Before running P-Delta analysis, always check the model for simple modal analysis and gravity loads to make sure that analysis model has no stability issues or other warnings/errors.
I have tried two methods for running P-Delta, both are explained below, hope this will be helpful.
Method 1: Initial P-Delta
1. Define load case for e.g “P-Delta” with
2. Include all dead load cases in that P-Delta case
3. For all load cases click on ” the Stiffness at end of nonlinear case” to activate it and select “P-Delta” load case in the drop down menu.
4. Run the analysis, SAP will include the P-delta effects.
Method 2: Non-Linear Load combos
1. Convert all the load combos into Non-Linear P-Delta case
2. For all other load cases keep the zero initial condition
3. Run the analysis, it will include the P-delta effects.