基于挠度影响线的拱结构损伤识别研究

发布时间：2018-08-06 12:53

【摘要】：桥梁结构的健康状态对于交通运输乃至国民经济发展都有着重要影响,如何实现对桥梁结构损伤部位的定位和损伤程度的判断,以便及时加以修护是当前桥梁健康诊断领域的研究热点。本文针对拱桥结构的拱肋损伤问题进行研究,提出基于挠度影响线原理的损伤识别方法,并对其有效性进行了试验验证,完成的主要研究工作如下:1.对目前国内外常用的几种损伤识别方法包括:模态振型法、柔度矩阵法和固有频率法进行了对比研究。首先介绍各类方法的理论基础,然后采用有限元软件Midas/Civil建立了单拱结构带损伤的有限元模型,对以上几种既有方法的有效性进行了数值算例验证,并对比分析了几种方法的优缺点。2.介绍了拱结构的变形几何关系和振动理论,研究了挠度影响线法的基本原理,在总结前人研究的基础上,提出了基于拱肋挠度影响线及其一、二阶导数差值的拱结构损伤识别方法,通过数值算例表明,该方法对拱结构损伤敏感,能有效定位损伤和评估损伤程度。此外,本文还利用有限元方法模拟分析了不同加载速度对于损伤识别效果的影响。3.研究了基于挠度影响线损伤识别方法中位移传感器的优化布置方法,利用有效独立法和改进的有效独立法进行不同工况拱结构的测点优化计算,并用Midas数值算例进行了验算。通过与简支梁进行对比发现,与简支梁不同,拱结构1/4跨附近挠度影响线幅值较大,易于测量,能更为有效地识别损伤。4.进行了大量单拱模型的损伤识别试验。在实验室条件下,采用挠度影响线法对不同工况的拱结构进行了损伤识别,并对比分析了不同挠度测点对损伤识别的影响。试验结果表明,挠度影响线二阶导数差能有效定位损伤并判断损伤程度。不同测点的挠度影响线幅值差异较大,选取合理测点的挠度影响线进行损伤识别为拱结构损伤检测提供了一种新的方法。
[Abstract]:The health status of bridge structure has an important impact on transportation and even the development of national economy. How to realize the location of bridge structure damage and how to judge the damage degree. In order to repair in time is the current research hotspot in the field of bridge health diagnosis. In this paper, the arch rib damage problem of arch bridge structure is studied, and a damage identification method based on deflection influence line principle is proposed, and its effectiveness is verified by experiments. The main research work is as follows: 1. Several damage identification methods used at home and abroad, including modal mode method, flexibility matrix method and natural frequency method, are compared and studied. Firstly, the theoretical basis of various methods is introduced, then the finite element model of single arch structure with damage is established by using the finite element software Midas/Civil, and the effectiveness of these existing methods is verified by numerical examples. The advantages and disadvantages of several methods are compared and analyzed. The deformation geometry relation and vibration theory of arch structure are introduced. The basic principle of deflection influence line method is studied. The second derivative difference method is used to identify the damage of arch structure. Numerical examples show that the method is sensitive to the damage of arch structure and can effectively locate the damage and evaluate the damage degree. In addition, the finite element method is used to simulate and analyze the effect of different loading speed on damage identification. The optimal arrangement method of displacement sensor based on deflection effect line damage identification method is studied. The effective independent method and the improved effective independent method are used to calculate the optimum measuring points of arch structures under different working conditions. An Midas numerical example is used to verify the results. By comparing with simply supported beam, it is found that, unlike simply supported beam, the deflection near 1 / 4 span of arch structure has a great effect on the amplitude of the line, which is easy to measure and can be used to identify damage more effectively. A large number of single arch model damage identification tests were carried out. Under laboratory conditions, the damage identification of arch structures under different working conditions was carried out by using deflection influence line method, and the effects of different deflection measuring points on damage identification were compared and analyzed. The experimental results show that the second derivative difference of deflection can effectively locate the damage and judge the damage degree. The deflection influence line amplitude of different measuring points is quite different. Selecting the deflection influence line of reasonable measuring points to identify the damage of arch structure provides a new method for the damage detection of arch structure.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446

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