diff --git a/src/Mod/Fem/femguiutils/selection_widgets.py b/src/Mod/Fem/femguiutils/selection_widgets.py
index 19fe48ba25..c7ae25c214 100644
--- a/src/Mod/Fem/femguiutils/selection_widgets.py
+++ b/src/Mod/Fem/femguiutils/selection_widgets.py
@@ -235,13 +235,11 @@ class GeometryElementsSelection(QtGui.QWidget):
         super(GeometryElementsSelection, self).__init__()
         # init ui stuff
         FreeCADGui.Selection.clearSelection()
-        self.selection_mode_solid = False
         self.sel_server = None
         self.obj_notvisible = []
         self.initElemTypes(eltypes)
         self.allow_multiple_geom_types = multigeom
         self.showHintEmptyList = showHintEmptyList
-        # print(self.allow_multiple_geom_types)
         self.initUI()
         # set references and fill the list widget
         self.references = []
@@ -280,24 +278,20 @@ class GeometryElementsSelection(QtGui.QWidget):
         self._helpTextLbl = QtGui.QLabel()
         self._helpTextLbl.setWordWrap(True)
         helpTextPart1 = self.tr(
-            'Click on "Add" and select geometric elements to add to the list.'
+            'Click on "Add" and select geometric elements to add them to the list.{}'
+            "The following geometry elements are allowed to select: {}{}{}"
+            .format("<br>", "<b>", self.sel_elem_text, "</b>")
         )
-        helpTextPart2 = self.tr(
-            "The following geometry elements are allowed to select: "
-        ) + self.sel_elem_text
-        helpTextPart3 = self.tr(
-            "If no geometry is added to the list, all remaining ones are used."
+        helpTextEmpty = self.tr(
+            "{}If no geometry is added to the list, all remaining ones are used.".format("<br>")
         )
         if self.showHintEmptyList is True:
             self._helpTextLbl.setText(
-                helpTextPart1 + "\n"
-                + helpTextPart2 + "\n"
-                + helpTextPart3
+                helpTextPart1 + helpTextEmpty
             )
         else:
             self._helpTextLbl.setText(
-                helpTextPart1 + "\n"
-                + helpTextPart2
+                helpTextPart1
             )
         # list
         self.list_References = QtGui.QListWidget()
@@ -306,9 +300,7 @@ class GeometryElementsSelection(QtGui.QWidget):
         self.lb_selmod.setText(self.tr("Selection mode"))
         self.rb_standard = QtGui.QRadioButton(self.tr(self.sel_elem_text.lstrip("Solid, ")))
         self.rb_solid = QtGui.QRadioButton(self.tr("Solid"))
-        self.rb_standard.setChecked(True)
-        self.rb_solid.setChecked(False)
-        # radio butoon layout
+        # radio button layout
         rbtnLayout = QtGui.QHBoxLayout()
         rbtnLayout.addWidget(self.lb_selmod)
         rbtnLayout.addWidget(self.rb_standard)
@@ -318,8 +310,19 @@ class GeometryElementsSelection(QtGui.QWidget):
         mainLayout.addWidget(self._helpTextLbl)
         mainLayout.addWidget(self.pushButton_Add)
         mainLayout.addWidget(self.list_References)
-        if "Solid" in self.sel_elem_types:
+
+        # if only "Solid" is avail, std-sel-mode is obsolete
+        if "Solid" in self.sel_elem_types and len(self.sel_elem_types) == 1:
+            self.selection_mode_solid = True
+        else:
+            self.selection_mode_solid = False
+
+        # show radio buttons, if a solid and at least one nonsolid is allowed
+        if "Solid" in self.sel_elem_types and len(self.sel_elem_types) > 1:
+            self.rb_standard.setChecked(True)
+            self.rb_solid.setChecked(False)
             mainLayout.addLayout(rbtnLayout)
+
         self.setLayout(mainLayout)
         # signals and slots
         self.list_References.itemSelectionChanged.connect(self.select_clicked_reference_shape)
diff --git a/src/Mod/Fem/femsolver/calculix/writer.py b/src/Mod/Fem/femsolver/calculix/writer.py
index 429d2fea80..7df2fca43d 100644
--- a/src/Mod/Fem/femsolver/calculix/writer.py
+++ b/src/Mod/Fem/femsolver/calculix/writer.py
@@ -265,29 +265,52 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
         return inpfile
 
     # ********************************************************************************************
-    # constraints fixed
-    def write_node_sets_constraints_fixed(self, f):
-        if not self.fixed_objects:
+    # write constraint node sets, constraint face sets, constraint element sets
+    def write_constraints_sets(
+        self,
+        f,
+        femobjs,
+        analysis_types,
+        sets_getter_method,
+        write_name,
+        sets_writer_method,
+        caller_method_name="",
+    ):
+        if not femobjs:
             return
-        # write for all analysis types
 
-        # get nodes
-        self.get_constraints_fixed_nodes()
+        if analysis_types != "all" and self.analysis_type not in analysis_types:
+            return
 
-        write_name = "constraints_fixed_node_sets"
-        f.write("\n***********************************************************\n")
+        # get the sets
+        sets_getter_method()
+
+        f.write("\n{}\n".format(59 * "*"))
         f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
+        f.write("** written by {} function\n".format(caller_method_name))
 
         if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
+            file_name_split = "{}_{}.inp".format(self.mesh_name, write_name)
             f.write("** {}\n".format(write_name.replace("_", " ")))
             f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
             inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_node_sets_nodes_constraints_fixed(inpfile_split)
+            sets_writer_method(inpfile_split)
             inpfile_split.close()
         else:
-            self.write_node_sets_nodes_constraints_fixed(f)
+            sets_writer_method(f)
+
+    # ********************************************************************************************
+    # constraints fixed
+    def write_node_sets_constraints_fixed(self, f):
+        self.write_constraints_sets(
+            f,
+            femobjs=self.fixed_objects,
+            analysis_types="all",  # write for all analysis types
+            sets_getter_method=self.get_constraints_fixed_nodes,
+            write_name="constraints_fixed_node_sets",
+            sets_writer_method=self.write_node_sets_nodes_constraints_fixed,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_node_sets_nodes_constraints_fixed(self, f):
         # write nodes to file
@@ -354,27 +377,15 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints displacement
     def write_node_sets_constraints_displacement(self, f):
-        if not self.displacement_objects:
-            return
-        # write for all analysis types
-
-        # get nodes
-        self.get_constraints_displacement_nodes()
-
-        write_name = "constraints_displacement_node_sets"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_node_sets_nodes_constraints_displacement(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_node_sets_nodes_constraints_displacement(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.displacement_objects,
+            analysis_types="all",  # write for all analysis types
+            sets_getter_method=self.get_constraints_displacement_nodes,
+            write_name="constraints_displacement_node_sets",
+            sets_writer_method=self.write_node_sets_nodes_constraints_displacement,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_node_sets_nodes_constraints_displacement(self, f):
         # write nodes to file
@@ -432,27 +443,15 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints planerotation
     def write_node_sets_constraints_planerotation(self, f):
-        if not self.planerotation_objects:
-            return
-        # write for all analysis types
-
-        # get nodes
-        self.get_constraints_planerotation_nodes()
-
-        write_name = "constraints_planerotation_node_sets"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_node_sets_nodes_constraints_planerotation(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_node_sets_nodes_constraints_planerotation(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.planerotation_objects,
+            analysis_types="all",  # write for all analysis types
+            sets_getter_method=self.get_constraints_planerotation_nodes,
+            write_name="constraints_planerotation_node_sets",
+            sets_writer_method=self.write_node_sets_nodes_constraints_planerotation,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_node_sets_nodes_constraints_planerotation(self, f):
         # write nodes to file
@@ -515,27 +514,15 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints contact
     def write_surfaces_constraints_contact(self, f):
-        if not self.contact_objects:
-            return
-        # write for all analysis types
-
-        # get faces
-        self.get_constraints_contact_faces()
-
-        write_name = "constraints_contact_surface_sets"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_surfacefaces_constraints_contact(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_surfacefaces_constraints_contact(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.contact_objects,
+            analysis_types="all",  # write for all analysis types
+            sets_getter_method=self.get_constraints_contact_faces,
+            write_name="constraints_contact_surface_sets",
+            sets_writer_method=self.write_surfacefaces_constraints_contact,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_surfacefaces_constraints_contact(self, f):
         # write faces to file
@@ -585,27 +572,15 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints tie
     def write_surfaces_constraints_tie(self, f):
-        if not self.tie_objects:
-            return
-        # write for all analysis types
-
-        # get faces
-        self.get_constraints_tie_faces()
-
-        write_name = "constraints_tie_surface_sets"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_surfacefaces_constraints_tie(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_surfacefaces_constraints_tie(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.tie_objects,
+            analysis_types="all",  # write for all analysis types
+            sets_getter_method=self.get_constraints_tie_faces,
+            write_name="constraints_tie_surface_sets",
+            sets_writer_method=self.write_surfacefaces_constraints_tie,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_surfacefaces_constraints_tie(self, f):
         # write faces to file
@@ -647,26 +622,18 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints sectionprint
     def write_surfaces_constraints_sectionprint(self, f):
-        if not self.sectionprint_objects:
-            return
-        # write for all analysis types
-
-        write_name = "constraints_sectionprint_surface_sets"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_surfacefaces_constraints_sectionprint(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_surfacefaces_constraints_sectionprint(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.sectionprint_objects,
+            analysis_types="all",  # write for all analysis types
+            sets_getter_method=self.get_constraints_sectionprint_faces,
+            write_name="constraints_sectionprint_surface_sets",
+            sets_writer_method=self.write_surfacefaces_constraints_sectionprint,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     # TODO move code parts from this method to base writer module
+    # into get_constraints_sectionprint_faces method
     def write_surfacefaces_constraints_sectionprint(self, f):
         # get surface nodes and write them to file
         obj = 0
@@ -724,27 +691,15 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints transform
     def write_node_sets_constraints_transform(self, f):
-        if not self.transform_objects:
-            return
-        # write for all analysis types
-
-        # get nodes
-        self.get_constraints_transform_nodes()
-
-        write_name = "constraints_transform_node_sets"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_node_sets_nodes_constraints_transform(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_node_sets_nodes_constraints_transform(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.transform_objects,
+            analysis_types="all",  # write for all analysis types
+            sets_getter_method=self.get_constraints_transform_nodes,
+            write_name="constraints_transform_node_sets",
+            sets_writer_method=self.write_node_sets_nodes_constraints_transform,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_node_sets_nodes_constraints_transform(self, f):
         # write nodes to file
@@ -798,28 +753,15 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints temperature
     def write_node_sets_constraints_temperature(self, f):
-        if not self.temperature_objects:
-            return
-        if not self.analysis_type == "thermomech":
-            return
-
-        # get nodes
-        self.get_constraints_temperature_nodes()
-
-        write_name = "constraints_temperature_node_sets"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_node_sets_nodes_constraints_temperature(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_node_sets_nodes_constraints_temperature(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.temperature_objects,
+            analysis_types=["thermomech"],
+            sets_getter_method=self.get_constraints_temperature_nodes,
+            write_name="constraints_temperature_node_sets",
+            sets_writer_method=self.write_node_sets_nodes_constraints_temperature,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_node_sets_nodes_constraints_temperature(self, f):
         # write nodes to file
@@ -862,7 +804,7 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     def write_constraints_initialtemperature(self, f):
         if not self.initialtemperature_objects:
             return
-        if not self.analysis_type == "thermomech":
+        if self.analysis_type not in ["thermomech"]:
             return
 
         # write constraint to file
@@ -880,11 +822,7 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     def write_constraints_selfweight(self, f):
         if not self.selfweight_objects:
             return
-        if not (
-            self.analysis_type == "static"
-            or self.analysis_type == "thermomech"
-            or self.analysis_type == "buckling"
-        ):
+        if self.analysis_type not in ["buckling", "static", "thermomech"]:
             return
 
         # write constraint to file
@@ -916,32 +854,15 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints force
     def write_constraints_force(self, f):
-        if not self.force_objects:
-            return
-        if not (
-            self.analysis_type == "static"
-            or self.analysis_type == "thermomech"
-            or self.analysis_type == "buckling"
-        ):
-            return
-
-        # check shape type of reference shape and get node loads
-        self.get_constraints_force_nodeloads()
-
-        write_name = "constraints_force_node_loads"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_nodeloads_constraints_force(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_nodeloads_constraints_force(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.force_objects,
+            analysis_types=["buckling", "static", "thermomech"],
+            sets_getter_method=self.get_constraints_force_nodeloads,
+            write_name="constraints_force_node_loads",
+            sets_writer_method=self.write_nodeloads_constraints_force,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_nodeloads_constraints_force(self, f):
         # write node loads to file
@@ -969,32 +890,15 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints pressure
     def write_constraints_pressure(self, f):
-        if not self.pressure_objects:
-            return
-        if not (
-            self.analysis_type == "static"
-            or self.analysis_type == "thermomech"
-            or self.analysis_type == "buckling"
-        ):
-            return
-
-        # get the faces and face numbers
-        self.get_constraints_pressure_faces()
-
-        write_name = "constraints_pressure_element_face_loads"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_faceloads_constraints_pressure(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_faceloads_constraints_pressure(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.pressure_objects,
+            analysis_types=["buckling", "static", "thermomech"],
+            sets_getter_method=self.get_constraints_pressure_faces,
+            write_name="constraints_pressure_element_face_loads",
+            sets_writer_method=self.write_faceloads_constraints_pressure,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
     def write_faceloads_constraints_pressure(self, f):
         # write face loads to file
@@ -1024,26 +928,18 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
     # ********************************************************************************************
     # constraints heatflux
     def write_constraints_heatflux(self, f):
-        if not self.heatflux_objects:
-            return
-        if not self.analysis_type == "thermomech":
-            return
-
-        write_name = "constraints_heatflux_element_face_heatflux"
-        f.write("\n***********************************************************\n")
-        f.write("** {}\n".format(write_name.replace("_", " ")))
-        f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-
-        if self.split_inpfile is True:
-            file_name_split = self.mesh_name + "_" + write_name + ".inp"
-            f.write("** {}\n".format(write_name.replace("_", " ")))
-            f.write("*INCLUDE,INPUT={}\n".format(file_name_split))
-            inpfile_split = open(join(self.dir_name, file_name_split), "w")
-            self.write_faceheatflux_constraints_heatflux(inpfile_split)
-            inpfile_split.close()
-        else:
-            self.write_faceheatflux_constraints_heatflux(f)
+        self.write_constraints_sets(
+            f,
+            femobjs=self.heatflux_objects,
+            analysis_types=["thermomech"],
+            sets_getter_method=self.get_constraints_heatflux_faces,
+            write_name="constraints_heatflux_element_face_heatflux",
+            sets_writer_method=self.write_faceheatflux_constraints_heatflux,
+            caller_method_name=sys._getframe().f_code.co_name,
+        )
 
+    # TODO move code parts from this method to base writer module
+    # into get_constraints_heatflux_faces method
     def write_faceheatflux_constraints_heatflux(self, f):
         # write heat flux faces to file
         for hfobj in self.heatflux_objects:
@@ -1083,10 +979,11 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
 
     # ********************************************************************************************
     # constraints fluidsection
+    # TODO: split method into separate methods and move some part into base writer
     def write_constraints_fluidsection(self, f):
         if not self.fluidsection_objects:
             return
-        if not self.analysis_type == "thermomech":
+        if self.analysis_type not in ["thermomech"]:
             return
 
         # write constraint to file
@@ -1765,17 +1662,21 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
             ccx_elset["ccx_mat_name"] = mat_obj.Material["Name"]
             self.ccx_elsets.append(ccx_elset)
 
+    def is_density_needed(self):
+        if self.analysis_type == "frequency":
+            return True
+        if self.analysis_type == "thermomech" and not self.solver_obj.ThermoMechSteadyState:
+            return True
+        if self.selfweight_objects:
+            return True
+        return False
+
     def write_materials(self, f):
         f.write("\n***********************************************************\n")
         f.write("** Materials\n")
         f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
         f.write("** Young\'s modulus unit is MPa = N/mm2\n")
-        if self.analysis_type == "frequency" \
-                or self.selfweight_objects \
-                or (
-                    self.analysis_type == "thermomech"
-                    and not self.solver_obj.ThermoMechSteadyState
-                ):
+        if self.is_density_needed() is True:
             f.write("** Density\'s unit is t/mm^3\n")
         if self.analysis_type == "thermomech":
             f.write("** Thermal conductivity unit is kW/mm/K = t*mm/K*s^3\n")
@@ -1791,12 +1692,7 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
                 YM = FreeCAD.Units.Quantity(mat_obj.Material["YoungsModulus"])
                 YM_in_MPa = float(YM.getValueAs("MPa"))
                 PR = float(mat_obj.Material["PoissonRatio"])
-            if self.analysis_type == "frequency" \
-                    or self.selfweight_objects \
-                    or (
-                        self.analysis_type == "thermomech"
-                        and not self.solver_obj.ThermoMechSteadyState
-                    ):
+            if self.is_density_needed() is True:
                 density = FreeCAD.Units.Quantity(mat_obj.Material["Density"])
                 density_in_tonne_per_mm3 = float(density.getValueAs("t/mm^3"))
             if self.analysis_type == "thermomech":
@@ -1821,12 +1717,7 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
                 f.write("*ELASTIC\n")
                 f.write("{0:.0f}, {1:.3f}\n".format(YM_in_MPa, PR))
 
-            if self.analysis_type == "frequency" \
-                    or self.selfweight_objects \
-                    or (
-                        self.analysis_type == "thermomech"
-                        and not self.solver_obj.ThermoMechSteadyState
-                    ):
+            if self.is_density_needed() is True:
                 f.write("*DENSITY\n")
                 f.write("{0:.3e}\n".format(density_in_tonne_per_mm3))
             if self.analysis_type == "thermomech":
diff --git a/src/Mod/Fem/femsolver/writerbase.py b/src/Mod/Fem/femsolver/writerbase.py
index 47a460f8f1..295bc13678 100644
--- a/src/Mod/Fem/femsolver/writerbase.py
+++ b/src/Mod/Fem/femsolver/writerbase.py
@@ -394,6 +394,14 @@ class FemInputWriter():
             # FreeCAD.Console.PrintLog("{}\n".format(femobj["ContactSlaveFaces"]))
             # FreeCAD.Console.PrintLog("{}\n".format(femobj["ContactMasterFaces"]))
 
+    def get_constraints_sectionprint_faces(self):
+        pass
+        # TODO implement
+
+    def get_constraints_heatflux_faces(self):
+        pass
+        # TODO implement
+
     # ********************************************************************************************
     # ********************************************************************************************
     # element sets
diff --git a/src/Mod/Fem/femtest/app/test_ccxtools.py b/src/Mod/Fem/femtest/app/test_ccxtools.py
index 1f600347fd..3d0ccfd0e8 100644
--- a/src/Mod/Fem/femtest/app/test_ccxtools.py
+++ b/src/Mod/Fem/femtest/app/test_ccxtools.py
@@ -87,7 +87,7 @@ class TestCcxTools(unittest.TestCase):
         from femexamples.boxanalysis_frequency import setup
         setup(self.document, "ccxtools")
         base_name = get_namefromdef("test_")
-        res_obj_name = "CCX_Mode1_Results"
+        res_obj_name = "CCX_EigenMode_1_Results"
         analysis_dir = testtools.get_fem_test_tmp_dir(self.pre_dir_name + base_name)
 
         # test input file writing
@@ -98,7 +98,6 @@ class TestCcxTools(unittest.TestCase):
             test_end=True,
         )
 
-        """ temporary deactivate test due to 79b41f739381
         # test result reading
         self.result_reading_test(
             None,
@@ -107,7 +106,6 @@ class TestCcxTools(unittest.TestCase):
             fea=fea,
             res_obj_name=res_obj_name,
         )
-        """
 
     # ********************************************************************************************
     def test_box_static(
@@ -145,7 +143,7 @@ class TestCcxTools(unittest.TestCase):
         from femexamples.thermomech_flow1d import setup
         setup(self.document, "ccxtools")
         base_name = get_namefromdef("test_")
-        res_obj_name = "CCX_Time1_0_Results"
+        res_obj_name = "CCX_Time_1_0_Results"
         analysis_dir = testtools.get_fem_test_tmp_dir(self.pre_dir_name + base_name)
 
         # test input file writing
@@ -156,7 +154,6 @@ class TestCcxTools(unittest.TestCase):
             test_end=True,
         )
 
-        """ temporary deactivate test due to 79b41f739381
         # test result reading
         self.result_reading_test(
             None,
@@ -165,7 +162,6 @@ class TestCcxTools(unittest.TestCase):
             fea=fea,
             res_obj_name=res_obj_name,
         )
-        """
 
     # ********************************************************************************************
     def test_thermomech_spine(