摘要
本文采用一种类似于差分方法的集中质量有限元模型和人工边界透射理论分析倾斜成层弹性半空间中瞬态SH波的近场波动问题。文中对采用的有限元模型和波源的处理方法作了细致的描述,导出了各类节点的位移计算公式。对一种单斜层-半空间模型进行了数值计算。数值结果与广义射线法结果一致。此外,本文分析了倾斜层尖端区域的衍射效应,提供了该区域的数值结果。最后,本文对数值计算中的寄生振荡问题进行了探讨。
In this paper, a finite element method with lumped mass formulation is applied to analyse the transient SH wave propagation in an elastic half-space with a dipping layer. Firstly, a minute description of the applied finite element formulation and the method to handle the wave source are given inthe paper, and the formulas for calculating the displacements of various kinds of nodes are derived, Secondly, the numerical calculation of a single dipping layer half space model is carried out, and it shows that the numerical results are in accordance with the results obtained by the generalized ray method. Additionally, the diffraction effect of the edge area of dipping layer is analysed in this paper, and the numerical results of this area are obtained , which have not been found at home and abroad so far. Finally, the problem of spurious oscillations in calculation is discussed.
