Resonant frequency determination of a multistore high-altitude/long- endurance wing

It is desirable to predict the resonant frequencies and mode shapes of extremely high-aspect ratio wings for highaltitude/long-endurance applications. Such results give insight into structural response and serve as a precursor to flutter and gust response calculations. The influence of rigid body modes has been shown to be significant for the aeroelastic response of these aircraft, but this effect is frequently not captured in a laboratory setting. Additionally, resonant frequencies can be difficult to predict when multiple discrete masses such as engines or mission pods are distributed along the span. In this work, the resonant frequencies of a high-altitude/long-endurance wing mounted on a spring of variable stiffness with both root and tip stores are determined analytically from classical beam theory. The model is then extended through a component-mode synthesis to incorporate multiple spanwise masses of any discrete distribution. Computational results are compared with an experiment, and good agreement is shown.

Duke Scholars

Author Earl H. Dowell Thomas Lord Department of Mechanical Engineering and Materia ...