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Computational Consideration of Crush Energy Estimation in Frontal Collisions with Underride and Lateral Offset
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 16, 2012 by SAE International in United States
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The use of stiffness coefficients is a well-established method for estimating the crush energy of passenger vehicles involved in frontal impact. This methodology, as well as other crush energy models, have been adapted to take into account laterally offset frontal impacts. On the other hand, methods for estimating crush energy and/or Equivalent Barrier Speed (EBS) of frontal underride collisions (vertical offset) require more development. Further, there is a need for crush energy estimation models for cases of combined lateral and vertical offset impacts as well. The objective of this research is to computationally explore the effect of lateral offset, as well as combined lateral and vertical offset on the crush energy absorption of a car in a frontal collision and the feasibility of a generalized stiffness-coefficient-based EBS approximation approach.
The finite element model of a 1990 Ford Taurus, which was improved in previously published research, was further validated against seven full-frontal crash tests. For the purpose of this work, the validation scope was limited to the relation between crush energy and residual crush. A 50% lateral offset impact into a deformable barrier was also analyzed for crush energy and was compared to the full-frontal tests. Computational simulations were conducted at speeds ranging from 20-40 mph (32-64 kph) with three impact barrier configurations: 1) Lateral offset impact into a rigid barrier with no vertical offset, 2) lateral offset impact into a rigid barrier with a 22.5″ (570 mm) vertical offset, and 3) lateral offset impact into a rigid trailer rear impact guard with a fixed 22.5″ (570 mm) vertical offset. The rigid rear impact guard geometry was incorporated into this work as a first approximation toward understanding crush energy in trailer rear underride collisions including lateral offset. The degree of lateral offset was varied from 0 (100% frontal engagement) to 80% (20% frontal engagement).
The simulation results were used to establish a relationship between the vehicle crush measurement and the crush energy. It was observed that for up to 70% lateral offset (30% engagement) and a 20-40-mph range of impact speeds, the relationship between crush profile area and the square root of crush energy remains mostly unchanged. For each impact configuration, an error analysis was conducted to establish a range of confidence for the observed invariance of the relationship between crush area and square root of crush energy. It was determined that the invariance holds true within a 10% estimation error in EBS for the range of speeds and lateral/vertical offset covered by this paper.
CitationCummins, C. and Tavakoli, M., "Computational Consideration of Crush Energy Estimation in Frontal Collisions with Underride and Lateral Offset," SAE Technical Paper 2012-01-0595, 2012, https://doi.org/10.4271/2012-01-0595.
- Campbell, K. “Energy Basis for Collision Severity,” SAE Technical Paper 740565 1974 10.4271/740565
- Woolley, R. “Non-Linear Damage Analysis in Accident Reconstruction,” SAE Technical Paper 2001-01-0504 2001 10.4271/2001-01-0504
- Fonda, A. “Principles of Crush Energy Determination,” SAE Technical Paper 1999-01-0106 1999 10.4271/1999-01-0106
- Fonda, A. “Crush Energy Formulations and Single-Event Reconstruction,” SAE Technical Paper 900099 1990 10.4271/900099
- Prasad, A. “CRASH3 Damage Algorithm Reformulation for Front and Rear Collisions,” SAE Technical Paper 900098 1990 10.4271/900098
- Strother, C. Woolley, R. James, M. “A Comparison Between NHTSA Crash Test Data and CRASH3 Frontal Stiffness Coefficients,” SAE Technical Paper 900101 1990 10.4271/900101
- Varat, M. Husher, S. Kerkhoff, J. “An Analysis of Trends of Vehicle Frontal Impact Stiffness,” SAE Technical Paper 940914 1994 10.4271/940914
- Varat, M. Husher, S. “Vehicle Crash Severity Assessment in Lateral Pole Impacts,” SAE Technical Paper 1999-01-0100 1999 10.4271/1999-01-0100
- Welsh, K. Struble, D. “Crush Energy and Structural Characterization,” SAE Technical Paper 1999-01-0099 1999 10.4271/1999-01-0099
- Woolley, R. Asay, A. Jewkes, D. Monson, C. “Crash Testing with a Massive Moving Barrier as an Accident Reconstruction Tool,” SAE Technical Paper 2000-01-0604 2000 10.4271/2000-01-0604
- Kerkhoff, J. Husher, S. Varat, M. Busenga, A. et al. “An Investigation into Vehicle Frontal Impact Stiffness, BEV and Repeated Testing for Reconstruction,” SAE Technical Paper 930899 1993 10.4271/930899
- Nystrom, G. Kost, G. Werner, S. “Stiffness Parameters for Vehicle Collision Analysis,” SAE Technical Paper 910119 1991 10.4271/910119
- Strother, C. Woolley, R. James, M. Warner, C. “Crush Energy in Accident Reconstruction,” SAE Technical Paper 860371 1986 10.4271/860371
- Marine, M. Wirth, J. Peters, B. Thomas, T. “Override/Underride Crush Energy: Results from Vertically Offset Barrier Impacts,” SAE Technical Paper 2005-01-1202 2005 10.4271/2005-01-1202
- Validation of a Finite Element Model of a Passenger Vehicle, Extension of the Model to Simulate Underride Collisions, and Establishment of a Physical Model Relating Underride Crush Energy to Residual Crush. Valliappan, P. Kettering University Masters Thesis 2005
- Tavakoli, M. Valliappan, P. Pranesh, A. Savage, C. “Estimation of Frontal Crush Stiffness Coefficients for Car-to-Heavy Truck Underride Collisions,” SAE Technical Paper 2007-01-0731 2007 10.4271/2007-01-0731
- Tavakoli, M. George, V. “Characteristics of Trailer Rear Impact Guard - Interdependence of Guard Strength, Energy Absorption, Occupant Acceleration Forces and Passenger Compartment Intrusion,” SAE Technical Paper 2008-01-0155 2008 10.4271/2008-01-0155
- 30 MPH Frontal Barrier Impact of a 1993 Ford Taurus 4-Door Sedan. Travale, D. Levan, W. DOT-Research and Special Programs Administration, DTRS-57-90-C-00104 Aug 1993
- New Car Assessment Program (NCAP), Frontal Barrier Impact Test of a 1993 Ford Taurus 4-Door Sedan. Markusic, C. DOT-National Highway Traffic safety Administration, DTNH22-90-D-22121 Apr 1993
- Final Report of FMVSS Nos. 208, 212, 219 (partial), and 301 Compliance Testing of a 1993 Ford, Taurus 4-Door Sedan. Markusic, C. DOT-National Highway Traffic Safety Administration, DTNH22-90-C-21003 Nov 1992
- New Car Assessment Program (NCAP) Frontal Barrier Impact Test of a 1990 Ford Taurus 4-Door Sedan. Kilgallon, M. Levan, W. DOT-National Highway Traffic Safety Administration, DTNH22-87-D-02012 Jan 1990
- 35 mph Frontal Barrier Impact of a 1993 Ford Taurus 4-Door Sedan. Travale, D. Levan, W. DOT-National Highway Traffic Safety Administration, DTRS-57-90-00104 Aug 1993
- Final Report of FMVSS Nos. 208, 212, 219 (partial) and 301 Compliance Testing of a 1990 Ford Taurus L 4-Door Sedan. Paolini, V. Travale, D. Levan, W. DOT-National Highway Traffic Safety Administration, DTNH22-88-C-01038 Jan 1990
- NHTSA New Car Assessment Program (NCAP) Frontal Barrier Impact Test of a 1991 Ford Taurus 4-Door Station Wagon. Paolini, V. Kilgallon, M. Levan, W. DOT-National Highway Traffic Safety Administration, DTNH22-90-D-02121 Apr 1991
- 64.7 kph Frontal 50% Overlapped Impact of a 1994 Ford Taurus into an EEVC Deformable Barrier. Evans, R. Travale, D. DOT-Research and Special Programs Administration, DTRS-57-90-C-00104 Sept 1994
- Final Report of a 1990 Ford Taurus into Heavy Truck Rigid Rear Underride Guard in Support of CRASH3 Damage Algorithm Reformation. National Highway Traffic Safety Administration, DOT HS 808 231 June 1993
- Development of a Passenger Vehicle Finite Element Model. National Highway Traffic Safety Administration, DOT HS 808 145 Nov. 1993
- Development and Validation of an NCAP Simulation using LS-DYNA3D. Marzougui, D. Kan, C. Bedewi, N. Fourth International LSDYNA3D Conference Cray Research 319 332 September 1996