Dynamic brittle fracture by XFEM and gradient-enhanced damage
Résumé
A combined continuous-discontinuous approach to fracture is used to model crack prop- agation under asymmetric dynamic loadings. A gradient-enhanced damage model is utilized to evaluate degradation of the material in the process zone. This type of model avoids mesh dependency and pathological effects of the local damage models. A damage-based criteria is utilized for crack propagation. In this framework, crack propagation occurs as a result of material softening and degradation in the process zone in front of the crack. As damage reaches its critical value, by using the extended finite element method (XFEM) a discon- tinuous crack is introduced within the damage band. An operator-split approach is used to solve the problem. Finally a brittle fracture case is modeled to show the capabilities and robustness of the employed approach.