Bolt Selection
The Bolt Selection subnode is automatically added as a default node to the Bolt Pretension node. It is used for selecting the bolts. One Bolt Selection node is required for each bolt.
Boundary Selection
From the Selection list, choose the boundaries to define a cross section of a single bolt. This cross section must be an interior boundary. It is the section where the stress in the bolt is measured.
In 2D axial symmetry, the cross section must be perpendicular to the Z-axis.
Bolt Selection
Enter a Bolt label. The default is Bolt_1. The label is used for identification during postprocessing. If the same label is used in a Bolt Selection node and a Thread Boundary Selection node, the results will be grouped together.
If you want to include a Relaxation of the bolt pretension, enter a value or expression for r. The relaxation is an axial displacement, which is subtracted from the predeformation of the bolt.
Symmetry Detection
If a bolt is cut by a symmetry plane, the force in the modeled part is only half of the force in the real bolt. When Automatic symmetry detection is selected, this is compensated for. The program will then automatically detect when a bolt is located in a symmetry plane, and apply corrections.
If the input of the pretension load in the parent node is by Pretension force, the given force is interpreted as force for the whole bolt.
When Automatic symmetry detection is cleared, the inputs and outputs are based on the modeled cross section area.
The Symmetry Detection section is not present in 2D axial symmetry, since the bolt in that case always is axially symmetric.
As default, Automatic symmetry detection is selected. When opening models created in versions prior to 5.3, the check box is cleared in order to be compatible with the previous behavior.
See also Pretensioned Bolts in the Structural Mechanics Modeling chapter.
Location in User Interface
Context Menus
Ribbon
Physics tab with Bolt Pretension selected in the Model Builder tree: