Reliability and Sensitivity Analysis of Composite All-Movable Fin Flutter

Uncertainties widely existing in composite aircraft structures make flutter reliability and sensitivity analysis highly necessary. In this work, a probabilistic approach is proposed for reliability and sensitivity analysis of composite all-movable fin flutter. To be specific, an adaptive method based on basis-adaptive polynomial chaos expansion (PCE) is developed to estimate the probability of failure, and the basis-adaptive PCE-based Sobol indices are used for measuring the contributions of input variables to the reliability over their entire uncertainty ranges. A composite beam and a composite plate are analyzed to test the accuracy and efficiency of the proposed approach. The finite element model of composite all-movable fin flutter is approximated by the basis-adaptive PCE model, which is adaptively updated by the FBR learning function. The weighed [Formula: see text]-means strategy is added to accelerate the convergence speed and reduce the number of iterations. Then the basis-adaptive PCE model is combined with numerical simulation for reliability and sensitivity analysis of composite all-movable fin flutter. Based on the results of Monte Carlo simulation, compared with adaptive support vector regression, kriging, and the traditional PCE method, it is found that the accuracy and effectiveness of the proposed method are the best for reliability and sensitivity analysis of composite all-movable fin flutter.