A new oblique impact test for motorcycle helmets is described, simulating a fall from a motorcycle on to the road surface or the windshield of a car. An instrumented headform falls vertically to impact a horizontally moving rigid rough or deformable surface. Both the impact site on the helmet, and the vertical and horizontal velocities, can be varied, while the headform linear and rotational accelerations are measured. The rig was used to compare a new helmet design with current helmets, which are designed to pass impact tests in which the impact force is perpendicular to the helmet surface. The new design, which has a low friction layer between the shell and the liner, reduced, by up to 50%, the rotational acceleration of the head compared with conventional designs. (Author/publisher)
Abstract