Modeling the slab with a plate mesh and using rigid links to connect the centers of the plate/beams is an acceptable approach. Instead of actually going in and defining the master slaves at all of the corresponding slab/beam nodes, which could be time…

You do NOT need to define composite decks one by one. If the deck properties and the direction are same, you can define a single deck covering all the members. Just identify the boundary of the deck by clicking the corner nodes and depending on the direction…

A composite deck is not equivalent to defining a rigid diaphragm. It assigns the composite properties to the beams based on the effective width of the slab. However it does not make the floor completely rigid. It also does not account for the torsion…

In STAAD.Pro one can model composite beams in a couple of ways. You may refer to the section 1.7.7 of the Technical Reference Manual to find out more on both methods. Following either of these methods one can account for the stiffness due to the deck…