Specifying Contact Surfaces

To define contact in your model, you must identify the pairs of surfaces that may interact, known as contact pairs. You must select pairs of surfaces when you create the following:

  • A contact pair

  • A fastened pair

  • A pressure fitting connection property

To specify the surfaces, you may be able to select a Contact or Coincidence constraint that you created in the Assembly Design workbench when you were positioning the part instances. Alternatively, to specify contact between surfaces that are not already referred to by a Contact or Coincidence assembly constraint, you can create a general analysis connection in the Nonlinear Structural Analysis workbench or the Thermal Analysis workbench.

A Contact or Coincidence assembly positioning constraint

If you created a Contact or Coincidence positioning constraint in the Assembly Design workbench, you can select that constraint when specifying the surfaces in a contact pair. For example, in the Assembly Design workbench, you can select two surfaces to define a Contact positioning constraint. Nonlinear Structural Analysis uses the same two surfaces to define the contact pair if you select the Contact positioning constraint when you are defining contact in the Nonlinear Structural Analysis workbench. When you are positioning the part instances in the Assembly Design workbench, you must select the first and second geometric elements of the constraint. For contact the first element that you selected when creating the constraint is considered the “master” surface, and the second element is considered the “slave” surface.

When a constraint is added to the specification tree, the surfaces are listed in the order shown in Figure 8–7.

Figure 8–7 The specification tree entry for a Contact assembly constraint, showing the master and slave surfaces.

For more information about assembly positioning constraints, see Contact Constraints and Coincidence Constraints in the CATIA V5 Assembly Design User’s Guide.

A general analysis connection

If a suitable Contact or Coincidence positioning constraint does not exist, or if the constraint is not sufficient to define the contact pair, you can create a general analysis connection in the Nonlinear Structural Analysis workbench. When you are creating a general analysis connection, you must select surfaces for the first and second component of the connection. For contact the first component is considered the “master” surface, and the second component is considered the “slave” surface. The surfaces that you select must be continuous—they cannot be made up of two or more disconnected regions. See Creating General Analysis Connections for more information.