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!
  • Students Click Here

*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

LS-Dyna bolt modelling with pre-load, contact beams & Dynamic relaxation

LS-Dyna bolt modelling with pre-load, contact beams & Dynamic relaxation

LS-Dyna bolt modelling with pre-load, contact beams & Dynamic relaxation

Hi all,

I am trying to model bolted joints for double shear (coupon level) with contact beams method, using *INITIAL_AXIAL_FORCE_BEAM and dynamic relaxation(DR). I have got the model to initialise successfully with correct preload as desired. However, I found that the DR stage takes too long. In order for DR to converge after pre-load rampup (pseudotime > load rampup time), I have to have a very tight tolerance (DRTOL) of 1E-09! This however takes way too long to initialise even on my coupon level model. As the motivation is to apply the learning from this into full vehicle model, such long time for DR to converge is not feasible. So I have tried few things to try and improve the situation - please see the attachment.

In a short summary, I am trying to optimise the dynamic relaxation phase so that it can be used in full vehicle simulation without excessive & un-necessary run time penalties. However, I am struggling to make sense of the output I am seeing. Request someone to please help me understand.


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


eBook - Simulation-Driven Design With SOLIDWORKS
Simulation-driven design can reduce the time and cost of product development. In this engineering.com eBook, we’ll explore how SOLIDWORKS users can access simulation-driven design through the SOLIDWORKS Simulation suite of analysis tools. Download Now
eBook - Integrating the Engineering Ecosystem
Aras Innovator provides multiple options for integrating data between systems, depending on the scenario. Utilizing the right approach to meet specific business requirements is vital. These needs range from authoring tools, federating data from various and dissimilar databases, and triggering processes and workflows. Download Now
Research Report - Simulation-Driven Design for SOLIDWORKS Users
In this engineering.com research report, we discuss the rising role of simulation and the paradigm shift commonly called the democratization of simulation. In particular, we focus on how SOLIDWORKS users can take advantage of simulation-driven design through two analysis tools: SOLIDWORKS Simulation and 3DEXPERIENCE WORKS. Download Now

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