# *************************************************************************** # * Copyright (c) 2021 Bernd Hahnebach * # * * # * 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 BOPTools import SplitFeatures import Fem import ObjectsFem from . import manager from .manager import get_meshname from .manager import init_doc def get_information(): return { "name": "Mystran Plate", "meshtype": "face", "meshelement": "Quad4", "constraints": ["fixed", "force"], "solvers": ["calculix", "ccxtools", "elmer", "mystran"], "material": "solid", "equations": ["mechanical"] } def get_explanation(header=""): return header + """ To run the example from Python console use: from femexamples.buckling_platebuckling import setup setup() See forum topic post: https://forum.freecad.org/viewtopic.php?f=18&t=60320&start=10#p517884 This version here uses some real value for the Young's Modulus The CalculiX steel is used plate 10 mm x 10 mm * 0.3 mm one each mesh node on one edge 100 N tension force Does not work on Z88 because Z88 does not support quad4 elements """ 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()))) # geometric object plate = doc.addObject("Part::Plane", "Plate") plate.Width = 10 plate.Length = 10 force_pt1 = doc.addObject("Part::Vertex", "ForcePT1") force_pt1.X = 10 force_pt1.Y = 2 force_pt2 = doc.addObject("Part::Vertex", "ForcePT2") force_pt2.X = 10 force_pt2.Y = 4 force_pt3 = doc.addObject("Part::Vertex", "ForcePT3") force_pt3.X = 10 force_pt3.Y = 6 force_pt4 = doc.addObject("Part::Vertex", "ForcePT4") force_pt4.X = 10 force_pt4.Y = 8 doc.recompute() # all geom boolean fragment geom_obj = SplitFeatures.makeBooleanFragments(name='ThePointPlate') geom_obj.Objects = [plate, force_pt1, force_pt2, force_pt3, force_pt4] doc.recompute() if FreeCAD.GuiUp: plate.ViewObject.hide() force_pt1.ViewObject.hide() force_pt2.ViewObject.hide() force_pt3.ViewObject.hide() force_pt4.ViewObject.hide() doc.recompute() if FreeCAD.GuiUp: geom_obj.ViewObject.PointSize = 10 geom_obj.ViewObject.Document.activeView().viewAxonometric() geom_obj.ViewObject.Document.activeView().fitAll() # analysis analysis = ObjectsFem.makeAnalysis(doc, "Analysis") # solver if solvertype == "calculix": solver_obj = ObjectsFem.makeSolverCalculix(doc, "SolverCalculiX") elif solvertype == "ccxtools": solver_obj = ObjectsFem.makeSolverCalculixCcxTools(doc, "CalculiXccxTools") solver_obj.WorkingDir = u"" elif solvertype == "elmer": solver_obj = ObjectsFem.makeSolverElmer(doc, "SolverElmer") ObjectsFem.makeEquationElasticity(doc, solver_obj) elif solvertype == "mystran": solver_obj = ObjectsFem.makeSolverMystran(doc, "SolverMystran") elif solvertype == "z88": solver_obj = ObjectsFem.makeSolverZ88(doc, "SolverZ88") else: FreeCAD.Console.PrintWarning( "Unknown or unsupported solver type: {}. " "No solver object was created.\n".format(solvertype) ) if solvertype == "calculix" or solvertype == "ccxtools": solver_obj.SplitInputWriter = False solver_obj.AnalysisType = "static" solver_obj.GeometricalNonlinearity = "linear" solver_obj.ThermoMechSteadyState = False solver_obj.MatrixSolverType = "default" solver_obj.IterationsControlParameterTimeUse = False analysis.addObject(solver_obj) # shell thickness thickness_obj = ObjectsFem.makeElementGeometry2D(doc, 0.3, 'Thickness') analysis.addObject(thickness_obj) # material material_obj = ObjectsFem.makeMaterialSolid(doc, "FemMaterial") mat = material_obj.Material mat["Name"] = "CalculiX-Steel" mat["YoungsModulus"] = "210000 MPa" mat["PoissonRatio"] = "0.30" material_obj.Material = mat analysis.addObject(material_obj) # constraint fixed con_fixed = ObjectsFem.makeConstraintFixed(doc, "ConstraintFixed") con_fixed.References = [(geom_obj, "Edge1")] analysis.addObject(con_fixed) # constraint force con_force = ObjectsFem.makeConstraintForce(doc, "ConstraintForce") con_force.References = [ (geom_obj, "Vertex7"), (geom_obj, "Vertex1"), (geom_obj, "Vertex2"), (geom_obj, "Vertex3"), (geom_obj, "Vertex4"), (geom_obj, "Vertex8"), ] con_force.Force = 600 # 600 N on six nodes == 100 N/Node con_force.Reversed = False con_force.Direction = (geom_obj, ["Edge2"]) analysis.addObject(con_force) # mesh from .meshes.mesh_plate_mystran_quad4 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, get_meshname()))[0] femmesh_obj.FemMesh = fem_mesh femmesh_obj.Part = geom_obj femmesh_obj.SecondOrderLinear = False femmesh_obj.CharacteristicLengthMax = "1.0 mm" femmesh_obj.ElementDimension = "2D" femmesh_obj.ElementOrder = "1st" doc.recompute() return doc