Design and Optimization of a Double-Layer Composite Pressure Vessel Structure

Ballast tank is the main pressure component of underwater intelligent equipment, material selection and structural design are important factors restricting its diversified functions. In order to realize the functional application and lightweight of underwater ballast tank, the structure and materials of ballast tanks were studied. The design uses carbon fiber resin matrix composite material as the shell and titanium alloy material as the inner liner to prepare the underwater double-layer cylindrical water-tight structure ballast tanks. The fiber layer is selected as the layering scheme of [90°/90°/0°]s. The weight can be reduced by 23% compared to the ballast made of titanium alloy. Based on Abaqus finite element analysis software, the actual working conditions of the ballast tank are simulated, and the analysis shows that the cylinder meets the strength requirements. At the same time, the stability of the cylinder is studied, and the critical load of the instability of the double-layer underwater ballast tank is 22.15MPa by buckling analysis. The physical object was processed, and the pressure experiment of 1.5MPa and 2MPa was carried out on the physical object. The experimental results met the requirements of strength and stiffness.