Fem: Add support for cyclic symmetry - fixes FreeCAD#12155

Author: marioalexis84

src/Mod/Fem/femobjects/base_fempythonobject.py

@@ -47,3 +47,19 @@ def dumps(self):
 
     def loads(self, state):
         return None
+
+
+class _PropHelper:
+    """
+    Helper class to manage property data inside proxy objects.
+    Initialization keywords are the same used with PropertyContainer
+    to add dynamics properties plus "value" for the initial value.
+    """
+    def __init__(self, **kwds):
+        self.value = kwds.pop("value")
+        self.info = kwds
+        self.name = kwds["name"]
+
+    def add_to_object(self, obj):
+        obj.addProperty(**self.info)
+        setattr(obj, self.name, self.value)

src/Mod/Fem/femobjects/constraint_tie.py

@@ -31,6 +31,10 @@
 
 from . import base_fempythonobject
 
+import FreeCAD
+
+_PropHelper = base_fempythonobject._PropHelper
+
 
 class ConstraintTie(base_fempythonobject.BaseFemPythonObject):
     """
@@ -42,18 +46,68 @@ class ConstraintTie(base_fempythonobject.BaseFemPythonObject):
     def __init__(self, obj):
         super(ConstraintTie, self).__init__(obj)
 
-        obj.addProperty(
-            "App::PropertyLength",
-            "Tolerance",
-            "Geometry",
-            "Set max gap between tied faces"
-        )
-        obj.Tolerance = "0.0 mm"
+        for prop in self._get_properties():
+            prop.add_to_object(obj)
 
-        obj.addProperty(
-            "App::PropertyBool",
-            "Adjust",
-            "Geometry",
-            "Adjust connected nodes"
+    def _get_properties(self):
+        prop = []
+
+        prop.append(_PropHelper(
+            type  = "App::PropertyLength",
+            name  = "Tolerance",
+            group = "Geometry",
+            doc   = "Set max gap between tied faces",
+            value = "0.0 mm"
+            )
+        )
+        prop.append(_PropHelper(
+            type  = "App::PropertyBool",
+            name  = "Adjust",
+            group = "Geometry",
+            doc   = "Adjust connected nodes",
+            value = False
+            )
+        )
+        prop.append(_PropHelper(
+            type  = "App::PropertyBool",
+            name  = "CyclicSymmetry",
+            group = "Geometry",
+            doc   = "Define cyclic symmetry model",
+            value = False
+            )
         )
-        obj.Adjust = False
+        prop.append(_PropHelper(
+            type  = "App::PropertyPlacement",
+            name  = "SymmetryAxis",
+            group = "Geometry",
+            doc   = "Placement of axis of symmetry",
+            value = FreeCAD.Placement()
+            )
+        )
+        prop.append(_PropHelper(
+            type  = "App::PropertyInteger",
+            name  = "Sectors",
+            group = "Geometry",
+            doc   = "Number of sectors",
+            value = 0
+            )
+        )
+        prop.append(_PropHelper(
+            type  = "App::PropertyInteger",
+            name  = "ConnectedSectors",
+            group = "Geometry",
+            doc   = "Number of connected sectors",
+            value = 1
+            )
+        )
+
+        return prop
+
+
+    def onDocumentRestored(self, obj):
+        # update old proyect with new properties
+        for prop in self._get_properties():
+            try:
+                obj.getPropertyByName(prop.name)
+            except:
+                prop.add_to_object(obj)

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

@@ -26,6 +26,9 @@
 __url__ = "https://www.freecad.org"
 
 
+from FreeCAD import Units, Vector
+
+
 def get_analysis_types():
     return "all"    # write for all analysis types
 
@@ -71,12 +74,38 @@ def write_constraint(f, femobj, tie_obj, ccxwriter):
 
     tolerance = tie_obj.Tolerance.getValueAs("mm").Value
     adjust = ""
+    symmetry = ""
+    tie_name = tie_obj.Name
     if not tie_obj.Adjust:
         adjust = ", ADJUST=NO"
+
+    if tie_obj.CyclicSymmetry:
+        symmetry = ", CYCLIC SYMMETRY"
+
     f.write(
-        "*TIE, POSITION TOLERANCE={:.13G}{}, NAME=TIE{}\n"
-        .format(tolerance, adjust, tie_obj.Name)
+        "*TIE, POSITION TOLERANCE={:.13G}{}{}, NAME=TIE{}\n"
+        .format(tolerance, adjust, symmetry, tie_name)
     )
-    ind_surf = "TIE_IND{}".format(tie_obj.Name)
-    dep_surf = "TIE_DEP{}".format(tie_obj.Name)
+    ind_surf = "TIE_IND{}".format(tie_name)
+    dep_surf = "TIE_DEP{}".format(tie_name)
     f.write("{}, {}\n".format(dep_surf, ind_surf))
+
+    # write CYCLIC SYMMETRY MODEL card
+    if tie_obj.CyclicSymmetry:
+        f.write(
+            "*CYCLIC SYMMETRY MODEL, N={}, NGRAPH={}, TIE=TIE{}, ELSET=Eall\n"
+            .format(tie_obj.Sectors, tie_obj.ConnectedSectors, tie_name)
+        )
+
+        # get symmetry axis points
+        vec_a = tie_obj.SymmetryAxis.Base
+        vec_b = tie_obj.SymmetryAxis * Vector(0, 0, 1)
+
+        set_unit = lambda x: Units.Quantity(x, Units.Length).getValueAs("mm").Value
+        point_a = [set_unit(coord) for coord in vec_a]
+        point_b = [set_unit(coord) for coord in vec_b]
+
+        f.write(
+            "{:.13G},{:.13G},{:.13G},{:.13G},{:.13G},{:.13G}\n"
+            .format(*point_a, *point_b)
+        )