Research On SMA Coil Spring Based Morphing Wing Actuator

Morphing wing air vehicle is able to change its shape to adapt different flight conditions and achieve optimal aerodynamic characteristics. As usual, the wings of morphing wing air vehicle should be deformable. However, traditional mechanical drive method has the problems of complex transmission system and large space occupation, which influences the mobility of aviation. With the advantages of high power to weight ratio, low requirements for drive conditions and simple drive structures, shape memory alloy is a promising research field in the study of wing drive as a clean and efficient drive element.This paper designs a shape memory alloy based wing trailing edge actuator, and conducts tests on it. The main work is as follows:Firstly, this paper designs a wing trailing edge actuator which is composed of shape memory alloy coil spring and worm gearing. The proposed actuator increases output torque and meets need for large deformation of the wing trailing edge. Through modeling analysis, output performance of actuator in different conditions is deduced. The optimal excitation method is determined by comparing three kinds of heating methods.Secondly, this paper carries out three point bending test for actuator material to obtain the heat treatment method. A temperature control testing system is designed for the proposed actuator element. Based on the temperature control testing system, the mechanical performance of the actuator element is tested, and the preloaded angle and mechanical performance parameters are obtained respectively.Finally, this paper conducts periodic excitation test for the proposed actuator to achieve optimal heat frequency. The actuator is tested experimentally with load and without load, which verifies the load capacity of the actuator and the ability to excite large angle deformation of wing trailing edge.