# jax-fem **Repository Path**: deepmodeling/jax-fem ## Basic Information - **Project Name**: jax-fem - **Description**: No description available - **Primary Language**: Unknown - **License**: GPL-3.0 - **Default Branch**: main - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2024-04-11 - **Last Updated**: 2024-04-12 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README A GPU-accelerated differentiable finite element analysis package based on [JAX](https://github.com/google/jax). Used to be part of the suite of open-source python packages for Additive Manufacturing (AM) research, [JAX-AM](https://github.com/tianjuxue/jax-am). ## Finite Element Method (FEM) ![Github Star](https://img.shields.io/github/stars/deepmodeling/jax-fem) ![Github Fork](https://img.shields.io/github/forks/deepmodeling/jax-fem) ![License](https://img.shields.io/github/license/deepmodeling/jax-fem) FEM is a powerful tool, where we support the following features - 2D quadrilateral/triangle elements - 3D hexahedron/tetrahedron elements - First and second order elements - Dirichlet/Neumann/Robin boundary conditions - Linear and nonlinear analysis including - Heat equation - Linear elasticity - Hyperelasticity - Plasticity (macro and crystal plasticity) - Differentiable simulation for solving inverse/design problems __without__ human deriving sensitivities, e.g., - Topology optimization - Optimal thermal control - Integration with PETSc for solver choices **Updates** (Dec 11, 2023): - We now support multi-physics problems in the sense that multiple variables can be solved monolithically. For example, consider running `python -m applications.stokes.example` - Weak form is now defined through volume integral and surface integral. We can now treat body force, "mass kernel" and "Laplace kernel" in a unified way through volume integral, and treat "Neumann B.C." and "Robin B.C." in a unified way through surface integral.

Thermal profile in direct energy deposition.

Linear static analysis of a bracket.

Crystal plasticity: grain structure (left) and stress-xx (right).

Stokes flow: velocity (left) and pressure(right).

Topology optimization with differentiable simulation.

## Installation Create a conda environment from the given [`environment.yml`](https://github.com/deepmodeling/jax-fem/blob/main/environment.yml) file and activate it: ```bash conda env create -f environment.yml conda activate jax-fem-env ``` Install JAX - See jax installation [instructions](https://jax.readthedocs.io/en/latest/installation.html#). Depending on your hardware, you may install the CPU or GPU version of JAX. Both will work, while GPU version usually gives better performance. Then there are two options to continue: ### Option 1 Clone the repository: ```bash git clone https://github.com/deepmodeling/jax-fem.git cd jax-fem ``` and install the package locally: ```bash pip install -e . ``` **Quick tests**: You can check `demos/` for a variety of FEM cases. For example, run ```bash python -m demos.hyperelasticity.example ``` for hyperelasticity. Also, ```bash python -m tests.benchmarks ``` will execute a set of test cases. ### Option 2 Install the package from the [PyPI release](https://pypi.org/project/jax-fem/) directly: ```bash pip install jax-fem ``` **Quick tests**: You can create an `example.py` file and run it: ```bash python example.py ``` ```python import jax import jax.numpy as np import os from jax_fem.problem import Problem from jax_fem.solver import solver from jax_fem.utils import save_sol from jax_fem.generate_mesh import get_meshio_cell_type, Mesh, rectangle_mesh class Poisson(Problem): def get_tensor_map(self): return lambda x: x def get_mass_map(self): def mass_map(u, x): val = -np.array([10*np.exp(-(np.power(x[0] - 0.5, 2) + np.power(x[1] - 0.5, 2)) / 0.02)]) return val return mass_map def get_surface_maps(self): def surface_map(u, x): return -np.array([np.sin(5.*x[0])]) return [surface_map, surface_map] ele_type = 'QUAD4' cell_type = get_meshio_cell_type(ele_type) Lx, Ly = 1., 1. meshio_mesh = rectangle_mesh(Nx=32, Ny=32, domain_x=Lx, domain_y=Ly) mesh = Mesh(meshio_mesh.points, meshio_mesh.cells_dict[cell_type]) def left(point): return np.isclose(point[0], 0., atol=1e-5) def right(point): return np.isclose(point[0], Lx, atol=1e-5) def bottom(point): return np.isclose(point[1], 0., atol=1e-5) def top(point): return np.isclose(point[1], Ly, atol=1e-5) def dirichlet_val_left(point): return 0. def dirichlet_val_right(point): return 0. location_fns = [left, right] value_fns = [dirichlet_val_left, dirichlet_val_right] vecs = [0, 0] dirichlet_bc_info = [location_fns, vecs, value_fns] location_fns = [bottom, top] problem = Poisson(mesh=mesh, vec=1, dim=2, ele_type=ele_type, dirichlet_bc_info=dirichlet_bc_info, location_fns=location_fns) sol = solver(problem, linear=True, use_petsc=True) data_dir = os.path.join(os.path.dirname(__file__), 'data') vtk_path = os.path.join(data_dir, f'vtk/u.vtu') save_sol(problem.fes[0], sol[0], vtk_path) ``` ## License This project is licensed under the GNU General Public License v3 - see the [LICENSE](https://www.gnu.org/licenses/) for details. ## Citations If you found this library useful in academic or industry work, we appreciate your support if you consider 1) starring the project on Github, and 2) citing relevant papers: ```bibtex @article{xue2023jax, title={JAX-FEM: A differentiable GPU-accelerated 3D finite element solver for automatic inverse design and mechanistic data science}, author={Xue, Tianju and Liao, Shuheng and Gan, Zhengtao and Park, Chanwook and Xie, Xiaoyu and Liu, Wing Kam and Cao, Jian}, journal={Computer Physics Communications}, pages={108802}, year={2023}, publisher={Elsevier} } ```