Fem: Add body heat source to CalculiX writer - fixes FreeCAD#11650

Author: marioalexis84

src/Mod/Fem/CMakeLists.txt

@@ -221,6 +221,7 @@ SET(FemSolverCalculix_SRCS
     femsolver/calculix/__init__.py
     femsolver/calculix/solver.py
     femsolver/calculix/tasks.py
+    femsolver/calculix/write_constraint_bodyheatsource.py
     femsolver/calculix/write_constraint_centrif.py
     femsolver/calculix/write_constraint_contact.py
     femsolver/calculix/write_constraint_displacement.py

src/Mod/Fem/femmesh/meshsetsgetter.py

@@ -135,6 +135,7 @@ def get_mesh_sets(self):
 
         # constraints element sets getter
         self.get_constraints_centrif_elements()
+        self.get_constraints_bodyheatsource_elements()
 
         # constraints node sets getter
         self.get_constraints_fixed_nodes()
@@ -540,6 +541,18 @@ def get_constraints_centrif_elements(self):
         else:
             self.get_solid_element_sets(self.member.cons_centrif)
 
+    def get_constraints_bodyheatsource_elements(self):
+        # get element ids and write them into the femobj
+        if not self.member.cons_bodyheatsource:
+            return
+        if (
+            len(self.member.cons_bodyheatsource) == 1
+            and not self.member.cons_bodyheatsource[0]["Object"].References
+        ):
+            self.member.cons_bodyheatsource[0]["FEMElements"] = self.ccx_evolumes
+        else:
+            self.get_solid_element_sets(self.member.cons_bodyheatsource)
+
     # ********************************************************************************************
     # ********************************************************************************************
     # element sets material and element geometry

src/Mod/Fem/femmesh/meshtools.py

@@ -784,6 +784,8 @@ def get_elset_short_name(
         return "S" + str(i)
     elif is_of_type(obj, "Fem::ConstraintCentrif"):
         return "C" + str(i)
+    elif is_of_type(obj, "Fem::ConstraintBodyHeatSource"):
+        return "H" + str(i)
     else:
         FreeCAD.Console.PrintError(
             "Error in creating short elset name "

src/Mod/Fem/femsolver/calculix/write_constraint_bodyheatsource.py

@@ -0,0 +1,96 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+#/***************************************************************************
+# *   Copyright (c) 2024 Mario Passaglia <mpassaglia[at]cbc.uba.ar>         *
+# *                                                                         *
+# *   This file is part of FreeCAD.                                         *
+# *                                                                         *
+# *   FreeCAD is free software: you can redistribute it and/or modify it    *
+# *   under the terms of the GNU Lesser General Public License as           *
+# *   published by the Free Software Foundation, either version 2.1 of the  *
+# *   License, or (at your option) any later version.                       *
+# *                                                                         *
+# *   FreeCAD 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      *
+# *   Lesser General Public License for more details.                       *
+# *                                                                         *
+# *   You should have received a copy of the GNU Lesser General Public      *
+# *   License along with FreeCAD. If not, see                               *
+# *   <https://www.gnu.org/licenses/>.                                      *
+# *                                                                         *
+# **************************************************************************
+
+__title__ = "FreeCAD FEM calculix constraint body heat source"
+__author__ = "Mario Passaglia"
+__url__ = "https://www.freecad.org"
+
+
+import FreeCAD
+
+
+def get_analysis_types():
+    return ["thermomech"]
+
+
+def get_sets_name():
+    return "constraints_bodyheatsource_element_sets"
+
+
+def get_constraint_title():
+    return "Body Heat Source Constraints"
+
+
+def get_before_write_meshdata_constraint():
+    return ""
+
+
+def get_after_write_meshdata_constraint():
+    return ""
+
+
+def get_before_write_constraint():
+    return ""
+
+
+def get_after_write_constraint():
+    return ""
+
+
+def write_meshdata_constraint(f, femobj, bodyheatsource_obj, ccxwriter):
+    f.write("*ELSET,ELSET={}\n".format(bodyheatsource_obj.Name))
+    if isinstance(femobj["FEMElements"], str):
+        f.write("{}\n".format(femobj["FEMElements"]))
+    else:
+        for e in femobj["FEMElements"]:
+            f.write("{},\n".format(e))
+
+
+def write_constraint(f, femobj, bodyheatsource_obj, ccxwriter):
+
+    # floats read from ccx should use {:.13G}, see comment in writer module
+    # search referenced material
+    ref = bodyheatsource_obj.References
+    density = None
+    for mat in ccxwriter.member.mats_linear:
+        for mat_ref in mat["Object"].References:
+            if mat_ref[0] == ref[0]:
+                density = FreeCAD.Units.Quantity(mat["Object"].Material["Density"])
+                break
+
+    if not density:
+        # search material without references
+        for mat in ccxwriter.member.mats_linear:
+            if not mat["Object"].References:
+                density = FreeCAD.Units.Quantity(mat["Object"].Material["Density"])
+
+    # get some data from the bodyheatsource_obj (is in power per unit mass)
+    heat = FreeCAD.Units.Quantity(bodyheatsource_obj.HeatSource, "m^2/s^3") * density
+    # write to file
+    f.write("*DFLUX\n")
+    f.write(
+        "{},BF,{:.13G}\n".format(
+            bodyheatsource_obj.Name, heat.getValueAs("t/(mm*s^3)").Value
+        )
+    )
+    f.write("\n")

src/Mod/Fem/femsolver/calculix/writer.py

@@ -36,6 +36,7 @@
 from FreeCAD import Units
 
 from . import write_constraint_centrif as con_centrif
+from . import write_constraint_bodyheatsource as con_bodyheatsource
 from . import write_constraint_contact as con_contact
 from . import write_constraint_displacement as con_displacement
 from . import write_constraint_fixed as con_fixed
@@ -160,6 +161,7 @@ def write_solver_input(self):
 
         # element sets constraints
         self.write_constraints_meshsets(inpfile, self.member.cons_centrif, con_centrif)
+        self.write_constraints_meshsets(inpfile, self.member.cons_bodyheatsource, con_bodyheatsource)
 
         # node sets
         self.write_constraints_meshsets(inpfile, self.member.cons_fixed, con_fixed)
@@ -196,6 +198,7 @@ def write_solver_input(self):
         self.write_constraints_propdata(inpfile, self.member.cons_sectionprint, con_sectionprint)
         self.write_constraints_propdata(inpfile, self.member.cons_selfweight, con_selfweight)
         self.write_constraints_propdata(inpfile, self.member.cons_centrif, con_centrif)
+        self.write_constraints_propdata(inpfile, self.member.cons_bodyheatsource, con_bodyheatsource)
         self.write_constraints_meshsets(inpfile, self.member.cons_force, con_force)
         self.write_constraints_meshsets(inpfile, self.member.cons_pressure, con_pressure)
         self.write_constraints_propdata(inpfile, self.member.cons_temperature, con_temperature)

src/Mod/Fem/femtools/membertools.py

@@ -289,6 +289,9 @@ def __init__(self, analysis):
         self.cons_centrif = self.get_several_member(
             "Fem::ConstraintCentrif"
         )
+        self.cons_bodyheatsource = self.get_several_member(
+            "Fem::ConstraintBodyHeatSource"
+        )
         self.cons_contact = self.get_several_member(
             "Fem::ConstraintContact"
         )