Defining the Mechanical Behavior of Virtual Bolts

You can set parameters that define the mechanical behavior of virtual bolts.

This task shows you how to:

Before you begin:

Create a virtual bolt as described in Defining Virtual Bolts.

Define Mechanical Behavior

Choose the Mechanical behavior of the bolt.

Option	Description
Deformable	Defines a realistic bolt using axial, shear, torsional, and bending stiffness values to define the connection properties. You can also define advanced behaviors such as damage and failure.
Rigid	Defines a rigid bolt, where the bolt is idealized as an inflexible solid connection that transmits all forces through the connection.
Beam	Defines a bolt as a circular beam. profile and radius. The beam radius and material properties determine the connection properties.

If you selected Deformable as the Mechanical behavior, to define the stiffness behavior do one of the following:
- Enter values for Axial stiffness, Shear stiffness, Torsional stiffness, and Bending stiffness.
- Select the Enable advanced behaviors option, then click . With this option, you can define additional connection behaviors. See Connection Properties for more information.
If you selected Beam as the Mechanical behavior, define the beam section by doing the following:
1. Click .
  The Material Palette appears.
2. Search for the material you want to assign, and click it.
3. Click OK to close the Material Palette.
4. Enter a value for the Radius.
  The beam uses a circular beam profile.

Optional: If you selected Beam as the Mechanical behavior, define the coupling at the other end of each solid layer.

The "other end" is the inside surfaces for the top and bottom layer, and the lower side of any intermediate layers.

From the Solid-solid connection options, choose one of the following:


Option	Description
Beam	Uses a beam element between adjacent solid layers
Coupling	Uses couplings with common reference node between adjacent Solid layers

If there are any intermediate layers between Support 1 and Support 2, specify the Connection Type:

Option	Description
No connection	The intermediate layers are not coupled to the bolt.
Standard	Extends the coupling region beyond the edge of the hole according to a washer diameter you define. You can edit the Washer diameter.
Tight fit	Couples the nodes on the edge of the hole.

Optional: Select Allow preload if you are simulating the bolt tightening effect. This option is not available when the bolt includes intermediate layers.
If you select this option but the scenario does not include bolt loads, this might cause convergence issues during simulation.
Optional: Select Ignore chamfers smaller than, and enter a length value.
Use this option to prevent the creation of couplings on small chamfer faces. In other words, create a standard bolt instead of a countersunk bolt. In the image below, the bolt on the left does not use this option, so the couplings connect to the chamfer face (like a countersunk bolt head). The bolt on the right makes use of the Ignore chamfers option, and creates the couplings on the upper surface (like a standard bolt head.)

Specify the Coupling type:

Option	Description
Kinematic	Directly couples edge or face supports to the motion of a reference point.
Continuum distributing	Couples the displacement and rotation of the fastening points to the average displacement of the nodes.
Structural distributing	Couples the displacement and rotation of the fastening points to the average displacement and rotation of the nodes.