Fem: Add support for 2D geometries to Tie constraint - fixes #13280

src/Mod/Fem/femmesh/meshsetsgetter.py

@@ -474,16 +474,15 @@ class MeshSetsGetter:
 
         for femobj in self.member.cons_tie:
             # 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"]))
+            obj = femobj["Object"]
+            print_obj_info(obj)
+            result = []
+            ref_data = meshtools.pair_obj_reference(obj.References)
+            for ref_pair in ref_data:
+                result.append(meshtools.get_ccx_elements(self, ref_pair))
+
+            femobj["TieSlaveFaces"] = result[:-1]
+            femobj["TieMasterFaces"] = result[-1:]
 
     def get_constraints_sectionprint_faces(self):
         if not self.member.cons_sectionprint:

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

@@ -60,12 +60,23 @@ def get_after_write_constraint():
 def write_meshdata_constraint(f, femobj, tie_obj, ccxwriter):
     # slave DEP
     f.write(f"*SURFACE, NAME=TIE_DEP{tie_obj.Name}\n")
-    for i in femobj["TieSlaveFaces"]:
-        f.write(f"{i[0]},S{i[1]}\n")
+    for refs, surf, is_sub_el in femobj["TieSlaveFaces"]:
+        if is_sub_el:
+            for elem, fno in surf:
+                f.write(f"{elem},S{fno}\n")
+        else:
+            for elem in surf:
+                f.write(f"{elem},S2\n")
+
     # master IND
     f.write(f"*SURFACE, NAME=TIE_IND{tie_obj.Name}\n")
-    for i in femobj["TieMasterFaces"]:
-        f.write(f"{i[0]},S{i[1]}\n")
+    for refs, surf, is_sub_el in femobj["TieMasterFaces"]:
+        if is_sub_el:
+            for elem, fno in surf:
+                f.write(f"{elem},S{fno}\n")
+        else:
+            for elem in surf:
+                f.write(f"{elem},S2\n")
 
 
 def write_constraint(f, femobj, tie_obj, ccxwriter):

src/Mod/Fem/femtaskpanels/task_constraint_tie.py

@@ -63,7 +63,7 @@ class _TaskPanel(base_femtaskpanel._BaseTaskPanel):
 
         # geometry selection widget
         self.selectionWidget = selection_widgets.GeometryElementsSelection(
-            obj.References, ["Face"], False, False
+            obj.References, ["Edge", "Face"], False, False
         )
 
         # form made from param and selection widget