Solid State High Authority Telescoping Actuators.

摘要

Stacks are one of the most commonly used form of piezoelectric actuation; unfortunately, they provide small displacements and as the stroke requirement grows so does the length of the stack. For many applications with small volume sizes, stacks are not viable due to their packaging size and if too long can pose a buckling risk. Fortunately, while many of these applications require more stroke, typically factor of 2 to 15 more than a stack, the force requirement is typically less than that generated by a stack, leaving room for amplification techniques. While there are several external techniques, they experience severe losses% leading to a great reduction in work efficiency. The goal of this research effort was to develop a family of high authority actuators ranging in size from the submillimeter scale, for embedment in composite structures, to discrete actuators up to the centimeter scale, that could provide modest stroke amplification (2 to 15 times) in a compact package with minimal force reduction. A solid state, monolithic piezoelectric actuation architecture was developed that internally leverages the piezoelectric strain by a series of cascading shells uniquely connected by end caps such that the shells 'telescope' out when activated. The tailorability of the displacement output of this actuator design permits much more efficient coupling of the actuator output into a loading profile of similar impedance and thereby much greater effective actuator output. This research consisted of the four specific tasks: (1) Manufacturing development and process modeling, (2) Actuator performance modeling, (3) Experimental component testing and (4) Performance analysis and evaluation. In this report, the methodologies employed and the results obtained are summarized for each of these tasks, for more detailed development the reader is referred to the papers in Appendix B.