作　　者： ; ; ; ;

机构地区： 大连理工大学水利土木学院

出　　处： 《工程力学》 2009年第9期237-243,共7页

摘　　要： 采用复变函数和保角变换的方法分析了压缩作用下脆性材料内张开型裂纹闭合变形规律,在此基础上,提出的裂纹闭合载荷简化求解公式,并进行了误差分析,分析表明采用简化公式计算结果和前人提出的理论解结果相差不大,但大大简化了计算,便于应用。并参照现有的试验,采用有限元法对压缩作用下的张开型裂纹的闭合过程进行了数值模拟,数值结果表明:张开型的椭圆裂纹面在压缩作用下要么完全闭合,要么完全张开,不存在中间状态,验证了以上的闭合规律;通过对有限元模型的节点位移变化规律的分析,提出了采用数值求解裂纹闭合载荷的方法,并将数值计算结果和理论解及简化解进行了对比分析,三者吻合很好,验证了闭合载荷简化求解方法的可靠性。 The theory on the closure deformation of the elliptical crack surface in brittle materials under compressive loadings is studied by the method of complex functions and conformal transformations. Based on the theory, a simplified formula is established to determine the closing stress of an open crack. Comparisons of the closing stress between the simplified formula and previous theory are made, and the result shows that only small error happens by using the simplified formula, which verifies the validity of the simplified formula. Referring to the experiments, the finite element method is used to simulate the closing process of the open crack under compression, and the numerical results support the theoretical viewpoints in the paper： an open crack exists only in the state of being completely closed or completely open under compression. Based on the analysis of the displacement curves of the nodes in the finite element model, a new numerical method is presented to determine the closing stress of an open crack. Finally, the closing stresses solved separately by the numerical method, the previous theoretical formula and the simplified formula are compared, and the result shows that the closing stresses obtained by the three methods are identical, which supports the proposed conclusion in the paper.

关 键 词： 断裂力学 闭合判据 数值模拟 压缩作用

领　　域： [理学] [理学] [机械工程]