This article describes the development of a load sensing face (lsf) which detects localized facial forces in laboratory car crash conditions. piezoelectric sensors provide pressure time histories. Design properties and characteristics of the lsf are described, as wellas the sensor technique used. Sled tests with a lsf equipped dummy are presented. The purpose was to evaluate the efficiency of the method in registering facial impact magnitude and location with different restraint and seat position combinations. The lsf was also used in drop testing of steering wheels. various impact velocities and impact points as well as the repeatability were studied, as well as therepeatability of the results. The results showed that the lsf couldbe an excellent tool for establishing injury criteria. The results were sufficiently repeatable to be considered accurate. However, thedisadvantage of the method is that the force/deflection characteristics are much stiffer than those of a human face. Consequently injury risk junctions measured for humans cannot easily be transferred into pressure thresholds for the lsf.
Abstract