Abstract: The impact dynamics of a flexible beam with large overall motion is investigated. The dynamic equations in three periods (before, during, and after impact) are established respectively. Based on the rigid-flexible coupling dynamic theory of flexible multibody systems, the dynamic equations of the flexible beam without impact are established. A method for solving the impact dynamics is proposed, combined the impulse-momentum method and the contact constraint method. The impulse-momentum method is used to achieve kinematic transform, and the contact constraint method is used to solve the impact process. The system’s impact dynamic equations are obtained, and the contact/separation criterion is given to realize the kinematic transform and dynamic solution. The simulation program is developed, and the dynamic response in different periods of a simulation example is given. It is shown that the impact solving method given can calculate the flexible multibody system’s impact problem conveniently. The flexibility, the large overall motion, and the impact effect are coupled. And the impact makes great influence on the flexible multibody system’s global dynamics during and after the impact process.

Key words: Contact constraint method, Flexible multibody system, Impact, Impulse-momentum method, Large overall motion