Search

The main results of a structural analysis program concerning a conventional submarine pressure hull configuration consisting of a rib-stiffened cylindrical shell with a reinforced circular penetration under hydrostatic pressure are discussed. The mathematical solution in series form has been obtained by superposing the analytical solutions for a long, unstiffened, and unperforated circular cylindrical thin shell, closed at the ends, under external hydrostatic pressure, a long, unstiffened, and unperforated circular cylindrical thin shell under a prescribed number of arbitrary radial line loads, and a long, unstiffened, circular cylindrical shallow thin shell under arbitrary loading along the boundary of a circular penetration. During the computation, following truncation of the series, the method of least squares is employed in solving for the integration constants determined by the boundary conditions prescribed along the ribs and the reinforced penetration. The analysis has been coded and the numerical results generated by the use of a digital computer for an unstiffened as well as a rib-stiffened shell with a reinforced penetration are presented and compared graphically with experimental data available from certain photo-elastic model tests. The corresponding zone of influence of the penetration and the state of stress concentration about it are delineated.