Posting this thread to break the ice. Modelling domes is very easy in Etabs/SAP. All you need to do is to draw the curvature of the dome in elevation by a series of straight lines, but draw only the one half. Then using the apex at centre point, radially extrude the line say 24 times at 15 degree intervals (or 48 times at 7.5 deg intervals. This feature is under Edit> Extrude Lines to areas. You can further use this geometry for Finite Element Analaysis.