Interacting micro-cracks near the tip in the process zone of a macro-crack
Interacting micro-cracks near the tip in the process zone of a macro-crack
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DOI：
10.1016/0022-5096(87)90019-6
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发表时间：
1987
影响因子：
5.3
通讯作者：
M. Hori;S. Nemat-Nasser
中科院分区：
文献类型：
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作者：
M. Hori;S. Nemat-Nasser
对于含有两个或两个以上的复杂几何裂纹、空洞和其他相互作用缺陷的线性弹性各向同性固体，horand Nemat-Nasser（1983,1985a）最近提出了一种称为“伪牵引力法”的方法，当具有尖角的裂纹或空洞相距适当远时，该方法可以有效地解决这类二维问题。然而，当裂纹或空腔非常靠近另一个裂纹的尖端时，这种方法就失效了，这是在裂纹尖端的加工区域包含许多微裂纹的情况。在这项工作中，伪牵引力方法的修改被引入，这将允许有效地计算应力强度因子时，大裂纹相互作用的小裂纹位于非常接近其尖端在其过程区。得到了宏观裂纹的应力强度因子和微裂纹的应力强度因子的渐近表达式。结果表明，在远场静水张力作用下，微裂纹在宏观裂纹加工区内的存在也会诱发面外裂纹扩展。给出了几个说明性的例子，包括存在精确解的两个共线裂纹，得到了很好的相关性。
Foralinearlyelastic and isotropic solid containing two or more cracks, cavities and other interacting defects of complex geometries, a method called “the method of pseudo-tractions” has been recently proposed by Horiand Nemat-Nasser(1983, 1985a), which can effectively solve two-dimensional problems of this kind, when cracks or cavities with sharp corners are suitably far apart. The method, however, breaks down when a crack or cavity is situated very close to the tip of another crack, which is the case when the process zone at the tip of a crack contains many micro-cracks.In this work, modifications of the method of pseudo-tractions are introduced, which will permit effective calculation of the stress intensity factors when a large crack interacts with small cracks which are situated very close to its tip in its process zone. Explicit asymptotic expressions are obtained for the stress intensity factors of the macro-crack, as well as those of the micro-cracks. It is shown that the presence of the microcracks in the process zone of a macro-crack may induce out-of-plane crack growth even under far-field hydrostatic tension. Several illustrative examples are worked out, including two collinear cracks for which an exact solution exists, arriving at an excellent correlation.