A non-probabilistic approach to design of composite wings including uncertainties

A non-probabilistic method is developed to optimize the design of an idealized composite wing through consideration of the uncertainties in the material properties, fiber-direction angle, and ply thickness. In the study, the collocation interval analysis method based on the first class Chebyshev polynomial approximation is presented to predict the upper bound and lower bound of the flutter speed. Compared with the interval analysis method based on the first order Taylor expansion, the proposed method is a non-gradient algorithm using several collocation points which improve the precision of results owing to better approximation of the flutter speed response function. A non-probabilistic reliability criterion is defined, indicating the non-probability of failure due to flutter, and is used to determine successfully the optimal design of the composite wing.