POST-BUCKLED PRECOMPRESSED TECHNIQUES IN ADAPTIVE AEROSTRUCTURES: AN OVERVIEW

An overview of the development and application of postbuckled precompressed (PBP) piezoelectric actuators is presented. It has been demonstrated that PBP actuators outperform conventional piezoelectric actuators by relying on axial compression to counter the inherent stiffness in the actuator element. In doing so the mechanical work output has been shown to increase three-fold compared to conventional bimorph actuators. Actuator stroke has been demonstrated to increase up to 300% without compromising the blocked force capability This results in an expansion of the design space of piezoelectric bender elements and makes them excellent candidates for substituting conventional electromechanical flight control actuators. Successful application of PBP elements can be found in unmanned aerospace systems ranging from subscale vertical-take-off-and-landing vehicles to supersonic missile fins. With respect to conventional electromechanical servoactuators it is demonstrated that PBP actuator elements induce a lower systems weight fraction, a substantially higher bandwidth, and an order of magnitude lower power consumptions and part count.