*SURFACE INTERACTION

Products Abaqus/Standard Abaqus/Explicit Abaqus/CAE

Type Model data in Abaqus/Standard; Model or history data in Abaqus/Explicit

LevelModel in Abaqus/Standard; Model or Step in Abaqus/Explicit

Abaqus/CAE Interaction module

Required parameters

NAME

Set this parameter equal to a label that will be used to refer to this surface interaction property.

Use this label 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

DEPVAR

This parameter is relevant only when the USER parameter is included.

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 or VUINTERACTION in an Abaqus/Explicit analysis. The default is DEPVAR=0.

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.

PROPERTIES

This parameter is relevant only when the USER parameter is included.

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 or VUINTERACTION 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.

RATE FACTOR

This parameter applies only to Abaqus/Explicit analyses using general contact in conjunction with rate-dependent surface-based cohesive damage or rate-dependent friction behavior.

Set this parameter equal to the factor $ω$ in the equation that is used to filter the rate of separation or rate of slip (see Filtering Rates of Relative Motion). The default value is 0.9.

RATE INTERPOLATION

This parameter applies only to Abaqus/Explicit analyses using general contact and influences the interpolation of friction coefficients and cohesive damage parameters with respect to the slip rate and rate of separation.

Set RATE INTERPOLATION=LOGARITHMIC (default) to use logarithmic interpolation with respect to slip rate and rate of separation dependencies.

Set RATE INTERPOLATION=LINEAR to use linear interpolation with respect to slip rate and rate of separation dependencies.

TRACKING THICKNESS

Set this parameter equal to the thickness that determines the contacting surfaces to be tracked.

In Abaqus/Standard and Abaqus/Explicit the tracking range will be at least as large as the setting of this parameter; an internally computed default will remain in effect if this parameter setting is less than the default. This parameter extends the range over which contact opening distance (COPEN) output is provided for separated surfaces.

In Abaqus/Explicit this parameter also applies if user subroutine VUINTER or VUINTERACTION is in effect. Only contacting surfaces whose proximity is within this thickness are available for user-defined interactions. This parameter affects only node-to-surface contact, and the input value for this parameter cannot be negative. An internal default value is used if a zero value is input or if the parameter is omitted.

UNSYMM

This parameter applies only to Abaqus/Standard analyses in which the USER parameter is included.

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

USER

In an Abaqus/Standard analysis, include this parameter if the surface interaction model is to be defined in user subroutine UINTER

In an Abaqus/Explicit analysis, include this parameter without any assignment if the surface interaction model is to be defined in user subroutine VUINTER. Set USER=INTERACTION if the surface interaction model is to be defined in user subroutine VUINTERACTION. VUINTER is applicable to contact pairs, whereas VUINTERACTION is applicable to general contact.

When this parameter is included, the SURFACE BEHAVIOR option and its various suboptions cannot be used under the same interaction definition.

UXFEMCRACK

This parameter applies only to Abaqus/Standard analyses.

Include this parameter if the surface interaction between the cracked element surfaces for enriched elements using a small-sliding formulation is to be defined in user subroutine UXFEMCRACK.

Optional data line if both the USER and the UXFEMCRACK parameters are omitted for two-dimensional models in Abaqus/Standard or for contact pairs involving node-based surfaces in Abaqus/Standard

First (and only) line

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. Abaqus/Standard uses this value to compute the contact nodal areas and contact stresses.

Data lines to define the surface interaction in an Abaqus/Standard analysis if the USER or the UXFEMCRACK parameter is used

First line

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)

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

Enter a blank line.

Second line

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

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