Flutter Reliability Analysis of an Aircraft Wing: A Comparative Study

Abstract

In this paper, a comparative flutter reliability study is presented for various types of limit state functions using first-order second moment (FOSM) method and the same is compared with Monte Carlo simulation (MCS). For the reliability study, a straight cantilever wing is considered in low subsonic flow, where aerodynamic modeling is based on Theodorsen’s aerodynamic-based strip theory, and for structure, finite element method (FEM) is used. Various parameters such as dimensionless static unbalance, mass moment of inertia, bending stiffness, and torsional stiffness are considered as independent Gaussian random variables. Results show that the probability density functions (PDFs) of various types of limit state function change with parameters, and also for some parameters, the distributions are not unique. The cumulative distribution function (CDF) of flutter velocity among different forms of limit state function obtained from FOSM method is best represented by flutter margin-based limit state function. Among various parameters considered, the most sensitive parameter is torsional stiffness and the least is bending stiffness