Several different computer programs are used by crash investigators to estimate the severity of impact to motor vehicles involved in different types of crashes. Crash severity is most often expressed as the change in velocity, or Delta V, experienced by the case vehicle during the impact event, or by an equivalent barrier impact speed. However, the accuracy of these programs is uncertain and has been particularly questioned for some crash conditions such as offset-frontal impacts and pole impacts. Crash tests provide a unique opportunity to examine the accuracy of the different computer programs and their various program options and input parameters because the actual crash severity is measured and therefore known. In this study, residual crush measurements were taken on seven vehicles used in crash tests conducted by General Motors in GM/DOT Project B.3 "Fire Initiation and Propagation Tests.” The tests include three offset-frontal pole impacts, three offset-frontal impacts, and one offset-rear impact. These crush measurements were used as input to three different crash-reconstruction programs that are in common use today. The resulting change in velocity estimates are compared to the change in velocity measured in the crash test. Different program subroutines and options were selected, and different values and sources of input parameters were used, to determine their effects on the accuracy of the reconstruction results. (Author/publisher)
Samenvatting