Pressure-Stabilized Drop-Shaped Tanks

Considerable attention has been given to the behavior of extremely thin pressure-stabilized shells of revolution. Solution methods have been developed to treat the static pressurization and the static and dynamic in-service behavior of such shells. This note is intended to demonstrate the applicability of those methods to a particular class of shell geometries that are particularly efficient shapes for hydrostatically loaded shells. That class is the set of shapes required to provide constant stress (tension or compression) under hydrostatic pressure distributions (interior or exterior). This example of the use of inflatable membranes is considered in this note for reasons beyond that of its optimal stress characteristics. To date, the implementation of the solution methods developed by others has been limited to shapes for which an exact equation of the meridianal contour of the shell of revolution could be prescribed. Subsequent work has led to the development of a methodology to treat revolutes for which no such exact equations are available. The example treated herein has this characteristic and provided verification and error estimates for the computational improvement.