Excitation of thin beams using asymmetric piezoelectric actuators

Abstract

In order to analyze the excitation of a complex beamlike structure comprised of arrays of piezoelectric actuators (that may not be arranged in symmetric pairs), it is necessary to determine the effect of a single asymmetric actuator. Using the superposition principle, the excitation of the entire structure can subsequently be analyzed. New analytical relations for the excitation of beams by a single piezoelectric element located on the surface of the beam (asymmetric excitation) were developed. A single asymmetric piezoelectric element when excited produces both flexural and extensional motion in a beam. The relations are used to study excitation of both flexural and extensional waves in beams using a pair of actuators as a function of: actuator length, relative voltage magnitude and phase, and frequency of excitation. The work presented here represents an important step because it is the analytical basis by which simultaneous active control of both flexural and extensional motion in flexible structures can be studied.