公路隧道冲击响应的2D有限元分析

2D finite element analysis of the impact response of a highway tunnel

在有限元计算中,为了保证网格划分的合理性,提高计算的精度,结合自主研发的结构分析软件系统SASS,提出了一种生成曲边有限元网格的有效方法,以变比例的方式综合考虑大单元各边节点对内部各对应点坐标的影响.对某公路隧道横截面建立了平面应变状态下的有限元模型,考虑冲击荷载在不同速度和作用时间的影响下,对其进行动位移、速度和加速度的分析.结果表明:在相同的冲击速度下,冲击荷载作用时间越长,引起隧道壁上的最大位移值越小;当冲击荷载作用时间相同时,在不同冲击速度下,同一点到达各自最大位移值的时刻相同;在冲击荷载的速度和作用时间相同的情况下,各控制点位移、速度和加速度都呈同步周期性变化.

To ensure the rationality of the grid and to improve the calculation accuracy in finite element analyses,an effective method is proposed for generating a mesh with curved edge elements by combining with a self-developed structural analysis software system（SASS）.In this method,the effect of the edge nodes of each large element on the corresponding internal coordinates is taken into account in a variable proportional manner.A finite element model of the plane strain state is established for the cross section of a highway tunnel.Considering different load velocities and load times,the displacement,velocity and acceleration are calculated.The results show that at a given load velocity,the longer the time of the impact load is,the smaller the maximum displacement on the wall of the tunnel is.For a given loading time but different velocities,the time the maximum displacement values are reached and the corresponding moment at a given point are the same.With the same load velocity and time,the displacement,velocity and acceleration of each control point is changed synchronously and periodically.