Simulation of dynamic fracture in quasi-brittle materials using a finite element modeling approach enhanced by moving mesh technique and interaction integral method

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This work presents an efficient modeling approach for predicting dynamic crack propagation mechanisms in quasi-brittle materials. The proposed method consists of a standard Finite Element code enhanced by Moving Mesh (MM) technique consistent with the Arbitrary Lagrangian-Eulerian (ALE) formulation. The MM is used to reproduce the geometry evolution caused by dynamically growing cracks. More precisely, the nodes of the computational mesh around the crack tip change position during the simulation consistently with the growth of the crack front. In such a context, the ALE formulation ensures an effective re-location of mesh nodes inside the computational domain, reducing the overall amount of remeshing events. The motion of the computational mesh takes place according to previsions dictated by classic fracture criteria, which define crack initiation conditions, the direction of propagation, and the velocity of the advancing crack front. Such conditions depend on Dynamic Stress Intensity Factors at the crack front. Hence, accurately predicting these fracture variables is mandatory to ensure consistent mesh motions. To this end, the proposed approach implements the ALE formulation of the M-integral, which enables computing fracture variables on moving elements without losing accuracy. The validity of the proposed modeling strategy has been assessed through comparisons with numerical data and analytical formulations reported in the literature.