FEM: elmer unit tests, add SI units file writing test

src/Mod/Fem/CMakeLists.txt

@@ -265,6 +265,7 @@ SET(FemTestsElmer_SRCS
     femtest/data/elmer/__init__.py
     femtest/data/elmer/box_static_mm.sif
     femtest/data/elmer/ccxcantilever_faceload_mm.sif
+    femtest/data/elmer/ccxcantilever_faceload_1_si.sif
     femtest/data/elmer/ccxcantilever_nodeload_mm.sif
     femtest/data/elmer/ccxcantilever_prescribeddisplacement_mm.sif
     femtest/data/elmer/group_mesh.geo

src/Mod/Fem/femtest/app/test_solver_elmer.py

@@ -56,23 +56,24 @@ def setUp(
             testtools.get_fem_test_home_dir(),
             "elmer"
         )
-
-        # make sure std FreeCAD unit system mm/kg/s is used
+        # set Units
+        # since in Elmer writer the FreeCAD pref is used, here we need to set the FreeCAD pref
+        # the use of FreeCAD.Units.setScheme would not take affect because the pref is not changed
+        # see https://forum.freecadweb.org/viewtopic.php?t=48451
         param = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Units")
-        self.unit_schema = param.GetInt("UserSchema")
-        if self.unit_schema != 0:
-            fcc_print("Unit schema: {}. Set unit schema to 0 (mm/kg/s)".format(self.unit_schema))
-            param.SetInt("UserSchema", 0)
+        self.saved_unit_schema = param.GetInt("UserSchema")
 
     # ********************************************************************************************
     def tearDown(
         self
     ):
         # set back unit unit schema
-        if self.unit_schema != 0:
-            fcc_print("Set unit schema back to {}".format(self.unit_schema))
+        param = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Units")
+        unit_schema = param.GetInt("UserSchema")
+        if unit_schema != self.saved_unit_schema:
+            fcc_print("Reset unit schema back to {}".format(self.saved_unit_schema))
             param = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Units")
-            param.SetInt("UserSchema", self.unit_schema)
+            param.SetInt("UserSchema", self.saved_unit_schema)
 
         # tearDown is executed after every test
         FreeCAD.closeDocument(self.document.Name)
@@ -92,10 +93,23 @@ def test_00print(
         ))
 
     # ********************************************************************************************
-    def test_box_static(
+    def set_unit_schema(
+        self,
+        new_unit_schema=0
+    ):
+        fcc_print(
+            "\nSaved unit schema: {}. Set unit schema to {}."
+            .format(self.saved_unit_schema, new_unit_schema)
+        )
+        param = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Units")
+        param.SetInt("UserSchema", new_unit_schema)
+
+    # ********************************************************************************************
+    def test_box_static_mm(
         self
     ):
         fcc_print("")
+        self.set_unit_schema(0)  # mm/kg/s
 
         # set up the Elmer static analysis example
         from femexamples.boxanalysis_static import setup
@@ -133,7 +147,7 @@ def test_box_static(
         self.assertFalse(ret, "STARTINFO write file test failed.\n{}".format(ret))
 
         fcc_print("Test writing case file")
-        casefile_given = join(self.test_file_dir, base_name + "_mm" + self.ending)
+        casefile_given = join(self.test_file_dir, base_name + self.ending)
         casefile_totest = join(analysis_dir, self.infilename + self.ending)
         # fcc_print("Comparing {} to {}".format(casefile_given, casefile_totest))
         ret = testtools.compare_files(casefile_given, casefile_totest)
@@ -147,28 +161,41 @@ def test_box_static(
         self.assertFalse(ret, "GMSH geo write file test failed.\n{}".format(ret))
 
     # ********************************************************************************************
-    def test_ccxcantilever_faceload(
+    def test_ccxcantilever_faceload_mm(
+        self
+    ):
+        fcc_print("")
+        self.set_unit_schema(0)  # mm/kg/s
+        from femexamples.ccx_cantilever_faceload import setup
+        setup(self.document, "elmer")
+        self.input_file_writing_test(get_namefromdef("test_"))
+
+    # ********************************************************************************************
+    def test_ccxcantilever_faceload_1_si(
         self
     ):
         fcc_print("")
+        self.set_unit_schema(1)  # SI-units m/kg/s
         from femexamples.ccx_cantilever_faceload import setup
         setup(self.document, "elmer")
         self.input_file_writing_test(get_namefromdef("test_"))
 
     # ********************************************************************************************
-    def test_ccxcantilever_nodeload(
+    def test_ccxcantilever_nodeload_mm(
         self
     ):
         fcc_print("")
+        self.set_unit_schema(0)  # mm/kg/s
         from femexamples.ccx_cantilever_nodeload import setup
         setup(self.document, "elmer")
         self.input_file_writing_test(get_namefromdef("test_"))
 
     # ********************************************************************************************
-    def test_ccxcantilever_prescribeddisplacement(
+    def test_ccxcantilever_prescribeddisplacement_mm(
         self
     ):
         fcc_print("")
+        self.set_unit_schema(0)  # mm/kg/s
         from femexamples.ccx_cantilever_prescribeddisplacement import setup
         setup(self.document, "elmer")
         self.input_file_writing_test(get_namefromdef("test_"))
@@ -199,7 +226,7 @@ def input_file_writing_test(
         # compare input file with the given one
         inpfile_given = join(
             self.test_file_dir,
-            base_name + "_mm" + self.ending
+            base_name + self.ending
         )
         inpfile_totest = join(
             working_dir,

src/Mod/Fem/femtest/data/elmer/ccxcantilever_faceload_1_si.sif

@@ -0,0 +1,90 @@
+Check Keywords Warn
+
+Header
+  Mesh DB "."
+End
+
+Solver 1
+  Bubbles = Logical False
+  Calculate Pangle = Logical False
+  Calculate Principal = Logical False
+  Calculate Strains = Logical False
+  Calculate Stresses = Logical False
+  Displace mesh = Logical False
+  Eigen Analysis = Logical False
+  Eigen System Values = Integer 5
+  Equation = String "Elasticity"
+  Exec Solver = String "Always"
+  Linear System Abort Not Converged = Logical False
+  Linear System Convergence Tolerance = Real 1e-08
+  Linear System Iterative Method = String "BiCGStab"
+  Linear System Max Iterations = Integer 500
+  Linear System Precondition Recompute = Integer 1
+  Linear System Preconditioning = String "ILU0"
+  Linear System Residual Output = Integer 1
+  Linear System Solver = String "Iterative"
+  Optimize Bandwidth = Logical True
+  Procedure = File "StressSolve" "StressSolver"
+  Stabilize = Logical True
+  Steady State Convergence Tolerance = Real 1e-05
+  Variable = String "Displacement"
+  Variable DOFs = Integer 3
+End
+
+Simulation 
+  BDF Order = Integer 1
+  Coordinate Mapping(3) = Integer 1 2 3
+  Coordinate Scaling = Real 0.001
+  Coordinate System = String "Cartesian 3D"
+  Output Intervals = Integer 1
+  Simulation Type = String "Steady state"
+  Steady State Max Iterations = Integer 1
+  Steady State Min Iterations = Integer 0
+  Timestepping Method = String "BDF"
+  Use Mesh Names = Logical True
+End
+
+Constants 
+End
+
+Body 1
+  Equation = Integer 1
+  Material = Integer 1
+  Name = String "Solid1"
+End
+
+Material 1
+  Poisson ratio = Real 0.3
+  Youngs Modulus = Real 210000000000.0
+End
+
+Equation 1
+  Active Solvers(2) = Integer 1 2
+End
+
+Solver 2
+  Coordinate Scaling Revert = Logical True
+  Equation = String "ResultOutput"
+  Exec Solver = String "After simulation"
+  Output File Name = File "case"
+  Procedure = File "ResultOutputSolve" "ResultOutputSolver"
+  Vtu Format = Logical True
+End
+
+Boundary Condition 1
+  Displacement 1 = Real 0.0
+  Displacement 2 = Real 0.0
+  Displacement 3 = Real 0.0
+  Name = String "Face1"
+End
+
+Boundary Condition 2
+  Force 1 = Real -0.0
+  Force 1 Normalize by Area = Logical True
+  Force 2 = Real -0.0
+  Force 2 Normalize by Area = Logical True
+  Force 3 = Real -9000000.0
+  Force 3 Normalize by Area = Logical True
+  Name = String "Face2"
+End
+