Terfenol-D鱼唇式弯张换能器

提出了一种“鱼唇式”弯张换能器的设计方案,采用变高度椭圆壳体,这样的壳体兼有振幅放大和高度加权放大的“双重放大”作用,并设计制作了Ｔｅｒｆｅｎｏｌ－Ｄ“鱼唇式”弯张换能器。理论分析和湖上实验结果表明,Ｔｅｆｅｎｏｌ－Ｄ“鱼唇式”弯张换能器,具有较低的谐振频率,水中约为 １．１ｋＨｚ左右;较宽的频带,－３ｄＢ带通 Ｑ值低于 ３;发射电流响应为 １８２ ｄＢ;采用了溢流腔填充顺性材料可获得较大的工作深度．     

800Hz Terfenol-D鱼唇式弯张换能器

本文研制了800Hz Terfenol-D鱼唇式弯张换能器，换能器设计中采用永磁偏磁场和能有效抑制涡流损耗的闭合磁路结构，最高声源级185dB，-3dB带宽180Hz,这种鱼唇工弯张换能器克服了连续直流提供偏磁场时发热强的缺点，并且仅需要普通的功率放大器，更适于长时间连续工作，使这一新型低频大功率水声换能器趋于实用化。     

四边型弯张换能器特性研究及宽带设计

四边型弯张换能器通常工作带宽较窄,为了提高带宽性能,对四边型弯张换能器振动及辐射特性进行了研究,重点分析壳体结构参数对换能器发送电压响应的影响。根据分析结果提出了拓宽换能器工作带宽的方法,利用有限元软件进行了仿真计算并制作了四边型弯张换能器样机。测量得到在2.4~5 kHz的频率范围内,换能器的最大发送电压响应值达到140 dB,带内起伏4 dB,有限元仿真结果与实验结果吻合较好。研究结果表明设计的四边型弯张换能器不仅能够低频工作,并且可以在小尺寸下实现大功率发射,同时还具备宽带发射特性。      

叠合结构超低频弯张换能器

研究了一种将多个椭圆弯张壳体在短轴方向进行机械叠合的超低频弯张换能器,每个弯张壳体采用超磁致伸缩材料进行驱动。推导了多个叠合壳体的等效电路,利用支路阻抗方法得到了换能器频率和阻抗的方程表达式。针对多个壳体叠合的结构复杂性,采用有限元方法计算并分析了叠合壳体换能器的多个结构点的振动位移分布,通过平动位移分布设计了活塞辐射面的结构参数。将有限元方法计算的换能器在空气中和水中的谐振频率与等效电路法计算的结果进行了对比,符合较好。研制了6个壳体叠合的超低频弯张换能器样机,换能器外形尺寸为Φ230×630 mm,重量为39 kg。换能器经湖上试验,水中谐振频率130 Hz,最大发送电流响应161.1 dB,最大发射声源级为180.4 dB,实现了超低频、小尺寸的发射能力。      

自由端盖Ⅲ型宽带弯张换能器的设计

提出了一种利用多模耦合实现低频、宽带、大功率特性的新结构Ⅲ型弯张换能器。通过在压电陶瓷堆内部嵌入与凹型弯张壳体相连的弹性辅助弯曲梁结构,并用弯曲圆盘作为顶部自由端盖,增加有效工作模态。利用有限元方法对换能器进行了设计优化,分析结果显示换能器在低频段存在4个主要工作模态。根据优化结果,加工制作了换能器样机,水池实验的测试结果表明:在1.5～5.5 kHz范围内,换能器样机的发送电压响应均大于135 dB;1.5～4 kHz内的最大发送电压响应大于142 dB,响应起伏小于6 dB。研究结果表明自由端盖Ⅲ型弯张换能器不仅能够在小尺寸设计下实现大功率工作,还能获得低频宽带发射性能。      

Ⅳ型弯张换能器振动辐射特性分析

本文利用等效电路支路阻抗分析方法,研究了Ⅳ型弯张换能器振动辐射特性与换能器结构之间的关系,得出一系列对换能器设计有用的结论．     

Ⅳ型弯张换能器振动辐射特性分析

本文利用等效电路支路阻抗分析方法,研究了IV型弯张换能器振动辐射特性与换能器结构之间的关系,得出一系列对换能器设计有用的结论。     

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136 dB,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.     

变张换能器的等效电路支路阻抗分析方法

本文提出了适用于弯张换能器的等效电路支路阻抗分析方法,归纳总结了一些描述IV型弯张换能器振动辐射的特性参量,通过支路阻抗分析方法计算这些特性参量可以进行换能器局部结构的优化设计.     

弯张换能器的等效电路支路阻抗分析方法

本文提出了适用于弯张换能器的等效电路支路阻抗分析方法,归纳总结了一些描述IV型弯张换能器振动辐射的特性参量,通过支路阻抗分析方法计算这些特性量可以进行换能器局部结构的优化设计。     

Broadband transducer with tube-beam coupling structure

A broadband transducer with tube-beam coupling structure is presented. Flexural beams are put into a traditional segmented ring transducer including inactive portions to form a new tube-beam coupling structure with more useful working modes. Using multiple-modecoupling design technique, the bandwidth of transducer could be expanded efficiently towards low frequency range. The optimization study of the electroacoustic parameters is carried out by finite element analysis at first. Then a prototype is manufactured and measured. It is shown that this projector combines the fine qualities of flextensional transducer with those of circular ring transducer by both the simulated and experimental results. It could achieve low frequency,high power and wide band performance from compact size. In addition, it is suitable for deep submergence operation when using free-flooded design.     

管梁耦合宽带换能器

对一种管梁耦合宽带换能器进行了研究,通过在圆环换能器中加入弯曲梁组成管梁耦合结构,增加有效工作模态,利用多模谐振耦合优化设计,可使换能器的工作带宽向低频大幅扩展.理论计算与实测结果均表明,管梁耦合换能器具备频带宽、功率大、尺寸小、深水性能好等特点,兼具圆环换能器与弯张换能器的优势,工作性能优良,设计灵活多变.      

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 performance,a flextensional transducer with major axis lengthened was proposed by the theory of multiple-mode-coupling based on the oval shell.The transducer driven by novel relaxor ferroelectric single crystal lead magnesium niobate-lead titanate(PMNT)was designed and analysed using finite element software ANSYS and a prototype of the transducer was developed.The transmitting voltage response of the transducer reaches to 136 dB with fluctuation 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 ClassⅣflextensional transducer combing with the advantages of low frequency and high response.     

A wideband combined transducer for measuring system in sound tube

A wideband transducer for sound tube system is presented,which combines longitudinal transducer and ClassⅣflextensional transducer to improve the performance at low frequency and broaden the working band.The equivalent circuit is obtained and used to analyze the coupling mechanism between longitudinal transducer and flextensional transducer.A prototype of the transducer is developed after optimizing the electro-acoustic performances by Finite Element Method.The standing wave in the sound tube stimulated by this transducer has been studied and the sound absorbing coefficients of two acoustic materials samples are measured using this sound tube,which shows that the transducer can meet the requirements of acoustic material measurement with the working band ranging from 1.4 kHz to 23 kHz.     

Optimization of structural variables of a flextensional transducer by the statistical multiple regression analysis method

The performance of an acoustic transducer is determined by the effects of many structural variables, and in most cases the influences of these variables are not linearly independent of each other. To achieve optimal performance of an acoustic transducer, we must consider the cross-coupled effects of its structural variables. In this study, with the finite-element method, the variation of the operation frequency and sound pressure of a flextensional transducer in relation to its structural variables is analyzed. Through statistical multiple regression analysis of the results, functional forms of the operation frequency and sound pressure of the transducer in terms of the structural variables were derived, with which the optimal structure of the transducer was determined by means of a constrained optimization technique, the sequential quadratic programming method of Phenichny and Danilin. The proposed method can reflect all the cross-coupled effects of multiple structural variables, and can be extended to the design of general acoustic transducers.     

双椭圆壳串联宽带弯张换能器

提出一种利用多模态耦合的低频、宽带、大功率的新型弯张换能器,其结构上将两椭圆的Ⅳ型弯张壳体沿长轴方向串联为一体,两组长压电陶瓷堆贯穿其中驱动。利用有限元软件设计并制作一款此新型换能器的样机,其工作频带通过耦合壳体前三阶弯曲模态及压电陶瓷堆纵振模态与壳体膜模态的复合模态展宽。经测试在1.4~6.0 kHz范围内,样机的发射电压响应大于128.5dB,声源级大于190dB。结果表明,此弯张换能器与只利用一阶弯曲模态的Ⅳ型弯张换能器相比不仅有更宽的工作带宽,还满足低频和大功率的声辐射要求。