Design, development, and testing of a transonic missile fin employing PBP/DEAS actuators

Abstract

This paper describes a new class of flight control actuators using Post-Buckled Precompressed (PBP) piezoelectric elements mounted within a transonic missile fin. These actuators are designed to produce significantly higher deflection and force levels than conventional piezoelectric actuator elements. Classical laminate plate theory (CLPT) models are shown to work very well in capturing the behavior of the free, unloaded elements. A new high transverse deflection model which employs nonlinear structural relations is shown to successfully predict the performance of the PBP actuators as they are exposed to higher and higher levels of axial force, which induces post buckling deflections. A 6 (15.2cm) square rounded diamond transonic fin was made with integral PBP actuator elements. Quasi-static bench testing showed deflection levels in excess of ±7° at rates exceeding 21 Hz. The new solid state PBP actuator was shown to reduce the part count with respect to conventional servoactuators by an order of magnitude. Power consumption dropped from 24W to 1.3W, slop went from 1.6° to 0.02° and peak current draw went from 5A to 18mA. The PBP actuator was wind tunnel tested and shown to possess no flutter, divergence or adverse aeroelastic coupling characteristics.