大功率夹心式压电换能器结构参数计算分析及设计

基于一维纵振理论和机电等效原理,得到了单匹配层夹心式压电换能器辐射声压级的计算公式,通过该公式对换能器结构参数对其谐振频率和辐射声压级(sound pressure level,SPL)的影响进行了计算分析。计算结果表明:换能器径向尺寸对谐振频率的影响不大,但前盖板径向尺寸的增大会提高辐射声压级;纵向尺寸的增大会使换能器系统谐振频率降低,但增加前盖板厚度,或增大前后盖板厚度比,有利于辐射声压级的提高;增加压电晶片的片数、厚度和面积都可使换能器辐射声压级提高;换能器发射端增加匹配层能有效提高辐射声压级,匹配层的厚度和密度对声压级幅值和带宽有影响。依据计算结果,进行了给定指标要求的换能器的设计计算。

Design and structural parameters calculation analysis of a high power sandwich piezoelectric transducer

Based on the one-dimensional longitudinal vibration theory and the electromechanical equivalent principle,the calculation formula of the radiated sound pressure level(SPL)of a single matching layer sandwich piezoelectric transducer was obtained.The influence of the structural parameters of the transducer on resonant frequency and radiated SPL was calculated and analyzed.The calculation results show that the radial dimension of the transducer has little effect on the resonant frequency,but the increase of the radial dimension of the front cover increases the radiated SPL.The increase of the longitudinal dimension reduces the resonant frequency of the transducer system,but the increasing of the thickness of the front cover plate or the thickness ratio of the front and back cover plates is beneficial to the improvement of the radiation SPL.The increase of the number,thickness and area of the piezoelectric ceramic piece will improve the SPL of the transducer.Adding matching layer at the transmitting end will effectively improve the radiated SPL.The thickness and density of the matching layer have an influence on the amplitude and bandwidth of the SPL.According to the calculation results,the design calculation of the transducer required for a given index is performed.