Evaluation of the structural integrity of assemblies often involves proper modeling and analysis of bolted connections, including the consideration of bolt preload effects. Bolt pretension is a method used in structural analysis to simulate the preload that is applied when a bolt is tightened. This preload is important as it can affect the performance and safety of bolted joints. In Discovery, you can use the bolt pretension to model a bolt which is holding together two bodies by applying a known value of clamp force, grip length adjustment, or torque (to simulate the tightening of a nut or bolt). The Bolt Preload condition in the Refine stage applies a pretension load to a cylindrical face — typically to model a bolt under pretension. In addition, in both Explore and Refine stages, you can assign a bolt preload to a 1-D beam as a replacement to a 3-D bolt, created through bolt assignment tool.

This video goes over various aspect of bolt pretension, how it can be applied in Discovery.

Please refer to this knowledge article to understand how you can use the bolt idealization tool to create 1D bolts: Structural Simulation using Bolt Idealization