A Multibody/Finite Element Analysis Approach for Modeling of Crash Dynamic Responses

Abstract

Abstract Computer models of the human body are robust tools for gaining insight into the gross motion of ground vehicle or aircraft occupants and evaluating the loads and deformations of their critical parts. The knowledge of occupant responses will help in the determination of the type and probable causes of injuries that may be sustained during a crash. One important aspect in crash analysis is how the large motion of the relatively rigid segments of an occupant, such as the limbs, and the small deformations of flexible segments, such as the spine column, are inter-related. To this end, a general methodology for kineto-static analysis of multibody systems with flexible structures undergoing large motion and complicated structural deformations is developed. Rigid multibody dynamics is used to predict the gross motions and displacements at the boundaries. Finite element analysis is then performed to determine the corresponding loads and deformations of the entire structure. Based on this methodology, a multibody model of the occupant with a finite element model of the lumbar spine is developed for a Hybrid II (Part 572) anthropomorphic test dummy. The analytical results obtained from the code are correlated with the experimental results from the impact sled tests. Comparison of the results has shown much closer match between the analyses and the experiments.