The Impact Dynamics of Flexible Multibody System by a Partition Method

摘要

A partition method for the impact dynamics of a flexible multibody system with large overall motion is proposed, based on the contact constraints.Firstly, according to the rigid-flexible coupling dynamic theory of flexible multibody systems, the flexible multibody system’s rigid-flexible coupling dynamic equations without impact are established.Secondly, the system’s dynamic equations in the impact phase are derived based on the contact constraints method, in a differential-algebraic form. Thirdly, for obtaining the initial conditions of the contact constraints method, a partition method is proposed. The flexible multibody system in the impact phase is divided into two parts, the non-contact region and the local contact-impact region. The two parts are connected by revolute joints, and there are joint constraints between the two parts.In the initial moment of the impact phase, the impulse-momentum method is used once for the local contact-impact region to get the initial conditions of impact, and the coefficient of restitution is set to be 0.With this method, the kinematic conditions after adding contact constraints are satisfied, and the problem that the energy loss is too large due to using the impulse-momentum method is avoided.Finally, the impact dynamic simulation for a flexible multibody system with a single flexible beam is carried out. The dynamic response of the system is presented, and the feasibility of the method given in this paper is verified.