Structural and biomechanical crashworthiness using multi-body dynamics

Abstract Multi-body dynamics methodologies are the prime tools used for the design and analysis of structural and biomechanical systems that undergo multiple-impact conditions during relatively long simulation times and for which the large rigid body motion of the components is of major importance. A computational methodology based on the use of Cartesian coordinates is presented to represent the general multi-body system. In order to represent the contact between the system components a continuous force model is introduced in the framework of the chosen multi-body formulation. The structural crashworthiness requires that some of the system components are allowed to undergo deformations. A methodology that uses the non-linear finite element method integrated with the classical multi-body dynamics equations is proposed here. The formulations are demonstrated by an application to a complex crash scenario represented by a rollover of an all-terrain vehicle with several occupants inside. Special emphasis is put on the determination of the occupants' initial positions using video cameras and spatial position reconstruction techniques in order to allow for the study of out-of-position occupant dynamics. It is shown that the methodology proposed here allows not only for the description of the major structural deformations of the vehicle but also for the evaluation of the occupants' kinematics.