Bolt Preloads
You can model and simulate a bolt preload on a volume or component with isotropic and temperature-independent materials in native structure mode. When you apply a bolt preload to a volume or component, the load acts to shorten the volume or component in the axial direction.
Click > 
Preload to open the Preload dialog box with the following items:
Preload to open the Preload dialog box with the following items:• Name—The name of the load. Use the color swatch adjacent to Name to change the color of the icon, the distribution, and the text displayed for the load.
• Member of Set—The name of the load set. Select an existing load set or create a new set using the Load Set Definition dialog box. Click New to open this dialog box.
 | You can create only one preload per volume per load set. |
• Solid Type—The type of solid to which you can apply a bolt preload. You can select one of the following solid types:
◦ Prismatic—A solid with two planar bases and all the side edges orthogonal to the two bases. Side surfaces must also be orthogonal to the bases. A cuboid is not considered as a prismatic volume when creating a bolt preload since you cannot determine the prismatic axis in a cuboid.
◦ General—Any solid component or volume. A general solid type need not have surfaces that are planar and parallel to each other.
| | By default, Solid Type is set to Prismatic if no geometric entity is preselected. |
• References—The type of geometric entities to apply the load. You can select volume regions or the entire model. If you select the geometric entities before opening the Preload dialog box, your selections are displayed in the References collector. Use the following items in the References area to define a general solid type bolt preload:
◦ Direction—Select a linear edge, curve, axis, or a surface to define the direction of the preload. The direction is defined to be along the selected linear edge, curve, axis, or normal to the selected planar surface. The selected geometrical reference is shortened in the specified direction.
◦ Cross-sectional Area—The cross-sectional area of the selected volume component. Type a positive real value.
◦ Length—The length of the selected volume component. Type a positive real value.
| | To approximate the preload in the solid, a negative internal strain (epsilon = -P/(EA)) is applied to the solid in the axial direction. |
• Preload—Type any real number value regardless of the solid type. The component is shortened in the applied direction of preload.
Return to About Structure Loads.