基于LS-DYNA的墩柱碰撞动力响应仿真分析研究

Simulation and Analysis of Dynamic Response of Pier Column Impact Based on LS-DYNA

为研究山区桥梁墩柱遭受落石撞击的力学性能。基于ANSYS/LS-DYNA软件建立墩柱撞击有限元分析模型,通过分析撞击点处材料单元的速度、应力时程结果以及墩底最大主应力云图损坏情况,得出碰撞过程中墩柱在冲击荷载作用下的响应及规律。分析结果表明:撞击荷载作用初期,墩柱混凝土材料迅速开裂,撞击点处材料运动速度与撞击体基本一致;碰撞初期能量较大,材料失效过程短,通过耗能装置可以在一定程度上降低碰撞破坏的程度;墩柱顶部与底部在碰撞前期呈现一侧受拉,一侧受压状态,且受拉面存在一定的开裂趋势,在进行墩柱防护措施时,墩顶、底防护需予以一定的重视。

In order to study the mechanical properties of bridge pier columns in mountainous areas under the impact of falling rocks.Based on ANSYS/LS-DYNA software,the finite element analysis model of pier column impact is established.Through analyzing the velocity and stress time history results of the material element at the impact point and the damage of the maximum principal stress nephogram at the pier bottom,the response and law of the pier column under the impact load during the impact process are obtained.The results show that at the initial stage of the impact load,the concrete material of the pier column cracks rapidly,and the material movement speed at the impact point is basically consistent with that of the impact body;At the initial stage of collision,the energy is large and the material failure process is short.The degree of collision damage can be reduced to a certain extent through energy consumption devices;At the early stage of collision,the top and bottom of the pier column are under tension on one side and pressure on the other side,and the has a certain tendency to crack.When taking protective measures for the pier column,attention should be paid to the protection of the pier top and bottom.