Cross Bore Size and Thickness Ratio Effects on Stress Distribution along the Transverse Plane of a Radial Circular Cross Bore in Elastic Pressurized Pressure Vessels

The effects of the size of the cross bore and the ratio of vessel thickness on hoop stresses and stress concentration factors were studied across the transverse edge of radial circular cross bore. The analysis was done on seven vessels with a radial cross bore having the ratio of thickness ranging between 1.4 and 3.0 using finite element method. The investigation was done in five radial plain circular cross bores with bore ratio of 0.1, 0.3, 0.5, 0.7 and 1.0. In general, the hoop stress magnitudes of the plain cylinder were lower than those given by the cross bored cylinder. It was further noted that vessels with thickness ratio of 1.4 and 3.0 gave the highest and the lowest magnitude of hoop stresses, respectively. The hoop stress increased with increasing cross bore size, irrespective of the ratio of vessel thickness. At the intersection of the cross bore, the bore ratio of 0.1 and 1.0 gave the lowest and the highest hoop stress magnitudes, respectively. Overall, the magnitude of stress concentration factor (SCF) in cross bored vessels was greater than that of plain cylinder across the cylinder thickness. Similar to the hoop stress, as the cross bore size increased, the corresponding SCF magnitude also increased; particularly in the areas in close proximity to the cross bore. For the whole range of thickness, the SCF at the intersection for the smallest cross bore size ratio of 0.1 were found to be .  <  < 3.04, whereas, the SCFs magnitude of the other sizes of the cross bore exceeded to 3.04 at the bore intersection