Identify aerodynamic pressure load on a 3D wing structure from strain data using surface flattening and subregion interpolation

The aerodynamic pressure load on the aircraft is vital for structural design and safety evaluation. A new method capable of identifying the pressure load on the complex surface of a three-dimensional structure is proposed. To achieve this goal, the pressure load identification technique based on subregion interpolation, which is theoretically suitable for identifying the distributed load on flat surface with arbitrary shape, will be combined with the surface fattening technique. A transfer matrix describing the relationship between pressure load on the subregion of three-dimensional structural surface and structural strain data at local measurement points is constructed, and then the pressure load on the whole surface can be identified from the strain data via a simple matrix inversion procedure. A numerical example of the pressure load identification on a curve panel is firstly used to verified the proposed method. Different noise levels in structural response, sensor placement schemes and regularization methods which may affect the accuracy of the proposed method are further investigated. Finally, the proposed method is applied on the aerodynamic pressure load identification of a 3D wing structure, which aims to demonstrate the applicability of the proposed method on real three-dimensional structures.