基于复合材料叠堆圆管的多谐圆柱阵换能器研制

Transducer is a kind of device for transmitting and receiving sound wave, it is applied abroad in underwater detecting, communication, navigation, mapping and so on. It's bandwidth and beamwidth are important parameters affecting it's applications. Seeking broader bandwidth and beamwidth are research hotspots all the time. There are two kinds of transducers with broad bandwidth now. One is composite transducer which has narrow beamwidth for it's composite sening element can only be shaped into a plane. The other one is multimode coupling transducer, it made from piezoelectric ceramic often taked a plane, sphere and cylinder shape. Althoug it has broader beamwidth when taked sphere and cylinder, but it's bandwidth is narrower than composite transducer. A noval technology, namely diceing ceramic-filling rubber- curving-dissolving rubber-pouring epoxy, has been developed in this project, which can be used to fabricate the composite with curved shape, such as arc plate and circular tube. A new type cylinder transducer with sening element of composite tubes stack is also developed in this project, it's bandwidth and beamwidth can be expanded by coupling vibration of composite tubes. The shortcoming of narrow beamwidth in current composite transducers can be overcomed by this kind of transducer. Now there is no research report about cylinder transducer with composite tubes stack.

换能器是一种声波收发器件，广泛用于水下探测、通讯、导航、测绘等。它的频带宽度及波束指向性直接影响其性能，探求更宽的频带以及更广的波束开角一直是换能器研究的主要问题。目前的宽带换能器主要有复合材料和多模耦合两类，现有的复合材料换能器由于工艺的限制只能成型平面状结构，使其波束开角受到限制，而多模耦合的换能器大多采用陶瓷敏感元件，虽然通过其球形或柱形的结构可实现较大的波束开角，但其带宽不及复合材料。本项目针对现行宽带换能器存在的缺陷，提出采用切割陶瓷-填充橡胶-成形曲面-溶蚀橡胶-浇注环氧的新技术，实现压电复合材料的曲面成型，制备复合材料圆管或圆弧；项目同时还提出采用不同厚度的复合材料圆管叠堆构成敏感元件，研制新型的圆柱阵换能器，以拓展换能器带宽并实现水平全向的波束开角。该结构换能器目前未见有报道，它可兼有宽带及大波束开角的特点，弥补现有换能器的不足。

项目以拓宽换能器频带和波束开角为研究目的，采用低机械品质因数（Q值）复合材料结合多模振动耦合拓展换能器带宽；通过切割陶瓷—填充橡胶—压模曲面—浇注环氧的新技术制备复合材料管形敏感元件以扩展换能器波束开角；采用两复合材料圆管套叠实现双模耦合，研制宽带、大波束开角柱形换能器样机。通过研究项目建立了换能器叠堆圆管振动频率的设计模型，以及叠堆圆管振子带宽扩展的设计依据，通过仿真两叠堆圆管的厚度之差与振子带宽之间的变化关系，完成复合材料圆管叠堆压电振子设计。通过实验，开发建立了曲面压电复合材料的制备工艺，制备出复合材料圆管叠堆振子——换能器敏感元件，并应用该元件制作完成叠堆圆管换能器样机。样机的性能达到：发射电压响应157dB，带宽85kHz，水平指向（-6dB）波束开角270°。测试结果充分验证了复合材料叠堆圆管拓展带宽的有效性。项目研究的相关技术获7项国家发明专利授权，申请了3项国家发明专利；研究成果发表论文17篇，其中SCI检索9篇，EI检索3篇。