Research on structural response of ice-class propeller of polar ship based on numerical calculation and specification design

Purpose This paper investigates the structural response of ice-class propeller blades under ice-loading conditions, focusing on the Canadian R-class icebreaker's propeller. The study aims to analyze static and dynamic behaviors to validate the propeller's strength and provide insights into stress and vibration patterns, supporting the optimization of propeller design and the safety of polar vessel operations. Design/methodology/approach A unified numerical framework is developed that integrates static strength analysis, ice–propeller collision dynamics, ice milling simulations, and dry/wet modal analysis. Static analysis, conducted using the ANSYS commercial software, was employed to evaluate the strength safety margin of the propeller under International Association of Classification Societies -prescribed ice loads. Finite element and SPH-based simulations of ice–propeller collisions and milling are used to compare transient stress and energy responses under different ice–propeller interaction modes, highlighting the governing role of milling loads under extreme conditions. The dry/wet modal analysis quantifies the reduction in natural frequencies and mode shape changes induced by the surrounding water. Findings The results show that the propeller blade maintains sufficient safety margins under prescribed static ice loads. Dynamic simulations indicate that blade stress, deformation, and contact force increase markedly with ice impact velocity. Ice milling generates peak stresses of approximately 200 MPa, significantly higher than those induced by direct impacts, yet still below the allowable material limit, suggesting that milling loads may govern the structural design envelope. Modal analysis reveals that boundary constraints reduce natural frequencies by about 8% in air, while fluid–structure interaction leads to an average frequency reduction of approximately 30% in water. Originality/value This study presents a comprehensive analysis of ice-class propeller behavior under ice-induced loads, integrating static strength, dynamic impact, ice milling, and modal characteristics in both air and water. The novelty lies in quantifying ice milling as a governing load, showing its significant impact on propeller strength. Additionally, this work introduces the influence of wet modal effects, demonstrating a ∼30% reduction in natural frequencies in water. The findings offer valuable insights for the design, optimization, and reliability assessment of ice-class propellers, addressing key engineering challenges in extreme polar environments.