Motorcycle helmet load spreading performance for impacts into rigid and deformable objects.

There is accident evidence that when a helmetted motorcyclist impacts a deformable steel panel on a car, there may not be any measureable crushing of the polystyrene foam helmet liner. This is especially the case if the helmet shell material is fibreglass, and if there is double curvature of the helmet shell at the impact site. To investigate this, laboratory impact tests were made in which the headform accelerations, the pressure distributions on both sides of the helmet liner, and th strain distribution in the crushed foam were measured.