半空间内孔边界面裂纹对SH波的动力响应

摘要

The dynamic stress responses of interface cracks originating at an hole in a half-space to SH-wave were studied using the methods of‘image’and‘partitioning-conjunction’.Firstly,the half space was imaged into a full space and a scattering wave field satisfying boundary conditions was constructed with the method of‘image’.Secondly,with the help of the ‘partitioning-conjunction’method and ‘crack-division’technique,the solving domain was divided into two parts along the interface,the two sub-domains satisfying the continuous ‘conjunction’conditions of displacement and stress on the interface were conjoined,and a group of integral equations were built to solve this problem.Finally,the dynamic stress intensity factor of the interface crack tip was analyzed with the numerical method.Numerical results demonstrated that the purpose of reducing crack tip's dynamic stress can be achieved by properly avoiding the combination of the most adverse effect factors,such as,incident wave number,incident angle,and crack length,etc.%采用“镜像”和“剖分－契合”等方法，对SH波作用下半空间孔边界面裂纹的动应力问题进行了研究。首先，采用“镜像法”，将半空间镜像为全空间，构造出满足边界条件的散射波场；其次，借助“剖分－契合”方法和“裂纹切割”技术，将全空间沿界面分割成两个半空间求解后，再由界面应力位移连续“契合”条件组合成全空间，建立起求解该问题的积分方程组；最后，对界面裂纹端点的动应力强度因子（DSIF）进行数值分析。分析结果表明：适当地避开入射波波数、入射角度及裂纹长度等最不利影响因素的组合，可达到降低裂纹尖端点动应力的目的。