Development of a Composite Bendable-Wing Micro Air Vehicle

Abstract

This paper describes the development of a bendable-wing Micro Air Vehicle (MAV) which is capable of being packed in a minimal volume. The wing is rigid under normal flight loads but compliant when the force is reversed, allowing it to be bent into a small diameter. The bendable-wing technology was developed to accommodate packing requirements on several larger vehicles, but was explored further in the creation of an endurance aircraft for use in the 2006 International Micro Air Vehicle Competition. The design procedure entailed airframe and wing design, component selection and placement, and composite stress analysis on the bendable wing. Stress analysis led to the choice of ±45° fiber orientation on the bendable-wing. Manufacturing was aided by custom CAD software and automated machining. Wind tunnel testing and flow visualization were used to show that flow separation is significant at low angles of attack of the thin under-cambered MAV wing. Visual Image Correlation indicated that a maximum permanent deformation of less than 0.5 mm was present after the wing was removed from the storage container. Qualitative flight testing confirmed that the observed residual wing deformation did not hinder flight and verified that the aircraft could consistently complete the objectives of the endurance mission.