数字散斑相关测试技术在桥梁健康监测中的问题研究

【作者】 吴加权；

【导师】 马琨；

【作者基本信息】 昆明理工大学 ， 物理电子学， 2006， 硕士

【摘要】 近年来,随着国民经济的飞速发展,我国公路桥梁建设取得了令人瞩目的巨大成就,很多省市已初步形成以高等级公路为主干架的四通八达的公路网。桥梁是公路的重要组成部分,我国每年都有大量新建成的公路桥梁需要通过质量安全检测验收。同时,对于建成通车以后的在役桥梁,随着时间的推移,由于种种因素会使桥梁安全度有所下降,如原设计未达到使用要求、施工未达到设计要求、桥梁存在病害,材料老化、锈蚀而未及时养护、车辆荷载增大或交通量剧增,桥梁伸缩缝损坏或桥面不平整对桥梁结构带来的不利影响等等。很多桥梁已存在着巨大的安全隐患,几乎每年都有因桥梁倒塌事故造成重大经济损失的安全事故报道。因此,如何采用一种经济、高效、快速的检测方法对桥梁结构的使用健康状况进行监测和评估是值得关注和研究的一个重要问题。 数字散斑相关测试技术是随着光电子信息处理技术以及数字图像处理技术迅速发展起来的一种高精度的二维面内位移与应变的无损检测方法,在理论研究与实际工程中都有着广泛的应用前景,本文就数字散斑相关测试技术实际应用于大型、特大型桥梁工程的健康安全监测评估中所遇到的诸多问题进行基础性研究,为该项技术用于桥梁的健康安全监测及评估打下实验基础。文章主要通过以下几部分完成。第一部分对数字散斑相关理论进行了全面系统的阐述,并通过双线性插值将实验测量精度由整像素提高到亚像素,进一步为钢筋混凝土梁的微应变测量从理论和软件技术方面提供保障。第二部分通过Visual C++编程语言编写了RGB彩色图像校正软件,利用软件对一次现场桥梁载荷应力应变测量实验加载过程中不同时段、不同天气状况下所采集的散斑图进行图像更多还原

【Abstract】 Along with national economy fast developing, the highway bridge construction of our country has gotten the huge achievement in recent years. Highway nets extending in all directions of many province cities that take Higher- level highway as main skeleton have already formed preliminarily. Bridge is the important composition part of highway, many new established highway bridges are needed to pass through quality safely detection acceptance in every year. At the same time, the bridge that established and open to traffic, various factors can make bridge safe degree drop along with time passed. Many bridges have had huge safe hidden trouble and nearly have bridge collapse accident reported every year that causes significant economic loss. Therefore, how to adopt a kind of economic, efficient, fast detection methods to the structure of bridge healthy condition monitor and evaluate is an important problem of worth-whiles solicitude and research.Digital speckle correlation method is a nondestructive detection method that development gets up along with photoelectron information technology and digital image technology. It has been extensively used to accurately determine two-dimensional in-plane displacements and strains in both theoretic study and engineering measure. Many possible problems are reached in this paper when the digital speckle correlationmethod is used in the large construct safe detection.This paper is completed mainly with chapter four. The theory of digital speckle correlation is discussed and bilinear is used to raise the measure precision from pixel to inferior pixel in part one. In chapter two, one bridge experiment of displacements and strains in different time and different weather condition speckle image are rectified through the image rectify software programming of Visual C++. It discussed the feasibility of digital camera using in digital speckle correlation method. The different distances and different displacements condition through selecting the different sizes of particle experiments are researched and compared in chapter three. The speckle influence of particle size for measure precision is given. According to relative errors of experiments result, under given image collection system, in different image collection distance how to select reasonably size of particle to obtain measure purpose are given. A reliable experiment selection for the future application of DSCM measurement using in the large construct safe detection of speckle field making is provided. In chapter four, the content of thesis studied is used to get the elastic modulus of PMMA through the loading measurement of 3 point bending. The change of every mechanics performance is given by bridge structure loading experiment. It is not only verified the experiment regular that we get, but also offered a kind of new experiment method to explore through experiment to get stress-strain relation. Finally, the main achievements of this thesisare summed up and direction of further developing in this field ispointed out.It proves that the contents and the method of studying in this paper solved the problems in bridge structural healthy safe detection. It established theoretical basic and experiment foundation for bridge structure health monitoring.更多还原