# Phase field modelling of crack propagation, branching and coalescence in rocks

## TL;DR

This paper introduces a phase field model implemented in COMSOL to simulate complex crack behaviors in rocks, including propagation, branching, and coalescence, validated against experimental data.

## Contribution

The paper presents a novel phase field modeling approach for rock crack analysis, incorporating strain decomposition and complex 3D crack pattern simulations.

## Key findings

- Model accurately predicts crack propagation and coalescence.
- Simulations match experimental results.
- Applicable to complex 3D crack scenarios.

## Abstract

We present a phase field model (PFM) for simulating complex crack patterns including crack propagation, branching and coalescence in rock. The phase field model is implemented in COMSOL and is based on the strain decomposition for the elastic energy, which drives the evolution of the phase field. Then, numerical simulations of notched semi-circular bend (NSCB) tests and Brazil splitting tests are performed. Subsequently, crack propagation and coalescence in rock plates with multiple echelon flaws and twenty parallel flaws are studied. Finally, complex crack patterns are presented for a plate subjected to increasing internal pressure, the (3D) Pertersson beam and a 3D NSCB test. All results are in good agreement with previous experimental and numerical results.