DESIGN AND ANALYSIS OF AN UNMANNED UNDERWATER VEHICLE: UNSTIFFENED AND T RING STIFFENED STRUCTURE CONFIGURATION

The structural integrity of unmanned underwater vehicles (UUVs) subjected to high hydrostatic pressure presents a significant challenge in marine engineering. This study conducts a comparative finite element analysis of unstiffened and T-ring stiffened hull configurations. Using ANSYS, the models evaluate stress distribution, deformation behavior, and buckling resistance. Aluminium Alloy AA7068 is selected for its high strength-to- weight ratio, with Retrogression and Re-Aging (RRA) heat treatment applied to enhance corrosion resistance and durability. Results demonstrate that the T-ring stiffened configuration markedly improves structural performance over the unstiffened model, offering increased stiffness, reduced deformation, and substantially enhanced buckling resistance under external pressure. Compared to flat stiffeners, T-stiffeners provide superior load distribution and overall structural stability. The numerical outcomes align closely with analytical predictions, validating the modeling approach. This study underscores the effectiveness of T-ring stiffening in developing robust, lightweight UUV structures optimized for demanding deep-sea environments.