Study on cross-sectional shape of outer cylinder for twist type morphing blade using double cylinder structure

Abstract

Previous study has shown the effectiveness of twisted morphing wing with a double-cylinder structure. The purpose of this study was to obtain the knowledge on the appropriate cross-sectional shape of the outer cylinder in the double cylinder structure in order to achieve high bending rigidity and low torsional rigidity simultaneously. The theoretical formulas about the bending and torsional multi-beam structure in the outer cylinder were derived. The effectiveness of the theoretical formulas was demonstrated by comparing with the numerical simulation using solid elements. It was observed from the results that high bending rigidity and low torsional rigidity can be achieved by having the aspect ratio of the cross-sectional shape far from 1. Finally, in order to obtain knowledge on the cross-sectional shape that can achieve high bending rigidity and low torsional rigidity, Pareto front was investigated. As a result, it was found that the aspect ratio of the cross-sectional shape should be set smaller than 1 after the beam length was set appropriately.