diff --git a/src/Mod/Fem/FemInputWriterCcx.py b/src/Mod/Fem/FemInputWriterCcx.py
index 9f02a4583207..90da6fdd4698 100644
--- a/src/Mod/Fem/FemInputWriterCcx.py
+++ b/src/Mod/Fem/FemInputWriterCcx.py
@@ -93,28 +93,45 @@ def write_calculix_input_file(self):
         if self.contact_objects:
             self.write_constraints_contact(inpfile)
 
-        # steps and constraints dependent on steps
-        if self.analysis_type == "thermomech":
+        # step begin
+        if self.analysis_type == "frequency":
+            self.write_step_begin_static_frequency(inpfile)
+            self.write_analysis_frequency(inpfile)
+        elif self.analysis_type == "static":
+            self.write_step_begin_static_frequency(inpfile)
+        elif self.analysis_type == "thermomech":
             self.write_step_begin_thermomech(inpfile)
             self.write_analysis_thermomech(inpfile)
-        else:
-            self.write_step_begin_static_frequency(inpfile)
+
+        # constraints depend on step used in all analysis types
         if self.fixed_objects:
             self.write_constraints_fixed(inpfile)
         if self.displacement_objects:
             self.write_constraints_displacement(inpfile)
-        if self.analysis_type == "thermomech":
-            self.write_constraints_temperature(inpfile)
-            self.write_constraints_heatflux(inpfile)
-        if self.analysis_type is None or self.analysis_type == "static":
+
+        # constraints depend on step and depending on analysis type
+        if self.analysis_type == "frequency":
+            pass
+        elif self.analysis_type == "static":
             if self.selfweight_objects:
                 self.write_constraints_selfweight(inpfile)
             if self.force_objects:
                 self.write_constraints_force(inpfile)
             if self.pressure_objects:
                 self.write_constraints_pressure(inpfile)
-        elif self.analysis_type == "frequency":
-            self.write_analysis_frequency(inpfile)
+        elif self.analysis_type == "thermomech":
+            if self.selfweight_objects:
+                self.write_constraints_selfweight(inpfile)
+            if self.force_objects:
+                self.write_constraints_force(inpfile)
+            if self.pressure_objects:
+                self.write_constraints_pressure(inpfile)
+            if self.temperature_objects:
+                self.write_constraints_temperature(inpfile)
+            if self.heatflux_objects:
+                self.write_constraints_heatflux(inpfile)
+
+        # output and step end
         self.write_outputs_types(inpfile)
         self.write_step_end(inpfile)
 
@@ -301,6 +318,15 @@ def write_materials(self, f):
                 f.write('*SPECIFIC HEAT \n')
                 f.write('{0:.3e}, \n'.format(SH_in_JkgK))
 
+    def write_constraints_initialtemperature(self, f):
+        f.write('\n***********************************************************\n')
+        f.write('** Initial temperature constraint\n')
+        f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
+        f.write('*INITIAL CONDITIONS,TYPE=TEMPERATURE\n')
+        for itobj in self.initialtemperature_objects:  # Should only be one
+            inittemp_obj = itobj['Object']
+            f.write('Nall,{}\n'.format(inittemp_obj.initialTemperature))  # OvG: Initial temperature
+
     def write_femelementsets(self, f):
         f.write('\n***********************************************************\n')
         f.write('** Sections\n')
@@ -375,9 +401,37 @@ def write_step_begin_thermomech(self, f):
             f.write(self.solver_obj.IterationsControlParameterIter + '\n')
             f.write(self.solver_obj.IterationsControlParameterCutb + '\n')
 
+    def write_analysis_frequency(self, f):
+        f.write('\n***********************************************************\n')
+        f.write('** Frequency analysis\n')
+        f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
+        f.write('*FREQUENCY\n')
+        f.write('{},{},{}\n'.format(self.solver_obj.EigenmodesCount, self.solver_obj.EigenmodeLowLimit, self.solver_obj.EigenmodeHighLimit))
+
+    def write_analysis_thermomech(self, f):
+        f.write('\n***********************************************************\n')
+        f.write('** Coupled temperature displacement analysis\n')
+        f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
+        thermomech_analysis = '*COUPLED TEMPERATURE-DISPLACEMENT'
+        if self.solver_obj.MatrixSolverType == "default":
+            pass
+        elif self.solver_obj.MatrixSolverType == "spooles":
+            thermomech_analysis += ', SOLVER=SPOOLES'
+        elif self.solver_obj.MatrixSolverType == "iterativescaling":
+            thermomech_analysis += ', SOLVER=ITERATIVE SCALING'
+        elif self.solver_obj.MatrixSolverType == "iterativecholesky":
+            thermomech_analysis += ', SOLVER=ITERATIVE CHOLESKY'
+        if self.solver_obj.SteadyState:
+            thermomech_analysis += ', STEADY STATE'
+            self.solver_obj.TimeInitialStep = 1.0  # Set time to 1 and ignore user inputs for steady state
+            self.solver_obj.TimeEnd = 1.0
+        thermomech_time = '{},{}'.format(self.solver_obj.TimeInitialStep, self.solver_obj.TimeEnd)  # OvG: 1.0 increment, total time 1 for steady state will cut back automatically
+        f.write(thermomech_analysis + '\n')
+        f.write(thermomech_time + '\n')
+
     def write_constraints_fixed(self, f):
         f.write('\n***********************************************************\n')
-        f.write('** Constraints\n')
+        f.write('** Fixed Constraints\n')
         f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
         for femobj in self.fixed_objects:  # femobj --> dict, FreeCAD document object is femobj['Object']
             fix_obj_name = femobj['Object'].Name
@@ -458,19 +512,9 @@ def write_constraints_planerotation(self, f):
             f.write('*MPC\n')
             f.write('PLANE,' + fric_obj_name + '\n')
 
-    def write_constraints_temperature(self, f):
-        f.write('\n***********************************************************\n')
-        f.write('** Fixed temperature constraint applied\n')
-        f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
-        for ftobj in self.temperature_objects:
-            fixedtemp_obj = ftobj['Object']
-            f.write('*BOUNDARY\n')
-            f.write('{},11,11,{}\n'.format(fixedtemp_obj.Name, fixedtemp_obj.Temperature))
-            f.write('\n')
-
     def write_constraints_selfweight(self, f):
         f.write('\n***********************************************************\n')
-        f.write('** Self weight\n')
+        f.write('** Self weight Constraint\n')
         f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
         for femobj in self.selfweight_objects:  # femobj --> dict, FreeCAD document object is femobj['Object']
             selwei_obj_name = femobj['Object'].Name
@@ -478,15 +522,16 @@ def write_constraints_selfweight(self, f):
             f.write('*DLOAD\n')
             f.write('Eall,GRAV,9810,0,0,-1\n')
             f.write('\n')
-        # die grav (erdbeschleunigung) ist fuer alle gleich
-        # die verschidene density wurde in den material sets geschrieben !
+        # grav (erdbeschleunigung) is equal for all elements
+        # should be only one constraint
+        # different elment sets for different density are written in the material element sets allready
 
     def write_constraints_force(self, f):
         # check shape type of reference shape and get node loads
         self.get_constraints_force_nodeloads()
         # write node loads to file
         f.write('\n***********************************************************\n')
-        f.write('** Node loads\n')
+        f.write('** Node loads Constraints\n')
         f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
         f.write('*CLOAD\n')
         for femobj in self.force_objects:  # femobj --> dict, FreeCAD document object is femobj['Object']
@@ -526,6 +571,16 @@ def write_constraints_pressure(self, f):
                         for i in v:
                             f.write("{},P{},{}\n".format(i[0], i[1], rev * prs_obj.Pressure))
 
+    def write_constraints_temperature(self, f):
+        f.write('\n***********************************************************\n')
+        f.write('** Fixed temperature constraint applied\n')
+        f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
+        for ftobj in self.temperature_objects:
+            fixedtemp_obj = ftobj['Object']
+            f.write('*BOUNDARY\n')
+            f.write('{},11,11,{}\n'.format(fixedtemp_obj.Name, fixedtemp_obj.Temperature))
+            f.write('\n')
+
     def write_constraints_heatflux(self, f):
         f.write('\n***********************************************************\n')
         f.write('** Heatflux constraints\n')
@@ -542,43 +597,6 @@ def write_constraints_heatflux(self, f):
                         for i in v:
                             f.write("{},F{},{},{}\n".format(i[0], i[1], heatflux_obj.AmbientTemp, heatflux_obj.FilmCoef * 0.001))  # SvdW add factor to force heatflux to units system of t/mm/s/K # OvG: Only write out the VolumeIDs linked to a particular face
 
-    def write_analysis_frequency(self, f):
-        f.write('\n***********************************************************\n')
-        f.write('** Frequency analysis\n')
-        f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
-        f.write('*FREQUENCY\n')
-        f.write('{},{},{}\n'.format(self.solver_obj.EigenmodesCount, self.solver_obj.EigenmodeLowLimit, self.solver_obj.EigenmodeHighLimit))
-
-    def write_analysis_thermomech(self, f):
-        f.write('\n***********************************************************\n')
-        f.write('** Coupled temperature displacement analysis\n')
-        f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
-        thermomech_analysis = '*COUPLED TEMPERATURE-DISPLACEMENT'
-        if self.solver_obj.MatrixSolverType == "default":
-            pass
-        elif self.solver_obj.MatrixSolverType == "spooles":
-            thermomech_analysis += ', SOLVER=SPOOLES'
-        elif self.solver_obj.MatrixSolverType == "iterativescaling":
-            thermomech_analysis += ', SOLVER=ITERATIVE SCALING'
-        elif self.solver_obj.MatrixSolverType == "iterativecholesky":
-            thermomech_analysis += ', SOLVER=ITERATIVE CHOLESKY'
-        if self.solver_obj.SteadyState:
-            thermomech_analysis += ', STEADY STATE'
-            self.solver_obj.TimeInitialStep = 1.0  # Set time to 1 and ignore user inputs for steady state
-            self.solver_obj.TimeEnd = 1.0
-        thermomech_time = '{},{}'.format(self.solver_obj.TimeInitialStep, self.solver_obj.TimeEnd)  # OvG: 1.0 increment, total time 1 for steady state will cut back automatically
-        f.write(thermomech_analysis + '\n')
-        f.write(thermomech_time + '\n')
-
-    def write_constraints_initialtemperature(self, f):
-        f.write('\n***********************************************************\n')
-        f.write('** Initial temperature constraint\n')
-        f.write('** written by {} function\n'.format(sys._getframe().f_code.co_name))
-        f.write('*INITIAL CONDITIONS,TYPE=TEMPERATURE\n')
-        for itobj in self.initialtemperature_objects:  # Should only be one
-            inittemp_obj = itobj['Object']
-            f.write('Nall,{}\n'.format(inittemp_obj.initialTemperature))  # OvG: Initial temperature
-
     def write_outputs_types(self, f):
         f.write('\n***********************************************************\n')
         f.write('** Outputs --> frd file\n')
diff --git a/src/Mod/Fem/test_files/ccx/cube_frequency.inp b/src/Mod/Fem/test_files/ccx/cube_frequency.inp
index d73be717301f..9e129a1b61c3 100644
--- a/src/Mod/Fem/test_files/ccx/cube_frequency.inp
+++ b/src/Mod/Fem/test_files/ccx/cube_frequency.inp
@@ -488,7 +488,13 @@ Eall
 *STATIC
 
 ***********************************************************
-** Constraints
+** Frequency analysis
+** written by write_analysis_frequency function
+*FREQUENCY
+10,0.0,1000000.0
+
+***********************************************************
+** Fixed Constraints
 ** written by write_constraints_fixed function
 *BOUNDARY
 FemConstraintFixed,1
@@ -496,12 +502,6 @@ FemConstraintFixed,2
 FemConstraintFixed,3
 
 
-***********************************************************
-** Frequency analysis
-** written by write_analysis_frequency function
-*FREQUENCY
-10,0.0,1000000.0
-
 ***********************************************************
 ** Outputs --> frd file
 ** written by write_outputs_types function
diff --git a/src/Mod/Fem/test_files/ccx/cube_static.inp b/src/Mod/Fem/test_files/ccx/cube_static.inp
index da7c57152cdf..7706518e86d4 100644
--- a/src/Mod/Fem/test_files/ccx/cube_static.inp
+++ b/src/Mod/Fem/test_files/ccx/cube_static.inp
@@ -485,7 +485,7 @@ Eall
 *STATIC
 
 ***********************************************************
-** Constraints
+** Fixed Constraints
 ** written by write_constraints_fixed function
 *BOUNDARY
 FemConstraintFixed,1
@@ -494,7 +494,7 @@ FemConstraintFixed,3
 
 
 ***********************************************************
-** Node loads
+** Node loads Constraints
 ** written by write_constraints_force function
 *CLOAD
 ** FemConstraintForce
diff --git a/src/Mod/Fem/test_files/ccx/spine_thermomech.inp b/src/Mod/Fem/test_files/ccx/spine_thermomech.inp
index a72e04979832..edcec75907e1 100644
--- a/src/Mod/Fem/test_files/ccx/spine_thermomech.inp
+++ b/src/Mod/Fem/test_files/ccx/spine_thermomech.inp
@@ -137,7 +137,7 @@ Nall,300.0
 1.0,1.0
 
 ***********************************************************
-** Constraints
+** Fixed Constraints
 ** written by write_constraints_fixed function
 *BOUNDARY
 FemConstraintFixed,1