Research On Anti-ferroelectric Ceramics Flextensional Transducer

At present,the application of active sonar to detect submarines has become a mainstream,the further implementation on the lowfrequency,the high power,the broadband emission of acoustic transducers becomes the focus in the designers.Type IV flextensional transducer is a common lowfrequency,high power transducer,whoseactive materialsare piezoelectric ceramics usually.Compared with piezoelectric ceramics,the eletro induced strain of anti-ferroelectric ceramics(PLZST)should be larger.Anti-ferroelectric ceramics can effectively improve performance indexs of transducers,such as transmitting voltage response.The main work of this paper is to use the new materialanti-ferroelectric ceramics to study,design and producewater drop type flextensional transducer.This paper fistly puts forward the shell structure of water drop type flextensional transducer to inspire the first asymmetric bending mode and puts forward the idea of expanding flextensional transducer's bandwidth by coupling the first asymmetric bending mode and the first bending mode.First,this paper introduced the energy conversion mechanism,operation mode and theoretical analysis of nonlinear electromechanical couplingof thenew materialanti-ferroelectric ceramics material.And the determination of PLZST anti-ferroelectric ceramics' material parameters was introduced.Then,this paper presents the new structure of water drop type flextensional transducer,which can expand the bandwidth of the transducer.The design and optimization of the anti-ferroelectric ceramics water drop type flextensional transducer are introduced.Concretely,the finite element models of transducer are established by ANSYS.The effect of shell size on frequency characteristics and response characteristics are obtained by air analysis and water analysis.According to the law,the size of the prototype is determined by optimizing.And the performance of the water drop type flextensional transducer with the same size of the prototypeand different materials is analyzed.The frequencies of the first two modes of the are 1260 Hz and 2220 Hz.In the frequency range from 1.08 Hz to 2.52 Hz,the maximumfluctuation of transmittingvoltage response is 6.4dB.Finally,the result of prestressing analysis is obtained.And the prototype is manufactured and tested.The results show that water drop type flextensional transducer can stimulate the first asymmetric bending mode.The bandwidth of the transducer is expanded by coupling of the first asymmetric bending mode and the first bending mode.