Influence of backing compliance on transducer performance

Abstract

This paper presents a simple one-dimensional model for describing the influence of backing impedance on the performance of sensors and projectors. It uses a center-of-mass model, where the influence of backing can be largely extracted into a separable term. As an example, it includes consideration of the familiar underwater case of an air-backed steel plate with an outer compliant (decoupler) coating. This approach is principally useful in large numerical structural acoustical studies, where the use of complete transducer formulations would become computationally impractical.

A Transfer Matrix Approach for Acoustic Analysis of a Multilayered Active Acoustic Coating

“…Photiadis et al [8] presented a simple centre-of-mass representation (SCMR) for a double-layer actuator, which can provide a direct view of the actuator operation. Furthermore, the authors extended this technique to study the in#uence of backing compliance on the performance of surface mounted actuator [9] and to predict the acoustic characteristics of each transducer component [10].…”

A technique for modelling multiple piezoelectric layers

“…A simple centre-ofmass representation (SCMR) for a double-layer actuator was presented [14]. Furthermore, the authors extended this technique to study the influence of backing compliance on the performance of a surface-mounted actuator [15]. The use of piezoelectric materials in making smart acoustically active surfaces was demonstrated [16].…”

Development of a broadband underwater sound projector

“…the individual layer frequency of 196 kHz. This is an indication that the individual rods in the [1][2][3] piezocomposite layers have been well aligned on top of each other such that characteristics of the single layer are not present. There is a mode present in the 30 kHz to 40 kHz region which was first noticed when the backing mass was attached onto the piezocomposite sandwich.…”

“…Fig. 2 shows an analytical plot of the influence of the thickness of a tungsten backing plate as computed using a 1-D wave propagation model [2]. It was determined that since the overall weight of the projector was NOT an issue, that the 0.5-inch tungsten backing should provide +5 dB gain, however, it should also be noted that if weight was of concern, then a 0.25-inch thick tungsten backing should provide greater than +4 dB gain ( Fig.…”