tied-facet-on-facet¶
Module: solid
Category: surfaceinteraction
Type string: "tied-facet-on-facet"
Parameters¶
| Name | Description | Default | Units |
|---|---|---|---|
laugon |
Enforcement method | 0 | [] |
tolerance |
tolerance | 0.01 | [] |
penalty |
penalty | 1 | [] |
minaug |
minaug | 0 | [] |
maxaug |
maxaug | 10 | [] |
search_tolerance |
search_tolerance | 0.0001 | [] |
gap_offset |
gap_offset | false | [] |
Description¶
A tied-facet-on-facet contact interface can be used for tying the surfaces of two solid parts. It enforces continuity of the displacement across the interface. This formulation is inherently symmetric.
contact enforcement¶
Like most contact formulations in FEBio, the contact constraint for this formulation is enforced using the augmented Lagrangian method (ALM).
The following parameters affect the ALM.
-
laugon: this enables or disables the AML. When disabled, a standard penalty method is used. -
penalty: the penalty factor used to enforce the constraint. -
tolerance: the tolerance on the approximate Lagrange multiplier norm and used as a termination criterion for the augmentations. -
minaug: sets the minimum number of augmentations that will be done when augmentations are enabled (i.e.laugonis 1). -
maxaug: sets the maximum number of augmentations that will be done when augmentations are enabled.
contact projection¶
The formulation identifies contact pairs by using a closest point projection method. For each integration point on the primary surface, the closest point on the secondary surface is found . There are several parameters that influence how the projection works.
-
search_tol: this sets the tolerance on the search for finding the isoparametric coordinates of the projected point onto a secondary surface facet. -
gap_offset: specifies an additional offset that is taken into account when calculating the contact gap.