Optimization of Composite Rotor Blade Using Merged Genetic Algorithm and Finite Element Method

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Abstract

In this paper, an optimization method for both weight and displacement of composite blades is presented. In   order to hold issues such as aerodynamics and acoustic unchanged, airfoil shape during optimization process remained constant. To achieve the ultimate goal, only blade lamination was changed. In order to achieve minimum weight for each part of the structure, the lowest layers are forecasted according to the required strength. Hence, the blade is divided into different parts. In optimization process, while focusing on weight and displacement reduction, layers integration must be assured. For desired performance, during optimization process, mass center location must be placed ahead of the aerodynamic center of blade. Weight reduction is in contrast to the displacement changes, and reduction in each of them would lead to an increase to the other. In optimization process, any changes in lamination of each part would influence the performance of the other parts. Therefore, in this paper, by making changes in genetic algorithm and defining appropriate objective function, design variables and other constraints, all of the above requirements are satisfied. Meanwhile, the natural frequencies of the optimized blade structure were in an acceptable range. Results and performance of the optimized blade are quite acceptable in comparison to the ordinary blades.