Attributes for a general contact interaction, such as surface properties, are specified independently of the contact domain in the Attribute Assignments portion of the interaction editor. For a brief overview of general contact, see “Understanding interactions,” Section 15.3. For a more detailed discussion, see “Surface properties for general contact,” Section 29.3.2 of the ABAQUS Analysis User's Manual. You can specify the following surface properties in a general contact interaction:
Shell/Membrane thickness assignments. Assign nondefault surface thicknesses to shell or membrane surfaces.
Shell/Membrane offset assignments. Assign the surface offset to define the distance (as a fraction of the surface thickness) from the midsurface to the reference surface.
Feature edge criteria assignments. Control the feature edges to be included in the general contact domain. Feature edges of a model include shell perimeter edges and geometric feature edges. Modeling of edge-to-edge contact is not allowed for analyses with multiple parallel domains.
To specify shell/membrane thickness assignments:
Display the general contact interaction editor using one of the following methods:
To create a new general contact interaction, follow the instructions in “Defining general contact,” Section 15.12.5.
To edit an existing general contact interaction, select Interaction
Editinteraction name from the main menu bar.
Click the Surface Properties tab in the Attribute Assignments portion of the interaction editor.
The surface thickness can be modified only for surfaces defined on shells and membranes.
Click Edit next to Shell/Membrane thickness assignments.
The Edit Shell/Membrane Thickness Assignments dialog box appears. By default, when you select a surface from the list or the table, ABAQUS/CAE highlights the surface in the viewport; however, highlighting does not apply for (Global). You can toggle off Highlight selected regions at the bottom of the dialog box to turn off selection highlighting.
Select one or more surfaces from the list of existing surfaces in the column on the left. Select (Global) to assign the shell/membrane thickness to the entire contact domain.
Click the arrows 
in the middle of the dialog box to transfer your selections to the list of shell/membrane thickness assignments.
The table on the right side of the dialog box is updated to reflect your selections.
Specify the thickness for each surface in the middle column of the Shell/Membrane Thickness Assignments table.
Enter the word ORIGINAL to set the shell/membrane thickness equal to the original shell or membrane thickness (the default);
enter the word THINNING to set the shell/membrane thickness equal to the current shell or membrane thickness; or
specify a value for the shell/membrane thickness.
Optionally, specify a scale factor for any of the shell/membrane thickness assignments in the last column of the Shell/Membrane Thickness Assignments table.
Repeat the above steps as needed to complete the shell/membrane thickness assignments. If you want to delete thickness assignments, select the rows and click Delete Selected Rows.
Note: The order of assignments may be relevant; when shell/membrane thickness assignments overlap, the last assignment will take precedence.
Click OK to save your selections and to close the Edit Shell/Membrane Thickness Assignments dialog box.
The interaction editor reappears with updated information on the number of shell/membrane thickness assignments.
Click OK to create the interaction and to close the editor.
To specify shell/membrane offset assignments:
Display the general contact interaction editor using one of the following methods:
To create a new general contact interaction, follow the instructions in “Defining general contact,” Section 15.12.5.
To edit an existing general contact interaction, select InteractionEditinteraction name from the main menu bar.
Click the Surface Properties tab in the Attribute Assignments portion of the interaction editor.
The surface offset can be modified only for surfaces defined on shells and membranes.
Click Edit next to Shell/Membrane offset assignments.
The Edit Shell/Membrane Offset Assignments dialog box appears. By default, when you select a surface from the list or the table, ABAQUS/CAE highlights the surface in the viewport; however, highlighting does not apply for (Global). You can toggle off Highlight selected regions at the bottom of the dialog box to turn off selection highlighting.
Select one or more surfaces from the list of existing surfaces in the column on the left. Select (Global) to assign the shell/membrane offset to the entire contact domain.
Click the arrows in the middle of the dialog box to transfer your selections to the list of shell/membrane offset assignments.
The table on the right side of the dialog box is updated to reflect your selections.
Specify the offset fraction for each surface in the second column of the Shell/Membrane Offset Assignments table. The offset fraction defines the distance (as a fraction of the thickness) from the midsurface to the reference surface.
Enter the word ORIGINAL to set the shell/membrane offset equal to the original shell or membrane offset (the default).
Enter SPOS to specify the top surface of the shell/membrane as the reference surface.
Enter SNEG to specify the bottom surface of the shell/membrane as the reference surface.
Specify a value between –0.5 (indicates the bottom surface of the shell/membrane) and 0.5 (indicates the top surface of the shell/membrane) for the offset fraction.
Repeat the above steps as needed to complete the shell/membrane offset assignments. If you want to delete offset assignments, select the rows and click Delete Selected Rows.
Note: The order of assignments may be relevant; when shell/membrane offset assignments overlap, the last assignment will take precedence.
Click OK to save your selections and to close the Edit Shell/Membrane Offset Assignments dialog box.
The interaction editor reappears with updated information on the number of shell/membrane offset assignments.
Click OK to create the interaction and to close the editor.
To specify feature edge criteria assignments:
Display the general contact interaction editor using one of the following methods:
To create a new general contact interaction, follow the instructions in “Defining general contact,” Section 15.12.5.
To edit an existing general contact interaction, select InteractionEditinteraction name from the main menu bar.
Click the Surface Properties tab in the Attribute Assignments portion of the interaction editor.
Click Edit next to Feature edge criteria assignments.
The Edit Feature Edge Criteria Assignments dialog box appears. By default, when you select a surface from the list or the table, ABAQUS/CAE highlights the surface in the viewport; however, highlighting does not apply for (Global). You can toggle off Highlight selected regions at the bottom of the dialog box to turn off selection highlighting.
Select one or more surfaces from the list of existing surfaces in the column on the left. Select (Global) to assign the surface feature to the entire contact domain.
Click the arrows in the middle of the dialog box to transfer your selections to the list of surface feature assignments.
The table on the right side of the dialog box is updated to reflect your selections.
Specify the feature edge criteria for each surface in the second column of the Surface Feature Assignments table.
Enter the word PERIMETER to include perimeter edges in the general contact domain (the default);
enter the word NONE to include no feature edges in the general contact domain; or
specify an angle in degrees to include perimeter edges and geometric edges with feature angles greater than or equal to the specified angle in the general contact domain. The specified value cannot be less than 20°. For examples of how the feature angle is calculated for different edges, see “Feature edges” in “Surface properties for general contact,” Section 29.3.2 of the ABAQUS Analysis User's Manual.
Repeat the above steps as needed to complete the surface feature assignments. If you want to delete surface feature assignments, select the rows and click Delete Selected Rows.
Note: The order of assignments may be relevant; when surface feature assignments overlap, the last assignment will take precedence.
Click OK to save your selections and to close the Edit Feature Edge Criteria Assignments dialog box.
The interaction editor reappears with updated information on the number of feature edge criteria assignments.
Click OK to create the interaction and to close the editor.
