Defining embedded region constraints

You use an embedded region constraint to embed a region of the model within a “host” region of the model or within the whole model. You can create an embedded region constraint by specifying the embedded region, the host region, a weight factor roundoff tolerance, and an absolute exterior tolerance or fractional exterior tolerance. For more information, see Embedded Elements.

Related Topics
Understanding constraints
In Other Guides
Embedded Elements

  1. From the main menu bar, select ConstraintCreate.

    Tip: You can also create an embedded region constraint using the tool in the Interaction module toolbox.

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

    1. Name the constraint. For more information about naming objects, see Using basic dialog box components.
    2. From the Type list, select Embedded region, and then click Continue.

  3. Select the embedded region using one of the following methods:

    • Select a region in the viewport. (For more information, see Selecting objects within the current viewport.) Click mouse button 2 to indicate that you have finished selecting.

      If the model contains a combination of mesh and geometry, click one of the following from the prompt area:

      • Click Geometry if you want to select a geometry region.

      • Click Mesh if you want to select the region from a native or orphan mesh selection.

    • Use an existing set to define the region. On the right side of the prompt area, click Sets. Select an existing set 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 Sets on the right side of the prompt area.

    The region that you select becomes highlighted in red in the viewport.

  4. Select the host region.

    In the prompt area, select one of the following:

    • Select Region if you want to select a region in the viewport or use an existing set to define the region. Use one of the methods described in the previous step to select the host region.

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

    • Whole Model if you want to embed the embedded region within the whole model.

    The constraint editor appears.

  5. In the editor, specify values for the tolerance parameters. If you specify values for both exterior tolerance parameters, Abaqus will use the smaller of the two tolerances.

    • Weight factor roundoff tolerance. You can specify a small value below which the weighting factors will be zeroed out. The default value is 10−6.

    • Absolute exterior tolerance. You can specify the absolute value by which a node on the embedded region may lie outside the host region. If this parameter is omitted or has a value of 0.0, the Fractional exterior tolerance will apply.

    • Fractional exterior tolerance. You can specify the fractional value by which a node on the embedded region may lie outside the host region. The fractional value is based on the average element size within the host region. The default value is 0.05.

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