压电横波直探头和电磁超声横波探头空间响应特性的研究
文献类型：学位论文
| 作者 | 吴迪 |
| 学位类别 | 博士 |
| 答辩日期 | 2007-05-18 |
| 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 | 无损检测 横波 换能器 声场 数值计算 电磁超声 |
| 其他题名 | Studies on the spatial responses of shear wave by a normal piezoelectric probe and two EMATs |
| 学位专业 | 声学 |
| 中文摘要 | 超声无损检测技术受到工业界的普遍重视，得到广泛的应用，其中换能器技术是超声检测中的核心技术。论文以两类垂直辐射的横波换能器为对象，分五个部分研究了其辐射空间响应特性和声场数值计算方法。 第一章为绪论，简单总结了压电和电磁超声换能器有关辐射空间响应研究的概况及本论文的主要研究内容。 第二章研究了采用2/2型压电复合材料制作的一种水平偏振横波直探头的稳态空间响应特性，给出了相应声场分布和指向性图。 第三章研究了该横波直探头的瞬态空间响应特性，给出了两种表面力源辐射声场的严格解析解，给出了中轴面上水平位移的瞬态特性，从辐射的不同时刻声场图中清晰可见直达波、边缘波和头波。 第四章研究了跑道线圈电磁超声探头由洛伦兹力换能机制产生的辐射声场，将辐射力源简化为非均匀的水平剪切力源，理论分析了该电磁超声在半无限大介质铝中辐射的横波声场。 第五章对铝和钢半圆试块上辐射的横波声场分别进行了试验研究。表明在同样条件下钢中辐射声场与铝中辐射声场有显著不同。 第六章研究了圆形螺旋线圈电磁超声探头由洛伦兹力换能机制产生的辐射声场，给出了涡流、等效表面力源和辐射声场的计算方法，分析了此螺旋线圈换能器在铝试块上的辐射指向性。 |
| 英文摘要 | Material testing and evaluation plays an important role in quality control of commercial products and improvement of their manufacturing processes for the purpose of guaranteeing the reliability of fabricated products and structural components and increasing their production efficiency. Development of physics, electronics, material science and numerous material testing techniques, has paved a wide floor of promising applications for various new non-destructive testing techniques among which ultrasonic technique is the versatile one in industrial circle. This thesis studies the ultrasonic wave fields radiated by two normal shear wave transducers of different type, focusing at force-source model, theoretical analysis, numerical simulation and experimental verification. The first chapter is an introduction where framework of the research results obtained in the thesis is briefly outlined after summarizing survey of the research and development pertinent to the spatial responses of wave fields radiated by piezoelectric and the electromagnetic ultrasonic transducers. The second chapter studies the field of horizontally polarized ultrasonic shear wave radiated by a 2/2 piezoelectric composite normal probe. The analytic field solutions for two different surface forces were deduced and the field distribution and directivity patterns were given by numerical calculations. The third chapter analyzes the ultrasonic transient field of the normal shear wave probe based on the second chapter. The analytic field solutions for two different surface force sources were deduced and the transient displacement field distribution on the central cross-section was plotted by numerical calculations. The fourth chapter studies the horizontally polarized ultrasonic shear wave field emitted by an Electromagnetic Acoustic Transducer (EMAT) with the surface force distribution approximately described as an inhomogeneous horizontal shear force. The shear wave directivity pattern was plotted by numerical calculations based on our analytic solutions of the wave field in previous chapter. The fifth chapter experimentally studies the radiated shear wave fields in the semicircle aluminum and steel blocks in the experimental system of EMAT generation and piezoelectric transducer reception. The results showed that the two shear wave fields in the aluminum and steel blocks were obviously different under the similar conditions for which a possible qualitative background was described. The sixth chapter studies the radiated acoustic field produced by a spiral coil EMAT probe with Lorentz force mechanism. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 103 |
| 源URL | [http://159.226.59.140/handle/311008/158]  |
| 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 | 吴迪. 压电横波直探头和电磁超声横波探头空间响应特性的研究[D]. 声学研究所. 中国科学院声学研究所. 2007. |
入库方式： OAI收割
来源：声学研究所
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