三维裂纹体的断裂分析

采用等参奇性边界单元法求解了三维裂纹体的复合型应力强度因子，并采用Ｆｏｒｍａｎ模型，模拟了三维裂纹体疲劳断裂过程，预估了在等幅和变幅载荷作用下的三维裂纹体的疲劳寿命。文中给出了两个数值算例，其计算值与试验结果比较表明，提出的方法与程序可满足工程分析要求。

Fractural Analysis of Three Dimensional Cracked Body

Evaluation of fracture toughness and estimation of fatigue life for a comp- licated cracked body are very difficult. It is usually impossible to use in com- mon fracture analysis for complicated cracked body. In this paper, a special formulation of 3-D crack boundary element considering stress and strain singu- larity properties at the crack tip is presented and fatigue life for 3-D cracked bodies under cyclic loading is studied, based on the Forman's model. A computer code for fracture analysis of 3-D cracked bodies with surface flaw or/and embedded crack has been developed. Computational results are compared with those obtained by experiments. Their good agreement shows that the boundary element formulation and the method of estimation for fatigue life pro-vided in this paper are very satisfactory for engineering analysis.