Design and modeling of surface bondable piezoelectric stack actuators for actuation of large structures

Abstract

In this work, the notion of using surface bondable piezoelectric actuators, which directly use the “33” electromechanical coupling, for actuating large structures is investigated. This concept was a result of the attempt to control the vibrations of a steel marine platform with piezoelectric actuators. Piezoelectric actuators find applications both in the excitations of membrane-like structures, wherein thin patches are bonded to the surface of the substructure to, and in the excitation of large structures, where piezoelectric stack actuators are conventionally employed akin to an electrodynamic exciter with stringer —to provide transverse loading. For the case of the actuation of the marine platform, the use of the piezoelectric stack actuators in a conventional manner could not be suggested for implementation on the actual structure due to its associated drawbacks. As an alternative, the concept of the surface bondable piezoelectric stack actuators was proposed. This design allows the stack actuators to be bonded to the surface of the structure (like a patch), and just like the patches, on the application of an external electric field would generate axial forces on the surface of the structure. In this study, the design of such an actuator is elaborated; following which, an analytical model is derived for beams with surface-bonded stack actuators. The analytical model is derived for the bending vibrations of the structure, and is used to investigate the necessity of the design and the actuation capability of the surface-bondable stacks. The actuation capability of the surface bondable stacks are compared with the actuation capability of other stack implementations, and with similar sized piezoelectric patches. Finally, experimental evidence is provided to demonstrate the practicality of the design.