Adaptive fourth-order phase-field modeling of ductile fracture using an isogeometric-meshfree approach

The fourth-order phase-field modeling of ductile fracture in elastic-plastic materials is performed via an adaptive isogeometric-meshfree approach. In the developed phase-field model, the total energy functional consists of the elastic contribution and the dissipated contribution because of fracture and plasticity. The coupling of the plasticity to fracture is implemented by a degradation function that is applied to the elastic energy. The present fourth-order phase-field model is capable of relaxing the mesh size requirements while accurately regularizing sharp cracks. To further enhance the computational efficiency, the isogeometric-meshfree approach is adopted for the numerical implementation of the phase-field model within a staggered computational framework. The developed approach can flexibly implement the C1-continuity of a crack phase field that is required by the fourth-order model. Moreover, an adaptive mesh refinement strategy is developed, which includes the gradient-based refinement indicators and the field transfer operators. Numerical simulations of a series of representative cases show that the developed fourth-order model can accurately and efficiently capture complex ductile fracture patterns including plastic localization, crack initiation, propagation, and merging, which demonstrates the reliability of the adaptive fourth-order phase-field modeling of ductile fracture. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, a fourth-order phase-field modeling of ductile fracture in elastic-plastic materials is conducted using an adaptive isogeometric-meshfree approach. The developed model includes the elastic contribution and the dissipated contribution due to fracture and plasticity in the total energy functional. The coupling between plasticity and fracture is achieved through a degradation function applied to the elastic energy. The model is capable of accurately regularizing sharp cracks while relaxing the mesh size requirements.