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

RISA modeling technique

RISA modeling technique

RISA modeling technique

I am new to Risa and have run in to an issue with how to model a specific type of joint. We build a frame that has solid support rods that form an X inside the frame. Currently I am modeling them as separate beam elements with nodes at each end. In production, we do weld the rods together where they cross. For the most accurate loading simulation, should I model this as 4 elements with a node where the rods cross or continue as I am?

Any assistance is greatly appreciated.

RE: RISA modeling technique

Will these be "tension only" members?

If so, I would suggest not connecting them at the center of the X. It has nothing to do with which model is more "accurate" it has to do with the fact that when I was a support engineer at RISA (for 16 years) this was one of the most common causes of non-convergence of tension only members. Also, I'm not convinced that modeling without the connection causes any problems with the mode.

Standard Caveat: My time at RISA ended rather unpleasantly (when Netmutsck bought the company from Bruce). And, I now work for RISA's biggest competitor (SAP2000 / CSI). Therefore, take any editorial comments I have about RISA (or RISA's management) with a healthy grain of salt.

RE: RISA modeling technique

Thank you. I appreciate the insight in how the program runs. One of the members will be tension only when installed. In all honesty, we put the X in due to the frames being installed upside down regardless of our instructions.

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


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