Limit Pressures for Cylindrical Shells with Unreinforced Openings of Various Shapes

Abstract

Experimental limit pressures have been determined and compared for cylindrical shells with unreinforced openings of 26 different shapes and sizes. Deformation patterns were also studied. The shapes included circles (radius r = c), squares (side 2 c), rectangles (longitudinal side 2 c, circumferential side 2 a) and ellipses (longitudinal and circumferential semi-axes c and a respectively). Specimens of the different shapes but where dimension c was common were found to behave similarly and to have closely related limit pressures. This was predicted for specimens having rectangular and square openings by a lower bound analysis which led to a simple mathematical relationship between limit pressure and the non-dimensional parameter c/√RT, R and T being respectively the radius and thickness of the cylinder. The results are important in predicting limit pressures for cylinders having openings of shapes corresponding to curves formed by the intersection of the shell by oblique branches.