Scattering Of SH-waves By Circular Cavity And Crack Near Orthotropic Medium Interface

Scattering of SH-waves by complex defects near interface is an important subject in elastic wave theory research.Previous studies mostly focused on more isotropic single-phase medium.Beyond the field of linear elastodynamics,this paper developes the methods of complex variable,Green's function and wave function expansion to study three types of issues: SH-wave scattering by a circular cavity and a crack in an anisotropic elastic half-sapce,a circular cavity near an anisotropic biomaterials interface,a circular cavity and a crack near an anisotropic biomaterials interface.1.Four Green functions were firstly constructed: the Green function for an out-plane harmonic line source loaded at a random point on half-space surface that contains a circular hole;the Green function for an out-plane harmonic line source loaded at a random point in a half-space surface that contains a circular hole;the Green function for an out-plane harmonic line source loaded at a random point on half-space surface that contains a circular hole and a crack;the Green function for an out-plane harmonic line source loaded at arbitrary point along a full elastic half-space surface.2.The methods of complex variable and Green's function were developed to study the SH-wave scattering by a circular cavity and a crack in an anisotropic elastic half-space.This paper starts from the calculation of the displacement field and stress field when SH-wave incidents in a orthogonal anisotropy half space.Based on the solved Green's function and“crack-division”,a crack is created to deduce the displacement field and stress field of a elastic orthogonal anisotropy half-space with a circular cavity and a crack.Thus,the analytical expressions of dynamic stress concentration factors(DSCF)around the cavity hole and dynamic stress intensity factors(DSIF)at the crack tip will be obtained.At last,a mass of numerical examples on the influence of different parameters on the DSCF around the cavity hole,dynamic stress intensity factors(DSIF)at the crack tip and displacement of the horizontal surface is discussed.3.Based on the idea of “conjunction”,the methods of complex variable,Green's function and wave function expansion were used to report the SH-wave scattered by a circular hole or a hole and a crack near an orthogonal anisotropic bimaterials interface.Thebimaterials space is divided into an elastic orthogonal anisotropic half space possessing a circular cavity(or a circular cavity and a crack)and an elastic full half space along a horizontal interface.Using the obtained Green's function,“crack-division” is applied in creating a crack.Based on continuity conditions of the interface,undetermined anti-plane forces are loaded on the horizontal surfaces for conjunction of two sections.A series of Fredholm integral equations are deduced which is solved by using the weakly singular integral equations direct discrete method.The expressions of dynamic stress concentration factors(DSCF)and dynamic stress intensity factors(DSIF)is obtained.At last,the law of different parameters influence dynamic stress concentration factors(DSCF)and dynamic stress intensity factors(DSIF)are discussed in the paper.