【作者】 吕淼；

【导师】 赵歆冬；

【作者基本信息】 西安建筑科技大学 ， 防灾减灾工程及防护工程， 2010， 硕士

【摘要】 土木工程结构由于各种自然的和人为的作用,会出现损伤,当损伤积累到一定程度时,将会导致结构性能的下降甚至毁坏,对国家和人民的生命、财产造成严重的威胁,其经济损失不可估量。因此,对现有结构进行损伤的判别与定位有着极为重要的意义。近年来,随着社会的发展、科学技术的进步以及人们日益增长的物质文化需求,空间结构的应用越来越广泛。空间结构大多是一个城市乃至国家的公共性建筑和标志性建筑,一旦发生破坏,影响巨大。因此及早发现结构的损伤,并采取防范措施尤为重要。而目前,对于梁、板类结构的损伤识别研究较多,并取得了一定的研究成果,但由于空间结构比较复杂,自由度较多,将这些成果应用于空间结构的损伤检测时效果较差。为了寻找适用于空间结构的损伤识别方法,本文以一三层空间刚架为研究对象,对空间结构的损伤识别方法进行了较深入的研究。本文首先阐述了结构损伤识别的研究目的和意义,结构健康监测和结构损伤识别及其国内外研究现状；其次,在对结构损伤识别的分类、结构损伤识别的方法以及基于动力特性的损伤发现与定位理论进行深入研究的基础上,选择采用单元模态应变能法和基于一阶振型的两阶段损伤识别方法来对模型结构进行损伤识别与定位。第三,应用大型有限元分析软件ANSYS10.0建立了一三层空间刚架模型,并选择应用Subspace法对该模型进行模态分析。用刚度折减法来模拟杆件的损伤,通过模态分析获得完好结构和损伤结构的前十阶固有频率和振型。最后,对于获得的完好结构和损伤结构的模态参数分别应用基于单元模态应变能和基于一阶振型的结构两阶段的损伤识别方法对模型进行损伤的定位。结果证明这两种方法在进行空间结构的单损伤识别时都是有效的,都能够精确的定位杆件的损伤。论文的主要研究工作及结论对空间钢结构的损伤识别与定位有一定的参考意义。更多还原

【Abstract】 Engineering structure will be damaged during their service period with the affects of various natural and man-made factors. With the damage accumulation, the structure’s performance will be degraded or even probably the structure will be destroyed. That’s harmful for people’s lives and property. Therefore, it is an important issue to detect and locate the damage occurred in structures in much early time.Now, more and more the spatial structures are emerged, even some of them become the landmark of a city or a country. Once these structures are failed, the effects will be vastness. So it is necessary to find and locate the damage as early as possible. In the field of structural damage identification, however, the researches are focused on the beams and the planes, the results could not be used for damage estimation of spatial structures because of their complex performances. In order to find suitable methods for spatial structural damage identification, an intact three-storey space frame and a damaged three-storey space frame are analyzed use the finite element analysis software ANSYS10.0.In this paper, firstly, the recent researches on the structural damage identification are introduced. Secondly, after analyzing the classification and the detection methods of the structural damage, two of the methods (method of analysis element modal strain energy and the two-stage damage identification method based on first mode shape) are selected to detect and locate the damage in structures. Thirdly, by the use of the finite element analysis software ANSYS10.0, a three-storey spatial steel framework analysis model is established, and the modal analysis is carried out by the Subspace method. The damage of the structure is simulated by stiffness reduction method in the model establishing. The first ten frequencies and mode shapes are extracted. Finally, modal parameters of the intact and damaged structure calculated are applied on two methods (element modal strain energy analysis method and the two-stage damage identification method based on first mode shape) to detect and locate the structural damage. The calculating results indicate that two methods are valid in identifying the damage in spatial structure, and accurate in damage location. The conclusions are useful for damage identification and location in spatial framework structures.更多还原