The Radial Vibration Analysis Of Composite Transducer With Functionally Graded Layers

In the underwater sound and ultrasonic technology, the transducer is one of the key components. It is an energy transformation device. The piezoelectric ceramic thin rings are common form in the piezoelectric devices. Functionally graded materials (FGMs) are a special kind of inhomogeneous materials, of which the material property varies continuously in spatial position. Comparing with the traditional laminated composite materials, such materials possess good properties.Many transducers work in extensional vibration mode. The dynamic behavior of a circular cylindrical composite piezoelectric transducer(CPT) operating in radial vibration mode is investigated. The CPT is composed of an elastic ring and a piezoelectric ring polarized in the radial direction. Based on the three-dimensional linear elasticity and piezoelectricity theories, the governing equations for plane stress state problem under the harmonic excitation are derived and the general solutions for both piezoelectric and elastic rings are obtained. The characteristic equations for resonant and anti-resonant frequencies are established. The presented methodology is fit to carry out the parametric investigation for composite piezoelectric transducers (CPTs) with arbitrary thickness in radial direction. In this investigation, the property of the materials is assumed to vary in power-law form along the radial direction. With the aid of numerical analysis, the relationships between the dynamic behaviors of the cylindrical CPT and the material inhomogeneity index as well as the geometric parameters of the CPTs are illustrated graphically and some important features are reported.