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The quick method to check weather the design of slender column is fine or need to increase the column size are as follows; 1- In order to get the moments along column height accurately, divide the column into 2 or 3 segments. 2- Apply modifier. 3- Activate the P-Delta option from define menu. 4- Run the analysis and design with P-Delta and check the Non sway magnification factor i.e. delta(ns) in design summary of the column (see the pic attached). This delta(ns) must be less than 1.4. If this exceeds the limit of 1.4, increase the column size otherwise the column design is OK. Correction by seniors in my above steps will be highly appreciated.

If you set loading type as nonlinear and set the load application control as displacement, then check if you are able to get convergence in your model. I tried to model material nonlinearity of RCC in a different context, I couldn't get the desired result in SAP 2000.

Dear Engr. Salman, As you have said yours is a SMRF system, it would be better if you try to avoid reducing the torsion modifier to 0.1, however in some cases even if you increase the beam depths to 1000 mm it still fails or increase the width to say 400 mm or 500 mm. So try to increase your beam cross section but if it is still failing then reduce the modifiers. The practice of reducing the modifiers is not wrong as you are in a way transferring the torsion from beam to other structural members. Thanks and Regards, Areeb Ahmed.

You can provide steel for bending if they are significant. In order to finalize design, you need to do two things. Understand your shell local axis and how forces are reported in SAP2000/ ETABS. See topics below.