Search Results

The speed change, Delta V, and the PDOF, principal direction of force, on a vehicle in an accident can be taken together to form a useful measure of accident severity. Many studies have correlated the combined effect of these with the statistical probability of an injury of a certain type and severity according to the AIS (abbreviated injury scale). The usefulness of this concept is enhanced by considering the effective Delta V and PDOF at occupant locations in a vehicle by taking into account the effect of the vehicle rotation. The method of calculating the Delta V at the occupant location is presented in this paper.

Tread belt separation and detachment is a common failure mode of radial tires. The accident reconstructionist is frequently asked to evaluate the effect of tread belt separation and detachment relative to the occurrence of an accident. Publications have previously been directed toward defining the effects of rapid tire deflation on vehicle drag and handling. However, little has been written about the singular effect of the loss of the tire tread belt relative to vehicle handling. The loss of a tread belt from a tire may be followed by rapid deflation. The combined separation and detachment event may have similar effects on vehicle handling as a rapid deflation event. To evaluate the effect of the loss of a tread belt without tire deflation, the authors tested tires prepared so that the tread belts could be intentionally separated while driving at speeds between 50 and 75 miles per hour.