构件跌落碰撞的数值模拟研究

Numerical simulation of component-dropping-collision

针对构件跌落碰撞问题,将Hertz-damp模型与有限元方法结合,给出了结构碰撞位移突加约束条件,建立了碰撞结构体系的动力方程。该方法能考虑碰撞体质量分布对碰撞过程的影响,同时可描述结构碰撞过程中的刚度非线性和能量损失。建立了构件跌落碰撞模型,初步分析了跌落构件质量、质量分布以及跌落高度等参数对碰撞过程的影响。研究表明:结构碰撞模拟中碰撞体质量沿接触面法线轴向不对称时应考虑其质量分布,否则会高估碰撞反应;碰撞荷载峰值和单次碰撞持续时间与跌落构件质量和跌落高度均成指数关系,碰撞荷载峰值随跌落构件质量和跌落高度增大而增大,而单次碰撞持续时间则随跌落构件质量增大而增大,随跌落高度增大而减小。这些规律能为减轻结构碰撞破坏研究提供参考。

In order to study the effect of component-dropping-collision on structural response,the constraint condition on displacement imposed by collision was derived and the dynamic equation of collision system was established.The presented method,which combines Hertz-damping model with finite element method,can account for the influence of mass distribution of components as well as the nonlinear stiffness and the energy loss during collision process.Effects of mass,mass distribution and dropping height of component were analyzed based on component-dropping-collision model.The results indicate that neglecting mass distribution of collision body will lead to overestimation of collision effects while collision body is asymmetric along the collision surface normal.The peak of collision load and the duration of single collision are exponential functions of mass and dropping height of component,and the larger the mass and the higher the dropping height,the larger will be the peak of collision load,but the duration of single collision becomes longer with the increase of mass and the decrease of dropping height.These coclusions can provide reference for reduction of collision damage.