柔性杆多次撞击过程的瞬态动力学分析

对双柔性杆多次撞击过程,采用St.VENANT杆波动理论,提出应用瞬态波函数特征值展开法,分别求解多次撞击和分离过程瞬态波响应理论解.应用该理论解,由撞击过程中两杆组合结构的撞击界面应力,计算多次撞击力响应,从而实现了对多次撞击问题的分析.数值计算表明,该方法可以合理的分析多次撞击过程,较精确的计算多次撞击力响应和结构瞬态波响应,并可进一步研究"次撞击"和瞬态波传播等物理现象,以及研究系统参数对多次撞击过程的影响.研究结果可为柔性结构多次撞击过程的瞬态响应分析和结构安全评估提供参考.

Transient Dynamics Analysis for Multiple-impact of Flexible-rods

The problem of the multiple impacts of double flexible rods is studied. The theoretical solutions of the transient wave responses of the two rods are obtained for the processes of impacts and separations, based on the expansion of transient wave functions in a series of eigenfunctions for the St. VENANT rod. The multiple-impact force is derived from the interfacial stress at the contact ends. The interfacial stress is calculated from the solutions of the transient wave response of a temporary combined rod system during impacts. Therefore, the problem of the multiple impacts of double flexible rods is solved reasonably. The numerical results show that the effects of the transient wave propagation induced by impacts are fully considered. The present solution can obtain the multiple-impact force responses and the transient wave responses. The phenomenon of the transient wave propagation and the "sub-impact" can be found numerically as well. The effects of the initial impact velocity on the impact responses are investigated, and the numerical results show that there are some complex physical mechanisms on the multiple impacts. It is shown that the present solution can simulate reasonably the processes of multiple impacts, and the solution methods can be applied to the multiple-impact phenomena taken place in wider flexible mechanical systems.