Public Law 102-365, can provide practical benefit to the occ...
Passenger vehicle safety in Australasia for different driver groups.
Keall, Michael D; Newstead, Stuart
2011-05-01
Vehicle fleets in developed countries have benefitted from improved technology and regulation leading to safer vehicles. Nevertheless, for various reasons the public do not necessarily choose particular makes and models of cars according to their safety performance. This study aimed to identify areas for potential crashworthiness improvement in the Australasian fleets by studying the distribution of these fleets according to vehicle age and estimated crashworthiness. We used an existing database that encompassed the vast majority of the crash fleets studied, with existing estimates of crashworthiness generated by the Australasian Used Car Safety Ratings project. There were clear tendencies for older and younger people to be driving less safe vehicles that were also generally older. Given that older drivers are more fragile, and hence more liable to be injured in crashes, and younger drivers have a greater propensity to crash, it is clearly undesirable that these driver groups have the least crashworthy vehicles. Some suggestions are made to encourage safer vehicle choices. Copyright © 2010 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Harding, Thomas H.; Rash, Clarence E.; McLean, William E.; Martin, John S.
2015-05-01
Driven by the operational needs of modern warfare, the helmet-mounted display (HMD) has matured from a revolutionary, but impractical, World War I era idea for an infantry marksman's helmet-mounted weapon delivery system to a sophisticated and ubiquitous display and targeting system that dominates current night warfighting operations. One of the most demanding applications for HMD designs has been in Army rotary-wing aviation, where HMDs offer greater direct access to visual information and increased situational awareness in an operational environment where information availability is critical on a second-to-second basis. However, over the past 40 years of extensive HMD development, a myriad of crashworthiness, optical, and human factors issues have both frustrated and challenged designers. While it may be difficult to attain a full consensus on which are the most important HMD design factors, certainly head-supported weight (HSW), exit pupil size, field-of-view, image resolution and physical eye relief have been among the most critical. A confounding factor has been the interrelationship between the many design issues, such as early attempts to use non-glass optical elements to lower HSW, but at the cost of image quality, and hence, pilot visual performance. This paper traces how the role of the demanding performance requirements placed on HMDs by the U.S. Army aviation community has impacted the progress of HMD designs towards the Holy Grail of HMD design: a wide field-of-view, high resolution, binocular, full-color, totally crashworthy system.
Development of a frontal small overlap crashworthiness evaluation test.
Sherwood, Christopher P; Mueller, Becky C; Nolan, Joseph M; Zuby, David S; Lund, Adrian K
2013-01-01
Small overlap frontal crashes are those in which crash forces are applied outboard of the vehicle's longitudinal frame rails. In-depth analyses of crashes indicate that such crashes account for a significant proportion of frontal crashes with seriously injured occupants. The objective of this research was to evaluate possible barrier crash tests that could be used to evaluate the crashworthiness of vehicles across a spectrum of small overlap crash types. Sixteen full-scale vehicle tests were conducted using 3 midsize passenger vehicles in up to 6 different test configurations, including vehicle-to-vehicle and barrier tests. All vehicles were tested at 64 km/h with an instrumented Hybrid III midsize male driver dummy. All test configurations resulted in primary loading of the wheel, suspension system, and hinge pillar. Vehicles underwent substantial lateral movement during the crash, which varied by crash configuration. The occupant compartments had significant intrusion, particularly to the most outboard structures. Inboard movement of the steering wheel in combination with outboard movement of the dummies (due to the lateral vehicle motion) caused limited interaction with the frontal air bag in most cases. When assessing overall crashworthiness (based on injury measures, structural deformation, and occupant kinematics), one vehicle had superior performance in each crash configuration. This was confirmation that the countermeasures benefiting performance in a single small overlap test also will provide a benefit in other crash configurations. Based on these test results, the Insurance Institute for Highway Safety has developed a small overlap crashworthiness evaluation with the following characteristics: a rigid flat barrier with a 150-mm corner radius, 25 percent overlap, 64 km/h test speed, and a Hybrid III midsize male driver dummy.
Safety and Crashworthiness of Dual Mode Vehicles
DOT National Transportation Integrated Search
1974-01-01
Safety features and the degree of safety expected of dual-mode systems are reviewed. Some of the inherent advantages and disadvantages of dual-mode transportation are also outlined. Possible categories of vehicle safety are defined to aid in developi...
Full-scale two-car impact test: comparison of measured and model results
DOT National Transportation Integrated Search
2004-04-06
The Volpe National Transportation Systems Center is : conducting research into the crashworthiness of rail vehicles in : support of the Federal Railroad Administration's Office of : Research and Development. The approach taken has focused on : the re...
Crashworthiness evaluation of mass transit buses.
DOT National Transportation Integrated Search
2008-11-01
Mass transit bus systems are an integral part of the national transportation network, serving more than 20.6 billion passenger-miles per year with a relatively low fatality rate. Bus occupant injuries are evenly distributed among crashes on all sides...
DOT National Transportation Integrated Search
1998-02-01
A general methodology is developed for estimating the change in the number of injuries and fatalities expected as a result of a change in vehicle crashworthiness design. It is assumed that crash tests have provided information on dummy response measu...
Impact analysis of composite aircraft structures
NASA Technical Reports Server (NTRS)
Pifko, Allan B.; Kushner, Alan S.
1993-01-01
The impact analysis of composite aircraft structures is discussed. Topics discussed include: background remarks on aircraft crashworthiness; comments on modeling strategies for crashworthiness simulation; initial study of simulation of progressive failure of an aircraft component constructed of composite material; and research direction in composite characterization for impact analysis.
Vehicle crashworthiness ratings in Australia.
Cameron, M; Mach, T; Neiger, D; Graham, A; Ramsay, R; Pappas, M; Haley, J
1994-08-01
The paper reviews the published vehicle safety ratings based on mass crash data from the United States, Sweden, and Great Britain. It then describes the development of vehicle crashworthiness ratings based on injury compensation claims and police accident reports from Victoria and New South Wales, the two most populous states in Australia. Crashworthiness was measured by a combination of injury severity (of injured drivers) and injury risk (of drivers involved in crashes). Injury severity was based on 22,600 drivers injured in crashes in the two states. Injury risk was based on 70,900 drivers in New South Wales involved in crashes after which a vehicle was towed away. Injury risk measured in this way was compared with the "relative injury risk" of particular model cars involved in two car crashes in Victoria (where essentially only casualty crashes are reported), which was based on the method developed by Folksam Insurance in Sweden from Evans' double-pair comparison method. The results include crashworthiness ratings for the makes and models crashing in Australia in sufficient numbers to measure their crash performance adequately. The ratings were normalised for the driver sex and speed limit at the crash location, the two factors found to be strongly related to injury risk and/or severity and to vary substantially across makes and models of Australian crash-involved cars. This allows differences in crashworthiness of individual models to be seen, uncontaminated by major crash exposure differences.
49 CFR 229.209 - Alternative locomotive crashworthiness designs.
Code of Federal Regulations, 2010 CFR
2010-10-01
... locomotive crashworthiness design, in detail; (3) The intended type of service for locomotives built under the proposed design; and (4) Appropriate data and analysis showing how the design either satisfies the requirements of § 229.205 for the type of locomotive or provides at least an equivalent level of safety. Types...
DOT National Transportation Integrated Search
2011-10-01
Criteria and procedures have been developed for assessing crashworthiness and occupant protection performance of alternatively designed trainsets to be used in Tier I (not exceeding 125 mph) passenger service. These criteria and procedures take advan...
Crashworthiness of Restraints for Physically Disabled Children in Buses.
ERIC Educational Resources Information Center
Seeger, Barry R.; Caudrey, David J.
1983-01-01
Seven design principles identified from research as crashworthy for transporting disabled persons in buses are listed, and survey results of transportation of 161 disabled children in Australia are discussed relative to the design principles. Findings are discussed and recommendations made to correct deviations, such as absence of lapbelts. (MC)
Bahouth, George; Digges, Kennerly; Schulman, Carl
2012-01-01
This paper presents methods to estimate crash injury risk based on crash characteristics captured by some passenger vehicles equipped with Advanced Automatic Crash Notification technology. The resulting injury risk estimates could be used within an algorithm to optimize rescue care. Regression analysis was applied to the National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) to determine how variations in a specific injury risk threshold would influence the accuracy of predicting crashes with serious injuries. The recommended thresholds for classifying crashes with severe injuries are 0.10 for frontal crashes and 0.05 for side crashes. The regression analysis of NASS/CDS indicates that these thresholds will provide sensitivity above 0.67 while maintaining a positive predictive value in the range of 0.20. PMID:23169132
Analysis of existing work-zone devices with MASH safety performance criteria.
DOT National Transportation Integrated Search
2009-02-01
Crashworthy, work-zone, portable sign support systems accepted under NCHRP Report No. 350 were analyzed to : predict their safety peformance according to the TL-3 MASH evaluation criteria. An analysis was conducted to determine : which hardware param...
Vehicle aggressivity : fleet characterization using traffic collision data
DOT National Transportation Integrated Search
1998-02-01
The objective of this study was to determine the crashworthiness and aggressivity of passenger cars, light trucks and vans (LTVs) in traffic collisions. The data for the analysis was taken from the NHTSA Fatal Analysis Reporting System (FARS) and the...
Multi-point objective-oriented sequential sampling strategy for constrained robust design
NASA Astrophysics Data System (ADS)
Zhu, Ping; Zhang, Siliang; Chen, Wei
2015-03-01
Metamodelling techniques are widely used to approximate system responses of expensive simulation models. In association with the use of metamodels, objective-oriented sequential sampling methods have been demonstrated to be effective in balancing the need for searching an optimal solution versus reducing the metamodelling uncertainty. However, existing infilling criteria are developed for deterministic problems and restricted to one sampling point in one iteration. To exploit the use of multiple samples and identify the true robust solution in fewer iterations, a multi-point objective-oriented sequential sampling strategy is proposed for constrained robust design problems. In this article, earlier development of objective-oriented sequential sampling strategy for unconstrained robust design is first extended to constrained problems. Next, a double-loop multi-point sequential sampling strategy is developed. The proposed methods are validated using two mathematical examples followed by a highly nonlinear automotive crashworthiness design example. The results show that the proposed method can mitigate the effect of both metamodelling uncertainty and design uncertainty, and identify the robust design solution more efficiently than the single-point sequential sampling approach.
Crashworthy airframe design concepts: Fabrication and testing
NASA Technical Reports Server (NTRS)
Cronkhite, J. D.; Berry, V. L.
1982-01-01
Crashworthy floor concepts applicable to general aviation aircraft metal airframe structures were investigated. Initially several energy absorbing lower fuselage structure concepts were evaluated. Full scale floor sections representative of a twin engine, general aviation airplane lower fuselage structure were designed and fabricated. The floors featured an upper high strength platform with an energy absorbing, crushable structure underneath. Eighteen floors were fabricated that incorporated five different crushable subfloor concepts. The floors were then evaluated through static and dynamic testing. Computer programs NASTRAN and KRASH were used for the static and dynamic analysis of the floor section designs. Two twin engine airplane fuselages were modified to incorporate the most promising crashworthy floor sections for test evaluation.
Energy absorption capability and crashworthiness of composite material structures: A review
DOE Office of Scientific and Technical Information (OSTI.GOV)
Carruthers, J.J.; Kettle, A.P.; Robinson, A.M.
1998-10-01
The controlled brittle failure of thermosetting fiber-reinforced polymer composites can provide a very efficient energy absorption mechanism. Consequently, the use of these materials in crashworthy vehicle designs has been the subject of considerable interest. In this respect, their more widespread application has been limited by the complexity of their collapse behavior. This article reviews the current level of understanding i this field, including the correlations between failure mode and energy absorption, the principal material, geometric, and physical parameters relevant to crashworthy design and methods of predicting the energy absorption capability of polymer composites. Areas which require further investigation are identified.more » This review article contains 70 references.« less
Commercial jet transport crashworthiness
NASA Technical Reports Server (NTRS)
Widmayer, E.; Brende, O. B.
1982-01-01
The results of a study to identify areas of research and approaches that may result in improved occupant survivability and crashworthiness of transport aircraft are given. The study defines areas of structural crashworthiness for transport aircraft which might form the basis for a research program. A 10-year research and development program to improve the structural impact resistance of general aviation and commercial jet transport aircraft is planned. As part of this program parallel studies were conducted to review the accident experience of commercial transport aircraft, assess the accident performance of structural components and the status of impact resistance technology, and recommend areas of research and development for that 10-year plan. The results of that study are also given.
Crashdynamics with DYNA3D: Capabilities and research directions
NASA Technical Reports Server (NTRS)
Whirley, Robert G.; Engelmann, Bruce E.
1993-01-01
The application of the explicit nonlinear finite element analysis code DYNA3D to crashworthiness problems is discussed. Emphasized in the first part of this work are the most important capabilities of an explicit code for crashworthiness analyses. The areas with significant research promise for the computational simulation of crash events are then addressed.
Aortic injuries in newer vehicles.
Ryb, Gabriel E; Dischinger, Patricia C; Kleinberger, Michael; McGwin, Gerald; Griffin, Russell L
2013-10-01
The occurrence of AI was studied in relation to vehicle model year (MY) among front seat vehicular occupants, age≥16 in vehicles MY≥1994, entered in the National Automotive Sampling System Crashworthiness Data System between 1997 and 2010 to determine whether newer vehicles, due to their crashworthiness improvements, are linked to a lower risk of aortic injuries (AI). MY was categorized as 1994-1997, 1998-2004, or 2005-2010 reflecting the introduction of newer occupant protection technology. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals for the association between AI and MY independent of possible confounders. Analysis was repeated, stratified by frontal and near lateral impacts. AI occurred in 19,187 (0.06%) of the 31,221,007 (weighted) cases, and contributed to 11% of all deaths. AIs were associated with advanced age, male gender, high BMI, near-side impact, rollover, ejection, collision against a fixed object, high ΔV, vehicle mismatch, unrestrained status, and forward track position. Among frontal crashes, MY 98-04 and MY 05-10 showed increased adjusted odds of AI when compared to MY 94-97 [OR 1.84 (1.02-3.32) and 1.99 (0.93-4.26), respectively]. In contrast, among near-side impact crashes, MY 98-04 and MY 05-10 showed decreased adjusted odds of AI [OR 0.50 (0.25-0.99) and 0.27 (0.06-1.31), respectively]. While occupants of newer vehicles experience lower odds of AI in near side impact crashes, a higher AI risk is present in frontal crashes. Copyright © 2013 Elsevier Ltd. All rights reserved.
Prototype design and test of a collision protection system for cab car engineers.
DOT National Transportation Integrated Search
2014-12-01
Advancements in the design of rail cars can : potentially prevent the structural collapse of : space occupied by a cab car engineer : during a train collision. With adequate : survival space maintained, the next : crashworthiness objective is to mini...
Mash evaluation of TxDOT high-mounting-height temporary work zone sign support system.
DOT National Transportation Integrated Search
2017-02-01
The objective of this research was to develop a nonproprietary, lightweight, crashworthy, temporary work-zone single sign support for use with an aluminum sign substrate. The device is intended to meet the evaluation criteria in American Association ...
Emerging Technologies in Aircraft Crashworthiness
1999-05-01
is both lightweight and accommodates the expanding occupant range. Solutions such as EA’s with variable-thickness wire-benders, multiple-stage wire ... bending mechanisms, and energy-absorbing foams have been developed. Another focus will be on restraint-system integration that is designed for a
Prototype design of a collision protection system for cab car engineers - fabrication and test.
DOT National Transportation Integrated Search
2015-06-01
Advancements in the structural crashworthiness of passenger rail cars now make it possible to preserve the compartmentalized : space occupied by a cab car engineer during a train collision. In order to translate this additional protection into improv...
77 FR 8326 - Petition for Waiver of Compliance
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-14
... 2010, FRA formed an Engineering Task Force (ETF) to develop crashworthiness criteria for an... system with other compliant Tier 1 equipments. The waiver petition includes documentation on the... Integrity Colliding Equipment Override Fluid Entry Inhibition End Structure Integrity of Cab End End...
DOT National Transportation Integrated Search
1996-10-01
Tests have been conducted on Amtrak's traditional passenger seat to evaluate its performance under static and dynamic loading conditions. Quasi-static tests have been conducted to establish the load-deflection characteristics of the seat. Dynamic tes...
Projecting effects of improvements in passive safety of the New Zealand light vehicle fleet.
Keall, Michael; Newstead, Stuart; Jones, Wayne
2007-09-01
In the year 2000, as part of the process for setting New Zealand road safety targets, a projection was made for a reduction in social cost of 15.5 percent associated with improvements in crashworthiness, which is a measure of the occupant protection of the light passenger vehicle fleet. Since that document was produced, new estimates of crashworthiness have become available, allowing for a more accurate projection. The objective of this paper is to describe a methodology for projecting changes in casualty rates associated with passive safety features and to apply this methodology to produce a new prediction. The shape of the age distribution of the New Zealand light passenger vehicle fleet was projected to 2010. Projected improvements in crashworthiness and associated reductions in social cost were also modeled based on historical trends. These projections of changes in the vehicle fleet age distribution and of improvements in crashworthiness together provided a basis for estimating the future performance of the fleet in terms of secondary safety. A large social cost reduction of about 22 percent for 2010 compared to the year 2000 was predicted due to the expected huge impact of improvements in passive vehicle features on road trauma in New Zealand. Countries experiencing improvements in their vehicle fleets can also expect significant reductions in road injury compared to a less crashworthy passenger fleet. Such road safety gains can be analyzed using some of the methodology described here.
Aircraft Survivability. Summer 2011
2011-01-01
airbag systems and the DEA, offer unique advantages for improving rotorcraft crashworthiness, either as stand-alone systems or in conjunction with a...deployment methods were studied with the goal of achieving equivalent deployment times as external airbag systems. Since 2006, experimental evaluation of...Y., Gansman B., and Bradney C., “Rotorcraft External Airbag Protection System,” Proceedings of the AHS 62nd Annual Forum, Phoenix AZ, May 2006. 5
Design and Test of an Improved Crashworthiness Small Composite Airframe
NASA Technical Reports Server (NTRS)
Terry, James E.; Hooper, Steven J.; Nicholson, Mark
2002-01-01
The purpose of this small business innovative research (SBIR) program was to evaluate the feasibility of developing small composite airplanes with improved crashworthiness. A combination of analysis and half scale component tests were used to develop an energy absorbing airframe. Four full scale crash tests were conducted at the NASA Impact Dynamics Research Facility, two on a hard surface and two onto soft soil, replicating earlier NASA tests of production general aviation airplanes. Several seat designs and restraint systems including both an air bag and load limiting shoulder harnesses were tested. Tests showed that occupant loads were within survivable limits with the improved structural design and the proper combination of seats and restraint systems. There was no loss of cabin volume during the events. The analysis method developed provided design guidance but time did not allow extending the analysis to soft soil impact. This project demonstrated that survivability improvements are possible with modest weight penalties. The design methods can be readily applied by airplane designers using the examples in this report.
Rogers, P D; Gibson, C; Wilcox, S J; Chong, A
2009-01-01
The crashworthiness of occupied proprietary wheelchairs, which are transported in motor vehicles, is currently assessed by physical crash testing in accordance with ISO 7176-19. If such wheelchairs are modified to meet the needs of the occupant, e.g. the addition of special seating, environmental control systems or life support equipment, then those making the modifications take on the manufacturer's responsibilities, one of these being the assessment of the modified wheelchair's ability to withstand vehicle crash forces. Destructively testing bespoke wheelchair designs is not practical so, currently, the transport-related risk is assessed using best engineering judgement. To improve this process virtual crash testing of the wheelchair and occupant was used. A modified crash criteria from ISO 7176-19 is proposed to enable assessment of the wheelchair's crashworthiness and provide the clinical engineer with an informed judgement of how both wheelchair alone and occupant and wheelchair together will behave in a crash.
DYNA3D: A computer code for crashworthiness engineering
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hallquist, J.O.; Benson, D.J.
1986-09-01
A finite element program with crashworthiness applications has been developed at LLNL. DYNA3D, an explicit, fully vectorized, finite deformation structural dynamics program, has four capabilities that are critical for the efficient and realistic modeling crash phenomena: (1) fully optimized nonlinear solid, shell, and beam elements for representing a structure; (2) a broad range of constitutive models for simulating material behavior; (3) sophisticated contact algorithms for impact interactions; (4) a rigid body capability to represent the bodies away from the impact region at a greatly reduced cost without sacrificing accuracy in the momentum calculations. Basic methodologies of the program are brieflymore » presented along with several crashworthiness calculations. Efficiencies of the Hughes-Liu and Belytschko-Tsay shell formulations are considered.« less
Stucki, Sheldon Lee; Biss, David J.
2000-01-01
An analysis was performed using the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) database to compare the injury/fatality rates of variously restrained driver occupants as compared to unrestrained driver occupants in the total database of drivers/frontals, and also by Delta-V. A structured search of the NASS-CDS was done using the SAS® statistical analysis software to extract the data for this analysis and the SUDAAN software package was used to arrive at statistical significance indicators. In addition, this paper goes on to investigate different methods for presenting results of accident database searches including significance results; a risk versus Delta-V format for specific exposures; and, a percent cumulative injury versus Delta-V format to characterize injury trends. These alternative analysis presentation methods are then discussed by example using the present study results. PMID:11558105
NASA Astrophysics Data System (ADS)
Jones, N.; Wierzbicki, T.
The application of solid, structural, and experimental mechanics to predict the crumpling behavior and energy absorption of thin-walled structures under quasi-static compression and various dynamic crash loadings is examined in reviews of current research. Both fundamental aspects and specific problems in the design of crashworthy aircraft, automobiles, railroad cars, ships, and offshore installations are considered. Topics discussed include laterally compressed metal tubes as impact-energy absorbers, crushing behavior of plate intersections, axial crushing of fiber-reinforced composite tubes, finite-element analysis of structural crashworthiness in the automotive and aerospace industries, crash behavior of aircraft fuselage structures, aircraft crash analysis, ship collisions, and structural damage in airship and rolling-stock collisions. Photographs, graphs, drawings, and diagrams are provided.
Crashworthiness Design for Bionic Bumper Structures Inspired by Cattail and Bamboo.
Xu, Tao; Liu, Nian; Yu, Zhenglei; Xu, Tianshuang; Zou, Meng
2017-01-01
Many materials in nature exhibit excellent mechanical properties. In this study, we evaluated the bionic bumper structure models by using nonlinear finite element (FE) simulations for their crashworthiness under full-size impact loading. The structure contained the structural characteristics of cattail and bamboo. The results indicated that the bionic design enhances the specific energy absorption (SEA) of the bumper. The numerical results showed that the bionic cross-beam and bionic box of the bionic bumper have a significant effect on the crashworthiness of the structure. The crush deformation of bionic cross-beam and box bumper model was reduced by 33.33%, and the total weight was reduced by 44.44%. As the energy absorption capacity under lateral impact, the bionic design can be used in the future bumper body.
Lightweight, fire-retardant, crashworthy aircraft seat cushioning
NASA Technical Reports Server (NTRS)
Haslim, Leonard A.; Mcdonough, Paul T.
1991-01-01
A two page discussion of non-aerospace seating applications and the design of NASA's safety seat cushioning (SSC) is presented. The SSC was designed for both safety and comfort in order to replace polyurethane cushioning which is flammable and produces lethal fumes upon combustion. The SSC is composed of advanced fabric reinforced composites and is lightweight, fire-retardent, and crashworthy. The seat design consists of central elliptical tubular spring supports made of fire-resistant and fatigue-durable composites surrounded by a fire-blocking sheath. The cushioning is made crashworthy by incorporating energy-absorbing, viscoelastic layers between the nested, elliptical-hoop springs. The design is intended to provide comfortable seating that meets aircraft-loading requirements without using the conventional polyurethane materials. The designs of an aircraft seat and structural components of the SSC are also presented.
Crashworthiness Design for Bionic Bumper Structures Inspired by Cattail and Bamboo
Xu, Tao; Liu, Nian
2017-01-01
Many materials in nature exhibit excellent mechanical properties. In this study, we evaluated the bionic bumper structure models by using nonlinear finite element (FE) simulations for their crashworthiness under full-size impact loading. The structure contained the structural characteristics of cattail and bamboo. The results indicated that the bionic design enhances the specific energy absorption (SEA) of the bumper. The numerical results showed that the bionic cross-beam and bionic box of the bionic bumper have a significant effect on the crashworthiness of the structure. The crush deformation of bionic cross-beam and box bumper model was reduced by 33.33%, and the total weight was reduced by 44.44%. As the energy absorption capacity under lateral impact, the bionic design can be used in the future bumper body. PMID:29118571
Evolution of the crashworthiness and aggressivity of the Spanish car fleet.
Gómez Méndez, Alvaro; Aparicio Izquierdo, Francisco; Arenas Ramírez, Blanca
2010-11-01
This paper investigates the relationship between a passenger car's year of registration and its crashworthiness and aggressivity in real-world crashes. Crashworthiness is defined as the ability of a car to protect its own occupants, and has been evaluated in single and two-car crashes. Aggressivity is defined as the ability to protect users travelling in other vehicles, and has been evaluated only in two-car crashes. The dependent variable is defined as the proportion of injured drivers who are killed or seriously injured; following previous research, we refer to this magnitude as injury severity. A decrease in the injury severity of a driver is interpreted as an improvement in the crashworthiness of their car; similarly, a decrease in the injury severity of the opponent driver is regarded as an improvement in aggressivity. Data have been extracted from the Spanish Road Accident Database, which contains information on every accident registered by the police in which at least one person was injured. Two types of regression models have been used: logistic regression models in single-car crashes, and generalised estimating equations (GEE) models in two-car crashes. GEE allow to take account of the correlation between the injury severities of drivers involved in the same crash. The independent variables considered have been: year of registration of the subject car (crashworthiness component), year of registration of the opponent car (aggressivity component), and several factors related to road, driver and environment. Our models confirm that crashworthiness has largely improved in two-car crashes: when crashing into the average opponent car, drivers of cars registered before 1985 have a significantly higher probability of being killed or seriously injured than drivers of cars registered in 2000-2005 (odds ratio: 1.80; 95% confidence interval: 1.61; 2.01). In single-car crashes, the improvement in crashworthiness is very slight (odds ratio: 1.04; 95% confidence interval: 0.93; 1.16). On the other hand, we have also found a significant worsening in aggressivity in two-car crashes: the driver of the average car has a significantly lower probability of being killed or seriously injured when crashing into a car registered before 1985, than when crashing into a car registered in 2000-2005 (odds ratio: 0.52; 95% confidence interval: 0.45; 0.60). Our results are consistent with a large amount of previous research that has reported significant improvements in the protection of car occupants. They also add to some recent studies that have found a worsening in the aggressivity of modern cars. This trend may be reflecting the impact of differences in masses and travel speeds, as well as the influence of consumer choices. The precise reasons have to be investigated. Also, the causes have to be found for so large a discrepancy between crashworthiness in single and two-car crashes. 2010 Elsevier Ltd. All rights reserved.
75 FR 17590 - Federal Motor Vehicle Safety Standards; Roof Crush Resistance
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-07
... FURTHER INFORMATION CONTACT: For non-legal issues, you may call Christopher J. Wiacek, NHTSA Office of Crashworthiness Standards, telephone 202-366-4801. For legal issues, you may call J. Edward Glancy, NHTSA Office... assemblage consisting, at a minimum, of chassis (including the frame) structure, power train, steering system...
Fundamental Studies on Crashworthiness Design with Uncertainties in the System
2005-01-01
studied; examples include using the Response Surface Methods (RSM) and Design of Experiment (DOE) [2-4]. Space Mapping (SM) is another practical...Exposed to Impact Load Using a Space Mapping Technique,” Struct. Multidisc. Optim., Vol. 27, pp. 411-420 (2004). 6. Mayer, R. R., Kikuchi, N. and Scott
Fundamental Studies on Crashworthiness Design with Uncertainties in the System
2005-01-01
studied; examples include using the Response Surface Methods (RSM) and Design of Experiment (DOE) [2-4]. Space Mapping (SM) is another practical...to Impact Load Using a Space Mapping Technique," Struct. Multidisc. Optim., Vol. 27, pp. 411-420 (2004). 6. Mayer, R. R., Kikuchi, N. and Scott, R
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.
On computational methods for crashworthiness
NASA Technical Reports Server (NTRS)
Belytschko, T.
1992-01-01
The evolution of computational methods for crashworthiness and related fields is described and linked with the decreasing cost of computational resources and with improvements in computation methodologies. The latter includes more effective time integration procedures and more efficient elements. Some recent developments in methodologies and future trends are also summarized. These include multi-time step integration (or subcycling), further improvements in elements, adaptive meshes, and the exploitation of parallel computers.
Army Helicopter Crashworthiness
1983-10-01
protect the structure surrounding the occupied Cabin volume. Components. An important part of this program was to evaluate analysis methods that could...rigid (nonstroking) seats and the production BLACK HAWK helicopter crashworthy crewseat. Tests of three embalmed cadavers in the rigid seat gave mixed...CONDITIONS FOR RIGID SEAT TESTS WITH EMBALMED CADAVERS 1 CADAVER WEIGHT PEAK TEST NO. NO. AGE HEIGHT (LB) SEX ACCEL. (G) FRACTURE CONDITION SERIES #1
Design of crashworthy structures with controlled behavior in HCA framework
NASA Astrophysics Data System (ADS)
Bandi, Punit
The field of crashworthiness design is gaining more interest and attention from automakers around the world due to increasing competition and tighter safety norms. In the last two decades, topology and topometry optimization methods from structural optimization have been widely explored to improve existing designs or conceive new designs with better crashworthiness. Although many gradient-based and heuristic methods for topology- and topometry-based crashworthiness design are available these days, most of them result in stiff structures that are suitable only for a set of vehicle components in which maximizing the energy absorption or minimizing the intrusion is the main concern. However, there are some other components in a vehicle structure that should have characteristics of both stiffness and flexibility. Moreover, the load paths within the structure and potential buckle modes also play an important role in efficient functioning of such components. For example, the front bumper, side frame rails, steering column, and occupant protection devices like the knee bolster should all exhibit controlled deformation and collapse behavior. The primary objective of this research is to develop new methodologies to design crashworthy structures with controlled behavior. The well established Hybrid Cellular Automaton (HCA) method is used as the basic framework for the new methodologies, and compliant mechanism-type (sub)structures are the highlight of this research. The ability of compliant mechanisms to efficiently transfer force and/or motion from points of application of input loads to desired points within the structure is used to design solid and tubular components that exhibit controlled deformation and collapse behavior under crash loads. In addition, a new methodology for controlling the behavior of a structure under multiple crash load scenarios by adaptively changing the contributions from individual load cases is developed. Applied to practical design problems, the results demonstrate that the methodologies provide a practical tool to aid the design engineer in generating design concepts for crashworthy structures with controlled behavior. Although developed in the HCA framework, the basic ideas behind these methods are generic and can be easily implemented with other available topology- and topometry-based optimization methods.
NASA Technical Reports Server (NTRS)
Warrick, J. C.; Desjardins, S. P.
1979-01-01
This report presents the methodology and results of a program conducted to develop two underseat energy absorber (E/A) concepts for application to nonadjustable crashworthy passenger seats for general aviation aircraft. One concept utilizes an inflated air bag, and the other, a convoluted sheet metal bellows. Prototypes of both were designed, built, and tested. Both concepts demonstrated the necessary features of an energy absorber (load-limiter); however, the air bag concept is particularly encouraging because of its light weight. Several seat frame concepts also were investigated as a means of resisting longitudinal and lateral loads and of guiding the primary vertical stroke of the underseat energy absorber. Further development of a seat system design using the underseat energy absorbers is recommended because they provide greatly enhanced crash survivability as compared with existing general aviation aircraft seats.
Numerical simulation of a novel expanded metal tubular structure for crashworthiness application
NASA Astrophysics Data System (ADS)
Abdelaal, A. H. A.; Tarlochan, F.
2015-12-01
Search for new geometries and materials that would serve in crashworthiness applications is a cumulative process. Recent studies investigated the performance of expanded metal tubes and the possible ways to enhance its energy absorption capability. The aim of this work is to investigate the crashworthiness characteristics of new concept is proposed where expanded metal tube is suited into a double-walled tube made of the same material to form one structure. The tube was then numerically tested through a verified model using ABAQUS software. Moreover, the influence of the size of the expanded metal cell was also investigated in the present study. The new concept showed an enhanced energy absorption characteristics related to the change in the mass of the tubular structure. The enhancement was related to both the change in deformation pattern, and the increase in crushed mass.
Analysis for the Progressive Failure Response of Textile Composite Fuselage Frames
NASA Technical Reports Server (NTRS)
Johnson, Eric R.; Boitnott, Richard L. (Technical Monitor)
2002-01-01
A part of aviation accident mitigation is a crashworthy airframe structure, and an important measure of merit for a crashworthy structure is the amount of kinetic energy that can be absorbed in the crush of the structure. Prediction of the energy absorbed from finite element analyses requires modeling the progressive failure sequence. Progressive failure modes may include material degradation, fracture and crack growth, and buckling and collapse. The design of crashworthy airframe components will benefit from progressive failure analyses that have been validated by tests. The subject of this research is the development of a progressive failure analysis for a textile composite, circumferential fuselage frame subjected to a quasi-static, crash-type load. The test data for the frame are reported, and these data are used to develop and to validate methods for the progressive failure response.
Directions for computational mechanics in automotive crashworthiness
NASA Technical Reports Server (NTRS)
Bennett, James A.; Khalil, T. B.
1993-01-01
The automotive industry has used computational methods for crashworthiness since the early 1970's. These methods have ranged from simple lumped parameter models to full finite element models. The emergence of the full finite element models in the mid 1980's has significantly altered the research direction. However, there remains a need for both simple, rapid modeling methods and complex detailed methods. Some directions for continuing research are discussed.
Directions for computational mechanics in automotive crashworthiness
NASA Astrophysics Data System (ADS)
Bennett, James A.; Khalil, T. B.
1993-08-01
The automotive industry has used computational methods for crashworthiness since the early 1970's. These methods have ranged from simple lumped parameter models to full finite element models. The emergence of the full finite element models in the mid 1980's has significantly altered the research direction. However, there remains a need for both simple, rapid modeling methods and complex detailed methods. Some directions for continuing research are discussed.
Storvik, Steven G; Campbell, Julius Q; Wheeler, Jeffrey B
2017-06-01
Rates of death because of asphyxia in motor vehicle crashes have been previously estimated using county and statewide data sets, but national estimates have not been reported. The literature regarding asphyxia in motor vehicle crashes primarily involves discussions about clinical findings, and crash-related variables have been sparsely reported. The current study calculated a nationwide fatality rate for asphyxia in motor vehicle crashes of 1.4%. Seventeen case studies of asphyxia were also reported providing crash-, vehicle-, and occupant-related variables. These included type of accident, crash severity, seat belt use, containment status, extent of occupant compartment intrusion, height, weight, and injury pattern. The data presented can be used to better understand the injury mechanism, identify risk factors, develop possible protective countermeasures, and create situational awareness for emergency responders and investigators.
Crashworthy railing for timber bridges
Michael A. Ritter; Ronald K. Faller; Sheila Rimal Duwadi
1999-01-01
Bridge railing systems in the United States have historically beers designed based on static load criteria given in the American Association of State Highway and Transportation 0fficials (AASHTO) Standard Specifications for Highway Bridges. In the past decade, full-scale vehicle crash testing has been recognized as a more appropriate and reliable method of evaluating...
Stutts, J C; Reinfurt, D W; Rodgman, E A
2001-01-01
Five years (1995-1999) of national Crashworthiness Data System (CDS) data are analyzed to determine the role of driver distraction in traffic crashes and the specific sources of this distraction. Results show that 8.3 percent of the drivers were distracted at the time of their crash; after adjustment for the large percentage of drivers with unknown distraction status, the percentage rose to 12.9 percent. The most frequently cited sources of driver distraction were persons, objects or events outside the vehicle (29.4% of distracted drivers), adjusting the radio, tape or CD player (11.4%), and other occupants in the vehicle (10.9%). Other specific distractions (moving objects in vehicle, other objects brought into vehicle, adjusting vehicle or climate controls, eating and drinking, cell phones, and smoking) were each cited in only one to four percent of the cases. The likelihood of being distracted and the source of distraction varied by driver age but not by gender. Results are discussed in light of the limitations inherent in the CDS and other crash data, and the need for expanded data collection initiatives.
Injury severity data for front and second row passengers in frontal crashes.
Atkinson, Theresa; Leszek Gawarecki; Tavakoli, Massoud
2016-06-01
The data contained here were obtained from the National Highway Transportation Safety Administration׳s National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the years 2008-2014. This publically available data set monitors motor vehicle crashes in the United States, using a stratified random sample frame, resulting in information on approximately 5000 crashes each year that can be utilized to create national estimates for crashes. The NASS-CDS data sets document vehicle, crash, and occupant factors. These data can be utilized to examine public health, law enforcement, roadway planning, and vehicle design issues. The data provided in this brief are a subset of crash events and occupants. The crashes provided are exclusively frontal crashes. Within these crashes, only restrained occupants who were seated in the right front seat position or the second row outboard seat positions were included. The front row and second row data sets were utilized to construct occupant pairs crashes where both a right front seat occupant and a second row occupant were available. Both unpaired and paired data sets are provided in this brief.
Injury severity data for front and second row passengers in frontal crashes
Atkinson, Theresa; Leszek Gawarecki; Tavakoli, Massoud
2016-01-01
The data contained here were obtained from the National Highway Transportation Safety Administration׳s National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) for the years 2008–2014. This publically available data set monitors motor vehicle crashes in the United States, using a stratified random sample frame, resulting in information on approximately 5000 crashes each year that can be utilized to create national estimates for crashes. The NASS-CDS data sets document vehicle, crash, and occupant factors. These data can be utilized to examine public health, law enforcement, roadway planning, and vehicle design issues. The data provided in this brief are a subset of crash events and occupants. The crashes provided are exclusively frontal crashes. Within these crashes, only restrained occupants who were seated in the right front seat position or the second row outboard seat positions were included. The front row and second row data sets were utilized to construct occupant pairs crashes where both a right front seat occupant and a second row occupant were available. Both unpaired and paired data sets are provided in this brief. PMID:27077084
Innovative Anti Crash Absorber for a Crashworthy Landing Gear
NASA Astrophysics Data System (ADS)
Guida, Michele; Marulo, Francesco; Montesarchio, Bruno; Bruno, Massimiliano
2014-06-01
This paper defines an innovative concept to anti-crash absorber in composite material to be integrated on the landing gear as an energy-absorbing device in crash conditions to absorb the impact energy. A composite cylinder tube in carbon fiber material is installed coaxially to the shock absorber cylinder and, in an emergency landing gear condition, collapses in order to enhance the energy absorption performance of the landing system. This mechanism has been developed as an alternative solution to a high-pressure chamber installed on the Agusta A129 CBT helicopter, which can be considered dangerous when the helicopter operates in hard and/or crash landing. The characteristics of the anti-crash device are presented and the structural layout of a crashworthy landing gear adopting the developed additional energy absorbing stage is outlined. Experimental and numerical results relevant to the material characterization and the force peaks evaluation of the system development are reported. The anti-crash prototype was designed, analysed, optimized, made and finally the potential performances of a landing gear with the additional anti-crash absorber system are tested by drop test and then correlated with a similar test without the anti-crash system, showing that appreciable energy absorbing capabilities and efficiencies can be obtained in crash conditions.
Frontal crashworthiness characterisation of a vehicle segment using curve comparison metrics.
Abellán-López, D; Sánchez-Lozano, M; Martínez-Sáez, L
2018-08-01
The objective of this work is to propose a methodology for the characterization of the collision behaviour and crashworthiness of a segment of vehicles, by selecting the vehicle that best represents that group. It would be useful in the development of deformable barriers, to be used in crash tests intended to study vehicle compatibility, as well as for the definition of the representative standard pulses used in numerical simulations or component testing. The characterisation and selection of representative vehicles is based on the objective comparison of the occupant compartment acceleration and barrier force pulses, obtained during crash tests, by using appropriate comparison metrics. This method is complemented with another one, based exclusively on the comparison of a few characteristic parameters of crash behaviour obtained from the previous curves. The method has been applied to different vehicle groups, using test data from a sample of vehicles. During this application, the performance of several metrics usually employed in the validation of simulation models have been analysed, and the most efficient ones have been selected for the task. The methodology finally defined is useful for vehicle segment characterization, taken into account aspects of crash behaviour related to the shape of the curves, difficult to represent by simple numerical parameters, and it may be tuned in future works when applied to larger and different samples. Copyright © 2018 Elsevier Ltd. All rights reserved.
Lai, Xinghua; Ma, Chunsheng; Hu, Jingwen; Zhou, Qing
2012-09-01
Occupant injury in real world vehicle accidents can be significantly affected by a set of crash characteristics, of which impact direction and impact location (or damage location) in general scale interval (e.g., frontal impact is frequently defined as general damage to vehicle frontal end with impact angle range of 11-1 o'clock) have been identified to associate with injury outcome. The effects of crash configuration in more specific scale of interval on the injury characteristics have not been adequately investigated. This paper presents a statistical analysis to investigate the combined effects of specific impact directions and impact locations on the serious-to-fatal injuries of driver occupants involved in near-side collisions using crash data from National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) for the calendar years of 1995-2005. The screened injury dataset is categorized by three impact locations (side front, side center and side distributed) and two impact directions (oblique impact at 10 o'clock and pure lateral impact at 9 o'clock), resulting in six crash configurations in total. The weighted counts and the risks of different types of injuries in each subgroup are calculated, with which the relative risks along with 95% confidence intervals under oblique impacts versus lateral impacts in each impact location category are computed. Accordingly, the most frequent injury patterns, the risks and the coded-sources of serious thoracic injuries in different crash configurations are identified. The approach adopted in the present study provides new perspectives into occupant injury outcomes and associated mechanism. Results of the analyses reveal the importance of consideration of the crash configurations beyond the scope of existing side-impact regulatory tests and stress the necessity of vehicle crashworthiness and restraint system design in omni-direction to better protect occupants in real-world crash scenarios. Copyright © 2012 Elsevier Ltd. All rights reserved.
AGARD (Advisory Group for Aerospace Research & Development) Index of Publications, 1980-1982.
1984-01-01
anthropometric dummy. The shoulder rotation mechanism with good crashworthy features which car be strap of the seat belt was pulled various distances up to...nr orgo ". g~aion Systems criteria for noodling goalies of Roof-time sIMUlation An) roitspensabre trot oon’us,.r * lr-, r’ihr.--r~ ;r rpriscr
Plans for crash-tested bridge railings for longitudinal wood decks on low-volume roads
Michael A. Ritter; Ronald K. Faller; Steve Bunnell; Paula D. Hilbrich Lee; Barry T. Rosson
1998-01-01
The plans for crashworthy bridge railings for low-volume roads were developed through a cooperative research program involving the USDA Forest Service, Forest Products Laboratory (FPL); the Midwest Roadside Safety Facility, University of Nebraska-Lincoln (MwRSF); and the Forest Service, National Forest System, Engineering. Three railings were developed and successfully...
Computational Methods for Crashworthiness
NASA Technical Reports Server (NTRS)
Noor, Ahmed K. (Compiler); Carden, Huey D. (Compiler)
1993-01-01
Presentations and discussions from the joint UVA/NASA Workshop on Computational Methods for Crashworthiness held at Langley Research Center on 2-3 Sep. 1992 are included. The presentations addressed activities in the area of impact dynamics. Workshop attendees represented NASA, the Army and Air Force, the Lawrence Livermore and Sandia National Laboratories, the aircraft and automotive industries, and academia. The workshop objectives were to assess the state-of-technology in the numerical simulation of crash and to provide guidelines for future research.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jones, N.; Wierzbicki, T.
1983-01-01
Behind the quest for safety in all forms of transport lies a complex technology of which structural crashworthiness forms an important part. This volume contains the work of over twenty experts whose interests range from the fundamental principles of structural collapse to the application of those principles to the design of ships, aircraft, road vehicles, and rail vehicles. The text focuses on the application of analytical and experimental techniques to predict energy dissipation characteristics of thin-walled structures and structural members under quasi-static and dynamic loadings.
Helicopter crashworthiness research program
NASA Technical Reports Server (NTRS)
Farley, Gary L.; Boitnott, Richard L.; Carden, Huey D.
1988-01-01
Results are presented from the U.S. Army-Aerostructures Directorate/NASA-Langley Research Center joint research program on helicopter crashworthiness. Through the on-going research program an in-depth understanding was developed on the cause/effect relationships between material and architectural variables and the energy-absorption capability of composite material and structure. Composite materials were found to be efficient energy absorbers. Graphite/epoxy subfloor structures were more efficient energy absorbers than comparable structures fabricated from Kevlar or aluminum. An accurate method predicting the energy-absorption capability of beams was developed.
Structural design and crashworthiness of automobiles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Murthy, T.K.S.; Brebbia, C.A.
1987-01-01
This book contains contributions on the design of automobile structure, particularly from the viewpoint of its crashworthiness, which is an essential feature for the safety of passengers and other road users. The book provides a work of reference on the design of automobile structures and the papers included are the edited versions of some of the papers presented at the 1st International Conference on Computer Aided Design, Manufacture and Operation in the Automotive Industries (COMPAUTO 87) organized by the Computational Mechanics Institute of Southampton, England.
Glatz Prototype Seat Impact Testing
2013-07-03
airbag restraint, H-60A/L, crashworthiness, crashworthy, helicopter, rotorcraft, occupant restraint 16. SECURITY CLASSIFICATION OF: 17...data for Cell C, incorporating the H-60 Comp data, the new Glatz prototype data, and data from the airbag restraint program with a modified H-60A/L seat...1711 GLATZ VDT6290 Glatz 24.37 40.52 YES 922 42.40 1732 AIRBAG VDT6287 H-60A/L w/crotch strap mod 21.39* 40.56 YES 1267 21.27 1373 *Issue with
Investigation of 14.5mm API Self-Sealing/Crashworthy Fuel Tank Material
1974-09-01
describes the results of a f-rogram for a crashworthy, 14.5mm API tolerant fuel cell construction developed and subjected co qualification testing. The...Paragraphs 4.6.6.4 and 4.6.6.5), which were not required by contract. Two fuel tanks were built of a construction designated by The Goodyear Tire & Rubber...TABLES 3 INTRODUCTION 4 FUEL TANK MATERIAL DESIGN STUDY (TASK I) 4 QUALIFIC/.TION OF CONSTRUCTION (TASK 11) ........ 5 FUEL TANK GUNFIRE 12
ERIC Educational Resources Information Center
Schneider, Lawrence W.; Manary, Miriam A.; Hobson, Douglas A.
2008-01-01
Safe transportation for wheelchair users who do not transfer to the vehicle seat when traveling in motor vehicles requires after-market wheelchair tiedown and occupant restraint systems (WTORS) to secure the wheelchair and provide crashworthy restraint for the wheelchair-seated occupant. In the absence of adequate government safety standards,…
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.
Zhou, Hanzhi; Elliott, Michael R; Raghunathan, Trivellore E
2016-06-01
Multistage sampling is often employed in survey samples for cost and convenience. However, accounting for clustering features when generating datasets for multiple imputation is a nontrivial task, particularly when, as is often the case, cluster sampling is accompanied by unequal probabilities of selection, necessitating case weights. Thus, multiple imputation often ignores complex sample designs and assumes simple random sampling when generating imputations, even though failing to account for complex sample design features is known to yield biased estimates and confidence intervals that have incorrect nominal coverage. In this article, we extend a recently developed, weighted, finite-population Bayesian bootstrap procedure to generate synthetic populations conditional on complex sample design data that can be treated as simple random samples at the imputation stage, obviating the need to directly model design features for imputation. We develop two forms of this method: one where the probabilities of selection are known at the first and second stages of the design, and the other, more common in public use files, where only the final weight based on the product of the two probabilities is known. We show that this method has advantages in terms of bias, mean square error, and coverage properties over methods where sample designs are ignored, with little loss in efficiency, even when compared with correct fully parametric models. An application is made using the National Automotive Sampling System Crashworthiness Data System, a multistage, unequal probability sample of U.S. passenger vehicle crashes, which suffers from a substantial amount of missing data in "Delta-V," a key crash severity measure.
Zhou, Hanzhi; Elliott, Michael R.; Raghunathan, Trivellore E.
2017-01-01
Multistage sampling is often employed in survey samples for cost and convenience. However, accounting for clustering features when generating datasets for multiple imputation is a nontrivial task, particularly when, as is often the case, cluster sampling is accompanied by unequal probabilities of selection, necessitating case weights. Thus, multiple imputation often ignores complex sample designs and assumes simple random sampling when generating imputations, even though failing to account for complex sample design features is known to yield biased estimates and confidence intervals that have incorrect nominal coverage. In this article, we extend a recently developed, weighted, finite-population Bayesian bootstrap procedure to generate synthetic populations conditional on complex sample design data that can be treated as simple random samples at the imputation stage, obviating the need to directly model design features for imputation. We develop two forms of this method: one where the probabilities of selection are known at the first and second stages of the design, and the other, more common in public use files, where only the final weight based on the product of the two probabilities is known. We show that this method has advantages in terms of bias, mean square error, and coverage properties over methods where sample designs are ignored, with little loss in efficiency, even when compared with correct fully parametric models. An application is made using the National Automotive Sampling System Crashworthiness Data System, a multistage, unequal probability sample of U.S. passenger vehicle crashes, which suffers from a substantial amount of missing data in “Delta-V,” a key crash severity measure. PMID:29226161
Boyd, Douglas D
2015-06-01
Towards further improving general aviation aircraft crashworthiness, multi-axis dynamic tests have been required for aircraft certification (14CFR23.562) since 1985. The objective of this study was to determine if occupants in aircraft certified to these higher crashworthiness standards show a mitigated fraction of fatal accidents and/or injury severity. The NTSB aviation database was queried for accidents occurring between 2002 and 2012 involving aircraft certified to, or immune from, dynamic crash testing and manufactured after 1999. Only operations conducted under 14CFR Part 91 were considered. Statistical analysis employed proportion tests and logistic regression. Off-airport landings are associated with high decelerative forces; however for off-airport landings, the fraction of fatal accidents for aircraft subject to, or exempt from, dynamic crash testing was similar (0.53 and 0.60, respectively). Unexpectedly, for on-airport landings a higher fraction of fatalities was evident for aircraft whose certification mandated dynamic crash testing. Improved crashworthiness standards would be expected to translate into a reduced severity of accident injuries. For all accidents, as well as for those deemed survivable, the fraction of minor and serious injuries was reduced for occupants in aircraft certified to the higher crashworthiness standards. Surprisingly, the fraction of occupants fatally injured was not decreased for aircraft subject to dynamic crash tests. To shed light on this unexpected finding flight history, airman demographics and post-impact fires for aircraft for which dynamic crash testing is mandatory or exempt was examined. For the former cohort the median distance of the accident flight was nearly 44% higher. Aircraft subject to dynamic crash testing were also involved in a greater fraction (0.25 versus 0.12, respectively) of post-impact fires. Our data suggest that while the more stringent crashworthiness standards have mitigated minor and serious injuries, surprisingly the fraction of occupants fatally injured is unaltered. The unchanged fraction of fatal injuries may reflect partly (a) fatigue associated with longer flight distances and (b) a greater proportion of post-impact fires. Copyright © 2015 Elsevier Ltd. All rights reserved.
Motor vehicle technology:Mobility for prosperity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1985-01-01
This book presents the papers given at a conference on internal combustion engines for vehicles. Topics considered at the conference included combustion chambers, the lubrication of turbocharged engines, oil filters, fuel consumption, traffic control, crashworthiness, brakes, acceleration, unleaded gasoline, methanol fuels, pressure drop, safety regulations, tire vibration, detergents, fuel economy, ceramics in engines, steels, catalytic converters, fuel additives, heat exchangers, pump systems, emissions control, fuel injection systems, noise pollution control, natural gas fuels, assembly plant productivity, aerodynamics, torsion, electronics, and automatic transmissions.
Evaluation of wheelchair sling seat and sling back crashworthiness.
Ha, D; Bertocci, G; Karg, P; Deemer, E
2002-07-01
Many wheelchairs are used as vehicle seats by those who cannot transfer to a vehicle seat. Although ANSI/RESNA WC-19 has been recently adopted as a standard to evaluate crashworthiness of the wheelchairs used as motor vehicle seats, replacement or after-market seats may not be tested to this standard. This study evaluated the crashworthiness of two specimens each of three unique sling backs and three unique sling seats using a static test procedure intended to simulate crash loading conditions. To pass the test, a sling back is required to withstand a 2290 lb load, and a sling seat should be capable of withstanding a 3750 lb load. All, but two sling back specimens which failed at 1567 lb and 1787 lb, withstood the test criterion load. Two of six tested sling seats failed to pass the test: one failed at 3123 lb and the other failed to sustain the load for 5 s although it reached the test criterion load. Most of the failures occurred at the seams of the side openings of upholsteries where the wheelchair frame inserts for attachment.
NASA Astrophysics Data System (ADS)
Henn, Philipp; Liewald, Mathias; Sindel, Manfred
2018-05-01
As lightweight design as well as crash performance are crucial to future car body design, exact material characterisation is important to use materials at their full potential and reach maximum efficiency. Within the scope of this paper, the potential of newly established bending-tension test procedure to characterise material crashworthiness is investigated. In this test setup for the determination of material failure, a buckling-bending test is coupled with a subsequent tensile test. If prior bending load is critical, tensile strength and elongation in the subsequent tensile test are dramatically reduced. The new test procedure therefore offers an applicable definition of failure as the incapacity of energy consumption in subsequent phases of the crash represents failure of a component. In addition to that, the correlation of loading condition with actual crash scenarios (buckling and free bending) is improved compared to three- point bending test. The potential of newly established bending-tension test procedure to characterise material crashworthiness is investigated in this experimental studys on two aluminium sheet alloys. Experimental results are validated with existing ductility characterisation from edge compression test.
Modeling, simulation and optimization approaches for design of lightweight car body structures
NASA Astrophysics Data System (ADS)
Kiani, Morteza
Simulation-based design optimization and finite element method are used in this research to investigate weight reduction of car body structures made of metallic and composite materials under different design criteria. Besides crashworthiness in full frontal, offset frontal, and side impact scenarios, vibration frequencies, static stiffness, and joint rigidity are also considered. Energy absorption at the component level is used to study the effectiveness of carbon fiber reinforced polymer (CFRP) composite material with consideration of different failure criteria. A global-local design strategy is introduced and applied to multi-objective optimization of car body structures with CFRP components. Multiple example problems involving the analysis of full-vehicle crash and body-in-white models are used to examine the effect of material substitution and the choice of design criteria on weight reduction. The results of this study show that car body structures that are optimized for crashworthiness alone may not meet the vibration criterion. Moreover, optimized car body structures with CFRP components can be lighter with superior crashworthiness than the baseline and optimized metallic structures.
Research of a Tram Headstock from Composite
NASA Astrophysics Data System (ADS)
Malkovsky, Zdenek; Kovandova, Hedvika
2014-08-01
The requirements for crashworthiness of railway vehicles are defined by the Railroad crashworthiness standard EN 15227. This standard is based on the findings of the characteristics of steel structures of front parts of railway vehicles. In the Czech Republic an extensive research was carried out within the project TIP FR-TI1/113 on application of composite sandwich structure elements in the design of the front cabins of a railway vehicle. The aim of the research work was to determine real possibilities of the composite sandwich structures for use in the construction of railway vehicles while considering the validity of the above-mentioned standard.
Near-term hybrid vehicle program, phase 1. Appendix C: Preliminary design data package
NASA Technical Reports Server (NTRS)
1979-01-01
The design methodology, the design decision rationale, the vehicle preliminary design summary, and the advanced technology developments are presented. The detailed vehicle design, the vehicle ride and handling and front structural crashworthiness analysis, the microcomputer control of the propulsion system, the design study of the battery switching circuit, the field chopper, and the battery charger, and the recent program refinements and computer results are presented.
The potential for further development of passive safety.
Frampton, Richard; Lenard, James
2009-10-01
In Europe, emphasis is being transferred from injury prevention to accident prevention to reduce road casualties. This study attempted to identify the current potential for serious casualty reduction using passive safety by examining the crash performance of new cars with seriously injured occupants. The Co-operative Crash Injury Study conducts in-depth investigations of around 1200 vehicles per year from seven sample regions around England. Attention was focussed on passenger cars manufactured from 2004 to 2008 with at least one occupant injured to AIS level 3 or more. 28% of MAIS 3+ occupants were unbelted and 40% were belted but involved in crashes with limited potential for passive protection. A further 32% of occupants were belted and involved in crashes with potential for improved crashworthiness design. For these occupants, five major functional requirements were identified for crashworthiness improvement: a reduction of seatbelt loads on the chest and abdomen in frontal crashes, particularly for seniors; reduction in femur and tibia loads in frontal crashes; provision of head and chest protection in near-side crashes; and reduction of occupant lateral excursion in far-side impacts. Together these functions accounted for 70% of the identified requirements. Other smaller requirements were identified, each contributing up to 5% of total. Overall, the case supporting further developments in passive safety still appears significant.
The Potential for Further Development of Passive Safety
Frampton, Richard; Lenard, James
2009-01-01
In Europe, emphasis is being transferred from injury prevention to accident prevention to reduce road casualties. This study attempted to identify the current potential for serious casualty reduction using passive safety by examining the crash performance of new cars with seriously injured occupants. The Co-operative Crash Injury Study conducts in-depth investigations of around 1200 vehicles per year from seven sample regions around England. Attention was focussed on passenger cars manufactured from 2004 to 2008 with at least one occupant injured to AIS level 3 or more. 28% of MAIS 3+ occupants were unbelted and 40% were belted but involved in crashes with limited potential for passive protection. A further 32% of occupants were belted and involved in crashes with potential for improved crashworthiness design. For these occupants, five major functional requirements were identified for crashworthiness improvement: a reduction of seatbelt loads on the chest and abdomen in frontal crashes, particularly for seniors; reduction in femur and tibia loads in frontal crashes; provision of head and chest protection in near-side crashes; and reduction of occupant lateral excursion in far-side impacts. Together these functions accounted for 70% of the identified requirements. Other smaller requirements were identified, each contributing up to 5% of total. Overall, the case supporting further developments in passive safety still appears significant. PMID:20184832
ICME for Crashworthiness of TWIP Steels: From Ab Initio to the Crash Performance
NASA Astrophysics Data System (ADS)
Güvenç, O.; Roters, F.; Hickel, T.; Bambach, M.
2015-01-01
During the last decade, integrated computational materials engineering (ICME) emerged as a field which aims to promote synergetic usage of formerly isolated simulation models, data and knowledge in materials science and engineering, in order to solve complex engineering problems. In our work, we applied the ICME approach to a crash box, a common automobile component crucial to passenger safety. A newly developed high manganese steel was selected as the material of the component and its crashworthiness was assessed by simulated and real drop tower tests. The crashworthiness of twinning-induced plasticity (TWIP) steel is intrinsically related to the strain hardening behavior caused by the combination of dislocation glide and deformation twinning. The relative contributions of those to the overall hardening behavior depend on the stacking fault energy (SFE) of the selected material. Both the deformation twinning mechanism and the stacking fault energy are individually well-researched topics, but especially for high-manganese steels, the determination of the stacking-fault energy and the occurrence of deformation twinning as a function of the SFE are crucial to understand the strain hardening behavior. We applied ab initio methods to calculate the stacking fault energy of the selected steel composition as an input to a recently developed strain hardening model which models deformation twinning based on the SFE-dependent dislocation mechanisms. This physically based material model is then applied to simulate a drop tower test in order to calculate the energy absorption capacity of the designed component. The results are in good agreement with experiments. The model chain links the crash performance to the SFE and hence to the chemical composition, which paves the way for computational materials design for crashworthiness.
Experimental investigation of the crashworthiness of scaled composite sailplane fuselages
NASA Technical Reports Server (NTRS)
Kampf, Karl-Peter; Crawley, Edward F.; Hansman, R. John, Jr.
1989-01-01
The crash dynamics and energy absorption of composite sailplane fuselage segments undergoing nose-down impact were investigated. More than 10 quarter-scale structurally similar test articles, typical of high-performance sailplane designs, were tested. Fuselages segments were fabricated of combinations of fiberglass, graphite, Kevlar, and Spectra fabric materials. Quasistatic and dynamic tests were conducted. The quasistatic tests were found to replicate the strain history and failure modes observed in the dynamic tests. Failure modes of the quarter-scale model were qualitatively compared with full-scale crash evidence and quantitatively compared with current design criteria. By combining material and structural improvements, substantial increases in crashworthiness were demonstrated.
An adaptive response surface method for crashworthiness optimization
NASA Astrophysics Data System (ADS)
Shi, Lei; Yang, Ren-Jye; Zhu, Ping
2013-11-01
Response surface-based design optimization has been commonly used for optimizing large-scale design problems in the automotive industry. However, most response surface models are built by a limited number of design points without considering data uncertainty. In addition, the selection of a response surface in the literature is often arbitrary. This article uses a Bayesian metric to systematically select the best available response surface among several candidates in a library while considering data uncertainty. An adaptive, efficient response surface strategy, which minimizes the number of computationally intensive simulations, was developed for design optimization of large-scale complex problems. This methodology was demonstrated by a crashworthiness optimization example.
Energy absorption in composite materials for crashworthy structures
NASA Technical Reports Server (NTRS)
Farley, Gary L.
1987-01-01
Crash energy-absorption processes in composite materials have been studied as part of a research program aimed at the development of energy absorbing subfloor beams for crashworthy military helicopters. Based on extensive tests on glass/epoxy, graphite/epoxy, and Kevlar/epoxy composites, it is shown that the energy-absorption characteristics and crushing modes of composite beams are similar to those exhibited by tubular specimens of similar material and architecture. The crushing mechanisms have been determined and related to the mechanical properties of the constituent materials and specimen architecture. A simple and accurate method for predicting the energy-absorption capability of composite beams has been developed.
Structural safety assessment for FLNG-LNGC system during offloading operation scenario
NASA Astrophysics Data System (ADS)
Hu, Zhi-qiang; Zhang, Dong-wei; Zhao, Dong-ya; Chen, Gang
2017-04-01
The crashworthiness of the cargo containment systems (CCSs) of a floating liquid natural gas (FLNG) and the side structures in side-by-side offloading operations scenario are studied in this paper. An FLNG vessel is exposed to potential threats from collisions with a liquid natural gas carrier (LNGC) during the offloading operations, which has been confirmed by a model test of FLNG-LNGC side-by-side offloading operations. A nonlinear finite element code LS-DYNA is used to simulate the collision scenarios during the offloading operations. Finite element models of an FLNG vessel and an LNGC are established for the purpose of this study, including a detailed LNG cargo containment system in the FLNG side model. Based on the parameters obtained from the model test and potential dangerous accidents, typical collision scenarios are defined to conduct a comprehensive study. To evaluate the safety of the FLNG vessel, a limit state is proposed based on the structural responses of the LNG CCS. The different characteristics of the structural responses for the primary structural components, energy dissipation and collision forces are obtained for various scenarios. Deformation of the inner hull is found to have a great effect on the responses of the LNG CCS, with approximately 160 mm deformation corresponding to the limit state. Densely arranged web frames can absorb over 35% of the collision energy and be proved to greatly enhance the crashworthiness of the FLNG side structures.
Secondary Collisions Following a Traffic Barrier Impact: Frequency, Factors, and Occupant Risk
Gabauer, Douglas J.
2010-01-01
This study has investigated secondary collisions following an initial barrier impact in tow-away level crashes. The analysis included 2026 barrier impact cases that were selected from 12-years of in-depth crash data available through the National Automotive Sampling System (NASS) / Crashworthiness Data System (CDS). Secondary collisions were found to occur in approximately one-third of tow-away level crashes where a traffic barrier was the first object struck. Secondary crashes were found to primarily involve an impact to another vehicle, an impact to another barrier, or a rollover; tree and pole impacts were found to represent a much smaller proportion of secondary impacts. Through a detailed analysis of vehicle trajectory, this study supports previous research suggesting secondary collision risk is substantial even for vehicles not ultimately involved in a secondary collision. Compared to a single barrier impact, the occurrence of a secondary collision was found to increase the risk of serious occupant injury by a factor of 3.5, equivalent to the serious injury risk difference found between a belted and unbelted occupant in a traffic barrier crash. PMID:21050605
Safety Changes in the US Vehicle Fleet since Model Year 1990, Based on NASS Data
Eigen, Ana Maria; Digges, Kennerly; Samaha, Randa Radwan
2012-01-01
Based on the National Automotive Sampling System Crashworthiness Data System since the 1988–1992 model years, there has been a reduction in the MAIS 3+ injury rate and the Mean HARM for all crash modes. The largest improvement in vehicle safety has been in rollovers. There was an increase in the rollover injury rate in the 1993–1998 model year period, but a reduction since then. When comparing vehicles of the model year 1993 to 1998 with later model vehicles, the most profound difference was the reduction of rollover frequency for SUV’s – down more than 20% when compared to other crash modes. When considering only model years since 2002 the rollover frequency reduction was nearly 40%. A 26% reduction in the rate of moderate and serious injuries for all drivers in rollovers was observed for the model years later than 1998. The overall belt use rate for drivers of late model vehicles with HARM weighted injuries was 62% - up from 54% in earlier model vehicles. However, in rollover crashes, the same belt use rate lagged at 54%. PMID:23169134
Ju, Yong Han; Sohn, So Young
2011-01-01
Injury analysis following a vehicle crash is one of the most important research areas. However, most injury analyses have focused on one-dimensional injury variables, such as the AIS (Abbreviated Injury Scale) or the IIS (Injury Impairment Scale), at a time in relation to various traffic accident factors. However, these studies cannot reflect the various injury phenomena that appear simultaneously. In this paper, we apply quantification method II to the NASS (National Automotive Sampling System) CDS (Crashworthiness Data System) to find the relationship between the categorical injury phenomena, such as the injury scale, injury position, and injury type, and the various traffic accident condition factors, such as speed, collision direction, vehicle type, and seat position. Our empirical analysis indicated the importance of safety devices, such as restraint equipment and airbags. In addition, we found that narrow impact, ejection, air bag deployment, and higher speed are associated with more severe than minor injury to the thigh, ankle, and leg in terms of dislocation, abrasion, or laceration. Copyright © 2010 Elsevier Ltd. All rights reserved.
Robertson, L S
1996-01-01
OBJECTIVES. Two phases of attempts to improve passenger car crash worthiness have occurred: minimum safety standards and publicized crash tests. This study evaluated these attempts, as well as changes in seat belt and alcohol use, in terms of their effect on occupant death and fatal crash rates. METHODS. Data on passenger car occupant fatalities and total involvement in fatal crashes, for 1975 through 1991, were obtained from the Fatal Accident Reporting System. Rates per mile were calculated through published sources on vehicle use by vehicle age. Regression estimates of effects of regulation, publicized crash tests, seat belt use and alcohol involvement were obtained. RESULTS. Substantial reductions in fatalities occurred in the vehicle model years from the late 1960s through most of the 1970s, when federal standards were applied. Some additional increments in reduced death rates, attributable to additional improved vehicle crashworthiness, occurred during the period of publicized crash tests. Increased seat belt use and reduced alcohol use also contributed significantly to reduced deaths. CONCLUSIONS. Minimum safety standards, crashworthiness improvements, seat belt use laws, and reduced alcohol use each contributed to a large reduction in passenger car occupant deaths. PMID:8561238
NASA Technical Reports Server (NTRS)
Fasanella, Edwin L.; Jackson, Karen E.
2002-01-01
A 25-ft/s vertical drop test of a composite fuselage section was conducted with two energy-absorbing seats occupied by anthropomorphic dummies to evaluate the crashworthy features of the fuselage section and to determine its interaction with the seats and dummies. The 5-ft. diameter fuselage section consists of a stiff structural floor and an energy-absorbing subfloor constructed of Rohacel foam blocks. The experimental data from this test were analyzed and correlated with predictions from a crash simulation developed using the nonlinear, explicit transient dynamic computer code, MSC.Dytran. The anthropomorphic dummies were simulated using the Articulated Total Body (ATB) code, which is integrated into MSC.Dytran.
NASA Technical Reports Server (NTRS)
Fasanella, Edwin L.; Jackson, Karen E.
2002-01-01
A 25-ft/s vertical drop test of a composite fuselage section was conducted with two energy-absorbing seats occupied by anthropomorphic dummies to evaluate the crashworthy features of the fuselage section and to determine its interaction with the seats and dummies. The 5-ft diameter fuselage section consists of a stiff structural floor and an energy-absorbing subfloor constructed of Rohacel foam blocks. The experimental data from this test were analyzed and correlated with predictions from a crash simulation developed using the nonlinear, explicit transient dynamic computer code, MSC.Dytran. The anthropomorphic dummies were simulated using the Articulated Total Body (ATB) code, which is integrated into MSC.Dytran.
Crashworthy Evaluation of a 1/5-Scale Model Composite Fuselage Concept
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Fasanella, Edwin L.
1999-01-01
A 1/5-scale model composite fuselage concept for light aircraft and rotorcraft has been developed to satisfy structural and flight loads requirements and to satisfy design goals for improved crashworthiness. The 1/5-scale model fuselage consists of a relatively rigid upper section which forms the passenger cabin, a stiff structural floor, and an energy absorbing subfloor which is designed to limit impact forces during a crash event. The focus of the present paper is to describe the crashworthy evaluation of the fuselage concept through impact testing and finite element simulation using the nonlinear, explicit transient dynamic code, MSC/DYTRAN. The energy absorption behavior of two different subfloor configurations was determined through quasi-static crushing tests. For the dynamic evaluation, each subfloor configuration was incorporated into a 1/5-scale model fuselage section, which was impacted at 31 ft/s vertical velocity onto a rigid surface. The experimental data demonstrate that the fuselage section with a foam-filled subfloor configuration satisfied the impact design requirement. In addition, the fuselage section maintained excellent energy absorption behavior for a 31 ft/s vertical drop test with a 15 deg-roll impact attitude. Good correlation was obtained between the experimental data and analytical results for both impact conditions.
Design of the Cross Section Shape of AN Aluminum Crash Box for Crashworthiness Enhancement of a CAR
NASA Astrophysics Data System (ADS)
Kim, S. B.; Huh, H.; Lee, G. H.; Yoo, J. S.; Lee, M. Y.
This paper deals with the crashworthiness of an aluminum crash box for an auto-body with the various shapes of cross section such as a rectangle, a hexagon and an octagon. First, crash boxes with various cross sections were tested with numerical simulation to obtain the energy absorption capacity and the mean load. In case of the simple axial crush, the octagon shape shows higher mean load and energy absorption than the other two shapes. Secondly, the crash boxes were assembled to a simplified auto-body model for the overall crashworthiness. The model consists of a bumper, crash boxes, front side members and a sub-frame representing the behavior of a full car at the low speed impact. The analysis result shows that the rectangular cross section shows the best performance as a crash box which deforms prior to the front side member. The hexagonal and octagonal cross sections undergo torsion and local buckling as the width of cross section decreases while the rectangular cross section does not. The simulation result of the rectangular crash box was verified with the experimental result. The simulation result shows close tendency in the deformed shape and the load-displacement curve to the experimental result.
Who can best influence the quality of teenagers' cars?
Keall, Michael D; Newstead, Stuart
2013-01-01
Because young drivers' vehicles have been found to offer poor occupant protection in many countries, this study sought to identify the most appropriate audience for information and publicity designed to change purchasing preferences to improve these vehicles and resultant injury outcomes. An analysis of New Zealand vehicles crashed by drivers aged 19 years or less linked to data on the owner of the vehicle was undertaken. Details on the crashed vehicles were merged with licensing information to identify the owner's age group. It was presumed that most vehicles driven by teens but owned by someone aged 30 to 59 would be owned by a parent of the teen. Only 14 percent of vehicles crashed by teens were owned by teens. Generally, older vehicles with poor crashworthiness were provided for the teenage driver, whatever the age group of the owner. However, cars crashed by teens but owned by their parents were on average almost 2 years younger and had relatively superior crashworthiness than the teenager-owned and crashed vehicles, although their crashworthiness was still poor compared to vehicles driven by older drivers. Evidently, parents are key people in making vehicle purchasing decisions regarding the cars that teenagers drive and should be the main audience for measures to improve the poor secondary safety performance of teenagers' vehicles.
NASA experiments onboard the controlled impact demonstration
NASA Technical Reports Server (NTRS)
Hayduk, R. J.; Alfaro-Bou, E.; Fasanella, E. L.
1985-01-01
The structural crashworthiness tests conducted by NASA on the December 1, 1984 controlled impact demonstration are discussed. The components and locations of the data acquisition and photographic systems developed by NASA to evaluate impact loads throughout the aircraft structure and the transmission of loads into the dummies are described. The effectiveness of the NASA designed absorbing seats and the vertical, longitudinal, and transverse impact loads are measured. Data that is extremely applicable to crash dynamics structural research was obtained by the data acquisition system and very low load levels were measured for the NASA energy absorbing seats.
Technical highlights in general aviation
NASA Technical Reports Server (NTRS)
Stickle, J. W.
1977-01-01
Improvements in performance, safety, efficiency, and emissions control in general aviation craft are reviewed. While change is slow, the U.S. industries still account for the bulk (90%) of the world's general aviation fleet. Advances in general aviation aerodynamics, structures and materials, acoustics, avionics, and propulsion are described. Supercritical airfoils, drag reduction design, stall/spin studies, crashworthiness and passenger safety, fiberglass materials, flight noise abatement, interior noise and vibration reduction, navigation systems, quieter and cleaner (reciprocating, turboprop, turbofan) engines, and possible benefits of the Global Position Satellite System to general aviation navigation are covered in the discussion. Some of the developments are illustrated.
Study on Collision of Ship Side Structure by Simplified Plastic Analysis Method
NASA Astrophysics Data System (ADS)
Sun, C. J.; Zhou, J. H.; Wu, W.
2017-10-01
During its lifetime, a ship may encounter collision or grounding and sustain permanent damage after these types of accidents. Crashworthiness has been based on two kinds of main methods: simplified plastic analysis and numerical simulation. A simplified plastic analysis method is presented in this paper. Numerical methods using the non-linear finite-element software LS-DYNA are conducted to validate the method. The results show that, as for the accuracy of calculation results, the simplified plasticity analysis are in good agreement with the finite element simulation, which reveals that the simplified plasticity analysis method can quickly and accurately estimate the crashworthiness of the side structure during the collision process and can be used as a reliable risk assessment method.
NASA Astrophysics Data System (ADS)
HuaZhi, Zhou; ZhiJin, Wang
2017-11-01
The intersection element is an important part of the helicopter subfloor structure. In order to improve the crashworthiness properties, the floor and the skin of the intersection element are replaced with foldcore sandwich structures. Foldcore is a kind of high-energy absorption structure. Compared with original structure, the new intersection element shows better buffering capacity and energy-absorption capacity. To reduce structure’s mass while maintaining the crashworthiness requirements satisfied, optimization of the intersection element geometric parameters is conducted. An optimization method using NSGA-II and Anisotropic Kriging is used. A significant CPU time saving can be obtained by replacing numerical model with Anisotropic Kriging surrogate model. The operation allows 17.15% reduce of the intersection element mass.
Real-world injury patterns associated with Hybrid III sternal deflections in frontal crash tests.
Brumbelow, Matthew L; Farmer, Charles M
2013-01-01
This study investigated the relationship between the peak sternal deflection measurements recorded by the Hybrid III 50th percentile male anthropometric test device (ATD) in frontal crash tests and injury and fatality outcomes for drivers in field crashes. ATD sternal deflection data were obtained from the Insurance Institute for Highway Safety's 64 km/h, 40 percent overlap crashworthiness evaluation tests for vehicles with seat belt crash tensioners, load limiters, and good-rated structure. The National Automotive Sampling System Crashworthiness Data System (NASS-CDS) was queried for frontal crashes of these vehicles in which the driver was restrained by a seat belt and air bag. Injury probability curves were calculated by frontal crash type using the injuries coded in NASS-CDS and peak ATD sternal deflection data. Fatality Analysis Reporting System (FARS) front-to-front crashes with exactly one driver death were also studied to determine whether the difference in measured sternal deflections for the 2 vehicles was related to the odds of fatality. For center impacts, moderate overlaps, and large overlaps in NASS-CDS, the probability of the driver sustaining an Abbreviated Injury Scale (AIS) score ≥ 3 thoracic injury, or any nonextremity AIS ≥ 3 injury, increased with increasing ATD sternal deflection measured in crash tests. For small overlaps, however, these probabilities decreased with increasing deflection. For FARS crashes, the fatally injured driver more often was in the vehicle with the lower measured deflection in crash tests (55 vs. 45%). After controlling for other factors, a 5-mm difference in measured sternal deflections between the 2 vehicles was associated with a fatality odds ratio of 0.762 for the driver in the vehicle with the greater deflection (95% confidence interval = 0.373, 1.449). Restraint systems that reduce peak Hybrid III sternal deflection in a moderate overlap crash test are beneficial in real-world crashes with similar or greater overlap but likely have a disbenefit in crashes with small overlap. This may occur because belt-force limiters employed to control deflections allow excursion that could produce contact with interior vehicle components in small overlaps, given the more oblique occupant motion and potential inboard movement of the air bag. Although based on a limited number of cases, this interpretation is supported by differences in skeletal fracture locations among drivers in crashes with different overlaps. Current restraint systems could be improved by designs that reduce sternal deflection in moderate and large overlap crashes without increasing occupant excursion in small overlap crashes.
Crashworthiness analysis on alternative square honeycomb structure under axial loading
NASA Astrophysics Data System (ADS)
Li, Meng; Deng, Zongquan; Guo, Hongwei; Liu, Rongqiang; Ding, Beichen
2013-07-01
Hexagonal metal honeycomb is widely used in energy absorption field for its special construction. However, many other metal honeycomb structures also show good energy absorption characteristics. Currently, most of the researches focus on hexagonal honeycomb, while few are performed into different honeycomb structures. Therefore, a new alternative square honeycomb is developed to expand the non-hexagonal metal honeycomb applications in the energy absorption fields with the aim of designing low mass and low volume energy absorbers. The finite element model of alternative square honeycomb is built to analyze its specific energy absorption property. As the diversity of honeycomb structure, the parameterized metal honeycomb finite element analysis program is conducted based on PCL language. That program can automatically create finite element model. Numerical results show that with the same foil thickness and cell length of metal honeycomb, the alternative square has better specific energy absorption than hexagonal honeycomb. Using response surface method, the mathematical formulas of honeycomb crashworthiness properties are obtained and optimization is done to get the maximum specific energy absorption property honeycomb. Optimal results demonstrate that to absorb same energy, alternative square honeycomb can save 10% volume of buffer structure than hexagonal honeycomb can do. This research is significant in providing technical support in the extended application of different honeycomb used as crashworthiness structures, and is absolutely essential in low volume and low mass energy absorber design.
NASA Astrophysics Data System (ADS)
Dlugosch, M.; Spiegelhalter, B.; Soot, T.; Lukaszewicz, D.; Fritsch, J.; Hiermaier, S.
2017-05-01
With car manufacturers simultaneously facing increasing passive safety and efficiency requirements, FRP-metal hybrid material systems are one way to design lightweight and crashworthy vehicle structures. Generic automotive hybrid structural concepts have been tested under crash loading conditions. In order to assess the state of overall damage and structural integrity, and primarily to validate simulation data, several NDT techniques have been assessed regarding their potential to detect common damage mechanisms in such hybrid systems. Significant potentials were found particularly in combining 3D-topography laser scanning and X-Ray imaging results. Ultrasonic testing proved to be limited by the signal coupling quality on damaged or curved surfaces.
NASA Technical Reports Server (NTRS)
Hall, D. S.
1980-01-01
A development program was developed to design and improve the Emergency Locator Transmitter (ELT) transmitter and to improve the installation in the aircraft and its activation subsystem. There were 1135 general aviation fixed wing aircraft accident files reviewed. A detailed description of the damage to the aircraft was produced. The search aspects of these accidents were studied. As much information as possible about the ELT units in these cases was collected. The data should assist in establishing installation and mounting criteria, better design standards for activation subsystems, and requirements for the new ELT system design in the area of crashworthiness.
Full-scale Transport Controlled Impact Demonstration Program
NASA Technical Reports Server (NTRS)
1987-01-01
The Federal Aviation Administration (FAA) and NASA conducted a full-scale air-to-surface impact-survivable impact demonstration with a remotely piloted transport aircraft on 1 December 1984, at Edwards Air Force Base, California. The test article consisted of experiments, special equipment, and supporting systems, such as antimisting kerosene (AMK), crashworthiness structural/restraint, analytical modeling, cabin fire safety, flight data recorders, post-impact investigation, instrumentation/data acquisition systems, remotely piloted vehicle/flight control systems, range and flight safety provisions, etc. This report describes the aircraft, experiments, systems, activities, and events which lead up to the Controlled Impact Demonstration (CID). An overview of the final unmanned remote control flight and sequence of impact events are delineated. Preliminary post CID observations are presented.
Impact behaviour of an innovative plasticized poly(vinyl chloride) for the automotive industry
NASA Astrophysics Data System (ADS)
Bernard, C. A.; Bahlouli, N.; Wagner-Kocher, C.; Ahzi, S.; Rémond, Y.
2015-09-01
Plasticized poly(vinyl chloride) (PPVC) is widely used in the automotive industry in the design of structural parts for crashworthiness applications. Thus, it is necessary to study and understand the influence of the mechanical response and mechanical properties of PPVC over a wide range of strain rate, from quasi-static to dynamic loadings. The process is also investigated using different sample thicknesses. In this work, the strain rate effect of a new PPVC is investigated over a wide range of strain rates at three temperatures and for three thicknesses. A modelling of the yield stress is also proposed. The numerical prediction is in good agreement with the experimental results.
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.
Signs on concrete median barriers.
DOT National Transportation Integrated Search
2013-04-01
Concrete median barriers have been used throughout the state as permanent and temporary barriers for providing separation of traffic. Typically, these barriers are tested and considered crashworthy through crash testing according to National Cooperat...
49 CFR 229.203 - Applicability.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Applicability. 229.203 Section 229.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
49 CFR 229.203 - Applicability.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Applicability. 229.203 Section 229.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
49 CFR 229.203 - Applicability.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Applicability. 229.203 Section 229.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
49 CFR 229.203 - Applicability.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Applicability. 229.203 Section 229.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
49 CFR 229.203 - Applicability.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Applicability. 229.203 Section 229.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
Structural Crashworthiness Standards Comparison: Grade Crossing Collision Scenarios
DOT National Transportation Integrated Search
2009-10-20
In support of the Federal Railroad Administrations (FRA) : Railroad Equipment Safety Program, American and European : grade-crossing collision scenarios were evaluated and : compared. Finite element analyses (FEA) were employed to : subject an FRA...
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.
Occupant Injury Severity and Accident Causes in Helicopter Emergency Medical Services (1983-2014).
Boyd, Douglas D; Macchiarella, Nickolas D
2016-01-01
Helicopter emergency medical services (HEMS) transport critically ill patients to/between emergency care facilities and operate in a hazardous environment: the destination site is often encumbered with obstacles, difficult to visualize at night, and lack instrument approaches for degraded visibility. The study objectives were to determine 1) HEMS accident rates and causes; 2) occupant injury severity profiles; and 3) whether accident aircraft were certified to the more stringent crashworthiness standards implemented two decades ago. The National Transportation Safety Board (NTSB) aviation accident database was used to identify HEMS mishaps for the years spanning 1983-2014. Contingency tables (Pearson Chi-square or Fisher's exact test) were used to determine differences in proportions. A generalized linear model (Poisson distribution) was used to determine if accident rates differed over time. While the HEMS accident rate decreased by 71% across the study period, the fraction of fatal accidents (36-50%) and the injury severity profiles were unchanged. None of the accident aircraft fully satisfied the current crashworthiness standards. Failure to clear obstacles and visual-to-instrument flight, the most frequent accident causes (37 and 26%, respectively), showed a downward trend, whereas accidents ascribed to aircraft malfunction showed an upward trend over time. HEMS operators should consider updating their fleet to the current, more stringent crashworthiness standards in an attempt to reduce injury severity. Additionally, toward further mitigating accidents ascribed to inadvertent visual-to-instrument conditions, HEMS aircraft should be avionics-equipped for instrument flight rules flight.
Crash Analysis of Automotive Chassis Structure Considering the Strain Hardening Effect
NASA Astrophysics Data System (ADS)
Mashalkar, A. S.; Parvekar, R. P.
2011-08-01
The work hardening during the forming process is generally ignored in crash analysis. This paper presents computational details of the effect of forming process on crash response of typical Sports Utility Vehicles (SUV). Forming results for front panels of a medium-sized SUV were calculated using Hyperform and LS Dyna. These were imported into the crash model and crash results compared with and without the forming effects. Time taken to generate the forming data by a variety of methods is quantified and the trade-off between time taken and accuracy is examined. LS-DYNA was used for both forming and crash simulations. The effect of thickness, work hardening and residual stresses on the crashworthiness results is measured; crash response is seen to be significantly affected when the effects of forming are included. The paper proposes a systematic method to transfer data from the forming analysis to crashworthiness analysis (both using LS-DYNA), allowing thickness, residual stress and plastic strain data selectively or in combination to be used to initialise the crash model. The relative effect of each of these forming parameters has been examined and the importance of, work hardening on the crash response of the stamping front rail has been identified. A significant change in energy absorption, peak force and stroke of the front rail was predicted, indicating a far stiffer response in the formed rail than would be expected based on the nominal material properties. Therefore, forming effects should be accounted for in vehicle crashworthiness predictions.
Constitutive modeling of aluminum foam and finite element implementation for crash simulations
NASA Astrophysics Data System (ADS)
Bi, Jing
In the past decades metallic foams have been increasingly used as filler materials in crashworthiness applications due to their relatively low cost and high capacity of energy absorption. Due to the destructive nature of crashes, studies on the performance of metallic foams using physical testing have been limited to examining the crushing force histories and/or folding patterns that are insufficient for crashworthiness designs. For this reason, numerical simulations, particularly nonlinear finite element (FE) analyses, play an important role in designing crashworthy foam-filled structures. An effective and numerically stable model is needed for modeling metallic foams that are porous and encounter large nonlinear deformations in crashes. In this study a new constitutive model for metallic foams is developed to overcome the deficiency of existing models in commercial FE codes such as LS-DYNA. The new constitutive model accounts for volume changes under hydrostatic compression and combines the hydrostatic pressure and von Mises stress into one yield function. The change of the compressibility of the metallic foam is handled in the constitutive model by allowing for shape changes of the yield surface in the hydrostatic pressure-von Mises stress space. The backward Euler method is adopted to integrate the constitutive equations to achieve numerical accuracy and stability. The new foam model is verified and validated by existing experimental data before used in FE simulations of crushing of foam-filled columns that have square and hexagonal cross-sections.
Railway vehicle body structures
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1985-01-01
The strength and durability of railway vehicle structures is a major topic of engineering research and design. To reflect this importance the Railway Division of the Institution of Mechanical Engineers organised a conference to discuss all matters relating to railway vehicle design. This book presents the papers discussed in that conference. The contents include: Vehicle body design and the UIC's international contribution; LUL prototype 1986 stock - body structure; vehicle structure for the intermediate capacity transmit system vehicles; car body technology of advanced light rapid transit vehicles; concepts, techniques and experience in the idealization of car body structures for finitemore » element analysis; Calcutta metropolitan railway; design for a lightweight diesel multiple unit body; the design of lightweight inter-city coal structures; the BREL international coach body shell structure; new concepts and design techniques versus material standards; structures of BR diesel electric freight locomotives; structural design philosophy for electric locomotives; suspension design for a locomotive with low structural frequencies; freight wagon structures; a finite element study of coal bodyside panels including the effects of joint flexibility; a fresh approach to the problem of car body design strength; energy absorption in automatic couplings and draw gear; passenger vehicle design loads and structural crashworthiness; design of the front part of railway vehicles (in case of frontal impact); the development of a theoretical technique for rail vehicle structural crashworthiness.« less
49 CFR 229.206 - Design requirements.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Design requirements. 229.206 Section 229.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
Automotive applications of superconductors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ginsberg, M.
1987-01-01
These proceedings compile papers on supercomputers in the automobile industry. Titles include: An automotive engineer's guide to the effective use of scalar, vector, and parallel computers; fluid mechanics, finite elements, and supercomputers; and Automotive crashworthiness performance on a supercomputer.
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.
49 CFR 229.206 - Design requirements.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Design requirements. 229.206 Section 229.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
49 CFR 229.206 - Design requirements.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Design requirements. 229.206 Section 229.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
Fuel tank integrity research : fuel tank analyses and test plans
DOT National Transportation Integrated Search
2013-04-15
The Federal Railroad Administrations Office of Research : and Development is conducting research into fuel tank : crashworthiness. Fuel tank research is being performed to : determine strategies for increasing the fuel tank impact : resistance to ...
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...
U.S. rail equipment crashworthiness standards
DOT National Transportation Integrated Search
2001-05-01
This paper was presented at the conference, "What Can We Realistically Expect from Crash Worthiness? Improving Train Design to Withstand Future Accidents," which was held at the Institute of Mechanical Engineers' Headquarters at London, England on Ma...
VECVEV : Vehicle Crash Virtual Environment Visualizer
DOT National Transportation Integrated Search
2001-03-01
Crashworthiness of automotive vehicles and impact response of highway structures represent very active research areas. The ultimate goal is to design vehicles and highway structures to minimize risk to passengers while also controlling damage to vehi...
Locomotive crashworthiness research : modeling, simulation, and validation
DOT National Transportation Integrated Search
2001-07-01
A technique was developed to realistically simulate the dynamic, nonlinear structural behavior of moving rail vehicles and objects struck during a collision. A new approach considered the interdependence of the many vehicles connected in typical rail...
Serious injury prediction algorithm based on large-scale data and under-triage control.
Nishimoto, Tetsuya; Mukaigawa, Kosuke; Tominaga, Shigeru; Lubbe, Nils; Kiuchi, Toru; Motomura, Tomokazu; Matsumoto, Hisashi
2017-01-01
The present study was undertaken to construct an algorithm for an advanced automatic collision notification system based on national traffic accident data compiled by Japanese police. While US research into the development of a serious-injury prediction algorithm is based on a logistic regression algorithm using the National Automotive Sampling System/Crashworthiness Data System, the present injury prediction algorithm was based on comprehensive police data covering all accidents that occurred across Japan. The particular focus of this research is to improve the rescue of injured vehicle occupants in traffic accidents, and the present algorithm assumes the use of an onboard event data recorder data from which risk factors such as pseudo delta-V, vehicle impact location, seatbelt wearing or non-wearing, involvement in a single impact or multiple impact crash and the occupant's age can be derived. As a result, a simple and handy algorithm suited for onboard vehicle installation was constructed from a sample of half of the available police data. The other half of the police data was applied to the validation testing of this new algorithm using receiver operating characteristic analysis. An additional validation was conducted using in-depth investigation of accident injuries in collaboration with prospective host emergency care institutes. The validated algorithm, named the TOYOTA-Nihon University algorithm, proved to be as useful as the US URGENCY and other existing algorithms. Furthermore, an under-triage control analysis found that the present algorithm could achieve an under-triage rate of less than 10% by setting a threshold of 8.3%. Copyright © 2016 Elsevier Ltd. All rights reserved.
Epidemiology of moderate-to-severe injury patterns observed in rollover crashes.
McMurry, Timothy L; Bose, Dipan; Ridella, Stephen A; Eigen, Ana M; Crandall, Jeff R; Kerrigan, Jason R
2016-05-01
Previous epidemiological studies have highlighted the high risk of injury to the head, thorax, and cervical spine in rollover crashes. However, such results provide limited information on whole-body injury distribution and multiple region injury patterns necessary for the improvement and prioritization of rollover-focused injury countermeasures. Sampled cases representing approximately 133,000 U.S. adult occupants involved in rollover crashes (between 1995 and 2013) sustaining moderate-to-severe injuries were selected from the National Automotive Sampling System Crashworthiness Data System database. A retrospective cohort study, based on a survey of population-based data, was used to identify relevant whole body injury patterns. Among belted occupants injured in rollover crashes, 79.2% sustained injuries to only one body region. The three most frequently injured (AIS2+) body regions were head (42.1%), upper extremity (28.0%), and thorax (27.1%). The most frequent multi-region injury pattern involved the head and upper extremity, but this pattern only accounted for 2.3% of all of occupants with moderate or worse injuries. The results indicated that for rollover-dominated crashes, the frequently observed injury patterns involved isolated body regions. In contrast, multi-region injury patterns are more frequently observed in rollovers with significant planar impacts. Identification of region-specific injury patterns in pure rollover crashes is essential for clarifying injury mitigation targets and developing whole-body injury metrics specifically applicable to rollovers. Copyright © 2016 Elsevier Ltd. All rights reserved.
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...
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...
Crashworthiness studies of locomotive wide nose short hood designs
DOT National Transportation Integrated Search
1999-11-01
This paper investigates the parameters that influence the structural response of typical wide nose locomotive short hoods involved in offset collisions. This accident scenario was chosen based upon the railway collision that occurred in Selma, North ...
Crashworthiness testing of a portable maintenance work-zone barrier.
DOT National Transportation Integrated Search
2008-12-01
Barrier and shadow vehicles generally provide Caltrans maintenance workers protection from errant vehicles entering the work zones, from the upstream direction of traffic flow. This type of protection does not protect workers from vehicles entering t...
Crash survival analysis of 16 agricultural aircraft accidents.
DOT National Transportation Integrated Search
1972-04-01
The study presents pertinent findings from on-the-scene investigations to evaluate the crashworthiness of the present fleet of agricultural applicator aircraft. A detailed presentation of 16 crashes illustrates the fact that most of these specialized...
49 CFR 229.213 - Locomotive manufacturing information.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Locomotive manufacturing information. 229.213 Section 229.213 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
49 CFR 229.213 - Locomotive manufacturing information.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Locomotive manufacturing information. 229.213 Section 229.213 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
49 CFR 229.213 - Locomotive manufacturing information.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Locomotive manufacturing information. 229.213 Section 229.213 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
49 CFR 229.213 - Locomotive manufacturing information.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Locomotive manufacturing information. 229.213 Section 229.213 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
49 CFR 229.213 - Locomotive manufacturing information.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Locomotive manufacturing information. 229.213 Section 229.213 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
Locomotive crashworthiness research : locomotive crew egress evaluation
DOT National Transportation Integrated Search
2002-05-01
The objectives of this study include the identification of aspects of locomotive design and operation related to crew egress or access by rescuers in accidents, with the goal of improving crew survivability. This work identifies the considerations an...
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...
Update on ongoing tank car crashworthiness research : predicted performance and fabrication approach
DOT National Transportation Integrated Search
2008-04-22
Research is currently underway to develop strategies for maintaining the structural integrity of railroad tank cars carrying hazardous materials during collisions. This research, sponsored by the Federal Railroad Administration (FRA), has focused on ...
49 CFR 229.206 - Design requirements.
Code of Federal Regulations, 2010 CFR
2010-10-01
...-climber, emergency egress, emergency interior lighting, and interior configuration design requirements set... 49 Transportation 4 2010-10-01 2010-10-01 false Design requirements. 229.206 Section 229.206..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design...
Rail Safety/Equipment Crashworthiness : Volume 3. Proposed Engineering Standards.
DOT National Transportation Integrated Search
1978-07-01
The document, the third of four volumes, contains recommended Engineering Standards prepared in the format of the standards published in the Code of Federal Regulations (Title 49, Transportation, Parts 200). The standards proposed provide improved oc...
Crashworthiness keeps getting better
DOT National Transportation Integrated Search
2001-03-20
The Insurance Institute for Highway Safety compares results from its 40 mph frontal offset crash tests five years apart. Twice as many vehicles rated "good" overall ratings for 1999-2001 model years as for 1995-1998. Specifies some models that improv...
Full-Scale Dynamic Testing of Locomotive Crashworthy Components.
DOT National Transportation Integrated Search
2015-10-01
The Office of Research, Development, and Technology of the Federal Railroad Administration (FRA) and the Volpe Center are evaluating new occupant protection technologies to increase the safety of passengers and operators in rail equipment. In view of...
Rail Safety/Equipment Crashworthiness : Volume 4. Executive Summary.
DOT National Transportation Integrated Search
1978-07-01
The document, the fourth of four volumes, summarizes the activities and documentation conducted under this contract. The analysis of the accident data highlighted areas where improvements could be made to improve the occupant protection of passenger ...
Design of a workstation table with improved crashworthiness performance
DOT National Transportation Integrated Search
2005-11-05
Work is currently underway to develop strategies to protect rail passengers seated at workstation tables during a collision or derailment. Investigations have shown that during a collision, these tables can present a hostile secondary impact environm...
Collision Scenarios for Assessing Crashworthiness of Passenger Rail Equipment
DOT National Transportation Integrated Search
2010-10-12
In June 2009, at the request of the Federal Railroad Administration (FRA), the Railroad Safety Advisory Committee established the Engineering Task Force (ETF). The ETF is comprised of government, railroads, suppliers, and labor organizations and thei...
Preliminary development of locomotive crashworthy components
DOT National Transportation Integrated Search
2011-03-16
The Federal Railroad Administration (FRA) and the Volpe Center are continuing to evaluate new technologies for increasing the safety of passengers and operators in rail equipment. In recognition of the importance of override prevention in train-to-tr...
Computer simulations and experimental study on crash box of automobile in low speed collision
NASA Astrophysics Data System (ADS)
Liu, Yanjie; Ding, Lin; Yan, Shengyuan; Yang, Yongsheng
2008-11-01
Based on the problems of energy-absorbing components in the automobile low speed collision process, according to crash box frontal crash test in low speed as the example, the simulation analysis of crash box impact process was carried out by Hyper Mesh and LS-DYNA. Each parameter on the influence modeling was analyzed by mathematics analytical solution and test comparison, which guaranteed that the model was accurate. Combination of experiment and simulation result had determined the weakness part of crash box structure crashworthiness aspect, and improvement method of crash box crashworthiness was discussed. Through numerical simulation of the impact process of automobile crash box, the obtained analysis result was used to optimize the design of crash box. It was helpful to improve the vehicles structure and decrease the collision accident loss at most. And it was also provided a useful method for the further research on the automobile collision.
Crashworthiness simulations with DYNA3D
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schauer, D.A.; Hoover, C.G.; Kay, G.J.
1996-04-01
Current progress in parallel algorithm research and applications in vehicle crash simulation is described for the explicit, finite element algorithms in DYNA3D. Problem partitioning methods and parallel algorithms for contact at material interfaces are the two challenging algorithm research problems that are addressed. Two prototype parallel contact algorithms have been developed for treating the cases of local and arbitrary contact. Demonstration problems for local contact are crashworthiness simulations with 222 locally defined contact surfaces and a vehicle/barrier collision modeled with arbitrary contact. A simulation of crash tests conducted for a vehicle impacting a U-channel small sign post embedded in soilmore » has been run on both the serial and parallel versions of DYNA3D. A significant reduction in computational time has been observed when running these problems on the parallel version. However, to achieve maximum efficiency, complex problems must be appropriately partitioned, especially when contact dominates the computation.« less
Blood and Oil: Vehicle Characteristics in Relation to Fatality Risk and Fuel Economy
Robertson, Leon S.
2006-01-01
I examined the potential for a lower risk of death compatible with increased fuel economy among 67 models of 1999–2002 model year cars, vans, and sport-utility vehicles (SUVs) during the calendar years 2000 to 2004. The odds of death for drivers and all persons killed in vehicle collisions were related to vehicle weight, size, stability, and crashworthiness. I calculated that fatality rates would have been 28% lower and fuel use would have been reduced by 16% if vehicle weights had been reduced to the weight of vehicles with the lowest weight per size, where size is measured by the lateral distance needed to perform a 180-degree turn. If, in addition, all vehicles had crashworthiness and stability equal to those of the top-rated vehicles, more than half the deaths involving passenger cars, vans, and SUVs could have been prevented by vehicle modifications. PMID:17018814
Improving the crashworthiness of general aviation aircraft by crash injury investigations.
Kirkham, W R
1982-04-01
An aircraft accident investigation program correlates injuries to occupants with the severity of impacts and structural changes in the crash. Findings brought to the attention of aircraft manufacturers have led to specific aircraft being made more crash-worthy. The finding of a failure in a shoulder harness attachment led to the strengthening of the attachment brace. The way a shoulder harness was joined to a lapbelt was modified following a noted failure. The finding of fractures of lapbelt and shoulder harness cable tiedowns led to the use of stronger cables and modification of the installation. Other findings resulted in a shoulder strap guide being placed on an inertia reel and a side-mounted seat being modified. Described also are three seat-related features which, although meeting FAA standards, during the dynamics of a crash may lack desirable energy attenuation. These findings illustrate the value of aircraft crash injury correlations.
Structures technology for a new generation of rotorcraft
NASA Technical Reports Server (NTRS)
Bartlett, Felton D., Jr.
1989-01-01
This paper presents an overview of structures research at the U. S. Army Aerostructures Directorate. The objectives of this research are to investigate, explore, and demonstrate emerging technologies that will provide lighter, safer, more survivable, and more cost-effective structures for rotorcraft in the 1990s and beyond. The emphasis of today's R&D is to contribute proven structures technology to the U. S. rotorcraft industry and Army aviation that directly impacts tomorrow's fleet readiness and mission capabilities. The primary contributor toward meeting these challenges is the development of high-strength and durable composites to minimize structural weight while maximizing cost effectiveness. Special aviation issues such as delamination of dynamic components, impact damage to thin skins, crashworthiness, and affordable manufacturing need to be resolved before the full potential of composites technology can be realized. To that end, this paper highlights research into composites structural integrity, crashworthiness, and materials applications which addresses these issues.
Stein, Deborah M; Kufera, Joseph A; Ho, Shiu M; Ryb, Gabriel E; Dischinger, Patricia C; O'Connor, James V; Scalea, Thomas M
2011-02-01
Motor vehicle collisions (MVCs) are the leading cause of spine and spinal cord injuries in the United States. Traumatic cervical spine injuries (CSIs) result in significant morbidity and mortality. This study was designed to evaluate both the epidemiologic and biomechanical risk factors associated with CSI in MVCs by using a population-based database and to describe occupant and crashes characteristics for a subset of severe crashes in which a CSI was sustained as represented by the Crash Injury Research Engineering Network (CIREN) database. Prospectively collected CIREN data from the eight centers were used to identify all case occupants between 1996 and November 2009. Case occupants older than 14 years and case vehicles of the four most common vehicle types were included. The National Automotive Sampling System's Crashworthiness Data System, a probability sample of all police-reported MVCs in the United States, was queried using the same inclusion criteria between 1997 and 2008. Cervical spinal cord and spinal column injuries were identified using Abbreviated Injury Scale (AIS) score codes. Data were abstracted on all case occupants, biomechanical crash characteristics, and injuries sustained. Univariate analysis was performed using a χ analysis. Logistic regression was used to identify significant risk factors in a multivariate analysis to control for confounding associations. CSIs were identified in 11.5% of CIREN case occupants. Case occupants aged 65 years or older and those occupants involved in rollover crashes were more likely to sustain a CSI. In univariate analysis of the subset of severe crashes represented by CIREN, the use of airbag and seat belt together (reference) were more protective than seat belt alone (odds ratio [OR]=1.73, 95% confidence interval [CI]=1.32-2.27) or the use of neither restraint system (OR=1.45, 95% CI=1.02-2.07). The most frequent injury sources in CIREN crashes were roof and its components (24.8%) and noncontact sources (15.5%). In multivariate analysis, age, rollover impact, and airbag-only restraint systems were associated with an increased odds of CSI. Using the population-based National Automotive Sampling System's Crashworthiness Data System data, 0.35% of occupants sustained a CSI. In univariate analysis, older age was noted to be a significant risk factor for CSI. Airbag-only restraint systems and both rollover and lateral crashes were also identified as risk factors for CSI. In addition, increasing delta v was highly associated with CSIs. In multivariate analysis, similar risk factors were noted. Of all the restraint systems, seat belt use without airbag deployment was found to be the most protective restraint system (OR=0.29, 95% CI=0.16-0.50), whereas airbag-only restraint was associated with the highest risk of CSI (OR=3.54, 95% CI=2.29-5.46). Despite advances in automotive safety, CSIs sustained in MVC continue to occur too often. Older case occupants are at an increased risk of CSI. Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs. Seat belt use is very effective in preventing CSI, whereas airbag deployment may increase the risk of occupants sustaining a CSI. More protection for older occupants is needed and protection in both rollover and lateral crashes should remain a focus of the automotive industry. The design of airbag restraint systems should be evaluated so that they are not causative of serious injury. In addition, engineers should continue to focus on improving automotive design to minimize the risk of spinal injury to occupants in high severity crashes.
Rear-facing versus forward-facing child restraints: an updated assessment.
McMurry, Timothy L; Arbogast, Kristy B; Sherwood, Christopher P; Vaca, Federico; Bull, Marilyn; Crandall, Jeff R; Kent, Richard W
2018-02-01
The National Highway Traffic Safety Administration and the American Academy of Pediatrics recommend children be placed in rear-facing child restraint systems (RFCRS) until at least age 2. These recommendations are based on laboratory biomechanical tests and field data analyses. Due to concerns raised by an independent researcher, we re-evaluated the field evidence in favour of RFCRS using the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) database. Children aged 0 or 1 year old (0-23 months) riding in either rear-facing or forward-facing child restraint systems (FFCRS) were selected from the NASS-CDS database, and injury rates were compared by seat orientation using survey-weighted χ 2 tests. In order to compare with previous work, we analysed NASS-CDS years 1988-2003, and then updated the analyses to include all available data using NASS-CDS years 1988-2015. Years 1988-2015 of NASS-CDS contained 1107 children aged 0 or 1 year old meeting inclusion criteria, with 47 of these children sustaining injuries with Injury Severity Score of at least 9. Both 0-year-old and 1-year-old children in RFCRS had lower rates of injury than children in FFCRS, but the available sample size was too small for reasonable statistical power or to allow meaningful regression controlling for covariates. Non-US field data and laboratory tests support the recommendation that children be kept in RFCRS for as long as possible, but the US NASS-CDS field data are too limited to serve as a strong statistical basis for these recommendations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Results of a diesel multiple unit fuel tank blunt impact test
DOT National Transportation Integrated Search
2017-04-04
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 types of dyn...
Documentation of deformation from passenger rail two-car impact test
DOT National Transportation Integrated Search
2003-11-01
The Volpe Center has been conducting research into rail equipment crashworthiness in support of the Federal Railroad Administrations (FRA) Office of Research and Development. As part of this research, full-scale crash tests of passenger cars have ...
49 CFR 229.141 - Body structure, MU locomotives.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Body structure, MU locomotives. 229.141 Section 229.141 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness...
Vehicle Component Characterization. Volume 2 : Data Appendices.
DOT National Transportation Integrated Search
1987-01-01
This study developed a set of data which could be used in computer crash occupant simulation models to study automobile crashworthiness. The data generated has been used to develop a data base on the National Highway Traffic Safety Administration's V...
Rail passenger equipment crashworthiness testing requirements and implementation
DOT National Transportation Integrated Search
2000-11-01
This paper describes the requirements and the implementation of a series of impact tests of rail passenger equipment. The test : requirements the desired measurements are dictated by the : characteristics of the vehicle, as well as uncertainties in t...
Route 139 rehabilitation: Pulaski Skyway contract 2 : technical brief.
DOT National Transportation Integrated Search
2017-06-01
This study addressed the need for an aesthetically pleasing historic concrete balustrade design alternative for the Pulaski Skyway in Jersey City, Hudson County. In this study, a crashworthy design was developed according to AASHTO Section 13 specifi...
Crashworthiness : an illustrated commentary on occupant survival in general aviation accidents.
DOT National Transportation Integrated Search
1983-04-01
This report is an illustrated commentary on crash survival in general aviation aircraft. Photographs, drawings, and discussion present some basic concepts of crash forces; mechanisms of injury to occupants; and the roles of shoulder harnesses, lapbel...
Crashworthiness requirements for commuter rail passenger seats
DOT National Transportation Integrated Search
2005-11-05
Occupant experiments using instrumented crash test dummies seated in commuter rail seats have been conducted on board full-scale impact tests of rail cars. The tests have been conducted using both conventional cars and cars modified to incorporate cr...
Preliminary finite element analysis of locomotive crashworthy components
DOT National Transportation Integrated Search
2011-09-21
The Office of Research and Development of the Federal Railroad Administration (FRA) and the Volpe Center are continuing to evaluate new technologies for increasing the safety of passengers and operators in rail equipment. In recognition of the import...
Bus Crashworthiness Issues. Highway Special Investigation Report
DOT National Transportation Integrated Search
1999-09-01
School bus and motorcoach travel are two of the safest forms of transportation in the United States. Each year, on average, nine school bus passengers and four motorcoach passengers are fatally injured in bus crashes, according to the National Highwa...
Code of Federal Regulations, 2010 CFR
2010-10-01
... Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design Requirements § 229.217 Fuel..., comply with the requirements of AAR S-5506, “Performance Requirements for Diesel Electric Locomotive Fuel...
Development of crash energy management designs for existing passenger rail vehicles
DOT National Transportation Integrated Search
2004-11-13
As part of the passenger equipment crashworthiness research, : sponsored by the Federal Railroad Administration and supported by : the Volpe Center, passenger coach and cab cars have been tested in inline : collision conditions. The purpose of these ...
Vehicle Component Characterization. Volume 1 : Project Results.
DOT National Transportation Integrated Search
1987-01-01
This study developed a set of data which could be used in computer crash occupant simulation models to study automobile crashworthiness. The data generated has been used to develop a data base on the National Highway Traffic Safety Administration's V...
A Novel Approach for the Characterization of the Rutting Performance of Pavement Foundations
DOT National Transportation Integrated Search
2017-10-01
Various modeling techniques are playing an increasingly important role as a cost effective means of supplementing crashworthiness data for gaining a better understanding of the injury mechanisms associated with automotive crashes. The interaction of ...
Design for Manufacturing for Energy Absorption Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Del Prete, A.; Primo, T.; Papadia, G.
2011-05-04
In the typical scenario of a helicopter crash, impact with the ground is preceded by a substantially vertical drop, with the result that a seated occupant of a helicopter experiences high spinal loads and pelvic deceleration during such crash due to the sudden arresting of vertical downward motion. It has long been recognized that spinal injuries to occupants of helicopters in such crash scenario can be minimized by seat arrangements which limit the deceleration to which the seated occupant is subjected, relative to the helicopter, to a predetermined maximum, by allowing downward movement of the seated occupant relative to themore » helicopter, at the time of impact with the ground, under a restraining force which, over a limited range of such movement, is limited to a predetermined maximum. In practice, significant benefits, in the way of reduced injuries and reduced seriousness of injuries, can be afforded in this way in such crash situations even where the extent of such controlled vertical movement permitted by the crashworthy seat arrangement is quite limited. Important increase of accident safety is reached with the installation of crashworthy shock absorbers on the main landing gear, but this solution is mostly feasible on military helicopters with long fixed landing gear. Seats can then give high contribution to survivability. Commonly, an energy absorber is a constant load device, if one excludes an initial elastic part of the load-stroke curve. On helicopter seats, this behavior is obtained by plastic deformation of a metal component or scraping of material. In the present work the authors have studied three absorption systems, which differ in relation to their shape, their working conditions and their constructive materials. All the combinations have been analyzed for applications in VIP helicopter seats.« less
Design for Manufacturing for Energy Absorption Systems
NASA Astrophysics Data System (ADS)
Del Prete, A.; Primo, T.; Papadia, G.; Manisi, B.
2011-05-01
In the typical scenario of a helicopter crash, impact with the ground is preceded by a substantially vertical drop, with the result that a seated occupant of a helicopter experiences high spinal loads and pelvic deceleration during such crash due to the sudden arresting of vertical downward motion. It has long been recognized that spinal injuries to occupants of helicopters in such crash scenario can be minimized by seat arrangements which limit the deceleration to which the seated occupant is subjected, relative to the helicopter, to a predetermined maximum, by allowing downward movement of the seated occupant relative to the helicopter, at the time of impact with the ground, under a restraining force which, over a limited range of such movement, is limited to a predetermined maximum. In practice, significant benefits, in the way of reduced injuries and reduced seriousness of injuries, can be afforded in this way in such crash situations even where the extent of such controlled vertical movement permitted by the crashworthy seat arrangement is quite limited. Important increase of accident safety is reached with the installation of crashworthy shock absorbers on the main landing gear, but this solution is mostly feasible on military helicopters with long fixed landing gear. Seats can then give high contribution to survivability. Commonly, an energy absorber is a constant load device, if one excludes an initial elastic part of the load-stroke curve. On helicopter seats, this behavior is obtained by plastic deformation of a metal component or scraping of material. In the present work the authors have studied three absorption systems, which differ in relation to their shape, their working conditions and their constructive materials. All the combinations have been analyzed for applications in VIP helicopter seats.
Motor vehicle crash deaths related to police pursuits in the United States.
Rivara, F P; Mack, C D
2004-04-01
To determine the number and characteristics of motor vehicle crash deaths related to police pursuits in the United States. Analysis of the Fatality Analysis Reporting System and the Crashworthiness Data System of the National Highway Traffic Safety Administration for the years 1994-2002. There were 2654 fatal crashes involving 3965 vehicles and 3146 fatalities during the nine year study period. Of these, 1088 were to people not in the fleeing vehicle. These crashes often occurred at high speed, in the night, on local roads. Most of the pursued drivers had prior motor vehicle related convictions. Many deaths related to police pursuits are to innocent victims. Given that most of the pursued drivers had prior convictions, alternative means of detaining them should be explored.
DOT National Transportation Integrated Search
1979-10-01
The first part of the document contains the research activities presented by the Calspan Corporation, Boeing Vertol Company, and Illinois Institute of Technology Research Institute; transit authority experience by Metropolitan Transportation Authorit...
Mechanical properties of tank car steels retired from the fleet
DOT National Transportation Integrated Search
2009-03-03
As a consequence of recent accidents involving the release of hazardous materials (hazmat), the structural integrity and crashworthiness of railroad tank cars have come under scrutiny. Particular attention has been given to the older portion of the f...
Finite element analysis and full-scale testing of locomotive crashworthy components
DOT National Transportation Integrated Search
2013-04-15
The Office of Research and Development of the Federal Railroad Administration (FRA) and the Volpe Center are continuing to evaluate new technologies for increasing the safety of passengers and operators in rail equipment. In recognition of the import...
Passenger car crippling end-load test and analyses
DOT National Transportation Integrated Search
2017-09-01
The Transportation Technology Center, Inc. (TTCI) performed a series of full-scale tests and a finite element analysis (FEA) in a case study that may become a model for manufacturers seeking to use the waiver process of Tier I crashworthiness and occ...
DOT National Transportation Integrated Search
2012-04-17
The Office of Research and Development of the Federal Railroad Administration conducts engineering research to address protection of passengers and crew during train accidents. This research includes accident investigations and dynamic seat testing t...
49 CFR 229.206 - Design requirements.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Design requirements. 229.206 Section 229.206..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design Requirements § 229.206 Design requirements. Each locomotive used in occupied service must meet the minimum anti...
Code of Federal Regulations, 2010 CFR
2010-10-01
... insurance costs for different makes and models of passenger motor vehicles based upon differences in damage susceptibility and crashworthiness, pursuant to section 201(e) of the Motor Vehicle Information and Cost Savings... OF TRANSPORTATION (CONTINUED) INSURANCE COST INFORMATION REGULATION § 582.1 Scope. This part requires...
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...
Crashworthiness analysis of the January 26, 2005 Glendale, California rail collision
DOT National Transportation Integrated Search
2011-03-16
In Glendale, California on January 26, 2005, impact with : an SUV on the track caused a southbound commuter train to : derail, impact a standing freight train, buckle laterally outward, : and rake the side of a northbound commuter train. Significant ...
Development of a crashworthy seat for commuter aircraft.
DOT National Transportation Integrated Search
1990-09-01
A series of dynamic impact tests were conducted using a prototype seat with an energy absorbing mechanism as part of the seat pan. The seat frame was designed to represent a typical commuter aircraft passenger seat. Tests were conducted in an orienta...
NASA Technical Reports Server (NTRS)
Enders, J. H.
1978-01-01
NASA's aviation safety technology program examines specific safety problems associated with atmospheric hazards, crash-fire survival, control of aircraft on runways, human factors, terminal area operations hazards, and accident factors simulation. While aircraft occupants are ultimately affected by any of these hazards, their well-being is immediately impacted by three specific events: unexpected turbulence encounters, fire and its effects, and crash impact. NASA research in the application of laser technology to the problem of clear air turbulence detection, the development of fire resistant materials for aircraft construction, and to the improvement of seats and restraint systems to reduce crash injuries are reviewed.
Development of crashworthy passenger seats for general-aviation aircraft
NASA Technical Reports Server (NTRS)
Reilly, M. J.; Tanner, A. E.
1979-01-01
Two types of energy absorbing passenger seat concepts suitable for installation in light twin-engine fixed wing aircraft were developed. An existing passenger seat for such an aircraft was used to obtain the envelope constraints. Ceiling suspended and floor supported seat concept designs were developed. A restraint system suitable for both concepts was designed. Energy absorbing hardware for both concepts was fabricated and tension and compression tests were conducted to demonstrate the stroking capability and the force deflection characteristics. Crash impact analysis was made and seat loads developed. The basic seat structures were analyzed to determine the adequacy of their strength under impact loading.
Cummings, P
2002-01-01
Objective: Estimates of any protective effect of seat belts could be exaggerated if some crash survivors falsely claimed to police that they were belted in order to avoid a fine. The aim of this study was to determine whether estimates of seat belt effectiveness differed when based on belt use as recorded by the police and belt use determined by trained crash investigators. Design: Matched cohort study. Setting: United States. Subjects: Adult driver-passenger pairs in the same vehicle with at least one death (n=1689) sampled from crashes during 1988–2000; data from the National Accident Sampling System Crashworthiness Data System. Main outcome measure: Risk ratio for death among belted occupants compared with those not belted. Results: Trained investigators determined post-crash seat belt use by vehicle inspections for 92% of the occupants, confidential interviews with survivors for 5%, and medical or autopsy reports for 3%. Using this information, the adjusted risk ratio for belted persons was 0.36 (95% confidence interval 0.29 to 0.46). The risk ratio was also 0.36 using police reported belt use for the same crashes. Conclusions: Estimates of seat belt effects based upon police data were not substantially different from estimates which used data obtained by trained crash investigators who were not police officers. These results were from vehicles in which at least one front seat occupant died; these findings may not apply to estimates which use data from crashes without a death. PMID:12460976
Planar Impacts in Rollover Crashes: Significance, Distribution and Injury Epidemiology
Bose, Dipan; Kerrigan, Jason R.; Foster, Jonathan B.; Crandall, Jeff R.; Tobaru, Shigeo
2011-01-01
While one third of all fatal motor vehicle crashes involve rollover of the vehicle, a substantially large portion of these rollover crashes involve planar impacts (e.g., frontal, side or rear impact) that influence the crash kinematics and subsequently the injury outcome. The objective of the study was to evaluate the distribution of planar impacts in rollover crashes, and in particular, to describe the differences in the underlying crash kinematics, injury severity and the regional distribution of injuries when compared to the rollover-dominated crashes without significant planar impact (i.e., primary rollovers). Sampled cases (n=6,900) from the U.S. National Automotive Sampling System – Crashworthiness Data System, representing approximately 3.3 million belted drivers involved in a rollover crash in years 1998–2008, were analyzed. Single vehicle rollover crashes with significant planar impact (21% of all rollover crashes) were in general more likely to result in occupant fatality and involved higher incidence of moderate to severe injuries compared to single vehicle primary rollovers (p<0.05). A substantial proportion of the planar impact rollovers ended in single quarter turn crashes (30%), mostly resulting from a frontal impact (59%). While chest was the most frequently injured body region among all rollover victims sustaining severe injuries, severe injuries sustained in primary rollovers were more isolated (single body region) in comparison to the ones sustained in rollovers with planar impacts. The results emphasize the higher risk of rollover victims sustaining an injury and the differences in distribution of injuries sustained when a planar impact is associated with the rollover crash. PMID:22105400
Althoff, Seth; Overberger, Ryan; Sochor, Mark; Bose, Dipan; Werner, Joshua
2017-10-01
There are established and validated clinical decision tools for cervical spine clearance. Almost all the rules include spinal tenderness on exam as an indication for imaging. Our goal was to apply GLASS, a previously derived clinical decision tool for cervical spine clearance, to thoracolumbar injuries. GLass intact Assures Safe Spine (GLASS) is a simple, objective method to evaluate those patients involved in motor vehicle collisions and determine which are at low risk for thoracolumbar injuries. We performed a retrospective cohort study using the National Accident Sampling System-Crashworthiness Data System (NASS-CDS) over an 11-year period (1998-2008). Sampled occupant cases selected in this study included patients age 16-60 who were belt-restrained, front- seat occupants involved in a crash with no airbag deployment, and no glass damage prior to the crash. We evaluated 14,191 occupants involved in motor vehicle collisions in this analysis. GLASS had a sensitivity of 94.4% (95% CI [86.3-98.4%]), specificity of 54.1% (95% CI [53.2-54.9%]), and negative predictive value of 99.9% (95% CI [99.8-99.9%]) for thoracic injuries, and a sensitivity of 90.3% (95% CI [82.8-95.2%]), specificity of 54.2% (95% CI [53.3-54.9%]), and negative predictive value of 99.9% (95% CI [99.7-99.9%]) for lumbar injuries. The GLASS rule represents the possibility of a novel, more-objective thoracolumbar spine clearance tool. Prospective evaluation would be required to further evaluate the validity of this clinical decision rule.
Vehicle postmortem and data analysis of a passenger rail car collision test
DOT National Transportation Integrated Search
2002-04-23
There is an ongoing research program in the United States to investigate and improve rail equipment crashworthiness. As part of this effort, a series of full-scale rail vehicle crash tests are being performed to investigate the crash response of exis...
Prioritizing Safety with Seat Belts: The Unanswered Question.
ERIC Educational Resources Information Center
Farrell, Elaine
1987-01-01
Reviews conflicting federal and state developments (including liability lawsuits) involving seat belt installation on school buses. The National Highway Traffic Safety Administration and the National Transportation Safety Board differ on this issue, and several states are considering seat belt legislation or crashworthiness studies. Hints are…
A numerical evaluation of protection strategies for cab car crashworthiness
DOT National Transportation Integrated Search
1999-11-15
The operator and passengers in cab cars are particularly vulnerable to collisions with objects or with other trains because of their proximity to the point of collision. We present one part of a larger study in which we examined several strategies fo...
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, ...
Rail-car impact tests with steel coil: collision dynamics
DOT National Transportation Integrated Search
2003-04-22
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 structure built to p...
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Fuel tank. 229.217 Section 229.217 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design Requirements § 229.217 Fuel tank. (a) External fuel tanks. Locomotives equipped with external fuel tanks shall, at a minimum...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Fuel tank. 229.217 Section 229.217 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design Requirements § 229.217 Fuel tank. (a) External fuel tanks. Locomotives equipped with external fuel tanks shall, at a minimum...
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Fuel tank. 229.217 Section 229.217 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design Requirements § 229.217 Fuel tank. (a) External fuel tanks. Locomotives equipped with external fuel tanks shall, at a minimum...
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Fuel tank. 229.217 Section 229.217 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Crashworthiness Design Requirements § 229.217 Fuel tank. (a) External fuel tanks. Locomotives equipped with external fuel tanks shall, at a minimum...
Development and fabrication of state-of-the-art end structures for Budd M1 cars
DOT National Transportation Integrated Search
2008-09-24
The Volpe Center and the Federal Railroad Administration are engaged in active research aimed at improving rail vehicle crashworthiness. One component of this research is focused on improving the performance of passenger train cab cars during collisi...
Design optimization of the S-frame to improve crashworthiness
NASA Astrophysics Data System (ADS)
Liu, Shu-Tian; Tong, Ze-Qi; Tang, Zhi-Liang; Zhang, Zong-Hua
2014-08-01
In this paper, the S-frames, the front side rail structures of automobile, were investigated for crashworthiness. Various cross-sections including regular polygon, non-convex polygon and multi-cell with inner stiffener sections were investigated in terms of energy absorption of S-frames. It was determined through extensive numerical simulation that a multi-cell S-frame with double vertical internal stiffeners can absorb more energy than the other configurations. Shape optimization was also carried out to improve energy absorption of the S-frame with a rectangular section. The center composite design of experiment and the sequential response surface method (SRSM) were adopted to construct the approximate design sub-problem, which was then solved by the feasible direction method. An innovative double S-frame was obtained from the optimal result. The optimum configuration of the S-frame was crushed numerically and more plastic hinges as well as shear zones were observed during the crush process. The energy absorption efficiency of the structure with the optimal configuration was improved compared to the initial configuration.
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.
Survey of computer programs for prediction of crash response and of its experimental validation
NASA Technical Reports Server (NTRS)
Kamat, M. P.
1976-01-01
The author seeks to critically assess the potentialities of the mathematical and hybrid simulators which predict post-impact response of transportation vehicles. A strict rigorous numerical analysis of a complex phenomenon like crash may leave a lot to be desired with regard to the fidelity of mathematical simulation. Hybrid simulations on the other hand which exploit experimentally observed features of deformations appear to hold a lot of promise. MARC, ANSYS, NONSAP, DYCAST, ACTION, WHAM II and KRASH are among some of the simulators examined for their capabilities with regard to prediction of post impact response of vehicles. A review of these simulators reveals that much more by way of an analysis capability may be desirable than what is currently available. NASA's crashworthiness testing program in conjunction with similar programs of various other agencies, besides generating a large data base, will be equally useful in the validation of new mathematical concepts of nonlinear analysis and in the successful extension of other techniques in crashworthiness.
Fluid-structure interaction analysis of the drop impact test for helicopter fuel tank.
Yang, Xianfeng; Zhang, Zhiqiang; Yang, Jialing; Sun, Yuxin
2016-01-01
The crashworthiness of helicopter fuel tank is vital to the survivability of the passengers and structures. In order to understand and improve the crashworthiness of the soft fuel tank of helicopter during the crash, this paper investigated the dynamic behavior of the nylon woven fabric composite fuel tank striking on the ground. A fluid-structure interaction finite element model of the fuel tank based on the arbitrary Lagrangian-Eulerian method was constructed to elucidate the dynamic failure behavior. The drop impact tests were conducted to validate the accuracy of the numerical simulation. Good agreement was achieved between the experimental and numerical results of the impact force with the ground. The influences of the impact velocity, the impact angle, the thickness of the fuel tank wall and the volume fraction of water on the dynamic responses of the dropped fuel tank were studied. The results indicated that the corner of the fuel tank is the most vulnerable location during the impact with ground.
Improvement of Progressive Damage Model to Predicting Crashworthy Composite Corrugated Plate
NASA Astrophysics Data System (ADS)
Ren, Yiru; Jiang, Hongyong; Ji, Wenyuan; Zhang, Hanyu; Xiang, Jinwu; Yuan, Fuh-Gwo
2018-02-01
To predict the crashworthy composite corrugated plate, different single and stacked shell models are evaluated and compared, and a stacked shell progressive damage model combined with continuum damage mechanics is proposed and investigated. To simulate and predict the failure behavior, both of the intra- and inter- laminar failure behavior are considered. The tiebreak contact method, 1D spot weld element and cohesive element are adopted in stacked shell model, and a surface-based cohesive behavior is used to capture delamination in the proposed model. The impact load and failure behavior of purposed and conventional progressive damage models are demonstrated. Results show that the single shell could simulate the impact load curve without the delamination simulation ability. The general stacked shell model could simulate the interlaminar failure behavior. The improved stacked shell model with continuum damage mechanics and cohesive element not only agree well with the impact load, but also capture the fiber, matrix debonding, and interlaminar failure of composite structure.
Motor vehicle crash deaths related to police pursuits in the United States
Rivara, F; Mack, C
2004-01-01
Objective: To determine the number and characteristics of motor vehicle crash deaths related to police pursuits in the United States. Methods: Analysis of the Fatality Analysis Reporting System and the Crashworthiness Data System of the National Highway Traffic Safety Administration for the years 1994–2002. Results: There were 2654 fatal crashes involving 3965 vehicles and 3146 fatalities during the nine year study period. Of these, 1088 were to people not in the fleeing vehicle. These crashes often occurred at high speed, in the night, on local roads. Most of the pursued drivers had prior motor vehicle related convictions. Conclusions: Many deaths related to police pursuits are to innocent victims. Given that most of the pursued drivers had prior convictions, alternative means of detaining them should be explored. PMID:15066973
Post test review of a single car test of multi-level passenger equipment
DOT National Transportation Integrated Search
2008-04-22
The single car test of multi-level equipment described in : this paper was designed to help evaluate the crashworthiness of : a multi-level car in a controlled collision. The data collected : from this test will be used to refine engineering models. ...
DOT National Transportation Integrated Search
2011-09-01
This report presents the test results and finite element correlations of a full-scale dynamic collision test with rail vehicles as part of the Federal Railroad Administrations research program on improved crashworthiness of locomotive structures. ...
DOT National Transportation Integrated Search
2008-01-31
Crash Energy Management (CEM) is a crashworthiness strategy that : incorporates crush zones into the design of passenger railcars. In the event of a : collision, crush zones are engineered to collapse in a controlled manner and : distribute crush to ...
The 1986 advances in bioengineering
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lantz, S.A.; King, A.I.
1986-01-01
This book presents the papers given at a conference on biomedicine. Topics considered at the conference included a mathematical method for obtaining three-dimensional information from standard two-dimensional radiographs, the human lumbar spine, scoliosis and instrumentation, vehicle crashworthiness, lung mechanics, physiological fluid mechanics, microgravity, cardiovascular mechanics, and soft tissue.
DOT National Transportation Integrated Search
1980-06-01
A specific goal of safety is to reduce the number of injuries that may result from the collision of two trains. In Volume IV, a computer code for the simulated crash of two railcar consists is described. The code is capable of simulating the mechanic...
DOT National Transportation Integrated Search
2000-11-01
In an effort to study occupant survivability in train collisions, analyses and tests were conducted to understand and improve the crashworthiness of rail vehicles. A collision dynamics model was developed in order to estimate the rigid body motion of...
DOT National Transportation Integrated Search
1975-11-01
This publication presents information related to the following: Railcar override; Priority areas for the development of cost effective improved car structures; Preliminary design study of impact energy absorbing device; Cost effectiveness of structur...
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...
Crashworthiness of Small Poststandard School Buses: Safety Study.
ERIC Educational Resources Information Center
National Transportation Safety Board (DOT), Washington, DC.
In 1977, a series of Federal Motor Vehicle Safety Standards (FMVSS) for school buses became effective, mandating different performance standards for school buses compared to other buses. Because data on the crash performance of school buses built to these standards were lacking, the National Transportation Safety Board conducted a series of…
76 FR 7628 - Petition for Waiver of Compliance
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-10
... constructed by European manufacturer and meet European safety standards for crashworthiness and related safety... Engineering Task Force report to the Passenger Safety Working Group of the Railroad Safety Advisory Committee... business hours (9 a.m.-5 p.m.) at the above facility. All documents in the public docket are also available...
Increased Rail Transit Vehicle Crashworthiness in Head-On Collisions. Volume II. Primary Collision.
DOT National Transportation Integrated Search
1980-06-01
A specific goal of safety is to reduce the number of injuries that may result from the collision of two trains. In Volume II, an analytical model in two dimensions, longitudinal and vertical, of the primary collision of two impacting urban railcar co...
Increased Rail Transit Vehicle Crashworthiness in Head-On Collisions. Volume I. Initial Impact.
DOT National Transportation Integrated Search
1980-06-01
A specific goal of safety is to reduce the number of injuries that may result from the collision of two trains. In Volume I, a two-dimensional analytic simulation model of the leading cars of two impacting transit car consists is formulated. This mod...
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-...
75 FR 38172 - Petition for Waiver of Compliance
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-01
... requirements of its safety standards. The individual petition is described below, including the party seeking... European safety standards for crash-worthiness and related safety measures for use on its proposed high... certain requirements of 49 CFR part 238, Passenger Equipment Safety Standards (Sec. Sec. 238.115, 238.121...
The influence of train type, car weight, and train length on passenger train crashworthiness
DOT National Transportation Integrated Search
2005-03-16
Crash energy management (CEM) is a type of equipment : design that is intended to protect occupant space during a : collision. Structures at the front and back of each car act as : crumple zones that absorb the collision energy. CEM is : intended to ...
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 :...
Differential Rollover Risk in Vehicle-to-Traffic Barrier Collisions
Gabauer, Douglas J.; Gabler, Hampton C.
2009-01-01
In the roadside safety community, there has been debate over the influence of vehicle and barrier type on rollover rates in traffic barrier crashes. This study investigated rollover rates between sport utility vehicles (SUVs), pickup trucks, and cars in vehicle-traffic barrier crashes and has examined the effect of barrier type on rollover risk for concrete barrier and metal barrier impacts. The analysis included 955 barrier impact cases that were selected from 11-years of in-depth crash data available through the National Automotive Sampling System (NASS) / Crashworthiness Data System (CDS). In real world tow-away level longitudinal barrier collisions, the most important predictors of vehicle rollover were found to be vehicle type and whether the vehicle was tracking prior to barrier impact. Based on binary logistic regression, SUVs were found to have 8 times the risk of rollover as cars in barrier impacts. Although pickups were found to have an increased risk of rollover compared to cars, the risk was not as pronounced as that found for SUVs. This finding has direct implications for the full scale crash testing of longitudinal barriers as the testing procedures have been predicated on the assumption that the pickup truck provides a critical or worst case impact scenario. In towaway crashes, our study does not support the notion that concrete barriers have a higher risk of vehicle rollover than metal beam barriers. PMID:20184839
Racial Disparities in Survival Among Injured Drivers
Haskins, Amy E.; Clark, David E.; Travis, Lori L.
2013-01-01
Prior studies on racial and ethnic disparities in survival after motor vehicle crashes have examined only population-based death rates or have been restricted to hospitalized patients. In the current study, we examined 3 components of crash survival by race/ethnicity: survival overall, survival to reach a hospital, and survival among those hospitalized. Nine years of data (from 2000 through 2008) from the National Automotive Sampling System Crashworthiness Data System were used to examine white non-Hispanic, black non-Hispanic, and Hispanic drivers aged ≥15 years with serious injuries (injury severity scores of ≥9). By using multivariable logistic regression, we found that a driver's race/ethnicity was not significantly associated with overall survival after being injured in a crash (for blacks, odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.36, 1.32; for Hispanics, OR = 1.00, 95% CI: 0.59, 1.72), and blacks and Hispanics were equally likely to survive to be treated at a hospital compared with whites (for blacks, OR = 1.00, 95% CI: 0.52, 1.93; for Hispanics, OR = 1.13, 95% CI: 0.71, 1.79). However, among patients who were treated at a hospital, blacks were 50% less likely to survive 30 days compared with whites (OR = 0.50, 95% CI: 0.33, 0.76). The disparity in survival after serious traffic injuries among blacks appears to occur after hospitalization, not in prehospital survival. PMID:23371352
Technology of civil usage of composites. [in commercial aircraft structures
NASA Technical Reports Server (NTRS)
Kemp, D. E.
1977-01-01
The paper deals with the use of advanced composites in structural components of commercial aircraft. The need for testing the response of a material system to service environment is discussed along with methods for evaluating design and manufacturing aspects of a built-up structure under environmental conditions and fail-safe (damage-tolerance) evaluation of structures. Crashworthiness aspects, the fire-hazard potential, and electrical damage of composite structures are considered. Practical operational experience with commercial aircraft is reviewed for boron/epoxy foreflaps, Kevlar/epoxy fillets and fairings, graphite/epoxy spoilers, graphite/polysulfone spoilers, graphite/epoxy floor posts, boron/aluminum aft pylon skin panels, graphite/epoxy engine nose cowl outer barrels, and graphite/epoxy upper aft rudder segments.
Active vibration attenuating seat suspension for an armored helicopter crew seat
NASA Astrophysics Data System (ADS)
Sztein, Pablo Javier
An Active Vibration Attenuating Seat Suspension (AVASS) for an MH-60S helicopter crew seat is designed to protect the occupants from harmful whole-body vibration (WBV). Magnetorheological (MR) suspension units are designed, fabricated and installed in a helicopter crew seat. These MR isolators are built to work in series with existing Variable Load Energy Absorbers (VLEAs), have minimal increase in weight, and maintain crashworthiness for the seat system. Refinements are discussed, based on testing, to minimize friction observed in the system. These refinements include the addition of roller bearings to replace friction bearings in the existing seat. Additionally, semi-active control of the MR dampers is achieved using special purpose built custom electronics integrated into the seat system. Experimental testing shows that an MH-60S retrofitted with AVASS provides up to 70.65% more vibration attenuation than the existing seat configuration as well as up to 81.1% reduction in vibration from the floor.
AIAA/SAE/ASCE/ATRIF/TRB international air transportation conference, 1981
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1981-01-01
This collection of 18 papers was presented at the meeting; all of the papers ae indexed separately. Subjects covered include jet fuel availability and price trends, flight planning, airliner maintenance for fuel efficiency, airport research and development needs, airport capacity enhancement, aircraft structural crashworthiness, in-flight collision avoidance, aircraft engines, and others.
Safety Study--Crashworthiness of Large Poststandard Schoolbuses.
ERIC Educational Resources Information Center
National Transportation Safety Board (DOT), Washington, DC.
This study reports on the crash performance of large poststandard school buses (school buses manufactured after April 1, 1977, and weighing more than 10,000 pounds unloaded) in 43 accidents investigated by the National Transportation Safety Board. The report discusses the Safety Board's findings as to how well the standards are working to protect…
Plans for crash-tested wood bridge railings for concrete decks
Michael A. Ritter; Ronald K. Faller; Barry T. Rosson; Paula D. Hilbrich Lee; Sheila Rimal Duwadi
1998-01-01
As part of a continuing cooperative research between the Midwest Roadside Safety Facility (MwRSF); the USDA Forest Service, Forest Products Laboratory (FPL); and the Federal Highway Administration (FHWA), several crashworthy wood bridge railings and approach railing transitions have been adapted for use on concrete bridge decks. These railings meet testing and...
Crashworthy Troop Seat Testing Program
1977-11-01
19 ’rest 4 . . . . . . . . . .. . 29 | Detail Design’Finalization. .... 29 Vertical Wire - Bending Energy Attenuator 32 Toggle Latch...Strut Wire - Bending Attenuator Force Deflection. . . . ................... 28 15 Notched Wire and Pin Anchorage Test Specimen . 30 16 Quick-Disconnect...and Hold-Down Cable ......... 31 17 Failed Hold-Down Cable ...... . . . . 31 18 Wire - Bending Tension/Compression Energy Attenuator
Federal Register 2010, 2011, 2012, 2013, 2014
2013-10-31
.... These features are associated with a hybrid construction that uses both composite and metallic materials... wing consists of resin transfer infusion (RTI) skins with composite spars and metallic ribs. The empennage consists of composite sandwich skins with metallic spars and ribs. The airframe has a sandwich...
NASA Astrophysics Data System (ADS)
Suman, Shwetabh; Shah, Haard; Susarla, Vaibhav; Ravi, K.
2017-11-01
According to the statistics it has been seen that everyday nearly 400 people are killed due to road accidents. Due to this it has become an important concern to concentrate on the safety of the passengers which can be done by improving the crashworthiness of the vehicle. During the impact, a large amount of energy is released which if not absorbed, will be transmitted to the passenger compartment. For the safety of the passenger this energy has to be absorbed. Front rail is one of the main energy absorbing components in the vehicle front structure. When it comes to the structure and material of the part or component of the vehicle that is to be designed for crash, it is done based on three parameters: Specific Energy of Absorption, Mass of the front rail and maximum crush force. In this work, we are considering different internal geometries with different materials to increase the energy absorbing capacity of the front rail. Based on the extensive analysis carried aluminium seizes to be the opt material for frontal crash.
Althoff, Seth; Overberger, Ryan; Sochor, Mark; Bose, Dipan; Werner, Joshua
2017-01-01
Introduction There are established and validated clinical decision tools for cervical spine clearance. Almost all the rules include spinal tenderness on exam as an indication for imaging. Our goal was to apply GLASS, a previously derived clinical decision tool for cervical spine clearance, to thoracolumbar injuries. GLass intact Assures Safe Spine (GLASS) is a simple, objective method to evaluate those patients involved in motor vehicle collisions and determine which are at low risk for thoracolumbar injuries. Methods We performed a retrospective cohort study using the National Accident Sampling System-Crashworthiness Data System (NASS-CDS) over an 11-year period (1998–2008). Sampled occupant cases selected in this study included patients age 16–60 who were belt-restrained, front- seat occupants involved in a crash with no airbag deployment, and no glass damage prior to the crash. Results We evaluated 14,191 occupants involved in motor vehicle collisions in this analysis. GLASS had a sensitivity of 94.4% (95% CI [86.3–98.4%]), specificity of 54.1% (95% CI [53.2–54.9%]), and negative predictive value of 99.9% (95% CI [99.8–99.9%]) for thoracic injuries, and a sensitivity of 90.3% (95% CI [82.8–95.2%]), specificity of 54.2% (95% CI [53.3–54.9%]), and negative predictive value of 99.9% (95% CI [99.7–99.9%]) for lumbar injuries. Conclusion The GLASS rule represents the possibility of a novel, more-objective thoracolumbar spine clearance tool. Prospective evaluation would be required to further evaluate the validity of this clinical decision rule. PMID:29085544
Spinal injury in car crashes: crash factors and the effects of occupant age.
Bilston, Lynne E; Clarke, Elizabeth C; Brown, Julie
2011-08-01
Motor vehicle crashes are the leading cause of serious spinal injury in most developed nations. However, since these injuries are rare, systematic analyses of the crash factors that are predictive of spinal injury have rarely been performed. This study aimed to use a population-reference crash sample to identify crash factors associated with moderate to severe spinal injury, and how these vary with occupant age. The US National Automotive Sampling System Crashworthiness Data System (NASS) data for 1993-2007 were analysed using logistic regression to identify crash factors associated with Abbreviated Injury Scale (AIS)2+ spinal injury among restrained vehicle passengers. Risk of moderate or severe spinal injury (AIS2+) was associated with higher severity crashes (OR=3.5 (95% CI 2.6 to 4.6)), intrusion into an occupant's seating position (OR=2.7 (95% CI 1.9 to 3.7)), striking a fixed object rather than another car (OR=1.7 (95% CI 1.3 to 2.1)), and use of a shoulder-only belt (OR=2.7 (95% CI 1.5 to 4.8)). Older occupants (65 years or older) were at higher risk of spinal injury than younger adults in frontal, side and rollover crashes. Children under 16 were at a lower risk of spinal injury than adults in all crash types except frontal crashes. While the risk of serious spinal injury in motor vehicle crashes is low, these injuries are more common in crashes of higher severity or into fixed objects, and in the presence of intrusion. There are elevated risks of spinal injury for older occupants compared with younger adults, which may reflect changes in biomechanical tolerances with age. Children appear to be at lower risk of serious spinal injury than adults except in frontal crashes.
Front air bag nondeployments in frontal crashes fatal to drivers or right-front passengers.
Braver, Elisa R; McCartt, Anne T; Sherwood, Christopher P; Zuby, David S; Blanar, Laura; Scerbo, Marge
2010-04-01
Public concern has arisen about the reliability of front air bags because Fatality Analysis Reporting System (FARS) data indicate many nondeployed air bags in fatal frontal crashes. However, the accuracy of air bag deployment, the variable in question, is uncertain. This study aimed to provide more certain estimates of nondeployment incidence in fatal frontal crashes. Fatally injured passenger vehicle drivers and right-front passengers in frontal crashes were identified in two U.S. databases for calendar years 1998-2006 and model years 1994-2006: FARS, a census of police-reported fatal crashes on public roads, and National Automotive Sampling System/Crashworthiness Data System (NASS/CDS), a probability sample of tow-away crashes. NASS/CDS contains subsets of fatal crashes in FARS and collects detailed data using crash investigators. Front air bag deployment coding for front-seat occupant fatalities was compared in FARS and NASS/CDS, and case reviews were conducted. Among FARS frontal deaths with available deployment status (N = 43,169), front air bags were coded as not deployed for 18 percent of front occupants. In comparison, NASS/CDS (N = 628) reported 9 percent (weighted estimate) nondeployment among front occupants killed. Among crashes common to both databases, NASS/CDS reported deployments for 45 percent of front occupant deaths for which FARS had coded nondeployments. Detailed case reviews of NASS/CDS crashes indicated highly accurate coding for deployment status. Based on this case review, 8 percent (weighted estimate) of front occupant deaths in frontal crashes appeared to involve air bag nondeployments; 1-2 percent of front occupant deaths represented potential system failures where deployments would have been expected. Air bag deployments appeared unwarranted in most nondeployments based on crash characteristics. FARS data overstate the magnitude of the problem of air bag deployment failures; steps should be taken to improve coding. There are inherent uncertainties in judgments about whether or not air bags would be expected to deploy in some crashes. Continued monitoring of air bag performance is warranted.
Crush testing, characterizing, and modeling the crashworthiness of composite laminates
NASA Astrophysics Data System (ADS)
Garner, David Michael, Jr.
Research in the field of crashworthiness of composite materials is presented. A new crush test method was produced to characterize the crush behavior of composite laminates. In addition, a model of the crush behavior and a method for rank ordering the energy absorption capability of various laminates were developed. The new crush test method was used for evaluating the crush behavior of flat carbon/epoxy composite specimens at quasi-static and dynamic rates. The University of Utah crush test fixture was designed to support the flat specimen against catastrophic buckling. A gap, where the specimen is unsupported, allowed unhindered crushing of the specimen. In addition, the specimen's failure modes could be clearly observed during crush testing. Extensive crush testing was conducted wherein the crush force and displacement data were collected to calculate the energy absorption, and high speed video was captured during dynamic testing. Crush tests were also performed over a range of fixture gap heights. The basic failure modes were buckling, crack growth, and fracture. Gap height variations resulted in poorly, properly, and overly constrained specimens. In addition, guidelines for designing a composite laminate for crashworthiness were developed. Modeling of the crush behavior consisted of the delamination and fracture of a single ply or group of like plies during crushing. Delamination crack extension was modeled using the mode I energy release rate, G lc, where an elastica approach was used to obtain the strain energy. Variations in Glc were briefly explored with double cantilever beam tests wherein crack extension occurred along a multidirectional ply interface. The model correctly predicted the failure modes for most of the test cases, and offered insight into how the input parameters affect the model. The ranking method related coefficients of the laminate and sublaminate stiffness matrices, the ply locations within the laminate, and the laminate thickness. The ranking method correctly ordered the laminates tested in this study with respect to their energy absorption.
Personal Aircraft Point to the Future of Transportation
NASA Technical Reports Server (NTRS)
2010-01-01
NASA's Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) programs, as well as a number of Agency innovations, have helped Duluth, Minnesota-based Cirrus Design Corporation become one of the world's leading manufacturers of general aviation aircraft. SBIRs with Langley Research Center provided the company with cost-effective composite airframe manufacturing methods, while crashworthiness testing at the Center increased the safety of its airplanes. Other NASA-derived technologies on Cirrus SR20 and SR22 aircraft include synthetic vision systems that help pilots navigate and full-plane parachutes that have saved the lives of more than 30 Cirrus pilots and passengers to date. Today, the SR22 is the world's top-selling Federal Aviation Administration (FAA)-certified single-engine airplane.
Effects Of Rapid Crushing On Composites
NASA Technical Reports Server (NTRS)
Farley, Gary L.
1990-01-01
Experimental study described in NASA technical memorandum performed to determine whether crash energy-absorption capabilities of graphite/epoxy and Kevlar/epoxy composite materials are functions of speed of crushing. Additional objective to develop understanding of mechanisms of crushing. Technology applied to enhancement of safety and crashworthiness of automobiles, design of energy-absorbing devices in machinery, and problems involving explosions and impacts.
Weaver, Ashley A.; Barnard, Ryan T.; Kilgo, Patrick D.; Martin, R. Shayn; Stitzel, Joel D.
2013-01-01
The study purpose was to develop mortality-based metrics of injury severity for frequent motor vehicle crash (MVC) injuries. Injury severity was quantified with mortality-based metrics for 240 injuries comprising the top 95% most frequently occurring AIS 2+ injuries in the National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) 2000–2011. Mortality risk ratios (MRRs) were computed by dividing the number of deaths by occurrences for each of the 240 injuries using National Trauma Data Bank Research Data System (NTDB-RDS) MVC cases. MRRMAIS was computed using only patients with a maximum AIS (MAIS) equal to the AIS severity of a given injury. Each injury had an associated MRR and MRRMAIS which ranged from zero (0% mortality representing low severity) to one (100% or universal mortality representing high severity). Injuries with higher MRR and MRRMAIS values are considered more severe because they resulted in a greater proportion of deaths among injured patients. The results illustrated an overall positive trend between AIS severity and the MRR and MRRMAIS values as expected, but showed large variations in MRR and MRRMAIS for some injuries of the same AIS severity. Mortality differences up to 83% (MRR) and 54% (MRRMAIS) were observed for injuries of the same AIS severity. The MRR-based measures of injury severity indicate that some lower AIS severity injuries may result in as many deaths as higher AIS severity injuries. This data-driven determination of injury severity using MRR and MRRMAIS provides a supplement or an alternative to AIS severity classification. PMID:24406961
Weaver, Ashley A; Barnard, Ryan T; Kilgo, Patrick D; Martin, R Shayn; Stitzel, Joel D
The study purpose was to develop mortality-based metrics of injury severity for frequent motor vehicle crash (MVC) injuries. Injury severity was quantified with mortality-based metrics for 240 injuries comprising the top 95% most frequently occurring AIS 2+ injuries in the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) 2000-2011. Mortality risk ratios (MRRs) were computed by dividing the number of deaths by occurrences for each of the 240 injuries using National Trauma Data Bank Research Data System (NTDB-RDS) MVC cases. MRRMAIS was computed using only patients with a maximum AIS (MAIS) equal to the AIS severity of a given injury. Each injury had an associated MRR and MRRMAIS which ranged from zero (0% mortality representing low severity) to one (100% or universal mortality representing high severity). Injuries with higher MRR and MRRMAIS values are considered more severe because they resulted in a greater proportion of deaths among injured patients. The results illustrated an overall positive trend between AIS severity and the MRR and MRRMAIS values as expected, but showed large variations in MRR and MRRMAIS for some injuries of the same AIS severity. Mortality differences up to 83% (MRR) and 54% (MRRMAIS) were observed for injuries of the same AIS severity. The MRR-based measures of injury severity indicate that some lower AIS severity injuries may result in as many deaths as higher AIS severity injuries. This data-driven determination of injury severity using MRR and MRRMAIS provides a supplement or an alternative to AIS severity classification.
Kim, Taewung; Bose, Dipan; Foster, Jon; Bollapragada, Varun; Crandall, Jeff R; Clauser, Mark; Kerrigan, Jason R
2017-10-01
This study aimed to identify common patterns of pre-ballistic vehicle kinematics and roadway characteristics of real-world rollover crashes. Rollover crashes that were enrolled in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) between the years 2000 and 2010 were analyzed. A descriptive analysis was performed to understand the characteristics of the pre-ballistic phase. Also, a frequency based pattern analysis was performed using a selection of NASS-CDS variables describing the pre-ballistic vehicle kinematics and roadway characteristics to rank common pathways of rollover crashes. Most case vehicles departed the road due to a loss of control/traction (LOC) (61%). The road departure with LOC was found to be 13.4 times more likely to occur with slippery road conditions compared to dry conditions. The vehicle was typically laterally skidding with yawing prior to a rollover (66%). Most case vehicles tripped over (82%) mostly at roadside/median (69%). The tripping force was applied to the wheels/tires (82%) from the ground (79%). The combination of these six most frequent attributes resulted in the most common scenario, which accounted for 26% of the entire cases. Large proportion of road departure with LOC (61%) implies electronic stability control (ESC) systems being an effective countermeasure for preventing single-vehicle rollover crashes. Furthermore, the correlation between the road departure with LOC and the reduced friction limit suggests the necessity of the performance evaluation of ESC under compromised road surface condition. Copyright © 2017 Elsevier Ltd. All rights reserved.
Antona-Makoshi, Jacobo; Mikami, Koji; Lindkvist, Mats; Davidsson, Johan; Schick, Sylvia
2018-08-01
This study estimated the frequency and risk of Moderate-to-Maximal traumatic brain injuries sustained by occupants in motor vehicle crashes in the US. National Automotive Sampling System - Crashworthiness Data System crashes that occurred in years 2001-2015 with light vehicles produced 2001 or later were incorporated in the study. Crash type, crash severity, car model year, belt usage and occupant age and sex were controlled for in the analysis. The results showed that Moderate concussions account for 79% of all MAIS brain 2+ injuries. Belted occupants were at lower risks than unbelted occupants for most brain injury categories, including concussions. After controlling for the effects of age and crash severity, belted female occupants involved in frontal crashes were estimated to be 1.5 times more likely to sustain a concussion than male occupants in similar conditions. Belted elderly occupants were found to be at 10.5 and 8 times higher risks for sub-dural haemorrhages than non-elderly belted occupants in frontal and side crashes, respectively. Adopted occupant protection strategies appear to be insufficient to achieve significant decreases in risk of both life-threatening brain injuries and concussions for all car occupants. Further effort to develop occupant and injury specific strategies for the prevention of brain injuries are needed. This study suggests that these strategies may consider prioritization of life-threatening brain vasculature injuries, particularly in elderly occupants, and concussion injuries, particularly in female occupants. Copyright © 2018 Elsevier Ltd. All rights reserved.
Bennett, Tellen D; Kaufman, Robert; Schiff, Melissa; Mock, Charles; Quan, Linda
2006-09-01
The mechanism, crash characteristics, and spectrum of lower extremity injuries in children restrained in forward-facing car seats during front and rear impacts have not been described. We identified in two databases children who sustained lower extremity injuries while restrained in forward-facing car seats. To identify the mechanism, we analyzed crash reconstructions from three frontal-impact cases from the Crash Injury Research and Engineering Network. To further describe the crash and injury characteristics we evaluated children between 1 and 4 years of age with lower extremity injuries from front or rear impacts in the National Automotive Sampling System (NASS) Crashworthiness Data System (CDS) database. Crash reconstruction data demonstrated that the likely mechanism of lower extremity injury was contact between the legs and the front seatbacks. In the CDS database, we identified 15 children with lower extremity injuries in a forward-facing child seat, usually (13 out of 15) placed in the rear seat, incurred in frontal impacts (11 out of 15). Several (5 out of 15) children were in unbelted or improperly secured forward-facing car seats. Injury Severity Scores varied widely (5-50). Children in forward-facing car seats involved in severe front or rear crashes may incur a range of lower extremity injury from impact with the car interior component in front of them. Crash scene photography can provide useful information about anatomic sites at risk for injury and alert emergency department providers to possible subtle injury.
Predicting patients that require care at a trauma center: analysis of injuries and other factors.
Schoell, Samantha L; Doud, Andrea N; Weaver, Ashley A; Barnard, Ryan T; Meredith, J Wayne; Stitzel, Joel D; Martin, R Shayn
2015-04-01
The detection of occult or unpredictable injuries in motor vehicle crashes (MVCs) is crucial in correctly triaging patients and thus reducing fatalities. The purpose of the study was to develop a metric that indicates the likelihood that an injury sustained in a MVC would require management at a Level I/II trauma centre (TC) versus a non-trauma centre (non-TC). Transfer Scores (TSs) were computed for 240 injuries that comprise the top 95% most frequently occurring injuries in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) with an Abbreviated Injury Scale (AIS) severity of 2 or greater. A TS for each injury was computed using the proportions of patients involved in a MVC from the National Inpatient Sample (NIS) that were transferred to a TC or managed at a non-TC. Similarly, a TSMAIS that excludes patients with higher severity co-injuries was calculated using the proportion of patients with a maximum AIS (MAIS) equal to the AIS severity of a given injury. The results indicated for injuries of a given AIS severity, body region, and injury type, there were large variations in the TSMAIS. Overall results demonstrated higher TSMAIS values when injuries were internal, haemorrhagic, intracranial or of moderate severity (AIS 3-5). Specifically, injuries to the head possessed a TSMAIS that ranged from 0.000 to 0.889, with head injuries of AIS 3-5 severities being the most likely to be transferred. The analysis indicated that the TSMAIS is not solely correlated with AIS severity and therefore it captures other important aspects of injury such as predictability and trauma system capabilities. The TS and TSMAIS can be useful in advanced automatic crash notification (AACN) research for the detection of highly unpredictable injuries in MVCs that require direct transport to a TC. Copyright © 2014 Elsevier Ltd. All rights reserved.
Review of Aircraft Crash Structural Response Research.
1982-08-01
structures consisting of conventional built-up metallic construction and those consisting of advanced composite materials were of interest. The latter...increasing importance. Some recent theoretical and experimental studies of the behavior of composite - material structures subjected to severe static...dynamic, and/or impact conditions are noted. Such topics as crashworthiness testing ot composite fuselage structures, the impact resistance of graphite and
A Review of Crashworthiness of Composite Aircraft Structures
1990-02-01
proprietary, or other reaons . Details on the availability of these publications may be obtained from: Graphics Section, National Research Council Canada...bottoming out, good energy-absorbing and load-limiting ability, good post-crushing structural integrity and no significant load rate sensitivity. In a... good energy absorption capability under compressive loadings. However, under tensile or bending conditions, structural integrity may be lost at initial
NASA Astrophysics Data System (ADS)
D'Amours, Guillaume; Rahem, Ahmed; Williams, Bruce; Worswick, Michael; Mayer, Robert
2007-05-01
The automotive industry, with an increasing demand to reduce vehicle weight through the adoption of lightweight materials, requires a search of efficient methods that suit these materials. One attractive concept is to use hydroforming of aluminium tubes. By using FE simulations, the process can be optimized to reduce the risk for failure while maintaining energy absorption and component integrity under crash conditions. It is important to capture the level of residual ductility after forming to allow proper design for crashworthiness. This paper presents numerical and experimental studies that have been carried out for high pressure hydroforming operations to study the influence of the tube corner radius, end feeding, material thinning, and work hardening in 76.2 mm diameter, 3 mm wall thickness AA5754 aluminium alloy tube. End feeding was used to increase the formability of the tubes. The influence of the end feed displacement versus tube forming pressure schedule was studied to optimize the forming process operation to reduce thinning. Validation of the numerical simulations was performed by comparison of the predicted strain distributions and thinning, with measured quantities. The effect of element formulation (thin shell versus solid elements) was also considered in the models.
Crashworthiness analysis using advanced material models in DYNA3D
DOE Office of Scientific and Technical Information (OSTI.GOV)
Logan, R.W.; Burger, M.J.; McMichael, L.D.
1993-10-22
As part of an electric vehicle consortium, LLNL and Kaiser Aluminum are conducting experimental and numerical studies on crashworthy aluminum spaceframe designs. They have jointly explored the effect of heat treat on crush behavior and duplicated the experimental behavior with finite-element simulations. The major technical contributions to the state of the art in numerical simulation arise from the development and use of advanced material model descriptions for LLNL`s DYNA3D code. Constitutive model enhancements in both flow and failure have been employed for conventional materials such as low-carbon steels, and also for lighter weight materials such as aluminum and fiber compositesmore » being considered for future vehicles. The constitutive model enhancements are developed as extensions from LLNL`s work in anisotropic flow and multiaxial failure modeling. Analysis quality as a function of level of simplification of material behavior and mesh is explored, as well as the penalty in computation cost that must be paid for using more complex models and meshes. The lightweight material modeling technology is being used at the vehicle component level to explore the safety implications of small neighborhood electric vehicles manufactured almost exclusively from these materials.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
D'Amours, Guillaume; Rahem, Ahmed; Mayer, Robert
2007-05-17
The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash performance of automotive structural components must be better understood to ensure improved crashworthiness. This paper presents results of an experimental and numerical investigation of the crash response and energy absorption properties of impacted hydroformed aluminium alloy tubes. Crash experiments onmore » hydroformed tubes were performed using a deceleration sled test at the General Motors Technical Center. Results from axial crush testing showed that an important parameter that influences the energy absorption characteristics during crash was the thickness reduction caused by circumferential expansion of the tube during hydroforming. It was found that that the energy absorption decreased as the corner radius decreased, which results because of increased thinning. Sensitivity studies of end feeding parameters, such as end feed level and profile, were carried out to evaluate their impact on the energy absorption of the aluminium tubes.« less
Crashworthiness Design of the Shear Bolts for Light Collision Safety Devices
NASA Astrophysics Data System (ADS)
Kim, Jin Sung; Huh, Hoon; Kwon, Tae Soo
This paper introduces the jig set for the crash test and the crash test results of shear bolts which are designed to fail at train crash conditions. The tension and shear bolts are attached to Light Collision Safety Devices(LCSD) as a mechanical fuse when tension and shear bolts reach their failure load designed. The kinetic energy due to the crash is absorbed by the secondary energy absorbing device after LCSD are detached from the main body by the fracture of shear bolts. A single shear bolt was designed to fail at the load of 250 kN. The jig set designed to convert a compressive loading to a shear loading was installed to the high speed crash tester for dynamic shear tests. Two strain gauges were attached at the parallel section of the jig set to measure the load responses acting on the shear bolts. Crash tests were performed with a carrier whose mass was 250 kg and the initial speed of the carrier was 9 m/sec. From the quasi-static and dynamic experiments as well as the numerical analysis, the capacity of the shear bolts were accurately predicted for the crashworthiness design.
NASA Astrophysics Data System (ADS)
D'Amours, Guillaume; Rahem, Ahmed; Mayer, Robert; Williams, Bruce; Worswick, Michael
2007-05-01
The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash performance of automotive structural components must be better understood to ensure improved crashworthiness. This paper presents results of an experimental and numerical investigation of the crash response and energy absorption properties of impacted hydroformed aluminium alloy tubes. Crash experiments on hydroformed tubes were performed using a deceleration sled test at the General Motors Technical Center. Results from axial crush testing showed that an important parameter that influences the energy absorption characteristics during crash was the thickness reduction caused by circumferential expansion of the tube during hydroforming. It was found that that the energy absorption decreased as the corner radius decreased, which results because of increased thinning. Sensitivity studies of end feeding parameters, such as end feed level and profile, were carried out to evaluate their impact on the energy absorption of the aluminium tubes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jacovides, L.J.; Cornell, E.P.; Kirk, R.
1981-01-01
A study of the energy utilization of gasoline and battery-electric powered special purpose vehicles is discussed along with the impact of electric cars on national energy consumption, the development of electric vehicles in Japan, the applicability of safety standards to electric and hybrid-vehicles, and crashworthiness tests on two electric vehicles. Aspects of energy storage are explored, taking into account a review of battery systems for electrically powered vehicles, the dynamic characterization of lead-acid batteries for vehicle applications, nickel-zinc storage batteries as energy sources for electric vehicles, and a high energy tubular battery for a 1800 kg payload electric delivery van.more » Subjects considered in connection with drive systems include the drive system of the DOE near-term electric vehicle, a high performance AC electric drive system, an electromechanical transmission for hybrid vehicle power trains, and a hybrid vehicle for fuel economy. Questions of vehicle development are examined, giving attention to the Electrovair electric car, special purpose urban cars, the system design of the electric test vehicle, a project for city center transport, and a digital computer program for simulating electric vehicle performance.« less
Safe structures for future aircraft
NASA Technical Reports Server (NTRS)
Mccomb, H. G., Jr.
1983-01-01
The failure mechanisms, design lessons, and test equipment employed by NASA in establishing the airworthiness and crashworthiness of aircraft components for commercial applications are described. The composites test programs have progressed to medium primary structures such as stabilizers and a vertical fin. The failures encountered to date have been due to the nonyielding nature of composites, which do not diffuse loads like metals, and the presence of eccentricities, irregular shapes, stiffness changes, and discontinuities that cause tension and shear. Testing to failure, which always occurred in first tests before the design loads were reached, helped identify design changes and reinforcements that produced successful products. New materials and NDE techniques are identified, together with aircraft structural design changes that offer greater protection to the passengers, fuel antimisting agents, and landing gear systems.
Study of aircraft crashworthiness for fire protection
NASA Technical Reports Server (NTRS)
Cominsky, A.
1981-01-01
Impact-survivable postcrash fire accidents were surveyed. The data base developed includes foreign and domestic accidents involving airlines and jet aircraft. The emphasis was placed on domestic accidents, airlines, and jet aircraft due principally to availability of information. Only transport category aircraft in commercial service designed under FAR Part 25 were considered. A matrix was prepared to show the relationships between the accident characteristics and the fire fatalities. Typical postcrash fire scenaries were identified. Safety concepts were developed for three engineering categories: cabin interiors - cabin subsystems; power plant - engines and fuel systems; and structural mechanics - primary and secondary structures. The parameters identified for concept evaluation are cost, effectiveness, and societal concerns. Three concepts were selected for design definition and cost and effectiveness analysis: improved fire-resistant seat materials; anti-misting kerosene; and additional cabin emergency exits.
1963-06-11
Ames aerodynamicists tested a wide variety of VTOL aircraft and helicopters during the 1960's Here the Hiller rotorcycle YROE-1, made by Hiller Helicopter in nearby Palo Alto, California, hovers in front of the Ames Hangar. The Rotorcycle was a small, 500pound, single-place helicopter. Tests indicated that the vehicle was unsafe because of low yaw-control capability to the right; the design also had oor crashworthiness.
Structural Crashworthiness and Failure
1993-04-16
body motion occurs. This rigid -plastic idealization for dynamically loaded structures is based upon the fact that the plastic deformation of a...in general, for any tensor variable x, i represents the convective derivative. It should be noted that the rigid body rotation is included in the...clamped, impulsively loaded, rigid - plastic beam.’ (a) First phase of motion with stationary transverse plastic hinges at A and E and stationary plastic
1986-04-01
fuel forward-inertia loadings are applied to ribs in swept wing boxes. The assumed decelerations can be improved upon by treating the aircraft as a...the experience gained, combined with the emergence of smart graphics and cheaper computing power will see an increase in finite element derived...different facets, each of them requiring deep insight, and often interacting to eachother . The different issues that must contribute to the development
Code of Federal Regulations, 2010 CFR
2010-10-01
... requirements of § 229.205 for the type of locomotive design or provides at least an equivalent level of safety... least an equivalent level of safety. Types of data and analysis to be considered are described in § 229.211(c)(1). (d) Petitions for FRA approval of non-substantive changes to the existing FRA-approved...
Development of a time sensitivity score for frequently occurring motor vehicle crash injuries.
Schoell, Samantha L; Doud, Andrea N; Weaver, Ashley A; Talton, Jennifer W; Barnard, Ryan T; Martin, R Shayn; Meredith, J Wayne; Stitzel, Joel D
2015-03-01
Injury severity alone is a poor indicator of the time sensitivity of injuries. The purpose of the study was to quantify the urgency with which the most frequent motor vehicle crash injuries require treatment, according to expert physicians. The time sensitivity was quantified for the top 95% most frequently occurring Abbreviated Injury Scale (AIS) 2+ injuries in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) 2000-2011. A Time Sensitivity Score was developed using expert physician survey data in which physicians were asked to determine whether a particular injury should go to a Level I/II trauma center and the urgency with which that injury required treatment. When stratifying by AIS severity, the mean Time Sensitivity Score increased with increasing AIS severity. The mean Time Sensitivity Scores by AIS severity were as follows: 0.50 (AIS 2); 0.78 (AIS 3); 0.92 (AIS 4); 0.97 (AIS 5); and 0.97 (AIS 6). When stratifying by anatomical region, the head, thorax, and abdomen were the most time sensitive. Appropriate triage depends on multiple factors, including the severity of an injury, the urgency with which it requires treatment, and the propensity of a significant injury to be missed. The Time Sensitivity Score did not correlate highly with the widely used AIS severity scores, which highlights the inability of AIS scores to capture all aspects of injury severity. The Time Sensitivity Score can be useful in Advanced Automatic Crash Notification systems for identifying highly time sensitive injuries in motor vehicle crashes requiring prompt treatment at a trauma center. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.
Characteristics of pregnant women in motor vehicle crashes
Weiss, H; Strotmeyer, S
2002-01-01
Objectives: Motor vehicle crashes are the leading cause of hospitalized trauma during pregnancy. Maternal injury puts the fetus at great risk, yet little is known about the incidence, risks, and characteristics of pregnant women in crashes. Setting and methods: Police reported crashes were analyzed from the National Automotive Sampling System Crashworthiness Data System. Since 1995, this system recorded pregnancy/trimester status. Pregnant and non-pregnant women 15–39 years of age were compared by age, driver status, seat belt use, and treatment. Belt use and seating position were examined by trimester. Results: There were 427 pregnant occupants identified (weighted n=32 810, 2.6%, SE 12 585, rate 13/1000 person years). The mean age was 24.9 compared with 24.8 years (pregnant v non-pregnant). Cases were distributed by trimester as follows: first 29.8%, second 36.4%, and third 33.8%. Pregnant women were drivers 70% of the time compared with 71% for non-pregnant women. No belt use was 14% compared with 13% (pregnant v non-pregnant). Mean injury severity was lower for pregnant women but they were more likely to transported or hospitalized. Improper belt use decreased after the first trimester and there was little change in driver proportion by trimester. Third trimester hospitalization rates increased. Conclusions: Pregnant occupants in crashes have similar profiles of restraint use, driver status, and seat position but different treatment indicators compared to non-pregnant occupants. Trimester status has relatively little impact on crash risk, seating position or restraint use. Undercounting of pregnant cases was possible, even so, 1% of all births were reported to be involved in utero in crashes. Little research has focused on developmental outcomes to infants and children previously involved in exposure to these crashes. PMID:12226117
Kononen, Douglas W; Flannagan, Carol A C; Wang, Stewart C
2011-01-01
A multivariate logistic regression model, based upon National Automotive Sampling System Crashworthiness Data System (NASS-CDS) data for calendar years 1999-2008, was developed to predict the probability that a crash-involved vehicle will contain one or more occupants with serious or incapacitating injuries. These vehicles were defined as containing at least one occupant coded with an Injury Severity Score (ISS) of greater than or equal to 15, in planar, non-rollover crash events involving Model Year 2000 and newer cars, light trucks, and vans. The target injury outcome measure was developed by the Centers for Disease Control and Prevention (CDC)-led National Expert Panel on Field Triage in their recent revision of the Field Triage Decision Scheme (American College of Surgeons, 2006). The parameters to be used for crash injury prediction were subsequently specified by the National Expert Panel. Model input parameters included: crash direction (front, left, right, and rear), change in velocity (delta-V), multiple vs. single impacts, belt use, presence of at least one older occupant (≥ 55 years old), presence of at least one female in the vehicle, and vehicle type (car, pickup truck, van, and sport utility). The model was developed using predictor variables that may be readily available, post-crash, from OnStar-like telematics systems. Model sensitivity and specificity were 40% and 98%, respectively, using a probability cutpoint of 0.20. The area under the receiver operator characteristic (ROC) curve for the final model was 0.84. Delta-V (mph), seat belt use and crash direction were the most important predictors of serious injury. Due to the complexity of factors associated with rollover-related injuries, a separate screening algorithm is needed to model injuries associated with this crash mode. Copyright © 2010 Elsevier Ltd. All rights reserved.
Full Spectrum Crashworthiness Criteria for Rotorcraft
2011-12-01
hydraulic orifice and metering pin technologies. One drawback of this technology is that the shock strut loads can exceed the design strength allowable...where the velocity v is to be computed. For example, using a pendulum -style swing method for full-scale aircraft crash tests introduces a pitch...performed at LandIR using a parallel pendulum swing technique (Figure 6-10). Equidistant pivot-point platforms are located at the top of the gantry
CRASHWORTHY TROOP SEAT INVESTIGATION
1974-12-01
helicopter structure and landing gear. Newly de - signed helicopters will have landing gear designed to with- stand high sink rates and structure whioh provides...when there is no ___ ditb i- the-restrant s tystem s p§’-Hardware components sAiall carry the restraint harness design loads without permanent de ...Specification can be accepted, a troop seat design must be tested to demonstrate compliance with the proposed draft General Military Specification. Such
Crashworthy Gunner Seat Testing Program
1977-03-01
147 5 LIST OF ILLUSTRATIONS Page 1. Swivel Gunner Seat Mock-up 14 2. Ceiling and Floor Swivel Rings .... ........... 16 3. Wire - Bending Tension...History . 57 37. Test 1 - Vertical Acceleration, Dummy Pelvis . 58 38. Upper Wire - bending Attenuators, Force/Duflection 59 39 Pre-test 2, 900 to Impact...unobstructed depth to permit lateral movement in the seat for gunnery operations. Wire - bending energy attenuators are located at the top of the two vertical
YAH-63 Helicopter Crashworthiness Simulation and Analysis
1983-02-01
had dual 6.00-6 tires and wheels with full caster attachment to a support strut which incorporated a shimmy damper, self- centering device, and swivel...modeled in detail. Each struo- "tural member, link, and wheel of the nose and main landing gears was modeled and th. shook strut properties were derived...COMPARISON ....................... 80 6.1 KRASH Model Modifications ................. 80 6.2 Comparison of Overall Structural Response. 82 6.3 Landing
DOE Office of Scientific and Technical Information (OSTI.GOV)
D'Amours, Guillaume; Rahem, Ahmed; Williams, Bruce
2007-05-17
The automotive industry, with an increasing demand to reduce vehicle weight through the adoption of lightweight materials, requires a search of efficient methods that suit these materials. One attractive concept is to use hydroforming of aluminium tubes. By using FE simulations, the process can be optimized to reduce the risk for failure while maintaining energy absorption and component integrity under crash conditions. It is important to capture the level of residual ductility after forming to allow proper design for crashworthiness. This paper presents numerical and experimental studies that have been carried out for high pressure hydroforming operations to study themore » influence of the tube corner radius, end feeding, material thinning, and work hardening in 76.2 mm diameter, 3 mm wall thickness AA5754 aluminium alloy tube. End feeding was used to increase the formability of the tubes. The influence of the end feed displacement versus tube forming pressure schedule was studied to optimize the forming process operation to reduce thinning. Validation of the numerical simulations was performed by comparison of the predicted strain distributions and thinning, with measured quantities. The effect of element formulation (thin shell versus solid elements) was also considered in the models.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Northrop, G.M.
1975-06-01
Societal consequences of the availability, under Title II, Public Law 92-513, of information on crashworthiness, crash repair cost, routine maintenance and repair cost, and insurance cost are investigated. Surveys of small groups of private passenger car buyers and fleet buyers were conducted, and the results were analyzed. Three simple computer models were prepared: (1) an Accident Model to compare the number of occupants suffering fatal or serious injuries under assumed car-buying behavior with and without the availability of Title II information and changes made by car manufacturers that modify crashworthiness and car weight; (2) a New Car Sales Model tomore » determine the impact of car-buying behavior on 22 societal elements involving consumer expenditures and employment, sales margin, and value added for dealers, car manufacturers, and industrial suppliers; and (3) a Car Operations Model to determine the impact of car-buying behavior on the total gasoline consumption cost, crash repair cost, routine maintenance, repair cost, and insurance cost. Projections of car-buying behavior over a 10-year period (1976-1985) were made and results presented in the form of 10-year average values of the percent difference between results under 'With Title II' and 'Without Title II' information.« 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.
Injury risk among children in motor vehicle crashes: older versus younger drivers.
Bromfield, Samantha G; McGwin, Gerald
2014-11-01
To explore the relationship between injury risk among child occupants involved in motor vehicle collisions according to the age of the vehicle driver. The National Automotive Sampling System Crashworthiness Data System 2000-2009 (n = 10 797) was used to identify demographic, vehicle-, collision- and injury-related characteristics among motor vehicle collision occupants ≤15 years of age. The association between the age of the driver (older vs. younger, defined as individuals <50 years of age vs. individuals ≥50 years of age, respectively) and injury occurrence was estimated using logistic regression adjusting for the potentially confounding effect of occupant, vehicle and collision characteristics. Of the child occupants in motor vehicle collisions, 2.9% were driving with an older driver, and approximately 2.9% were injured while driving with a younger driver (odds ratio 1.03; 95% confidence interval 0.55-1.91). After adjusting for child occupant age, gender, restraint use, seat position and vehicle type, there remained no significant association between the age of the driver (older vs. younger) and the risk of injury (odds ratio 0.92; 95% confidence interval 0.49-1.74). These findings add to the body of literature indicating no difference in injury risk found among children when considering the age of the driver. Research is needed to ascertain the association and further evaluate characteristics more specific to the relationship being explored in this study. © 2014 The Authors. Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).
Head Injury and Aging: The Importance of Bleeding Injuries
Mallory, Ann
The current study analyzed 1993–2007 data from NASS/CDS (National Automotive Sampling System / Crashworthiness Data System) to explore the types of serious head injuries sustained by adult motor vehicle crash occupants and how the types of head injuries sustained shifted with age. The purpose was to determine which head injuries are most important for older occupants by identifying specific injuries that become more likely for aging occupants and taking into consideration previous reports on the potential outcome of those injuries for an older population. Results confirmed previous reports that older head injury victims in motor vehicle collisions were more likely to sustain bleeding injuries than younger head injury victims. The current study showed that, in particular, the rate of extra-axial bleeding injury (which includes epidural, subdural, and subarachnoid bleeding) increased with age. The increase in extra-axial bleeding injury rate was especially prominent in relatively low Delta-V crashes. Among the extra-axial bleeding injuries that had increased odds of injury for older occupants, subdural hematoma and subarachnoid hemorrhage were notable, with increased odds of injury for occupants age 50 to 69 as well as for occupants age 70 and older. The importance of subdural hematoma for aging occupants is emphasized by previous studies showing its high mortality rate, while the impact of subarachnoid hemorrhage is linked in previous studies to its aggravating effect on other injuries. The results highlight a need to further explore the injury mechanisms of subdural hematoma and subarachnoid hemorrhage in older occupants in order to define age-adjusted injury tolerance and develop countermeasures. PMID:21050591
NASA Technical Reports Server (NTRS)
Noor, A. K. (Editor); Housner, J. M.
1983-01-01
The mechanics of materials and material characterization are considered, taking into account micromechanics, the behavior of steel structures at elevated temperatures, and an anisotropic plasticity model for inelastic multiaxial cyclic deformation. Other topics explored are related to advances and trends in finite element technology, classical analytical techniques and their computer implementation, interactive computing and computational strategies for nonlinear problems, advances and trends in numerical analysis, database management systems and CAD/CAM, space structures and vehicle crashworthiness, beams, plates and fibrous composite structures, design-oriented analysis, artificial intelligence and optimization, contact problems, random waves, and lifetime prediction. Earthquake-resistant structures and other advanced structural applications are also discussed, giving attention to cumulative damage in steel structures subjected to earthquake ground motions, and a mixed domain analysis of nuclear containment structures using impulse functions.
NASA's aviation safety research and technology program
NASA Technical Reports Server (NTRS)
Fichtl, G. H.
1977-01-01
Aviation safety is challenged by the practical necessity of compromising inherent factors of design, environment, and operation. If accidents are to be avoided these factors must be controlled to a degree not often required by other transport modes. The operational problems which challenge safety seem to occur most often in the interfaces within and between the design, the environment, and operations where mismatches occur due to ignorance or lack of sufficient understanding of these interactions. Under this report the following topics are summarized: (1) The nature of operating problems, (2) NASA aviation safety research, (3) clear air turbulence characterization and prediction, (4) CAT detection, (5) Measurement of Atmospheric Turbulence (MAT) Program, (6) Lightning, (7) Thunderstorm gust fronts, (8) Aircraft ground operating problems, (9) Aircraft fire technology, (10) Crashworthiness research, (11) Aircraft wake vortex hazard research, and (12) Aviation safety reporting system.
Structural response of transport airplanes in crash situations
NASA Technical Reports Server (NTRS)
Thomson, R. G.; Caiafa, C.
1983-01-01
This report highlights the results of contractural studies of transport accident data undertaken in a joint research program sponsored by the FAA and NASA. From these accident data studies it was concluded that the greatest potential for improved transport crashworthiness is in the reduction of fire related fatalities. Accident data pertaining to fuselage integrity, main landing gear collapse, fuel tank rupture, wing breaks, tearing of tank lower surfaces, and engine pod scrubbing are discussed. In those accidents where the energy absorbing protective capability of the fuselage structure is expended and the airplane experiences major structural damage, trauma caused fatalities are also discussed. The dynamic performance of current seat/restraint systems are examined but it is concluded that the accident data does not adequately define the relationship between occupant response and the dynamic interaction with the seat, floor and fuselage structure.
Ma, Xiaoguang; Griffin, Russell; McGwin, Gerald; Allison, David B.; Heymsfield, Steven B.; He, Wei; Zhu, Shankuan
2013-01-01
Objectives The objective was to evaluate the effectiveness of belt-positioning booster seats, compared with no restraint use and with seat belt use only, during motor vehicle crashes among U.S. children. Methods This was a retrospective matched cohort study with data from the 1998 through 2009 National Automotive Sampling System (NASS) Crashworthiness Data System (CDS). The study sample consisted of children aged 0 to 10 years who were not seated in the front seat of the vehicle. We used Cox proportional hazards models to estimate the risk of overall, fatal, and regional body injury. Results Children using seat belts in belt-positioning booster seats experienced less overall injury (Injury Severity Score [ISS] > 0, adjusted risk ratio [RR] = 0.73, 95% confidence interval [CI] = 0.55 to 0.96; Abbreviated Injury Scale [AIS] score of 2 or higher, adjusted RR = 0.30, 95% CI = 0.16 to 0.58; ISS > 8, adjusted RR = 0.19, 95% CI = 0.06 to 0.56), and less injury in most body regions except the neck (adjusted RR = 4.79, 95% CI = 1.43 to 16.00) than did children with no restraint use. Children using seat belts in belt-positioning booster seats had an equal risk of injury but higher risks of neck (adjusted RR = 1.86, 95% CI = 1.02 to 3.40) and thorax (adjusted RR = 2.86, 95% CI = 1.33 to 6.15) injury than did children restrained by seat belts only. Conclusions Children using belt-positioning booster seats appear to experience a higher risk of AIS > 0 injury to the neck and thorax than do children using seat belts only. Future research should examine whether the observed increase in neck and thorax injuries can be attributed to improper use of booster seats. PMID:24050794
Lateral automobile impacts and the risk of traumatic brain injury.
Bazarian, Jeffrey J; Fisher, Susan Gross; Flesher, William; Lillis, Robert; Knox, Kerry L; Pearson, Thomas A
2004-08-01
We determine the relative risk and severity of traumatic brain injury among occupants of lateral impacts compared with occupants of nonlateral impacts. This was a secondary analysis of the National Highway Traffic Safety Administration's National Automotive Sampling System, Crashworthiness Data Systems for 2000. Analysis was restricted to occupants of vehicles in which at least 1 person experienced an injury with Abbreviated Injury Scale score greater than 2. Traumatic brain injury was defined as an injury to the head or skull with an Abbreviated Injury Scale score greater than 2. Outcomes were analyzed using the chi2 test and multivariate logistic regression, with adjustment of variance to account for weighted probability sampling. Of the 1,115 occupants available for analysis, impact direction was lateral for 230 (18.42%) occupants and nonlateral for 885 (81.58%) occupants. One hundred eighty-seven (16.07%) occupants experienced a traumatic brain injury, 14.63% after lateral and 16.39% after nonlateral impact. The unadjusted relative risk of traumatic brain injury after lateral impact was 0.89 (95% confidence interval [CI] 0.51 to 1.56). After adjusting for several important crash-related variables, the relative risk of traumatic brain injury was 2.60 (95% CI 1.1 to 6.0). Traumatic brain injuries were more severe after lateral impact according to Abbreviated Injury Scale and Glasgow Coma Scale scores. The proportion of fatal or critical crash-related traumatic brain injuries attributable to lateral impact was 23.5%. Lateral impact is an important independent risk factor for the development of traumatic brain injury after a serious motor vehicle crash. Traumatic brain injuries incurred after lateral impact are more severe than those resulting from nonlateral impact. Vehicle modifications that increase head protection could reduce crash-related severe traumatic brain injuries by up to 61% and prevent up to 2,230 fatal or critical traumatic brain injuries each year in the United States.
In-plane crashworthiness of bio-inspired hierarchical honeycombs
Yin, Hanfeng; Huang, Xiaofei; Scarpa, Fabrizio; ...
2018-03-13
Biological tissues like bone, wood, and sponge possess hierarchical cellular topologies, which are lightweight and feature an excellent energy absorption capability. Here we present a system of bio-inspired hierarchical honeycomb structures based on hexagonal, Kagome, and triangular tessellations. The hierarchical designs and a reference regular honeycomb configuration are subjected to simulated in-plane impact using the nonlinear finite element code LS-DYNA. The numerical simulation results show that the triangular hierarchical honeycomb provides the best performance compared to the other two hierarchical honeycombs, and features more than twice the energy absorbed by the regular honeycomb under similar loading conditions. We also proposemore » a parametric study correlating the microstructure parameters (hierarchical length ratio r and the number of sub cells N) to the energy absorption capacity of these hierarchical honeycombs. The triangular hierarchical honeycomb with N = 2 and r = 1/8 shows the highest energy absorption capacity among all the investigated cases, and this configuration could be employed as a benchmark for the design of future safety protective systems.« less
In-plane crashworthiness of bio-inspired hierarchical honeycombs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yin, Hanfeng; Huang, Xiaofei; Scarpa, Fabrizio
Biological tissues like bone, wood, and sponge possess hierarchical cellular topologies, which are lightweight and feature an excellent energy absorption capability. Here we present a system of bio-inspired hierarchical honeycomb structures based on hexagonal, Kagome, and triangular tessellations. The hierarchical designs and a reference regular honeycomb configuration are subjected to simulated in-plane impact using the nonlinear finite element code LS-DYNA. The numerical simulation results show that the triangular hierarchical honeycomb provides the best performance compared to the other two hierarchical honeycombs, and features more than twice the energy absorbed by the regular honeycomb under similar loading conditions. We also proposemore » a parametric study correlating the microstructure parameters (hierarchical length ratio r and the number of sub cells N) to the energy absorption capacity of these hierarchical honeycombs. The triangular hierarchical honeycomb with N = 2 and r = 1/8 shows the highest energy absorption capacity among all the investigated cases, and this configuration could be employed as a benchmark for the design of future safety protective systems.« less
Physical properties of the human head: mass, center of gravity and moment of inertia.
Yoganandan, Narayan; Pintar, Frank A; Zhang, Jiangyue; Baisden, Jamie L
2009-06-19
This paper presents a synthesis of biomedical investigations of the human head with specific reference to certain aspects of physical properties and development of anthropometry data, leading to the advancement of dummies used in crashworthiness research. As a significant majority of the studies have been summarized as reports, an effort has been made to chronologically review the literature with the above objectives. The first part is devoted to early studies wherein the mass, center of gravity (CG), and moment of inertia (MOI) properties are obtained from human cadaver experiments. Unembalmed and preserved whole-body and isolated head and head-neck experiments are discussed. Acknowledging that the current version of the Hybrid III dummy is the most widely used anthropomorphic test device in motor vehicle crashworthiness research for frontal impact applications for over 30 years, bases for the mass and MOI-related data used in the dummy are discussed. Since the development and federalization of the dummy in the United States, description of methods used to arrive at these properties form a part of the manuscript. Studies subsequent to the development of this dummy including those from the US Military are also discussed. As the head and neck are coupled in any impact, and increasing improvements in technology such as advanced airbags, and pre-tensioners and load limiters in manual seatbelts affect the kinetics of the head-neck complex, the manuscript underscores the need to pursue studies to precisely determine all the physical properties of the head. Because the most critical parameters (locations of CG and occipital condyles (OC), mass, and MOI) have not been determined on a specimen-by-specimen basis in any single study, it is important to gather these data in future experiments. These critical data will be of value for improving occupant safety, designing advanced restraint systems, developing second generation dummies, and assessing the injury mitigating characteristics of modern vehicle components in all impact modalities.
Comprehensive target populations for current active safety systems using national crash databases.
Kusano, Kristofer D; Gabler, Hampton C
2014-01-01
The objective of active safety systems is to prevent or mitigate collisions. A critical component in the design of active safety systems is the identification of the target population for a proposed system. The target population for an active safety system is that set of crashes that a proposed system could prevent or mitigate. Target crashes have scenarios in which the sensors and algorithms would likely activate. For example, the rear-end crash scenario, where the front of one vehicle contacts another vehicle traveling in the same direction and in the same lane as the striking vehicle, is one scenario for which forward collision warning (FCW) would be most effective in mitigating or preventing. This article presents a novel set of precrash scenarios based on coded variables from NHTSA's nationally representative crash databases in the United States. Using 4 databases (National Automotive Sampling System-General Estimates System [NASS-GES], NASS Crashworthiness Data System [NASS-CDS], Fatality Analysis Reporting System [FARS], and National Motor Vehicle Crash Causation Survey [NMVCCS]) the scenarios developed in this study can be used to quantify the number of police-reported crashes, seriously injured occupants, and fatalities that are applicable to proposed active safety systems. In this article, we use the precrash scenarios to identify the target populations for FCW, pedestrian crash avoidance systems (PCAS), lane departure warning (LDW), and vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) systems. Crash scenarios were derived using precrash variables (critical event, accident type, precrash movement) present in all 4 data sources. This study found that these active safety systems could potentially mitigate approximately 1 in 5 of all severity and serious injury crashes in the United States and 26 percent of fatal crashes. Annually, this corresponds to 1.2 million all severity, 14,353 serious injury (MAIS 3+), and 7412 fatal crashes. In addition, we provide the source code for the crash scenarios as an appendix (see online supplement) to this article so that researchers can use the crash scenarios in future research.
Modelling of structural flexiblity in multibody railroad vehicle systems
NASA Astrophysics Data System (ADS)
Escalona, José L.; Sugiyama, Hiroyuki; Shabana, Ahmed A.
2013-07-01
This paper presents a review of recent research investigations on the computer modelling of flexible bodies in railroad vehicle systems. The paper will also discuss the influence of the structural flexibility of various components, including the wheelset, the truck frames, tracks, pantograph/catenary systems, and car bodies, on the dynamics of railroad vehicles. While several formulations and computer techniques for modelling structural flexibility are discussed in this paper, a special attention is paid to the floating frame of reference formulation which is widely used and leads to reduced-order finite-element models for flexible bodies by employing component modes synthesis techniques. Other formulations and numerical methods such as semi-analytical approaches, absolute nodal coordinate formulation, finite-segment method, boundary elements method, and discrete elements method are also discussed. This investigation is motivated by the fact that the structural flexibility can have a significant effect on the overall dynamics of railroad vehicles, ride comfort, vibration suppression and noise level reduction, lateral stability, track response to vehicle forces, stress analysis, wheel-rail contact forces, wear and crashworthiness.
CRASHWORTHY HELICOPTER GUNNER’S SEAT INVESTIGATION
1975-01-01
less restrict- ing to gun motion than a fully armored bucket seat. The problem remains in getting the gunners to wear body armor, and this can be... motions . The adjustable seat back accommodates a gun- ner with or without body armor and troops with or without combat packs and equipment. A back flap...Developmental Retractable Monkey Harness Restraint for UH-l 1 1.9 10 Gunner Survival Vest With Body Armor (ISVESTA) Side View . . . . . . . . *. . ... .. 22
Risk of thoracic injury from direct steering wheel impact in frontal crashes.
Chen, Rong; Gabler, Hampton C
2014-06-01
The combination of airbag and seat belt is considered to be the most effective vehicle safety system. However, despite the widespread availability of airbags and a belt use rate of more than 85%, US drivers involved in crashes continue to be at risk of serious thoracic injury. The objective of this study was to determine the influence of steering wheel deformation on driver injury risk in frontal automobile crash. The analysis is based on cases extracted from the National Automotive Sampling System Crashworthiness Data System database for case years 1993 to 2011. The approach was to compare the adjusted odds of frontal crash injury experienced by drivers in vehicles with and without steering wheel deformation. Among frontal crash cases with belted drivers, observable steering wheel deformation occurred in less than 4% of all cases but accounted for 30% of belted drivers with serious (Abbreviated Injury Scale [AIS] score, 3+) thoracic injuries. Similarly, steering wheel deformation occurred in approximately 13% of unbelted drivers but accounted for 60% of unbelted drivers with serious thoracic injuries. Belted drivers in frontal crashes with steering wheel deformation were found to have two times greater odds of serious thoracic injury. Unbelted drivers were found to have four times greater odds of serious thoracic injury in crashes with steering wheel deformation. In frontal crashes, steering wheel deformation was more likely to occur in unbelted drivers than belted drivers, as well as higher severity crashes and with heavier drivers. The results of the present study show that airbag deployment and seat belt restraint do not completely eliminate the possibility of steering wheel contact. Even with the most advanced restraint systems, there remains an opportunity for further reduction in thoracic injury by continued enhancement to the seat belt and airbag systems. Furthermore, the results showed that steering wheel deformation is an indicator of potential serious thoracic injury and can be useful to prehospital personnel in improving the diagnosis of serious injuries. Prognostic study, level III.
Cormier, Joseph; Gwin, Lisa; Reinhart, Lars; Wood, Rawson; Bain, Charles
2018-02-27
This study combined all prior research involving human volunteers in low-speed rear-end impacts and performed a comparative analysis of real-world crashes using the National Automotive Sampling System - Crashworthiness Data System. The aim of this study was to assess the rates of neck pain between volunteer and real-world collisions as well as the likelihood of an injury beyond symptoms as a function of impact severity and occupant characteristics in real-world collisions. A total of 51 human volunteer studies were identified that produced a dataset of 1984 volunteer impacts along with a separate dataset of 515,601 weighted occupants in real-world rear impacts. Operating-characteristic curves were created to assess the utility of the volunteer dataset in making predictions regarding the overall population. Change in speed or delta-V was used to model the likelihood of reporting symptoms in both real-world and volunteer exposures and more severe injuries using real-world data. Logistic regression models were created for the volunteer data and survey techniques were used to analyze the weighted sampling scheme with the National Automotive Sampling System database. Symptom reporting rates were not different between males and females and were nearly identical between laboratory and real-world exposures. The minimal risk of injury predicted by real-world exposure is consistent with the statistical power of the large number of volunteer studies without any injury beyond the reporting of neck pain. This study shows that volunteer studies do not under-report symptoms and are sufficient in number to conclude that the risk of injury beyond neck strain under similar conditions is essentially zero. The real-world injury analyses demonstrate that rear impacts do not produce meaningful risks of cervical injury at impacts of similar and greater severity to those of the volunteer research. Future work concerning the mechanism of whiplash-related trauma should focus on impacts of severity greater than those in the current literature. 3This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0.
NASA Astrophysics Data System (ADS)
Mozumder, Chandan K.
The objective in crashworthiness design is to generate plastically deformable energy absorbing structures which can satisfy the prescribed force-displacement (FD) response. The FD behavior determines the reaction force, displacement and the internal energy that the structure should withstand. However, attempts to include this requirement in structural optimization problems remain scarce. The existing commercial optimization tools utilize models under static loading conditions because of the complexities associated with dynamic/impact loading. Due to the complexity of a crash event and the consequent time required to numerically analyze the dynamic response of the structure, classical methods (i.e., gradient-based and direct) are not well developed to solve this undertaking. This work presents an approach under the framework of the hybrid cellular automaton (HCA) method to solve the above challenge. The HCA method has been successfully applied to nonlinear transient topology optimization for crashworthiness design. In this work, the HCA algorithm has been utilized to develop an efficient methodology for synthesizing shell-based sheet metal structures with optimal material thickness distribution under a dynamic loading event using topometry optimization. This method utilizes the cellular automata (CA) computing paradigm and nonlinear transient finite element analysis (FEA) via ls-dyna. In this method, a set field variables is driven to their target states by changing a convenient set of design variables (e.g., thickness). These rules operate locally in cells within a lattice that only know local conditions. The field variables associated with the cells are driven to a setpoint to obtain the desired structure. This methodology is used to design for structures with controlled energy absorption with specified buckling zones. The peak reaction force and the maximum displacement are also constrained to meet the desired safety level according to passenger safety regulations. Design for prescribed FD response by minimizing the error between the actual response and desired FD curve is implemented. With the use of HCA rules, manufacturability constraints (e.g., rolling) and structures which can be manufactured by special techniques, such as, tailor-welded blanks (TWB), have also been implemented. This methodology is applied to shock-absorbing structural components for passengers in a crashing vehicle. These results are compared to previous designs showing the benefits of the method introduced in this work.
Design considerations for composite fuselage structure of commercial transport aircraft
NASA Technical Reports Server (NTRS)
Davis, G. W.; Sakata, I. F.
1981-01-01
The structural, manufacturing, and service and environmental considerations that could impact the design of composite fuselage structure for commercial transport aircraft application were explored. The severity of these considerations was assessed and the principal design drivers delineated. Technical issues and potential problem areas which must be resolved before sufficient confidence is established to commit to composite materials were defined. The key issues considered are: definition of composite fuselage design specifications, damage tolerance, and crashworthiness.
1988-12-01
efforts dans les f~murs ou dans la colonne vert~brale. 2.1.3. Jauges 11 peut s’agir de jauges simples, doubles ou de rosettes 3 directions. Les jauges ...34, -acc~l~rombtres mannequin en "classe 180", -efforts en "classe 180", - jauges en "classe 180", -r~sultantes efforts en "classe 180", -sommes des
Commercial Jet Transport Crashworthiness
1982-04-01
airports is another area for improved safety. The avoidance of collisions between aircraft and with ground vehicles should be attainable. Reduction of...hazards such as drainage ditches, poles, trees, columns, outbuildings, and birds from airports is a matter of concern. In addition the short/overrun areas...071191 DCC DENVER X 122 17 0 LOG FIRE YES 011961 DC8 JFK X 106 4 ? TO FIRE PAR 061561 707 LISBON 103 0 2 LDG FIRE YES 122161 CMT ANKARA X 34 27 6 CLI
Preliminary Rotary Wing Full Spectrum Crashworthiness Criteria
2010-01-01
6.2.1 Injury Risk Due to Occupant Loads Cervical forces and moments are to be used to evaluate injury to the head/neck, torso acceleration is used to...injury) for dynamic neck tension (lifting forces) at the occipital condyles (C0-C1, upper neck) and cervical vertebrae (C7-T1, lower neck) are defined...Neck Compression and Shear Force Limits The maximum acceptable cervical compression and shear force limits are defined in the following table
Aluminum automotive space frames
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-08-01
Design of aluminum structures is to a new topic. Aircraft makers have successfully solved difficult structural problems with a high degree of understanding and reliability. Other transportation modes such as trucks, trailers, and railcars have faced structural problems with some emphasis on high- and low-cycle fatigue of welded aluminum structures. However, the automotive market places stringent engineering demands on materials and superimposes demanding cost constraints. A project was instituted at Reynolds Metals Co. to investigate the opportunities for the cost-effective application of aluminum to automotive spaceframes. Several areas were recognized as key to the success of this application. They were:more » equivalent or superior structural stiffness of the assembly to existing steel unibody and/or steel spaceframe vehicles; effective joining of spaceframe members; equivalent or superior crashworthiness of the assembly; weight savings; flexibility; and low-cost approach aimed at effective manufacturing. To gain experience with the key aspects in a practical environment, the experience of current builders of steel tube frame chassis was explored. These chassis are typically used in low-volume vehicles requiring torsional stiffness, excellent crashworthiness, and exterior body-style flexibility. A model was developed using finite element methods that accurately predicts mass and stiffness of frames. An effective aluminum space frame was generated which was 7.5% stiffer and more than 20% lighter than the steel frame, with stresses kept below the fatigue limit for aluminum welds.« 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
Investigation of Vehicle Rear Under Run Protection Device (RUPD) Using Aluminium Foam
NASA Astrophysics Data System (ADS)
Nagaraj Goud, B.; pachori, Avinash
2017-08-01
Whenever the passenger cars meet with accidents with the heavy duty truck from rear, it will tend to penetrate under the truck bed called truck trailer under-ride crash. This is responsible for the thousands of accidents, causing severe injuries and spot death. This is mostly due to the lack of effective guarding system. The Present paper gives an importance on energy absorption mechanism of a Rear under Run Protection Device (RUPD) under crash effect of the truck. The aim of the study is to replace Steel RUPD with aluminum foam, which promises an improvement of vehicle crashworthiness as well as to reduce weight of the vehicle. The aluminum foam is selected due to the high specific strength and specific stiffness. This inborn character makes it a promising candidate in the modern lightweight structures in the automotive engineering which can contribute to the improvement of mileage in addition to safety of the occupants.
Potential use of battery packs from NCAP tested vehicles.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lamb, Joshua; Orendorff, Christopher J.
2013-10-01
Several large electric vehicle batteries available to the National Highway Traffic Safety Administration are candidates for use in future safety testing programs. The batteries, from vehicles subjected to NCAP crashworthiness testing, are considered potentially damaged due to the nature of testing their associated vehicles have been subjected to. Criteria for safe shipping to Sandia is discussed, as well as condition the batteries must be in to perform testing work. Also discussed are potential tests that could be performed under a variety of conditions. The ultimate value of potential testing performed on these cells will rest on the level of accessmore » available to the battery pack, i.e. external access only, access to the on board monitoring system/CAN port or internal electrical access to the battery. Greater access to the battery than external visual and temperature monitoring would likely require input from the battery manufacturer.« less
Ebel, B E; Mack, C; Diehr, P; Rivara, F P
2004-10-01
In 2001, 6.3 million passengers were involved in motor vehicle crashes. This study aimed to determine the number of work days lost as a result of motor vehicle crashes and factors that influenced people's return to work. This was a retrospective, population based cohort study of occupants in motor vehicles involved in crashes from the 1993-2001 Crashworthiness Data System produced by the National Highway Traffic Safety Administration. The sample population of people aged 18-65 years included two groups: occupants who survived and were working before the crash and occupants who were injured fatally and were estimated to have been working before the crash. Multivariate linear regression was used to analyze the impact of restraint use and injury type on return to work. Overall, 30.1% of occupants of vehicles that crashed missed one or more days of work. A crash resulted in a mean 28.0 (95% confidence interval 15.8 to 40.1) days lost from work, including losses associated with fatalities. The 2.1 million working occupants of vehicles that crashed in 2001 lost a total of 60 million days of work, resulting in annual productivity losses of over $7.5 billion (2964 to 12 075). Unrestrained vehicle occupants accounted for $5.6 billion in lost productivity. Motor vehicle crashes result in large and potentially preventable productive losses that are mostly attributable to fatal injuries.
Newgard, Craig D
2008-07-01
Age is often used as a predictor of injury and mortality in motor vehicle crashes (MVCs), however, the age that defines an "older" occupant in terms of injury-risk remains unclear, as do specific injury patterns associated with increasing age. The objective of this study was to evaluate the relationship between age and serious injury (including injury patterns) for occupants involved in MVCs. This was a retrospective cohort study using a national population-based cohort of adult front-seat occupants involved in MVCs and included in the National Automotive Sampling System Crashworthiness Data System database from 1995 to 2006. The primary outcome was serious injury, defined as an abbreviated injury scale (AIS) score >/=3 in any body region. Anatomic injury patterns were also assessed by age. One hundred thousand one hundred and fifty-six adult front-seat occupants were included in the analysis, of which 14,128 (2%) were seriously injured. Age was a strong predictor of serious injury using a variety of different age covariates (categorical, continuous, and polynomial) in multivariable regression models (p<0.0001 for all). There was evidence of a strong non-linear relationship between age and serious injury (p<0.001 for comparison of non-linear to linear representation of age). There was no age that clearly defined an "older" occupant by injury risk, as the odds of injury increased with increasing age across all age groups. The proportion of serious head and extremity injuries gradually increased with increasing age, while serious chest injuries markedly increased after 60 years. Age is a strong predictor of serious injury from motor vehicle trauma, the risk of which increases in non-linear fashion as age increases. There is no specific age that clearly defines an "older" occupant by injury risk.
Crash-Related Mortality and Model Year: Are Newer Vehicles Safer?
Ryb, Gabriel E; Dischinger, Patricia C; McGwin, Gerald; Griffin, Russell L
2011-01-01
Objective: The objective of this study was to determine whether occupants of newer vehicles experience a lower risk of crash-related mortality. Methods: The occurrence of death was studied in relation to vehicle model year (MY) among front seat vehicular occupants, age ≥ 16 captured in the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) between 2000 and 2008. The associations between death and other occupant, vehicular and crash characteristics were also explored. Multiple logistic regression models for the prediction of death were built with model year as the independent variable and other characteristics linked to death as covariates. Imputation was used for missing data; weighted data was used. Results: A total of 70,314 cases representing 30,514,372 weighted cases were available for analysis. Death occurred in 0.6% of the weighted population. Death was linked to age>60, male gender, higher BMI, near lateral direction of impact, high delta v, rollover, ejection and vehicle mismatch, and negatively associated with seatbelt use and rear and far lateral direction of impact. Mortality decreased with later model year groups (MY<94 0.78%, MY 94–97 0.53%, MY 98-04 0.51% and MY 05–08 0.38%, p=<0.0001). After adjustment for confounders, MY 94–97, MY 98-04 and MY 05–08 showed decreased odds of death [OR 0.80 (0.69–0.94), 0.82 (0.70–0.97), and 0.67 (0.47–0.96), respectively] when compared to MY <94. Conclusion: Newer vehicles are associated with lower crash-related mortality. Their introduction into the vehicle fleet may explain, at least in part, the decrease in mortality rates in the past two decades. PMID:22105389
Gorman, David; Handy, Ebram; Wang, Sikui; Irwin, Annette L; Wang, Stewart
2016-11-01
Previous studies of frontal crash databases reported that ankle fractures are among the most common lower extremity fractures. While not generally life threatening, these injuries can be debilitating. Laboratory research into the mechanisms of ankle fractures has linked dorsiflexion with an increased risk of tibia and fibula malleolus fractures. However, talus fractures were not produced in the laboratory tests and appear to be caused by more complex loading of the joint. In this study, an analysis of the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the years 2004-2013 was conducted to investigate foot-ankle injury rates in front seat occupants involved in frontal impact crashes. A logistic regression model was developed indicating occupant weight, impact delta velocity and gender to be significant predictors of talus fracture (p<0.05). Separately, a specific set of Computed Tomography (CT) scans from the International Center for Automotive Medicine (ICAM) scan database was used to characterize the talar dome. This control population consisted of 207 adults aged 18 to 84, with no foot or ankle trauma, and scans that had suitable coverage of the talus. Size of the talus was determined using medial-to-lateral width and anterior-to-posterior depth measurements. Geometry was assessed by evaluating the radius of the articulating talus and strength was assessed using a combination of cross sectional area and density. Demographics were studied to investigate correlation with talus measurements from the CT scan database. A multi-variable linear regression model of the morphomics showed gender to be statistically significant (p<0.05) for talus depth, width, cross-sectional area, radius and strength. Body Mass Index (BMI) was significant for depth and radius. Weight was significant for depth, width, density and strength. Stature was significant for depth, cross-sectional area, radius and strength. Age was significant for radius and density.
Manoogian, Sarah
2015-01-01
The objective of this study was to provide specific characteristics of injuries and crash characteristics for pregnant occupants from the National Automotive Sampling System/Crashworthiness Data System (NASS/CDS) database for pregnant women as a group, broken down by trimester, and compared to non-pregnant women. Using all NASS/CDS cases collected between the years 2000 and 2012 with at least one pregnant occupant, the entire pregnant data set included 321,820 vehicles, 324,535 occupants, and 640,804 injuries. The pregnant occupant data were compared to the characteristics of NASS/CDS cases for 14,719,533 non-pregnant females 13-44 years old in vehicle crashes from 2000 to 2012. Sixty five percent of pregnant women were located in the front left seat position and roughly the same percentage of pregnant women was wearing a lap and shoulder belt. The average change in velocity was 11.6 mph for pregnant women and over 50% of crashes for pregnant women were frontal collisions. From these collisions, less than seven percent of pregnant women sustained MAIS 2+ injuries. Minor differences between the pregnant and non-pregnant occupants were identified in the body region and source of injuries sustained. However, the data indicated no large differences in injury or crash characteristics based on trimester of pregnancy. Moreover, the risk of an MAIS 2+ level injury for pregnant occupants is similar to the risk of injury for non-pregnant occupants based on the total vehicle change in velocity. Overall this study provides useful data for researchers to focus future efforts in pregnant occupant research. Additionally, this study reinforces that more detailed and complete data on pregnant crashes needs to be collected to understand the risk for pregnant occupants. Copyright © 2014 Elsevier Ltd. All rights reserved.
Stitzel, Joel D; Weaver, Ashley A; Talton, Jennifer W; Barnard, Ryan T; Schoell, Samantha L; Doud, Andrea N; Martin, R Shayn; Meredith, J Wayne
2016-06-01
Advanced Automatic Crash Notification algorithms use vehicle telemetry measurements to predict risk of serious motor vehicle crash injury. The objective of the study was to develop an Advanced Automatic Crash Notification algorithm to reduce response time, increase triage efficiency, and improve patient outcomes by minimizing undertriage (<5%) and overtriage (<50%), as recommended by the American College of Surgeons. A list of injuries associated with a patient's need for Level I/II trauma center treatment known as the Target Injury List was determined using an approach based on 3 facets of injury: severity, time sensitivity, and predictability. Multivariable logistic regression was used to predict an occupant's risk of sustaining an injury on the Target Injury List based on crash severity and restraint factors for occupants in the National Automotive Sampling System - Crashworthiness Data System 2000-2011. The Advanced Automatic Crash Notification algorithm was optimized and evaluated to minimize triage rates, per American College of Surgeons recommendations. The following rates were achieved: <50% overtriage and <5% undertriage in side impacts and 6% to 16% undertriage in other crash modes. Nationwide implementation of our algorithm is estimated to improve triage decisions for 44% of undertriaged and 38% of overtriaged occupants. Annually, this translates to more appropriate care for >2,700 seriously injured occupants and reduces unnecessary use of trauma center resources for >162,000 minimally injured occupants. The algorithm could be incorporated into vehicles to inform emergency personnel of recommended motor vehicle crash triage decisions. Lower under- and overtriage was achieved, and nationwide implementation of the algorithm would yield improved triage decision making for an estimated 165,000 occupants annually. Copyright © 2016. Published by Elsevier Inc.
The effects of airbags and seatbelts on occupant injury in longitudinal barrier crashes.
Gabauer, Douglas J; Gabler, Hampton C
2010-02-01
Longitudinal barriers, such as guardrails, are designed to prevent a vehicle that leaves the roadway from impacting a more dangerous object while minimizing the risk of injury to the vehicle occupants. Current full-scale test procedures for these devices do not consider the effect of occupant restraints such as seatbelts and airbags. The purpose of this study was to determine the extent to which restraints are used or deployed in longitudinal barrier collisions and their subsequent effect on occupant injury. Binary logistic regression models were generated to predict occupant injury risk using data from the National Automotive Sampling System / Crashworthiness Data System from 1997 through 2007. In tow-away longitudinal barrier crashes, airbag deployment rates were 70% for airbag-equipped vehicles. Compared with unbelted occupants without an airbag available, seat belt restrained occupants with an airbag available had a dramatically decreased risk of receiving a serious (MAIS 3+) injury (odds-ratio (OR)=0.03; 95% CI: 0.004-0.24). A similar decrease was observed among those restrained by seat belts, but without an airbag available (OR=0.03; 95% CI: 0.001- 0.79). No significant differences in risk of serious injuries were observed between unbelted occupants with an airbag available compared with unbelted occupants without an airbag available (OR=0.53; 95% CI=0.10-2.68). This study refutes the perception in the roadside safety community that airbags rarely deploy in frontal barrier crashes, and suggests that current longitudinal barrier occupant risk criteria may over-estimate injury potential for restrained occupants involved in a longitudinal barrier crash. Copyright 2010 Elsevier Ltd. All rights reserved.
Obesity and Non-fatal Motor Vehicle Crash Injuries: Sex Difference Effects
Ma, Xiaoguang; Laud, Purushottam W.; Pintar, Frank; Kim, Jong-Eun; Shih, Alan; Shen, Wei; Heymsfield, Steven B.; Allison, David B.; Zhu, Shankuan
2010-01-01
Background Obesity and motor vehicle crash (MVC) injuries are two parallel epidemics in the United States. An important unanswered question is if there are sex differences in the associations between the presence of obesity and non-fatal MVC injuries. Objectives To further understand the association between obesity and non-fatal motor vehicle crash injuries, particularly the sex differences in these relations. Methods We examined this question by analyzing data from the 2003 to 2007 National Automotive Sampling System Crashworthiness Data System (NASS CDS). A total of 10, 962 drivers who were aged 18 years or older and who survived frontal collision crashes were eligible for study. Results Male drivers experienced a lower rate of overall non-fatal MVC injuries than did female drivers (38.1% vs. 52.2%) but a higher rate of severe injuries (0.7% vs. 0.2%). After adjusting for change in velocity (ΔV) during the crashes, obese male drivers showed a much higher risk [logistic coefficients of BMI for moderate, serious, and severe injury are 0.0766, 0.1470, and 0.1792, respectively; all p<0.05] of non-fatal injuries than did non-obese male drivers and these risks increased with injury severity. Non-fatal injury risks were not found to be increased in obese female drivers. The association between obesity and risk of non-fatal injury was much stronger for male drivers than for female drivers. Conclusion The higher risk of non-fatal MVC injuries in obese male drivers might result from their different body shape and fat distribution compared with obese female drivers. Our findings should be considered for obesity reduction, traffic safety evaluation and vehicle design for obese male drivers and provide testable hypotheses for future studies. PMID:21224830
Obesity and non-fatal motor vehicle crash injuries: sex difference effects.
Ma, X; Laud, P W; Pintar, F; Kim, J-E; Shih, A; Shen, W; Heymsfield, S B; Allison, D B; Zhu, S
2011-09-01
Obesity and motor vehicle crash (MVC) injuries are two parallel epidemics in the United States. An important unanswered question is whether there are sex differences in the associations between the presence of obesity and non-fatal MVC injuries. To further understand the association between obesity and non-fatal MVC injuries, particularly the sex differences in these relations. We examined this question by analyzing data from the 2003 to 2007 National Automotive Sampling System Crashworthiness Data System (NASS CDS). A total of 10,962 drivers who were aged 18 years or older and who survived frontal collision crashes were eligible for the study. Male drivers experienced a lower rate of overall non-fatal MVC injuries than did female drivers (38.1 versus 52.2%), but experienced a higher rate of severe injuries (0.7 versus 0.2%). After adjusting for change in velocity (ΔV) during the crashes, obese male drivers showed a much higher risk (logistic coefficients of body mass index (BMI) for moderate, serious and severe injury are 0.0766, 0.1470 and 0.1792, respectively; all P<0.05) of non-fatal injuries than did non-obese male drivers and these risks increased with injury severity. Non-fatal injury risks were not found to be increased in obese female drivers. The association between obesity and risk of non-fatal injury was much stronger for male drivers than for female drivers. The higher risk of non-fatal MVC injuries in obese male drivers might result from their different body shape and fat distribution compared with obese female drivers. Our findings should be considered for obesity reduction, traffic safety evaluation and vehicle design for obese male drivers and provide testable hypotheses for future studies.
Crash-related mortality and model year: are newer vehicles safer?
Ryb, Gabriel E; Dischinger, Patricia C; McGwin, Gerald; Griffin, Russell L
2011-01-01
The objective of this study was to determine whether occupants of newer vehicles experience a lower risk of crash-related mortality. The occurrence of death was studied in relation to vehicle model year (MY) among front seat vehicular occupants, age ≥ 16 captured in the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) between 2000 and 2008. The associations between death and other occupant, vehicular and crash characteristics were also explored. Multiple logistic regression models for the prediction of death were built with model year as the independent variable and other characteristics linked to death as covariates. Imputation was used for missing data; weighted data was used. A total of 70,314 cases representing 30,514,372 weighted cases were available for analysis. Death occurred in 0.6% of the weighted population. Death was linked to age>60, male gender, higher BMI, near lateral direction of impact, high delta v, rollover, ejection and vehicle mismatch, and negatively associated with seatbelt use and rear and far lateral direction of impact. Mortality decreased with later model year groups (MY<94 0.78%, MY 94-97 0.53%, MY 98-04 0.51% and MY 05-08 0.38%, p=<0.0001). After adjustment for confounders, MY 94-97, MY 98-04 and MY 05-08 showed decreased odds of death [OR 0.80 (0.69-0.94), 0.82 (0.70-0.97), and 0.67 (0.47-0.96), respectively] when compared to MY <94. Newer vehicles are associated with lower crash-related mortality. Their introduction into the vehicle fleet may explain, at least in part, the decrease in mortality rates in the past two decades.
Ivarsson, Johan; Poplin, Gerald; McMurry, Tim; Crandall, Jeff; Kerrigan, Jason
2015-12-01
Planar impacts with objects and other vehicles may increase the risk and severity of injury in rollover crashes. The current study compares the frequency of injury measures (MAIS 2+, 3+, and 4+; fatal; AIS 2+ head and cervical spine; and AIS 3+ head and thorax) as well as vehicle type distribution (passenger car, SUV, van, and light truck), crash kinematics, and occupant demographics between single vehicle single event rollovers (SV Pure) and multiple event rollovers to determine which types of multiple event rollovers can be pooled with SV Pure to study rollover induced occupant injury. Four different types of multiple event rollovers were defined: single and multi-vehicle crashes for which the rollover is the most severe event (SV Prim and MV Prim) and single and multi-vehicle crashes for which the rollover is not the most severe event (SV Non-Prim and MV Non-Prim). Information from real world crashes was obtained from the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the period from 1995 through 2011. Belted, contained or partially ejected, adult occupants in vehicles that completed 1-16 lateral quarter turns were assigned to one of the five rollover categories. The results showed that the frequency of injury in non-primary rollovers (SV Non-Prim and MV Non-Prim) involving no more than one roof inversion is substantially greater than in SV Pure, but that this disparity diminishes for crashes involving multiple inversions. It can further be concluded that for a given number of roof inversions, the distribution of injuries and crash characteristics in SV Pure and SV Prim crashes are sufficiently similar for these categories to be considered collectively for purposes of understanding etiologies and developing strategies for prevention. Copyright © 2015 Elsevier Ltd. All rights reserved.
The relationship between body weight and risk of death and serious injury in motor vehicle crashes.
Mock, Charles N; Grossman, David C; Kaufman, Robert P; Mack, Christopher D; Rivara, Frederick P
2002-03-01
We sought to investigate the effect of increased body weight on the risk of death and serious injury to occupants in motor vehicle crashes. We employed a retrospective cohort study design utilizing data from the National Automotive Sampling System, Crashworthiness Data System (CDS), 1993-1996. Subjects in the study included occupants involved in tow-away crashes of passenger cars, light trucks, vans and sport utility vehicles. Two outcomes were analyzed: death within 30 days of the crash and injury severity score (ISS). Two exposures were considered: occupant body weight and body mass index (BMI; kg/m2). Occupant weight was available on 27263 subjects (76%) in the CDS database. Mortality was 0.67%. Increased body weight was associated with increased risk of mortality and increased risk of severe injury. The odds ratio for death was 1.013 (95% CI: 1.007, 1.018) for each kilogram increase in body weight. The odds ratio for sustaining an injury with ISS > or = 9 was 1.008 (95% CI: 1.004, 1.011) for each kilogram increase in body weight. After adjustment for potentially confounding variables (age, gender, seatbelt use, seat position and vehicle curbweight), the significant relationship between occupant weight and mortality persisted. After adjustment, the relationship between occupant weight and ISS was present, although less marked. Similar trends were found when BMI was analyzed as the exposure. In conclusion, increased occupant body weight is associated with increased mortality in automobile crashes. This is probably due in part to increased co-morbid factors in the more overweight occupants. However, it is possibly also due to an increased severity of injury in these occupants. These findings may have implications for vehicle safety design, as well as for transport safety policy.
Effects of osteoporosis on AIS 3+ injury risk in motor-vehicle crashes.
Rupp, Jonathan D; Flannagan, Carol A C; Hoff, Carrie N; Cunningham, Rebecca M
2010-11-01
Older occupants in motor-vehicle crashes are more likely to experience injury than younger occupants. One possible reason for this is that increasing age is associated with increased prevalence of osteoporosis, which decreases bone strength. Crash-injury data were used with Bayes' Theorem to estimate the conditional probability of AIS 3+ skeletal injury given that an occupant is osteoporotic for the injury to the head, spine, thorax, lower extremities, and upper extremities. This requires the conditional probabilities of osteoporosis given AIS 3+ injury for each of the body regions, which were determined from analysis of the Crash Injury Research and Engineering Network database. It also requires information on probability of osteoporosis in the crash-involved population and the probabilities of AIS 3+ skeletal injury to different body regions in crashes. The latter probabilities were obtained from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database. The former was obtained by modeling the probability of osteoporosis in the US populations using data from the 2006 National Health Examination Nutrition Survey and applying this model to the estimate of the crash-involved population in NASS-CDS. To attempt to account for the effects of age on injury outcome that are independent of osteoporosis, only data from occupants who were 60 years of age or older were used in all analyses. Results indicate that the only body region that experiences a statistically significant change in fracture injury risk with osteoporosis is the spine, for which osteoporosis increases the risk of AIS 3+ fracture by 3.28 times, or from 0.41% to 1.34% (p<0.0001). This finding suggests that the increase in AIS 3+ injury risk with age for non-spine injuries is likely influenced by factors other than osteoporosis. 2010 Elsevier Ltd. All rights reserved.
1976-07-01
1965 Summary, Pg. 11 21. 6/14/65, DC-8, , Santiago , Chile Left main landing gear brakes were locked on touchdown causing tire blowouts and a small fire... concentration of nine percent will prevent an explosion such as hat which occurred under similar ex- ternal fire test conditions in an tudnerted fuel tank. These...the inert concentration in the tanks was lost, providing more time for safe evacuation. Liquid nitrogen fuel tank inerting technology is presently
Energy and technology review: Engineering modeling
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cabayan, H.S.; Goudreau, G.L.; Ziolkowski, R.W.
1986-10-01
This report presents information concerning: Modeling Canonical Problems in Electromagnetic Coupling Through Apertures; Finite-Element Codes for Computing Electrostatic Fields; Finite-Element Modeling of Electromagnetic Phenomena; Modeling Microwave-Pulse Compression in a Resonant Cavity; Lagrangian Finite-Element Analysis of Penetration Mechanics; Crashworthiness Engineering; Computer Modeling of Metal-Forming Processes; Thermal-Mechanical Modeling of Tungsten Arc Welding; Modeling Air Breakdown Induced by Electromagnetic Fields; Iterative Techniques for Solving Boltzmann's Equations for p-Type Semiconductors; Semiconductor Modeling; and Improved Numerical-Solution Techniques in Large-Scale Stress Analysis.
Failure mechanisms in energy-absorbing composite structures
NASA Astrophysics Data System (ADS)
Johnson, Alastair F.; David, Matthew
2010-11-01
Quasi-static tests are described for determination of the energy-absorption properties of composite crash energy-absorbing segment elements under axial loads. Detailed computer tomography scans of failed specimens were used to identify local compression crush failure mechanisms at the crush front. These mechanisms are important for selecting composite materials for energy-absorbing structures, such as helicopter and aircraft sub-floors. Finite element models of the failure processes are described that could be the basis for materials selection and future design procedures for crashworthy structures.
Safety Passage in the Flying Canoes
NASA Technical Reports Server (NTRS)
1984-01-01
Jungle Aviation and Radio Service (JAARS) delivers missionaries to remote outposts under sometimes hazardous flying conditions. A serious accident led JAARS' to initiate a crash survivability research program based on NASA technology. In 1978, JAARS sought help from Langley Research Center and was invited to participate in Langley's crashworthiness program. With assistance from Langley, JAARS developed an impact absorbing aircraft seat designed to minimize crash injury. The seat design is available to all missionary aircraft and JAARS is offering it for commercial manufacture.
Structures and Dynamics Division research and technology plans, FY 1982
NASA Technical Reports Server (NTRS)
Bales, K. S.
1982-01-01
Computational devices to improve efficiency for structural calculations are assessed. The potential of large arrays of microprocessors operating in parallel for finite element analysis is defined, and the impact of specialized computer hardware on static, dynamic, thermal analysis in the optimization of structural analysis and design calculations is determined. General aviation aircraft crashworthiness and occupant survivability is also considered. Mechanics technology required for design coefficient, fault tolerant advanced composite aircraft components subject to combined loads, impact, postbuckling effects and local discontinuities are developed.
Microstructure and mechanical properties of sheep horn.
Zhu, Bing; Zhang, Ming; Zhao, Jian
2016-07-01
The sheep horn presents outstanding mechanical properties of impact resistance and energy absorption, which suits the need of the vehicle bumper design, but the mechanism behind this phenomenon is less investigated. The microstructure and mechanical properties of the sheep horn of Small Tailed Han Sheep (Ovis aries) living in northeast China were investigated in this article. The effect of sampling position and orientation of the sheep horn sheath on mechanical properties were researched by tensile and compression tests. Meanwhile, the surface morphology and microstructure of the sheep horn were observed using scanning electron microscopy (SEM). The formation mechanism of the mechanical properties of the sheep horn was investigated by biological coupling analysis. The analytical results indicated that the outstanding mechanical properties of the sheep horn are determined by configuration, structure, surface morphology and material coupling elements. These biological coupling elements make the sheep horn possess super characteristics of crashworthiness and energy absorption through the internal coupling mechanism. We suppose that these findings would make a difference in vehicle bumper design. Microsc. Res. Tech. 79:664-674, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Predicting injury risk with "New Car Assessment Program" crashworthiness ratings.
Jones, I S; Whitfield, R A
1988-12-01
The relationship between crashworthiness ratings produced by the National Highway Traffic Safety Administration's (NHTSA's) New Car Assessment Program (NCAP) and the risk of incapacitating injury or death for drivers who are involved in single-car, fixed-object, frontal collisions was examined. The results are based on 6,405 such crashes from the Motor Vehicle Traffic Accident file of the Texas Department of Highways and Public Transportation. The risk of injury was modeled using logistic regression taking into account the NCAP test results for each individual model of car and the intervening effects of car mass, age of the driver, restraint use, and crash severity. Three measures of anthropometric dummy response, Head Injury Criterion (HIC), Chest Deceleration (CD), and femur load were used to indicate vehicle crash test performance. The results show that there is a significant relationship between the results of the NCAP tests and the risk of serious injury or death in actual single-car frontal accidents. In terms of overall injury, chest deceleration was a better predictor than the Head Injury Criterion. For restrained drivers, crash severity, driver age, and chest deceleration were significant parameters for predicting risk of serious injury or death; the risk of injury decreased as chest deceleration decreased. The results were similar for unrestrained drivers although vehicle mass and femur load were also significant factors in the model. The risk of overall injury decreased as chest deceleration decreased but appeared to decrease as femur load increased.
Analysis of hot forming of a sheet metal component made of advanced high strength steel
NASA Astrophysics Data System (ADS)
Demirkaya, Sinem; Darendeliler, Haluk; Gökler, Mustafa İlhan; Ayhaner, Murat
2013-05-01
To provide reduction in weight while maintaining crashworthiness and to decrease the fuel consumption of vehicles, thinner components made of Advanced High Strength Steels (AHSS) are being increasingly used in automotive industry. However, AHSS cannot be formed easily at the room temperature (i.e. cold forming). The alternative process involves heating, hot forming and subsequent quenching. A-pillar upper reinforcement of a vehicle is currently being produced by cold forming of DP600 steel sheet with a thickness of 1.8 mm. In this study, the possible decrease in the thickness of this particular part by using 22MnB5 as appropriate AHSS material and applying this alternative process has been studied. The proposed process involves deep drawing, trimming, heating, sizing, cooling and piercing operations. Both the current production process and the proposed process are analyzed by the finite element method. The die geometry, blank holding forces and the design of the cooling channels for the cooling process are determined numerically. It is shown that the particular part made of 22MnB5 steel sheet with a thickness of 1.2 mm can be successfully produced by applying the proposed process sequence and can be used without sacrificing the crashworthiness. With the use of the 22MnB5 steel with a thickness of 1.2 mm instead of DP600 sheet metal with a thickness of 1.8 mm, the weight is reduced by approximately 33%.
A new method for predicting crashworthiness.
Council, F M; Stewart, J R; Cox, C L
1997-01-01
Consumer information concerning the predicted 'safeness' of a new car model is based on the results of crash tests. Unfortunately, because it allows comparisons only within size/weight groups, the information is somewhat incompatible with the normal car-purchase decision process since consumers often consider cars within different groups. In addition, based on past research, the association of the crash-test information with real-world crash outcomes is, at best, somewhat limited. The goal of this study was to explore a methodology for improving this information, a methodology which incorporates not only the crash-test information, but also information concerning real-world occupant injury experience in prior crashes involving similar vehicles ('clones'). The clone information included both driver injury severity in past clone crashes from the North Carolina accident file and various indicators of relative driver injury in clones extracted from published insurance-related data from the Highway Loss Data Institute (HLDI). Final models developed included both measures of the Head Index Criteria (HIC) from the crash test and some measure of clone performances as significant predictors. While the North Carolina clone data is intuitively 'cleaner' in that it describes injury level per crash rather than per insured year, the medical claims indices from the HLDI data consistently were shown to be the stronger predictors. Future research will need to look at ways of better combining the crash-test variables and of possible modifications to the HLDI indices. In general, the analyses generated encouraging results that appear to point to possible improvements in the crashworthiness information.
Multiscale Analysis of Open-Cell Aluminum Foam for Impact Energy Absorption
NASA Astrophysics Data System (ADS)
Kim, Ji Hoon; Kim, Daeyong; Lee, Myoung-Gyu; Lee, Jong Kook
2016-09-01
The energy-absorbing characteristics of crash members in automotive collision play an important role in controlling the amount of damage to the passenger compartment. Aluminum foams have high strength-to-weight ratio and high deformability, thus good crashworthiness is expected while maintaining or even saving weights when foams are implemented in crash members. In order to investigate the effect of the open-cell aluminum foam fillers on impact performance and weight saving, a multiscale framework for evaluating the crashworthiness of aluminum foam-filled members is used. To circumvent the difficulties of mechanical tests on foams, a micromechanical model of the aluminum foam is constructed using the x-ray micro tomography and virtual tests are conducted for the micromechanical model to characterize the behavior of the foam. In the macroscale, the aluminum foam is represented by the crushable foam constitutive model, which is then incorporated into the impact test simulation of the foam-filled crash member. The multiscale foam-filled crash member model was validated for the high-speed impact test, which confirms that the material model characterized by the micromechanical approach represents the behavior of the open-cell foam under impact loading well. Finally, the crash member design for maximizing the energy absorption is discussed by investigating various designs from the foam-only structure to the hollow tube structure. It was found that the foam structure absorbs more energy than the hollow tube or foam-filled structure with the same weight.
The influence of triggers geometry upon the stiffness of cylindrical thin walled tubes
NASA Astrophysics Data System (ADS)
Soica, Adrian; Radu, Gheorghe N.
2014-06-01
Today's automobile manufacturers are increasingly using lightweight materials to reduce weight; these include plastics, composites, aluminium, magnesium alloys, and also new types of high strength steels. Many of these materials have limited strength or ductility, therefore in many cases the rupture being serious consequences during crashes, underscore Picketta et al. in their studies. Automotive structures must deform plastically in a short period of time, a few milliseconds, to absorb the crash energy in a controllable manner. It must be light and enable economically mass-production [1]. FE models rapidly gained acceptance among engineers. Many other factors facilitated the development of vehicle models by shell finite elements since most of the geometry of the structural surfaces was already on computer graphic files. Kee Poong Kim and Hoon Huh emphasize that the crashworthiness of each vehicle part needs to be evaluated at the initial stage of design for good performance of an assembled vehicle. As the dynamic behaviour of structural members is different from the static one, the crashworthiness of the vehicle structures has to be assessed by impact analysis. The paper analyzes the influence of trigger geometry upon the compression of thin-walled cylindrical tubes. Simulations performed on a simple model showed the dependence between triggers area and deformation times as well as the maximum deformations obtained for various speeds at which the simulations ware carried out. Likewise, the geometry of trigger leads to different results.
NASA Astrophysics Data System (ADS)
Kh. Beheshti, Hamid
This study is focusing on the application of foam materials in aviation. These materials are being used for acoustic purposes, as padding in the finished interior panels of the aircraft, and as seat cushions. Foams are mostly used in seating applications. Since seat cushion is directly interacting with the body of occupant, it has to be ergonomically comfortable beside of absorbing the energy during the impact. All the seats and seat cushions have to pass regulations defined by Federal Aviation Administration (FAA). In fact, all airplane companies are required to certify the subcomponents of aircrafts before installing them on the main structure, fuselage. Current Federal Aviation Administration Regulations require a dynamic sled test of the entire seat system for certifying the seat cushions. This dynamic testing is required also for replacing the deteriorated cushions with new cushions. This involves a costly and time-consuming certification process. AGATE group has suggested a procedure based on quasi-static testing in order to certify new seat cushions without conducting full-scale dynamic sled testing. AGATE subcomponent methodology involves static tests of the energy-absorbing foam cushions and design validation by conducting a full-scale dynamic seat test. Microscopic and macroscopic studies are necessary to provide a complete understanding about performance of foams during the crash. Much investigation has been done by different sources to obtain the reliable modeling in terms of demonstration of mechanical behavior of foams. However, rate sensitivity of foams needs more attention. A mathematical hybrid dynamic model for the cushion underneath of the human body will be taken into consideration in this research. Analytical and finite element codes such as MADYMO and LS-DYNA codes have the potential to greatly speed up the crashworthy design process, to help certify seats and aircraft to dynamic crash loads, to predict seat and occupant response to impact with the probability of injury, and to evaluate numerous crash scenarios not economically feasible with full-scale crash testing. Therefore, these codes are being used to find the accurate response of spinal load during the impact of model including human body, seat cushion and seat under different acceleration pulses. (Abstract shortened by UMI.)
Tang, Youming; Cao, Libo; Kan, Steven
2014-05-08
To examine the damage location distribution of five main body region injuries of maximum abbreviated injury score (MAIS) 3-6 injured occupants for nearside struck vehicle in front-to-side impact crashes. MAIS 3-6 injured occupants information was extracted from the US-National Automotive Sampling System/Crashworthiness Data System in the year 2007; it included the head/face/neck, chest, pelvis, upper extremity and lower extremity. Struck vehicle collision damage was classified in a three-dimensional system according to the J224 Collision Deformation Classification of SAE Surface Vehicle Standard. Nearside occupants seated directly adjacent to the struck side of the vehicle with MAIS 3-6 injured, in light truck vehicles-passenger cars (LTV-PC) side impact crashes. Distribution of MAIS 3-6 injured occupants by body regions and specific location of damage (lateral direction, horizontal direction and vertical direction) were examined. Injury risk ratio was also assessed. The lateral crush zone contributed to MAIS 3-6 injured occupants (n=705) and 50th centile injury risks when extended into zone 3. When the crush extended to zone 4, the injury risk ratio of MAIS 3-6 injured occupants approached 81%. The horizontal crush zones contributing to the highest injury risk ratio of MAIS 3-6 occupants were zones 'D' and 'Y', and the injury risk ratios were 25.4% and 36.9%, respectively. In contrast, the lowest injury risk ratio was 5.67% caused by zone 'B'. The vertical crush zone which contributed to the highest injury risk ratio of MAIS 3-6 occupants was zone 'E', whose injury risk ratio was 58%. In contrast, the lowest injury risk ratio was 0.14% caused by zone 'G+M'. The highest injury risk ratio of MAIS 3-6 injured occupants caused by crush intrusion between 40 and 60 cm in LTV-PC nearside impact collisions and the damage region of the struck vehicle was in the zones 'E' and 'Y'.
Obesity and vehicle type as risk factors for injury caused by motor vehicle collision.
Donnelly, John P; Griffin, Russell Lee; Sathiakumar, Nalini; McGwin, Gerald
2014-04-01
This study sought to describe variations in the risk of motor vehicle collision (MVC) injury and death by occupant body mass index (BMI) class and vehicle type. We hypothesized that the relationship between BMI and the risk of MVC injury or mortality would be modified by vehicle type. This is a retrospective cohort study of occupants involved in MVCs using data from the Crash Injury Research and Engineering Network and the National Automotive Sampling System Crashworthiness Data System. Occupants were grouped based on vehicle body style (passenger car, sport utility vehicle, or light truck) and vehicle size (compact or normal, corresponding to below- or above-average curb weight). The relationship between occupant BMI class (underweight, normal weight, overweight, or obese) and risk of injury or mortality was examined for each vehicle type. Odds ratios (ORs) adjusted for various occupant and collision characteristics were estimated. Of an estimated 44 million occupants of MVCs sampled from 2000 to 2009, 37.1% sustained an injury. We limited our analysis to injuries achieving an Abbreviated Injury Scale (AIS) score of 2 or more severe, totaling 17 million injuries. Occupants differed substantially in terms of demographic and collision characteristics. After adjustment for confounding factors, we found that obesity was a risk factor for mortality caused by MVC (OR, 1.6; 95% confidence interval [CI], 1.2-2.0). When stratified by vehicle type, we found that obesity was a risk factor for mortality in larger vehicles, including any-sized light trucks (OR, 2.1; 95% CI, 1.3-3.5), normal-sized passenger cars (OR, 1.6; 95% CI, 1.1-2.3), and normal-sized sports utility vehicles or vans (OR, 2.0; 95% CI, 1.0-3.8). Being overweight was a risk factor in any-sized light trucks (OR, 1.5; 95% CI, 1.1-2.1). We identified a significant interaction between occupant BMI class and vehicle type in terms of MVC-related mortality risk. Both factors should be taken into account when considering occupant safety, and additional study is needed to determine underlying causes of the observed relationships. Epidemiologic study, level III.
Tencer, Allan F; Kaufman, Robert; Mack, Christopher; Mock, Charles
2005-03-01
The goal of this study was to identify variables related to vehicle design which are associated with pelvic and thoracic accelerations as measured by the driver's (near side) crash dummy during new car assessment program (NCAP) testing of motor vehicles. Vehicle specific parameters were analyzed using NCAP side impact test results. Data from national automotive sampling system, crashworthiness data system (NASS-CDS) and crash injury research and engineering network (CIREN) (both National Highway Traffic Safety Administration (NHTSA) injury databases) were assessed to confirm NCAP test observations. In addition, door armrest stiffness measurements were performed using a mechanical tester on a sample of 40 vehicles. NCAP data showed that of 10 variables tested using multiple linear regression, vehicle weight and door crush correlated with pelvic acceleration of the driver's crash dummy (overall, r2=0.58, p=0.002, n=165). For thoracic trauma index (TTI) vehicle weight and peak door velocity correlated, significantly (overall, r2=0.41, p=0.03, n=165). Mean TTI was 63.7 g with no side airbag (n=108) and 55.6 g with a thoracic side airbag (n=54), p=0.01. The mean vehicle weight and door crush between airbag and no airbag groups were not significantly different. NASS-CDS data demonstrated a direct relationship between increased door crush and increased abbreviated injury score (AIS). CIREN data showed that occupants who sustained pelvic injuries had a median AIS of 3 with 24.9 cm of door crush, with abdominal injuries, a median AIS of 3 and 30 cm of crush, and with thoracic injuries, a median AIS of 4 and 34 cm of door crush. In addition, the frequency of bilateral pelvic injuries was significantly higher for subjects in CIREN crashes who were in a vehicle with a center console, but only if door intrusion was greater than 15 cm. This information may be useful in design of vehicles with greater protection in side impact crashes.
Energy absorption of composite material and structure
NASA Technical Reports Server (NTRS)
Farley, Gary L.
1987-01-01
Results are presented from a joint research program on helicopter crashworthiness conducted by the U.S. Army Aerostructures Directorate and NASA Langley. Through the ongoing research program an in-depth understanding has been developed on the cause/effect relationships between material and architectural variables and the energy-absorption capability of composite material and structure. Composite materials were found to be efficient energy absorbers. Graphite/epoxy subfloor structures were more efficient energy absorbers than comparable structures fabricated from Kevlar or aluminum. An accurate method of predicting the energy-absorption capability of beams was developed.
Development of a Crashworthy Seat for Commuter Aircraft
1990-09-01
the seat base frame by pivot arms at rollers, the seat pan moves downward. The force each side of the front of the pan. A wire bending to maintain the... wire bending action is constant FA device linked the rear corners of the seat pan and may be altered by the type and size of wires to the base frame...wires In ence with sh-xi’lar devices provided a rational the wire bending mechanism. (c) the angle of the basis with which to evaluate these devices
Energy absorption capabilities of complex thin walled structures
NASA Astrophysics Data System (ADS)
Tarlochan, F.; AlKhatib, Sami
2017-10-01
Thin walled structures have been used in the area of energy absorption during an event of a crash. A lot of work has been done on tubular structures. Due to limitation of manufacturing process, complex geometries were dismissed as potential solutions. With the advancement in metal additive manufacturing, complex geometries can be realized. As a motivation, the objective of this study is to investigate computationally the crash performance of complex tubular structures. Five designs were considered. In was found that complex geometries have better crashworthiness performance than standard tubular structures used currently.
1982-04-02
General S130 Eclipse computer. 2.2.3 Photographic Coverage Each crash test was recorded on 16 mm color film by four W cameras. The event was filmed at...rotate further nose-up until impact. Unfortunately, all cameras had either run out of film or had been turned off prior to impact so that there is no...record of impact angle or crash events. From visual observations at the time, the impact angle seemed to be nearly 90* nose-up. What film exists
NASA general aviation crashworthiness seat development
NASA Technical Reports Server (NTRS)
Fasanella, E. L.; Alfaro-Bou, E.
1979-01-01
Three load limiting seat concepts for general aviation aircraft designed to lower the deceleration of the occupant in the event of a crash were sled tested and evaluated with reference to a standard seat. Dummy pelvis accelerations were reduced up to 50 percent with one of the concepts. Computer program MSOMLA (Modified Seat Occupant Model for Light Aircraft) was used to simulate the behavior of a dummy passenger in a NASA full-scale crash test of a twin engine light aircraft. A computer graphics package MANPLOT was developed to pictorially represent the occupant and seat motion.
Crash Certification by Analysis - Are We There Yet?
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Fasanella, Edwin L.; Lyle, Karen H.
2006-01-01
This paper addresses the issue of crash certification by analysis. This broad topic encompasses many ancillary issues including model validation procedures, uncertainty in test data and analysis models, probabilistic techniques for test-analysis correlation, verification of the mathematical formulation, and establishment of appropriate qualification requirements. This paper will focus on certification requirements for crashworthiness of military helicopters; capabilities of the current analysis codes used for crash modeling and simulation, including some examples of simulations from the literature to illustrate the current approach to model validation; and future directions needed to achieve "crash certification by analysis."
Optimisation study of a vehicle bumper subsystem with fuzzy parameters
NASA Astrophysics Data System (ADS)
Farkas, L.; Moens, D.; Donders, S.; Vandepitte, D.
2012-10-01
This paper deals with the design and optimisation for crashworthiness of a vehicle bumper subsystem, which is a key scenario for vehicle component design. The automotive manufacturers and suppliers have to find optimal design solutions for such subsystems that comply with the conflicting requirements of the regulatory bodies regarding functional performance (safety and repairability) and regarding the environmental impact (mass). For the bumper design challenge, an integrated methodology for multi-attribute design engineering of mechanical structures is set up. The integrated process captures the various tasks that are usually performed manually, this way facilitating the automated design iterations for optimisation. Subsequently, an optimisation process is applied that takes the effect of parametric uncertainties into account, such that the system level of failure possibility is acceptable. This optimisation process is referred to as possibility-based design optimisation and integrates the fuzzy FE analysis applied for the uncertainty treatment in crash simulations. This process is the counterpart of the reliability-based design optimisation used in a probabilistic context with statistically defined parameters (variabilities).
NASA Astrophysics Data System (ADS)
Stronge, W. J.
2004-03-01
Impact mechanics is concerned with the reaction forces that develop during a collision and the dynamic response of structures to these reaction forces. The subject has a wide range of engineering applications, from designing sports equipment to improving the crashworthiness of automobiles. This book develops several different methodologies for analysing collisions between structures. These range from rigid body theory for structures that are stiff and compact, to vibration and wave analyses for flexible structures. The emphasis is on low-speed impact where damage is local to the small region of contact between the colliding bodies. The analytical methods presented give results that are more robust or less sensitive to initial conditions than have been achieved hitherto. As a text, Impact Mechanics builds upon foundation courses in dynamics and strength of materials. It includes numerous industrially relevant examples and end-of-chapter homework problems drawn from industry and sports. Practising engineers will also find the methods presented in this book useful in calculating the response of a mechanical system to impact.
Mo, Fuhao; Zhao, Siqi; Yu, Chuanhui; Duan, Shuyong
2018-01-01
The car front bumper system needs to meet the requirements of both pedestrian safety and low-speed impact which are somewhat contradicting. This study aims to design a new kind of modular self-adaptive energy absorber of the front bumper system which can balance the two performances. The X-shaped energy-absorbing structure was proposed which can enhance the energy absorption capacity during impact by changing its deformation mode based on the amount of external collision energy. Then, finite element simulations with a realistic vehicle bumper system are performed to demonstrate its crashworthiness in comparison with the traditional foam energy absorber, which presents a significant improvement of the two performances. Furthermore, the structural parameters of the X-shaped energy-absorbing structure including thickness (t u), side arc radius (R), and clamping boost beam thickness (t b) are analyzed using a full factorial method, and a multiobjective optimization is implemented regarding evaluation indexes of both pedestrian safety and low-speed impact. The optimal parameters are then verified, and the feasibility of the optimal results is confirmed. In conclusion, the new X-shaped energy absorber can meet both pedestrian safety and low-speed impact requirements well by altering the main deformation modes according to different impact energy levels. PMID:29581728
Mo, Fuhao; Zhao, Siqi; Yu, Chuanhui; Xiao, Zhi; Duan, Shuyong
2018-01-01
The car front bumper system needs to meet the requirements of both pedestrian safety and low-speed impact which are somewhat contradicting. This study aims to design a new kind of modular self-adaptive energy absorber of the front bumper system which can balance the two performances. The X-shaped energy-absorbing structure was proposed which can enhance the energy absorption capacity during impact by changing its deformation mode based on the amount of external collision energy. Then, finite element simulations with a realistic vehicle bumper system are performed to demonstrate its crashworthiness in comparison with the traditional foam energy absorber, which presents a significant improvement of the two performances. Furthermore, the structural parameters of the X-shaped energy-absorbing structure including thickness ( t u ), side arc radius ( R ), and clamping boost beam thickness ( t b ) are analyzed using a full factorial method, and a multiobjective optimization is implemented regarding evaluation indexes of both pedestrian safety and low-speed impact. The optimal parameters are then verified, and the feasibility of the optimal results is confirmed. In conclusion, the new X-shaped energy absorber can meet both pedestrian safety and low-speed impact requirements well by altering the main deformation modes according to different impact energy levels.
Detailed Post-Soft Impact Progressive Damage Assessment for Hybrid Structure Jet Engines
NASA Technical Reports Server (NTRS)
Siddens, Aaron; Bayandor, Javid; Celestina, Mark L.
2014-01-01
Currently, certification of engine designs for resistance to bird strike is reliant on physical tests. Predictive modeling of engine structural damage has mostly been limited to evaluation of individual forward section components, such as fan blades within a fixed frame of reference, to direct impact with a bird. Such models must be extended to include interactions among engine components under operating conditions to evaluate the full extent of engine damage. This paper presents the results of a study aim to develop a methodology for evaluating bird strike damage in advanced propulsion systems incorporating hybrid composite/metal structures. The initial degradation and failure of individual fan blades struck by a bird were investigated. Subsequent damage to other fan blades and engine components due to resultant violent fan assembly vibrations and fragmentation was further evaluated. Various modeling parameters for the bird and engine components were investigated to determine guidelines for accurately capturing initial damage and progressive failure of engine components. Then, a novel hybrid structure modeling approach was investigated and incorporated into the crashworthiness methodology. Such a tool is invaluable to the process of design, development, and certification of future advanced propulsion systems.
The new car assessment program: does it predict the relative safety of vehicles in actual crashes?
Nirula, Ram; Mock, Charles N; Nathens, Avery B; Grossman, David C
2004-10-01
Federal motor vehicle safety standards are based on crash test dummy analyses that estimate the relative risk of traumatic brain injury (TBI) and severe thoracic injury (STI) by quantifying head (Head Injury Criterion [HIC]) and chest (Chest Gravity Score [CGS]) acceleration. The New Car Assessment Program (NCAP) combines these probabilities to yield the vehicle's five-star rating. The validity of the NCAP system as it relates to an actual motor vehicle crash (MVC) remains undetermined. We therefore sought to determine whether HIC and CGS accurately predict TBI and STI in actual crashes, and compared the NCAP five-star rating system to the rates of TBI and/or STI in actual MVCs. We analyzed frontal crashes with restrained drivers from the 1994 to 1998 National Automotive Sampling System. The relationship of HIC and CGS to the probabilities of TBI and STI derived from crash tests were respectively compared with the HIC-TBI and CGS-STI risk relationships observed in actual crashes while controlling for covariates. Receiver operating characteristic curves determined the sensitivity and specificity of HIC and CGS as predictors of TBI and STI, respectively. Estimates of the likelihood of TBI and/or STI (in actual MVCs) were compared with the expected probabilities of TBI and STI (determined by crash test analysis), as they relate to NCAP ratings. The crash tests overestimate TBI likelihood at HIC scores >800 and underestimate it at scores <500. STI likelihood is overestimated when CGS exceeds 40 g. Receiver operating characteristic curves demonstrated poor sensitivity and specificity of HIC and CGS in predicting injury. The actual MVC injury probability estimates did not vary between vehicles of different NCAP rating. HIC and CGS are poor predictors of TBI and STI in actual MVCs. The NCAP five-star rating system is unable to differentiate vehicles of varying crashworthiness in actual MVCs. More sensitive parameters need to be developed and incorporated into vehicle crash safety testing to provide consumers and automotive manufacturers with useful tools with which to measure vehicle safety.
DOE Office of Scientific and Technical Information (OSTI.GOV)
DiNapoli, N.; Fitzpatrick, M.; Strother, C.
1977-11-01
Phase I identified trends leading to the desired national social goals of the mid-1980's in vehicle crashworthiness, crash avoidance, damageability, pedestrian safety, fuel economy, emissions and cost, and characterized an RSV to satisfy them. In Phase II an RSV prototype was designed, developed and tested to demonstrate the feasibility of meeting these goals simultaneously. Although further refinement is necessary to assure operational validity, in all categories the results meet or exceed the most advanced performance specified by The Presidential Task Force on Motor Vehicle Goals beyond 1980.
Characterising ductility of 6xxx-series aluminium sheet alloys at combined loading conditions
NASA Astrophysics Data System (ADS)
Henn, Philipp; Liewald, Mathias; Sindel, Manfred
2017-10-01
This paper presents a new approach to characterise material ductility when combined, three dimensional loading conditions occurring during vehicle crash are applied. So called "axial crush test" of closed hat sections is simplified by reducing it down to a two-dimensional testing procedure. This newly developed edge-compression test (ECT) provides the opportunity to investigate a defined characteristic axial folding behaviour of a profile edge. The potential to quantify and to differentiate crashworthiness of material by use of new edge-compression test is investigated by carrying out experimental studies with two different 6xxx-aluminium sheet alloys.
NASA Astrophysics Data System (ADS)
Couque, Hervé
2012-08-01
The DYMAT International Conference is a "compelling scientific event" for engineers and scientists working in the dynamic behaviour of materials field. Since 1983, DYMAT has been organizing a five days single sessions of oral presentations and poster exhibitions with proceedings available at the beginning of the conferences. Well-known for its scientific interest, the triennially DYMAT International Conferences are the platform to present the most recent scientific achievements on dynamic behaviour of materials relevant to crashworthiness in all types of transports; terminal ballistics related to defence and shielding of satellites, of turbine; blast effects due to industrial explosions, terrorist attacks; material processing such as high speed machining.
Key issues in application of composites to transport aircraft
NASA Technical Reports Server (NTRS)
Stone, M.
1978-01-01
The application of composite materials to transport aircraft was identified and reviewed including the major contributing disciplines of design, manufacturing, and processing. Factors considered include: crashworthiness considerations (structural integrity, postcrash fires, and structural fusing), electrical/avionics subsystems integration, lightning, and P-static protection design; manufacturing development, evaluation, selection, and refining of tooling and curing procedures; and major joint design considerations. Development of the DC-10 rudder, DC-10 vertical stabilizer, and the DC-9 wing study project was reviewed. The Federal Aviation Administration interface and the effect on component design of compliance with Federal Aviation Regulation 25 Composite Guidelines are discussed.
NASA Subsonic Rotary Wing Project - Structures and Materials Discipline
NASA Technical Reports Server (NTRS)
Halbig, Michael C.; Johnson, Susan M.
2008-01-01
The Structures & Materials Discipline within the NASA Subsonic Rotary Wing Project is focused on developing rotorcraft technologies. The technologies being developed are within the task areas of: 5.1.1 Life Prediction Methods for Engine Structures & Components 5.1.2 Erosion Resistant Coatings for Improved Turbine Blade Life 5.2.1 Crashworthiness 5.2.2 Methods for Prediction of Fatigue Damage & Self Healing 5.3.1 Propulsion High Temperature Materials 5.3.2 Lightweight Structures and Noise Integration The presentation will discuss rotorcraft specific technical challenges and needs as well as details of the work being conducted in the six task areas.
Analysis of Crushing Response of Composite Crashworthy Structures
NASA Astrophysics Data System (ADS)
David, Matthew; Johnson, Alastair F.; Voggenreiter, H.
2013-10-01
The paper describes quasi-static and dynamic tests to characterise the energy absorption properties of polymer composite crash energy absorbing segment elements under axial loads. Detailed computer tomography scans of failed specimens are used to identify local compression crush failure mechanisms at the crush front. The varied crushing morphology between the compression strain rates identified in this paper is observed to be due to the differences in the response modes and mechanical properties of the strain dependent epoxy matrix. The importance of understanding the role of strain rate effects in composite crash energy absorbing structures is highlighted in this paper.
Light aircraft crash safety program
NASA Technical Reports Server (NTRS)
Thomson, R. G.; Hayduk, R. J.
1974-01-01
NASA is embarked upon research and development tasks aimed at providing the general aviation industry with a reliable crashworthy airframe design technology. The goals of the NASA program are: reliable analytical techniques for predicting the nonlinear behavior of structures; significant design improvements of airframes; and simulated full-scale crash test data. The analytical tools will include both simplified procedures for estimating energy absorption characteristics and more complex computer programs for analysis of general airframe structures under crash loading conditions. The analytical techniques being developed both in-house and under contract are described, and a comparison of some analytical predictions with experimental results is shown.
Emergency Medical Service (EMS): Rotorcraft Technology Workshop
NASA Technical Reports Server (NTRS)
Bauchspies, J. S.; Adams, R. J.
1981-01-01
A lead organization on the national level should be designated to establish concepts, locations, and the number of shock trauma air medical services. Medical specialists desire a vehicle which incorporates advances in medical technology trends in health care. Key technology needs for the emergency medical services helicopter of the future include the riding quality of fixed wing aircraft (reduced noise and vibration), no tail rotor, small rotor, small rotor diameter, improved visibility, crashworthy vehicle, IFR capability, more affordability high reliability, fuel efficient, and specialized cabins to hold medical/diagnostic and communications equipment. Approaches to a national emergency medical service are discussed.
Zhu, Shankuan; Kim, Jong-Eun; Ma, Xiaoguang; Shih, Alan; Laud, Purushottam W; Pintar, Frank; Shen, Wei; Heymsfield, Steven B; Allison, David B
2010-03-30
Men tend to have more upper body mass and fat than women, a physical characteristic that may predispose them to severe motor vehicle crash (MVC) injuries, particularly in certain body regions. This study examined MVC-related regional body injury and its association with the presence of driver obesity using both real-world data and computer crash simulation. Real-world data were from the 2001 to 2005 National Automotive Sampling System Crashworthiness Data System. A total of 10,941 drivers who were aged 18 years or older involved in frontal collision crashes were eligible for the study. Sex-specific logistic regression models were developed to analyze the associations between MVC injury and the presence of driver obesity. In order to confirm the findings from real-world data, computer models of obese subjects were constructed and crash simulations were performed. According to real-world data, obese men had a substantially higher risk of injury, especially serious injury, to the upper body regions including head, face, thorax, and spine than normal weight men (all p<0.05). A U-shaped relation was found between body mass index (BMI) and serious injury in the abdominal region for both men and women (p<0.05 for both BMI and BMI(2)). In the high-BMI range, men were more likely to be seriously injured than were women for all body regions except the extremities and abdominal region (all p<0.05 for interaction between BMI and sex). The findings from the computer simulation were generally consistent with the real-world results in the present study. Obese men endured a much higher risk of injury to upper body regions during MVCs. This higher risk may be attributed to differences in body shape, fat distribution, and center of gravity between obese and normal-weight subjects, and between men and women. Please see later in the article for the Editors' Summary.
Zhu, Shankuan; Kim, Jong-Eun; Ma, Xiaoguang; Shih, Alan; Laud, Purushottam W.; Pintar, Frank; Shen, Wei; Heymsfield, Steven B.; Allison, David B.
2010-01-01
Background Men tend to have more upper body mass and fat than women, a physical characteristic that may predispose them to severe motor vehicle crash (MVC) injuries, particularly in certain body regions. This study examined MVC-related regional body injury and its association with the presence of driver obesity using both real-world data and computer crash simulation. Methods and Findings Real-world data were from the 2001 to 2005 National Automotive Sampling System Crashworthiness Data System. A total of 10,941 drivers who were aged 18 years or older involved in frontal collision crashes were eligible for the study. Sex-specific logistic regression models were developed to analyze the associations between MVC injury and the presence of driver obesity. In order to confirm the findings from real-world data, computer models of obese subjects were constructed and crash simulations were performed. According to real-world data, obese men had a substantially higher risk of injury, especially serious injury, to the upper body regions including head, face, thorax, and spine than normal weight men (all p<0.05). A U-shaped relation was found between body mass index (BMI) and serious injury in the abdominal region for both men and women (p<0.05 for both BMI and BMI2). In the high-BMI range, men were more likely to be seriously injured than were women for all body regions except the extremities and abdominal region (all p<0.05 for interaction between BMI and sex). The findings from the computer simulation were generally consistent with the real-world results in the present study. Conclusions Obese men endured a much higher risk of injury to upper body regions during MVCs. This higher risk may be attributed to differences in body shape, fat distribution, and center of gravity between obese and normal-weight subjects, and between men and women. Please see later in the article for the Editors' Summary PMID:20361024
Mechanical Properties and Microstructure of High-Strength Steel Controlled by Hot Stamping Process
NASA Astrophysics Data System (ADS)
Ou, Hang; Zhang, Xu; Xu, Junrui; Li, Guangyao; Cui, Junjia
2018-03-01
A novel design and manufacturing method, dubbed "precast," of the cooling system and tools for a hot forming process was proposed in this paper. The integrated structures of the punch and blank holder were determined by analyzing the bending and reverse-bending deformation of the forming parts. The desired crashworthiness performance of an automotive front bumper constructed with this process was obtained by a tailored phase transformation, which generated martensite-bainite in the middle and full martensite transformation in the corner areas. Varying cooling effects in the formed parts caused the highest temperature to be located in the bottom and the lowest on the end of the formed parts. Moreover, the microstructural distributions demonstrated that the bottom possessed a relatively lower content of martensite, while, conversely, the end possessed a higher content. This was precisely the most desired phase distributions for the hot formed parts. For the six-process cycle stamping, the temperatures reached a stable status after an initial rapid increase in the first three process cycles. The microstructural results verified the feasibility of the hot forming tools under multiprocess cycles.
Multi-Dimensional Calibration of Impact Dynamic Models
NASA Technical Reports Server (NTRS)
Horta, Lucas G.; Reaves, Mercedes C.; Annett, Martin S.; Jackson, Karen E.
2011-01-01
NASA Langley, under the Subsonic Rotary Wing Program, recently completed two helicopter tests in support of an in-house effort to study crashworthiness. As part of this effort, work is on-going to investigate model calibration approaches and calibration metrics for impact dynamics models. Model calibration of impact dynamics problems has traditionally assessed model adequacy by comparing time histories from analytical predictions to test at only a few critical locations. Although this approach provides for a direct measure of the model predictive capability, overall system behavior is only qualitatively assessed using full vehicle animations. In order to understand the spatial and temporal relationships of impact loads as they migrate throughout the structure, a more quantitative approach is needed. In this work impact shapes derived from simulated time history data are used to recommend sensor placement and to assess model adequacy using time based metrics and orthogonality multi-dimensional metrics. An approach for model calibration is presented that includes metric definitions, uncertainty bounds, parameter sensitivity, and numerical optimization to estimate parameters to reconcile test with analysis. The process is illustrated using simulated experiment data.
Tang, Youming; Cao, Libo; Kan, Steven
2014-01-01
Objectives To examine the damage location distribution of five main body region injuries of maximum abbreviated injury score (MAIS) 3–6 injured occupants for nearside struck vehicle in front-to-side impact crashes. Design and setting MAIS 3–6 injured occupants information was extracted from the US-National Automotive Sampling System/Crashworthiness Data System in the year 2007; it included the head/face/neck, chest, pelvis, upper extremity and lower extremity. Struck vehicle collision damage was classified in a three-dimensional system according to the J224 Collision Deformation Classification of SAE Surface Vehicle Standard. Participants Nearside occupants seated directly adjacent to the struck side of the vehicle with MAIS 3–6 injured, in light truck vehicles–passenger cars (LTV–PC) side impact crashes. Outcome measures Distribution of MAIS 3–6 injured occupants by body regions and specific location of damage (lateral direction, horizontal direction and vertical direction) were examined. Injury risk ratio was also assessed. Results The lateral crush zone contributed to MAIS 3–6 injured occupants (n=705) and 50th centile injury risks when extended into zone 3. When the crush extended to zone 4, the injury risk ratio of MAIS 3–6 injured occupants approached 81%. The horizontal crush zones contributing to the highest injury risk ratio of MAIS 3–6 occupants were zones ‘D’ and ‘Y’, and the injury risk ratios were 25.4% and 36.9%, respectively. In contrast, the lowest injury risk ratio was 5.67% caused by zone ‘B’. The vertical crush zone which contributed to the highest injury risk ratio of MAIS 3–6 occupants was zone ‘E’, whose injury risk ratio was 58%. In contrast, the lowest injury risk ratio was 0.14% caused by zone ‘G+M’. Conclusions The highest injury risk ratio of MAIS 3–6 injured occupants caused by crush intrusion between 40 and 60 cm in LTV–PC nearside impact collisions and the damage region of the struck vehicle was in the zones ‘E’ and ‘Y’. PMID:24812190
Evaluating the Potential Benefits of Advanced Automatic Crash Notification.
Plevin, Rebecca E; Kaufman, Robert; Fraade-Blanar, Laura; Bulger, Eileen M
2017-04-01
Advanced Automatic Collision Notification (AACN) services in passenger vehicles capture crash data during collisions that could be transferred to Emergency Medical Services (EMS) providers. This study explored how EMS response times and other crash factors impacted the odds of fatality. The goal was to determine if information transmitted by AACN could help decrease mortality by allowing EMS providers to be better prepared upon arrival at the scene of a collision. The Crash Injury Research and Engineering Network (CIREN) database of the US Department of Transportation/National Highway Traffic Safety Administration (USDOT/NHTSA; Washington DC, USA) was searched for all fatal crashes between 1996 and 2012. The CIREN database also was searched for illustrative cases. The NHTSA's Fatal Analysis Reporting System (FARS) and National Automotive Sampling System Crashworthiness Data System (NASS CDS) databases were queried for all fatal crashes between 2000 and 2011 that involved a passenger vehicle. Detailed EMS time data were divided into prehospital time segments and analyzed descriptively as well as via multiple logistic regression models. The CIREN data showed that longer times from the collision to notification of EMS providers were associated with more frequent invasive interventions within the first three hours of hospital admission and more transfers from a regional hospital to a trauma center. The NASS CDS and FARS data showed that rural collisions with crash-notification times >30 minutes were more likely to be fatal than collisions with similar crash-notification times occurring in urban environments. The majority of a patient's prehospital time occurred between the arrival of EMS providers on-scene and arrival at a hospital. The need for extrication increased the on-scene time segment as well as total prehospital time. An AACN may help decrease mortality following a motor vehicle collision (MVC) by alerting EMS providers earlier and helping them discern when specialized equipment will be necessary in order to quickly extricate patients from the collision site and facilitate expeditious transfer to an appropriate hospital or trauma center. Plevin RE , Kaufman R , Fraade-Blanar L , Bulger EM . Evaluating the potential benefits of advanced automatic crash notification. Prehosp Disaster Med. 2017;32(2):156-164.
Designing for aircraft structural crashworthiness
NASA Technical Reports Server (NTRS)
Thomson, R. G.; Caiafa, C.
1981-01-01
This report describes structural aviation crash dynamics research activities being conducted on general aviation aircraft and transport aircraft. The report includes experimental and analytical correlations of load-limiting subfloor and seat configurations tested dynamically in vertical drop tests and in a horizontal sled deceleration facility. Computer predictions using a finite-element nonlinear computer program, DYCAST, of the acceleration time-histories of these innovative seat and subfloor structures are presented. Proposed application of these computer techniques, and the nonlinear lumped mass computer program KRASH, to transport aircraft crash dynamics is discussed. A proposed FAA full-scale crash test of a fully instrumented radio controlled transport airplane is also described.
Resistance Element Welding of Magnesium Alloy/austenitic Stainless Steel
NASA Astrophysics Data System (ADS)
Manladan, S. M.; Yusof, F.; Ramesh, S.; Zhang, Y.; Luo, Z.; Ling, Z.
2017-09-01
Multi-material design is increasingly applied in the automotive and aerospace industries to reduce weight, improve crash-worthiness, and reduce environmental pollution. In the present study, a novel variant of resistance spot welding technique, known as resistance element welding was used to join AZ31 Mg alloy to 316 L austenitic stainless steel. The microstructure and mechanical properties of the joints were evaluated. It was found that the nugget consisted of two zones, including a peripheral fusion zone on the stainless steel side and the main fusion zone. The tensile shear properties of the joints are superior to those obtained by traditional resistance spot welding.
Crush analysis of the foam-filled bitubal circular tube under oblique impact
NASA Astrophysics Data System (ADS)
Djamaluddin, F.; Abdullah, S.; Arrifin, A. K.; Nopiah, Z. M.
2018-02-01
This paper presents crashworthiness analysis of bitubal cylindrical tubes under different impact angular. The numerical solution of double cylindrical tubes are determined by finite element analysis (FEA). Moreover, the structure was impacted by mass block as impactor respect to longitudinal direction of the tubes. The model of structure was developed by non-linear ABAQUS sofware with variations of load angle and dimensions of tube. The outcome of this study is the respons parameters such as the peak crusing force (PCF), energy absorption (EA) and specific energy absorption (SEA), thus it can be expected this tube as the great energy absorber.
Newgard, Craig D; McConnell, K John
2008-10-01
There is concern that small stature occupants (particularly women) involved in motor vehicle crashes (MVCs) may be at risk of injury or death from frontal air bags, though evidence to substantiate this concern is lacking. We sought to assess how occupant body size (measured through height and weight) affects air bag effectiveness in mitigating the risk of serious injury, after adjusting for important crash factors. This was a retrospective cohort study using a national population-based cohort of adult front-seat occupants involved in MVCs as included in the National Automotive Sampling System Crashworthiness Data System database (NASS CDS) from 1995 to 2006. Drivers and front-seat passengers 15 years and older involved in MVCs involving passenger vehicles and light trucks were included in the analysis. The primary outcome was serious injury, defined as an Abbreviated Injury Scale (AIS) score >or=3 in any body region. Multivariable logistic regression models were used to test interaction terms (effect modification) between air bags, body size, and injury. The predicted probability of injury across body sizes was plotted to further illustrate potential differences. Sixty-nine thousand three hundred eighty-seven adult front-seat occupants during the 12-year period were included in the analysis, of which 9333 (2.3%) were seriously injured. There was no evidence that height or weight modified air bag effectiveness among all crashes (p > .40). In primary frontal collisions, there was some evidence for effect modification by weight (p = .04) but not by height (p = .59). When assessed using air bag deployment, height was a strong effect modifier (p = .0078), but not weight (p = .43). Predicted probability figures confirmed that occupant height modifies the effect of air bag deployment, but there was no similar visual evidence for body weight. In this sample, we found no consistent evidence that body size modifies the overall effectiveness of frontal air bags. However, among crashes involving air bag deployment, the effect of deployment on injury differs by occupant height, with a relative increase in the odds of serious injury among smaller occupants. In such crashes, the probability of injury with (versus without) deployment began to increase with occupant heights less than 155 cm (5'), reaching a level of statistical difference below 138 cm (4' 6'').
Fitzharris, Michael; Franklyn, Melanie; Frampton, Richard; Yang, King; Morris, Andrew; Fildes, Brian
2004-09-01
Using in-depth, real-world motor vehicle crash data from the United States and the United Kingdom, we aimed to assess the incidence and risk factors associated with thoracic aorta injuries. De-identified National Automotive Sampling System Crashworthiness Data System (U.S.) and Co-operative Crash Injury Study (U.K.) data formed the basis of this retrospective analysis. Logistic regression was used to assess the level of risk of thoracic aorta injury associated with impact direction, seat belt use and, given the asymmetry of the thoracic cavity, whether being struck toward the left side of the body was associated with increased risk in side-impact crashes. A total of 13,436 U.S. and 3,756 U.K. drivers and front seat passengers were analyzed. The incidence of thoracic aorta injury in the U.S. and U.K. samples was 1.5% (n = 197) and 1.9% (n = 70), respectively. The risk was higher for occupants seated on the side closest to the impact than for occupants involved in frontal impact crashes. This was the case irrespective of whether the force was applied toward the left (belted: relative risk [RR], 4.6; 95% confidence interval [CI], 2.9-7.1; p < 0.001) or the right side (belted: RR, 2.6; 95% CI, 1.4-5.1; p < 0.004) of the occupant's body. For occupants involved in side-impact crashes, there was no difference in the risk of thoracic aorta injury whether the impacting force was applied toward the left or toward the right side of the occupant's body. Seat belt use provided a protective benefit such that the risk of thoracic aorta injury among unbelted occupants was three times higher than among belted occupants (RR, 3.0; 95% CI, 2.2-4.3; p < 0.001); however, the benefit varied across impact direction. Thoracic aorta injuries were found to be associated with high impact severity, and being struck by a sports utility vehicle relative to a passenger vehicle (RR, 1.7; 95% CI, 1.2-2.3; p = 0.001). Aortic injuries have been conventionally associated with frontal impacts. However, emergency clinicians should be aware that occupants of side-impact crashes are at greater risk, particularly if the occupant was unbelted and involved in a crash of high impact severity.
Analysis of crash parameters and driver characteristics associated with lower limb injury.
Ye, Xin; Poplin, Gerald; Bose, Dipan; Forbes, Aaron; Hurwitz, Shepard; Shaw, Greg; Crandall, Jeff
2015-10-01
This study aims to investigate changes in frequency, risk, and patterns of lower limb injuries due to vehicle and occupant parameters as a function of vehicle model year. From the National Automotive Sampling System-Crashworthiness Data System, 10,988 observations were sampled and analyzed, representing 4.7 million belted drivers involved in frontal crashes for the years 1998-2010. A logistic regression model was developed to understand the association of sustaining knee and below knee lower limb injuries of moderate or greater severity with motor vehicle crash characteristics such as vehicle type and model years, toepan and instrument panel intrusions in addition to the occupant's age, gender, height and weight. Toepan intrusion greater than 2cm was significantly associated with an increased likelihood of injury (odds ratio: 9.10, 95% confidence interval 1.82-45.42). Females sustained a higher likelihood of distal lower limb injuries (OR: 6.83, 1.56-29.93) as compared to males. Increased mass of the driver was also found to have a positive association with injury (OR: 1.04, 1.02-1.06), while age and height were not associated with injury likelihood. Relative to passenger cars, vans exhibited a protective effect against sustaining lower limb injury (OR: 0.24, 0.07-0.78), whereas no association was shown for light trucks (OR: 1.31, 0.69-2.49) or SUVs (OR: 0.76, 0.28-2.02). To examine whether current crash testing results are representative of real-world NASS-CDS findings, data from frontal offset crash tests performed by the Insurance Institute for Highway Safety (IIHS) were examined. IIHS data indicated a decreasing trend in vehicle foot well and toepan intrusion, foot accelerations, tibia axial forces and tibia index in relation to increasing vehicle model year between the year 1995 and 2013. Over 90% of vehicles received the highest IIHS rating, with steady improvement from the upper and lower tibia index, tibia axial force and the resultant foot acceleration considering both left and right extremities. Passenger cars received the highest rating followed by SUVs and light trucks, while vans attained the lowest rating. These results demonstrate that while there has been steady improvement in vehicle crash test performance, below-knee lower extremity injuries remain the most common AIS 2+ injury in real-world frontal crashes. Copyright © 2015 Elsevier Ltd. All rights reserved.
Legislative advocacy is key to addressing teen driving deaths
Gillan, J S
2006-01-01
The increased crash risk of young, novice drivers, especially in their teenage years, has been a growing concern at both the state and federal levels. Teenage drivers are involved in fatal crashes at more than double the rate of the rest of the population per 100 000 licensed drivers. The best way of stemming these losses is to enact laws adopting graduated licensure systems that restrict young, novice drivers to conditions that reduce crash risk exposure when they first operate motor vehicles and to educate the public on the need for this legislation. Legislated teenage driving restrictions involve night‐time vehicle driving restrictions, prohibitions on other teenage passengers, and the required presence of supervising adults. These restrictions are relaxed as teenage drivers successfully progress through initial and intermediate stages of graduated licensure before being granted unrestricted driver licenses. Unfortunately, many states have incomplete graduated licensing systems that need further legislative action to raise them to the desirable three‐stage system that has been shown repeatedly to produce the greatest safety benefits. These state efforts should be buttressed by federal legislation that has proved to be crucial in allied driver behavioral concerns. Because reducing crash risk involves other strategies, stringent enforcement of primary seat belt laws as well as improved motor vehicle crash avoidance capabilities and crashworthiness must accompany efforts to reduce young driver crash risk. PMID:16788112
AACE: an innovative partnership to enhance aircraft safety
NASA Astrophysics Data System (ADS)
Shurtleff, William W.
1999-01-01
The Federal Aviation Administration established the Airworthiness Assurance Center of Excellence (AACE) in September 1997, through a cooperative agreement grant with Iowa State University (ISU) and The Ohio State University (OSU). A technical support contract with the Center is now in place as well. Initially the Center has five areas of concentration supporting advances in airworthiness assurance. These are 1. Maintenance, inspection, and repair, 2. Propulsion and fuel systems safety, 3. Crashworthiness, 4. Advanced materials, and 5. Landing gear systems performance and safety. AACE has nine core members who provide guidance to the Program Management Office at ISU/OSU through a Board of Directors. The core members are: Arizona State University, Iowa State University, Northwestern University, The Ohio State University, University of Dayton, University of Maryland, University of California - Los Angeles, Wichita State University, and Sandia National Laboratories. The organization also includes numerous academic affiliates, industry partners, government laboratories and other organizations. The Center now has over thirty technical projects supporting technical advances in airworthiness assurance. All these projects have industry guidance and support. This paper discusses the current technical program of the center and the highlights of the five-year plan for technical work. Also included is a description of the factors that make the Center an innovative partnership to promote aircraft safety.
Supercomputers for engineering analysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Goudreau, G.L.; Benson, D.J.; Hallquist, J.O.
1986-07-01
The Cray-1 and Cray X-MP/48 experience in engineering computations at the Lawrence Livermore National Laboratory is surveyed. The fully vectorized explicit DYNA and implicit NIKE finite element codes are discussed with respect to solid and structural mechanics. The main efficiencies for production analyses are currently obtained by simple CFT compiler exploitation of pipeline architecture for inner do-loop optimization. Current developmet of outer-loop multitasking is also discussed. Applications emphasis will be on 3D examples spanning earth penetrator loads analysis, target lethality assessment, and crashworthiness. The use of a vectorized large deformation shell element in both DYNA and NIKE has substantially expandedmore » 3D nonlinear capability. 25 refs., 7 figs.« less
NASA Astrophysics Data System (ADS)
Espinosa, Christine; Lachaud, Frédéric; Limido, Jérome; Lacome, Jean-Luc; Bisson, Antoine; Charlotte, Miguel
2015-05-01
Energy absorption during crushing is evaluated using a thermodynamic based continuum damage model inspired from the Matzenmiller-Lubliner-Taylors model. It was found that for crash-worthiness applications, it is necessary to couple the progressive ruin of the material to a representation of the matter openings and debris generation. Element kill technique (erosion) and/or cohesive elements are efficient but not predictive. A technique switching finite elements into discrete particles at rupture is used to create debris and accumulated mater during the crushing of the structure. Switching criteria are evaluated using the contribution of the different ruin modes in the damage evolution, energy absorption, and reaction force generation.
Driver Mortality in Paired Side Impact Collisions Due to Incompatible Vehicle Types
Crandall, C.S.
2003-01-01
Using a matched case control design, this study measured the mortality associated with paired passenger car-sport utility vehicle side impact (‘T-bone’) collisions using FARS data. Survival versus fatal outcome within the matched crash pairs was measured with matched pair odds ratios. Conditional logistic regression adjusted for multiple effects. Overall, passenger car drivers experienced greater mortality than did SUV drivers, regardless if they were in the struck or striking vehicle (odds ratio: 10.0; 95% confidence interval: 7.9, 12.5). Differential mortality persisted after adjustment for confounders. Efforts should be sought to improve passenger car side impact crashworthiness and to reduce SUV aggressivity. PMID:12941243
Vehicle performance evaluation in side impact (MDB) using ES-II dummy
NASA Astrophysics Data System (ADS)
Ganessh, T. S.; Bansode, Praveen; Revankar, Vidyakant; Kumar, Sunil
2018-02-01
Side impact collision is one of the leading causes of death. Protection of people during lateral collision is challenging because of relatively small space available to restraint occupant compared to front. Hence, it is imperative to protect the occupants in side collision. It is a function of vehicle type and restraints for side protection. This paper focuses on evaluation of injury parameters of the ES II dummy during the lateral collision of different vehicles with different spaces, sections and materials. Thus the comparison will enable us to understand the sensitivity of space, B-pillar section and material which affects the injury parameters. This study will help automotive engineers to design side impact crashworthy vehicles.
Evaluation of the First Transport Rotorcraft Airframe Crash Testbed (TRACT 1) Full-Scale Crash Test
NASA Technical Reports Server (NTRS)
Annett, Martin S.; Littell, Justin D.; Jackson, Karen E.; Bark, Lindley W.; DeWeese, Rick L.; McEntire, B. Joseph
2014-01-01
In 2012, the NASA Rotary Wing Crashworthiness Program initiated the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program by obtaining two CH-46E helicopters from the Navy CH-46E Program Office (PMA-226) at the Navy Flight Readiness Center in Cherry Point, North Carolina. Full-scale crash tests were planned to assess dynamic responses of transport-category rotorcraft under combined horizontal and vertical impact loading. The first crash test (TRACT 1) was performed at NASA Langley Research Center's Landing and Impact Research Facility (LandIR), which enables the study of critical interactions between the airframe, seat, and occupant during a controlled crash environment. The CH-46E fuselage is categorized as a medium-lift rotorcraft with fuselage dimensions comparable to a regional jet or business jet. The first TRACT test (TRACT 1) was conducted in August 2013. The primary objectives for TRACT 1 were to: (1) assess improvements to occupant loads and displacement with the use of crashworthy features such as pre-tensioning active restraints and energy absorbing seats, (2) develop novel techniques for photogrammetric data acquisition to measure occupant and airframe kinematics, and (3) provide baseline data for future comparison with a retrofitted airframe configuration. Crash test conditions for TRACT 1 were 33-ft/s forward and 25-ft/s vertical combined velocity onto soft soil, which represent a severe, but potentially survivable impact scenario. The extraordinary value of the TRACT 1 test was reflected by the breadth of meaningful experiments. A total of 8 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and photogrammetric techniques. A combination of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. Loads from ATDs in energy absorbing seats and restraints were within injury limits. Severe injury was likely for ATDs in forward facing passenger seats, legacy troop bench seats, and a three-tiered patient litter. In addition, two standing ATDs were used to evaluate the benefit of Mobile Aircrew Restraint Systems (MARS) versus a standard gunner's belt. The ATD with the MARS survived the impact, while fatal head blunt trauma occurred for the standing ATD held by the legacy gunner's belt. In addition to occupant loading, the structural response of the airframe was assessed based on accelerometers located throughout the airframe and using three-dimensional photogrammetric techniques. Analysis of the photogrammetric data indicated regions of maximum deflection and permanent deformation.
Impact and Crashworthiness Characteristics of Venera Type Landers for Future Venus Missions
NASA Technical Reports Server (NTRS)
Schroeder, Kevin; Bayandor, Javid; Samareh, Jamshid
2016-01-01
In this paper an in-depth investigation of the structural design of the Venera 9-14 landers is explored. A complete reverse engineering of the Venera lander was required. The lander was broken down into its fundamental components and analyzed. This provided in-sights into the hidden features of the design. A trade study was performed to find the sensitivity of the lander's overall mass to the variation of several key parameters. For the lander's legs, the location, length, configuration, and number are all parameterized. The size of the impact ring, the radius of the drag plate, and other design features are also parameterized, and all of these features were correlated to the change of mass of the lander. A multi-fidelity design tool used for further investigation of the parameterized lander was developed. As a design was passed down from one level to the next, the fidelity, complexity, accuracy, and run time of the model increased. The low-fidelity model was a highly nonlinear analytical model developed to rapidly predict the mass of each design. The medium and high fidelity models utilized an explicit finite element framework to investigate the performance of various landers upon impact with the surface under a range of landing conditions. This methodology allowed for a large variety of designs to be investigated by the analytical model, which identified designs with the optimum structural mass to payload ratio. As promising designs emerged, investigations in the following higher fidelity models were focused on establishing their reliability and crashworthiness. The developed design tool efficiently modelled and tested the best concepts for any scenario based on critical Venusian mission requirements and constraints. Through this program, the strengths and weaknesses inherent in the Venera-Type landers were thoroughly investigated. Key features identified for the design of robust landers will be used as foundations for the development of the next generation of landers for future exploration missions to Venus.
Materials for a new generation of vehicles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Grobstein, T.
1995-12-31
The Partnership for a New Generation of Vehicles (PNGV) is a national initiative with three goals: first, to significantly improve national competitiveness in manufacturing; second, to implement commercially viable innovations from ongoing research on conventional vehicles, and third, to develop a vehicle to achieve up to three times the fuel efficiency of today`s comparable vehicle (i.e., the 1994 Chrysler Concorde, Ford Taurus, and Chevrolet Lumina). Note this vehicle will have the equivalent customer purchase price of today`s vehicles adjusted for economics, while meeting the customers` needs for quality, performance, and utility. Eight federal agencies are currently contributing to these goals,more » as well as the three principal US automobile manufacturers, numerous automotive component suppliers, research laboratories, and universities. Materials research and development is a significant effort within PNGV. The goals in this area include development of lightweight, recyclable materials for structural applications, high strength, long-life, high temperature materials for engine components, improved materials for alternative propulsion and energy storage systems, and cost-effective process technologies and component fabrication methods. Application of advanced materials to automobiles will involve consideration of diverse factors, including weight savings, affordability, recyclability, crashworthiness, repairability, and manufacturability.« less
Experimental Photogrammetric Techniques Used on Five Full-Scale Aircraft Crash Tests
NASA Technical Reports Server (NTRS)
Littell, Justin D.
2016-01-01
Between 2013 and 2015, full-scale crash tests were conducted on five aircraft at the Landing and Impact Research Facility (LandIR) at NASA Langley Research Center (LaRC). Two tests were conducted on CH-46E airframes as part of the Transport Rotorcraft Airframe Crash Testbed (TRACT) project, and three tests were conduced on Cessna 172 aircraft as part of the Emergency Locator Transmitter Survivability and Reliability (ELTSAR) project. Each test served to evaluate a variety of crashworthy systems including: seats, occupants, restraints, composite energy absorbing structures, and Emergency Locator Transmitters. As part of each test, the aircraft were outfitted with a variety of internal and external cameras that were focused on unique aspects of the crash event. A subset of three camera was solely used in the acquisition of photogrammetric test data. Examples of this data range from simple two-dimensional marker tracking for the determination of aircraft impact conditions to entire full-scale airframe deformation to markerless tracking of Anthropomorphic Test Devices (ATDs, a.k.a. crash test dummies) during the crash event. This report describes and discusses the techniques used and implications resulting from the photogrammetric data acquired from each of the five tests.
Sunnevång, Cecilia; Sui, Bo; Lindkvist, Mats; Krafft, Maria
2015-01-01
This study aimed to investigate the crash characteristics, injury distribution, and injury mechanisms for Maximum Abbreviated Injury Score (MAIS) 2+ injured belted, near-side occupants in airbag-equipped modern vehicles. Furthermore, differences in injury distribution for senior occupants compared to non-senior occupants was investigated, as well as whether the near-side occupant injury risk to the head and thorax increases or decreases with a neighboring occupant. National Automotive Sampling System's Crashworthiness Data System (NASS-CDS) data from 2000 to 2012 were searched for all side impacts (GAD L&R, all principal direction of force) for belted occupants in modern vehicles (model year > 1999). Rollovers were excluded, and only front seat occupants over the age of 10 were included. Twelve thousand three hundred fifty-four MAIS 2+ injured occupants seated adjacent to the intruding structure (near-side) and protected by at least one deployed side airbag were studied. To evaluate the injury risk influenced by the neighboring occupant, odds ratio with an induced exposure approach was used. The most typical crash occurred either at an intersection or in a left turn where the striking vehicle impacted the target vehicle at a 60 to 70° angle, resulting in a moderate change of velocity (delta-V) and intrusion at the B-pillar. The head, thorax, and pelvis were the most frequent body regions with rib fracture the most frequent specific injury. A majority of the head injuries included brain injuries without skull fracture, and non-senior rather than senior occupants had a higher frequency of head injuries on the whole. In approximately 50% of the cases there was a neighboring occupant influencing injury outcome. Compared to non-senior occupants, the senior occupants sustained a considerably higher rate of thoracic and pelvis injuries, which should be addressed by improved thorax side airbag protection. The influence on near-side occupant injury risk by the neighboring occupant should also be further evaluated. Furthermore, side airbag performance and injury assessments in intersection crashes, especially those involving senior occupants in lower severities, should be further investigated and side impact dummy biofidelity and injury criteria must be determined for these crash scenarios.
Predicting severe injury using vehicle telemetry data.
Ayoung-Chee, Patricia; Mack, Christopher D; Kaufman, Robert; Bulger, Eileen
2013-01-01
In 2010, the National Highway Traffic Safety Administration standardized collision data collected by event data recorders, which may help determine appropriate emergency medical service (EMS) response. Previous models (e.g., General Motors ) predict severe injury (Injury Severity Score [ISS] > 15) using occupant demographics and collision data. Occupant information is not automatically available, and 12% of calls from advanced automatic collision notification providers are unanswered. To better inform EMS triage, our goal was to create a predictive model only using vehicle collision data. Using the National Automotive Sampling System Crashworthiness Data System data set, we included front-seat occupants in late-model vehicles (2000 and later) in nonrollover and rollover crashes in years 2000 to 2010. Telematic (change in velocity, direction of force, seat belt use, vehicle type and curb weight, as well as multiple impact) and nontelematic variables (maximum intrusion, narrow impact, and passenger ejection) were included. Missing data were multiply imputed. The University of Washington model was tested to predict severe injury before application of guidelines (Step 0) and for occupants who did not meet Steps 1 and 2 criteria (Step 3) of the Centers for Disease Control and Prevention Field Triage Guidelines. A probability threshold of 20% was chosen in accordance with Centers for Disease Control and Prevention recommendations. There were 28,633 crashes, involving 33,956 vehicles and 52,033 occupants, of whom 9.9% had severe injury. At Step 0, the University of Washington model sensitivity was 40.0% and positive predictive value (PPV) was 20.7%. At Step 3, the sensitivity was 32.3 % and PPV was 10.1%. Model analysis excluding nontelematic variables decreased sensitivity and PPV. The sensitivity of the re-created General Motors model was 38.5% at Step 0 and 28.1% at Step 3. We designed a model using only vehicle collision data that was predictive of severe injury at collision notification and in the field and was comparable with an existing model. These models demonstrate the potential use of advanced automatic collision notification in planning EMS response. Prognostic study, level II.
Microstructural investigations of the trimmed edge of DP980 steel sheets
NASA Astrophysics Data System (ADS)
Bhattacharya, S.; Green, D. E.; Sohmshetty, R.; Alpas, A. T.
2017-10-01
In order to reduce vehicle weight while maintaining crashworthiness, advanced high strength steels (AHSSs), such as DP980, are extensively used for manufacturing automotive body components. During trimming operations, the high tensile strength of DP980 sheets tends to cause damage of the trim edge of D2 die inserts, which result in deterioration of the edge quality. The objective of this work is to study the damage microstructures at the trimmed edge of DP980 steel sheets as a function of the number of trimming cycles. A mechanical press equipped with AISI D2 tool steel inserts was used to continuously trim 1.4 mm thick sheets of DP980 at a rate of 30 strokes/min. Cross-sectional SEM images of the trimmed edges revealed that the sheared edge quality of the DP980 sheets decreased, indicated by an increase in the burr width, with an increase in the number of trims from 40,000 to 70,000. Plastic strains were estimated using the displacements of the martensite plates within plastic flow fields of ferrite. Site-specific cross-sectional TEM samples, excised from the trimmed edge using the in-situ `lift-out' technique by focused ion-beam (FIB)-milling, revealed cracking at the ferrite/martensite interfaces after 70,000 cycles indicating an increase in the depth of deformation zone possibly due to trimming with a chipped and blunted die edge.
Delegating to the automobile: experimenting with automotive restraints in the 1970s.
Wetmore, Jameson M
2015-04-01
This article explores the attempts in the United States in the 1970s to implement a new paradigm for automobile safety-crashworthiness, the idea that automobile passengers should be protected in the event of a crash. A large number of strategies were proposed, including air bags, seatbelt modifications, mandatory belt-use laws, and ignition interlocks. Many of these did not initially come to fruition, but they did give the automobile safety community a chance to experiment with different ways of distributing responsibilities between automobile occupants, automobile manufacturers, and, to a lesser extent, government agencies. These experiments helped pave the way for the successful implementation of a number of new strategies in the 1980s, 1990s, and 2000s.
Research safety vehicle, Phase II. Volume I. Executive summary. Final report jul 75-dec 76
DOE Office of Scientific and Technical Information (OSTI.GOV)
Struble, D.
1976-12-01
Volume I summarizes the results of the Minicars Research Safety Vehicle Phase II program, as detailed in Volumes II and III. Phase I identified trends leading to the desired national social goals of the mid-1980's in vehicle crashworthiness, crash avoidance, damageability, pedestrian safety, fuel economy, emissions and cost, and characterized an RSV to satisfy them. In Phase II an RSV prototype was designed, developed and tested to demonstrate the feasibility of meeting these goals simultaneously. Although further refinement is necessary to assure operational validity, in all categories the results meet or exceed the most advanced performance specified by The Presidentialmore » Task Force on Motor Vehicle Goals beyond 1980.« less
Nonlinear static and dynamic finite element analysis of an eccentrically loaded graphite-epoxy beam
NASA Technical Reports Server (NTRS)
Fasanella, Edwin L.; Jackson, Karen E.; Jones, Lisa E.
1991-01-01
The Dynamic Crash Analysis of Structures (DYCAT) and NIKE3D nonlinear finite element codes were used to model the static and implulsive response of an eccentrically loaded graphite-epoxy beam. A 48-ply unidirectional composite beam was tested under an eccentric axial compressive load until failure. This loading configuration was chosen to highlight the capabilities of two finite element codes for modeling a highly nonlinear, large deflection structural problem which has an exact solution. These codes are currently used to perform dynamic analyses of aircraft structures under impact loads to study crashworthiness and energy absorbing capabilities. Both beam and plate element models were developed to compare with the experimental data using the DYCAST and NIKE3D codes.
Energy absorption in aluminum extrusions for a spaceframe chassis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Logan, R.W.; Perfect, S.A.; Parkinson, R.D.
1994-09-19
This work describes the design, finite-element analysis, and verifications performed by LLNL and Kaiser Aluminum for the prototype design of the CALSTART Running Chassis purpose-built electric vehicle. Component level studies, along with our previous experimental and finite-element works, provided the confidence to study the crashworthiness of a complete aluminum spaceframe. Effects of rail geometry, size, and thickness were studied in order to achieve a controlled crush of the front end structure. These included the performance of the spaceframe itself, and the additive effects of the powertrain cradle and powertrain (motor/controller in this case) as well as suspension. Various design iterationsmore » for frontal impact at moderate and high speed are explored.« less
Evaluation of Vehicle-Based Crash Severity Metrics.
Tsoi, Ada H; Gabler, Hampton C
2015-01-01
Vehicle change in velocity (delta-v) is a widely used crash severity metric used to estimate occupant injury risk. Despite its widespread use, delta-v has several limitations. Of most concern, delta-v is a vehicle-based metric which does not consider the crash pulse or the performance of occupant restraints, e.g. seatbelts and airbags. Such criticisms have prompted the search for alternative impact severity metrics based upon vehicle kinematics. The purpose of this study was to assess the ability of the occupant impact velocity (OIV), acceleration severity index (ASI), vehicle pulse index (VPI), and maximum delta-v (delta-v) to predict serious injury in real world crashes. The study was based on the analysis of event data recorders (EDRs) downloaded from the National Automotive Sampling System / Crashworthiness Data System (NASS-CDS) 2000-2013 cases. All vehicles in the sample were GM passenger cars and light trucks involved in a frontal collision. Rollover crashes were excluded. Vehicles were restricted to single-event crashes that caused an airbag deployment. All EDR data were checked for a successful, completed recording of the event and that the crash pulse was complete. The maximum abbreviated injury scale (MAIS) was used to describe occupant injury outcome. Drivers were categorized into either non-seriously injured group (MAIS2-) or seriously injured group (MAIS3+), based on the severity of any injuries to the thorax, abdomen, and spine. ASI and OIV were calculated according to the Manual for Assessing Safety Hardware. VPI was calculated according to ISO/TR 12353-3, with vehicle-specific parameters determined from U.S. New Car Assessment Program crash tests. Using binary logistic regression, the cumulative probability of injury risk was determined for each metric and assessed for statistical significance, goodness-of-fit, and prediction accuracy. The dataset included 102,744 vehicles. A Wald chi-square test showed each vehicle-based crash severity metric estimate to be a significant predictor in the model (p < 0.05). For the belted drivers, both OIV and VPI were significantly better predictors of serious injury than delta-v (p < 0.05). For the unbelted drivers, there was no statistically significant difference between delta-v, OIV, VPI, and ASI. The broad findings of this study suggest it is feasible to improve injury prediction if we consider adding restraint performance to classic measures, e.g. delta-v. Applications, such as advanced automatic crash notification, should consider the use of different metrics for belted versus unbelted occupants.
Four paradigms: traffic safety in the twentieth-century United States.
Norton, Peter
2015-04-01
Traffic safety, once neglected within the larger history of the automobile in the United States, has finally been getting the attention it always deserved. Nevertheless, historians still sometimes misappraise traffic safety in one era by the standards of another. Ahistorical assumptions have contributed to misinterpretations-for example, that Americans of the 1920s were extraordinarily tolerant of traffic casualties because they did not respond to them as more recent traffic-safety paradigms would prescribe. As a corrective, four paradigms, approximately sequential, are proposed: Safety First, Control, Crashworthiness, and Responsibility. Historians are invited to borrow, modify, or replace them, and to consider their applicability to other countries. Whether these particular paradigms survive review or not, historians who are alert to safety paradigms will produce more reliable scholarship on the history of traffic safety.
Automatic contact in DYNA3D for vehicle crashworthiness
DOE Office of Scientific and Technical Information (OSTI.GOV)
Whirley, R.G.; Engelmann, B.E.
1993-07-15
This paper presents a new formulation for the automatic definition and treatment of mechanical contact in explicit nonlinear finite element analysis. Automatic contact offers the benefits of significantly reduced model construction time and fewer opportunities for user error, but faces significant challenges in reliability and computational costs. This paper discusses in detail a new four-step automatic contact algorithm. Key aspects of the proposed method include automatic identification of adjacent and opposite surfaces in the global search phase, and the use of a smoothly varying surface normal which allows a consistent treatment of shell intersection and corner contact conditions without ad-hocmore » rules. The paper concludes with three examples which illustrate the performance of the newly proposed algorithm in the public DYNA3D code.« less
NASA Astrophysics Data System (ADS)
Wang, Wurong; Wei, Xicheng; Yang, Jun; Shi, Gang
2011-08-01
Due to its excellent strength and formability combinations, dual phase (DP) steels offer the potential to improve the vehicle crashworthiness performance without increasing car body weight and have been increasingly used into new vehicles. However, a new type of crack mode termed as shear fracture is accompanied with the application of these high strength DP steel sheets. With the cup drawing experiment to identify the limit drawing ratio (LDR) of three DP AHSS with strength level from 600 MPa to 1000 MPa, the study compared and categorized the macroscopic failure mode of these three types of materials. The metallographical observation along the direction of crack was conducted for the DP steels to discover the micro-level propagation mechanism of the fracture.