Geometric Constants in Plain Cross-Bored Cylinders

Abstract

A three-dimensional FEM computer program was developed to establish the stress distributions and SCFs in thick walled cylinders with flush and nonprotruding plain cross bores under internal pressure. The displacement formulation and eight-noded brick isoparametric elements were used. The Frontal solution technique was used due to the limited computing facilities. In the far field, the FEM stresses and displacements were in good agreement with the through thickness analytical values. The variation of SCF with d was established for various thickness ratios. For k>1.25, the maximum hoop stress occurred away from the crotch corner when d≤0.2. For k=1.25, the maximum hoop stress occurred away from the crotch corner when d≤0.15. For k≥1.75, d was found to be a geometrical constant equal to 0.2 where the k values have a SCF of 2.734. For k<1.75, d was found to be a geometrical constant equal to 0.11 where the k values have a SCF of 2.67. A new categorization of cylinders has been proposed: thin shells, thick shells, and thick cylinders.