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 of SH-wave scattering by interface radial cracks with arbitrary finite lengths on a circular cavity in piezoelectric bimaterials was investigated in the present paper, and the solution of dynamic stress intensity factor at the crack tip was given. Firstly, a pair of coupled Green functions on the elastic displacement and the electric potential which were suitable for the present problem was constructed. Secondly, the infinite piezoelectric bimaterials were divided into two semi-infinite media. Based on the crack-division technique and the continiuty condition at the interface, two half spaces were bonded to infinite whole space. Thirdly, integral equations for the solution of the unknown stresses, which were related to dynamic stress intensity factor at the crack tip, were established. Finally, some examples and results for dynamic stress intensity factor (DSIF) of the radial cracks on a circular cavity were given, and the influence of a circular cavity on DSIFs at the crack tip was discussed.