INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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.

Jobs

Tension rods in compression - Response spectrum analysis

Tension rods in compression - Response spectrum analysis

(OP)
Hello,

I am working on the seismic design of a dome braced with tension rods using a response spectrum analysis according to ASCE 7-10.
I know that response spectrum analysis cannot handle non linear elements and that my tension rods can enter in compression.

My problem is that I have some combinations for which all the tension rods are in compression and other combinations for which all the tension rods are in tension. Is it realistic ? Does it mean that there is a problem from the analysis ? Or does it mean that actually my tension rods should be totally dummied for the design under the combinations where they are all in compression (is there a way to avoid that ??).

Thanks.

RE: Tension rods in compression - Response spectrum analysis

Non-linearity in linear analysis including response spectrum is always difficult. If you have symmetrical X bracing in a frame, you might justify that the global behavior is as if you had only a single diagonal which worked in both tension and compression.

Alternatively, if the tension rods are pretensioned and never go into compression, they are linear!

RE: Tension rods in compression - Response spectrum analysis

I have setup a nonlinear case first which buckles the braces using an equivalent static load distribution and then used the results of this case to do a modal or response spectrum analysis so you have the appropriate braces in tension being the only ones considered for a certain direction of loading. Setup cases for both directions as required.

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!


Resources


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