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Mortar contact is a consistently weak formulation of the contact conditions. For
details of the method the reader is referred to [28] and
[25]. It is a surface-to-surface method which usually leads to
better convergence and a more uniform stress field. In the author's experience
the iterations take longer (higher computational effort), however, fewer are
needed to obtain convergence. The contact definition in
the input deck is similar to penalty contact except for:
- The contact surfaces (both slave and master) must be face-based.
- On the *CONTACT PAIR card the parameter
TYPE=SURFACE TO SURFACE must be specified to trigger Mortar contact (default
is penalty contact).
- The SMALL SLIDING parameter on the *CONTACT PAIR card has no effect. The
Mortar implementation is such that the pairing of the slave and master
surface and the calculation of the normals to the slave surface is done at
the start of each new increment. It is not repeated for each iteration.
- The *SURFACE BEHAVIOR card needs only one parameter: the spring
constant.
- The *FRICTION card is needed to specify the friction coefficient. The
stick slope is irrelevant since the stick range for the present Mortar
formulation is zero (infinite stick slope).
Next: Materials
Up: Boundary conditions
Previous: Penalty Contact
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guido dhondt
2013-08-06