Objective Aiming at the fatigue damage problem of propeller blades under ice impact, a global rapid forecasting method for propeller blade fatigue strength in the ice - screw milling process is proposed.

Method A numerical model of ice - screw milling interaction was established based on the PD - FEM coupled algorithm. By integrating the fatigue strength evaluation method based on the modified S - N curve and Miner’s linear cumulative damage theory, a reasonable and feasible fatigue strength forecasting method for the dynamic contact ice load of ice - area propellers was proposed. And the algorithm acceleration was realized based on the Python parallel computing architecture, successfully achieving the visual representation of the three - dimensional fatigue damage cloud map of the propeller under the action of dynamic ice load.

Results It was found that under the milling condition, the fatigue strength concentration area of the blade surface was mainly concentrated in the area near the trailing edge about 0.1R, while the fatigue strength concentration area of the blade back was mainly distributed in the leading edge area about 0.3R, the middle part of the blade root chord and the blade tip part. In addition, for different propeller blades, even in the same position, due to the different sizes of ice load, the stress and amplitude are also different, resulting in significant differences in the fatigue strength of the propeller blades when milling ice blocks.

Conclusions The research results show that the proposed fatigue strength forecasting method can accurately assess the fatigue life of ice - area propellers under complex working conditions, and provides a strong theoretical support for the design and optimization of ice - area ship propellers.