Abstract An implementation of the coupled criterion (CC) for crack initiation simulation in the commercial finite element (FE) code Abaqus/Standard is proposed. This finite fracture mechanics approach allows crack initiation to be modeled by fulfilling simultaneously a stress and an energy conditions, which results in the determination of the loading level and crack length at initiation. Two procedures are considered and compared: the first one relies on matched asymptotic expansions while the second one is based on full FE calculations. The asymptotic approach is computationally more efficient than the second one since it requires less calculations to be performed. However, it is restricted to cases for which the crack initiation length remains small compared to the smallest characteristic dimensions of the studied structure. For such cases, both methods leads to similar results as illustrated by crack initiation modeling of notched specimen under three point bending. The provided source codes and the tutorials help understanding and applying the CC for crack initiation modeling.

中文翻译：

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耦合准则的数值实现：匹配渐近和全有限元方法

摘要 提出了在商业有限元 (FE) 代码 Abaqus/Standard 中实现裂纹萌生模拟的耦合准则 (CC)。这种有限断裂力学方法允许通过同时满足应力和能量条件来对裂纹萌生进行建模，从而确定开始时的加载水平和裂纹长度。考虑并比较了两个过程：第一个过程依赖于匹配的渐近展开，而第二个过程基于完整的有限元计算。渐近方法在计算上比第二种方法更有效，因为它需要执行的计算更少。然而，它仅限于裂纹起始长度与所研究结构的最小特征尺寸相比仍然很小的情况。对于此类情况，如三点弯曲下缺口试样的裂纹萌生模型所示，这两种方法都会导致类似的结果。提供的源代码和教程有助于理解和应用 CC 进行裂纹萌生建模。