Abstract: In order to improve the structural performance of H-type vertical axis wind turbine blades under the combined loads of aerodynamic force,centrifugal force and gravity,a multi-objective optimization method was proposed.A mathematical optimization model was established with the minimum mass and maximum stress as the objective function and the maximum deformation as the constraint.Through the Fluid-Structure-Interaction (FSI) method,the real-time and accurate extraction of the blade surface pressure was realized,and the finite element model of the blade under the combined load was established.Based on Optimal Space-Filling (OSF) method and Kriging model,the response surface model of each variable to stress,mass and deformation was established,and the sensitivity and change trend were analyzed.Finally,the Multi-Objective Genetic Algorithm (MOGA) was used to obtain the optimal solution of each variable,and the results were verified.The results showed that the optimized blade mass was reduced by 14.7 %,the maximum reduction of the maximum stress at each azimuth was 7.8 %,and the maximum reduction of the maximum deformation was 16.7 %.The research results can provide a reference for the structural optimization design of blades under combined loads.

Key words: vertical axis wind turbine, blade, Fluid-Structure-Interaction (FSI), Kriging model, Multi-Objective Genetic Algorithm (MOGA)