RISA modeling technique

[Brian C]

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.

 

[JoshPlumSE]

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.

 

[Brian C]

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.