FEM: CalxuliX cantlever beam examples for pipe, circle and rectangle …

…cross section
FreeCAD · Aug 3, 2021 · f7cefae · f7cefae
1 parent ea9272b
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diff --git a/src/Mod/Fem/CMakeLists.txt b/src/Mod/Fem/CMakeLists.txt
@@ -51,6 +51,9 @@ SET(FemExamples_SRCS
     femexamples/ccx_cantilever_base_edge.py
     femexamples/ccx_cantilever_base_face.py
     femexamples/ccx_cantilever_base_solid.py
+    femexamples/ccx_cantilever_beam_circle.py
+    femexamples/ccx_cantilever_beam_pipe.py
+    femexamples/ccx_cantilever_beam_rect.py
     femexamples/ccx_cantilever_ele_hexa20.py
     femexamples/ccx_cantilever_ele_quad4.py
     femexamples/ccx_cantilever_ele_quad8.py

diff --git a/src/Mod/Fem/femexamples/ccx_cantilever_base_edge.py b/src/Mod/Fem/femexamples/ccx_cantilever_base_edge.py
@@ -59,6 +59,7 @@ def setup_cantilever_base_edge(doc=None, solvertype="ccxtools"):
     doc.recompute()
 
     if FreeCAD.GuiUp:
+        load_line.ViewObject.Visibility = False
         geom_obj.ViewObject.Document.activeView().viewAxonometric()
         geom_obj.ViewObject.Document.activeView().fitAll()
 

diff --git a/src/Mod/Fem/femexamples/ccx_cantilever_beam_circle.py b/src/Mod/Fem/femexamples/ccx_cantilever_beam_circle.py
@@ -0,0 +1,110 @@
+# ***************************************************************************
+# *   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                                                                   *
+# *                                                                         *
+# ***************************************************************************
+
+import FreeCAD
+
+from . import manager
+from .ccx_cantilever_base_edge import setup_cantilever_base_edge
+from .manager import init_doc
+
+
+def get_information():
+    return {
+        "name": "CCX cantilever beam circle",
+        "meshtype": "edge",
+        "meshelement": "Seg3",
+        "constraints": ["fixed", "force"],
+        "solvers": ["calculix"],
+        "material": "solid",
+        "equation": "mechanical"
+    }
+
+
+def get_explanation(header=""):
+    return header + """
+
+To run the example from Python console use:
+from femexamples.ccx_cantilever_beam_circle import setup
+setup()
+
+
+See forum topic post:
+https://forum.freecadweb.org/viewtopic.php?f=18&t=16044
+
+CalculiX cantilever:
+- modeled with seg3 beam elements
+
+CrossSection:
+- circle
+- diameter 1000 mm
+
+max deflection:
+doc = App.ActiveDocument
+len = doc.CantileverLine.Shape.Length
+iyy = doc.CrossSectionFace.Shape.MatrixOfInertia.A22  # Iyy
+force = doc.ConstraintForce.Force
+from FreeCAD import Units
+ym = Units.Quantity(doc.MechanicalMaterial.Material["YoungsModulus"]).getValueAs("MPa")
+w = force * len**3 / (3 * ym * iyy)
+w  # should print 149.0 mm
+
+CalculiX FEM max deflection:
+- 146.7 mm
+- Delta ca. 1.5 %
+
+"""
+
+
+def setup(doc=None, solvertype="ccxtools"):
+
+    # init FreeCAD document
+    if doc is None:
+        doc = init_doc()
+
+    # explanation object
+    # just keep the following line and change text string in get_explanation method
+    manager.add_explanation_obj(doc, get_explanation(manager.get_header(get_information())))
+
+    diameter = 1000
+    cs_wire = doc.addObject("Part::Circle", "WireOfCrossSection")
+    cs_wire.Radius = diameter / 2
+    cs_wire.Placement = FreeCAD.Placement(
+        FreeCAD.Vector(0, 500, 500),
+        FreeCAD.Rotation(0, 90, 0),
+        FreeCAD.Vector(0, 0, 0),
+    )
+    doc.recompute()
+    cs_face = doc.addObject("Part::Face", "CrossSectionFace")
+    cs_face.Sources = cs_wire
+    doc.recompute()
+
+    # setup CalculiX cantilever
+    doc = setup_cantilever_base_edge(doc, solvertype)
+    beamsection_obj = doc.getObject("BeamCrossSection")
+
+    # change cross section to a circular section
+    beamsection_obj.SectionType = "Circular"
+    beamsection_obj.CircDiameter = diameter
+
+    doc.recompute()
+    return doc
diff --git a/src/Mod/Fem/femexamples/ccx_cantilever_beam_pipe.py b/src/Mod/Fem/femexamples/ccx_cantilever_beam_pipe.py
@@ -0,0 +1,119 @@
+# ***************************************************************************
+# *   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                                                                   *
+# *                                                                         *
+# ***************************************************************************
+
+import FreeCAD
+
+from . import manager
+from .ccx_cantilever_base_edge import setup_cantilever_base_edge
+from .manager import init_doc
+
+
+def get_information():
+    return {
+        "name": "CCX cantilever beam pipe",
+        "meshtype": "edge",
+        "meshelement": "Seg3",
+        "constraints": ["fixed", "force"],
+        "solvers": ["calculix"],
+        "material": "solid",
+        "equation": "mechanical"
+    }
+
+
+def get_explanation(header=""):
+    return header + """
+
+To run the example from Python console use:
+from femexamples.ccx_cantilever_beam_pipe import setup
+setup()
+
+
+See forum topic post:
+https://forum.freecadweb.org/viewtopic.php?f=18&t=16044
+
+CalculiX cantilever:
+- modeled with seg3 beam elements
+
+CrossSection:
+- pipe
+- outer diameter 1000 mm
+- thickness 100 mm
+- inner diameter = 1000 - 2x100 = 800
+- inner radius = 1000/2 - 100 = 400
+
+max deflection:
+doc = App.ActiveDocument
+len = doc.CantileverLine.Shape.Length
+iyy = doc.CrossSectionFace.Shape.MatrixOfInertia.A22  # Iyy
+force = doc.ConstraintForce.Force
+from FreeCAD import Units
+ym = Units.Quantity(doc.MechanicalMaterial.Material["YoungsModulus"]).getValueAs("MPa")
+w = force * len**3 / (3 * ym * iyy)
+w  # should print 252.4 mm
+
+CalculiX FEM max deflection:
+- edit the solver input: element type B32R instead B32R
+- 249.8 mm
+- Delta ca. 1.0 %
+
+"""
+
+
+def setup(doc=None, solvertype="ccxtools"):
+
+    # init FreeCAD document
+    if doc is None:
+        doc = init_doc()
+
+    # explanation object
+    # just keep the following line and change text string in get_explanation method
+    manager.add_explanation_obj(doc, get_explanation(manager.get_header(get_information())))
+
+    diameter = 1000
+    thickness = 100
+    cs_wire_outer = doc.addObject("Part::Circle", "OuterWireOfCrossSection")
+    cs_wire_outer.Radius = diameter / 2
+    cs_wire_outer.Placement = FreeCAD.Placement(
+        FreeCAD.Vector(0, 500, 500),
+        FreeCAD.Rotation(0, 90, 0),
+        FreeCAD.Vector(0, 0, 0),
+    )
+    cs_wire_inner = doc.addObject("Part::Circle", "InnerWireOfCrossSection")
+    cs_wire_inner.Radius = (diameter / 2) - thickness
+    cs_wire_inner.Placement = cs_wire_outer.Placement
+    doc.recompute()
+    cs_face = doc.addObject("Part::Face", "CrossSectionFace")
+    cs_face.Sources = [cs_wire_outer, cs_wire_inner]
+    doc.recompute()
+
+    # setup CalculiX cantilever
+    doc = setup_cantilever_base_edge(doc, solvertype)
+    beamsection_obj = doc.getObject("BeamCrossSection")
+
+    # change cross section to a pipe section
+    beamsection_obj.SectionType = "Pipe"
+    beamsection_obj.PipeDiameter = diameter
+    beamsection_obj.PipeThickness = thickness
+
+    doc.recompute()
+    return doc
diff --git a/src/Mod/Fem/femexamples/ccx_cantilever_beam_rect.py b/src/Mod/Fem/femexamples/ccx_cantilever_beam_rect.py
@@ -0,0 +1,111 @@
+# ***************************************************************************
+# *   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                                                                   *
+# *                                                                         *
+# ***************************************************************************
+
+import FreeCAD
+
+from . import manager
+from .ccx_cantilever_base_edge import setup_cantilever_base_edge
+from .manager import init_doc
+
+
+def get_information():
+    return {
+        "name": "CCX cantilever beam rectangle",
+        "meshtype": "edge",
+        "meshelement": "Seg3",
+        "constraints": ["fixed", "force"],
+        "solvers": ["calculix"],
+        "material": "solid",
+        "equation": "mechanical"
+    }
+
+
+def get_explanation(header=""):
+    return header + """
+
+To run the example from Python console use:
+from femexamples.ccx_cantilever_beam_rect import setup
+setup()
+
+
+See forum topic post:
+https://forum.freecadweb.org/viewtopic.php?f=18&t=16044
+
+CalculiX cantilever:
+- modeled with seg3 beam elements
+
+CrossSection:
+- rectangle
+- width = 400 mm
+- height = 1250 mm
+
+max deflection:
+doc = App.ActiveDocument
+len = doc.CantileverLine.Shape.Length
+iyy = doc.CrossSectionFace.Shape.MatrixOfInertia.A22  # Iyy
+force = doc.ConstraintForce.Force
+from FreeCAD import Units
+ym = Units.Quantity(doc.MechanicalMaterial.Material["YoungsModulus"]).getValueAs("MPa")
+w = force * len**3 / (3 * ym * iyy)
+w  # should print 112.3 mm
+
+CalculiX FEM max deflection:
+- 112.2 mm
+- but the rotation seams 90 degree rotated (FIXME)
+
+"""
+
+
+def setup(doc=None, solvertype="ccxtools"):
+
+    # init FreeCAD document
+    if doc is None:
+        doc = init_doc()
+
+    # explanation object
+    # just keep the following line and change text string in get_explanation method
+    manager.add_explanation_obj(doc, get_explanation(manager.get_header(get_information())))
+
+    width = 400
+    height = 1250
+    cs_face = doc.addObject("Part::Plane", "CrossSectionFace")
+    cs_face.Width = width
+    cs_face.Length = height
+    cs_face.Placement = FreeCAD.Placement(
+        FreeCAD.Vector(0, 500 - 0.5 * width, 500 + 0.5 * height),
+        FreeCAD.Rotation(0, 90, 0),
+        FreeCAD.Vector(0, 0, 0),
+    )
+    doc.recompute()
+
+    # setup CalculiX cantilever
+    doc = setup_cantilever_base_edge(doc, solvertype)
+    beamsection_obj = doc.getObject("BeamCrossSection")
+
+    # change cross section to a circular section
+    beamsection_obj.SectionType = "Rectangular"
+    beamsection_obj.RectWidth = width
+    beamsection_obj.RectHeight = height
+
+    doc.recompute()
+    return doc