RECONSTRUCTION OF MOTOR VEHICLE ACCIDENTS: A TECHNICAL COMPENDIUM. ENERGY LOSS IN VEHICLE COLLISIONS

Reconstruction methods typically are based upon impact velocity changes computed by one of two approaches. These are damage based or crush measurement techniques and impulse and momentum equation solutions. Crush measurement techniques have an analytical foundation based to a large extent on point mass collision theory, limited primarily to collisions of vehicles with a common final velocity at the contact surface. Impulse and momentum methods can treat a full, 2-dimensional collision with arbitrary restitution and friction coefficients. As such, their analytical foundation is much broader than damage based or crush measurement methods. The energy loss relationship and the tangential correction factor form an important part of the crush measurement methods. These two relationships are derived in a more general fashion than has been available. These two approaches are compared in this paper. The comparison focuses on the ability to accurately calculate energy loss. Data from some of the RICSAC experimental collisions is analyzed using the crush measurement model and the impulse and momentum model. The latter gives consistently low estimates of energy loss with accuracies ranging from -33% to 0%. The crush measurement model gives energy loss estimates which range from -55% to 109% of the experimental values. Though the crush measurement technique accuracy depends directly upon the ability to estimate of energy loss, the method appears to be less accurate in this respect than the impulse and momentum method.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0898831229
• Corporate Authors:

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096
• Authors:
  • Brach, R M
• Publication Date: 1989

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 3-12
• Serial:
  • Publication of: ENGLISH HISTORIC TOWNS FORUM
  • Publisher: ENGLISH HISTORIC TOWNS FORUM

Subject/Index Terms

• TRT Terms: Coefficient of friction; Crash injury research; Crash tests; Crashes; Dissipation; Impact studies; Impulse tests; Momentum; Research; Testing
• Uncontrolled Terms: Model tests
• Old TRIS Terms: Impulse testing
• Subject Areas: Energy; Highways; Research; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00607266
• Record Type: Publication
• ISBN: 0-89883-122-9
• Report/Paper Numbers: PT-34
• Contract Numbers: FH-11-7526
• Files: TRIS
• Created Date: Apr 30 1991 12:00AM