Product: ABAQUS/Standard
| GAPUNI | Unidirectional gap between two nodes |
| GAPCYL | Cylindrical gap between two nodes |
| GAPSPHER | Spherical gap between two nodes |
For DGAP elements, and for GAPUNI and GAPUNIT if you specify the contact direction 
, the nodal coordinates are not used in the contact calculations; however, it is useful to define the coordinates of the two nodes for plotting purposes.
GAPCYL and GAPSPHER: 
, 
, 
You can specify the initial clearance, the contact direction (normal to the interface), and the contact area.
For GAPUNI, GAPUNIT, and DGAP elements, a negative clearance indicates an initial overclosure.
For GAPCYL and GAPSPHER elements, specify the maximum separation as a positive number or the minimum separation as a negative number.
| Input File Usage: | *GAP |
S11 | Pressure transmitted between the surfaces. The pressure is defined as the force divided by the user-specified area. |
S12 | First frictional shear stress normal to the gap direction. |
S13 | Second frictional shear stress normal to the gap direction. |
E11 | Current opening |
E12 | Relative displacement (“slip”) in the first direction orthogonal to the contact direction. |
E13 | Relative displacement (“slip”) in the second direction orthogonal to the contact direction. |
Available for elements with temperature degrees of freedom.
HFL1 | Heat flux across the interface in the contact direction. |
The increments of shear slip are the relative displacement increments projected onto the two local directions that are orthogonal to the contact direction.
In two-dimensional or axisymmetric models when the contact direction is along the first axis ( or 
), the active slip direction is E13 and the active shear stress is S13. In any other two-dimensional or axisymmetric case, the active slip direction is E12 and the active shear stress is S12.
of the gap element.