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

Damping simulation

Damping simulation

Damping simulation

I have a whole vehicle chassis model (wheels,links, subframes etc) currently the bushes are linear and performing small displacement/strain, modal transient analyses in NASTRAN, with modal damping. I need to introduce better damping of the subframe hydramounts.  The only data I have from the manufacturer is a curve of dynamic stiffness and loss angle at 3 different levels of rig displacement (.1, .5, 1mm) against frequency (1-60Hz).

I have a number of tire contact patch events to evaluate the transfer function from the TCP to the body.  I have currently selected damping based on subframe frequency and velocity.  Problem is that velocity changes for every event.

Can anyone tell me the alternative methods of introducing damping within a modal transient analysis.

All ideas / suggestion appreciated.


RE: Damping simulation

You need to get out of NASTRAN and into a program that is not modally based. I think that PiUS PiRATE and Motran are the sort of program that we use to do what you are after  - I am pretty sure they are proprietary programs.

A non linear FE package /may/ work for you, but I have no experience with them.

The other option would be to export your structures as flex models and then do the whole job in ADAMS.


Greg Locock

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


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. 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