Abstract: A multiple contact impact separation (MCIS) method which combines the local elastic-plastic contact model with the finite difference method is proposed for the research of beam ― beam multiple elastic-plastic impact problem. The uniaxial compression elastic-plastic contact deformation model is applied in the multiple elastic-plastic loading and unloading process, and finite difference method is adopted to solve dynamic equations, so as to completely simulate each elastic-plastic impact in the whole orthogonal impact process between a free beam and a simply supported beam. Through comparison to the ideal rigid plastic model and the three-dimensional finite element method (FEM), it is shown that the calculation result of MCIS method is reliable and its calculation efficiency is high. It is found that the multiple elastic-plastic impact phenomenon between the beams is caused by the response of impact deformation, and it is the result of intercoupling of local contact deformation and global structure deformation, which has an obvious characteristic of divided region of impacts. Comparing to the first impact, the impact force, impact impulse and impact energy loss of subsequent impacts are significant. Hence, sufficient attention should be paid to the phenomenon of multiple elastic-plastic impacts of flexible structure.

Key words: Beam, Elastoplasticity, Energy dissipation, Multiple-impact, Transient analysis