近周期声子晶体开孔结构的大辐射面夹心式纵振换能器的优化研究

Optimization of a sandwich longitudinal vibration transducer with a large radiation surface based on hole structure of nearperiodic phononic crystal

大尺寸夹心式纵振压电陶瓷换能器中径向振动的存在不仅会导致换能器纵向辐射声功率的降低,还会缩短换能器的使用寿命,严重影响其性能和可靠性.为了减少大尺寸换能器中纵、径振动之间的强烈耦合,保证较高的纵向工作效率和可靠性,克服工作带宽较窄、振幅分布均匀度较差、位移振幅较小的缺陷,本文基于多点变形缺陷近周期声子晶体结构对大尺寸夹心式纵振压电陶瓷换能器进行了优化.利用仿真软件对优化后的换能器的性能指标进行了模拟分析,并进行了实验验证.结果表明,基于多点变形缺陷近周期声子晶体结构的大尺寸压电陶瓷换能器的纵向振动模态更加单一,可以有效提高大尺寸换能器辐射面的位移振幅和振幅分布均匀度,拓宽工作带宽.

The existence of radial vibration in a large-dimension sandwich longitudinal vibration piezoelectric ceramic transducer will reduce the longitudinal radiated sound power and shorten the service life of the transducer,which seriously affects its performance and reliability.To reduce the strong coupling between longitudinal and radial vibration,ensure high longitudinal working efficiency and reliability,and overcome the disadvantages of narrow working bandwidth,poor uniformity of amplitude distribution,and small displacement amplitude,the large-dimension sandwich longitudinal vibration piezoelectric ceramic transducer is optimized through machining several periodic holes on the front cover plate of the transducer to form a multi-point deformation defect structure.In this study,the simulation software is used to simulate and analyze the performance index of the optimized transducer,and the optimization effect is verified through experiments.The results show that the large-dimension piezoelectric ceramic transducer based on a multi-point deformation defect near-periodic phononic crystal structure has a single longitudinal vibration mode,which can effectively improve the displacement amplitude and amplitude distribution uniformity of the radiation surface of a largedimension transducer and broaden the transducer’s working bandwidth.