An efficient stress intensity factor evaluation method for interacting arbitrary shaped 3D cracks

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.