电磁声探头辐射声场研究
文献类型：学位论文
| 作者 | 陈秋颖 |
| 学位类别 | 博士 |
| 答辩日期 | 2009-05-21 |
| 授予单位 | 中国科学院声学研究所 |
| 授予地点 | 声学研究所 |
| 关键词 | 电磁声探头 辐射声场 有限元法 ANSYS软件 |
| 其他题名 | Study on the Radiated Sound Field of Electromagnetic Acoustic Probe |
| 学位专业 | 声学 |
| 中文摘要 | 电磁声检测技术具有非接触、无需耦合剂和超声回波信号稳定等优点，因而受到超声无损检测领域众多研究者的关注。电磁声探头是电磁声检测技术的关键器件，分析和了解它的辐射声场特性既是一个基本声学问题，又对电磁声探头的设计和电磁声检测技术的应用具有重要意义。 本论文在国家自然科学基金项目资助下，对我们课题组研制的一套电磁声实验系统所使用的电磁声探头的辐射声场特性进行了理论和实验研究。论文主要研究内容如下所述： 论文的第一章，简述了电磁声探头激发和接收超声波的基本原理及其特点，综述了前人在电磁声探头辐射声场研究方面的主要工作进展，指出了目前的研究现状和存在的问题，概括了本论文的主要研究工作和创新性。 论文的第二章，应用有限元数值计算方法对电磁声探头在导电固体表面附近产生的涡流和洛仑兹力分布以及辐射声场的位移分布进行了仿真分析。介绍了有限元方法和ANSYS软件的一些相关知识，给出了用ANSYS软件仿真计算得到的几种不同模型的二维和三维物理参数分布，对有缺陷试块的模型也进行了仿真计算，为进一步分析电磁声探头辐射声场的指向性奠定了基础。 论文的第三章，分析了一种圆环形螺线圈与垂直偏置磁场配置的电磁声探头在非铁磁性介质中的辐射声场特性。根据电磁感应原理建立了探头的数学物理模型，从理论上推导出了声场位移的解析解。数值计算了横波和纵波的切向和法向指向性，实验测试了课题组研制的电磁声实验系统所使用的探头的辐射声场，理论计算结果与实验测试结果符合较好。 论文的第四章，对本文所做的电磁声探头辐射声场研究工作进行了总结，提出了今后的可研究内容和方向。 |
| 英文摘要 | Electromagnetic acoustic testing technology has aroused extensive concern in the field of ultrasonic nondestructive testing due to its advantages of non-contact with the test specimen, no fluid couplant and good signal reproducibility. Electromagnetic acoustic probe is the key device of electromagnetic acoustic testing technology. Therefore, analyzing and understanding the characteristics of the radiated sound field by electromagnetic acoustic probe are not only a basic acoustical problem, but also of great significance for the design of electromagnetic acoustic transducer (EMAT) and the applications of electromagnetic acoustic testing techniques. The project of this thesis is supported by the National Science Foundation of China. Theoretical analysis and experimental study on the radiated sound field of the electromagnetic acoustic probe used by the electromagnetic acoustic experimental system that is developed by our research team are carried out. The main research contents in this paper are as follows: Chapter one, which is the part of Introduction, the basic principles and characteristic of transmitting and receiving ultrasonic waves by electromagnetic acoustic probe are explained, the previous research development on radiated sound field of electromagnetic acoustic probe are reviewed, the present situation and difficulties are pointed out, and the main research and innovation in this thesis are presented. Chapter two, numerical simulation analysis of electromagnetic acoustic probe is carried out and the distribution of eddy current, Lorentz force and the displacement of the radiation field are obtained. It introduces some relevant knowledge of the Finite Element Method and ANSYS software, presents the distribution of physical parameters from several different models including 2D and 3D calculated in ANSYS, and also computes the model of specimen with flaw. These lay the foundation for further study on the radiation directivity of electromagnetic acoustic probe. Chapter three, the radiated sound field excitated within a non-ferromagnetic aluminum by an electromagnetic acoustic probe consisting of circle-spiral coil and vertical bias magnetic field is studied. The physical and mathematical model is established according to the principle of electromagnetic induction, and the analytical solutions of displacement field are deduced theoretically. The tangential and normal directivity pattern of shear wave and longitudinal wave are calculated numerically and the sound field of the electromagnetic acoustic probe is measured through our electromagnetic acoustic experimental system. Theoretical prediction results are conformed well to the experimental ones. Chapter four, the work on the radiated sound field in this thesis and the future research are summarized. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 83 |
| 源URL | [http://159.226.59.140/handle/311008/530]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 陈秋颖. 电磁声探头辐射声场研究[D]. 声学研究所. 中国科学院声学研究所. 2009. |
入库方式： OAI收割
来源：声学研究所
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