This paper presents the calculation of complex stress intensity factors (K) for interface cracks in commonly used bi-material specimens subjected to arbitrary ununiform stress fields. First, detailed finite element analyses were carried out for cracks in centre-cracked plate (CCP) and single edge-cracked plate (SECP) bi-material specimens of different material combinations under non-uniform stress distributions. The complex SIFs were determined for the loading cases of uniform, linear, parabolic or cubic stress distributions applied to the crack faces in both normal and shear directions. Then, general mathematical forms of the two complex crack face weight functions for interface cracks, one for normal loading, and one for shear loading, have been formulated by taking advantages of the knowledge of specific analytical complex weight functions available in the literature, and certain properties of the complex weight functions in general. The existence of the general functional forms simplifies the determination of these weight functions for specific crack geometrical configurations and bi-material combinations. The determination of a specific weight function is thus reduced to the determination of the unknown parameters of the generalized weight function functional forms. It was demonstrated these unknown parameters can be determined from reference stress intensity factors. This method was used to derive the complex weight functions for interface cracks in bi-material CCP and SECP specimens. The derived closed-form weight functions were then validated against complex stress intensity factors solutions for several non-linear normal and shear stress distributions.

本文介绍了常见双材料试样在任意不均匀应力场作用下界面裂纹的复合应力强度因子（K）的计算方法。首先，在应力分布不均匀的情况下，对不同材料组合的中心裂纹板（CCP）和单边缘裂纹板（SECP）双材料试样中的裂纹进行了详细的有限元分析。确定了在法向和剪切方向上均施加于裂纹面上的均匀，线性，抛物线或三次应力分布的载荷情况下的复杂SIF 。然后，针对界面裂纹的两个复杂裂纹面权重函数的一般数学形式，针对正常裂纹的一个加载，一个用于剪切通过利用文献中可获得的特定分析复杂权重函数的知识以及通常具有的复杂权重函数的某些特性来制定载荷。通用功能形式的存在简化了针对特定裂纹几何构型和双材料组合的这些权重函数的确定。因此，特定权函数的确定被简化为广义权函数函数形式的未知参数的确定。已证明可以从参考应力强度因子确定这些未知参数。该方法用于导出双材料CCP和SECP试样界面裂纹的复权函数。