A quasi-static contact model for global dynamic simulation of multibody system with contact-impact

Abstract

The global impact dynamics of multibody system is challenging due to the multi-scale characteristics of slow-changing non-contact process and fast-changing impact process. To solve the contradiction between the impact accuracy and the global simulation efficiency, a novel quasi-static contact model is proposed where the local contact domain is finely discretized and the energy loss caused by elastoplasticity is considered, and the real-time force-displacement interaction is established to execute the global integration capably. Through the experimental case of flexible pendulum impact, the proposed model is compared with measurements and existing methods, including impulse method, continuous contact force method and nonlinear finite element method. It is shown that the impulse method and continuous contact force method are both sensitive to the coefficient of restitution, yielding uncertain results. The nonlinear finite element method can accurately describe the impact process, but its calculation scale is too large to apply to the global simulation. The quasi-static model can accurately describe the response of the global process and does not rely on artificial selection of any parameters, and the calculation efficiency is greatly improved compared with the nonlinear finite element method.