楔形空间中任意形状孔洞对平面SH波的散射：IBEM求解

SOLVING THE SCATTERING OF PLANE SH-WAVES BY AN ARBITRARY SHAPED CAVITY EMBEDDED IN A WEDGE-SHAPED SPACE BY IBEM

采用间接边界元法(IBEM),求解了楔形空间中任意形状孔洞对平面SH波的散射问题.基于单层位势理论,首先在孔洞表面及其附近楔形空间表面上施加虚拟均布荷载,以构造散射波场.进而由自由表面零应力条件,建立方程求解得到虚拟荷载密度.总波场由楔形空间自由波场和散射波场叠加得到.研究表明:IBEM方法能够精确高效求解楔形空间中弹性波散射问题.楔形空间孔洞对波的散射特征依赖于波入射角、无量纲入射波频率、楔形夹角、孔洞位置及其形状;孔洞周围波的相干效应十分显著,空间表面位移幅值及孔边动应力集中因子比半空间情况放大一倍有余,分别达到8.5和10.0;该研究为楔形空间中更为复杂的P、SV波散射问题求解奠定了基础.

The scattering of plane SH waves by an arbitrary shaped cavity in a wedge-shaped space is investigated by using the indirect boundary element method （IBEM） in this contribution. According to the theory of single-layer potential,the scattering wave field can be constructed by applying virtual uniform load on the free surfaces of cavity and the wedge-shape space. Then the density of virtual load can be solved by applying the zero-stress condition on the free surfaces. The total wave field is obtained by the superposition of free-wave field and scattering-wave field in wedge-shaped space,indicating that the IBEM can solve accurately and efficiently the diffraction of elastic wave in wedge shaped space. Results show that （1） the scattering of waves depends on the angle of incidence, the frequency of the incident wave, the shape and location of cavity and the angle of the wedge; （2） the waves interface effect around the cavity in wedge space seems more significant, and the wedge space surface displacement amplitude and stress concentration factor on cavity surface can reach 8.5 and 10.0 respectively which are twice more than that of the case of half space. This study provides a potential method to analyze the scattering of P and SV waves in wedge-shaped space.