Abstract A finite element-based method for accurately determining stress intensity factors (SIF) for interacting arbitrarily-shaped 3D cracks is proposed. The method utilizes the superposition principle and does not require fine meshes or singular elements. The foundation of the new method is that disturbances in an elastic stress field due to neighbouring cracks can be captured accurately by splitting the total stress at the crack tip element into two components, singular and non-singular terms. Computed results are in very good agreement with the existing numerical solutions. In addition, novel SIF solutions for various crack configurations are presented, and the conversion of size-independent solutions to the small crack model, the √area parameter model, is introduced. The proposed method can be applied to the SIF analysis for interacting cracks with various shapes often observed e.g. in additively manufactured (AM) components and the solutions will be useful for the standardization for such complicated defect configurations.

中文翻译：

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一种有效的任意形状3D裂纹相互作用应力强度因子评估方法

摘要 提出了一种基于有限元的方法，用于准确确定相互作用的任意形状 3D 裂纹的应力强度因子 (SIF)。该方法利用叠加原理，不需要精细网格或奇异单元。新方法的基础是通过将裂纹尖端单元处的总应力分为奇异项和非奇异项两个分量，可以准确地捕获由于相邻裂纹引起的弹性应力场中的扰动。计算结果与现有的数值解非常吻合。此外，还介绍了针对各种裂纹配置的新型 SIF 解决方案，并介绍了将与尺寸无关的解决方案转换为小裂纹模型、√area 参数模型。