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How is the penalty factor used in the penalty method?
Posted 16 nov. 2012, 16:13 UTC−5 Structural Mechanics Version 3.5a 1 Reply
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I am modeling a transient contact problem using the penalty method instead of the augmented Lagrangian method. How does COMSOL use the penalty factor when the penalty method is being used? I understand how it is used in the augmented Lagrangian method. This is described very nicely in the Structural Mechanics User's Guide. The penalty method is not described at all. Any help would be greatly appreciated!
Ryan
Ryan
1 Reply Last Post 19 nov. 2012, 07:24 UTC−5
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Posted:
1 decade ago
Hi Ryan,
There is good COMSOL documentation on the penalty contact method in the “Contact Analysis of a Snap Hook Using a Penalty Formulation” page. I don’t know if this page dates back to v3.5A. That page also gives the pros and cons of the penalty method compared to the Augmented Lagrangian method.
Penalty contact adds stiff springs (penalty factor) between the contacting surfaces that are only active when the surfaces overlap. The higher the penalty factor the less the overlap between the surfaces (and hence more accurate solution) yet the more ill-conditioned the stiffness matrix will be.
Nagi Elabbasi
Veryst Engineering
There is good COMSOL documentation on the penalty contact method in the “Contact Analysis of a Snap Hook Using a Penalty Formulation” page. I don’t know if this page dates back to v3.5A. That page also gives the pros and cons of the penalty method compared to the Augmented Lagrangian method.
Penalty contact adds stiff springs (penalty factor) between the contacting surfaces that are only active when the surfaces overlap. The higher the penalty factor the less the overlap between the surfaces (and hence more accurate solution) yet the more ill-conditioned the stiffness matrix will be.
Nagi Elabbasi
Veryst Engineering