Can somebody help me understand the difference between the Resultant Moment (Combined Action) and Interaction principle (Discrete Action) methods for columns design in the RCDC Design settings Dialog ?
When we do column design, we generally consider axial load and biaxial moment. Accordingly we can calculate axial and uniaxial moment capacities in each direction and do interaction checks as per relevant code. This is an approximate method and conservative too. This method is identified as discrete action here.
But there is one other method. Where we can calculate resultant moment and resultant capacity. then we can do the interaction. Please read the attached document which is also available in help file. ACI code talks about this resultant method.
3D Interaction Curve.pdf
Answer Verified By: Saed Al-Halteh
Thank you very much for your help