Ice–propeller milling loads in water based on elastic-brittle constitutive model

When ships navigate in ice-covered waters, their propellers inevitably collide with sea ice, causing safety problems. Understanding the ice loads and structural responses during propeller–ice interactions is crucial to optimizing propeller design and ensuring operational safety. Unlike conventional hydrodynamic analysis of propellers, the structural response analysis of ice-strengthened propellers operating in polar regions involves a complex nonlinear fluid–structure interaction among ice, water, and the propeller, which remains a challenging research topic in the current academic field. This study establishes a multiphase ice–water–propeller coupling model using the nonlinear finite element method to investigate the dynamic response of ice class propeller under various ice conditions. With the nonlinear finite element analysis software LS-DYNA, a sea ice model is developed by combining the cohesive element method with elastic-brittle material failure model. The arbitrary Lagrangian–Eulerian method is adopted for multiphase coupling, aimed to analyze the propeller response under combined influence of seawater and sea ice. Numerical simulation results are compared with experimental results, indicating that peak load and average errors are within 15%, and load duration errors within 5% by considering water effect. Neglecting water effect, the deviation between simulated and experimental resultant moment peak is up to 43%. An ice–propeller milling model was proposed to examine dynamic impact processes, nonlinear ice loads, and the stress and deformation distribution on propeller blades during milling. The results reveal that under direct contact, ice loads exhibit low-frequency discrete characteristics, with significant stress concentrations at blade edges and roots, and large deformations at blade tips and leading edges. The findings show that milling depth and propeller speed significantly affected load duration, with greater milling depth and ice floe velocity resulting in increased ice loads and deformation areas. The multiphase coupling model effectively simulates different ice–propeller interaction processes, providing insights into ice loads and structural responses and offering important guidance for propeller design and operational strategies in polar environments.