Connector - Bolt

A Bolt can connect two components, multiple components, or a component and the ground. You can define bolts through a mixed stack of solids, shells and sheet metal bodies.

Type

The value for Bolt Shank Diameter should be equal to or less than the diameters of the Thread face(s).

Tight Fit

Select if the radius of the shank is equal to the radius of the cylindrical faces associated with at least one of the components. A cylindrical face set to Tight Fit is rigid and deforms with the shank as a rigid body. Example of a tight fit bolt connector.

Shank Contact Faces . Select one or more cylindrical faces that are in contact with the shank. If you select multiple faces from a component, they must have the same axis and radius.

Material

Simulation selects Alloy steel from the SolidWorks Material library as bolt material by default.

• Custom. Define your own material properties. Set the Units , Young's Modulus , Poisson's Ratio , and Thermal expansion coefficient .

• Library. Click Select Material to open the Material dialog box.

The program does not maintain a link to the selected library. If you edit the library, the changes are not reflected for the bolt.

• Include mass. Includes the Mass of the bolt in the analysis.

Strength Data

• Known tensile stress area. Select this option if the tensile stress area (minimum area of the threaded section of the bolt) is known.

• Calculated tensile stress area. Select this option to let the program calculate the tensile stress area of the bolt.

• Tensile Stress Area. Set the known tensile stress area for the bolt.

• Thread Count. Enter the number of threads per inch, or per millimeter measured along the length of the fastener.

• Bolt Strength. Set the strength of the bolt's material and its unit.

There are three commonly used strength parameters for bolts to estimate bolt failure. Yield strength, Ultimate Strength and Proof Strength (90% of Yield strength). The most commonly used parameter is the Yield strength of the bolt's material or grade, but users should choose a strength value that is most appropriate for the application.

• Safety Factor. Set the safety factor for the pass/no pass design check of the bolt. The bolt fails when its combined load exceeds the ratio of 1/Safety Factor. Click here for the safety check for bolts.

Pre-load

• Units .

• Axial . Select this option if the axial load on the bolt is known.

• Torque . Select this option if the torque used to tighten the bolt is known.

Friction Factor (K) . The program uses this factor to calculate the axial force from a given torque.

Advanced Option

• Bolt series. Select to bolt more than two components together. For nonlinear studies you can bolt more than two solid components.

. Select the cylindrical faces of solid bodies or circular edges of shell surfaces from the middle components. For nonlinear studies, select a cylindrical face from a solid body.

• Symmetrical bolt. If one or two planes of symmetry cut through the bolt, you can define a symmetric bolt.

Reference Geometry . For 1/2 symmetry bolts, select the plane or planar face of symmetry.

If you use symmetrical bolts, enter 1/2 or 1/4 of the total pre-load value and 1/2 or 1/4 of the total mass of the bolt according to the selected symmetry type. Also, when you list bolt forces after running a study, the results equal 1/2 or 1/4 of the total force.

Symbol Settings

• Edit color. Select a color for the symbols.

• Symbol Size . Set the size of the symbols.

• Show preview. Toggle the visibility of the bolt in the graphics area.

Notes

• Available for static and nonlinear studies.

• The bolt connector formulation is an approximation of a complex nonlinear behavior. It provides accurate results when the bolts are under tension. In loading scenarios where the bolts are under compressive loads, the axial forces of bolt connectors may not be accurate. In such cases, a decrease in preload bolt force can result in a "loosening" of the bolt and loss of contact between the bolt and the components. This behavior cannot be captured by the bolt connector formulation in Simulation. For these cases, model the actual bolt and define no penetration contact sets between the bolt and the components.

• You may need to define a contact condition to prevent interference as shown:

• You have the option to consider the shell thicknesses for no penetration contact between two shell surfaces for static studies.

• Hole Series

• When you add a bolt to one hole in a hole series, the software allows propagating bolts to all the other holes in the hole series.

• The software groups the connectors based on the hole series in a separate folder.

• Editing any one bolt in the group applies to all connectors in the series.

• You can dissolve the bolt series and break the link to allow editing of each feature separately. Right-click the folder containing the series and select Dissolve Bolt Series.

• You can restore the connector series after you dissolve it. Right-click the folder that contained the series and select Reestablish Bolt Series.