An efficient method for flutter stability analysis of aeroelastic systems considering uncertainties in aerodynamic and structural parameters

The aim of this work is to propose a novel numerical method for analyzing the flutter stability of aeroelastic systems considering uncertain parameters. Unlike the probabilistic method which is dependent on large quantities of statistical information, interval models are utilized to quantify the uncertain aerodynamic and structural parameters. An interval-form of the aeroelastic equation is established by substituting interval variables into a deterministic aeroelastic model. The flutter stability of an aeroelastic system is analyzed as a generalized interval eigenvalue problem via eigenvalue-based approach. By using the sensitivity analysis based vertex method (SAVM), interval bounds on eigenvalues can be calculated through solving two additional deterministic eigenvalue problems. A novel uncertain propagation method, called Bernstein polynomial method (BPM), is proposed to calculate the interval bounds on eigenvalues. The range of critical flutter speed can be predicted based on the upper and lower bounds on the maximum real part of all eigenvalues. For comparison, the perturbation-based probabilistic uncertainty propagation method (PPUPM) is given to determine the bounds on eigenvalues and the critical flutter speed. Numerical results demonstrate that BPM is consistent with Monte-Carlo simulation method within significantly less computation time and verify the compatibility between BPM and PPUPM. (C) 2019 Elsevier Ltd. All rights reserved.