A MULTIBODY FINITE ELEMENT ANALYSIS APPROACH FOR MODELING OF CRASH DYNAMIC-RESPONSES/

Computer models of the human body are robust tools for gaining insight into the gross motion of ground vehicle or aircraft occupants and eva luating the loads and deformations of their critical parts. The knowle dge of occupant responses will help in the determination of the type a nd probable causes of injuries that may be sustained during a crash. A n important aspect in crash analysis is how the large motion of the re latively rigid segments of an occupant, such as the limbs, and the sma ll deformations of flexible segments, such as the spine column, are in terrelated. To this end a general methodology for kineto-static analys is of multibody systems with flexible structures undergoing large moti on and structural deformations is developed Rigid multibody dynamics i s used to predict the gross motions and displacements at the boundarie s between the relatively bulky (rigid) bodies and relatively flexible ones. A mired boundary-condition finite-element analysis is formulated and solved at every numerical integration rime to determine the corre sponding reaction forces and moments at the boundaries and also the st ructural deformations. Based on this methodology, a multibody model of the occupant with a nonlinear finite element model of the lumbar spin e is developed for a Hybrid Il anthropomorphic crash test dummy. The a nalytical results obtained are compared with the experimental results from the impact sled tests. Comparison of the results has shown better correlation between the analyses and the experiments compared with ea rlier studies.