Offsetting of Circular Cross Bore Effects on Elastic Pressurized Thick Cylinders

A research to determine an optimal location of a circular cross bore in thick walled high pressure vessels was conducted. Cylinders of thickness ratios of 3.0 down to 1.4 with circular cross bore at varying offset position were studied. The effects of a small circular cross bore, having cross bore to main bore size ratio of 0.1 was studied at nine different offset locations. It was established that offsetting of circular shaped cross bores appropriately reduces the magnitude of Stress Concentration Factors (SCFs). Among the nine offset positions studied, the minimum SCF magnitudes occurred between offset location ratios of 0.685 and 0.9. Besides, the optimal location was found to be at 0.9 offset position at the thickness ratio of 1.4, with a SCF magnitude of 2.312. This SCF magnitude indicated a reduction of pressure carrying capacity of 56.7% in comparison to a similar plain cylinder without a cross bore.