网架结构在山体滑坡冲击下的垮塌模拟分析

Collapse simulation of grid structure under landslide impact

针对某网架受到山体滑坡作用导致局部垮塌的实际案例,基于Hamilton原理,运用ANSYS/LS-DYNA动力分析软件,建立起网架结构和山体滑坡冲击荷载模型,充分考虑了冲击荷载的动力效应和接触碰撞理论,定义了结构失效的限值和失效模式。通过改变山体滑坡冲击荷载的质量与速度,分析了结构失效部位的能量变化、速度和位移演变、等效应力和塑性应变的开展。结果表明:在冲击荷载下网架杆件所能承受的瞬时应力可以远大于在静力荷载下杆件的屈服应力,网架在被冲击区域绝大部分杆件进入塑性,非冲击区进入塑性的杆件多发生于横向的上弦杆和下弦杆;通过对塑性杆件的加固处理,有效增强了结构的抗倒塌能力。

For the actual case of a partial collapsed grid caused by landslides,this article is based on Hamilton’s principle,using the ANSYS/LS-DYNA dynamic analysis software to establish the grid structure and landslide impact load model,considering the dynamic effects of impact loads and contact collision theory fully and defining structural failure limits and failure mode.By changing the mass and velocity of the landslide impact load,the energy change,velocity and displacement evolution,equivalent stress and plastic strain of the structural failure site are analyzed.Then,the key failure sites of the grid under the impact load of the landslide are obtained,and thefeasibility of the reinforced design of the key bars against the impact collapse is indicated.The simulation analysis in this paper has certain guiding significance for the anti-slump design of similar projects.