ABAQUS Keywords Reference Manual  

*SURFACE INTERACTION
Define surface interaction properties.

This option is used to create a surface interaction property definition. The surface interaction properties will govern any contact interactions that reference this surface interaction.

Products: ABAQUS/Standard  ABAQUS/Explicit  

Type: Model data in ABAQUS/Standard; Model or history data in ABAQUS/Explicit

Level: Model in ABAQUS/Standard; Model or Step in ABAQUS/Explicit  

References:

Required parameter:

NAME

Set this parameter equal to the name of this surface interaction property definition.

Use this name on the INTERACTION parameter of the *CONTACT PAIR option (for an ABAQUS/Standard contact analysis or an ABAQUS/Explicit analysis using the contact pair algorithm) or on the data line of the *CONTACT PROPERTY ASSIGNMENT option (for an ABAQUS/Explicit analysis using the general contact algorithm) to assign this surface interaction property to a contact interaction.

Optional parameters:

PAD THICKNESS

This parameter applies only to ABAQUS/Explicit analyses using the contact pair algorithm.

Set this parameter equal to the thickness of an interfacial layer between the contacting surfaces. The value can be positive or negative.

USER

Include this parameter if the surface interaction model is to be defined in user subroutine UINTER in an ABAQUS/Standard analysis or in user subroutine VUINTER in an ABAQUS/Explicit analysis. When this parameter is included, the *SURFACE BEHAVIOR option and its various suboptions cannot be used under the same interaction definition.

Optional parameters if the USER parameter is used: 

DEPVAR

Set DEPVAR equal to the number of state-dependent variables required for user subroutine UINTER in an ABAQUS/Standard analysis or for user subroutine VUINTER in an ABAQUS/Explicit analysis. The default is DEPVAR=0.

PROPERTIES

Set this parameter equal to the number of property values needed as data to define the surface interaction model in user subroutine UINTER in an ABAQUS/Standard analysis or in user subroutine VUINTER in an ABAQUS/Explicit analysis. The default is PROPERTIES=0. This parameter is ignored when the option is used in association with a connector element.

UNSYMM

This parameter applies only to ABAQUS/Standard analyses.

Include this parameter when the interface stiffness matrix is not symmetric. This parameter causes ABAQUS/Standard to use its unsymmetric equation solution procedures.

Optional data line for two-dimensional models in ABAQUS/Standard or for contact pairs involving node-based surfaces in ABAQUS/Standard, if the USER parameter is omitted: 

First (and only) line:

  1. Out-of-plane thickness of the surface or cross-sectional area for every node in the node-based surface. The default value is 1.0.

Data lines to define the surface interaction in an ABAQUS/Standard analysis if the USER parameter is used: 

First line:

  1. Out-of-plane thickness of the surface for two-dimensional models or cross-sectional area for every node in the node-based surface. The default value for both is 1.0. In other situations, enter a blank line.

Second line (needed only if the PROPERTIES parameter is used):

  1. Enter the values of the surface interaction properties, eight per line.

Repeat this data line as often as necessary to define all material constants.

Data lines to define the surface interaction in an ABAQUS/Explicit analysis if the PROPERTIES parameter is used: 

First line:

  1. Enter a blank line.

Second line:

  1. Enter the values of the surface interaction properties, eight per line.

Repeat this data line as often as necessary to define all material constants.