Validation of restoration time for pedestrian headform impactor skin

Abstract

New technical standards for pedestrian head and leg protection in which the headform and legform impact test is conducted against vehicle bonnet and bumper were introduced in Japan as of April 2013. In the headform impact test, an impactor simulating the pedestrian head is used. To simulate the impact response when the human head is dropped, the headform impactor is fitted with a synthetic resin skin made of polyvinyl chloride. Since the skin is non-metallic, it may become deformed and affect the injury reference value in the case where consecutive tests are conducted. It is considered that the skin is restored after a certain period of time after collision. However, up until the present, the exact time required for the restoration had been unclear. Currently, headform impact tests against vehicle bonnet are conducted at a 2-h interval without any scientific background. Therefore, the purpose of this study is to validate the 2-h time interval required for the skin to be restored after collision. By conducting headform impact tests against vehicle bonnet and drop certification tests regulated by the technical standard at different time intervals, we investigated the restoring time for pedestrian headform impactor skin for consecutive impacts.