毕业论文移动版

摘要随着激光超声技术的发展，其检测手段也日益丰富， 应用范围更加广泛。激光超声检测技术是一种利用激光脉冲激发超声从而实现检测的方法。作为激光检测技术的一个分支，近几年在材料性能测量、光谱分析等方面得以广泛应用，激光超声检测的最主要的优点是非接触检测，可用于各种较复杂外形的特性检测，因此激光超声检测技术是一种极有应用前景的新的无损检测技术。

激光超声检测技术是利用激光脉冲照射样品表面，激发出超声波，并利用光学方法对超声波进行检测，从而实现对样品进行无损检测的一种方法。粘结结构以其优越的性能而广泛应用于化工、航空航天及食品等各领域，但在其制造和使用过程中常常会出现界面缺陷，如粘结不良、气孔等现象，这些缺陷的存在将会影响材料使用的可靠性，在使用过程中由于界面缺陷的存在而造成的灾难性事故时有发生。为了保证产品质量和使用安全，对粘结结构界面质量的检测是十分有意义的。64388

本文基于激光超声的热弹激发机理，建立了激光在粘接系统中激发超声波的理论模型，采用有限元法对激光在玻璃-钢粘接系统中激发的弹性声波进行了数值模拟，并根据计算得到的不同粘接情况下的波形，分析了激光超声在粘接系统中的传播。通过数值模拟结果的分析，得到如下结论：利用激光超声技术对界面波进行了测量，实测的几种材料组合的Stoneley波与理论符合很好。实验结果表明，全光学激光超声技术是激发与检测界面波的有效手段之一。

毕业论文关键词  激光超声 无损检测 粘接缺陷 有限元方法

毕业设计说明书（论文）中文摘要

 毕业设计说明书（论文）外文摘要

Title   the research of Laser ultrasonic nondestructive testing Bonding defects                 

Abstract With the development of laser ultrasonic technique and its testing methods are also increasingly abundant, wider range of applications. Laser ultrasonic detection technology is a method of detection of pulsed laser induced ultrasound in order to achieve. As a branch of laser measuring technology, in recent years in areas such as performance measurement, spectroscopic analysis to a wide range of materials, laser-ultrasonic detection of the most important advantages is the non-contact measurement, can be used for a variety of more complicated characteristics detection, laser ultrasonic detection technology is a tremendous prospect in nondestructive testing of new technologies. 

Laser ultrasonic detection technology is the use of laser pulse irradiation surface inspired ultrasound, and the use of optical methods for ultrasonic testing to achieve a method for non-destructive testing of the samples. Bonded structures are widely used for their superior performance in areas such as chemical, aerospace and food, but in the course of its manufacture and use of interface defects often occur, such as bonding phenomena such as bad,tomatal . these flaws will affect the reliability of the material used, in the course of using the result of the existence of interface defects catastrophic accidents occur from time to time. In order to ensure the quality and safety of products, on the quality detection of interface bonding structure is very meaningful. 

This article is based on mechanism of Thermo-elastic stimulation of laser ultrasonic, established the theory of laser-excited ultrasonic bonding system model using finite element method for laser in glass-steel bonding system in numerical simulation of elastic sound waves excited by, and depending on the calculated bond case waveform, analysis of propagation of laser-generated ultrasonic bonding system. Through the analysis of numerical simulation results, and came to the following conclusion: measurement of Interfacial waves by using laser ultrasonic technique, measurement of several materials combinations of Stoneley wave in accordance with theory very well. Experimental results show that all-optical laser ultrasonic technique is one of the effective means of stimulation and detection of Interfacial waves. (责任编辑：qin)