I am analyzing an existing hung-span beam system for roof loading in an open warehouse. Column spacing is 40' o.c. I'm getting a Slenderness failure for 3 of the spans. Please advise as to why these members are failing if they should solely be in flexure.Roof Analysis.std
Hello Anthony,
In STAAD slenderness is checked for tension and compression cases. There are 2 parameters in design parameter tab, MAIN & TMAIN. By default values of MAIN & TMAIN are 200 & 300. If the member is subjected to either tension or compression STAAD checks slenderness as per those default values if no manual value is entered for them. But, if there is zero axial force then it checks for tensile case and reports the result. The same thing is happening here.
To avoid it you may bypass slenderness check by providing values for MAIN & TMAIN as 1. Please refer below link.
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/29075/steel-design-output-indicates-a-slenderness-failure
Also I would like to notify you that your file contains some warnings regarding stiffness. For your file you may delete all the releases and provide STAAD PLANE instead of STAAD SPACE in input editor file.
Answer Verified By: anthony agostinelli