Study On The Performance Of High Frequency Wide Beam Piezoelectric Composite And Transducer

The 1-3 spherical crown piezoelectric composite not only inherits the advantages of low acoustic impedance,high transient response and large electromechanical coupling coefficient,but also can launch large open angle and wide beam in horizontal and vertical direction under high frequency emission.In this paper,a finite element model is used to study the correlation between the structural parameters of a 1-3 spherical piezoelectric composite and its harmonic response and vibration mode,and the results are verified by the experiment.The results show that the experimental results can effectively verify the finite element results.With the increased PZT volume fraction,the relative permittivity and the piezoelectric strain constant d₃₃ of composites increase gradually,the dielectric loss and the g₃₃ gradually decrease,while the resonance frequency and the peak conductance peak of the vibration point all increased.With the increased PZT aspect ratio,the relative dielectric constant of the 1-3 spherical crown piezoelectric composite decreases gradually,and the dielectric loss increases gradually,but the change of piezoelectric and resonance frequency is weak.The dielectric and piezoelectric properties and resonance frequencies of the 1-3 spherical crown piezoelectric composite are not affected by the number of PZT elements,but the increased number of basic elements makes the peak value of the conductivity increased.In the ambient temperature range of-20^oC-60^oC,the vibration mode of the1-3 spherical piezoelectric composite has no change,indicating that it has good temperature stability.When the plating temperature is 40 ^oC and the plating time is 9min-11 min,the surface electrode of the piezoelectric composite coating is the most compact and uniform,the thickness of the electrode is the most suitable and the performance is the best.A finite element model for the 1-3 spherical crown transducer is established and the correlation between its structural parameters and its directivity and the response performance of the emission voltage is studied.The results are verified by experiments.The results show that the directional angle of the 1-3 spherical crown transducer is far greater than that of the plane underwater transducer,and it can launch a large open angle and wide beam in both horizontal and vertical directions.With the increased PZT volume fraction,the angle in horizontal and vertical direction and the peak of the response to the emission voltage increases gradually.When the PZT volume fraction is 70.6%,the opening angle and the emission voltage response peak of the underwater acoustic transducer-3 dB reach to the maximum,and the performance is the best.The PZT aspect ratio has little influence on the directivity of the transducer,and the angle directivity of the acoustic transducer level and the vertical direction-3 dB is greater than the 30^o.When PZT aspect ratio is 0.57,the directivity of the transducer is the best.The response curve of the emission voltage is the most stable...