Some Comments on the Stress Concentration and Shakedown Factors for Spherical Pressure Vessels with Flush Radial Cylindrical Nozzles

Abstract

Some previous theoretical shakedown pressures for a cylinder—sphere vessel under internal pressure are, for a certain range of parameters, shown to be too high. The error can be traced to an underestimate of the stress concentration factor owing to the use of the centreline thin-shell theory and the neglect of cylinder stresses. It is shown that much more theoretical and experimental work needs to be done to establish reliable shakedown pressures for a comprehensive range of parameters. A simple design proposal is suggested which should meanwhile prove adequate.