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

Tension Only Truss Members

Tension Only Truss Members

Tension Only Truss Members

I am working on the load rating of a historic truss bridge. All the diagonals are steel rods which can't take any compression. I tried to use RISA but the program can't handle Tension Only (even you turn on the Euler Buckling option) and keep the truss stable at the same time. Even worse, the program locked almost all the truss joints due to instability but DID NOT report the lock as it normally does for other models. I contacted the technical support at RISA and they told me the only way to let the model run is to let every truss member carry both tension and compression. I wonder if anyone here used other program to handle this type of problem? I have SAP2000 and ANSYS on my computer. ANSYS sure is powerful but the problem will be with the moving load generator. How about SAP? What do you do with tension only brace analysis uner building lateral forces?

RE: Tension Only Truss Members

Sap would be a good choice for this type of analysis, it has moving load application as well as nonlinear nlink framing elements which can be designated as tension-only.  The procedure would be similar to that for tension only braces in ETABs per FAQ802-1169

RE: Tension Only Truss Members

Thanks WillisV! I never used SAP but will give it a try. I've never had ETAB either. Seems like it is not as simple as I thought of. No wonder RISA can't solve the problem.

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