Overview

Description

gcrack is a 2D finite element solver for simulating crack propagation using Linear Elastic Fracture Mechanics. It is built on top of fenicsx.

It has several non-classic features :

crack propagation in anistropic media,
indirect load control using path-following methods.

Installation

To run gcrack, install the required Python modules in a dedicated environment:

Create and activate a new conda environment:

conda create -n gcrack
conda activate gcrack

Install the required dependencies:

conda install -c conda-forge numpy sympy mpich python-gmsh fenics-dolfinx pyvista jax jaxlib=*=*cpu*

Install gcrack:

pip install .       # If you cloned the repo
pip install gcrack  # If you want to install from pypi

Hands-On: Test with Examples

The examples directory contains ready-to-run scripts. Just follow these steps:

Navigate to the examples directory.
```
cd gcrack/examples/example_name
```
Activate the conda environment:
```
conda activate gcrack
```
Run the provided run.py script using the provided makefile:
```
make simulation
```
Vizualize the results in the directory results_YYY-MM-DD-HH-mm-ss/.

Usage

Requirements

To run a simulation, the only required file is a Python script (named run.py in the examples). It contains the definition of a class inheriting from GCrackBase. In this class, the methods to define the mesh (generate_mesh), to define the boundary conditions (e.g., define_controlled_displacements), and define the critical energy release rate (Gc) must be defined.

Running the Solver

Once the Python script is define, one only need to call the method GCrackBase.run to start the resolution.

Activate the gcrack environment:
```
conda activate gcrack
```
Run the solver:
```
python run.py
```

Notes

On some Linux distributions, set OMP_NUM_THREADS=1 to prevent FEniCSx from using all available threads:
```
OMP_NUM_THREADS=1 python run.py
```

Outputs

Results are saved in the results subdirectory. Two types of file are exported:

The displacement fields are saved in VTK files (with the extension .pvd).
The scalar outputs (displacement/force measures, stress intensity factors, etc.) are saved in the results.csv CSV file.

Vizualization

To open the VTK files, vizualization tools such as Paraview or pyvsita can be employed.