9 - Design of submarine pressure hulls to withstand buckling under external hydrostatic pressure

Abstract

Various methods of calculating the theoretical collapse loads for a pressure vessel under uniform external hydrostatic pressure are presented. The methods are based on various design codes: PD 5500 for vessels under external pressure, and the design charts of Ross of the University of Portsmouth. Current design methodology, PD 5500, was found to be difficult to use and gave inaccurate collapse pressures for some large-scale pressure vessels. Moreover,PD 5500 appeared to be too conservative for one mode of failure and too pessimistic for another mode of failure. A full-scale ‘theoretical’ pressure vessel was used and the described methodologies were applied in its design to see if there were any similarities between the methods.