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

Random Frequency Response ply stress

Random Frequency Response ply stress

Random Frequency Response ply stress

Hello Everybody!

I want to perform a random frequency response analysis for a part which has some Composite layers (modeled with CQUADS+PCOMPG cards)
To do that, first I create a 1G Frequency response (sol 111) and I add the RANDOM analysis to that through a RANDPS card with the psd curve according to RTCA DO-160.
I am interested to see the RMS stress plot, so for that I ask for the output STRESS(PLOT, REAL, CRMS)=ALL above the subcase level due to random analysis.

The problem comes when I want to plot the results
It looks like Nastran / Patran (MSC.Random) does not evaluate the RMS stress for the composite properties (PCOMPG), however it is capable to show the stresses in both cases (PSHELL & PCOMP) for each frequency in the frequency response.
I know that in older versions of Nastran was not possible to retrieve composite stresses in sol 111 or Random, but in the QRG of the version that we have (Nastran 2017.1), according to PCOMPG remark 6, it should be possible to calculate the stress in a random analysis.

Does anybody know, how to evaluate composite RMS Stress with MSC Nastran??
Thanks a lot

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