泥石流块石冲击下钢绞线网组合结构的动力响应模拟研究

Simulation Study on the Response the Composite Structure with Steel Strand Network Impacted by Debris Flow Boulders

针对泥石流块石冲击荷载作用下灾害的防治问题,引入钢绞线网组合结构,并利用ANSYS/LS-DYNA对不同冲击物在不同的冲击点位置、冲击物速度和冲击物质量条件下钢绞线网组合结构对泥石流块石冲击的动力响应进行数值模拟。结果表明:①冲击物在不同的冲击点位置,钢绞线网组合结构的冲击力峰值不同,同一冲击高度,钢绞线网组合结构中间点处的冲击力峰值比两侧点要小;随着冲击高度的增加,钢绞线网组合结构的冲击力峰值减小;②在低速度冲击过程中,钢绞线网组合结构中钢绞线未断裂,结构的冲击能量守恒,在高速度冲击时,钢绞线网组合结构冲击点处横向钢绞线比竖向钢绞线的塑性应变和轴向力更早达到最大,横向钢绞线先发生断裂;③钢绞线网组合结构冲击点处位移峰值分析显示,随着冲击物速度和冲击物质量的增加,钢绞线网组合结构的位移峰值增加,但位移增幅降低。

In view of the prevention of debris flow under the impact load of debris flow boulders,this paper introduces composite structure with steel strand network.The paper applies ANSYS/LS-DYNA to simulating the impact response of composite structure with steel strand network at different impact points,different impact velocity and different impact mass.The results show that:①the peak value of impact force varies with the different location of impact points,the peak value of impact force which locates at the middle impact points is smaller than the same impact height which locates at the both sides;the peak value of impact force decreases with the increase of impact height;②in the process of low-speed impact,the steel strand is not broken and the impact energy of the structure is conserved.When high-speed impact occurs,the plastic strain and the axial force of the transverse strand at the impact point reaches the maximum ealier than the vertical steel strand,and the transverse strand also breaks earlier;③the peak displacement of the structure at the impact point increases with the increase of the velocity of the impact object and the quantity of the impact object,but the displacement increment decreases.