Exploratory Tests of Prolate Spheroidal Shells under External Hydrostatic Pressure

摘要

Hydrostatic tests were conducted on two machined aluminum prolate spheroidal shells to evaluate existing theory for predicting elastic buckling strength. The test results demonstrated that an elastic buckling pressure forty percent greater than predicted by available theory is possible for the geometry tested. Due to these encouraging results, two titanium prolate spheroidal shells were designed for a collapse depth of 30,000 ft to explore the use of this configuration for deep-depth pressure hulls. The thicknesses of the shells were varied in order to increase structural efficiency. Two models were machined and tested to collapse under external hydrostatic pressure. The test results indicate that a titanium spheroidal shell designed for collapse at 30,000 ft with a yield strength of 110,000 psi, a length-to-diameter ratio of 2, and a thickness variation along its length would weight approximately 76 percent of its displacement. The structural efficiency of the spherical shell and several other prolate spheroidal shells are compared for this material and collapse depth. (Author)