Cross bore configuration and size effects on the stress distribution in thick-walled cylinders

Abstract Three-dimensional finite element analyses were performed for closed ended thick-walled cylinders with a cross bore under internal pressure. Cylinders having either a round radial cross bore, or optimally offset circular cross bore or an optimally shaped elliptical radial cross bore were investigated. The effects of cross bore diameter size on the principal stress distribution as well as the stress concentration factors along the plain cross bores were also investigated. The results show that the hoop stress distributions as well as the stress concentration factor in a thick cylinder depend on cross bore diameter size. The maximum hoop stresses in the circular radial cross bore cylinders approach 1·5 times that in the radial elliptical or offset cross bore cylinders. The stress concentration factor at the bore of the circular radial cross bore, optimally shaped radial elliptical cross bore and an optimally offset circular cross bore is 2·30, 1·52 and 1·33, respectively.