Design and Analysis of Underwater Double-Layer Ballast Tank Prepared with Different Materials

As the core component of underwater intelligent equipment, the ballast tank plays a role in pressurizing and protecting internal precision instruments in the entire structure. The design of a more lightweight, stable and stronger ballast tank has become the focus of research. In order to explore the influence of materials on the double-layer structure ballast tank, the loading hydrostatic pressure of the cylindrical double-layer structure ballast tank made of different materials was numerically studied. Solikworks 3D design software was used to establish a finite element model of ballast tank, and the model was imported into Abaqus finite element analysis software. Different materials of ballast tanks were endowed with different material properties. Then, the actual working conditions of the ballast tank under water are analyzed by finite element method, and the external pressure of 7.5MPa is loaded to analyze the strength and stability of the ballast tank of the same size. The simulation results show that the ballast tank made of carbon fiber composite material has the advantage of lightweight, which is 59% less than that of titanium alloy ballast. The stability of titanium alloy ballast tank is excellent, and the critical load reaches 14.72MPa. Carbon fiber/titanium alloy ballast absorb the advantages of the two types of ballast has a variety of functions, can be applied to a variety of conditions, compared to titanium alloy ballast weight reduction of 24%. The carbon fiber/titanium alloy ballast tank was prepared, pressurized by 2MPa and held for 12h. The experimental results verified the structural safety and sealing reliability of the ballast tank.