摘要压力管道的分布极为广泛，管道的安全运行与生产生活关系极为密切，因此保证管道的安全运行意义十分重大。随着管道数量的增多和运行时间的增加，管道设计、安装及运行管理中的问题逐渐暴露出来，为了及时发现问题，控制事故的发生，减少事故带来的损失，管道的腐蚀检测和泄漏检测就显得非常重要。
管道的长距离快速超声导波检测研究近年来受到国内外无损检测学者的极大关注，是管道检测技术发展的新方向。针对研究导波理论的重要性，以及计算分析管结构中导波的传播及缺陷反射过程的复杂性，本文将导波理论与数值计算方法相结合，对管状结构(波导)中超声导波的传播及在缺陷处的反射过程的数值计算方法进行了研究。
本课题的顺利完成将对管状结构材料中超声导波一些传播特性的认识具有十分重要的意义，为板状和管状结构材料的超声导波检测提供一定的理论依据。对国内在管状波导中超声导波的数值模拟研究方面仍比较薄弱的现状进行了一定程度的弥补。4357
关键词：超声导波；时间反转 ；无损检测
Abstract
The pipe Was distributed extremely abroad．The safe operation of pxpe had a very close relationship with the life and production．It had a great important significance to ensuring the safe operation of pipe．The problems was gradually exposed in the operation of pipe，with the increase in the number of channels and the increase in running time In order to timely identified problems and controlled accidents and reduced the losses caused by accidents．the pipe corrosion detection and leak detection was extremely important.
Study on the ultrasonic guided wave long range fast pipe detecting technique was brought into focus of by the scholars both at home and aboard in recent years，and the technique is a new orientation．for the significance of studying the guided wave theories and complexity of calculating and analyzing the courses of propagation and reflection from notches of guided waves in complex structures，the numerical method of calculating the propagation and reflection from notches of ultrasonic guided waves in cylindrical structures was studied through associating the guided wave theory with numerical simulation method.
Results in this paper can be used to improve inspection sensitivity and penetration power for a variety of practical NDE applications．The field of applying the numerical method to analyze the guided wave theory was a weakness in domestic studies，and the study was a supplement to the present situation
Keywords: ultrasonic；detect；notch
目 录
第1章  绪论    1
1.1  本论文的背景和意义    1
1.2 国内外的研究历史及现状    2
1.3 本论文的研究方案    4
1.4  本论文的主要内容、研究目标、主要特色    4
第2章 管道中超声导波的基本原理    5
2.1导波的概念与分类    5
2.2 导波的激发原理    5
2.3管道缺陷检测原理    5
2.4 管型结构中导波的模态分析    6
2．4.1 多模态现象与模态选择的重要性    6
第 3 章  超声导波在管道中的传播特性    9
3.1 管型结构中导波的频散与衰减    9
3．1.1 导波的频散现象    9
3．1.2 导波的衰减    9
3．1.3导波在管道中的频散方程    9
3．1.4 管结构中导波的频散曲线    13
3．1.5 频散现象的抑制方法    13
第4章 时间反转技术    14
4.1 传统方式对管道进行损伤检测    14 管型结构的宽频导波检测方法+建模程序:http://www.youerw.com/zidonghua/lunwen_996.html