Thermo-elastic/Mechanical Topology Optimization/Simuation

(Optional) temperature limits, optimization of voxel mesh.

This is the implementation of the paper Thermo-elastic topology optimization with stress and temperature constraints. By the way, this procedure realized the thermo-elastic TO(topology optimization)(Thermo-elastic topology optimization with stress and temperature constraints., mechanical TO(top3d.pdf) and corresponding simulations.

Files

• 3rd/: third-party library
• assets/: user-defined assets
• examples/: several teaching examples
  • defined_model_writer: User defined voxel mesh/model as TO/simulation input.
  • clamped_model_writer: Clamped to 0 or 1 of the optimized density.
  • sim_mechanical: Mechanical simulation.
  • sim_thermoelastic: Thermo-elastic simulation.
  • top_mechanical: Mechanical TO.
  • top_thermoelastic: Thermoelastic TO.
• output/: output directory
• ref/: reference material
• src/: source code
• cmake/: CMake files

Dependencies

Inside libraries:

• mma: constrained optimization algorithm
• Eigen: linear algebra
• libigl: basic geometry functions
• AMGCL: Linear solver. Optional.
• json: parsing input JSON scenes
• spdlog: logging information
• OpenMP: CPU parallel processing.

  sudo apt install libomp-dev
  

The following dependencies require user installation:

• SuiteSparse: Linear solver. Optional, NOTE: Use of the Intel MKL BLAS is strongly recommended.
• CUDA Toolkit: CUDA support. Optional (Strongly recommend).

Select a Linear solver

If your matrix has less than 50w of freedom, then it is recommended to choose a direct solver (e.g. SuiteSparse):

1. install SuiteSparse.
2. Set ENABLE_AMGCL to OFF and set ENABLE_SUITESPARSE to ON in CMakeLists.txt.

Otherwise, it is recommended to choose an iterative solver (e.g. AMGCL),in CPU:

1. install OpenMP and AMGCL.
2. Set ENABLE_AMGCL to ON, ENABLE_AMGCL_CUDA to OFF and ENABLE_SUITESPARSE to OFF in CMakeLists.txt.

Further, CUDA can be used to speed up the iterative solver:

1. install OpenMP, CUDA Toolkit and AMGCL.
2. Set ENABLE_AMGCL to ON, ENABLE_AMGCL_CUDA to ON and ENABLE_SUITESPARSE to OFF in CMakeLists.txt.

Finally, if all options are set to OFF, then the Eigen build-in iterative solver will be chosen.(not recommended).

Build

1. set path in CMakeLists.txt.

set(CMAKE_CUDA_COMPILER "/path/to/nvcc") # set path to nvcc(if AMGCL_CUDA is ON)

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make -j 16

Usage

updated: top and sim sequence

1. Use example/defined_model_writer to generate a user-defined voxel mesh/model as TO input.
2. Use example/top_mechanical to run mechanical TO.
3. Use example/top_thermoelastic to run thermo-elastic TO.(||Fth|| / ||Fm|| means the ratio of the thermal force to the mechanical force, the value suggested is 0.1-10).
4. Use example/clamped_model_writer to clamp the optimized density to 0 or 1(select a suitable threshold) as SIM input.
5. Use example/sim_mechanical to run mechanical simulation.
6. Use example/sim_thermoelastic to run thermo-elastic simulation.

Note:

1. open *.vtk via Paraview.
2. Input
   1. Set parameters in *.json. see comments in assets/top-thermoelastic-*.json(see comments in assets/config_biclamed.json and ref paper for MeTh parameters; see comments in assets/top/config_Lshape.json)
   2. Redirect in main.cpp or main.cu if ENABLE_AMGCL_CUDA is ON:
   3. "//*" in config_*.json file mean comments.
3. Output see output/txt/${example_name}, output/txt/${example_name}/${clamed_example_name*}/ and output/vtk/${example_name}/${clamed_example_name*}/.
4. you can modify OUTPUT_DIR and ASSETS_DIR in CMAKEList.txt.
5. you can modify the linear solver arguments prm.solver.tol and prm.solver.maxiter in src/LinearSolver/Amgcl.h or src/LinearSolver/AmgclCuda.h.
6. you should modify example content in *.cpp rather than *.cu, the latter is copied from the former by cmake.

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