Stiffness Experiment of Large Deformation and Large Aspect Ratio Elastic Wing Model

In order to improve aerodynamic efficiency and obtain large lift-drag ratio, unmanned aerial vehicles with high altitude and long endurance usually have large wing aspect ratio and large flexibility, resulting in static aeroelastic deformation up to 25% of wing half-extension. Therefore, aerostatic-elastic influencing factors must be included in the design objective. In the design and development stage of aircraft, the research mainly relies on wind tunnel test and numerical calculation. For wind tunnel tests, the elastic model focuses on meeting the requirements of speed-pressure ratio and stiffness ratio. After the elastic model has been processed, ground stiffness tests are required to check the similarity of the elastic model to the rigidity of the prototype aircraft. In this paper, the characteristics and methods of stiffness test of large aspect ratio wing under large deformation are introduced and the test results are briefly analysed based on a wing elastic model with large aspect ratio at high aerodynamic centre speed.