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Abstract

A pressure hull is the primary pressure-resistant structure of a submarine. To safeguard the compressive strength of such a hull, local structural reinforcement is required for various hatches on the hull. Hatches are commonly reinforced through increasing the thickness of the hull regions around them; alternatively, hatch nozzle walls are connected with stiffened frames to maintain the continuity of reinforced structures. This study focused on a pressure hull with an elliptical hatch. A PD-5500 cylindrical pressure hull was used to design a cylindrical pressure hull structure, and a model of hatch nozzle reinforcement was designed using the Boiler and Pressure Vessel Code by the American Society of Mechanical Engineers. A numerical simulation was then conducted to calculate the hot-spot stress around the hatch nozzle and the critical buckling strength of the pressure hull. The feasibility of local reinforcement around the hatch nozzle was assessed accordingly. According to the assessment results, the reinforcement thickness of the hull around the hatch nozzle could be reduced from 56 mm to 40 mm or less. The results of this study verified that the region surrounding the hatch nozzle exhibited sufficient compressive strength without any thickness increase as long as the structural continuity was satisfactory.

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