针对梁杆碰撞问题,通过推导物理坐标和模态坐标下的动力学控制方程,采用黏结接触模型和单轴压缩局部接触模型处理碰撞产生的接触约束,提出一种适用于梁杆碰撞激发瞬态波传播研究的动态子结构模型.与理论解的比较表明,该动态子结构模型具有良好的数值收敛性和较高的计算精度.数值计算结果显示,该模型能够有效地分析碰撞激发的杆中轴向波和梁中弯曲波的传播、反射和相互干涉.借助该模型,分别研究轴向波和弯曲波通过碰撞接触约束的传播效应,研究结果表明,柔性构件碰撞的一个显著特征是波传播效应直接影响碰撞力响应,并使碰撞力响应形式变得异常复杂.
A dynamic substructure model is presented to investigate the propagations of the transient waves generated by a beam impacting against a rod. The dynamic governing equation is derived in physical coordinates and modal coordinates. Both the adhesive contact model and the local contact model of uniaxial compression are applied to simulate contact constraints. By the comparison with the theoretical solution, the present dynamic substructure model is shown to be convergent in numerical calculation and of high numerical precision. The numerical results of the bending waves along the beam and the longitudinal waves along the rod have proven that the dynamic substructure model is valid in depicting wave propagation characteristics, such as wave propagation, wave reflection and wave interaction. Furthermore, the model is applied to simulate the bending and longitudinal waves travelling across the contact constraint, and the simulations illustrate that the impact force response is influenced significantly by the wave propagations of both the bending wave and the longitudinal wave. It might be an important reason of the complicated variations of impact force response.