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

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This commit is contained in:
Bernd Hahnebach
2021-08-03 20:02:04 +02:00
parent d1d9b633b9
commit 0ff4cde3ff
5 changed files with 344 additions and 0 deletions
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3
src/Mod/Fem/CMakeLists.txt
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@@ -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

1
src/Mod/Fem/femexamples/ccx_cantilever_base_edge.py
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@@ -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()

110
src/Mod/Fem/femexamples/ccx_cantilever_beam_circle.py Normal file
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@@ -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

119
src/Mod/Fem/femexamples/ccx_cantilever_beam_pipe.py Normal file
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@@ -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

111
src/Mod/Fem/femexamples/ccx_cantilever_beam_rect.py Normal file
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@@ -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