Implementation of the regularized extended finite element method in Abaqus framework for fracture modeling in laminated composites

The Regularized eXtended Finite Element Method (Rx-FEM) is a fracture mechanics based technique for progressive failure simulation when multiple damage events such as matrix cracks and delamination are introduced into the finite element model via mesh independent displacement discontinuities. In the Rx-FEM, the Heaviside step function that is used in the eXtended Finite Element Method (x-FEM) is replaced by a continuous function approximated by using the FE shape functions. This regularization offers unique possibility for the implementation of the Rx-FEM methodology in commercial FE software as a superposition of native elements as opposed to a single user defined element which is the approach taken by x-FEM implementation to date. The advantages of the novel Rx-FEM implementation lie in the ability to utilize the capabilities of the host software including contact, geometric nonlinearity as well as post-processing, and visualization. The proposed implementation of the Rx-FEM methodology is illustrated for commercial software Abaqus on a number of examples of mesh-independent crack modeling in composite laminates, and delamination between plies. The validity of the proposed implementation is demonstrated by comparing with experimental data and benchmark solutions.