Development of energy absorbing devices using a kinetostatic multibody dynamics methodology

Abstract

Abstract A kinetostatic approach based on flexible multibody dynamics for crashworthiness and structural impact of vehicles is presented here. The equations of motion for a partially flexible body composed of a rigid part and a flexible part are derived accounting for the inertial coupling between each component's gross motion and its elastodynamics. For components having a mass for the flexible part much smaller than the mass of their rigid part the inertial coupling can be neglected. Under these assumptions the flexible part of the body behaves as a massless structure attached to the rigid body and it can be analysed as a separate non-linear structure. The deformations of this flexible part are added to the motion of the rigid part to obtain the complete motion of the flexible body. This computer-based procedure is a kinetostatic method for the analysis of flexible multibody systems subjected to non-linear deformations and impact conditions which is applied to the study of low speed impact of vehicles. The proposed methodology is applied to the study of a new design for energy absorbing devices. Several simulations of the vehicle impact against a rigid wall with different incoming speeds and impact angles are performed and the behaviour of the vehicle occupant during the impact is analysed.