Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

How To Run FEA on Nut-Bolt Assembly

How To Run FEA on Nut-Bolt Assembly

How To Run FEA on Nut-Bolt Assembly


I am trying to run a simulation for a nut-bolt assembly. The nut and bolt are connected to a c-channel beam, I want to run a vibration simulation to find out the clamping force between the nut and bolt after a certain number of vibrations/oscillations. Can anyone give me any tips for how to go about this? I haven't really done much simulations/FEA since I finished my undergrad last year so any info will be helpful.


RE: How To Run FEA on Nut-Bolt Assembly

What is the nature of vibration (steady-state, transient, random) ? How is the structure supposed to be supported and loaded ?

RE: How To Run FEA on Nut-Bolt Assembly

I am thinking of applying a cycle of steady-state vibrations (i.e. apply steady-state vibration n amount of times and see the affect it has on the clamping force). The c-channel beams are used for warehouse racking, the nut-bolt assemble 2 safety bars perpendicular to the c-channel, so there are 2 c-channels with 2 safety bars perpendicularly assembled to the c-channels. The loads are applied to the safety bars.

RE: How To Run FEA on Nut-Bolt Assembly

Then harmonic analysis will do the job. You just have to connect the parts (with bonded contact), apply boundary conditions and loads. They will be harmonic by default and you can also define their variation with frequency. Then specify the range of frequencies to do the sweep.

RE: How To Run FEA on Nut-Bolt Assembly

What mechanism do you suppose will change the clamping force?

RE: How To Run FEA on Nut-Bolt Assembly

The goal is not to have me read the paper and extract the mechanisms you are looking for. The goal is for you to decide what factors there are so you can match them to what an FEA can actually simulate.

RE: How To Run FEA on Nut-Bolt Assembly

To give a hint - the major reason for loss of tension is embeddment - randomly located variations in high spots on the order of 0.0001 inch take the majority of the initial load. Repeated high loads cause these highly stressed points to deform, lowering the overall separation and the preload. To simulate that you need to have the ability to generate a randomly rough surfaces and allow for incremental deformation, possibly with very small areas of fatigue failure. The overall stress levels will remain in the elastic region so a typical FEA will never detect/simulate the effect.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close