Multi-Objective Aeroelastic Tailoring Including Uncertainty

摘要

A probabilistic method is developed to optimise the design of an idealised rectangular composite wing subject to gust loading and flutter constraints through consideration of the uncertainties in the material properties, fibre direction angle and ply thickness. The Polynomial Chaos Expansion (PCE) method is used to predict the mean, variance and Probability Density Function (PDF) of the maximum Root Bending Moment due to a reference gust, and also the flutter speed, making use of an efficient Latin Hypercube sampling technique. 1-D and 3-D polynomial chaos expansions are introduced into the probabilistic gust and flutter models for variations of material property, fibre direction angle and ply thickness. The results were compared with Monte Carlo Simulation (MCS) and it was found that the PDFs obtained using PCE models compared very well but required significantly less computation. A multi-objective reliability criterion is defined, indicating the probability of failure due to both flutter and gusts, and successfully used to obtain robust designs of the fibre orientations, including the generation of Robust Pareto curves.