An investigation of the aeroelastic tailoring for smart structures concept

Abstract

This paper describes the wind tunnel research at Wright Laboratory continuing the validation effort in variable-stif fness tailored aeroelasticity for smart structures. To enhance aircraft performance, these structures employ flexible, adaptive, lightweight mechanisms to exploit rather than minimize static aeroelastic phenomena. While aircraft wings traditionally require added structure (and weight) to achieve adequate stiffness for roll control effectiveness, the variable stiffness design approach uses small changes in the wing stiffness to achieve the same roll control. This investigation examines the aeroelastic response to changes in stiffness to produce the desired roll effectiveness in a low speed wind tunnel. A simple, unswept, rectangular wing model is tested to explore the feasibility of using variable stiffness that is aeroelastically tailored to act as a force multiplier in conjunction with a small, outboard, trailing edge control surface (CS). This wind tunnel model is configured to simulate variable stiffness that may be employed both in the wing- fuselage attachments area and in the wing structural box itself. The model's aeroelastic response to changes in the aileron CS deflection is measured over a range of dynamic pressures at two different stiffnesses. The results obtained from this series of tests are used to evaluate the control potential of variable stiffness. Results indicate beneficial