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. You can also define a bolt by selecting entities of the same component.

Example

Type

     
Standard or Counterbore with Nut

Circular Edge of the Bolt Head Hole and Circular Edge of the Bolt Nut Hole

Select an edge to define the bolt head and bolt nut location, respectively.

Same head and nut diameter

Select if the bolt head is the same diameter as the nut.

Head Diameter and Nut Diameter

Set the units and value of the diameter of the bolt head and bolt nut, respectively. By default, the program multiplies the shank diameter by a factor of 1.5 to obtain the head diameter.

Bolt Shank Diameter

Set the units and value of the diameter of the shank.
Countersink with Nut

Conical Face

Select a conical face to define the bolt head.

Circular Edge of the Bolt Nut Hole

See earlier description.

Nut Diameter and Bolt Shank Diameter

See earlier description. By default, the program multiplies the shank diameter by a factor of 1.5 to obtain the nut diameter.
Standard or Counterbore Screw

Circular Edge of the Bolt Head Hole

See earlier description.

Thread Face(s)

Select the hole faces from a component in contact with the threads.

Head Diameter and Bolt Shank Diameter

See earlier description. By default, the program multiplies the shank diameter by a factor of 1.5 to obtain the head diameter.
Countersink Screw

Conical Face

See earlier description.

Thread Face(s)

See earlier description.

Bolt Shank Diameter

See earlier description.

Foundation Bolt

Circular Edge of the Bolt Nut Hole

See earlier description.

Target plane

Select a plane to model a virtual wall. You must define a Virtual Wall contact condition to prevent penetration into the foundation.

Nut Diameter and Bolt Shank Diameter

See earlier description. By default, the program multiplies the shank diameter by a factor of 1.5 to obtain the nut diameter.
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.

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 .
Temperature-dependent material properties for materials assigned to bolts are not supported. Only constant material properties are supported for bolts.
  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.
At = 0.7854 * [Dn- ( 0.9382 / n)] ^2 Dn = nominal shank diameter
At = tensile stress area p = thread pitch
  n = 1/p = thread count or TPI (threads/mm or threads/in)

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.

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

Pre-load

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.

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.
For a bolt WITH a nut, torque is applied on the nut F = T/(K*D)
For a bolt WITHOUT a nut, torque is applied on the head F = T/(K*D*1.2)
Where F = the axial force in the bolt, T = applied torque, K = friction factor, and D = major diameter of the shank.

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.

The cylindrical faces of the components that form the bolt series should be coaxial. In case there is misalignment of the reference axis, the maximum tolerance is 10% of the smallest radius of the selected cylindrical faces.
  Symmetrical bolt Use symmetrical bolts for models with symmetry boundary conditions, where one or two planes of symmetry cut through a bolt with a full cross-section.

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

If you use symmetrical bolts, for a pre-load value enter the total pre-load value of the full section bolt; for bolt mass value, enter 1/2 or 1/4 of the mass of the full section bolt according to the selected symmetry type. The computed results for a symmetric bolt, such as shear force, axial force, bending moment, and torque, equal 1/2 or 1/4 of the results computed for the full model with a full section bolt.
Be cautious when you are inquiring reaction forces normal to the symmetry plane of a symmetric bolt, as the results can be erroneous. It is possible that reactions forces from a model with symmetric bolts cancel out when you run the simulation on a whole model with full section bolts.

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. Not available for composite shells.
  • 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:
    Define contact between these two faces. You can define a global, component, or a local contact. You do not need to define contact when the faces are not initially contacting and do not come into contact during loading.
  • 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.