Workbench Mechanical - Introduction to Contact

Workbench Mechanical - Introduction to Contact
… Comparison of Formulations
Training Manual
• The table below summarizes some pros (+) and cons (-) with different
contact formulations:
+
-
-
+
+
+
+
Pure Penalty
Good convergence
behavior (few
equilibrium iterations)
Sensitive to selection of
normal contact stiffness
Contact penetration is
present and
uncontrolled
Useful for any type of
contact behavior
Either Iterative or Direct
Solvers can be used
Symmetric or
asymmetric contact
available
Contact detection at
integration points
Augmented Lagrange
May require additional
- equilibrium iterations if
penetration is too large
Less sensitive to
selection of normal
contact stiffness
Contact penetration is
present but controlled to
some degree
Useful for any type of
+
contact behavior
Either Iterative or Direct
+
Solvers can be used
Symmetric or
+ asymmetric contact
available
Contact detection at
+
integration points
-
+
+
+
-
Normal Lagrange
May require additional
equilibrium iterations if +
chattering is present
No normal contact
stiffness is required +
Usually, penetration is
near-zero +
Useful for any type of
contact behavior
Only Direct Solver can
be used
Asymmetric contact
only
Contact detection at
nodes
-
+
MPC
Good convergence
behavior (few
equilibrium iterations)
No normal contact
stiffness is required
No penetration
Only Bonded & No
Separation behaviors
Either Iterative or Direct
Solvers can be used
Asymmetric contact
only
Contact detection at
nodes
– Note that some topics, such as symmetric contact or contact detection, will be discussed
shortly
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April 30, 2009
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