新型声波器件的结构与性能研究

发布时间：2018-10-21 13:54

【摘要】：本文主要从事新型声波器件的结构与性能研究,全文共分为五章,除了第-章和第五章为绪论和总结与展望外,主要研究工作分为三个部分：(1)带基底声栅格结构超常透射的研究；(2)耦合共振系统双通滤波特性的研究；(3)种基于非线性碰撞的分谐频装置。各部分的简要内容如下：1.带基底声栅格结构超常透射的研究光波通过亚波长狭缝时会出现超常透射现象,声波也是这样。论文的第一章中简单介绍了声栅格结构超常透射的研究进展,相比于光栅格中的等离子体的激发,声栅格超常透射是由于栅格中横向耦合共振模式声波的激发。这种栅格结构的超构材料在声准直、单向传输等方面都有很好的应用。论文第二章,首先简单介绍了带基底声栅格结构的单向流通特性,并且指出这种单向透射是由于声波经栅格透射后重新分布为周期性源激发基底板的弯曲模式,从而辐射声波。随后通过栅格覆膜、改变栅格与覆膜间的填充液等方法对禁带频域内的声场透射效果进行增强。然后对声波非准直入射的透射效果进行研究,发现声波非准直入射后会出现负透射的效果,并给出了不同入射角度下出现负透射的声场传播图。最后,指出这种带基底声栅格结构在非准直入射情况下具有很好的声波发散效果。2.耦合共振系统双通滤波特性的研究声超构材料具有局域共振的特性,会导致材料出现动态的负有效质量或负的弹性模量,甚至是双负材料,这种具有负参量的声超构材料在超透镜、平板声聚焦上都有好的表现。局域共振型声超构材料的研究进展及发展过程可以参见论文第一章。论文第三章首先简要介绍了薄膜型声超构材料的研究现状。随后提出了我们所构建的双耦合共振系统,PE环——铝块共振系统和薄膜——空气柱系统。这样一个双耦合共振系统具有双通滤波的特性,局部的速度振动图像证实了低频透射峰是由于薄膜——空气柱系统的本征振动；两个系统的耦合作用影响着透射谷和高频透射峰。更重要的是,两个透射峰可以通过两个系统分别独立地控制。这样很容易实现一种声屏蔽和双通滤波的声学装置。3.基于非线性碰撞的分谐频装置论文第四章,主要介绍了非线性碰撞的分谐频效应的相关调研工作。首先简单介绍了超声远红外无损检测中出现的声混沌现象,随后介绍了非线性碰撞中的次谐波的研究模型及有限元分析模型,然后提出了我们所构建的非线性碰撞分谐频的模型,利用我们所构建的PE环——铝块共振系统代替变幅杆去撞击金属板,并且采用另一个不同共振频率的PE环——铝块系统代替金属板,这样声波从不同共振系统方向入射时会产生更加丰富的物理效果。最后利用ANSYS对模型进行了前期简单的分析处理。第五章,是关于本文的工作总结及对未来工作的展望。
[Abstract]:In this paper, the structure and performance of new acoustic devices are mainly studied. The whole paper is divided into five chapters, except the introduction and summary and prospect of chapters-and 5. The main research work is divided into three parts: (1) the study of the supernormal transmission of the acoustic grid structure with the substrate; (2) the study of the double pass filtering characteristics of the coupled resonance system; (3) the harmonic frequency divider based on nonlinear collision. The brief contents of each part are as follows: 1. Study on the supernormal transmission of the subwavelength slotted structure the phenomenon of supernormal transmission occurs when the light waves pass through the subwavelength slit as well as the acoustic waves. In the first chapter, the research progress of supernormal transmission of acoustic grid structure is briefly introduced. Compared with the excitation of plasma in grating lattice, the supernormal transmission of acoustic grid is due to the excitation of transversely coupled resonance mode sound waves in the grid. The superstructure of the grid structure has good applications in acoustic collimation, unidirectional transmission and so on. In the second chapter, the unidirectional flow characteristics of the sonic grid structure with a substrate are briefly introduced, and it is pointed out that the one-way transmission is due to the sound wave being redistributed as a periodic source to excite the bending mode of the substrate, which radiates the sound wave. Then the transmission effect of sound field in the band gap domain is enhanced by changing the filling liquid between the grid and the film. Then the transmission effect of non-collimating incidence of sound wave is studied. It is found that the negative transmission effect will occur when the acoustic wave is not collimated and the propagation diagram of the acoustic field with negative transmission at different incidence angles is given. Finally, it is pointed out that the acoustic grid structure with a substrate has a good acoustic divergence effect in the case of non-collimating incidence. Study on Dual-pass filtering characteristics of coupled Resonance system; Acoustic superstructure materials have local resonance characteristics, which can lead to dynamic negative effective mass or negative elastic modulus, even double negative materials. This kind of acoustic superstructure material with negative parameters has good performance in supersonic lens and plate acoustic focusing. The research progress and development of local resonance acoustic superstructure materials can be found in Chapter 1 of this paper. In the third chapter, the research status of thin film acoustic superstructure materials is briefly introduced. Then we propose the double coupling resonance system, the PE ring aluminum block resonance system and the thin film air column system. Such a double coupling resonance system has the characteristic of double pass filter. The local velocity vibration image proves that the low frequency transmission peak is due to the intrinsic vibration of thin film air column system. The coupling of the two systems affects the transmission valley and the high frequency transmission peak. More importantly, the two transmission peaks can be independently controlled by two systems. This is easy to achieve a sound shielding and double-pass filtering acoustic device. 3. The fourth chapter mainly introduces the research work on the harmonic effect of nonlinear collision. In this paper, the phenomenon of acoustic chaos in ultrasonic far infrared nondestructive testing (NDT) is introduced briefly, and then the research model and finite element analysis model of subharmonics in nonlinear collisions are introduced. Then we present a nonlinear collision harmonic frequency model, and we use the PE ring-aluminum block resonance system we constructed to impact the metal plate instead of the variable amplitude bar. The aluminum block system, another PE ring with different resonance frequencies, is used to replace the metal plate, so that the sound waves incident from different resonance system directions will produce more abundant physical effects. Finally, the model is analyzed and processed by ANSYS. The fifth chapter is about the work of this paper and the prospect of future work.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN65

【共引文献】