压电体中孔边Ⅲ型界面裂纹的动应力强度因子

采用Green函数法研究界面上含圆孔边界径向有限长度裂纹的两半无限压电材料对SH波的散射和裂纹尖端动应力强度因子问题.首先构造出具有半圆型凹陷半空间的位移Green函数和电场Green函数,然后采用裂纹"切割"方法构造孔边裂纹,并根据契合思想和界面上的连接条件建立起求解问题的定解积分方程.最后作为算例,给出了孔边界面裂纹尖端动应力强度因子的计算结果图并进行了讨论.

DYNAMIC STRESS INTENSITY FACTOR FOR INTERFACIAL CRACKS OF MODE III ON A CIRCULAR CAVITY IN PIEZOELECTRIC BIMATERIALS

Based on the method of Green's function, the problem ofSH-wave scattering by interface radial cracks with arbitrary finite lengthson a circular cavity in piezoelectric bimaterials was investigated in thepresent paper, and the solution of dynamic stress intensity factor at thecrack tip was given. Firstly, a pair of coupled Green functions on theelastic displacement and the electric potential which were suitable for thepresent problem was constructed. Secondly, the infinite piezoelectricbimaterials were divided into two semi-infinite media. Based on thecrack-division technique and the continiuty condition at the interface, twohalf spaces were bonded to infinite whole space. Thirdly, integral equationsfor the solution of the unknown stresses, which were related to dynamicstress intensity factor at the crack tip, were established. Finally, someexamples and results for dynamic stress intensity factor (DSIF) of theradial cracks on a circular cavity were given, and the influence of acircular cavity on DSIFs at the crack tip was discussed.