Abstract
Performance of piezoelectric underwater acoustic transducers have been studied by various researchers leading to various transducer design topologies which are intended to provide effective performance for variety of objectives. Fundamentally, the characteristic parameters of piezoelectric ceramic material affect the transducer’s performance. Even though operational characteristics (such as bandwidth, operational depth, etc.) of various transducer designs are known, less is known about the effect of environmental conditions such as pressure or stress and drive level on transducers and their corresponding effects on the operational characteristics of transducers. Transducers used in Sound Navigation and Ranging (SONAR) systems in naval and marine environments are typically subjected to sometimes extreme conditions which includes great depths, varying temperatures, and long duration. These environmental and operating conditions can adversely impact the performance of transducers. Subjecting different piezoelectric (soft/hard) ceramics to different directional stresses is not always deleterious. This research shows an increase in performance and corresponding parameters of piezoelectric ceramics, and their corresponding effect on performance of underwater acoustic transducers can be achieved by prescribed pre-stress treating piezoelectric elements. and the stability and utility of this modification depends greatly on the particular transducer design. Dynamic impedance measurements were used to investigate the extent of changes in parameters of piezoelectric ceramic materials (such as coupling coefficient, piezoelectric constant, dielectric constant, compliance constant and mechanical quality factor) when piezoelectric cylindrical and spherical acoustic transducers are subjected to environmental and operating conditions. A model has also been implemented that takes into account dependencies of environmental and operating conditions of various shapes of Lead Zirconium Titanate PZT transducers and predicts the estimated performance results of the transducers that includes; bandwidth, power factor, Transmit Voltage Response TVR, Sound Pressure Level SPL, output impedance as well as an estimation of both series and parallel tuning inductance required to achieve an optimum efficiency.