To define a tie constraint:

From the main menu bar, select ConstraintCreate.

Tip:  You can also create a tie constraint using the tool in the Interaction module toolbox.

In the Create Constraint dialog box that appears, do the following:

Name the constraint. For more information about naming objects, see “Using basic dialog box components,” Section 3.2.1.

From the Type list, select Tie, then click Continue.

Use one of the following methods to select the master surface:

Use an existing surface to define the region. On the right side of the prompt area, click Surfaces. Select an existing surface from the Region Selection dialog box that appears, and click Continue.

Note:  The default selection method is based on the selection method you most recently employed. To revert to the other method, click Select in Viewport or Surfaces on the right side of the prompt area.

Use the mouse to select a region in the viewport. (For more information, see “Selecting objects within the current viewport,” Section 6.2.) Click mouse button 2 to indicate that you have finished selecting. You must select a region from only one part instance; the region that you select cannot span multiple part instances.

If the model contains a combination of orphan mesh instances and native geometric part instances, click one of the following from the prompt area:

• Click Geometry if you want to select the surface or vertex from a native geometric part instance.

• Click Mesh if you want to select the surface or node from an orphan mesh instance.

You can use the angle method to select a group of faces or edges from a native geometric part instance or a group of element faces from an orphan mesh part instance. For more information, see “Using the angle method to select multiple objects,” Section 6.2.3.

The master surface that you select becomes highlighted in red in the viewport.

Select the slave surface.

In the prompt area, click the arrow next to the text field and select one of the following:

Select Surface if you want to select a surface.

Select Node Region if you want to select a region from which to create a node-based surface.

Use one of the same methods described in the previous step to select the slave surface or region. As with the master surface, the surface or region that you select cannot span multiple part instances.

The slave surface or region that you select becomes highlighted in magenta in the viewport.

After you select the slave surface, the constraint editor appears. The Switch button allows you to interchange your master and slave surface selections without having to start over. The Switch button is available only if you selected Surface in the previous step.

From the editor, select the Constraint enforcement method.

Select Analysis default to use the default constraint enforcement method: surface-to-surface for ABAQUS/Standard and node-to-surface for ABAQUS/Explicit.

Select Node to surface to generate the tie coefficients according to the interpolation functions at the point where the slave node projects onto the master surface.

Select Surface to surface to generate the tie coefficients such that stress accuracy is optimized for the specified surface pairing.

Toggle on Exclude shell element thickness if you want to ignore shell thickness effects in calculations involving position tolerances and adjustments for initial gaps.

Choose one of the following Position Tolerance methods:

Use computed default. ABAQUS determines the nodes to be tied using the default position tolerance. For more information, see “Mesh tie constraints,” Section 28.3.1 of the ABAQUS Analysis User's Manual.

Specify distance. You can specify an absolute distance from the master surface within which all nodes on the slave surface to be tied must lie.

Toggle on Adjust slave surface initial position if you want ABAQUS to move all the nodes of the slave surface onto the master surface in the initial configuration.

Toggle on Tie rotational DOFs if applicable if you want ABAQUS to constrain the rotational degrees of freedom that exist on both master and slave surfaces.

If desired, you can specify a value for the constraint ratio. You must toggle off Tie rotational DOFs if applicable to make the constraint ratio option available.

Click OK to save your constraint definition and to close the editor.