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Impact Model for Accident Reconstruction - Normal and Tangential Restitution Coefficients
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English
Abstract
A two-dimensional impact model with a capability of reverse calculation has been developed to reconstruct various types of automobile collisions. The model consists of a law of conservation of momentum and introduces a normal restitution coefficient and a tangential restitution coefficient at the impact center. Sixteen car-to-car impact tests, including side swipe type collisions, were conducted to obtain primary data for validating the model and improving its reliability in accident analysis. The relationship of the normal and tangential restitution coefficients to the collision type was obtained with a generalized impulse ratio from the analysis of test data by using the impact model.
This paper presents the formulas used in the model and demonstrates their applications to accident analysis. The following analytical formulas are introduced:
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The relationship between energy loss and delta-V.
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The relationship between restitution coefficients and energy loss.
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The relationship between equivalent friction coefficient and tangential restitution coefficient.
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Authors
Citation
Ishikawa, H., "Impact Model for Accident Reconstruction - Normal and Tangential Restitution Coefficients," SAE Technical Paper 930654, 1993, https://doi.org/10.4271/930654.Also In
References
- McHenry R. R. Development of a Computer Program to Aid the Investigation of Highway Accidents Calspan Report No. VJ-2979-V-1 December 1971 (PB 208537)
- Ishikawa H. Computer Simulation of Automobile Collision - Reconstruction of Accidents SAE Paper 851729
- Crash3 User's Guide and Technical Manual Pub. No. DOT HS 805732, NHTSA February 1981 April 1982
- Day T. D. Hargens R. L. An Overview of the EDCRASH Computes Delta-V SAE Paper 870045
- Woolley R. L. The IMPAC Computer Program for Accident Reconstruction SAE Paper 850254
- Brach R. M. An Impact Moment Coefficient for Vehicle Collision Analysis SAE Paper 770014
- Goldsmith W. Impact - The Theory and Physical Behavior of Colliding Solids London Edward Arnold 10 16 1960
- Brach R. M. Analysis of Planar Vehicle Collisions Using Equations of Impulse and Momentum Accident Analysis and Prevention 15 2 105 120 1983
- Brach R. M. Rigid Body Collisions Transactions of the ASME Journal of Applied Mechanics, 89-APM-3 1989
- Woolley R. L. Warner C. Y. Tagg M. D. Inaccuracies in the CRASH3 Program SAE Paper 850255
- Brach R. M. Brach R. M. A Review of Impact Models for Vehicle Collision SAE Paper 870048
- Ishikawa H. Introduction of a Negative Restitution Coefficient and a Rotational Restitution Coefficient for Analysis of Two-Dimensional Impact Journal of Automobile Research 12 4 130 133 April 1990
- Ishikawa H. Kinematics of Automobile Collision - A Negative Restitution Coefficient and a Rotational Restitution Coefficient for Analysis of Two-Dimensional Impact JSAE Transactions 22 4 101 106 October 1991
- Brach R. M. Restitution in Point Collisions Chapter in Computational Aspects of Impact and Penetration Kulak R. F. Schwer L. Elmepress International Lausanne Switzerland 1991