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The performance of pedestrian surrogates including a mathematical model is assessed on the basis of a comparison between a sample of real accidents and the results of simulated collisions. For this purpose a representative standard test program was derived from the characteristics of real accidents. A substantial increase in average injury severity is observed in reality between impact speeds of 25 and 35 km/h. This finding is reflected in the simulated collisions insofar, as the measured or calculated loadings of the surrogate in general exceed the known tolerance limits only if the impact speed is in excess of 30 km/h. The lack of surrogate motion prior to impact is shown to cause the largest differences in comparison to real accident circumstances and their outcome. Moreover, the details of the measured accelerations during contact exhibit a large variability and their significance with regard to injury mechanisms remains to be established.

A primary cause of severe injury experienced by a pedestrian who is impacted by the front of a vehicle consists in the head impact on the hood during the loading phase of the accident. Impact speed and vehicle front geometry are the most important factors which govern the severity of this impact. The aim of the present study is to analyse the motion patterns occuring during impact, particularly those of the head, and to identify a favourable front geometry in view of a reduced injury hazard. The investigations are based on impact tests performed on a sled with a vehicle front having a variable front geometry and at different impact speeds. The surrogate was a modified 572 ATD (HUMANOID) equipped with 18 accelerometers and whose head trajectory during impact was determined by high-speed cine-photogrammetry. Moreover, mathematical simulation was applied to the problem utilizing an extended version of the CALSPAN CVS computer program.