Using Tie Detection

You can use tie detection to automatically create tie connections for touching surfaces.

You can specify a tolerance to include any surface pairs separated by a distance smaller than the tolerance value.

See Also
Ties
Connections Section
Connection Manager
About Engineering Connections in Simulations
In Other Guides
Creating Simulation Features
  1. From the Connections section of the action bar, click Tie Detection .
  2. Choose the Search domain using one of the following methods:
    • Select the entities directly from the 3D view or the model tree.
    • Select one of the following from the context menu:
      Option Description:
      All 3D part bodies Includes the main PartBody in the search domain, including all 3D geometry. This is the default search domain.
      Meshed supports Includes only the parts that are already meshed in the search domain.
      Note: After you use this option, you can select additional features from the model; these features are appended to the list.
      Warning: When calculating the distance between surfaces for 2D meshes, the search considers the part thickness (as defined in the shell section). This thickness is projected in all directions, not only along the surface normals, so tie detection might find some face pairs that are further apart than the search tolerance.
      All geometries Includes 2D and 3D features from ordered geometrical sets in the search domain, in addition to the regular 3D geometry.

    Tip: You can use the context menu to review and edit the list of features included in the search domain.

  3. Optional: Change the Search tolerance.

    This value defines the maximum separation distance between surface pairs to be tied together.

  4. From the Detect interactions on options, select Simple or Hybrid.
    OptionDescription
    Simple Select one of the following options:
    • Geometry: Searches for tie locations on geometry only.
    • Mesh: Searches for tie locations on meshes only. Both native and orphan meshes are considered.
    Hybrid Select one or more of the following options:
    • Geometry: Searches any geometry already included in the search domain.
    • Native mesh: Searches any native meshes already included in the search domain.
    • Orphan mesh: Searches any orphan meshes already included in the search domain.
  5. Optional: If the search includes meshes, you can specify an angle by which to extend the meshed faces. The default Extend by angle is 10 degrees.

    The example below shows a potential tie pair, including the effects of the Extend by angle option.

    Mesh surfaces B and X (represented in two dimensions) are parallel and lie within the tie detection distance (Search tolerance) represented by the dashed line. The adjacent surfaces A, C, and D are attached to B at the given angles. By default (without the Extend by angle option), a tie pair is created for B and X. If you set the Extend by angle option to 10 degrees, surface B is extended to include surfaces C and D. The Extend by angle tolerance is checked at each surface boundary and does not limit the total angle relative to the original surface. Surface D is included, even though it lies beyond the search tolerance, because it is now considered to be an extension of surface B.

  6. Optional: Preselect the following default options for the tie connections:
    OptionDescription
    Tie rotational DOFs if applicable

    Tie rotational degrees of freedom in addition to the translational degrees of freedom.

    Adjust secondary surface initial position

    Move all tied nodes on the secondary surface onto the main surface in the initial configuration, without any strain.

    You can edit and change any of the candidate tie features before they are finalized.

  7. From the Engineering connections creation options, select one of the following:
    OptionDescription
    One for all connection properties Creates a single engineering connection for all detected tie connections.
    One per connected parts Creates or selects engineering connections based on which parts are connected.
    One per connection property Creates an engineering connection for each different connection property.
  8. Click Find Ties.

    A separate dialog box shows the tie detection progress. When completed, a table displays the candidate tie features for surface pairs that meet the detection requirements.

    • You can right-click any row in the table to Locate, Edit, or Remove that tie feature. You can also choose Invert Selection to select the other tie features in the table.

    • In addition, you can [Ctrl]+[Click] or [Shift]+[Click] to select multiple rows in the table and then choose Edit or Remove Selected for those features. Again you can choose Invert Selection to select the other tie features in the table.

    • If you select Edit from the context menu, the Tie Candidates dialog box opens to let you enter or change parameters for all of the selected features. These options are described in Defining Ties.

  9. Optional: Repeat steps 2 and 3, then click Find Ties again to search for additional surfaces to tie.

    When you run tie detection, the tool does not create a tie pair if that pair was previously created. This is to prevent duplicate pairs.

    Locations found using the changed options are added to the table. New matches are marked with an asterisk (*). You can modify the new selections as described above.
  10. To create all of the listed tie features, click OK in the dialog box.
  11. To edit any of the tie connections after they have been created, double-click on its glyph in the model or on its name in the Feature Manager.

    The Feature Manager can also be used to locate or delete a tie.