Hello Bentley,

Regarding PDELTA Analysis Syntax on STAAD, I understand that STAAD automatically considers small and large delta effects (B1 and B2).

For us to use PDELTA Analysis to simulate second order analysis correctly can you please confirm if STAAD automatically calculate effective length factor of a member?

If STAAD automatically considers effective length factor, this allow user not to declare k value of member on parameter declaration.

Per AISC 360-10, effective length factor is required for second order analysis.