Head protection with cyclist helmet in impact against vehicle A-pillar

ABSTRACTIn vehicle–cyclist collisions, the head of cyclists impacts frequently against the windshield and the A-pillar of the vehicle. Accident analyses show that the head injury risk is high in impacts with stiff A-pillars. In this research, the head protection with cyclist helmets in impacts against the A-pillar was investigated from experiments and finite element (FE) analyses. The headform impact tests were conducted using the pedestrian headform with and without a cyclist helmet. In the A-pillar impact at 35 km/h, the HIC reduced substantially from without helmet (4815) to with helmet (3000) though it was far above the injury acceptance level (1000). The head protection by helmets in impacts against A-pillars might be limited because of high impact velocities of the head and A-pillar stiffness. The FE simulations of the headform impacts indicated that the helmet liner deformed locally and bottomed-out in the A-pillar impacts, whereas the A-pillar deformation was small. In the FE analysis of a human h...