磁致伸缩-压电混合激励超宽带Janus-Helmholtz换能器研究

The basic theory and key technologies of hybrid magnetostrictive-piezoelectric ultra wideband Janus-Helmholtz transducer would be studied systematically. A Janus transducer driven by the union of rare-earth giant magnetostrictive material and piezoelectric ceramic is used as the driving source of the new type transducer. Combined with the design of multi-cavity structure, the transducer would have more than three useful modes including longitudinal modes and liquid cavity resonant modes. Using multiple-mode-coupling design technique, the bandwidth of transducer would be expanded as much as possible. Moreover, a new nonlinear driving manner would be developed for the rare-earth giant magnetostrictive material to make full use of its potential performance which could produce greater sound power at lower frequency range and increase the electro-acoustical efficiency at the same time. The integrated analytical model of transducer would be established by the comprehensive use of equivalent circuit method and finite element method at first. Then both the characteristics of vibration and coupling principle of different working modes could be analyzed by the model. At last the overall structural design would be determined by the optimization analysis and the prototype of the new transducer would be manufactured and measured. The goal is to make the transducer achieve fine performances including low frequency, ultra wide band and high power within compact size for deep-sea applications. The main technical indexes are as follows: the first resonant frequency less than 500Hz, -6dB bandwidth over 2 octaves, maximum source level larger than 200dB, and working depth larger than 3000m.

对超宽带Janus-Helmholtz换能器的工作原理和关键技术进行系统研究。采用稀土超磁致伸缩材料和压电材料混合激励的Janus纵振换能器作为激励源，结合多液腔结构设计，使换能器具有更多的有效工作模态。通过3个以上工作模态的耦合优化设计，最大限度展宽换能器的工作频带。稀土超磁致伸缩材料采用非线性驱动方式，最大限度发挥材料的性能优势，实现更好的低频大功率工作性能，同时提高电声效率。建立等效电路方法与有限元方法相结合的换能器综合分析模型，研究各振动模态振动辐射特性及相互耦合作用规律，经过结构优化设计后确定总体设计方案。研制换能器样品，实现集低频、超宽带、大功率、小尺寸、大深度等优良性能于一体的换能器理论与技术创新：基频谐振频率小于500Hz，-6dB带宽大于2个倍频程，最大声源级大于200dB，工作水深大于3000m。

对超宽带Janus-Helmholtz换能器的工作原理和关键技术进行了系统研究。采用稀土超磁致伸缩材料和压电材料混合激励的Janus纵振换能器作为激励源，结合多液腔结构设计，使换能器具有更多的有效工作模态。通过3个以上工作模态的耦合优化设计，最大限度展宽换能器的工作频带。稀土超磁致伸缩材料采用非线性驱动方式，最大限度发挥材料的性能优势，实现更好的低频大功率工作性能，同时提高电声效率。建立了等效电路方法与有限元方法相结合的换能器综合分析模型，研究各振动模态振动辐射特性及相互耦合作用规律，经过结构优化设计后确定了总体设计方案。研制了2台换能器样品，实现了集低频、超宽带、大功率、小尺寸、大深度等优良性能于一体的换能器创新。