热、机械载荷作用下夹杂对应力强度因子的影响

推导了远场应力、热应力耦合作用下含夹杂裂纹体的应力强度因子求解公式，改进了体积力法中的裂纹面合力平衡条件，将应力强度因子的求解归结为解一组积分方程，再将积分方程转化为线性方程组进行数值求解。算例分析结果表明方法正确、有效。将该算法应用于含Al2O3夹杂的FGH95材料应力强度因子分析中，计算结果表明热应力对应力强度因子影响很小。

Effect of inclusion on the stress intensity factors under mechanical and thermal loads

The interaction between a round inclusion and a crack under thermal and remote mechanical loading is analyzed based on the body force method(BFM).The traction-free condition on the crack line is mended so that the couple effect of thermal and remote mechanical loading could be taken into account and the accuracy could be improved.The traction-free condition can be expressed by a series of integral equations which can be discretized to a set of linear equations and then it can be solved easily.Stress intensity factors(SIF) are gotten through the root of the linear equations.The calculation results in this paper is compared to that in other references to validate the method and program.The comparison shows the method and program in this paper have the characters of higher accuracy and higher solution speed.The method is used to the problem of interaction between the crack and an Al_2O_3 inclusion in the material of FGH95 PM superalloy under various thermal and remote mechanical loadings.The results show that thermal load has little effect on SIF,whereas the mechanical load is a dominant factor.The reason is the difference of thermal expansion coefficient between Al_2O_3 and FGH95 is not big and the elastic modulus of Al_2O_3 is very small.