Buckling and strength of an externally pressurized spherical shell with reinforced opening

This paper focuses on two opening reinforcement methods of spherical shells under uniform external pressure. To reduce the local weakening and buckling effects of openings in spherical shells, designs comprising the wall reinforcement and the combination of a wall and thick plate reinforcement were employed to minimize buckling instability. In addition, the equal-proportion models of two kinds of reinforcement methods were manufactured and tested. The geometry, thickness, buckling load, and final collapsed mode were measured for each spherical shell with opening reinforcement. The paper contains a comparison between theoretical predictions, numerical analysis results and experimental data for two reinforced spherical shells. The theoretical and numerical results were in good agreement. The numerical solution result, obtained by considering the real defect, was consistent with the experimental result, and the failure mode was consistent with the location of the defect.