A Nondestructive Differential-Pressure Test for Thin Shells

Abstract

The differential-pressure test is an original, nondestructive, experimental technique for determining incipient buckling pressures of thin shells subjected to external pressure. Extensions of the basic test permit study of many buckling parameters as well as other mechanical factors in thin-shell design and evaluation. The salient feature of the technique is the filling of the internal volume of the shell with a compressible fluid, such as water, to control the magnitude and rate of shell deformation. The incipient buckling pressure is detected by noting the point at which the difference in internal and external pressure becomes constant. Experimental verification of the technique and its nondestructive aspect is presented. Applications and limitations of the test are discussed.