Static Aeroelastic Stiffness Optimization and Investigation of Forward Swept Composite Wings

Abstract

In this paper we present a detailed investigation of the aeroelastic optimization of swept forward composite wings. The wing is allowed to have variable stiffness, i.e., a varying thickness and stiffness matrices in the wing skins, and the use of balanced and unbalanced laminates is considered. Aside from common mass and stress responses, aeroelastic responses like aileron effectiveness, divergence and wing twist are also considered. Taking mass as an objective function, different sets of constraints on the structural and aeroelastic responses are investigated. The influence of minimum aileron effectiveness, divergence pressure and twist on the wing skin mass is analyzed. Load alleviation is a direct consequence of the mass objective and inherent to optimization with aeroelastic loads. Therefore is not necessary to consider it explicitly as a response. The essential difference of balanced and unbalanced laminates with their effects on mass and stiffness distribution is presented, and the influence of leading edge sweep angle on the optimized skin masses is investigated, subject again to variable sets of constraints.