阻抗和厚度梯度变化准周期结构水下声学特性研究  

A study on underwater acoustic characteristics of quasi-periodic structure based on gradient change of impedance and thickness

作　　者：杜逸眉 胡博[1,2,3] 李明杰 时胜国 时洁[1,2,3] DU Yimei;HU Bo;LI Mingjie;SHI Shengguo;SHI Jie(College of Underwater Acoustic Engineering,Harbin Engineering University,Harbin 150001,China;Acoustic Science and Technology Laboratory,Harbin Engineering University,Harbin 150001,China;Key Laboratory of Marine Information Acquisition and Security,Ministry of Industry and Information Technology,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]哈尔滨工程大学水声工程学院,哈尔滨150001 [2]哈尔滨工程大学水声技术重点实验室,哈尔滨150001 [3]哈尔滨工程大学,工业和信息化部,海洋信息获取与安全工信部重点实验室,哈尔滨150001

出　　处：《振动与冲击》2023年第4期212-218,255,共8页Journal of Vibration and Shock

基　　金：国防项目(6142109200101);湛江市创新创业团队引育“领航计划”项目(211207157080994);国家自然科学基金项目(52171333)。

摘　　要：周期结构在减振降噪、滤波等方面具有很大的应用潜力。功能梯度材料是近年出现的具有优良性能的新型复合材料。为了满足水下低频宽带应用的要求,将周期结构和功能梯度材料相结合,提出了厚度和阻抗梯度变化的准周期结构。利用传递矩阵法,对厚度和阻抗梯度变化的准周期结构进行了反射系数的仿真,与周期结构带隙特性进行了比较,分析了厚度与阻抗对准周期结构带隙的影响,最后根据仿真结果制备了试验样品,进行了水下验证试验。研究结果表明,厚度和阻抗梯度变化的准周期结构,第一带隙具有更低的起始频率与更高的截止频率,阻抗梯度变化对准周期结构带隙特性的影响大于厚度梯度变化。研究结果可为利用准周期结构实现水下低频宽带的减振降噪提供参考。A periodic structure has great application potential in vibration and noise reduction, filtering, etc. Functionally graded materials(FGMs) are novel composite materials with excellent properties in recent years. Periodic structures were combined with functionally graded materials in this work. A quasi-periodic structure with gradient changes of thickness and impedance was proposed to meet the requirements of underwater low-frequency broadband applications. Firstly, the reflection coefficient of the quasi-periodic structure with gradient changes of thickness and impedance was simulated using the transfer matrix method. The band gap characteristics of the quasi-periodic structure and the periodic structure were compared, and the influence of thickness and impedance on the band gap of the quasi-periodic structure was analyzed. Finally, experimental samples were prepared and underwater verification experiments were carried out. Results show that the first band gap of the quasi-periodic structure with gradient change of thickness and impedance has a lower starting frequency and a higher cutoff frequency. The impedance gradient change has greater effect than the thickness gradient change on the band gap characteristics of the quasi-periodic structure. These results can provide reference for quasi-periodic structure application on vibration and noise reduction of underwater low-frequency broadband.

关 键 词：阻抗 梯度变化 周期结构 减振降噪 

分 类 号：O427.5[理学—声学] O482.1[理学—物理]