Analysis of generated shear wave due to stress discontinuity in a monoclinic layered structure

Abstract

The present study articulates the generation of SH-wave due to sudden stress discontinuity which moves at the monoclinic crustal layer of finite thickness overlying a monoclinic half-space. Free surface displacement field are obtained in exact form by the method due to Cagniard which is modified by De Hoop for different cases of stress discontinuities at the interface of the layered structure, i.e. when the stress discontinuity is created at certain point and then expands with uniform velocity U in z-direction (i.e. Case I); when a dynamic region of discontinuous stress moves with uniform velocity (i.e. Case II); when the stress discontinuity is created in a static region and then expands with uniform velocity (i.e. Case III); and when an impulsive stress discontinuity occurs only at point z = Ut (i.e. Case IV). The numerical calculations and graphical illustrations have been carried out in order to reveal the effect of anisotropy (monoclinic and transversely isotropic) on the free surface displacement field which give some peculiar results and serve as major highlights of the present study. Additionally, as a special case, the deduced results are matched with the isotropic case, which validates the undertaken work.