2 Replies Latest reply on Aug 8, 2017 11:20 AM by Ryan Dark

    Preload on solid bolt

    Kenneth Larsen

      Hi, I have two plates, one with a hole and another with a threaded hole, I want to connect with a bolt with an applied preload. I know

      I know that I can use a bolt connector but I want to verify the contact force between the plates using a solid bolt or another way too. Any ideas of how to do it?

       

      I've tried to draw a solid bolt and the plates with following contact sets, forces and fixtures:

       

      Fixed geometry under the plate with the threaded hole.

      No penetration between the plates.

      No penetration under the bolt head and the top plate with the hole.

      Bonded contact between the threaded part of the bolt and the threaded part of the plate.

      200 kN Force from under the bolt head towards the bottom of the bolt.

      Equivalent force from the threaded part of the bolt towards the bolt head.

       

      The bolt is splittet into 3 solid bodies that are bonded together. If i meassure the free body force under the bolt head i get a result of 61.8 kN.

      The force between the bolt head and the plate is 138.1 kN and is equivalent to the contact force between the two plates.

      I would expect all these values to be 200 kN.

       

      I was thinking that if it is possible somehow to make a force pulling from one face towards another face that could do the job. The two faces should then be one representing the bolt head contact and the other should be the thread in the plate. But is that possible?

       

      I've attached the files that I've used for the simulation.

        • Re: Preload on solid bolt
          Bill McEachern

          You can use a thermal preload to shrink the bolt to attain the required pre load. You might need a multi step analysis so you would need the NL premuim version of the product. You could also use a shrink fit - just calculate the the required displacement - and make ht bolt that short with all the "interference on one side. I think the shrink fit you could use in a static analysis.

          • Re: Preload on solid bolt
            Ryan Dark

            Hi Kenneth,

            Pretty much exactly what you describe is how you might apply a bolt preload to a modeled bolt in your Simulation.  You would just be applying equal and opposite forces to the faces of the bolt and hole shank that are interacting with on another.  However, all interactions between the models would need to be No Penetration and in no way bonded.  If you bonded the threads as you describe it would prevent the preload from applying correctly.  I've linked a small write-up on the setup you are looking to do here for reference (GoEngineer - Simulation: Preload on Modeled Bolts)