一弹性层覆盖于半无限弹性介质对表面点冲击载荷的瞬态响应

TRANSIENT RESPONSES OF AN ELASTIC LAYER OVERLAYING AN ELASTIC HALF SPACE SUBJECTED TO DYNAMIC CONCENTRATED LOAD AT THE SURFACE

利用广义射线理论,研究了一弹性层覆盖于半无限弹性介质表面受法向动集中荷载作用情形表面处的位移响应.给出了一种计算瞬态响应的有效方法,首先根据反射次数的不同将射线自动分组,然后将同一组中具有相同积分路径的积分式自动合并并一次性完成积分.运用该技术,计算量大大减少,使得广义射线法应用于较长时间响应计算的工作得到推进.数值结果中给出了两种情形位移响应的特点,一种情形是弹性层比半空间层硬,另一种情形是弹性层比半空间层软.

The transient displacement responses at the surface of an elastic layer overlaying an elastic half space subjected to a dynamic concentrated normal load at the surface are studied by means of the generalized ray theory. An effective way for computing the transient response is developed. The rays are automatically divided into several sub-groups according to number of the refraction and then in each sub-group and the ray integrations with the same integral paths are incorporated automatically and executed only once. By utilizing the present technique, the computation cost for the transient responses is greatly decreased and the numerical realization of the generalized ray theory for long history responses is then enhanced. In the numerical analysis, the behaviors of the transient displacement response for two cases are analyzed. One is that the elastic layer is harder than the half space and the other is that the elastic layer is softer than the half space.