双椭圆壳串联宽带弯张换能器

Dual elliptical shells serially connected broadband flextensional transducer

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。

A new flextensional provided. The transducer＇s shell transducer with advantages of low frequency, broadband and high output power is is serially connected by two elliptical class IV flextensional shells along the major axis, and driven by two long piezoelectric ceramic stacks inside. With the help of finite element software, a sample whose bandwidth is broadened by coupling the first three flexural modes and the composite mode of driver＇s longitudinal mode and shell＇s membrane mode is designed. The sample＇s transmitting voltage response is more than 128.5 dB and the sound level is more than 190 dB from 1.4 kHz to 6.0 kHz. The tested results reveal that this new transducer not only has a broader bandwidth compared to the traditional class IV flextensional transducers which utilize the first flexural mode only, but also fulfills the requirements of low frequency and high power.