IIPG Fracture:

Incomplete Interior Penalty Galerkin Method for Modeling Brittle Fracture Propagation

IIPG_Fracture is a numerical tool for modeling crack propagation in brittle materials. It combines interface-oriented finite elements with cohesive zone models to simulate material failure. The tool uses the Incomplete Interior Penalty Galerkin (IIPG) method and an extrinsic cohesive law within the MOOSE framework.

The discontinuous Galerkin (DG) finite element method offers an innovative approach for modeling brittle crack propagation. It uses zero-thickness interface elements that can incorporate extrinsic cohesive laws, eliminating the need for artificial compliance in intrinsic cohesive models. However, robust formulations and implementations of DG methods are important for addressing convergence and instability issues during crack nucleation and propagation.

This code presents a modified robust interface element formulation based on the IIPG method. It avoids initial interface penetration across elements before crack nucleation, reducing instability issues when cracks open. Verification and validation were performed using a bar tension test and a beam fracturing benchmark. The proposed method demonstrated its robustness in a micromechanics fiber/matrix debonding problem with 64 fibers embedded in a bulk matrix.

Manufacturing industries that work with composite materials can use this code with the open-source MOOSE software. By following the provided procedures and example scripts, they can create finite element models to analyze stress related to brittle failure. This code is notable for its use of the IIPG method and the incorporation of a more physically-based extrinsic cohesive law within the discontinuous Galerkin framework. It offers a reliable solution for solving material failure problems.