From 3e5c5ceccd9dab3a458d4b5e38a276caf1a8053f Mon Sep 17 00:00:00 2001
From: FEA-eng <59876896+FEA-eng@users.noreply.github.com>
Date: Mon, 8 Sep 2025 03:31:38 +0200
Subject: [PATCH] FEM: Fix the shell to shell contact example (#23533)

* FEM: Update constraint_contact_shell_shell.py

* FEM: Update constraint_contact_shell_shell.inp
---
 .../constraint_contact_shell_shell.py         | 13 +++++++----
 .../constraint_contact_shell_shell.inp        | 23 ++++++++-----------
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/Mod/Fem/femexamples/constraint_contact_shell_shell.py b/src/Mod/Fem/femexamples/constraint_contact_shell_shell.py
index 4d082c63f9..55e6bf0af6 100644
--- a/src/Mod/Fem/femexamples/constraint_contact_shell_shell.py
+++ b/src/Mod/Fem/femexamples/constraint_contact_shell_shell.py
@@ -40,7 +40,7 @@ def get_information():
         "name": "Constraint Contact Shell Shell",
         "meshtype": "face",
         "meshelement": "Tria3",
-        "constraints": ["fixed", "force", "contact"],
+        "constraints": ["displacement", "force", "contact"],
         "solvers": ["ccxtools"],
         "material": "solid",
         "equations": ["mechanical"],
@@ -171,13 +171,16 @@ def setup(doc=None, solvertype="ccxtools"):
     material_obj.Material = mat
     analysis.addObject(material_obj)
 
-    # constraint fixed
-    con_fixed = ObjectsFem.makeConstraintFixed(doc, "ConstraintFixed")
-    con_fixed.References = [
+    # constraint displacement
+    con_displacement = ObjectsFem.makeConstraintDisplacement(doc, "ConstraintDisplacement")
+    con_displacement.References = [
         (lower_tube, "Edge2"),
         (upper_tube, "Edge3"),
     ]
-    analysis.addObject(con_fixed)
+    con_displacement.xFree = False
+    con_displacement.yFree = False
+    con_displacement.zFree = False
+    analysis.addObject(con_displacement)
 
     # constraint force
     con_force = ObjectsFem.makeConstraintForce(doc, "ConstraintForce")
diff --git a/src/Mod/Fem/femtest/data/calculix/constraint_contact_shell_shell.inp b/src/Mod/Fem/femtest/data/calculix/constraint_contact_shell_shell.inp
index cb0128a2fe..357f6db849 100644
--- a/src/Mod/Fem/femtest/data/calculix/constraint_contact_shell_shell.inp
+++ b/src/Mod/Fem/femtest/data/calculix/constraint_contact_shell_shell.inp
@@ -22998,9 +22998,9 @@ Efaces
 Efaces
 
 ***********************************************************
-** constraints fixed node sets
-** ConstraintFixed
-*NSET,NSET=ConstraintFixed
+** constraints displacement node sets
+** ConstraintDisplacement
+*NSET,NSET=ConstraintDisplacement
 2,
 3,
 136,
@@ -38383,15 +38383,12 @@ DEPConstraintContact, INDConstraintContact
 
 
 ***********************************************************
-** Fixed Constraints
-** ConstraintFixed
+** Displacement constraint applied
+** ConstraintDisplacement
 *BOUNDARY
-ConstraintFixed,1
-ConstraintFixed,2
-ConstraintFixed,3
-ConstraintFixed,4
-ConstraintFixed,5
-ConstraintFixed,6
+ConstraintDisplacement,1,1,0.0
+ConstraintDisplacement,2,2,0.0
+ConstraintDisplacement,3,3,0.0
 
 
 ***********************************************************
@@ -38410,8 +38407,8 @@ U
 *EL FILE
 S, E
 ** outputs --> dat file
-** reaction forces for Constraint fixed
-*NODE PRINT, NSET=ConstraintFixed, TOTALS=ONLY
+** reaction forces for Constraint displacement constraining translation
+*NODE PRINT, NSET=ConstraintDisplacement, TOTALS=ONLY
 RF
 ** contact forces for Constraint contact
 *CONTACT PRINT, MASTER=INDConstraintContact, SLAVE=DEPConstraintContact