Aeroelastic instability and response of advanced aircraft wings at subsonic flight speeds

A unified aeroelastic model developed towards investigating the flutter instability and subcritical aeroelastic response to a sharp-edged gust load in the compressible subsonic flight speed range is presented. The aircraft wing is modeled as an anisotropic composite thin-walled beam featuring circumferentially asymmetric stiffness lay-up which generates preferred elastic couplings. A number of non-classical effects such as transverse shear, warping restraint, and the 3-D strain effects are incorporated in the structural model. The unsteady aerodynamic loads in subsonic flow are based on 2-D indicial functions in conjunction with aerodynamic strip theory extended to a 3-D wing model. The numerical results reveal that elastic tailoring and warping restraint play a significant role on the flutter instability and dynamic response of composite aircraft wings.