I have modelled one simple structure in STAAD PRO and found that there are two types of displacement value in post processing. NODE and MEMBER.
Which displacement shall i use for comparing with allowable displacement as per BS5950 code.
For checking deflections within the member span, you would use the Beam relative displacement detail table. Nodal displacements are generally used to check column deflections (cantilever type deflection where the top displaces with respect to the base) and for checking overall structural drift. If you are carrying out a steel design in STAAD.Pro as per BS5950, the software can check for member deflections provided you specify the DJ1, DJ2, DFF parameters and also set CAN to 1 for the columns to check for cantilever type deflection. You would also need to use the TRACK 4 to get the deflection check as part of steel design.