基于动力参数的铁路桥墩损伤识别方法研究

发布时间：2018-02-13 12:25

本文关键词： 动力测试桥墩损伤识别频响函数置信准则模型修正　出处：《北京交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：桥墩作为支撑上部结构的重要构件,其工作状态直接影响整个桥梁的安全。快速可靠的明确墩台基础技术状态,科学的指导墩台结构的状态评定以及加固维修,对桥梁的运营管理有极大意义。本文以现有的基于动力测试的结构损伤识别研究成果为基础,对基于动力参数的铁路桥墩损伤识别方法进了研究,主要工作和结论如下： (1)研究了基于模态参数和模型修正理论的桥墩损伤识别方法。在模态频率及模态置信准则(MAC)的基础上,引入以一阶振型相邻分量比值构造的目标函数。通过数值分析表明,该方法仅仅应用前两阶模态,便可以实现对桥墩墩身和基础状态的同时识别。然而,该方法对模态识别精度有较高要求,抗噪能力较差。 (2)研究了基于频响函数相似性和模型修正理论的桥墩损伤识别方法。首次提出了以结构相邻测点频响函数模式置信准则(SAC)构造目标函数,通过模型修正对桥墩损伤进行识别的方法。本文通过理论和数值分析,从频率段选择、测点布置、抗噪声能力几个方面对该方法进行了探讨。分析结果表明,该方法的损伤识别结果准确可靠,方法具有一定的工程应用性。 (3)通过1：3比例缩尺桥墩模型试验,进一步对基于频响函数相似性和模型修正理论的桥墩损伤识别方法进行了实验研究。在模型桥墩上设计了几种典型的损伤形式,并用所提的损伤识别方法进行了评估。识别结果与现场观测结果吻合,从而证明了本研究所提桥墩损伤识别方法的可靠性。
[Abstract]:As an important component of the supporting superstructure, the working state of piers directly affects the safety of the whole bridge. The technical status of pier and abutment foundation is determined quickly and reliably, and the state evaluation and reinforcement of pier and abutment structure are scientifically guided. Based on the existing research results of structural damage identification based on dynamic testing, this paper studies the damage identification method of railway piers based on dynamic parameters. The main work and conclusions are as follows:. In this paper, the damage identification method of pier based on modal parameters and model modification theory is studied. On the basis of modal frequency and modal confidence criterion (Marc), the objective function constructed by the ratio of adjacent components of first-order modes is introduced. The numerical analysis shows that, Using only the first two modes, the method can recognize the pier and foundation state simultaneously. However, the accuracy of modal identification is high and the anti-noise ability is poor. In this paper, the damage identification method of bridge pier based on similarity of frequency response function and model modification theory is studied, and the objective function is constructed by using the confidence criterion of frequency response function (SAC) of adjacent measuring points for the first time. The method of identifying pier damage by model modification is discussed in this paper from the aspects of frequency section selection, measuring point arrangement and anti-noise ability through theoretical and numerical analysis. The result of damage identification is accurate and reliable, and the method has certain engineering application. Based on the model test of 1: 3 scale piers, the damage identification method of bridge pier based on the similarity of frequency response function and model modification theory is further studied. Several typical damage forms are designed on the model pier. The damage identification method proposed in this paper is evaluated, and the result is in agreement with the field observation result, which proves the reliability of the damage identification method proposed in this paper.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U443.22;U446

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