Friction effects in pedestrian headform impacts with engine hoods

In the pedestrian headform impact test mandated by the European pedestrian safety requirements, the contact friction between the headform and the engine hood affects the headform kinematics and head injury criterion (HIC) to some extent. This study shows that the friction effect is more significant with child headform impact than with adult headform impact and the relative angle between the headform impact direction and the hood surface greatly affects the headform impact sensitivity to the friction coefficient. The sensitivity of the headform kinematics to the friction coefficient is also analyzed. The results show that accurate friction coefficients are needed to improve predictions of pedestrian headform impacts with hoods.