Head Model for Impact

A human head model has been developed primarily for use in evaluation of impact attenuation properties of football helmets, but is also applicable in automobile impact safety tests. Using firm silicon rubber molds made from impressions of cadaver bones, a skull and mandible were each cast in one piece using a self-skinning urethane foam that hardens into cross section geometry similar to the human bone. A rubber gel material is used to simulate the brain. The skull and attached mandible are overlayed with repairable silicon rubber skin having puncture and sliding-over-bone characteristics similar to human skin. At present, the model has a rudimentary solid silicon rubber neck, through the center of which runs a flexible steel cable attached at the foramen magnum. The cable is used to attach the head to a carriage or anthropometric dummy and can be adjusted in tension to give various degrees of flexibility. Response of the head is determined by a triaxial accelerometer mounted in a cavity in the skull that is located at the head c.g. and is conveniently accessible from beneath the mandible. Static load-deflection tests and impacts have been conducted on both the model and several cadavers. Results show that the response of the model falls into the cadaver range so that injury indexes can be applied directly to the model. The model is rugged, repeatable, and practical to use in situations where either protection is worn on the head or a frangible headform is desired.