Flanged Acrylic Plastic Hemispherical Shells for Undersea Application

The effects of an equatorial flange and a nonuniform wall thickness upon the critical pressure and stress distribution in acrylic plastic hemispheres have been investigated by experimental and analytical methods. Forty acrylic hemispheres were fabricated and tested to destruction under short term hydrostatic pressure applied on the convex surface. Dome apex displacements were obtained from each specimen and strains were obtained from a selected few. A finite element elastic analysis was performed on one window configuration for two different boundary conditions and the experimentally derived stresses were used to determine which boundary conditions was the best for analytical analysis.