staad pro warnings

[ruchirak12]

HELLO,
I am new in staad, working on eccentric and concentric bracing frame.while modelling incase of x bracing i have intersected the members and beams are released MY MZ at start and end. bracings are defined as tension only. but i am getting error of instability warnings and zero stiffness. after using set print 1 command also the warnings are still coming.the model is G+20 and wind and seismic load is applied on 3 d space frame.Can anyone please help me solving this warnings..
thank you

 

[Polecat]

I got the same type of warnings when modeling an angle frame. I had released several ends of beams because they were pinned to the adjoing members. Staad came up with the warnings, but continued to complete the run. The warning message stated that Staad had automatically installed a very weak spring at the joint to make it think that there was some stability there. After that, it was able to converge and the warning was just that --- not an error.

http://www.spiraleng.com

 

[canwesteng]

What exactly is the warning? Sounds like you have a node with zero stiffness in one direction. The solution is generally to fix the end of one beam into that node, or ignore the warning.