Cymbal piezocomposite transduser designs and acoustic applications

The effects of changes in materials and dimensions on the cymbal-typeflextensional transducers, in water-loaded and in air were examinedexperimentally and through finite-element-analysis (FEA). After gainingexperience and confidence in the FEA models, extensive parametric studies wereperformed using FEA to investigate the size and material effects on cymbalunderwater transducer characteristics and pressure dependence. The failure modein cymbal transducers under hydrostatic pressure is described. Cavity beneath theendcaps of the cymbal transducer was partially filled with polymeric media tocause visco-elastic damping in order to reach higher bandwidth. In addition,feasibility of cymbal transducer for air acoustic applications was investigated.Adjusting the dimensions and materials used for drivers and endcaps providesa range in the fundamental flexural frequency from about 3 to 250 kHz in water.The scaling factor, cavity depth, and PZT thickness had the strongest effects onthe projector/receiver performance (TVR/FFVS). It was found that cavity depthand endcap material have a very strong effect on the stability of underwatersensitivity and pressure tolerance of these devices. Initial studies showed thatbandwidth of the cymbal transducer can be tuned to the desired value by fillingthe cavity beneath the endcaps with polymeric materials. Finally, it was showedthat the new air acoustic design of piezocomposite cymbal transducer posses veryhigh sound pressure level and it can be used in air acoustic applications.Keywords: Cymbal transducer, electroacoustic, Finite Element Analysis (FEA),optimization, piezoelectricity