长轴加长型宽带弯张换能器

Ⅳ型弯张换能器的机械品质因数较高,带宽不宽。为改善其带宽性能,在椭圆管形弯张壳体的基础上,利用多模态耦合的原理,提出了一种长轴加长型弯张换能器。以新型弛豫铁电单晶铌镁酸铅——钛酸铅(PMNT)为驱动材料,利用有限元软件ANSYS对弯张换能器进行了设计分析并制作了换能器样机。测量得到在1.6~16 kHz的频率范围内,换能器的最大发送电压响应136dB,响应起伏7.8 dB。理论分析与实验结果表明,与Ⅳ型弯张换能器相比,长轴加长型弯张换能器在保持频率低,响应高等优点的同时,显著拓宽了弯张换能器的带宽。

Broadband flextensional transducer with major axis lengthened

The bandwidth of the Class IV flextensional transducer is narrow for its high mechanical quality factor. For improving its bandwidth capability, a flextensional transducer with major axis lengthened is proposed by the theory of nmltiple-mode-coupling based on the oval shell. The transducer driven by novel relaxor ferroelectric single crystal lead magnesium niobate-lead titanate (PMNT) is designed and analysed using finite element software ANSYS and a prototype of the transducer is developed. The transmitting voltage response of the transducer reaches to 136 dB with ripple 7.8 dB from 1.6 kHz to 16 kHz. Based on the theoretical analysis and experimental results, it proves that the flextensional transducer with major axis lengthened has a much broader bandwidth than the Class IV flextensional transducer combing with the advantages of low frequency and high response.