Coupling of a phase-field method with a nonlocal micro-mechanical damage model for simulating ductile fracture

We present a nonlocal phase-field framework aimed at modeling ductile fracture using a extended Gurson-type model. Both the intervoid necking and the void shearing mechanisms are introduced into the crack driving force for the phase-field evolution. Different from the conventional Gurson-type models, void coalescence is considered by a modified phenomenological function of the nonlocal damage introduced via a thermodynamic approach. In this paper, firstly, we detail the numerical implementation of the nonlocal regularization of the extended Gurson-type model and the phase-field model into the commercial software (e.g., ABAQUS), wherein several user interfaces are used in combination. Then, we present several numerical benchmark examples of ductile fracture under tension, shear, and mixed mode loadings in order to illustrate the predictive ability of the proposed model. After systematic experimental verification, the nonlocal simulations presented adequately demonstrate that the pathological mesh-dependency and the transferability problem are alleviated using the current model.

Automated summary

We present a nonlocal phase-field framework for modeling ductile fracture using an extended Gurson-type model. The model considers both intervoid necking and void shearing mechanisms in the crack driving force for phase-field evolution. By introducing a modified phenomenological function of nonlocal damage via a thermodynamic approach, void coalescence is considered. Numerical implementation of the model in commercial software (e.g., ABAQUS) is discussed, and several numerical benchmark examples are presented to demonstrate the predictive ability of the proposed model. Experimental verification shows that the current model alleviates the issues of pathological mesh-dependency and transferability.