Active aeroelastic control of aircraft composite wings impacted by explosive blasts

Abstract

In this paper, the dynamic aeroelastic response and the related robust control of aircraft swept wings exposed to gust and explosive type loads are examined. The structural model of the wing is in the form of a thin/thick-walled beam and incorporates a number of non-standard effects, such as transverse shear, material anisotropy, warping inhibition, the spanwise non-uniformity of the cross-section, and the rotatory inertias. The circumferentially asymmetric stiffness lay-up configuration is implemented to generate preferred elastic couplings, and in this context, the implications of the plunging-twist elastic coupling and of warping inhibition on the aeroelastic response are investigated. The unsteady incompressible aerodynamic theory adopted in this study is that by von-Karman and Sears, applicable to arbitrary small motion in the time domain. The considered control methodology enabling one to enhance the aeroelastic response in the subcritical flight speed range and to suppress the occurrence of the flutter instability is based on a novel control approach that is aimed to improve the robustness to modeling uncertainties and external disturbances. To this end, a combined control based on Linear Quadratic Gaussian (LQG) controller Coupled with the Sliding Mode Observer (SMO) is designed and its high efficiency is put into evidence. (C) 2008 Elsevier Ltd. All rights reserved.