Finite Element Modeling of Gross Motion of Human Cadavers in Side Impact

Seventeen Heidelberg type cadaveric side impact sled tests, two sled-to-sled tests, and forty-four pendulum tests have been conducted at Wayne State University, to determine human responses and tolerances in lateral collisions. This paper describes the development of a simplified finite element model of a human occupant in a side impact configuration to simulate those cadaveric experiments. The twelve ribs were modeled by shell elements. The visceral contents were modeled as an elastic solid accompanied by an array of discrete dampers. Bone condition factors were obtained after autopsy to provide material properties for the model. The major parameters used for comparison are contact forces at the level of shoulder, thorax, abdomen and pelvis, lateral accelerations of ribs 4 and 8 and of T12, thoracic compression and injury functions V*C, TTI and ASA. A total of four runs to simulate Heidelberg type sled tests, eight runs to simulate pendulum tests and two runs to simulate sled-to-sled tests were performed. Chest band data from the latest sled-to-sled tests were compared with the calculated deformable chest contours. It is found that there is a fair agreement between model results and experimental data. The model can be used to estimate the current chest injury parameters of an elderly occupant involved in a side impact. However, an accurate anatomical representation of the head, neck, shoulder and pelvis was not attempted, and the calculated stresses and strains have not been compared with human data.