Modeling Piezoceramic Twist Actuation in Single-Cell Anisotropic Torque Box of Low-Observable UAV Wing

<p>The reduction of an aircraft's radar cross section can increase its survivability in hostile airspace by making it more difficult to locate and track by enemy radar. Replacing articulated flight control surfaces with adaptive controls will reduce surface discontinuities and enhance low observability. Actuation of the aerodynamic surfaces is achieved by an electric field applied to PZT actuators embedded in the top and bottom skins creating differential strain and shear in the host substrate. This creates torsion about the elastic axis and a change in the wing lift coefficient. The torsion of the designed baseline UAV's wing torque box was modeled in the presence of a full complement of air-loads by extending the Bredt-Batho theorem. This was accomplished through modifying Libove's method using a thin-walled linearly elastic fully anisotropic trapezoid cross-section beam. The linear tip twist angles due to a uniform cross-sectional moment were verified using the isotropic Bredt-Batho theorem and published anisotropic results by applying isotropic then anisotropic laminate elastic properties. The isotropic solutions were within 3.1%; the anisotropic results were within 6.9-10.9% of the published angles. The PZT actuation of the host structure was achieved by substituting the PZT-composite laminate elastic properties into the derived solution and inducing strain and shear of the PZT lamina by applying an electric field without the presence of external forces or moments. Using two different PZT laminae the angular twist as a function of the host lamina orientation angle and applied voltage was recorded.</p><p>This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact and remains as true to the original work as possible. Therefore you will see the original copyright references library stamps (as most of these works have been housed in our most important libraries around the world) and other notations in the work.</p><p>This work is in the public domain in the United States of America and possibly other nations. Within the United States you may freely copy and distribute this work as no entity (individual or corporate) has a copyright on the body of the work.</p><p>As a reproduction of a historical artifact this work may contain missing or blurred pages poor pictures errant marks etc. Scholars believe and we concur that this work is important enough to be preserved reproduced and made generally available to the public. We appreciate your support of the preservation process and thank you for being an important part of keeping this knowledge alive and relevant.</p>