DataAnalyticsEngineering · sanathkeshav · Aug 2, 2026 · Mar 17, 2026 · Mar 21, 2026 · Mar 30, 2026
diff --git a/.github/workflows/build_and_test.yaml b/.github/workflows/build_and_test.yaml
@@ -30,10 +30,10 @@ jobs:
         UBUNTU_VERSION: [noble, jammy]
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Set up pixi
-        uses: prefix-dev/setup-pixi@v0.9.4
+        uses: prefix-dev/setup-pixi@v0.10.0
         with:
           environments: dashboard
 

diff --git a/.github/workflows/docker.yaml b/.github/workflows/docker.yaml
@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v4

diff --git a/.github/workflows/pixi_build.yaml b/.github/workflows/pixi_build.yaml
@@ -20,10 +20,10 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Set up pixi
-        uses: prefix-dev/setup-pixi@v0.9.4
+        uses: prefix-dev/setup-pixi@v0.10.0
         with:
           environments: default
 

diff --git a/.github/workflows/run-checks.yml b/.github/workflows/run-checks.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
       - name: Create markdownlint config
         run: |
           cat > .markdownlint.json << 'EOF'
@@ -35,7 +35,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
       - name: Create markdown-link-check config
         run: |
           cat > .markdown-link-check-config.json << 'EOF'
@@ -59,9 +59,9 @@ jobs:
     name: pre-commit checks
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - name: Setup python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@v7
         with:
           python-version: '3.10'
           check-latest: true

diff --git a/.github/workflows/test_pyfans.yaml b/.github/workflows/test_pyfans.yaml
@@ -22,7 +22,7 @@ jobs:
     steps:
 
     - name: Checkout repository
-      uses: actions/checkout@v6
+      uses: actions/checkout@v7
 
     - name: Generate build directory
       run: mkdir -p ${{ env.FANS_BUILD_DIR }}

diff --git a/.gitignore b/.gitignore
@@ -199,14 +199,17 @@ test/input_files/**/*.json
 
 # Test microstructure files
 !sphere32.h5
+!diamond_GB.h5
 
 # Test input files
 !test_LinearElastic.json
 !test_LinearThermal.json
+!test_GBDiffusion.json
 !test_PseudoPlastic.json
 !test_J2Plasticity.json
 !test_MixedBCs.json
 !test_CompressibleNeoHookean.json
+!test_FiniteStrainJ2Plasticity.json
 !test_MixedBCs_LargeStrain.json
 
 # pixi environments

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # FANS Changelog
 
+## v0.7.0
+
+- Add configurable logging using `spdlog` [#150](https://github.com/DataAnalyticsEngineering/FANS/pull/150)
+- Add rate-independent finite-strain J2 plasticity with linear isotropic hardening [#149](https://github.com/DataAnalyticsEngineering/FANS/pull/149)
+- Added large strain support for pyFANS [#141](https://github.com/DataAnalyticsEngineering/FANS/pull/141)
+- Bugfix: fixes GBDiffusion post MaterialManager update and adds a test case [#147](https://github.com/DataAnalyticsEngineering/FANS/pull/147)
+- Bugfix: mem-leak while reading microstructure and added wider CMake support [#140](https://github.com/DataAnalyticsEngineering/FANS/pull/140)
+- Added MPI communicator abstraction [#139](https://github.com/DataAnalyticsEngineering/FANS/pull/139)
+
 ## v0.6.2
 
 - Fix bug demanding a leading slash in the datasetname and exiting ungracefully [#123](https://github.com/DataAnalyticsEngineering/FANS/pull/123)

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -5,7 +5,7 @@ cmake_minimum_required(VERSION 3.21)
 # ##############################################################################
 
 project(FANS
-        VERSION 0.6.2
+        VERSION 0.7.0
         LANGUAGES C CXX
 )
 
@@ -108,6 +108,7 @@ if (FANS_LIBRARY_FOR_MICRO_MANAGER)
     FetchContent_MakeAvailable(pybind11)
 endif()
 find_package(nlohmann_json REQUIRED)
+find_package(spdlog CONFIG REQUIRED)
 # ##############################################################################
 # TARGETS
 # ##############################################################################
@@ -150,7 +151,9 @@ target_include_directories(FANS_FANS PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SO
 # FANS.h header that consuming projects can use
 set_property(TARGET FANS_FANS PROPERTY PUBLIC_HEADER
         include/general.h
+        include/logging.h
         include/matmodel.h
+        include/LargeStrainMechModel.h
         include/MaterialManager.h
         include/reader.h
         include/solverCG.h
@@ -159,16 +162,17 @@ set_property(TARGET FANS_FANS PROPERTY PUBLIC_HEADER
         include/setup.h
         include/mixedBCs.h
 
-        include/material_models/LinearThermal.h
-        include/material_models/GBDiffusion.h
+        include/material_models/thermal/LinearThermal.h
+        include/material_models/thermal/GBDiffusion.h
 
-        include/material_models/LinearElastic.h
-        include/material_models/PseudoPlastic.h
-        include/material_models/J2Plasticity.h
-        include/material_models/J2PlasticityNew.h
+        include/material_models/small_strain/LinearElastic.h
+        include/material_models/small_strain/PseudoPlastic.h
+        include/material_models/small_strain/J2Plasticity.h
+        include/material_models/small_strain/J2PlasticityNew.h
 
-        include/material_models/SaintVenantKirchhoff.h
-        include/material_models/CompressibleNeoHookean.h
+        include/material_models/large_strain/SaintVenantKirchhoff.h
+        include/material_models/large_strain/CompressibleNeoHookean.h
+        include/material_models/large_strain/FiniteStrainJ2Plasticity.h
 )
 
 # version.h is generated and added to the build include directory
@@ -215,8 +219,9 @@ target_compile_definitions(FANS_FANS PUBLIC ${FFTW3_DEFINITIONS})
 
 target_link_libraries(FANS_FANS PUBLIC Eigen3::Eigen)
 target_link_libraries(FANS_FANS PUBLIC nlohmann_json::nlohmann_json)
+target_link_libraries(FANS_FANS PUBLIC spdlog::spdlog)
 
-target_include_directories(FANS_main PRIVATE ${HDF5_INCLUDE_DIRS})
+target_include_directories(FANS_main PRIVATE ${HDF5_INCLUDE_DIRS} ${FFTW3_INCLUDE_DIRS})
 target_link_libraries(FANS_main PRIVATE FANS::FANS)
 
 # ##############################################################################

diff --git a/FANS_Dashboard/FANS_Dashboard.ipynb b/FANS_Dashboard/FANS_Dashboard.ipynb
@@ -219,8 +219,7 @@
     "fig = plot_subplots(strain_average, stress_average, labels_x=['Strain']*6, labels_y=['Stress']*6, \n",
     "                    subplot_titles=['component - 11', 'component - 22', 'component - 33', 'component - 12', 'component - 13', 'component - 23'], \n",
     "                    title='Stress average vs strain average', \n",
-    "                    nrows=2, ncols=3, linewidth=1, markersize=4, linecolor=[\"blue\"]*6, markercolor=[\"blue\"]*6, fontsize=16)\n",
-    "fig.show()"
+    "                    nrows=2, ncols=3, linewidth=1, markersize=4, linecolor=[\"blue\"]*6, markercolor=[\"blue\"]*6, fontsize=16)"
    ]
   },
   {
@@ -233,8 +232,7 @@
     "fig = plot_subplots(strain_average, stress_average_deviatoric, labels_x=['Strain']*6, labels_y=['Stress_dev']*6,\n",
     "                    subplot_titles=['component - 11', 'component - 22', 'component - 33', 'component - 12', 'component - 13', 'component - 23'],\n",
     "                    title='Deviatoric stress average vs strain average',\n",
-    "                    nrows=2, ncols=3, linewidth=1, markersize=4, linecolor=[\"blue\"]*6, markercolor=[\"blue\"]*6, fontsize=16)\n",
-    "fig.show()"
+    "                    nrows=2, ncols=3, linewidth=1, markersize=4, linecolor=[\"blue\"]*6, markercolor=[\"blue\"]*6, fontsize=16)"
    ]
   },
   {
@@ -248,8 +246,7 @@
     "fig = plot_subplots(time_broadcasted, stress_average_deviatoric, labels_x=['Time']*6, labels_y=['Stress_dev']*6,\n",
     "                    subplot_titles=['component - 11', 'component - 22', 'component - 33', 'component - 12', 'component - 13', 'component - 23'],\n",
     "                    title='Deviatoric stress average vs time',\n",
-    "                    nrows=2, ncols=3, linewidth=1, markersize=4, linecolor=[\"blue\"]*6, markercolor=[\"blue\"]*6, fontsize=16)\n",
-    "fig.show()"
+    "                    nrows=2, ncols=3, linewidth=1, markersize=4, linecolor=[\"blue\"]*6, markercolor=[\"blue\"]*6, fontsize=16)"
    ]
   },
   {
@@ -262,8 +259,7 @@
     "                    np.column_stack((stress_average[:, 0], stress_average_deviatoric[:, 0])), \n",
     "                    labels_x=['Strain_11']*2, labels_y=['Stress_11', 'Stress_dev_11'],\n",
     "                    subplot_titles=['Stress_11 vs Strain_11', 'Stress_dev_11 vs Strain_11'],\n",
-    "                    nrows=1, ncols=2, linewidth=1, markersize=4, linecolor=[\"blue\"]*2, markercolor=[\"blue\"]*2, fontsize=16)\n",
-    "fig.show()"
+    "                    nrows=1, ncols=2, linewidth=1, markersize=4, linecolor=[\"blue\"]*2, markercolor=[\"blue\"]*2, fontsize=16)"
    ]
   },
   {

diff --git a/README.md b/README.md
@@ -7,6 +7,7 @@
   <a href="https://anaconda.org/conda-forge/fans"><img src="https://anaconda.org/conda-forge/fans/badges/platforms.svg" alt="Anaconda-Server Badge"></a>
   <a href="https://github.com/DataAnalyticsEngineering/FANS/actions"><img src="https://github.com/DataAnalyticsEngineering/FANS/workflows/Build%20and%20test%20pixi-build/badge.svg" alt="Build and test pixi-build"></a>
   <a href="https://anaconda.org/conda-forge/fans"><img src="https://anaconda.org/conda-forge/fans/badges/downloads.svg" alt="Anaconda-Server Badge"></a>
+  <a href="https://deepwiki.com/DataAnalyticsEngineering/FANS"><img src="https://deepwiki.com/badge.svg" alt="Ask DeepWiki"></a>
   <a href="https://prefix.dev/channels/conda-forge/packages/fans"><img src="https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/prefix-dev/pixi/main/assets/badge/v0.json" alt="Pixi Badge"></a>
   <img src="https://img.shields.io/github/last-commit/DataAnalyticsEngineering/FANS" alt="Last commit">
   <a href="https://github.com/DataAnalyticsEngineering/FANS/blob/main/LICENSE"><img src="https://img.shields.io/github/license/DataAnalyticsEngineering/FANS" alt="License"></a>
@@ -24,6 +25,7 @@ Fourier-Accelerated Nodal Solver (FANS) is an FFT-based homogenization solver fo
   - [Installing dependencies](#installing-dependencies)
   - [Building FANS](#building-fans)
 - [Python environment for the FANS dashboard](#python-environment-for-the-fans-dashboard)
+- [Publications using FANS](docs/PUBLICATIONS.md)
 - [Input file format](#input-file-format)
   - [Microstructure definition](#microstructure-definition)
   - [Problem type and material model](#problem-type-and-material-model)
@@ -71,6 +73,7 @@ FANS requires the following dependencies:
 | **FFTW3** | FFT computations | **with MPI support** |
 | **Eigen3** | Linear algebra | ≥ 3.4 |
 | **nlohmann-json** | JSON parsing | ≥ 3.11 |
+| **spdlog** | Logging | ≥ 1.17 |
 
 ### Installing dependencies
 
@@ -108,7 +111,8 @@ apt-get install -y \
     libeigen3-dev \
     libfftw3-dev \
     libfftw3-mpi-dev \
-    nlohmann-json3-dev
+    nlohmann-json3-dev \
+    libspdlog-dev
 ```
 
 </details>
@@ -122,7 +126,7 @@ We recommend installing the dependencies using [`brew`](https://brew.sh):
 brew install gnu-time cmake gcc@15
 brew install open-mpi --build-from-source --cc=gcc-15
 brew install hdf5-mpi --build-from-source --cc=gcc-15
-brew install fftw eigen nlohmann-json
+brew install fftw eigen nlohmann-json spdlog
 
 # Set environment variables
 export CC=gcc-15 CXX=g++-15 MPICC=mpicc MPICXX=mpicxx
@@ -142,9 +146,10 @@ spack install hdf5+cxx+mpi
 spack install eigen
 spack install fftw+mpi
 spack install nlohmann-json
+spack install spdlog
 
 # Load dependencies
-spack load cmake mpi hdf5 eigen fftw nlohmann-json
+spack load cmake mpi hdf5 eigen fftw nlohmann-json spdlog
 ```
 
 Additionally, optimized FFTW implementations can be used depending on your system's architecture:
@@ -278,6 +283,7 @@ FANS requires a JSON input file specifying the problem parameters. Example input
     - `J2ViscoPlastic_LinearIsotropicHardening` / `J2ViscoPlastic_NonLinearIsotropicHardening` for rate-independent / dependent J2 plasticity model with kinematic and linear/nonlinear isotropic hardening.
     - `SaintVenantKirchhoff` for the hyperelastic Saint Venant-Kirchhoff material model.
     - `CompressibleNeoHookean` for the compressible Neo-Hookean material model.
+    - `FiniteStrainJ2Plasticity` for rate-independent finite-strain J2 plasticity with linear isotropic hardening.
 
   - `material_properties`: Material parameters specific to the chosen model. Properties are defined as arrays, where each element corresponds to one of the phases listed in the `phases` array.
 

diff --git a/cmake/FANSConfig.cmake.in b/cmake/FANSConfig.cmake.in
@@ -20,6 +20,7 @@ endif()
 find_dependency(Eigen3)
 find_dependency(MPI)
 find_dependency(FFTW3 COMPONENTS DOUBLE MPI)
+find_dependency(spdlog CONFIG)
 
 set(CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH_save}")
 unset(CMAKE_MODULE_PATH_save)

diff --git a/cmake/modules/FindFFTW3.cmake b/cmake/modules/FindFFTW3.cmake
@@ -72,11 +72,15 @@ macro(find_specific_libraries KIND PARALLEL)
     # adding target properties to the different cases
     ##   MPI
     if(PARALLEL STREQUAL "MPI")
-      if(MPI_C_LIBRARIES)
-        set_target_properties(fftw3::${kind}::mpi PROPERTIES
-          IMPORTED_LOCATION "${FFTW3_${KIND}_${PARALLEL}_LIBRARY}"
-          INTERFACE_INCLUDE_DIRECTORIES "${FFTW3_INCLUDE_DIR_PARALLEL}"
-          IMPORTED_LINK_INTERFACE_LIBRARIES ${MPI_C_LIBRARIES})
+      set_target_properties(fftw3::${kind}::mpi PROPERTIES
+        IMPORTED_LOCATION "${FFTW3_${KIND}_${PARALLEL}_LIBRARY}"
+        INTERFACE_INCLUDE_DIRECTORIES "${FFTW3_INCLUDE_DIR_PARALLEL}"
+      )
+
+      if(MPI_C_LIBRARIES AND NOT MPI_C_LIBRARIES STREQUAL "")
+        set_property(TARGET fftw3::${kind}::mpi PROPERTY
+          INTERFACE_LINK_LIBRARIES "${MPI_C_LIBRARIES}"
+        )
       endif()
     endif()
     ##   OpenMP

diff --git a/docker/Dockerfile b/docker/Dockerfile
@@ -42,6 +42,7 @@ RUN apt-get update -qq && apt-get install -y --no-install-recommends \
     libfftw3-dev \
     libfftw3-mpi-dev \
     nlohmann-json3-dev \
+    libspdlog-dev \
 # Required for preCICE Micro Manager Python bindings
     python3-dev \
 # Clean up

diff --git a/docs/PUBLICATIONS.md b/docs/PUBLICATIONS.md
@@ -0,0 +1,27 @@
+# Publications using FANS
+
+The following studies used FANS extensively as a primary data-generation tool.
+
+## 2026
+
+- Sanath Keshav and Felix Fritzen. **Robust Inverse Material Design With Physical Guarantees Using the Voigt–Reuss Net.** *International Journal for Numerical Methods in Engineering*, 127(7), 2026. ([10.1002/nme.70296](https://doi.org/10.1002/nme.70296))
+- Yongliang Ou, Lena Scholz, Sanath Keshav, Yuji Ikeda, Marvin Kraft, Sergiy V. Divinski, Rafael Gómez-Bombarelli, Wolfgang Zeier, Felix Fritzen, and Blazej Grabowski. **Non-Arrhenius Li-ion transport and grain-size effects in argyrodite solid electrolytes.** Preprint, 2026. ([10.21203/rs.3.rs-7913719/v1](https://doi.org/10.21203/rs.3.rs-7913719/v1))
+
+## 2025
+
+- Alexandra Otto, Max Rosenkranz, Karl A. Kalina, and Markus Kästner. **Data-Driven Inverse Design of Spinodoid Architected Materials.** *GAMM-Mitteilungen*, 48(4), 2025. ([10.1002/gamm.70008](https://doi.org/10.1002/gamm.70008))
+- Max Rosenkranz, Markus Kästner, and Ivo F. Sbalzarini. **Data-Efficient Inverse Design of Spinodoid Metamaterials.** *Integrating Materials and Manufacturing Innovation*, 14(4), 695–713, 2025. ([10.1007/s40192-025-00426-1](https://doi.org/10.1007/s40192-025-00426-1))
+- Sanath Keshav, Julius Herb, and Felix Fritzen. **Spectral Normalization and Voigt–Reuss Net: A universal approach to microstructure-property forecasting with physical guarantees.** *GAMM-Mitteilungen*, 48(3), 2025. ([10.1002/gamm.70005](https://doi.org/10.1002/gamm.70005))
+- Felix Fritzen, Julius Herb, and Shadi Sharba. **Thermo-plastic Nonuniform Transformation Field Analysis for eigenstress analysis of materials undergoing laser melt injection.** *Computer Methods in Applied Mechanics and Engineering*, 433, 117487, 2025. ([10.1016/j.cma.2024.117487](https://doi.org/10.1016/j.cma.2024.117487))
+
+## 2024
+
+- Julian Lißner and Felix Fritzen. **Microstructure homogenization: human vs machine.** *Advanced Modeling and Simulation in Engineering Sciences*, 11(1), 2024. ([10.1186/s40323-024-00275-1](https://doi.org/10.1186/s40323-024-00275-1))
+
+## 2023
+
+- Shadi Sharba, Julius Herb, and Felix Fritzen. **Reduced order homogenization of thermoelastic materials with strong temperature dependence and comparison to a machine-learned model.** *Archive of Applied Mechanics*, 93(7), 2855–2876, 2023. ([10.1007/s00419-023-02411-6](https://doi.org/10.1007/s00419-023-02411-6))
+
+## 2022
+
+- Sanath Keshav, Felix Fritzen, and Matthias Kabel. **FFT-based homogenization at finite strains using composite boxels (ComBo).** *Computational Mechanics*, 71(1), 191–212, 2022. ([10.1007/s00466-022-02232-4](https://doi.org/10.1007/s00466-022-02232-4))