Stresses in a Pressurized Cylinder with a Hole

The stresses in a long pressurized thin hollow cylinder capped at the ends, and with a circular hole far from the ends are experimentally determined. Brittle coating, mechanical and electrical strain gages, and photoelasticity were used for the analysis. An epoxy model was loaded at room temperature to obtain brittle coating and strain gage data. The model was then heated to the critical temperature of the epoxy, loaded, and cooled to room temperature to freeze-in deformations and a photoelastic pattern. Slices were cut from the frozen model for analysis. Principal stresses have been evaluated along the longitudinal and transverse axes through the hole, and along a line at 45° to the axes and through the hole, and on the hole boundary. Both fields of isobars on the outer surface are reported. Comparison with a theoretical development for a similar case showed some stress variations of the order of 25% near the hole. From the different methods used in the experimental work it was felt that the combination of photoelasticity and brittle coating is most suitable to determine the state of stress at inner and outer surfaces of a shell.