Aeroservoelastic DAP missile fin development

Abstract

The development of an active aeroservoelastic missile fin using directionally attached piezoelectric (DAP) actuator elements is detailed. Several different types of actuator elements are examined, including piezoelectric polymers, piezoelectric fiber composites and conventionally attached piezoelectric (CAP) and DAP elements. These actuator elements are bonded to the substrate of a torque plate. The root of the torque plate is attached to a fuselage hard point or folding pivot. The tip of the plate is bonded to an aerodynamic shell which undergoes a pitch change as the plate twists. The design procedures used on the plate are discussed. These include an optimization of the actuator element orientation, substrate material type and thickness, as well as a determination of the optimum elastic axis location. A comparison of the various actuator elements shows that DAP elements provide the highest deflections with the highest torsional stiffness. A torque plate was constructed from 0.2032mm thick DAP elements bonded to a 0.127mm thick AISI 1010 steel substrate. The torque plate produced static twist deflections in excess of ±3º. An aerodynamic shell with a modified NACA 0012 profile was added to the torque plate. This fin was tested in a wind tunnel at speeds up to 50ms-1. The static deflection of the fin was predicted to within 6% of the experimental data.