UMAT_2scale_LSDYNA

Basics to implement user-defined material routines in LS-Dyna with Python and C++. This repo realizes two scale simulation schemes in LS-DYNA.

External dependencies

Dependencies below are included in the external_packages directory. They may be included as submodules but for the sake of reproducablity a frozen version of their corresponding repositories is included here.

• ttb: Tensor Toolbox for Modern Fortran (ttb), hosted at https://github.com/adtzlr/ttb

• forpy: A library for Fortran-Python interoperability, hosted at https://github.com/ylikx/forpy

• ezh5: Easy HDF5 C++ Library, hosted at https://github.com/mileschen360/ezh5

  Test cases of these packages are included in external_packages/test_*.sh

Licensing

See the license file for the project license and the licenses of the included dependencies.

Citations

Shadi Sharba, Felix Fritzen, Julius Herb. LS-DYNA two-scale homogenization extension. Version 1.0.0 (2021).

@software{sharba2021,
  author       = {Shadi Sharba, Felix Fritzen, Julius Herb},
  title        = {LS-DYNA two-scale homogenization extension},
  month        = Aug,
  year         = 2021,
  version      = {v1.0.0},
  url          = {https://github.com/DataAnalyticsEngineering/UMAT_2scale_LSDYNA}
}

Compiling using docker

• Install docker on your machine. You can use the following command (for further details, please check this link)

curl -fsSL https://get.docker.com -o get-docker.sh
sh get-docker.sh

• Obtain the new interface files from GitHub:

git clone https://github.com/DataAnalyticsEngineering/UMAT_2scale_LSDYNA.git && cd UMAT_2scale_LSDYNA

• Obtain ls-dyna_smp_d_R12_0_0_x64_redhat65_ifort160.tgz usermat package/object version of LS-DYNA from your local distributor of LS-DYNA and place it in UMAT_2scale_LSDYNA. Here are some helpful links (lsdyna-ansys,ansys-forum).

• Using a terminal, run 0_run_in_docker.sh to build the docker image and enter the running container. Or use VSCode with the Dev Containers extension; Open the UMAT_2scale_LSDYNA foldr then use reopen in container command to build and open the project in the container.

• Inside the container, run 1_setup_dyna.sh to compile the new object version of LS-DYNA. The new executable will be placed inside the docker container in UMAT_2scale_LSDYNA/lsdyna_object_version/lsdynaumat

Test cases:

You can use 2_run_tests.sh inside the docker container to run the following test cases:

• External packages: test cases of these packages are included in external_packages/test_*.sh
  • test_ttb.sh
  • test_forpy.sh
  • test_ezh5.sh
• Mixed language programming
  • test_call_cpp.sh: compiles and runs a Fortran function that calls a C++ one
  • test_call_py.sh: compiles and runs a Fortran function that calls a Python one via C++

Examples:

Check 3_run_examples.sh to know how to run the following examples:

• examples/two_scale/analytical_mat_parameter

  Temperature dependent material parameters are considered here and given as lambda functions in material_parameters.py.

  To get an idea about the implementation check:

  • umat_elastic_44_14.F90
  • material_parameters.py
  • umat.py

• examples/two_scale/homogeneous_single_track

  Here, an RVE effective response under different load temperatures is assumed to exist and stored in a tabulated format in an HDF5 file. Linear interpolation is used to evaluate effective properties at current temperature given the stored response at one higher and one lower temperatures.

  To get an idea about the implementation check:

  • umat_elastic_44_14.F90
  • umat.py
  • rve_elastic.py

• Discontinued

  • examples/two_scale/3d_rve
  • examples/two_scale/2d_rve

  Here, a thermo-mechanical response of a representative volume element is computed using LS-DYNA.