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Sudden tire deflation, or blow-out, is sometimes cited as the cause of a crash. Safety researchers have previously attempted to study the loss of vehicle control resulting from a blow-out with some success using computer simulation. However, the simplified models used in these studies did little to expose the true transient nature of the handling problem created by a blown tire. New developments in vehicle simulation technology have made possible the detailed analysis of transient vehicle behavior during and after a blow-out. This paper presents the results of an experimental blow-out study with a comparison to computer simulations. In the experiments, a vehicle was driven under steady state conditions and a blow-out was induced at the right rear tire. Various driver steering and braking inputs were attempted, and the vehicle response was recorded. These events were then simulated using EDVSM. A comparison between experimental and simulated results is presented.

Computer models used to study crashes require information to describe the vehicles. Information such as weight, length, wheelbase, tire locations, crush stiffness, tire parameters, etc. all require a reliable source. Usually the tire parameters are difficult to obtain. Analysts will routinely use default or “typical” values. In 1999, Engineering Dynamics Corp. (EDC) attempted to address this issue, with support from many in the field of crash reconstruction, by conducting tire tests. The resulting tire test data will be used to study motor vehicle performance. The computer simulations in use today require information about tire properties or lookup tables that must be extracted from raw collected data. This paper presents a basic overview of the tire test data and a technique for extracting the required tire parameters for use in computer simulation modeling.

This paper describes how a photogrammetric analysis computer program entitled FOTOGRAM™ is used with a personal computer. The FOTOGRAM program was described in a paper entitled “Photogrammetric Analysis Using the Personal Computer” by Brelin, Cichowski, and Holcomo.(1)* The technique described herein utilizes field examples to show how skid mark data are extracted from photographs using manual as well as electronic digitization methods. The digitized photographic data are then converted with the FOTOGRAM computer program into ‘real-world’ data points that may be plotted on a collision scene schematic. Thus, the actual path of the vehicle during skidding and/or tire marking can be determined for use in reconstructing the accident.