You are very correct Sir. RC designer will not design circular beam which is nothing but a combination of many chords of a circle. For RC designer it is essential that the beams forming member should be collinear in order that a member could be formed. However Staad pro, I trust will give you design for the various segments of the beam from which a common reinforcement design for the beam can be created. In fact circular plate and beam according to me should be used for modeling and loading the structure but not for designing.
I call upon other members too, who are not in agreement with me, to offer their opinion to help me as also the member who initially raised the query.