Full Field Reconstruction in Aeronautical Structures Subjected to Aerodynamic Loads by a Matrix-Based Load Monitoring Algorithm

Abstract

A method for reconstructing the strain (and stress) field of the entire structure based on an equivalent set of lumped forces representative of the real boundary load condition, correlated with strain measures in discrete positions, is adopted. The method, namely the Calibration Matrix approach, is based on a least-squares minimization of an error functional defined as a comparison between discrete strain measures and a numerical formulation of the same. By assuming a linear relationship between strain and forces, the minimization process can be performed analytically, leading to a computationally very efficient algorithm that can be operated in real time and without requiring an aerodynamic training set to be defined. The method is numerically tested on a full-scale UAV wing subjected to different aerodynamic pressure loads. The results confirm the method ability to correctly reconstruct the strain (and, thus, the stress) field due to an aerodynamic pressure through an equivalent set of lumped forces, automatically adapting to different load scenarios