# *************************************************************************** # * Copyright (c) 2023 Uwe Stöhr * # * * # * 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 * # * * # *************************************************************************** __title__ = "FreeCAD FEM Elasticity Elmer writer" __author__ = "Uwe Stöhr" __url__ = "https://www.freecad.org" ## \addtogroup FEM # @{ from FreeCAD import Console from FreeCAD import Units from .. import sifio from .. import writer as general_writer from femtools import femutils class DeformationWriter: def __init__(self, writer, solver): self.write = writer self.solver = solver def getDeformationSolver(self, equation): s = self.write.createLinearSolver(equation) # output the equation parameters s = self.write.createNonlinearSolver(equation) s["Equation"] = "Nonlinear elasticity solver" s["Procedure"] = sifio.FileAttr("ElasticSolve/ElasticSolver") if equation.CalculateStrains is True: s["Calculate Strains"] = equation.CalculateStrains if equation.CalculateStresses is True: s["Calculate Stresses"] = equation.CalculateStresses if equation.CalculatePrincipal is True: s["Calculate Principal"] = equation.CalculatePrincipal if equation.CalculatePangle is True: s["Calculate Pangle"] = equation.CalculatePangle if equation.InitializeStateVariables is True: s["Initialize State Variables"] = equation.InitializeStateVariables if equation.MixedFormulation is True: s["Mixed Formulation"] = equation.MixedFormulation if equation.NeoHookeanMaterial is True: s["Neo-Hookean Material"] = equation.NeoHookeanMaterial s["Exec Solver"] = "Always" s["Optimize Bandwidth"] = True s["Stabilize"] = equation.Stabilize s["Variable"] = equation.Variable return s def handleDeformationEquation(self, bodies, equation): for b in bodies: # not for bodies with fluid material if not self.write.isBodyMaterialFluid(b): if equation.PlaneStress: self.write.equation(b, "Plane Stress", equation.PlaneStress) def handleDeformationConstants(self): pass def handleDeformationBndConditions(self): for obj in self.write.getMember("Fem::ConstraintPressure"): if obj.References: for name in obj.References[0][1]: pressure = self.write.getFromUi(obj.Pressure, "MPa", "M/(L*T^2)") if not obj.Reversed: pressure *= -1 self.write.boundary(name, "Normal Force", pressure) self.write.handled(obj) for obj in self.write.getMember("Fem::ConstraintFixed"): if obj.References: for name in obj.References[0][1]: self.write.boundary(name, "Displacement 1", 0.0) self.write.boundary(name, "Displacement 2", 0.0) self.write.boundary(name, "Displacement 3", 0.0) self.write.handled(obj) for obj in self.write.getMember("Fem::ConstraintForce"): if obj.References: for name in obj.References[0][1]: force = self.write.getFromUi(obj.Force, "N", "M*L*T^-2") self.write.boundary(name, "Force 1", obj.DirectionVector.x * force) self.write.boundary(name, "Force 2", obj.DirectionVector.y * force) self.write.boundary(name, "Force 3", obj.DirectionVector.z * force) self.write.boundary(name, "Force 1 Normalize by Area", True) self.write.boundary(name, "Force 2 Normalize by Area", True) self.write.boundary(name, "Force 3 Normalize by Area", True) self.write.handled(obj) for obj in self.write.getMember("Fem::ConstraintDisplacement"): if obj.References: for name in obj.References[0][1]: if obj.useFlowSurfaceForce: self.write.boundary(name, "FSI BC", obj.useFlowSurfaceForce) # if useFlowSurfaceForce no displacements must be output continue if not obj.xFree: if not obj.hasXFormula: displacement = float(obj.xDisplacement.getValueAs("m")) else: displacement = obj.xDisplacementFormula self.write.boundary(name, "Displacement 1", displacement) if not obj.yFree: if not obj.hasYFormula: displacement = float(obj.yDisplacement.getValueAs("m")) else: displacement = obj.yDisplacementFormula self.write.boundary(name, "Displacement 2", displacement) if not obj.zFree: if not obj.hasZFormula: displacement = float(obj.zDisplacement.getValueAs("m")) else: displacement = obj.zDisplacementFormula self.write.boundary(name, "Displacement 3", displacement) self.write.handled(obj) for obj in self.write.getMember("Fem::ConstraintSpring"): if obj.References: for name in obj.References[0][1]: if obj.ElmerStiffness == "Normal Stiffness": spring = float(obj.NormalStiffness.getValueAs("N/m")) else: spring = float(obj.TangentialStiffness.getValueAs("N/m")) self.write.boundary(name, "Spring", spring) self.write.handled(obj) def handleDeformationInitial(self, bodies): pass def handleDeformationBodyForces(self, bodies): obj = self.write.getSingleMember("Fem::ConstraintSelfWeight") if obj is not None: for name in bodies: gravity = self.write.convert(self.write.constsdef["Gravity"], "L/T^2") if self.write.getBodyMaterial(name) is None: raise general_writer.WriteError( "The body {} is not referenced in any material.\n\n".format(name) ) m = self.write.getBodyMaterial(name).Material densityQuantity = Units.Quantity(m["Density"]) dimension = "M/L^3" if name.startswith("Edge"): # not tested, bernd # TODO: test densityQuantity.Unit = Units.Unit(-2, 1) dimension = "M/L^2" density = self.write.convert(densityQuantity, dimension) force1 = gravity * obj.Gravity_x * density force2 = gravity * obj.Gravity_y * density force3 = gravity * obj.Gravity_z * density self.write.bodyForce(name, "Stress Bodyforce 1", force1) self.write.bodyForce(name, "Stress Bodyforce 2", force2) self.write.bodyForce(name, "Stress Bodyforce 3", force3) self.write.handled(obj) def handleDeformationMaterial(self, bodies): # density # is needed for self weight constraints and frequency analysis density_needed = False for equation in self.solver.Group: if femutils.is_of_type(equation, "Fem::EquationElmerElasticity"): if equation.EigenAnalysis is True: density_needed = True break # there could be a second equation without frequency gravObj = self.write.getSingleMember("Fem::ConstraintSelfWeight") if gravObj is not None: density_needed = True # temperature tempObj = self.write.getSingleMember("Fem::ConstraintInitialTemperature") if tempObj is not None: refTemp = float(tempObj.initialTemperature.getValueAs("K")) for name in bodies: self.write.material(name, "Reference Temperature", refTemp) # get the material data for all bodies for obj in self.write.getMember("App::MaterialObject"): m = obj.Material refs = ( obj.References[0][1] if obj.References else self.write.getAllBodies() ) for name in (n for n in refs if n in bodies): # don't evaluate fluid material if self.write.isBodyMaterialFluid(name): break if "YoungsModulus" not in m: Console.PrintMessage("m: {}\n".format(m)) # it is no fluid but also no solid # -> user set no material reference at all # that now material is known raise general_writer.WriteError( "There are two or more materials with empty references.\n\n" "Set for the materials to what solid they belong to.\n" ) self.write.material(name, "Name", m["Name"]) if density_needed is True: self.write.material( name, "Density", self.write.getDensity(m) ) self.write.material( name, "Youngs Modulus", self._getYoungsModulus(m) ) self.write.material( name, "Poisson ratio", float(m["PoissonRatio"]) ) if tempObj: self.write.material( name, "Heat expansion Coefficient", self.write.convert(m["ThermalExpansionCoefficient"], "O^-1") ) def _getYoungsModulus(self, m): youngsModulus = self.write.convert(m["YoungsModulus"], "M/(L*T^2)") if self.write.getMeshDimension() == 2: youngsModulus *= 1e3 return youngsModulus ## @}