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Effects of Mass and Stiffness Ratio Variation on Vehicle Speed Change and Closing Speed Calculations
Technical Paper
2003-01-0890
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
In accident reconstruction, parameters such as the struck vehicle change in speed and the closing speed can usually be determined by means of conservation of energy and conservation of momentum approaches. While others have considered limiting cases of the effects of mass and stiffness on vehicle speed change and closing speed calculations, the full spectrum of variations in vehicle stiffness and mass ratios have not been rigorously evaluated.
This paper presents a discussion of the effects on the calculated vehicle speed change as a function of the variation of the mass and stiffness ratios. Closed form analytical solutions and graphical representations are derived and depicted for the situations in which the ratio of the barrier impact test masses equate to that of the ratio of the vehicle masses for the reconstructed situation in question and for the scenario in which they do not. Closed form solutions are provided for global maxima and minima for the non-dimensional multiplier of the barrier equivalent velocity (BEV) and restitution term (1+e) as functions of the non-dimensional vehicle mass and stiffness ratios. A practical example is provided demonstrating the application of these principles and findings. As demonstrated in a simplified example, the analytical tools provided in this paper are useful in performing reconstructions for two vehicle collisions in which significant ranges exist in the stiffness and mass parameters for one of the vehicles secondary to incomplete identification.
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Citation
Singh, J., Welcher, J., and Perry, J., "Effects of Mass and Stiffness Ratio Variation on Vehicle Speed Change and Closing Speed Calculations," SAE Technical Paper 2003-01-0890, 2003, https://doi.org/10.4271/2003-01-0890.Also In
Accident Reconstruction from the SAE 2003 World Congress on CD-ROM
Number: SP-1773CD; Published: 2003-03-03
Number: SP-1773CD; Published: 2003-03-03
References
- Burkhard, Peter M. “ΔV, BEV and Coefficient of Restitution Relationships as Applied to the Interpretation of Vehicle Crash Test Data,” Society of Automotive Engineers SAE No. 2001-01-0499 2001
- Burkhard, Peter M. “Determination of b 1 Coefficients from Lower and Higher Speed Impacts Using Peak Force,” Society of Automotive Engineers SAE No. 2001-01-0501 2001
- Campbell, Kenneth L. “Energy as a Basis for Accident Severity - A Preliminary Study.” The University of Wisconsin Engineering - Automotive 1972
- Campbell, Kenneth L. “Energy Basis for Collision Severity,” Society of Automotive Engineers SAE No. 740565 1974
- Carpenter, Nicholas J Welcher Judson B. “Stiffness and Crush Energy Analysis for Vehicle Collision and its Relationship to Barrier Equivalent Velocity (BEV),” Society of Automotive Engineers SAE No. 2001-01-0500 2001
- Edwards, CH Penney David E Calculus and Analytic Geometry Prentice-Hall Englewood Cliffs, New Jersey 1986
- Emori, Richard I. “Analytical Approach to Automobile Collisions,” Society of Automotive Engineers SAE No. 680016 1968.
- Hight, Philip V Lent-Koop D Bruce Hight Robert A. “Barrier Equivalent Velocity, Delta-V and CRASH3 Stiffness in Automobile Collisions,” Society of Automotive Engineers SAE No. 850437 1984
- Kerkhoff, John F. Husher Stein E. Varat Michael S. Busenga Alison M. Hamilton Kevin “An Investigation into Vehicle Frontal Impact Stiffness, BEV and Repeated Testing for Reconstruction,” SAE No. 930899 1993
- “Crush Stiffness Coefficients for Vehicle Model Years 1960-1992.” Neptune Engineering 1992
- Traffic Safety Facts 2000: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System National Highway Traffic Safety Administration. National Center for Statistics and Analysis US Department of Transportation December 2001
- Varat, Michael S. “Barrier Equivalent Velocity Analysis in Accident Reconstruction,” Accident Reconstruction TOPTEC: Special Topics Society of Automotive Engineers Embassy Suites Hotel, Tempe, Arizona May 22-23 2001
- Varat, Michael S. “Crash Severity Analysis in Accident Reconstruction: The use of BEV and ΔV,” Southwestern Association of Technical Accident Investigators [SATAI] Conference SATAI Phoenix, Arizona 2001
- NADA Official Older Used Car Guide National Automotive Dealers Association (NADA) Appraisal Guides September - December 2002