Combined effects of thermal stress and ice impacts on polar ship hulls: A numerical study

In polar environments, the combined effects of low temperatures and ice loads greatly influence the structural response of ships. While existing studies have primarily focused on individual factors, systematic analysis of their combined effects is lacking. At extremely low temperatures, temperature variations not only alter material properties but also interact with ice loads, complicating hull safety and inducing more complex nonlinear responses. To address this gap, this study adopts a coupled approach, combining Computational Fluid Dynamics (CFD) and explicit finite element methods to analyze hull structural responses at temperatures of -10°C, -30°C, and -60°C, with ice velocities of 3 m/s, 5 m/s, and 10 m/s. The results show that the temperature gradient significantly affects stress distribution, particularly within 0.8 meters above the waterline, where stress concentrations increase with decreasing temperature. At -60°C, thermal stresses suppress the growth of ice-load-induced stresses but amplify nonlinear deformation, increasing overall deformation by 79% and significantly enlarging displacement peaks. This study highlights the complex interaction between thermal stresses and ice loads, revealing that the preload effect at low temperatures amplifies structural deformation, potentially leading to substantial deviations in safety assessments. These findings provide critical theoretical support for the design and safety evaluation of polar vessels, emphasizing the need to fully account for the combined effects of thermal stresses and ice loads in polar ship design.