Parametric Study of Unstiffened and Stiffened Prolate Spheroidal Shells under External Hydrostatic Pressure

摘要

Hydrostatic tests were conducted on a series of 25 unstiffened, epoxy resin prolate spheroidal shells to study the elastic buckling behavior of this shape for geometries in the following range; length-to-diameter ratios from 1.25 to 4.00 and thickness-to-radius ratios from 0.02 to 0.10. These test results demonstrate conclusively that existing analyses for predicting the elastic buckling strength of prolate spheroids are inadequate. Empirical elastic buckling equations, accurate within 5 percent for the range of geometries considered, were determined from the test data. Based in part on these results, an approximate method was developed for predicting the elastic buckling strength of ring-stiffened prolate spheroids. Test results on two stiffened epoxy resin models showed excellent agreement with the pressures calculated by this method. Equations are also proposed for the inelastic buckling of unstiffened and ring-stiffened prolate spheroids. Results are presented to illustrate the potential of these shells for deep-depth applications. (Author)