diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bab3d93620..85eb5f9e5b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,12 +1,12 @@
 name: CI
 
-# Controls when the action will run. 
+# Controls when the action will run.
 on:
   # Triggers the workflow on push or pull request events but only for the master branch
   push:
-    branches: [ master ]
+    branches: [master]
   pull_request:
-    branches: [ master ]
+    branches: [master]
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
 
@@ -16,7 +16,6 @@ env:
 
 # A workflow is made up of one or more jobs that can run sequentially or in parallel
 jobs:
-
   ###############################################################################
   Linux-float:
     runs-on: ubuntu-22.04
@@ -47,7 +46,7 @@ jobs:
           key: ${{ github.job }}
 
       - uses: friendlyanon/setup-vcpkg@v1 # Setup vcpkg into ${{github.workspace}}
-        with: 
+        with:
           committish: ${{ env.VCPKG_VERSION }}
           cache: false
 
@@ -78,11 +77,11 @@ jobs:
             -D SPHINXSYS_CI=ON \
             -S ${{github.workspace}} \
             -B ${{github.workspace}}/build
-            
+
       - name: Build using float
         run: cmake --build build --config Release --verbose
 
-  ###############################################################################   
+  ###############################################################################
   Linux-build:
     runs-on: ubuntu-22.04
     env:
@@ -112,7 +111,7 @@ jobs:
           key: ${{ github.job }}
 
       - uses: friendlyanon/setup-vcpkg@v1 # Setup vcpkg into ${{github.workspace}}
-        with: 
+        with:
           committish: ${{ env.VCPKG_VERSION }}
           cache-version: ${{env.VCPKG_VERSION}}
 
@@ -144,7 +143,7 @@ jobs:
             -D SPHINXSYS_MODULE_OPENCASCADE=ON \
             -S ${{github.workspace}} \
             -B ${{github.workspace}}/build
-            
+
       - name: Build using double
         run: cmake --build build --config Release --verbose
 
@@ -183,7 +182,7 @@ jobs:
             libgl-dev
 
       - uses: friendlyanon/setup-vcpkg@v1 # Setup vcpkg into ${{github.workspace}}
-        with: 
+        with:
           committish: ${{ env.VCPKG_VERSION }}
           cache-version: ${{env.VCPKG_VERSION}}
 
@@ -219,7 +218,7 @@ jobs:
 
       - name: Test with the second try for failed cases
         id: second-try
-        if: ${{ steps.first-try.outcome == 'failure' }} 
+        if: ${{ steps.first-try.outcome == 'failure' }}
         run: |
           cd build 
           ctest --rerun-failed --output-on-failure
@@ -227,7 +226,7 @@ jobs:
 
       - name: Test with the third try for failed cases
         id: third-try
-        if: ${{ steps.second-try.outcome == 'failure' }} 
+        if: ${{ steps.second-try.outcome == 'failure' }}
         run: |
           cd build 
           ctest --rerun-failed --output-on-failure
@@ -235,40 +234,41 @@ jobs:
 
       - name: Test with the fourth try for failed cases
         id: fourth-try
-        if: ${{ steps.third-try.outcome == 'failure' }} 
+        if: ${{ steps.third-try.outcome == 'failure' }}
         run: |
           cd build 
           ctest --rerun-failed --output-on-failure
         continue-on-error: true
 
       - name: Test with the last try for failed cases
-        if: ${{ steps.fourth-try.outcome == 'failure' }} 
+        if: ${{ steps.fourth-try.outcome == 'failure' }}
         run: |
           cd build 
           ctest --rerun-failed --output-on-failure
 
   ###############################################################################
 
-  Windows:
+  Windows-build:
     runs-on: windows-latest
     env:
       VCPKG_DEFAULT_TRIPLET: x64-windows
 
     steps:
       - uses: actions/checkout@v3 # Checks-out the repository under ${{github.workspace}}
-      
+
       - name: Update ccache and ninja # For correct caching with ccache on Windows
         shell: bash
         run: |
           choco install ccache
           choco install ninja
-          
+          choco install 7zip
+
       - uses: hendrikmuhs/ccache-action@v1.2
         with:
           key: ${{ github.job }}
 
       - uses: friendlyanon/setup-vcpkg@v1 # Setup vcpkg into ${{github.workspace}}
-        with: 
+        with:
           committish: ${{ env.VCPKG_VERSION }}
           cache-version: ${{env.VCPKG_VERSION}}
 
@@ -282,7 +282,7 @@ jobs:
             simbody `
             gtest `
             xsimd `
-            pybind11 
+            pybind11
 
       - uses: ilammy/msvc-dev-cmd@v1
 
@@ -296,10 +296,64 @@ jobs:
             -D TEST_STATE_RECORDING=OFF `
             -S ${{github.workspace}} `
             -B C:\build
-      
+
       - name: Build
         run: cmake.exe --build C:\build --config Release --verbose
 
+      - name: Zip build folder
+        run: 7z.exe a C:\build.7z "C:\build"
+
+      - uses: actions/upload-artifact@v3
+        with:
+          name: Windows-build
+          path: C:\build.7z
+          if-no-files-found: error
+          retention-days: 1
+
+  Windows-test:
+    needs: Windows-build
+    runs-on: windows-latest
+    env:
+      VCPKG_DEFAULT_TRIPLET: x64-windows
+
+    steps:
+      - uses: actions/checkout@v3 # Checks-out the repository under ${{github.workspace}}
+
+      - name: Update ccache and ninja # For correct caching with ccache on Windows
+        shell: bash
+        run: |
+          choco install ccache
+          choco install ninja
+          choco install 7zip
+
+      - uses: hendrikmuhs/ccache-action@v1.2
+        with:
+          key: ${{ github.job }}
+
+      - uses: friendlyanon/setup-vcpkg@v1 # Setup vcpkg into ${{github.workspace}}
+        with:
+          committish: ${{ env.VCPKG_VERSION }}
+          cache-version: ${{env.VCPKG_VERSION}}
+
+      - name: Install dependencies
+        run: |
+          ${{github.workspace}}\vcpkg\vcpkg.exe install --clean-after-build `
+            eigen3 `
+            tbb `
+            boost-program-options `
+            boost-geometry `
+            simbody `
+            gtest `
+            xsimd `
+            pybind11
+
+      - uses: actions/download-artifact@v3
+        with:
+          name: Windows-build
+
+      - name: Unzip build folder
+        run: 7z.exe x build.7z -oC:\
+
       - name: Test with the first try
         id: first-try
         run: |
@@ -309,7 +363,7 @@ jobs:
 
       - name: Test with the second try for failed cases
         id: second-try
-        if: ${{ steps.first-try.outcome == 'failure' }} 
+        if: ${{ steps.first-try.outcome == 'failure' }}
         run: |
           cd C:\build 
           ctest.exe --rerun-failed --output-on-failure
@@ -317,7 +371,7 @@ jobs:
 
       - name: Test with the third try for failed cases
         id: third-try
-        if: ${{ steps.second-try.outcome == 'failure' }} 
+        if: ${{ steps.second-try.outcome == 'failure' }}
         run: |
           cd C:\build 
           ctest.exe --rerun-failed --output-on-failure
@@ -325,21 +379,21 @@ jobs:
 
       - name: Test with the fourth try for failed cases
         id: fourth-try
-        if: ${{ steps.third-try.outcome == 'failure' }} 
+        if: ${{ steps.third-try.outcome == 'failure' }}
         run: |
           cd C:\build 
           ctest.exe --rerun-failed --output-on-failure
         continue-on-error: true
 
       - name: Test with the last try for failed cases
-        if: ${{ steps.fourth-try.outcome == 'failure' }} 
+        if: ${{ steps.fourth-try.outcome == 'failure' }}
         run: |
           cd C:\build 
           ctest.exe --rerun-failed --output-on-failure
 
   ###############################################################################
 
-  macOS:
+  macOS-build:
     runs-on: macos-12
     env:
       VCPKG_DEFAULT_TRIPLET: x64-osx
@@ -358,14 +412,16 @@ jobs:
             pkg-config `# for installing libraries with vcpkg`\
             git \
             cmake \
-            ninja
+            ninja \
+            zip \
+            unzip
 
       - uses: hendrikmuhs/ccache-action@v1.2
         with:
           key: ${{ github.job }}
 
       - uses: friendlyanon/setup-vcpkg@v1 # Setup vcpkg into ${{github.workspace}}
-        with: 
+        with:
           committish: ${{ env.VCPKG_VERSION }}
           cache-version: ${{env.VCPKG_VERSION}}
 
@@ -397,6 +453,67 @@ jobs:
       - name: Build
         run: cmake --build build --config Release --verbose
 
+      - name: Zip build folder
+        run: zip -r build.zip ./build
+
+      - uses: actions/upload-artifact@v3
+        with:
+          name: macOS-build
+          path: ${{github.workspace}}/build.zip
+          if-no-files-found: error
+          retention-days: 1
+
+  macOS-test:
+    needs: macOS-build
+    runs-on: macos-12
+    env:
+      VCPKG_DEFAULT_TRIPLET: x64-osx
+
+    steps:
+      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+      - uses: actions/checkout@v3
+
+      - name: Install system dependencies
+        run: |
+          brew reinstall gfortran # to force having gfortran on PATH because github runners don't have it, just the versioned aliases, i.e. gfortran-11
+                                  # https://github.com/actions/runner-images/blob/main/images/macos/macos-12-Readme.md
+                                  # https://github.com/actions/runner-images/issues/3371#issuecomment-839882565
+                                  # https://github.com/modflowpy/install-gfortran-action and https://github.com/awvwgk/setup-fortran
+          brew install \
+            pkg-config `# for installing libraries with vcpkg`\
+            git \
+            cmake \
+            ninja
+
+      - uses: hendrikmuhs/ccache-action@v1.2
+        with:
+          key: ${{ github.job }}
+
+      - uses: friendlyanon/setup-vcpkg@v1 # Setup vcpkg into ${{github.workspace}}
+        with:
+          committish: ${{ env.VCPKG_VERSION }}
+          cache-version: ${{env.VCPKG_VERSION}}
+
+      - name: Install dependencies
+        run: |
+          ${{github.workspace}}/vcpkg/vcpkg install --clean-after-build --allow-unsupported \
+            eigen3 \
+            tbb \
+            boost-program-options \
+            boost-geometry \
+            gtest \
+            simbody \
+            xsimd \
+            pybind11 \
+            opencascade
+
+      - uses: actions/download-artifact@v3
+        with:
+          name: macOS-build
+
+      - name: Unzip build folder
+        run: unzip build.zip
+
       - name: Test with the first try
         id: first-try
         run: |
@@ -406,7 +523,7 @@ jobs:
 
       - name: Test with the second try for failed cases
         id: second-try
-        if: ${{ steps.first-try.outcome == 'failure' }} 
+        if: ${{ steps.first-try.outcome == 'failure' }}
         run: |
           cd build 
           ctest --rerun-failed --output-on-failure
@@ -414,7 +531,7 @@ jobs:
 
       - name: Test with the third try for failed cases
         id: third-try
-        if: ${{ steps.second-try.outcome == 'failure' }} 
+        if: ${{ steps.second-try.outcome == 'failure' }}
         run: |
           cd build 
           ctest --rerun-failed --output-on-failure
@@ -422,14 +539,14 @@ jobs:
 
       - name: Test with the fourth try for failed cases
         id: fourth-try
-        if: ${{ steps.third-try.outcome == 'failure' }} 
+        if: ${{ steps.third-try.outcome == 'failure' }}
         run: |
           cd build 
           ctest --rerun-failed --output-on-failure
         continue-on-error: true
 
       - name: Test with the last try for failed cases
-        if: ${{ steps.fourth-try.outcome == 'failure' }} 
+        if: ${{ steps.fourth-try.outcome == 'failure' }}
         run: |
           cd build 
           ctest --rerun-failed --output-on-failure
diff --git a/PythonScriptStore/RegressionTest/regression_test_base_tool.py b/PythonScriptStore/RegressionTest/regression_test_base_tool.py
index 022ad83b98..206e175657 100644
--- a/PythonScriptStore/RegressionTest/regression_test_base_tool.py
+++ b/PythonScriptStore/RegressionTest/regression_test_base_tool.py
@@ -30,7 +30,7 @@ def compile_case(self) -> None:
 
     def run_particle_relaxation(self) -> None:
         print('Start particle relaxation for the simulation...')
-        command = f".{os.sep}{self.sphinxsys_case_name} --r=true"
+        command = f".{os.sep}{self.sphinxsys_case_name} --relax=true"
         os.system(self.enter_sphinxsys_exec_folder)
         os.system(command)
         print('Simulating case is finished...')
@@ -38,7 +38,7 @@ def run_particle_relaxation(self) -> None:
     def run_case(self) -> None:
         print('Start case simulation...')
         print(self.enter_sphinxsys_exec_folder)
-        command = f".{os.sep}{self.sphinxsys_case_name} --r=false --rt=true"
+        command = f".{os.sep}{self.sphinxsys_case_name} --regression=true"
         os.system(self.enter_sphinxsys_exec_folder)
         os.system(command)
         print('Simulating case is finished...')
@@ -46,7 +46,7 @@ def run_case(self) -> None:
     def run_case_with_reload(self) -> None:
         print('Start case simulation with particle reload...')
         print(self.enter_sphinxsys_exec_folder)
-        command = f".{os.sep}{self.sphinxsys_case_name} --r=false --i=true --rt=true"
+        command = f".{os.sep}{self.sphinxsys_case_name} --reload=true --regression=true"
         os.system(self.enter_sphinxsys_exec_folder)
         os.system(command)
         print('Simulating case is finished...')
@@ -96,7 +96,7 @@ def copy_reload(self) -> None:
 
     def run_particle_relaxation(self) -> None:
         print('Start particle relaxation for the simulation...')
-        command = f".{os.sep}{self.sphinxsys_case_name} --r=true"
+        command = f".{os.sep}{self.sphinxsys_case_name} --relax=true"
         os.chdir(self.sphinxsys_exec_path)
         os.system(command)
         print('Simulating case is finished...')
@@ -104,7 +104,7 @@ def run_particle_relaxation(self) -> None:
     def run_case(self) -> None:
         print('Start case simulation...')
         print(self.enter_sphinxsys_exec_folder)
-        command = f".{os.sep}{self.sphinxsys_case_name} --r=false --rt=true"
+        command = f".{os.sep}{self.sphinxsys_case_name} --regression=true"
         os.chdir(self.sphinxsys_exec_path)
         os.system(command)
         print('Simulating case is finished...')
@@ -112,7 +112,7 @@ def run_case(self) -> None:
     def run_case_with_reload(self) -> None:
         print('Start case simulation with particle reload...')
         print(self.enter_sphinxsys_exec_folder)
-        command = f".{os.sep}{self.sphinxsys_case_name} --r=false --i=true --rt=true"
+        command = f".{os.sep}{self.sphinxsys_case_name} --reload=true --regression=true"
         os.chdir(self.sphinxsys_exec_path)
         os.system(command)
         print('Simulating case is finished...')
diff --git a/src/shared/sphinxsys_system/sph_system.cpp b/src/shared/sphinxsys_system/sph_system.cpp
index c5f906f5d4..1e6cae51aa 100644
--- a/src/shared/sphinxsys_system/sph_system.cpp
+++ b/src/shared/sphinxsys_system/sph_system.cpp
@@ -54,9 +54,9 @@ void SPHSystem::handleCommandlineOptions(int ac, char *av[])
 
         po::options_description desc("Allowed options");
         desc.add_options()("help", "produce help message");
-        desc.add_options()("r", po::value<bool>(), "Particle relaxation.");
-        desc.add_options()("i", po::value<bool>(), "Particle reload from input file.");
-        desc.add_options()("rt", po::value<bool>(), "Regression test.");
+        desc.add_options()("relax", po::value<bool>(), "Particle relaxation.");
+        desc.add_options()("reload", po::value<bool>(), "Particle reload from input file.");
+        desc.add_options()("regression", po::value<bool>(), "Regression test.");
         desc.add_options()("state_recording", po::value<bool>(), "State recording in output folder.");
         desc.add_options()("restart_step", po::value<int>(), "Run form a restart file.");
 
@@ -70,11 +70,11 @@ void SPHSystem::handleCommandlineOptions(int ac, char *av[])
             exit(0);
         }
 
-        if (vm.count("r"))
+        if (vm.count("relax"))
         {
-            run_particle_relaxation_ = vm["r"].as<bool>();
+            run_particle_relaxation_ = vm["relax"].as<bool>();
             std::cout << "Particle relaxation was set to "
-                      << vm["r"].as<bool>() << ".\n";
+                      << vm["relax"].as<bool>() << ".\n";
         }
         else
         {
@@ -82,11 +82,11 @@ void SPHSystem::handleCommandlineOptions(int ac, char *av[])
                       << run_particle_relaxation_ << ").\n";
         }
 
-        if (vm.count("i"))
+        if (vm.count("reload"))
         {
-            reload_particles_ = vm["i"].as<bool>();
+            reload_particles_ = vm["reload"].as<bool>();
             std::cout << "Particle reload from input file was set to "
-                      << vm["i"].as<bool>() << ".\n";
+                      << vm["reload"].as<bool>() << ".\n";
         }
         else
         {
@@ -94,11 +94,11 @@ void SPHSystem::handleCommandlineOptions(int ac, char *av[])
                       << reload_particles_ << ").\n";
         }
 
-        if (vm.count("rt"))
+        if (vm.count("regression"))
         {
-            generate_regression_data_ = vm["rt"].as<bool>();
+            generate_regression_data_ = vm["regression"].as<bool>();
             std::cout << "Generate regression test data set was set to "
-                      << vm["rt"].as<bool>() << ".\n";
+                      << vm["regression"].as<bool>() << ".\n";
         }
         else
         {
diff --git a/tests/2d_examples/test_2d_airfoil/CMakeLists.txt b/tests/2d_examples/test_2d_airfoil/CMakeLists.txt
index 99b3a3f7d7..3d90cbeea6 100644
--- a/tests/2d_examples/test_2d_airfoil/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_airfoil/CMakeLists.txt
@@ -21,6 +21,6 @@ set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "
 target_link_libraries(${PROJECT_NAME} sphinxsys_2d)
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation
-     COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+     COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
      WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 set_tests_properties(${PROJECT_NAME}_particle_relaxation PROPERTIES LABELS "particle relaxation")
diff --git a/tests/2d_examples/test_2d_ball_shell_collision/CMakeLists.txt b/tests/2d_examples/test_2d_ball_shell_collision/CMakeLists.txt
index 7a01241476..a0687b71a9 100644
--- a/tests/2d_examples/test_2d_ball_shell_collision/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_ball_shell_collision/CMakeLists.txt
@@ -19,9 +19,9 @@ ADD_EXECUTABLE(${PROJECT_NAME} ${DIR_SRCS})
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 target_link_libraries(${PROJECT_NAME} sphinxsys_2d)
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "particle_relaxation, thick_surface, solid_dynamics, contact")
diff --git a/tests/2d_examples/test_2d_collision/CMakeLists.txt b/tests/2d_examples/test_2d_collision/CMakeLists.txt
index da1fed2fc0..5fe3648448 100644
--- a/tests/2d_examples/test_2d_collision/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_collision/CMakeLists.txt
@@ -19,7 +19,7 @@ ADD_EXECUTABLE(${PROJECT_NAME} ${DIR_SRCS})
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 target_link_libraries(${PROJECT_NAME} sphinxsys_2d)
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/2d_examples/test_2d_eulerian_flow_around_cylinder/CMakeLists.txt b/tests/2d_examples/test_2d_eulerian_flow_around_cylinder/CMakeLists.txt
index eb626b0635..10f25aa7d8 100644
--- a/tests/2d_examples/test_2d_eulerian_flow_around_cylinder/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_eulerian_flow_around_cylinder/CMakeLists.txt
@@ -17,10 +17,10 @@ target_link_libraries(${PROJECT_NAME} extra_sources_2d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation
-    COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+    COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 add_test(NAME ${PROJECT_NAME}
-    COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+    COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "periodic boundary, Eulerian")
diff --git a/tests/2d_examples/test_2d_flow_around_cylinder/CMakeLists.txt b/tests/2d_examples/test_2d_flow_around_cylinder/CMakeLists.txt
index 80da4f283b..791573d1ad 100644
--- a/tests/2d_examples/test_2d_flow_around_cylinder/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_flow_around_cylinder/CMakeLists.txt
@@ -18,9 +18,9 @@ file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/regression_test_tool/ DESTINATION ${BUILD_
 aux_source_directory(. DIR_SRCS)
 ADD_EXECUTABLE(${PROJECT_NAME} ${EXECUTABLE_OUTPUT_PATH} ${DIR_SRCS})
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "periodic boundary")
diff --git a/tests/2d_examples/test_2d_free_stream_around_cylinder/CMakeLists.txt b/tests/2d_examples/test_2d_free_stream_around_cylinder/CMakeLists.txt
index 04b29a4e18..704b23c738 100644
--- a/tests/2d_examples/test_2d_free_stream_around_cylinder/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_free_stream_around_cylinder/CMakeLists.txt
@@ -17,9 +17,9 @@ file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/regression_test_tool/ DESTINATION ${BUILD_
 aux_source_directory(. DIR_SRCS)
 ADD_EXECUTABLE(${PROJECT_NAME} ${EXECUTABLE_OUTPUT_PATH} ${DIR_SRCS})
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "periodic boundary, free stream")
diff --git a/tests/2d_examples/test_2d_free_stream_around_cylinder_mr/CMakeLists.txt b/tests/2d_examples/test_2d_free_stream_around_cylinder_mr/CMakeLists.txt
index 04b29a4e18..704b23c738 100644
--- a/tests/2d_examples/test_2d_free_stream_around_cylinder_mr/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_free_stream_around_cylinder_mr/CMakeLists.txt
@@ -17,9 +17,9 @@ file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/regression_test_tool/ DESTINATION ${BUILD_
 aux_source_directory(. DIR_SRCS)
 ADD_EXECUTABLE(${PROJECT_NAME} ${EXECUTABLE_OUTPUT_PATH} ${DIR_SRCS})
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "periodic boundary, free stream")
diff --git a/tests/2d_examples/test_2d_fsi2/CMakeLists.txt b/tests/2d_examples/test_2d_fsi2/CMakeLists.txt
index 4ca3a9cfd5..8c3ec3ab56 100644
--- a/tests/2d_examples/test_2d_fsi2/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_fsi2/CMakeLists.txt
@@ -16,9 +16,9 @@ file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/regression_test_tool/ DESTINATION ${BUILD_
 aux_source_directory(. DIR_SRCS)
 ADD_EXECUTABLE(${PROJECT_NAME} ${DIR_SRCS})
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "periodic boundary")
diff --git a/tests/2d_examples/test_2d_shell_beam_collision/src/CMakeLists.txt b/tests/2d_examples/test_2d_shell_beam_collision/src/CMakeLists.txt
index 206ae228bc..64d2eb9a13 100644
--- a/tests/2d_examples/test_2d_shell_beam_collision/src/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_shell_beam_collision/src/CMakeLists.txt
@@ -10,9 +10,9 @@ SET(BUILD_RELOAD_PATH "${EXECUTABLE_OUTPUT_PATH}/reload")
 aux_source_directory(. DIR_SRCS)
 ADD_EXECUTABLE(${PROJECT_NAME} ${DIR_SRCS})
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "contact, Simbody")
diff --git a/tests/2d_examples/test_2d_taylor_green/CMakeLists.txt b/tests/2d_examples/test_2d_taylor_green/CMakeLists.txt
index ba6ff7df69..eef5a13469 100644
--- a/tests/2d_examples/test_2d_taylor_green/CMakeLists.txt
+++ b/tests/2d_examples/test_2d_taylor_green/CMakeLists.txt
@@ -20,7 +20,7 @@ ADD_EXECUTABLE(${PROJECT_NAME} ${DIR_SRCS})
 
 add_test(NAME ${PROJECT_NAME}_lattice COMMAND ${PROJECT_NAME} --state_recording=${TEST_STATE_RECORDING}
   WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --reload=true --state_recording=${TEST_STATE_RECORDING}
   WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
diff --git a/tests/3d_examples/test_3d_elasticSolid_shell_collision/CMakeLists.txt b/tests/3d_examples/test_3d_elasticSolid_shell_collision/CMakeLists.txt
index f559e6cebc..de67e4b491 100644
--- a/tests/3d_examples/test_3d_elasticSolid_shell_collision/CMakeLists.txt
+++ b/tests/3d_examples/test_3d_elasticSolid_shell_collision/CMakeLists.txt
@@ -16,9 +16,9 @@ target_sources(${PROJECT_NAME} PRIVATE ${DIR_SRCS})
 target_link_libraries(${PROJECT_NAME} sphinxsys_3d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
 
diff --git a/tests/3d_examples/test_3d_heart_electromechanics/CMakeLists.txt b/tests/3d_examples/test_3d_heart_electromechanics/CMakeLists.txt
index 03f607fc7d..07452eebdd 100644
--- a/tests/3d_examples/test_3d_heart_electromechanics/CMakeLists.txt
+++ b/tests/3d_examples/test_3d_heart_electromechanics/CMakeLists.txt
@@ -17,9 +17,9 @@ target_sources(${PROJECT_NAME} PRIVATE ${DIR_SRCS})
 target_link_libraries(${PROJECT_NAME} sphinxsys_3d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
diff --git a/tests/3d_examples/test_3d_heart_volume_change/CMakeLists.txt b/tests/3d_examples/test_3d_heart_volume_change/CMakeLists.txt
index 03f607fc7d..07452eebdd 100644
--- a/tests/3d_examples/test_3d_heart_volume_change/CMakeLists.txt
+++ b/tests/3d_examples/test_3d_heart_volume_change/CMakeLists.txt
@@ -17,9 +17,9 @@ target_sources(${PROJECT_NAME} PRIVATE ${DIR_SRCS})
 target_link_libraries(${PROJECT_NAME} sphinxsys_3d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
diff --git a/tests/3d_examples/test_3d_pkj_lv_electrocontraction/CMakeLists.txt b/tests/3d_examples/test_3d_pkj_lv_electrocontraction/CMakeLists.txt
index 9a442369ce..c8e93097e0 100644
--- a/tests/3d_examples/test_3d_pkj_lv_electrocontraction/CMakeLists.txt
+++ b/tests/3d_examples/test_3d_pkj_lv_electrocontraction/CMakeLists.txt
@@ -16,9 +16,9 @@ target_sources(${PROJECT_NAME} PRIVATE ${DIR_SRCS})
 target_link_libraries(${PROJECT_NAME} sphinxsys_3d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
      WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
      WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
diff --git a/tests/3d_examples/test_3d_self_contact/CMakeLists.txt b/tests/3d_examples/test_3d_self_contact/CMakeLists.txt
index 7af5a718d6..791382e08e 100644
--- a/tests/3d_examples/test_3d_self_contact/CMakeLists.txt
+++ b/tests/3d_examples/test_3d_self_contact/CMakeLists.txt
@@ -16,9 +16,9 @@ target_sources(${PROJECT_NAME} PRIVATE ${DIR_SRCS})
 target_link_libraries(${PROJECT_NAME} sphinxsys_3d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
diff --git a/tests/3d_examples/test_3d_taylor_bar/CMakeLists.txt b/tests/3d_examples/test_3d_taylor_bar/CMakeLists.txt
index de70716a8f..a7924438eb 100644
--- a/tests/3d_examples/test_3d_taylor_bar/CMakeLists.txt
+++ b/tests/3d_examples/test_3d_taylor_bar/CMakeLists.txt
@@ -16,9 +16,9 @@ target_sources(${PROJECT_NAME} PRIVATE ${DIR_SRCS})
 target_link_libraries(${PROJECT_NAME} sphinxsys_3d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
diff --git a/tests/unit_tests_src/for_3D_build/geometrices/test_3d_geometric_shape/CMakeLists.txt b/tests/unit_tests_src/for_3D_build/geometrices/test_3d_geometric_shape/CMakeLists.txt
index 588f056e5f..d9a298a2e7 100644
--- a/tests/unit_tests_src/for_3D_build/geometrices/test_3d_geometric_shape/CMakeLists.txt
+++ b/tests/unit_tests_src/for_3D_build/geometrices/test_3d_geometric_shape/CMakeLists.txt
@@ -12,5 +12,5 @@ target_link_libraries(${PROJECT_NAME} sphinxsys_3d GTest::gtest GTest::gtest_mai
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation 
-		 COMMAND ${PROJECT_NAME} --r=true
+		 COMMAND ${PROJECT_NAME} --relax=true
 		 WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/unit_tests_src/shared/common/test_scalar_functions/CMakeLists.txt b/tests/unit_tests_src/shared/common/test_scalar_functions/CMakeLists.txt
index 588f056e5f..d9a298a2e7 100644
--- a/tests/unit_tests_src/shared/common/test_scalar_functions/CMakeLists.txt
+++ b/tests/unit_tests_src/shared/common/test_scalar_functions/CMakeLists.txt
@@ -12,5 +12,5 @@ target_link_libraries(${PROJECT_NAME} sphinxsys_3d GTest::gtest GTest::gtest_mai
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation 
-		 COMMAND ${PROJECT_NAME} --r=true
+		 COMMAND ${PROJECT_NAME} --relax=true
 		 WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/unit_tests_src/shared/common/test_sph_data_containers/CMakeLists.txt b/tests/unit_tests_src/shared/common/test_sph_data_containers/CMakeLists.txt
index 588f056e5f..d9a298a2e7 100644
--- a/tests/unit_tests_src/shared/common/test_sph_data_containers/CMakeLists.txt
+++ b/tests/unit_tests_src/shared/common/test_sph_data_containers/CMakeLists.txt
@@ -12,5 +12,5 @@ target_link_libraries(${PROJECT_NAME} sphinxsys_3d GTest::gtest GTest::gtest_mai
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation 
-		 COMMAND ${PROJECT_NAME} --r=true
+		 COMMAND ${PROJECT_NAME} --relax=true
 		 WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/unit_tests_src/shared/common/test_vector_functions/CMakeLists.txt b/tests/unit_tests_src/shared/common/test_vector_functions/CMakeLists.txt
index 588f056e5f..d9a298a2e7 100644
--- a/tests/unit_tests_src/shared/common/test_vector_functions/CMakeLists.txt
+++ b/tests/unit_tests_src/shared/common/test_vector_functions/CMakeLists.txt
@@ -12,5 +12,5 @@ target_link_libraries(${PROJECT_NAME} sphinxsys_3d GTest::gtest GTest::gtest_mai
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation 
-		 COMMAND ${PROJECT_NAME} --r=true
+		 COMMAND ${PROJECT_NAME} --relax=true
 		 WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/unit_tests_src/shared/geometries/test_complex_shape/CMakeLists.txt b/tests/unit_tests_src/shared/geometries/test_complex_shape/CMakeLists.txt
index 588f056e5f..d9a298a2e7 100644
--- a/tests/unit_tests_src/shared/geometries/test_complex_shape/CMakeLists.txt
+++ b/tests/unit_tests_src/shared/geometries/test_complex_shape/CMakeLists.txt
@@ -12,5 +12,5 @@ target_link_libraries(${PROJECT_NAME} sphinxsys_3d GTest::gtest GTest::gtest_mai
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation 
-		 COMMAND ${PROJECT_NAME} --r=true
+		 COMMAND ${PROJECT_NAME} --relax=true
 		 WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/unit_tests_src/shared/particle_dynamics/solid_dynamics/test_thin_structure_dynamics/CMakeLists.txt b/tests/unit_tests_src/shared/particle_dynamics/solid_dynamics/test_thin_structure_dynamics/CMakeLists.txt
index 588f056e5f..d9a298a2e7 100644
--- a/tests/unit_tests_src/shared/particle_dynamics/solid_dynamics/test_thin_structure_dynamics/CMakeLists.txt
+++ b/tests/unit_tests_src/shared/particle_dynamics/solid_dynamics/test_thin_structure_dynamics/CMakeLists.txt
@@ -12,5 +12,5 @@ target_link_libraries(${PROJECT_NAME} sphinxsys_3d GTest::gtest GTest::gtest_mai
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation 
-		 COMMAND ${PROJECT_NAME} --r=true
+		 COMMAND ${PROJECT_NAME} --relax=true
 		 WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/unit_tests_src/shared/test_kernels/test_kernel_cubic_B_spline/CMakeLists.txt b/tests/unit_tests_src/shared/test_kernels/test_kernel_cubic_B_spline/CMakeLists.txt
index 588f056e5f..d9a298a2e7 100644
--- a/tests/unit_tests_src/shared/test_kernels/test_kernel_cubic_B_spline/CMakeLists.txt
+++ b/tests/unit_tests_src/shared/test_kernels/test_kernel_cubic_B_spline/CMakeLists.txt
@@ -12,5 +12,5 @@ target_link_libraries(${PROJECT_NAME} sphinxsys_3d GTest::gtest GTest::gtest_mai
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation 
-		 COMMAND ${PROJECT_NAME} --r=true
+		 COMMAND ${PROJECT_NAME} --relax=true
 		 WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/unit_tests_src/shared/test_vonMisesStrain/CMakeLists.txt b/tests/unit_tests_src/shared/test_vonMisesStrain/CMakeLists.txt
index 588f056e5f..d9a298a2e7 100644
--- a/tests/unit_tests_src/shared/test_vonMisesStrain/CMakeLists.txt
+++ b/tests/unit_tests_src/shared/test_vonMisesStrain/CMakeLists.txt
@@ -12,5 +12,5 @@ target_link_libraries(${PROJECT_NAME} sphinxsys_3d GTest::gtest GTest::gtest_mai
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation 
-		 COMMAND ${PROJECT_NAME} --r=true
+		 COMMAND ${PROJECT_NAME} --relax=true
 		 WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/user_examples/extra_src/shared/wetting_coupled_spatial_temporal_method.cpp b/tests/user_examples/extra_src/shared/wetting_coupled_spatial_temporal_method.cpp
index 037b7be579..efc7ea5716 100644
--- a/tests/user_examples/extra_src/shared/wetting_coupled_spatial_temporal_method.cpp
+++ b/tests/user_examples/extra_src/shared/wetting_coupled_spatial_temporal_method.cpp
@@ -2,14 +2,13 @@
 
 namespace SPH
 {
-//=====================================================================================================//
 namespace fluid_dynamics
 {
 //=================================================================================================//
 NonWettingSurfaceIndication::
     NonWettingSurfaceIndication(BaseInnerRelation &inner_relation,
-                                               BaseContactRelation &contact_relation, Real threshold, Real criterion)
-    : FreeSurfaceIndicationComplex(inner_relation, contact_relation, threshold), wetting_criterion(criterion)
+                                BaseContactRelation &contact_relation, Real threshold)
+    : FreeSurfaceIndicationComplex(inner_relation, contact_relation, threshold)
 {
     for (size_t k = 0; k != contact_particles_.size(); ++k)
     {
@@ -18,12 +17,10 @@ NonWettingSurfaceIndication::
 }
 //=================================================================================================//
 NonWettingSurfaceIndication::
-    NonWettingSurfaceIndication(ComplexRelation &complex_relation, Real threshold, Real criterion)
+    NonWettingSurfaceIndication(ComplexRelation &complex_relation, Real threshold)
     : NonWettingSurfaceIndication(complex_relation.getInnerRelation(),
-                                                 complex_relation.getContactRelation(), threshold, criterion) {}
+                                  complex_relation.getContactRelation(), threshold) {}
 
 //=================================================================================================//
 } // namespace fluid_dynamics
-  //=================================================================================================//
 } // namespace SPH
-  //=================================================================================================//
\ No newline at end of file
diff --git a/tests/user_examples/extra_src/shared/wetting_coupled_spatial_temporal_method.h b/tests/user_examples/extra_src/shared/wetting_coupled_spatial_temporal_method.h
index bed6605bfd..29e0fb6d54 100644
--- a/tests/user_examples/extra_src/shared/wetting_coupled_spatial_temporal_method.h
+++ b/tests/user_examples/extra_src/shared/wetting_coupled_spatial_temporal_method.h
@@ -40,16 +40,16 @@ namespace fluid_dynamics
 /**
  * @class NonWettingSurfaceIndication
  * @brief Non wetting surface particles include free-surface ones and interfacial ones near the non-wetted structure.
- * @brief Even the position divergence of interfacial fluid pariticles has satisfied with the threshold of spatial-temporal 
-   identification approach to be identified as internal ones,they will remain as free-surface ones if without 
+ * @brief Even the position divergence of interfacial fluid pariticles has satisfied with the threshold of spatial-temporal
+   identification approach to be identified as internal ones,they will remain as free-surface ones if without
    any wetted neighboring solid particles.
  */
 class NonWettingSurfaceIndication : public FreeSurfaceIndicationComplex
 {
   public:
     NonWettingSurfaceIndication(BaseInnerRelation &inner_relation,
-                                               BaseContactRelation &contact_relation, Real threshold = 0.75, Real criterion = 0.99);
-    explicit NonWettingSurfaceIndication(ComplexRelation &complex_relation, Real threshold = 0.75, Real criterion = 0.99);
+                                BaseContactRelation &contact_relation, Real threshold = 0.75);
+    explicit NonWettingSurfaceIndication(ComplexRelation &complex_relation, Real threshold = 0.75);
     virtual ~NonWettingSurfaceIndication(){};
 
     inline void interaction(size_t index_i, Real dt = 0.0)
@@ -59,40 +59,18 @@ class NonWettingSurfaceIndication : public FreeSurfaceIndicationComplex
         Real pos_div = 0.0;
         for (size_t k = 0; k < contact_configuration_.size(); ++k)
         {
+            StdLargeVec<Real> &wetting_k = *(contact_phi_[k]);
             Neighborhood &contact_neighborhood = (*contact_configuration_[k])[index_i];
             for (size_t n = 0; n != contact_neighborhood.current_size_; ++n)
             {
-                pos_div -= contact_neighborhood.dW_ijV_j_[n] * contact_neighborhood.r_ij_[n];
+                size_t index_j = contact_neighborhood.j_[n];
+                pos_div -= wetting_k[index_j] * contact_neighborhood.dW_ijV_j_[n] * contact_neighborhood.r_ij_[n];
             }
         }
         pos_div_[index_i] += pos_div;
-
-        if (pos_div_[index_i] > this->threshold_by_dimensions_)
-        {
-            for (size_t k = 0; k < contact_configuration_.size(); ++k)
-            {
-                Neighborhood &contact_neighborhood = (*contact_configuration_[k])[index_i];
-                for (size_t n = 0; n != contact_neighborhood.current_size_; ++n)
-                {
-                    size_t j = contact_neighborhood.j_[n];
-                    if ((*(contact_phi_[k]))[j] > wetting_criterion)
-                    {
-                        pos_div_[index_i] = 2.0 * this->threshold_by_dimensions_;
-                        break;
-                    }
-                    else
-                    {
-                        pos_div_[index_i] = 0.5 * this->threshold_by_dimensions_;
-                    }
-                }
-                if (pos_div_[index_i] == 2.0 * this->threshold_by_dimensions_)
-                    break;
-            }
-        }
     };
 
   protected:
-    Real wetting_criterion;
     StdVec<StdLargeVec<Real> *> contact_phi_;
 };
 
@@ -101,7 +79,6 @@ using WettingCoupledSpatialTemporalFreeSurfaceIdentificationComplex =
 using SpatialTemporalFreeSurfaceIdentificationComplex =
     SpatialTemporalFreeSurfaceIdentification<FreeSurfaceIndicationComplex>;
 
-
 } // namespace fluid_dynamics
 } // namespace SPH
-#endif // WETTING_COUPLED_SPATIAL_TEMPORAL_COMPLEX_H
\ No newline at end of file
+#endif // WETTING_COUPLED_SPATIAL_TEMPORAL_COMPLEX_H
diff --git a/tests/user_examples/test_2d_FVM_double_mach_reflection/CMakeLists.txt b/tests/user_examples/test_2d_FVM_double_mach_reflection/CMakeLists.txt
index 910a98f24c..221d65a8d4 100644
--- a/tests/user_examples/test_2d_FVM_double_mach_reflection/CMakeLists.txt
+++ b/tests/user_examples/test_2d_FVM_double_mach_reflection/CMakeLists.txt
@@ -17,10 +17,10 @@ target_link_libraries(${PROJECT_NAME} extra_sources_2d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation
-        COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+        COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 add_test(NAME ${PROJECT_NAME}
-        COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+        COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "periodic boundary, Eulerian")
diff --git a/tests/user_examples/test_2d_FVM_flow_around_cylinder/CMakeLists.txt b/tests/user_examples/test_2d_FVM_flow_around_cylinder/CMakeLists.txt
index 831d16d20b..88419ca5e9 100644
--- a/tests/user_examples/test_2d_FVM_flow_around_cylinder/CMakeLists.txt
+++ b/tests/user_examples/test_2d_FVM_flow_around_cylinder/CMakeLists.txt
@@ -19,10 +19,10 @@ target_link_libraries(${PROJECT_NAME} extra_sources_2d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation
-        COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+        COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 add_test(NAME ${PROJECT_NAME}
-        COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+        COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "periodic boundary, Eulerian")
diff --git a/tests/user_examples/test_2d_eulerian_flow_around_cylinder_LG/CMakeLists.txt b/tests/user_examples/test_2d_eulerian_flow_around_cylinder_LG/CMakeLists.txt
index a0fba24567..911d077bdb 100644
--- a/tests/user_examples/test_2d_eulerian_flow_around_cylinder_LG/CMakeLists.txt
+++ b/tests/user_examples/test_2d_eulerian_flow_around_cylinder_LG/CMakeLists.txt
@@ -17,10 +17,10 @@ target_link_libraries(${PROJECT_NAME} extra_sources_2d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
 add_test(NAME ${PROJECT_NAME}_particle_relaxation
-     COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+     COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
      WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 add_test(NAME ${PROJECT_NAME}
-     COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+     COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
      WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 set_tests_properties(${PROJECT_NAME} PROPERTIES DEPENDS "${PROJECT_NAME}_particle_relaxation")
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "periodic boundary, Eulerian")
diff --git a/tests/user_examples/test_2d_flow_stream_around_fish/CMakeLists.txt b/tests/user_examples/test_2d_flow_stream_around_fish/CMakeLists.txt
index 67afd07e84..740499fdcf 100644
--- a/tests/user_examples/test_2d_flow_stream_around_fish/CMakeLists.txt
+++ b/tests/user_examples/test_2d_flow_stream_around_fish/CMakeLists.txt
@@ -13,9 +13,9 @@ SET(BUILD_RELOAD_PATH "${EXECUTABLE_OUTPUT_PATH}/reload")
 aux_source_directory(. DIR_SRCS)
 ADD_EXECUTABLE(${PROJECT_NAME} ${DIR_SRCS})
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
diff --git a/tests/user_examples/xj_stretching/CMakeLists.txt b/tests/user_examples/test_2d_stretching/CMakeLists.txt
similarity index 66%
rename from tests/user_examples/xj_stretching/CMakeLists.txt
rename to tests/user_examples/test_2d_stretching/CMakeLists.txt
index 7434f894db..63dd6a3ac8 100644
--- a/tests/user_examples/xj_stretching/CMakeLists.txt
+++ b/tests/user_examples/test_2d_stretching/CMakeLists.txt
@@ -22,14 +22,7 @@ target_link_libraries(${PROJECT_NAME} extra_sources_2d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
  
-if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-    add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
                      WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-    add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
                      WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-else()
-    file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/run_test.sh
-            DESTINATION ${EXECUTABLE_OUTPUT_PATH})
-    add_test(NAME ${PROJECT_NAME} COMMAND bash ${EXECUTABLE_OUTPUT_PATH}/run_test.sh
-            WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-endif()
diff --git a/tests/user_examples/test_2d_stretching/stretching.cpp b/tests/user_examples/test_2d_stretching/stretching.cpp
new file mode 100644
index 0000000000..8175e0aaf9
--- /dev/null
+++ b/tests/user_examples/test_2d_stretching/stretching.cpp
@@ -0,0 +1,367 @@
+/* ---------------------------------------------------------------------------*
+ *            SPHinXsys: 2D oscillation beam example-one body version           *
+ * ----------------------------------------------------------------------------*
+ * This is the one of the basic test cases, also the first case for            *
+ * understanding SPH method for solid simulation.                              *
+ * In this case, the constraint of the beam is implemented with                *
+ * internal constrained subregion.                                             *
+ * ----------------------------------------------------------------------------*/
+#include "inelastic_solid_hardening.h"
+#include "sphinxsys.h"
+
+using namespace SPH;
+//------------------------------------------------------------------------------
+// global parameters for the case
+//------------------------------------------------------------------------------
+Real PL = 0.05334;  // beam length
+Real PH = 0.012826; // for thick plate;
+
+// reference particle spacing
+Real resolution_ref = PH / 30;
+Real BW = resolution_ref * 4.0; // boundary width, at least three particles
+
+/** Domain bounds of the system. */
+BoundingBox system_domain_bounds(Vec2d(-PL / 2.0, -PL / 2.0),
+                                 Vec2d(2.0 * PL, PL / 2.0));
+// two dimensional should be circle smooth between two parts.
+//----------------------------------------------------------------------
+Real rho0_s = 7850.0;           /**< Reference density. */
+Real Shear_modulus = 80.1938e9; /**< Poisson ratio. */
+Real Bulk_modulus = 164.21e9;
+
+Real poisson = (3.0 * Bulk_modulus - 2.0 * Shear_modulus) / (6.0 * Bulk_modulus + 2.0 * Shear_modulus); /**< Poisson ratio. */
+Real Youngs_modulus = (9.0 * Shear_modulus * Bulk_modulus) / (3.0 * Bulk_modulus + Shear_modulus);
+
+Real yield_stress = 0.45e9;
+Real hardening_modulus = 1.2924e8;
+Real saturation_flow_stress = 7.15e8;
+Real saturation_exponent = 16.93;
+
+Real physical_viscosity = 1.0e4;
+Real refer_energy = 0.5 * 8000 * 0.01; // 40
+
+Vecd norm_(1.0, 0.0);
+Vecd upper_face_point_(0.02 + 3.0 * resolution_ref, 0.0);
+Vecd lower_face_point_(0.02, 0.0);
+
+Vecd norm_4(1.0, 0.0);
+Vecd upper_face_point_4(0.04 + 3.0 * resolution_ref, 0.0);
+Vecd lower_face_point_4(0.04, 0.0);
+
+// Beam observer location
+StdVec<Vecd> observation_location = {Vecd(PL / 2.0, PH / 2.0 - PH * 0.01)};
+
+//----------------------------------------------------------------------
+//	Geometric shapes used in the system.
+//----------------------------------------------------------------------
+
+std::vector<Vecd> beam_left_stretch_shape{
+    Vecd(-BW, -PH / 2), Vecd(-BW, PH / 2), Vecd(0.0, PH / 2),
+    Vecd(0.0, -PH / 2), Vecd(-BW, -PH / 2)};
+
+// a beam shape
+std::vector<Vecd> beam_shape{
+    Vecd(0.0, -PH / 2), Vecd(0.0, PH / 2),
+    Vecd(PL / 2.0, PH / 2 - PH * 0.01),
+    Vecd(PL, PH / 2), Vecd(PL, -PH / 2),
+    Vecd(PL / 2.0, -PH / 2 + PH * 0.01),
+    Vecd(0.0, -PH / 2)};
+
+std::vector<Vecd> beam_right_stretch_shape{
+    Vecd(PL, -PH / 2), Vecd(PL, PH / 2), Vecd(PL + BW, PH / 2),
+    Vecd(PL + BW, -PH / 2), Vecd(PL, -PH / 2)};
+
+//----------------------------------------------------------------------
+//	Define the beam body
+//----------------------------------------------------------------------
+class Beam : public MultiPolygonShape
+{
+  public:
+    explicit Beam(const std::string &shape_name) : MultiPolygonShape(shape_name)
+    {
+        multi_polygon_.addAPolygon(beam_right_stretch_shape, ShapeBooleanOps::add);
+        multi_polygon_.addAPolygon(beam_shape, ShapeBooleanOps::add);
+        multi_polygon_.addAPolygon(beam_left_stretch_shape, ShapeBooleanOps::add);
+    }
+};
+
+class LeftStretchSolidBodyRegion : public solid_dynamics::BaseMotionConstraint<BodyPartByParticle>
+{
+  public:
+    // TODO: use only body part as argment since body can be referred from it already
+    LeftStretchSolidBodyRegion(BodyPartByParticle &body_part)
+        : solid_dynamics::BaseMotionConstraint<BodyPartByParticle>(body_part),
+          vel_(particles_->vel_), pos_(particles_->pos_){};
+
+    virtual ~LeftStretchSolidBodyRegion(){};
+
+  protected:
+    StdLargeVec<Vecd> &vel_;
+    StdLargeVec<Vecd> &pos_;
+    virtual void update(size_t index_i, Real Dt = 0.0)
+    {
+        pos_[index_i][0] -= 0.5e-4 * Dt;
+    };
+};
+
+class RightStretchSolidBodyRegion : public solid_dynamics::BaseMotionConstraint<BodyPartByParticle>
+{
+  public:
+    // TODO: use only body part as argment since body can be referred from it already
+    RightStretchSolidBodyRegion(BodyPartByParticle &body_part)
+        : solid_dynamics::BaseMotionConstraint<BodyPartByParticle>(body_part),
+          vel_(particles_->vel_), pos_(particles_->pos_){};
+
+    virtual ~RightStretchSolidBodyRegion(){};
+
+  protected:
+    StdLargeVec<Vecd> &vel_;
+    StdLargeVec<Vecd> &pos_;
+    virtual void update(size_t index_i, Real Dt = 0.0)
+    {
+        pos_[index_i][0] += 0.5e-4 * Dt;
+    };
+};
+
+MultiPolygon createBeamRightStretchShape()
+{
+    MultiPolygon multi_polygon;
+    multi_polygon.addAPolygon(beam_right_stretch_shape, ShapeBooleanOps::add);
+    return multi_polygon;
+};
+
+MultiPolygon createBeamLeftStretchShape()
+{
+    MultiPolygon multi_polygon;
+    multi_polygon.addAPolygon(beam_left_stretch_shape, ShapeBooleanOps::add);
+    return multi_polygon;
+};
+
+MultiPolygon createConstrainBeamShape()
+{
+    MultiPolygon multi_polygon;
+    multi_polygon.addAPolygon(beam_left_stretch_shape, ShapeBooleanOps::add);
+    multi_polygon.addAPolygon(beam_right_stretch_shape, ShapeBooleanOps::add);
+
+    return multi_polygon;
+};
+
+class ConstrainXVelocity : public solid_dynamics::BaseMotionConstraint<BodyPartByParticle>
+{
+  public:
+    // TODO: use only body part as argment since body can be referred from it already
+    ConstrainXVelocity(BodyPartByParticle &body_part)
+        : solid_dynamics::BaseMotionConstraint<BodyPartByParticle>(body_part),
+          vel_(particles_->vel_), pos_(particles_->pos_){};
+
+    virtual ~ConstrainXVelocity(){};
+
+  protected:
+    StdLargeVec<Vecd> &vel_;
+    StdLargeVec<Vecd> &pos_;
+    virtual void update(size_t index_i, Real dt = 0.0)
+    {
+        vel_[index_i] = Vecd(0.0, vel_[index_i][1]);
+    };
+};
+
+//------------------------------------------------------------------------------
+// the main program
+//------------------------------------------------------------------------------
+int main(int ac, char *av[])
+{
+    //----------------------------------------------------------------------
+    //	Build up the environment of a SPHSystem with global controls.
+    //----------------------------------------------------------------------
+    SPHSystem system(system_domain_bounds, resolution_ref);
+    /** Tag for running particle relaxation for the initially body-fitted distribution */
+    system.setRunParticleRelaxation(false);
+    /** Tag for starting with relaxed body-fitted particles distribution */
+    system.setReloadParticles(true);
+    system.handleCommandlineOptions(ac, av);
+    IOEnvironment io_environment(system);
+
+    //----------------------------------------------------------------------
+    //	Creating body, materials and particles.
+    //----------------------------------------------------------------------
+    SolidBody beam_body(system, makeShared<Beam>("StretchingBody"));
+    beam_body.defineBodyLevelSetShape();
+    beam_body.defineParticlesAndMaterial<ElasticSolidParticles, NonLinearHardeningPlasticSolid>(
+        rho0_s, Youngs_modulus, poisson, yield_stress, hardening_modulus, saturation_flow_stress, saturation_exponent);
+
+    (!system.RunParticleRelaxation() && system.ReloadParticles())
+        ? beam_body.generateParticles<ParticleGeneratorReload>(io_environment, beam_body.getName())
+        : beam_body.generateParticles<ParticleGeneratorLattice>();
+
+    ObserverBody beam_observer(system, "BeamObserver");
+    beam_observer.generateParticles<ObserverParticleGenerator>(observation_location);
+    //----------------------------------------------------------------------
+    //	Define body relation map.
+    //	The contact map gives the topological connections between the bodies.
+    //	Basically the the range of bodies to build neighbor particle lists.
+    //----------------------------------------------------------------------
+    if (system.RunParticleRelaxation())
+    {
+        //----------------------------------------------------------------------
+        //	Define body relation map used for particle relaxation.
+        //----------------------------------------------------------------------
+        InnerRelation beam_body_inner(beam_body);
+        //----------------------------------------------------------------------
+        //	Define the methods for particle relaxation.
+        //----------------------------------------------------------------------
+        SimpleDynamics<RandomizeParticlePosition> beam_body_random_particles(beam_body);
+        relax_dynamics::RelaxationStepInner beam_body_relaxation_step_inner(beam_body_inner);
+        //----------------------------------------------------------------------
+        //	Output for particle relaxation.
+        //----------------------------------------------------------------------
+        BodyStatesRecordingToVtp write_ball_state(io_environment, system.real_bodies_);
+        ReloadParticleIO write_particle_reload_files(io_environment, {&beam_body});
+        //----------------------------------------------------------------------
+        //	Particle relaxation starts here.
+        //----------------------------------------------------------------------
+        beam_body_random_particles.exec(0.25);
+        write_ball_state.writeToFile(0);
+        //----------------------------------------------------------------------
+        //	From here iteration for particle relaxation begins.
+        //----------------------------------------------------------------------
+        int ite = 0;
+        int relax_step = 1000;
+        while (ite < relax_step)
+        {
+            beam_body_relaxation_step_inner.exec();
+            ite += 1;
+            if (ite % 100 == 0)
+            {
+                std::cout << std::fixed << std::setprecision(9) << "Relaxation steps N = " << ite << "\n";
+                write_ball_state.writeToFile(ite);
+            }
+        }
+        std::cout << "The physics relaxation process of particles finish !" << std::endl;
+        write_particle_reload_files.writeToFile(0);
+        return 0;
+    }
+
+    InnerRelation beam_body_inner(beam_body);
+    ContactRelation beam_observer_contact(beam_observer, {&beam_body});
+    //-----------------------------------------------------------------------------
+    // this section define all numerical methods will be used in this case
+    //-----------------------------------------------------------------------------
+
+    // corrected strong configuration
+    InteractionWithUpdate<CorrectedConfigurationInner> beam_corrected_configuration(beam_body_inner);
+
+    // time step size calculation
+    ReduceDynamics<solid_dynamics::AcousticTimeStepSize> computing_time_step_size(beam_body);
+    // stress relaxation for the beam
+    Dynamics1Level<solid_dynamics::PlasticIntegration1stHalf> stress_relaxation_first_half(beam_body_inner);
+    Dynamics1Level<solid_dynamics::Integration2ndHalf> stress_relaxation_second_half(beam_body_inner);
+    ReduceDynamics<TotalMechanicalEnergy> get_kinetic_energy(beam_body);
+
+    BodyRegionByParticle beam_left_stretch(beam_body, makeShared<MultiPolygonShape>(createBeamLeftStretchShape()));
+    SimpleDynamics<LeftStretchSolidBodyRegion> stretch_beam_left_end(beam_left_stretch);
+    BodyRegionByParticle beam_right_stretch(beam_body, makeShared<MultiPolygonShape>(createBeamRightStretchShape()));
+    SimpleDynamics<RightStretchSolidBodyRegion> stretch_beam_right_end(beam_right_stretch);
+    BodyRegionByParticle beam_constrain(beam_body, makeShared<MultiPolygonShape>(createConstrainBeamShape()));
+    SimpleDynamics<ConstrainXVelocity> constrain_beam_end(beam_constrain);
+
+    InteractionDynamics<solid_dynamics::DeformationGradientBySummation> beam_deformation_gradient_tensor(beam_body_inner);
+    DampingWithRandomChoice<InteractionSplit<DampingPairwiseInner<Vec2d>>>
+        damping(0.5, beam_body_inner, "Velocity", physical_viscosity);
+
+    //-----------------------------------------------------------------------------
+    // outputs
+    //-----------------------------------------------------------------------------
+
+    BodyStatesRecordingToVtp write_beam_states(io_environment, system.real_bodies_);
+    ReducedQuantityRecording<ReduceDynamics<TotalMechanicalEnergy>>
+        write_total_mechanical_energy(io_environment, beam_body);
+    //----------------------------------------------------------------------
+    //	Setup computing and initial conditions.
+    //----------------------------------------------------------------------
+    system.initializeSystemCellLinkedLists();
+    system.initializeSystemConfigurations();
+    beam_corrected_configuration.exec();
+
+    //----------------------------------------------------------------------
+    //	Setup computing time-step controls.
+    //----------------------------------------------------------------------
+    int ite = 0;
+    int Dt_ite = 0;
+    Real End_Time = 100.0;
+
+    Real D_Time = End_Time / 100.0; // time step size for output file
+    Real Dt = End_Time / 10000.0;   /**< Time period for stretching */
+    Real dt = 0.0;                  // default acoustic time step sizes
+
+    // statistics for computing time
+    TickCount t1 = TickCount::now();
+    TimeInterval interval;
+    //-----------------------------------------------------------------------------
+    // from here the time stepping begins
+    //-----------------------------------------------------------------------------
+    write_beam_states.writeToFile(0);
+    write_total_mechanical_energy.writeToFile(0);
+
+    // computation loop starts
+    while (GlobalStaticVariables::physical_time_ < End_Time)
+    {
+        Real integration_time = 0.0;
+        // integrate time (loop) until the next output time
+        while (integration_time < D_Time)
+        {
+            Real relaxation_time = 0.0;
+            stretch_beam_left_end.exec(Dt);
+            stretch_beam_right_end.exec(Dt);
+            beam_deformation_gradient_tensor.exec(Dt);
+            Dt_ite++;
+
+            int stress_ite = 0;
+            Real refer_total_kinetic_energy = 10000.0;
+            while (relaxation_time < Dt)
+            {
+                if (refer_total_kinetic_energy > 0.005)
+                {
+                    stress_relaxation_first_half.exec(dt);
+                    constrain_beam_end.exec(dt);
+                    damping.exec(Dt);
+                    constrain_beam_end.exec(dt);
+                    stress_relaxation_second_half.exec(dt);
+
+                    refer_total_kinetic_energy = get_kinetic_energy.exec() / refer_energy;
+
+                    ite++;
+                    stress_ite++;
+
+                    dt = computing_time_step_size.exec();
+                    if (ite % 500 == 0)
+                    {
+                        std::cout << "N=" << ite << " Time: "
+                                  << GlobalStaticVariables::physical_time_
+                                  << "	Dt: " << Dt << "	dt: " << dt
+                                  << "	Dt:dt = " << Dt / dt << "\n";
+                    }
+                }
+                relaxation_time += dt;
+                integration_time += dt;
+                GlobalStaticVariables::physical_time_ += dt;
+            }
+
+            std::cout << "refer_total_kinetic_energy  " << refer_total_kinetic_energy
+                      << "    stress_ite  " << stress_ite << std::endl;
+        }
+
+        TickCount t2 = TickCount::now();
+        write_beam_states.writeToFile();
+        TickCount t3 = TickCount::now();
+        interval += t3 - t2;
+    }
+    TickCount t4 = TickCount::now();
+
+    TimeInterval tt;
+    tt = t4 - t1 - interval;
+    std::cout << "Total wall time for computation: " << tt.seconds() << " seconds."
+              << "  Iterations:  " << ite << std::endl;
+    std::cout << "Total iterations computation:  " << GlobalStaticVariables::physical_time_ / dt
+              << std::endl;
+    return 0;
+}
diff --git a/tests/user_examples/test_2d_water_entry_exit/CMakeLists.txt b/tests/user_examples/test_2d_water_entry_exit/CMakeLists.txt
index b00933fc10..e6889b272e 100644
--- a/tests/user_examples/test_2d_water_entry_exit/CMakeLists.txt
+++ b/tests/user_examples/test_2d_water_entry_exit/CMakeLists.txt
@@ -17,9 +17,9 @@ file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/regression_test_tool/ DESTINATION ${BUILD_
 aux_source_directory(. DIR_SRCS)
 ADD_EXECUTABLE(${PROJECT_NAME} ${EXECUTABLE_OUTPUT_PATH} ${DIR_SRCS})
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
     WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
 
 set_tests_properties(${PROJECT_NAME} PROPERTIES LABELS "spatial_temporal_identification")
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_0_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_0_result.xml
new file mode 100644
index 0000000000..d065a6bee5
--- /dev/null
+++ b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_0_result.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<result>
+    <Snapshot_Element>
+        <Snapshot number_of_snapshot_for_local_result_="13" />
+    </Snapshot_Element>
+    <Result_Element>
+        <Particle_0 snapshot_0="~[0.220007,0.314986]" snapshot_1="~[0.220007,0.280025]" snapshot_2="~[0.220006,0.193269]" snapshot_3="~[0.219587,0.133347]" snapshot_4="~[0.219748,0.103269]" snapshot_5="~[0.219824,0.10677]" snapshot_6="~[0.219544,0.133414]" snapshot_7="~[0.21946,0.174544]" snapshot_8="~[0.219426,0.215659]" snapshot_9="~[0.220045,0.228747]" snapshot_10="~[0.220789,0.194015]" snapshot_11="~[0.221819,0.153673]" snapshot_12="~[0.22056,0.133759]" />
+    </Result_Element>
+</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_14_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_14_result.xml
new file mode 100644
index 0000000000..fe712a2ca6
--- /dev/null
+++ b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_14_result.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<result>
+    <Snapshot_Element>
+        <Snapshot number_of_snapshot_for_local_result_="13" />
+    </Snapshot_Element>
+    <Result_Element>
+        <Particle_0 snapshot_0="~[0.220009,0.314992]" snapshot_1="~[0.220009,0.280031]" snapshot_2="~[0.220011,0.193212]" snapshot_3="~[0.22022,0.132127]" snapshot_4="~[0.220414,0.102673]" snapshot_5="~[0.220373,0.106346]" snapshot_6="~[0.220391,0.132435]" snapshot_7="~[0.220647,0.173058]" snapshot_8="~[0.22132,0.214749]" snapshot_9="~[0.223532,0.22991]" snapshot_10="~[0.225597,0.195475]" snapshot_11="~[0.225108,0.154261]" snapshot_12="~[0.225577,0.133495]" />
+    </Result_Element>
+</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_7_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_7_result.xml
new file mode 100644
index 0000000000..e05d102fb9
--- /dev/null
+++ b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_Run_7_result.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<result>
+    <Snapshot_Element>
+        <Snapshot number_of_snapshot_for_local_result_="13" />
+    </Snapshot_Element>
+    <Result_Element>
+        <Particle_0 snapshot_0="~[0.219996,0.314978]" snapshot_1="~[0.219996,0.280017]" snapshot_2="~[0.219983,0.193192]" snapshot_3="~[0.220009,0.132224]" snapshot_4="~[0.219972,0.102751]" snapshot_5="~[0.220031,0.106134]" snapshot_6="~[0.220207,0.132033]" snapshot_7="~[0.22019,0.172824]" snapshot_8="~[0.219705,0.215068]" snapshot_9="~[0.218367,0.231606]" snapshot_10="~[0.21707,0.196987]" snapshot_11="~[0.216039,0.153491]" snapshot_12="~[0.215554,0.131685]" />
+    </Result_Element>
+</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_dtwdistance.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_dtwdistance.xml
similarity index 58%
rename from tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_dtwdistance.xml
rename to tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_dtwdistance.xml
index eaf89cd547..ead45a7e4c 100644
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_dtwdistance.xml
+++ b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_dtwdistance.xml
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" ?>
 <dtw_distance>
-    <DTWDistance TotalMechanicalEnergy_0="0.2" />
+    <DTWDistance Position_0="0.15" />
 </dtw_distance>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_runtimes.dat b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_runtimes.dat
similarity index 66%
rename from tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_runtimes.dat
rename to tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_runtimes.dat
index fd8ad08880..9c41804468 100644
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_runtimes.dat
+++ b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/CylinderObserver_Position_runtimes.dat
@@ -1,3 +1,3 @@
 true
-21
+15
 4
\ No newline at end of file
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_0_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_0_result.xml
deleted file mode 100644
index 8c7499408f..0000000000
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_0_result.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<result>
-    <Snapshot_Element>
-        <Snapshot number_of_snapshot_for_local_result_="23" />
-    </Snapshot_Element>
-    <Result_Element>
-        <Particle_0 snapshot_0="0" snapshot_1="0" snapshot_2="0" snapshot_3="0.26824761949884235" snapshot_4="0.4730243946282956" snapshot_5="0.74587925241894071" snapshot_6="0.72242583246899739" snapshot_7="1.0870796359291397" snapshot_8="0.5682468472962563" snapshot_9="0.080383330251895799" snapshot_10="0.28951507448785041" snapshot_11="0.19503809881383863" snapshot_12="0.072247067621478339" snapshot_13="0.035605086322673521" snapshot_14="0.078924044748357097" snapshot_15="0.24978032310464621" snapshot_16="0.28252482137663387" snapshot_17="0.15952092372783219" snapshot_18="0.15307918833519168" snapshot_19="0.095080477191072876" snapshot_20="0.044194752631769751" snapshot_21="0.025363818478689421" snapshot_22="0.4551060768497584" />
-    </Result_Element>
-</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_10_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_10_result.xml
deleted file mode 100644
index 30e1e009d6..0000000000
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_10_result.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<result>
-    <Snapshot_Element>
-        <Snapshot number_of_snapshot_for_local_result_="23" />
-    </Snapshot_Element>
-    <Result_Element>
-        <Particle_0 snapshot_0="0" snapshot_1="0" snapshot_2="0" snapshot_3="0.26824761956935955" snapshot_4="0.47302439486463893" snapshot_5="0.74588067344078801" snapshot_6="0.72193405874996353" snapshot_7="1.1261790827731351" snapshot_8="0.59383508816735919" snapshot_9="0.25240999590614466" snapshot_10="0.30566895950967043" snapshot_11="0.17371303994787599" snapshot_12="0.10493709564791738" snapshot_13="0.040965428157454159" snapshot_14="0.073776302344906536" snapshot_15="0.25387079940163582" snapshot_16="0.2777096055007699" snapshot_17="0.18727559494591406" snapshot_18="0.15023074525997723" snapshot_19="0.094780833589947933" snapshot_20="0.049784791524005098" snapshot_21="0.028947481780696508" snapshot_22="0.77785682130437295" />
-    </Result_Element>
-</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_20_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_20_result.xml
deleted file mode 100644
index 4e82ba0c88..0000000000
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_Run_20_result.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<result>
-    <Snapshot_Element>
-        <Snapshot number_of_snapshot_for_local_result_="23" />
-    </Snapshot_Element>
-    <Result_Element>
-        <Particle_0 snapshot_0="0" snapshot_1="0" snapshot_2="0" snapshot_3="0.2682476195412844" snapshot_4="0.47302448444365897" snapshot_5="0.74588226196639718" snapshot_6="0.72228266702877364" snapshot_7="1.1256682005482554" snapshot_8="0.44350066049561476" snapshot_9="0.24926134935006949" snapshot_10="0.39149771463015298" snapshot_11="0.22487722496839638" snapshot_12="0.042894954501629716" snapshot_13="0.069398823961160275" snapshot_14="0.033657753591351001" snapshot_15="0.25189361494282553" snapshot_16="0.26230617619410124" snapshot_17="0.19596774244520693" snapshot_18="0.14535307307625736" snapshot_19="0.11183689814420757" snapshot_20="0.076086793367831168" snapshot_21="0.02834455916269147" snapshot_22="0.37818345401739356" />
-    </Result_Element>
-</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_dtwdistance.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_dtwdistance.xml
deleted file mode 100644
index 937895ceed..0000000000
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/FluidObserver_Pressure_dtwdistance.xml
+++ /dev/null
@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<dtw_distance>
-    <DTWDistance Pressure_0="1.078460056924573" />
-</dtw_distance>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_0_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_0_result.xml
deleted file mode 100644
index 040faac7d7..0000000000
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_0_result.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<result>
-    <Snapshot_Element>
-        <Snapshot number_of_snapshot_for_local_result_="23" />
-    </Snapshot_Element>
-    <Result_Element>
-        <Particle_0 snapshot_0="1.0000000000000016" snapshot_1="0.99908073979547907" snapshot_2="0.9972535745709904" snapshot_3="0.97934908582374036" snapshot_4="0.96681779377513877" snapshot_5="0.9609435530819791" snapshot_6="0.95483654608254354" snapshot_7="0.91693034033482201" snapshot_8="0.89034597029198026" snapshot_9="0.82298470556549053" snapshot_10="0.77388107898670888" snapshot_11="0.64359526718536286" snapshot_12="0.59284102898789648" snapshot_13="0.54316549181859042" snapshot_14="0.52693679182409836" snapshot_15="0.50910549193526555" snapshot_16="0.49098941767463433" snapshot_17="0.47418058373116045" snapshot_18="0.45910910872711319" snapshot_19="0.44671211083616774" snapshot_20="0.43914896846695872" snapshot_21="0.43020444713463862" snapshot_22="0.42109977970773788" />
-    </Result_Element>
-</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_11_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_11_result.xml
deleted file mode 100644
index a4f9d99f27..0000000000
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_11_result.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<result>
-    <Snapshot_Element>
-        <Snapshot number_of_snapshot_for_local_result_="23" />
-    </Snapshot_Element>
-    <Result_Element>
-        <Particle_0 snapshot_0="1.0000000000000013" snapshot_1="0.99908073979547884" snapshot_2="0.99725357457060326" snapshot_3="0.97934908582084113" snapshot_4="0.96681779390432554" snapshot_5="0.96094354739906396" snapshot_6="0.95483667401992078" snapshot_7="0.91700198965761337" snapshot_8="0.890298343167784" snapshot_9="0.82347793544468728" snapshot_10="0.77411350801162282" snapshot_11="0.64661134753812921" snapshot_12="0.59474259967521981" snapshot_13="0.54242004915481623" snapshot_14="0.52660072249066781" snapshot_15="0.51246729660496948" snapshot_16="0.4933639974490498" snapshot_17="0.47463211305291358" snapshot_18="0.46251664631840911" snapshot_19="0.45283168245170557" snapshot_20="0.44519260475260247" snapshot_21="0.43611794304528545" snapshot_22="0.42560609742829392" />
-    </Result_Element>
-</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_6_result.xml b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_6_result.xml
deleted file mode 100644
index 2b0252d34c..0000000000
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_Run_6_result.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<result>
-    <Snapshot_Element>
-        <Snapshot number_of_snapshot_for_local_result_="23" />
-    </Snapshot_Element>
-    <Result_Element>
-        <Particle_0 snapshot_0="1.0000000000000013" snapshot_1="0.99908073979548129" snapshot_2="0.99725357457195196" snapshot_3="0.97934908582514835" snapshot_4="0.9668177937724618" snapshot_5="0.96094355935347275" snapshot_6="0.95483644361309716" snapshot_7="0.9168952018698473" snapshot_8="0.89045591055620532" snapshot_9="0.82226712645025335" snapshot_10="0.7740482143577585" snapshot_11="0.64372878458122351" snapshot_12="0.59197947331431133" snapshot_13="0.53896777564558884" snapshot_14="0.52361514426760103" snapshot_15="0.50585369010145087" snapshot_16="0.48669689464087029" snapshot_17="0.47110675895795073" snapshot_18="0.45475361279453147" snapshot_19="0.44335740932927675" snapshot_20="0.43355538864165893" snapshot_21="0.42704792183618945" snapshot_22="0.41940662237264842" />
-    </Result_Element>
-</result>
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_runtimes.dat b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_runtimes.dat
deleted file mode 100644
index 5cc2fa0e29..0000000000
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/WaterBody_TotalMechanicalEnergy_runtimes.dat
+++ /dev/null
@@ -1,3 +0,0 @@
-true
-12
-4
\ No newline at end of file
diff --git a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/regression_test_tool.py b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/regression_test_tool.py
index bedffb1c37..ca702a5150 100644
--- a/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/regression_test_tool.py
+++ b/tests/user_examples/test_2d_water_entry_exit/regression_test_tool/regression_test_tool.py
@@ -7,20 +7,16 @@
 from regression_test_base_tool import SphinxsysRegressionTest
 
 """
-case name: test_2d_dambreak
+case name: test_2d_water_entry_exit
 """
 
-case_name = "test_2d_dambreak"
-body_name = "WaterBody"
-parameter_name = "TotalMechanicalEnergy"
-body_name_1 = "FluidObserver"
-parameter_name_1 = "Pressure"
+case_name = "test_2d_water_entry_exit"
+body_name = "CylinderObserver"
+parameter_name = "Position"
 
 number_of_run_times = 0
 converged = 0
 sphinxsys = SphinxsysRegressionTest(case_name, body_name, parameter_name)
-sphinxsys_1 = SphinxsysRegressionTest(case_name, body_name_1, parameter_name_1)
-
 
 while True:
     print("Now start a new run......")
@@ -28,18 +24,14 @@
     sphinxsys.run_case_with_reload()
     number_of_run_times += 1
     converged = sphinxsys.read_dat_file()
-    converged_1 = sphinxsys_1.read_dat_file()
     print("Please note: This is the", number_of_run_times, "run!")
     if number_of_run_times <= 200:
-        if (converged == "true") and (converged_1 == "true"):
+        if (converged == "true"):
             print("The tested parameters of all variables are converged, and the run will stop here!")
             break
         elif converged != "true":
             print("The tested parameters of", sphinxsys.sphinxsys_parameter_name, "are not converged!")
             continue
-        elif converged_1 != "true":
-            print("The tested parameters of", sphinxsys_1.sphinxsys_parameter_name, "are not converged!")
-            continue
     else:
         print("It's too many runs but still not converged, please try again!")
         break
diff --git a/tests/user_examples/test_2d_water_entry_exit/test_2d_water_entry_exit.cpp b/tests/user_examples/test_2d_water_entry_exit/test_2d_water_entry_exit.cpp
index 9a89aa81c7..670072f759 100644
--- a/tests/user_examples/test_2d_water_entry_exit/test_2d_water_entry_exit.cpp
+++ b/tests/user_examples/test_2d_water_entry_exit/test_2d_water_entry_exit.cpp
@@ -35,10 +35,10 @@ Real mu_f = 8.9e-7;                      /**< Water dynamics viscosity. */
 //----------------------------------------------------------------------
 //	Wetting parameters
 //----------------------------------------------------------------------
-Real diffusion_coeff = 330.578 * pow(particle_spacing_ref, 2); /**< Wetting coefficient. */
-Real fluid_moisture = 1.0;                                     /**< fluid moisture. */
-Real cylinder_moisture = 0.0;                                  /**< cylinder moisture. */
-Real wall_moisture = 1.0;                                      /**< wall moisture. */
+Real diffusion_coeff = 100.0 * pow(particle_spacing_ref, 2); /**< Wetting coefficient. */
+Real fluid_moisture = 1.0;                                   /**< fluid moisture. */
+Real cylinder_moisture = 0.0;                                /**< cylinder moisture. */
+Real wall_moisture = 1.0;                                    /**< wall moisture. */
 //----------------------------------------------------------------------
 //	Definition for water body
 //----------------------------------------------------------------------
@@ -246,8 +246,8 @@ int main(int ac, char *av[])
         ? cylinder.generateParticles<ParticleGeneratorReload>(io_environment, cylinder.getName())
         : cylinder.generateParticles<ParticleGeneratorLattice>();
 
-    ObserverBody fluid_observer(sph_system, "FluidObserver");
-    fluid_observer.generateParticles<ObserverParticleGenerator>(observer_location);
+    ObserverBody cylinder_observer(sph_system, "CylinderObserver");
+    cylinder_observer.generateParticles<ObserverParticleGenerator>(observer_location);
     //----------------------------------------------------------------------
     //	Define body relation map.
     //	The contact map gives the topological connections between the bodies.
@@ -257,7 +257,7 @@ int main(int ac, char *av[])
     InnerRelation cylinder_inner(cylinder);
     ComplexRelation water_block_complex(water_block_inner, {&wall_boundary, &cylinder});
     ContactRelation cylinder_contact(cylinder, {&water_block});
-    ContactRelation fluid_observer_contact(fluid_observer, {&cylinder});
+    ContactRelation cylinder_observer_contact(cylinder_observer, {&cylinder});
     //----------------------------------------------------------------------
     //	Run particle relaxation for body-fitted distribution if chosen.
     //----------------------------------------------------------------------
@@ -309,7 +309,7 @@ int main(int ac, char *av[])
     SimpleDynamics<TimeStepInitialization> fluid_step_initialization(water_block, gravity_ptr);
     InteractionWithUpdate<fluid_dynamics::WettingCoupledSpatialTemporalFreeSurfaceIdentificationComplex>
         free_stream_surface_indicator(water_block_complex);
-    InteractionWithUpdate<fluid_dynamics::DensitySummationFreeStreamComplex> fluid_density_by_summation(water_block_complex);
+    InteractionWithUpdate<fluid_dynamics::DensitySummationFreeSurfaceComplex> fluid_density_by_summation(water_block_complex);
     water_block.addBodyStateForRecording<Real>("Pressure");
     water_block.addBodyStateForRecording<Real>("Density");
     water_block.addBodyStateForRecording<int>("Indicator");
@@ -384,7 +384,7 @@ int main(int ac, char *av[])
     BodyStatesRecordingToVtp body_states_recording(io_environment, sph_system.real_bodies_);
     RestartIO restart_io(io_environment, sph_system.real_bodies_);
     RegressionTestDynamicTimeWarping<ObservedQuantityRecording<Vecd>>
-        write_cylinder_displacement("Position", io_environment, fluid_observer_contact);
+        write_cylinder_displacement("Position", io_environment, cylinder_observer_contact);
     //----------------------------------------------------------------------
     //	Prepare the simulation with cell linked list, configuration
     //	and case specified initial condition if necessary.
@@ -406,7 +406,6 @@ int main(int ac, char *av[])
         GlobalStaticVariables::physical_time_ = restart_io.readRestartFiles(sph_system.RestartStep());
         water_block.updateCellLinkedList();
         water_block_complex.updateConfiguration();
-        fluid_observer_contact.updateConfiguration();
         cylinder.updateCellLinkedList();
         water_block_inner.updateConfiguration();
         cylinder_inner.updateConfiguration();
@@ -419,7 +418,7 @@ int main(int ac, char *av[])
     int screen_output_interval = 100;
     int observation_sample_interval = screen_output_interval * 2;
     int restart_output_interval = screen_output_interval * 10;
-    Real end_time = 0.7;
+    Real end_time = 1.0;
     Real output_interval = end_time / 70.0;
     //----------------------------------------------------------------------
     //	Statistics for CPU time
@@ -503,7 +502,6 @@ int main(int ac, char *av[])
             cylinder_inner.updateConfiguration();
             cylinder_contact.updateConfiguration();
             water_block_complex.updateConfiguration();
-            fluid_observer_contact.updateConfiguration();
             free_stream_surface_indicator.exec();
             interval_updating_configuration += TickCount::now() - time_instance;
         }
@@ -535,6 +533,5 @@ int main(int ac, char *av[])
         write_cylinder_displacement.testResult();
     }
 
-
     return 0;
 };
diff --git a/tests/user_examples/test_3d_repose_angle/CMakeLists.txt b/tests/user_examples/test_3d_repose_angle/CMakeLists.txt
index 79ed1a178e..81b352c2e4 100644
--- a/tests/user_examples/test_3d_repose_angle/CMakeLists.txt
+++ b/tests/user_examples/test_3d_repose_angle/CMakeLists.txt
@@ -16,7 +16,7 @@ target_sources(${PROJECT_NAME} PRIVATE ${DIR_SRCS})
 target_link_libraries(${PROJECT_NAME} extra_sources_3d)
 set_target_properties(${PROJECT_NAME} PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${EXECUTABLE_OUTPUT_PATH}")
 
-add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --r=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME}_particle_relaxation COMMAND ${PROJECT_NAME} --relax=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME} --r=false --i=true --state_recording=${TEST_STATE_RECORDING}
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME}  --reload=true --state_recording=${TEST_STATE_RECORDING}
         WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH})
diff --git a/tests/user_examples/xj_stretching/run_test.sh b/tests/user_examples/xj_stretching/run_test.sh
deleted file mode 100644
index 8aaa13ab55..0000000000
--- a/tests/user_examples/xj_stretching/run_test.sh
+++ /dev/null
@@ -1,2 +0,0 @@
-./xj_stretching --r=true
-./xj_stretching --r=false --i=true
diff --git a/tests/user_examples/xj_stretching/xj_stretching.cpp b/tests/user_examples/xj_stretching/xj_stretching.cpp
deleted file mode 100644
index 7233b7e595..0000000000
--- a/tests/user_examples/xj_stretching/xj_stretching.cpp
+++ /dev/null
@@ -1,373 +0,0 @@
-/* ---------------------------------------------------------------------------*
-*            SPHinXsys: 2D oscillation beam example-one body version           *
-* ----------------------------------------------------------------------------*
-* This is the one of the basic test cases, also the first case for            *
-* understanding SPH method for solid simulation.                              *
-* In this case, the constraint of the beam is implemented with                *
-* internal constrained subregion.                                             *
-* ----------------------------------------------------------------------------*/
-#include "sphinxsys.h"
-#include "inelastic_solid_hardening.h"
-
-using namespace SPH;
-//------------------------------------------------------------------------------
-//global parameters for the case
-//------------------------------------------------------------------------------
-Real PL = 0.05334;	//beam length
-Real PH = 0.012826; //for thick plate; 
-
-//reference particle spacing
-Real resolution_ref = PH / 30;
-Real BW  = resolution_ref * 4.0 ; //boundary width, at least three particles
-
-/** Domain bounds of the system. */
-BoundingBox system_domain_bounds(Vec2d(-PL / 2.0, -PL / 2.0),
-								 Vec2d(2.0*PL , PL / 2.0));
-// two dimensional should be circle smooth between two parts.
-//----------------------------------------------------------------------
-Real rho0_s = 7850.0; /**< Reference density. */
-Real Shear_modulus = 80.1938e9;  /**< Poisson ratio. */
-Real Bulk_modulus = 164.21e9;
-
-Real poisson = (3.0 * Bulk_modulus -2.0 * Shear_modulus)/(6.0 * Bulk_modulus + 2.0 * Shear_modulus);  /**< Poisson ratio. */
-Real Youngs_modulus = (9.0 * Shear_modulus * Bulk_modulus)/(3.0* Bulk_modulus + Shear_modulus);
-
-
-Real yield_stress = 0.45e9;
-Real hardening_modulus = 1.2924e8;
-Real saturation_flow_stress = 7.15e8;
-Real saturation_exponent = 16.93;
-
-Real physical_viscosity = 1.0e4; 
-Real refer_energy = 0.5*8000*0.01; //40
-
-Vecd norm_(1.0, 0.0);
-Vecd upper_face_point_(0.02 + 3.0 * resolution_ref, 0.0);
-Vecd lower_face_point_(0.02, 0.0);
-
-
-Vecd norm_4(1.0, 0.0);
-Vecd upper_face_point_4(0.04 + 3.0 * resolution_ref, 0.0);
-Vecd lower_face_point_4(0.04, 0.0);
-
-//Beam observer location
-StdVec<Vecd> observation_location = { Vecd( PL / 2.0 ,  PH / 2.0 - PH * 0.01) };
-
-//----------------------------------------------------------------------
-//	Geometric shapes used in the system.
-//----------------------------------------------------------------------
-
-std::vector<Vecd> beam_left_stretch_shape{
-	Vecd(-BW , -PH / 2 ), Vecd(-BW, PH / 2 ), Vecd(0.0, PH / 2 ),
-	Vecd(0.0, -PH / 2 ), Vecd(-BW, -PH / 2 )};
-
-//a beam shape
-std::vector<Vecd> beam_shape{
-	Vecd(0.0, -PH / 2), Vecd(0.0, PH / 2), 
-	Vecd(PL / 2.0 , PH / 2 - PH * 0.01),
-	Vecd(PL, PH / 2), Vecd(PL , -PH / 2), 
-	Vecd(PL / 2.0 , -PH / 2 + PH * 0.01),
-	Vecd(0.0, -PH / 2) };
-
-std::vector<Vecd> beam_right_stretch_shape{
-	Vecd(PL, -PH / 2 ), Vecd(PL, PH / 2 ), Vecd(PL +BW , PH / 2 ),
-	Vecd(PL+BW, -PH / 2 ), Vecd(PL, -PH / 2 ) };
-
-//----------------------------------------------------------------------
-//	Define the beam body
-//----------------------------------------------------------------------
-class Beam : public MultiPolygonShape
-{
-public:
-	explicit Beam(const std::string &shape_name) : MultiPolygonShape(shape_name)
-	{
-		multi_polygon_.addAPolygon(beam_right_stretch_shape, ShapeBooleanOps::add);
-	    multi_polygon_.addAPolygon(beam_shape, ShapeBooleanOps::add);
-		multi_polygon_.addAPolygon(beam_left_stretch_shape, ShapeBooleanOps::add);
-
-	}
-};
-
-class LeftStretchSolidBodyRegion : public solid_dynamics::BaseMotionConstraint<BodyPartByParticle>
-{
-public:
-	// TODO: use only body part as argment since body can be referred from it already
-	LeftStretchSolidBodyRegion(BodyPartByParticle &body_part)
-		:solid_dynamics::BaseMotionConstraint<BodyPartByParticle>(body_part),
-		vel_(particles_->vel_), pos_(particles_->pos_){};
-
-	virtual ~LeftStretchSolidBodyRegion() {};
-protected:
-	StdLargeVec<Vecd> &vel_;
-	StdLargeVec<Vecd> &pos_;
-	virtual void update(size_t index_i, Real Dt = 0.0)
-	{
-		pos_[index_i][0] -= 0.5e-4 * Dt;	
-	};
-};
-
-class RightStretchSolidBodyRegion : public solid_dynamics::BaseMotionConstraint<BodyPartByParticle>
-{
-public:
-	// TODO: use only body part as argment since body can be referred from it already
-	RightStretchSolidBodyRegion(BodyPartByParticle &body_part)
-		:solid_dynamics::BaseMotionConstraint<BodyPartByParticle>(body_part),
-		vel_(particles_->vel_), pos_(particles_->pos_){};
-
-	virtual ~RightStretchSolidBodyRegion() {};
-
-protected:
-	StdLargeVec<Vecd> &vel_;
-	StdLargeVec<Vecd> &pos_;
-	virtual void update(size_t index_i, Real Dt = 0.0)
-	{
-	  pos_[index_i][0] += 0.5e-4 * Dt;
-	};
-};
-
-MultiPolygon createBeamRightStretchShape()
-{
-	MultiPolygon multi_polygon;
-	multi_polygon.addAPolygon(beam_right_stretch_shape, ShapeBooleanOps::add);
-	return multi_polygon;
-};
-
-MultiPolygon createBeamLeftStretchShape()
-{
-	MultiPolygon multi_polygon;
-	multi_polygon.addAPolygon(beam_left_stretch_shape, ShapeBooleanOps::add);
-	return multi_polygon;
-};
-
-
-MultiPolygon createConstrainBeamShape()
-{
-	MultiPolygon multi_polygon;
-	multi_polygon.addAPolygon(beam_left_stretch_shape, ShapeBooleanOps::add);
-	multi_polygon.addAPolygon(beam_right_stretch_shape, ShapeBooleanOps::add);
-	
-	return multi_polygon;
-};
-
-class ConstrainXVelocity : public solid_dynamics::BaseMotionConstraint<BodyPartByParticle>
-{
-public:
-	// TODO: use only body part as argment since body can be referred from it already
-	ConstrainXVelocity(BodyPartByParticle &body_part)
-	    :solid_dynamics::BaseMotionConstraint<BodyPartByParticle>(body_part),
-		vel_(particles_->vel_), pos_(particles_->pos_){};
-
-	virtual ~ConstrainXVelocity() {};
-protected:
-	StdLargeVec<Vecd> &vel_;
-	StdLargeVec<Vecd> &pos_;
-	virtual void update(size_t index_i, Real dt = 0.0)
-	{
-		vel_[index_i] = Vecd(0.0, vel_[index_i][1]);
-	};
-};
-
-//------------------------------------------------------------------------------
-//the main program
-//------------------------------------------------------------------------------
-int main(int ac, char *av[])
-{
-	//----------------------------------------------------------------------
-	//	Build up the environment of a SPHSystem with global controls.
-	//----------------------------------------------------------------------
-	SPHSystem system(system_domain_bounds, resolution_ref);
-	/** Tag for running particle relaxation for the initially body-fitted distribution */
-    system.setRunParticleRelaxation(false);
-    /** Tag for starting with relaxed body-fitted particles distribution */
-    system.setReloadParticles(true);
-	system.handleCommandlineOptions(ac, av);
-    IOEnvironment io_environment(system);
-
-	//----------------------------------------------------------------------
-	//	Creating body, materials and particles.
-	//----------------------------------------------------------------------
-	SolidBody beam_body(system, makeShared<Beam>("StretchingBody"));
-	beam_body.defineBodyLevelSetShape();
-	beam_body.defineParticlesAndMaterial<ElasticSolidParticles, NonLinearHardeningPlasticSolid>(
-		rho0_s, Youngs_modulus, poisson, yield_stress, hardening_modulus, saturation_flow_stress, saturation_exponent);
-	
-	(!system.RunParticleRelaxation() && system.ReloadParticles())
-		? beam_body.generateParticles<ParticleGeneratorReload>(io_environment, beam_body.getName())
-		: beam_body.generateParticles<ParticleGeneratorLattice>();
-
-
-	ObserverBody beam_observer(system, "BeamObserver");
-	beam_observer.generateParticles<ObserverParticleGenerator>(observation_location);
-	//----------------------------------------------------------------------
-	//	Define body relation map.
-	//	The contact map gives the topological connections between the bodies.
-	//	Basically the the range of bodies to build neighbor particle lists.
-	//----------------------------------------------------------------------
-	if (system.RunParticleRelaxation())
-	{
-		//----------------------------------------------------------------------
-		//	Define body relation map used for particle relaxation.
-		//----------------------------------------------------------------------
-		InnerRelation beam_body_inner(beam_body);
-		//----------------------------------------------------------------------
-		//	Define the methods for particle relaxation.
-		//----------------------------------------------------------------------
-		SimpleDynamics<RandomizeParticlePosition>   beam_body_random_particles(beam_body);
-		relax_dynamics::RelaxationStepInner beam_body_relaxation_step_inner(beam_body_inner);
-		//----------------------------------------------------------------------
-		//	Output for particle relaxation.
-		//----------------------------------------------------------------------
-		BodyStatesRecordingToVtp write_ball_state(io_environment, system.real_bodies_);
-		ReloadParticleIO write_particle_reload_files(io_environment, { &beam_body });
-		//----------------------------------------------------------------------
-		//	Particle relaxation starts here.
-		//----------------------------------------------------------------------
-		beam_body_random_particles.exec(0.25);
-		write_ball_state.writeToFile(0);
-		//----------------------------------------------------------------------
-		//	From here iteration for particle relaxation begins.
-		//----------------------------------------------------------------------
-		int ite = 0;
-		int relax_step = 1000;
-		while (ite < relax_step)
-		{
-			beam_body_relaxation_step_inner.exec();
-			ite += 1;
-			if (ite % 100 == 0)
-			{
-				std::cout << std::fixed << std::setprecision(9) << "Relaxation steps N = " << ite << "\n";
-				write_ball_state.writeToFile(ite);
-			}
-		}
-		std::cout << "The physics relaxation process of particles finish !" << std::endl;
-		write_particle_reload_files.writeToFile(0);
-		return 0;
-	}
-
-	InnerRelation beam_body_inner(beam_body);
-	ContactRelation beam_observer_contact(beam_observer, {&beam_body});
-	//-----------------------------------------------------------------------------
-	//this section define all numerical methods will be used in this case
-	//-----------------------------------------------------------------------------
-
-	//corrected strong configuration
-	InteractionWithUpdate<CorrectedConfigurationInner> beam_corrected_configuration(beam_body_inner);
-
-	//time step size calculation
- 	ReduceDynamics<solid_dynamics::AcousticTimeStepSize> computing_time_step_size(beam_body);
-	//stress relaxation for the beam
-	Dynamics1Level<solid_dynamics::PlasticIntegration1stHalf> stress_relaxation_first_half(beam_body_inner);
-	Dynamics1Level<solid_dynamics::Integration2ndHalf> stress_relaxation_second_half(beam_body_inner); 
-	ReduceDynamics<TotalMechanicalEnergy> get_kinetic_energy(beam_body);
-         
-	BodyRegionByParticle beam_left_stretch(beam_body, makeShared<MultiPolygonShape>(createBeamLeftStretchShape()));
-	SimpleDynamics<LeftStretchSolidBodyRegion> stretch_beam_left_end(beam_left_stretch);
-	BodyRegionByParticle beam_right_stretch(beam_body, makeShared<MultiPolygonShape>(createBeamRightStretchShape()));
-	SimpleDynamics<RightStretchSolidBodyRegion> stretch_beam_right_end(beam_right_stretch);
-	BodyRegionByParticle beam_constrain(beam_body, makeShared<MultiPolygonShape>(createConstrainBeamShape()));
-	SimpleDynamics<ConstrainXVelocity> constrain_beam_end(beam_constrain);
-
-	InteractionDynamics<solid_dynamics::DeformationGradientBySummation> beam_deformation_gradient_tensor(beam_body_inner);
-	DampingWithRandomChoice<InteractionSplit<DampingPairwiseInner<Vec2d>>>
-        damping(0.5, beam_body_inner, "Velocity", physical_viscosity);
-
-	//-----------------------------------------------------------------------------
-	//outputs
-	//-----------------------------------------------------------------------------
-
-   BodyStatesRecordingToVtp write_beam_states(io_environment, system.real_bodies_);
-   ReducedQuantityRecording<ReduceDynamics<TotalMechanicalEnergy>>
-		write_total_mechanical_energy(io_environment, beam_body);
-	//----------------------------------------------------------------------
-	//	Setup computing and initial conditions.
-	//----------------------------------------------------------------------
-	system.initializeSystemCellLinkedLists();
-	system.initializeSystemConfigurations();
-	beam_corrected_configuration.exec();
-
-	//----------------------------------------------------------------------
-	//	Setup computing time-step controls.
-	//----------------------------------------------------------------------
-	int ite = 0;
-	int Dt_ite = 0;
-	Real End_Time = 100.0;
-	
-	Real D_Time = End_Time /100.0;//time step size for output file
-	Real Dt = End_Time /10000.0;  /**< Time period for stretching */
-	Real dt = 0.0;			//default acoustic time step sizes
-
-	// statistics for computing time
-    TickCount t1 = TickCount::now();
-    TimeInterval interval;
-	//-----------------------------------------------------------------------------
-	//from here the time stepping begines
-	//-----------------------------------------------------------------------------
-	write_beam_states.writeToFile(0);
-	write_total_mechanical_energy.writeToFile(0);
-
-	//computation loop starts
-	while (GlobalStaticVariables::physical_time_ < End_Time)
-	{
-		Real integration_time = 0.0;
-		//integrate time (loop) until the next output time
-		while (integration_time < D_Time)
-		{
-			Real relaxation_time = 0.0;
-			stretch_beam_left_end.exec(Dt);
-			stretch_beam_right_end.exec(Dt);
-			beam_deformation_gradient_tensor.exec(Dt);
-		    Dt_ite ++;
-
-			int stress_ite = 0;
-			Real refer_total_kinetic_energy = 10000.0;
-			while (relaxation_time < Dt)
-			{
-				if (refer_total_kinetic_energy > 0.005)
-				{
-					stress_relaxation_first_half.exec(dt);
-					constrain_beam_end.exec(dt);
-					damping.exec(Dt);
-					constrain_beam_end.exec(dt);
-					stress_relaxation_second_half.exec(dt);
-
-					refer_total_kinetic_energy = get_kinetic_energy.exec() / refer_energy;
-
-					ite++;
-					stress_ite++;
-
-					dt = computing_time_step_size.exec();
-					if (ite % 500 == 0)
-					{
-						std::cout << "N=" << ite << " Time: "
-							<< GlobalStaticVariables::physical_time_
-							<< "	Dt: " << Dt << "	dt: " << dt
-							<< "	Dt:dt = " << Dt / dt <<
-							"\n";
-					}
-				}
-				relaxation_time += dt;
-				integration_time += dt;
-				GlobalStaticVariables::physical_time_ += dt;
-			}
-            
-			
-			std::cout << "refer_total_kinetic_energy  " << refer_total_kinetic_energy
-			 <<  "    stress_ite  " << stress_ite <<std::endl;
-		
-		}
-
-	    TickCount t2 = TickCount::now();
-        write_beam_states.writeToFile();
-        TickCount t3 = TickCount::now();
-        interval += t3 - t2;
-	}
-	TickCount t4 = TickCount::now();
-
-    TimeInterval tt;
-    tt = t4 - t1 - interval;
-	std::cout << "Total wall time for computation: " << tt.seconds() << " seconds." 
-	<< "  Iterations:  " << ite << std::endl;
-   std::cout << "Total iterations computation:  " << GlobalStaticVariables::physical_time_/dt 
-		<< std::endl;
-	return 0;
-}