Lower Extremity Finite Element Model for Occupant Crash Studies

In collaboration with the National Highway Traffic Safety Administration, LLNL has completed a lower extremity model (LEM) designed to allow the study of occupant injuries to the major bones and ligamentous soft tissues as a result of vehicle collisions. This specific focus results from the fact that seat belts and air bags have not been able to reduce injuries to the lower extremities. The model is based on anatomically correct digitized bone surfaces and the major ligaments, tendons and muscles have been included. We have investigated bone and soft tissue injury mechanisms in vehicle crash studies using non-linear large deformation finite element codes. As an approximation of a crash event, we have simulated occupant deceleration and loading that occurs in a sled test environment. Computed loads in the model compare favorably with those obtained from the experimental crash simulation. The model is designed to be integrated into existing vehicle crash models.