Inverse identification of continuously distributed loads using strain data

Operational load and stress data are useful for structural integrity management and damage prognosis of aerospace systems. Identifying aerodynamic loads by monitoring strain is not easy because the loads are distributed continuously over the structureʼs surface. In this study, we propose a flexible method for interpolating a continuous load distribution in order to identify the full-field aerodynamic load from strain data acquired at a number of discrete points. Our method uses the conventional finite element method and pseudo-inverse matrix, and we further extend it by coupling with an aerodynamical equation. Numerical simulations show that this extension improves the estimation accuracy when only a limited amount of strain data is available. The effects of measurement error are also discussed. It is concluded that the rank reduction method improves the estimation accuracy and that use of a proper aerodynamical restriction can suppress the adverse effect of measurement error.