Research On Key Technology Of Morphing Wing

Compared with traditional aircrafts, the multi-mission morphing aircraft is able to fly with higher efficiency and better performance and will play an important role in military and civilian fields. As a significant component of morphing aircraft, the morphing wing has drawn much attention and been rapidly developed in recent years. Gradually it is moving forward to the stage of practical applications from the theoretical studies in research labs. Nowadays, US scientists have proposed and studied various morphing aircrafts with different configurations. Key techniques of morphing wings have been widely and deeply studied and applied to certain aircrafts. Significant results have been obtained. In our country the research on morphing aircraft is still in early stages. Now the studies are in the phase of theoretical research or prototyping testing. There are no technically mature morphing wings which can be used in actual flight. Foreign techniques only can be obtained from the reports and there is no product and key technology that can be export to China on account of the sensitivity of the aerospace technology. Therefore, there is much need to strengthen the efforts to study the key technology of morphing wing, speed up the development of key techniques of morphing wing such as flexible skins, novel smart actuators and morphing mechanisms, and accelerate the development of aerospace career in our country. This dissertation concluded the history of development and the current status of the morphing aircrafts and morphing wings at home and abroad, classified the configurations of morphing aircrafts and analyzed the research contents. Based on the existing research status of several key technology fields of morphing wings, this dissertation aims at developing morphing wings with proprietary intellectual property rights and presents the studies on the design and optimization of the flexible skin structures and the design of the morphing wings based on the ultrasonic motors. Two morphing wings are tested and verificated. To conclude, main contributions of this dissertation are as follows.1. An in-plane corrugated cosine honeycomb support structure of telescope skin with high in-plane performance is proposed. Its in-plane characteristics are theoretically and experimentally studied and verificated by comparison study. The relationship between its out-of-plane performance and structure parameters is also studied. The structure parameters are optimized by using Optimus.2. In-plane corrugated support structures of telescope skin such as broken line type and U type honeycombs are proposed. Together with cosine honeycomb, the in-plane transverse equivalent moduli of these three structures are analyzed based on new-selected uniform structure parameters. Parameterized finite element models are set up to study the out-of-plane bearing capacity of the four structures. The performance of the four in-plane corrugated structures is discussed through comprehensive comparison.3. An NSGA-II algorithm based on bit-matrix representation is proposed with the ability of handling multiple constraints. A series of optimal result are obtained from the topology optimization of the telescope and shear skins. A hybrid multi-objective genetic algorithm is obtained by combining the proposed local optimization algorithm and the NSGA-II. Better results are obtained from the hybrid algorithm and the effectiveness of the hybrid algorithm is verificated.4. Two morphing wings driven by ultrasonic motors are proposed, designed and manufactured: the flexible trailing edge wing and the variable sweep wing. Aerodynamic performance of the two wings is studied through panel method. The flexible skin and the morphing menchanism of the flexible trailing edge wing are detailedly designed and studied, and the aerodynamic performance of the wing is verificated by wind tunnel test. The flexible skin and the morphing mechanism of the variable sweep wing are designed and the mechanical property of the wing is verificated by experiment.