2019 Volume 18 Pages 151-159
A morphing wing has been studied to improve aerodynamic performance by deforming the geometrical shape seamlessly and continuously. A compliant mechanism has been proposed as the internal structure to achieve the desired deformation of the morphing shape. This study proposes the multi-layered compliant mechanisms as the internal structure of the morphing flap for improving the design flexibility of the deformation shape. Each layer has an independent structural configuration, but is connected at the wing skin to deform as a morphing flap under an independent applied load. The optimum configuration is obtained by the level set-based topology optimization. In order to perform the optimization with reasonable computational effort, the two-dimensional structural model is adopted to each layer, where the deformation shape at the airfoil skin generated by each layer is regularized to coincide with each other. Through numerical examples, the optimum configurations of the multi-layered rib to achieve the desired deformation under the prescribed load condition are illustrated. Then, validity of the two-dimensional structural model in the topology optimization is demonstrated by comparing with the deformation analysis by using the three-dimensional model.