FEM: examples, add simple calculix frequency example

src/Mod/Fem/CMakeLists.txt

@@ -58,6 +58,7 @@ SET(FemExamples_SRCS
     femexamples/elmer_nonguitutorial01_eigenvalue_of_elastic_beam.py
     femexamples/equation_electrostatics_capacitance_two_balls.py
     femexamples/equation_electrostatics_electricforce_elmer_nongui6.py
+    femexamples/frequency_beamsimple.py
     femexamples/manager.py
     femexamples/material_multiple_bendingbeam_fiveboxes.py
     femexamples/material_multiple_bendingbeam_fivefaces.py
@@ -73,6 +74,7 @@ SET(FemExamples_SRCS
 
 SET(FemExampleMeshes_SRCS
     femexamples/meshes/__init__.py
+    femexamples/meshes/mesh_beamsimple_tetra10.py
     femexamples/meshes/mesh_boxanalysis_tetra10.py
     femexamples/meshes/mesh_boxes_2_vertikal_tetra10.py
     femexamples/meshes/mesh_canticcx_hexa20.py

src/Mod/Fem/femexamples/frequency_beamsimple.py

@@ -0,0 +1,163 @@
+# ***************************************************************************
+# *   Copyright (c) 2021 Bernd Hahnebach <bernd@bimstatik.org>              *
+# *                                                                         *
+# *   This file is part of the FreeCAD CAx development system.              *
+# *                                                                         *
+# *   This program is free software; you can redistribute it and/or modify  *
+# *   it under the terms of the GNU Lesser General Public License (LGPL)    *
+# *   as published by the Free Software Foundation; either version 2 of     *
+# *   the License, or (at your option) any later version.                   *
+# *   for detail see the LICENCE text file.                                 *
+# *                                                                         *
+# *   This program is distributed in the hope that it will be useful,       *
+# *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+# *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+# *   GNU Library General Public License for more details.                  *
+# *                                                                         *
+# *   You should have received a copy of the GNU Library General Public     *
+# *   License along with this program; if not, write to the Free Software   *
+# *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
+# *   USA                                                                   *
+# *                                                                         *
+# ***************************************************************************
+
+# to run the example use:
+"""
+from femexamples.frequency_beamsimple import setup
+setup()
+
+"""
+# simple frequency analysis
+# https://forum.freecadweb.org/viewtopic.php?f=18&t=58959#p506565
+
+import FreeCAD
+
+import Fem
+import ObjectsFem
+
+mesh_name = "Mesh"  # needs to be Mesh to work with unit tests
+
+
+def init_doc(doc=None):
+    if doc is None:
+        doc = FreeCAD.newDocument()
+    return doc
+
+
+def get_information():
+    info = {"name": "Frequency Analysis Simple Beam",
+            "meshtype": "solid",
+            "meshelement": "Tet10",
+            "constraints": ["fixed"],
+            "solvers": ["calculix"],
+            "material": "solid",
+            "equation": "frequency"
+            }
+    return info
+
+
+def setup(doc=None, solvertype="ccxtools"):
+    # setup simple beam frequency
+
+    if doc is None:
+        doc = init_doc()
+
+    # geometry object
+    geom_obj = doc.addObject("Part::Box", "Box")
+    geom_obj.Length = 3000
+    geom_obj.Width = 100
+    geom_obj.Height = 50
+    doc.recompute()
+
+    if FreeCAD.GuiUp:
+        geom_obj.ViewObject.Document.activeView().viewAxonometric()
+        geom_obj.ViewObject.Document.activeView().fitAll()
+
+    # analysis
+    analysis = ObjectsFem.makeAnalysis(doc, "Analysis")
+
+    # solver
+    if solvertype == "calculix":
+        solver_object = analysis.addObject(
+            ObjectsFem.makeSolverCalculix(doc, "SolverCalculiX")
+        )[0]
+    elif solvertype == "ccxtools":
+        solver_object = analysis.addObject(
+            ObjectsFem.makeSolverCalculixCcxTools(doc, "CalculiXccxTools")
+        )[0]
+        solver_object.WorkingDir = u""
+    else:
+        FreeCAD.Console.PrintWarning(
+            "Not known or not supported solver type: {}. "
+            "No solver object was created.\n".format(solvertype)
+        )
+    if solvertype == "calculix" or solvertype == "ccxtools":
+        solver_object.SplitInputWriter = False
+        solver_object.AnalysisType = "frequency"
+        solver_object.GeometricalNonlinearity = "linear"
+        solver_object.ThermoMechSteadyState = False
+        solver_object.MatrixSolverType = "default"
+        solver_object.IterationsControlParameterTimeUse = False
+        solver_object.EigenmodesCount = 10
+        solver_object.EigenmodeHighLimit = 1000000.0
+        solver_object.EigenmodeLowLimit = 0.01
+
+    # material
+    material_object = analysis.addObject(
+        ObjectsFem.makeMaterialSolid(doc, "MechanicalMaterial")
+    )[0]
+    mat = material_object.Material
+    mat["Name"] = "Steel-Generic"
+    mat["YoungsModulus"] = "200000 MPa"
+    mat["PoissonRatio"] = "0.30"
+    mat["Density"] = "7900 kg/m^3"
+    material_object.Material = mat
+
+    # displacement_constraint 1
+    displacement_constraint = doc.Analysis.addObject(
+        ObjectsFem.makeConstraintDisplacement(doc, name="Fix_XYZ")
+    )[0]
+    displacement_constraint.References = [(doc.Box, "Edge4")]
+    displacement_constraint.xFix = True
+    displacement_constraint.xFree = False
+    displacement_constraint.xDisplacement = 0.0
+    displacement_constraint.yFix = True
+    displacement_constraint.yFree = False
+    displacement_constraint.yDisplacement = 0.0
+    displacement_constraint.zFix = True
+    displacement_constraint.zFree = False
+    displacement_constraint.zDisplacement = 0.0
+
+    # displacement_constraint 2
+    displacement_constraint = doc.Analysis.addObject(
+        ObjectsFem.makeConstraintDisplacement(doc, name="Fix_YZ")
+    )[0]
+    displacement_constraint.References = [(doc.Box, "Edge8")]
+    displacement_constraint.xFix = False
+    displacement_constraint.xFree = True
+    displacement_constraint.xDisplacement = 0.0
+    displacement_constraint.yFix = True
+    displacement_constraint.yFree = False
+    displacement_constraint.yDisplacement = 0.0
+    displacement_constraint.zFix = True
+    displacement_constraint.zFree = False
+    displacement_constraint.zDisplacement = 0.0
+
+    # mesh
+    from .meshes.mesh_beamsimple_tetra10 import create_nodes, create_elements
+
+    fem_mesh = Fem.FemMesh()
+    control = create_nodes(fem_mesh)
+    if not control:
+        FreeCAD.Console.PrintError("Error on creating nodes.\n")
+    control = create_elements(fem_mesh)
+    if not control:
+        FreeCAD.Console.PrintError("Error on creating elements.\n")
+    femmesh_obj = analysis.addObject(ObjectsFem.makeMeshGmsh(doc, mesh_name))[0]
+    femmesh_obj.FemMesh = fem_mesh
+    femmesh_obj.Part = geom_obj
+    femmesh_obj.SecondOrderLinear = False
+    femmesh_obj.CharacteristicLengthMax = "25.0 mm"
+
+    doc.recompute()
+    return doc