FEM: constraint tie, get the faces data in writer base class

src/Mod/Fem/femmesh/meshtools.py

@@ -1737,6 +1737,81 @@ def get_contact_obj_faces(
     return [slave_faces, master_faces]
 
 
+# ***** tie faces ****************************************************************************
+def get_tie_obj_faces(
+    femmesh,
+    femelement_table,
+    femnodes_ele_table,
+    femobj
+):
+    # see comment get_contact_obj_faces
+    # solid mesh is same as contact, but face mesh is not allowed for tie
+    # TODO get rid of duplicate code for contact and tie
+
+    slave_faces, master_faces = [], []
+
+    tie_obj = femobj["Object"]
+    if len(tie_obj.References) == 1 and len(tie_obj.References[0][1]) == 2:
+        # [(<Part::PartFeature>, ('Face7', 'Face3'))]
+        # refs are merged because they are on the same doc obj
+        # but only one element face for each contact face (Gui, TaskPael tie)
+        ref_obj = tie_obj.References[0][0]
+        ref_ele = tie_obj.References[0][1]
+        slave_ref = (ref_obj, (ref_ele[0],))  # the comma is needed!
+        master_ref = (ref_obj, (ref_ele[1],))  # the comma is needed!
+    elif (
+        len(tie_obj.References) == 2
+        and len(tie_obj.References[0][1]) == 1
+        and len(tie_obj.References[1][1]) == 1
+    ):
+        # [(<Part::PartFeature>, ('Face3',)), (<Part::PartFeature>, ('Face7',))]
+        # refs are on different objects
+        # but only one element face for each contact face (Gui, TaskPael tie)
+        slave_ref = tie_obj.References[0]
+        master_ref = tie_obj.References[1]
+    else:
+        FreeCAD.Console.PrintError(
+            "Not valid (example: only master or slave defined) "
+            "or not supported reference shape elements, contact face combination "
+            "(example: multiple element faces per master or slave\n"
+        )
+
+    FreeCAD.Console.PrintLog("Slave: {}, {}\n".format(slave_ref[0].Name, slave_ref))
+    FreeCAD.Console.PrintLog("Master: {}, {}\n".format(master_ref[0].Name, master_ref))
+
+    if is_solid_femmesh(femmesh):
+        # get the nodes, sorted and duplicates removed
+        slaveface_nds = sorted(list(set(get_femnodes_by_refshape(femmesh, slave_ref))))
+        masterface_nds = sorted(list(set(get_femnodes_by_refshape(femmesh, master_ref))))
+        # FreeCAD.Console.PrintLog("slaveface_nds: {}\n".format(slaveface_nds))
+        # FreeCAD.Console.PrintLog("masterface_nds: {}\n".format(slaveface_nds))
+
+        # fill the bit_pattern_dict and search for the faces
+        slave_bit_pattern_dict = get_bit_pattern_dict(
+            femelement_table,
+            femnodes_ele_table,
+            slaveface_nds
+        )
+        master_bit_pattern_dict = get_bit_pattern_dict(
+            femelement_table,
+            femnodes_ele_table,
+            masterface_nds
+        )
+
+        # get the faces ids
+        slave_faces = get_ccxelement_faces_from_binary_search(slave_bit_pattern_dict)
+        master_faces = get_ccxelement_faces_from_binary_search(master_bit_pattern_dict)
+
+    elif is_face_femmesh(femmesh):
+        FreeCAD.Console.PrintError(
+            "Shell mesh is not allowed for constraint tie.\n"
+        )
+
+    FreeCAD.Console.PrintLog("slave_faces: {}\n".format(slave_faces))
+    FreeCAD.Console.PrintLog("master_faces: {}\n".format(master_faces))
+    return [slave_faces, master_faces]
+
+
 # ************************************************************************************************
 # ***** groups ***********************************************************************************
 def get_mesh_group_elements(

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

@@ -625,44 +625,24 @@ def write_surfaces_constraints_contact(self, f):
                 f.write("{},S{}\n".format(i[0], i[1]))
 
     def write_surfaces_constraints_tie(self, f):
-        # get surface nodes and write them to file
+        # get faces
+        self.get_constraints_tie_faces()
+        # write faces to file
         f.write("\n***********************************************************\n")
         f.write("** Surfaces for tie constraint\n")
         f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-        obj = 0
         for femobj in self.tie_objects:
             # femobj --> dict, FreeCAD document object is femobj["Object"]
             tie_obj = femobj["Object"]
             f.write("** " + tie_obj.Label + "\n")
-            cnt = 0
-            obj = obj + 1
-            for o, elem_tup in tie_obj.References:
-                for elem in elem_tup:
-                    ref_shape = o.Shape.getElement(elem)
-                    cnt = cnt + 1
-                    if ref_shape.ShapeType == "Face":
-                        if cnt == 1:
-                            name = "TIE_DEP" + str(obj)
-                        else:
-                            name = "TIE_IND" + str(obj)
-                        f.write("*SURFACE, NAME=" + name + "\n")
-
-                        v = self.mesh_object.FemMesh.getccxVolumesByFace(ref_shape)
-                        if len(v) > 0:
-                            # volume elements found
-                            FreeCAD.Console.PrintLog(
-                                "{}, surface {}, {} touching volume elements found\n"
-                                .format(tie_obj.Label, name, len(v))
-                            )
-                            for i in v:
-                                f.write("{},S{}\n".format(i[0], i[1]))
-                        else:
-                            # no volume elements found, shell elements not allowed
-                            FreeCAD.Console.PrintError(
-                                "{}, surface {}, Error: "
-                                "No volume elements found!\n"
-                                .format(tie_obj.Label, name)
-                            )
+            # slave DEP
+            f.write("*SURFACE, NAME=TIE_DEP{}\n".format(tie_obj.Name))
+            for i in femobj["TieSlaveFaces"]:
+                f.write("{},S{}\n".format(i[0], i[1]))
+            # master IND
+            f.write("*SURFACE, NAME=TIE_IND{}\n".format(tie_obj.Name))
+            for i in femobj["TieMasterFaces"]:
+                f.write("{},S{}\n".format(i[0], i[1]))
 
     def write_node_sets_constraints_transform(self, f):
         # get nodes
@@ -1098,19 +1078,17 @@ def write_constraints_tie(self, f):
         f.write("\n***********************************************************\n")
         f.write("** Tie Constraints\n")
         f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-        obj = 0
         for femobj in self.tie_objects:
             # femobj --> dict, FreeCAD document object is femobj["Object"]
-            obj = obj + 1
             tie_obj = femobj["Object"]
             f.write("** {}\n".format(tie_obj.Label))
             tolerance = str(tie_obj.Tolerance.getValueAs("mm")).rstrip()
             f.write(
                 "*TIE, POSITION TOLERANCE={}, ADJUST=NO, NAME=TIE{}\n"
-                .format(tolerance, obj)
+                .format(tolerance, tie_obj.Name)
             )
-            ind_surf = "TIE_IND" + str(obj)
-            dep_surf = "TIE_DEP" + str(obj)
+            ind_surf = "TIE_IND" + tie_obj.Name
+            dep_surf = "TIE_DEP" + tie_obj.Name
             f.write("{},{}\n".format(dep_surf, ind_surf))
 
     def write_constraints_planerotation(self, f):

src/Mod/Fem/femsolver/writerbase.py

@@ -352,6 +352,32 @@ def get_constraints_contact_faces(self):
             # FreeCAD.Console.PrintLog("{}\n".format(femobj["ContactSlaveFaces"]))
             # FreeCAD.Console.PrintLog("{}\n".format(femobj["ContactMasterFaces"]))
 
+    def get_constraints_tie_faces(self):
+        if not self.femnodes_mesh:
+            self.femnodes_mesh = self.femmesh.Nodes
+        if not self.femelement_table:
+            self.femelement_table = meshtools.get_femelement_table(self.femmesh)
+        if not self.femnodes_ele_table:
+            self.femnodes_ele_table = meshtools.get_femnodes_ele_table(
+                self.femnodes_mesh,
+                self.femelement_table
+            )
+
+        for femobj in self.tie_objects:
+            # femobj --> dict, FreeCAD document object is femobj["Object"]
+            print_obj_info(femobj["Object"])
+            slave_faces, master_faces = meshtools.get_tie_obj_faces(
+                self.femmesh,
+                self.femelement_table,
+                self.femnodes_ele_table, femobj
+            )
+            # [ele_id, ele_face_id], [ele_id, ele_face_id], ...]
+            # whereas the ele_face_id might be ccx specific
+            femobj["TieSlaveFaces"] = slave_faces
+            femobj["TieMasterFaces"] = master_faces
+            # FreeCAD.Console.PrintLog("{}\n".format(femobj["ContactSlaveFaces"]))
+            # FreeCAD.Console.PrintLog("{}\n".format(femobj["ContactMasterFaces"]))
+
     def get_element_geometry2D_elements(self):
         # get element ids and write them into the objects
         FreeCAD.Console.PrintMessage("Shell thicknesses\n")

src/Mod/Fem/femtest/data/ccx/constraint_tie.inp

@@ -18547,7 +18547,7 @@ Evolumes
 ** Surfaces for tie constraint
 ** written by write_surfaces_constraints_tie function
 ** ConstraintTie
-*SURFACE, NAME=TIE_DEP1
+*SURFACE, NAME=TIE_DEPConstraintTie
 4834,S1
 4835,S1
 4890,S1
@@ -18570,7 +18570,7 @@ Evolumes
 9637,S1
 9877,S1
 10493,S2
-*SURFACE, NAME=TIE_IND1
+*SURFACE, NAME=TIE_INDConstraintTie
 4687,S4
 5445,S3
 5759,S4
@@ -18613,8 +18613,8 @@ Evolumes
 ** Tie Constraints
 ** written by write_constraints_tie function
 ** ConstraintTie
-*TIE, POSITION TOLERANCE=25, ADJUST=NO, NAME=TIE1
-TIE_DEP1,TIE_IND1
+*TIE, POSITION TOLERANCE=25, ADJUST=NO, NAME=TIEConstraintTie
+TIE_DEPConstraintTie,TIE_INDConstraintTie
 
 ***********************************************************
 ** At least one step is needed to run an CalculiX analysis of FreeCAD
@@ -18665,8 +18665,8 @@ RF
 ***********************************************************
 ** CalculiX Input file
 ** written by write_footer function
-**   written by    --> FreeCAD 0.19.19475 (Git)
-**   written on    --> Tue Feb  4 16:49:27 2020
+**   written by    --> FreeCAD 0.19.19481 (Git)
+**   written on    --> Wed Feb  5 08:55:37 2020
 **   file name     --> 
 **   analysis name --> Analysis
 **