The Design And Research Of Distributed Multi-freedom Active Morphing Wing

Morphing aircraft can change its shape in flight according to the changes of external environment and flight status, thus geting the best aerodynamic layout and enhancing flight performance. Morphing wing is an important part of the research of morphing aircraft. This thesis will do research in the distributed multi-freedom active morphing wing.Based on the differential drive principle of shape memory alloy (SMA), the concept of Active Morphing Unit is made up. The working principle of Active Morphing Unit is described. The mathematical model of Active Morphing Unit is established. The kinematics equations of Active Morphing Unit are derived. Using modular idea, a certain number of Active Morphing Units are combined together according to certain combine strategy, making the distributed multi-freedom active morphing structure. And the kinematics model of the morphing structure is also established.Based on the classic SMA constitutive equation, using the relevant theory of mechanics, heat transfer, the mathematical models of SMA are established. SMA performance testing platform is designed and built. A series of tests of SMA under different experimental conditions have been accomplished. And the key performance parameters of SMA are obtained, providing important guidance for the use of SMA on the structural design.Based on the concept of Active Morphing Unit and the distributed multi-freedom active morphing theory, using the SMA mathematical model and the SMA performance parameters, a new kind of Active Morphing Unit with lock-release mechanism is designed. Statics and kinematics analysis are made for this morphing unit. The strategy of combination along two vertical axes is adopted. The static and dynamic analysis of the distributed multi-freedom active morphing wing structure composed of 8 units are made, verifying the structural strength, obtaining the first 6 natural frequencies and corresponding vibration mode.The experimental model of Active Morphing Unit is completed and the test bed is set up. Lock-release mechanism experiments, cell rotation experiments and cell stiffness experiments are carried out. Experimental conclusions show that the proposed Active Morphing Unit is feasible.