基于LS-DYNA的桥墩撞击动力响应及影响因素分析

Analysis of Dynamic Response and Influencing Factors of Pier Impact Based on LS-DYNA

为探究落石撞击桥墩时主墩力学行为,使用LS-DYNA建立多种工况下的撞击模型,对撞击全过程、速度变量及竖向荷载力等因素作用下的结构动态响应、作用机理及损伤程度进行分析。研究表明:落石撞击钢筋混凝土柱过程中,碰撞作用点位置为动态变化过程,同时由于材料局部的变形,撞击能量出现较大波动,且撞击能量随着撞击速度增大而增大,混凝土材料受撞后失效由点至线最后扩展成面,能量也由撞击点逐步扩散;在竖向荷载力作用下,钢筋混凝土柱撞击力峰值有降低的趋势,但撞击位移并无明显的改变。

In order to explore the mechanical behavior of the main pier when the falling rock hits the bridge pier,LS-Dyna is used to establish an impact model under a variety of working conditions,and the dynamic response and mechanism of the structure under the effects of the entire impact process,velocity variables and vertical load force And the degree of damage is analyzed.Studies have shown that during the process of falling rocks impacting reinforced concrete columns,the location of the impact point is a dynamic change process.At the same time,due to the local deformation of the material,the impact energy fluctuates greatly,and the impact energy increases with the increase of the impact speed.After the impact,the failure extends from a point to a line and finally expands into a surface,and the energy gradually diffuses from the impact point;under the action of the vertical load,the peak impact force of the reinforced concrete column has a tendency to decrease,but the impact displacement does not change significantly.