Modeling and study of the quasi-static behavior of piezoceramic telescopic actuation architectures

Piezoelectric stacks are often used in smart structures applications that demand large forces. However, there are numerous applications that require slightly more displacement than is available from stacks, and the performance requirements allow room for some force to be sacrificed to obtain this displacement. A new type of piezoelectric actuation architecture, referred to as telescopic, was designed to meet the need for moderate displacement amplification (up to 20 times) while still producing large forces. This architecture internally leverages the piezoelectric strain by a series of cascading shells uniquely connected by end caps such that the shells "telescope" out when activated. This paper presents an analytical model to predict the force-deflection behavior of this actuator with compliant end caps. To aid in evaluating this new architecture, the losses due to architectural features such as end caps, gap size, number of shells, and constant thickness/area are presented along with a comparison to the current state of the art.