Surface-based Contact Options

The tables below describe data required to define a surface-based contact interaction.

The only option available in a thermal simulation step is the Contact property.

This page discusses:

General Options


Tie surfaces	Within specified tolerance: Surfaces in this contact interaction will be tied together for the duration of the simulation; that is, no relative motion between the surfaces will occur at contacting interfaces. If this option is not selected, the default behavior is small sliding, which assumes that although two bodies might undergo large motions, there will be relatively little sliding of one surface along the other. You can accept the Default tolerance to tie surface pairs that are within this distance of each other. Surface pairs farther away from each other will not be tied. The default tolerance value is (0.05) x (the characteristic element length). You can enter a different value for the tolerance distance if desired. Compute tolerance from geometry: Surfaces in this contact interaction will always be tied together, regardless of the separation distance. (A sufficiently large tolerance is automatically computed and used in the Abaqus solvers.)

The following options are available for surface-based contact in steps other than explicit dynamic.


Specify initial clearance (only for Use small-sliding approximation)	An initial clearance imposes an artificial uniform distance between two surfaces in surface-based contact. The specified clearance overrides the separation distance determined by the spatial coordinates of the surfaces and is used in all contact calculations for the simulation.
Critical penetration (only for Use small-sliding approximation or Node-to-Surface discretization)	Distance by which a point on the secondary surface must penetrate the main surface before the Abaqus solvers abandons the current increment and tries again with a smaller increment.
Extension zone (only for Node-to-Surface discretization)	Fraction of the end segment or facet edge length by which the main surface is to be extended to avoid numerical roundoff errors associated with contact modeling. This value must be between 0.0 and 0.2.


Make strain-free adjustments	Move regions of the secondary surface within a specified adjustment zone so that they precisely contact the main surface; the adjustments do not create any strain in the model. You can choose the tolerance within which secondary surfaces will be adjusted by changing the Gap capture zone.
Resolve overclosures during analysis	Do not adjust any secondary surfaces before the analysis starts.
Capture offsets	Prevent the overclosed nodes on the secondary surface from being moved (adjusted) back to the main surface. Record the offset distances for the underclosed secondary surface nodes and act as if they are in contact during the simulation.
Gap capture zone	Depth of the adjustment zone, as measured from the main surface.