基于结构动力特性的梁桥损伤识别技术研究
发布时间：2018-10-17 18:53
【摘要】：自20世纪70年代以来，国内桥梁建设工程取得了丰富的成果，很多复杂化、大型化的桥梁相继问世。桥梁结构，作为一个地区交通网络咽喉的重要建筑物，保障其结构的安全性和耐久性尤为重要。我国桥梁数量庞大，许多既有桥梁由于设计、施工、超载、自然腐蚀等原因，出现了不同程度的老化、破损、裂缝等现象。为保证这些桥梁有足够的安全性继续使用，需要监测和评估桥梁结构的损伤状态，，从而对桥梁结构进行相应的维修和加固，这个过程就是桥梁健康监测和结构损伤识别。 桥梁健康监测系统的核心内容就是结构损伤识别。结构损伤的出现，表现为实际结构动力特性（固有频率、振型模态参数等）发生改变。因此可以通过对结构动力特性参数的分析，判断结构损伤出现的位置和程度。本文重点研究梁式结构由于损伤引起的固有频率变化，并采用指纹分析的方法，研究结构的损伤定位问题。 论文首先对结构损伤识别进行概述，比较详细地介绍了结构损伤识别的基本方法，着重对比分析了分别基于静力测试和动力测试的损伤识别方法。 其次，介绍梁桥结构动力损伤识别方法，根据理论建立三种损伤识别频率指纹，分别是频率变化比、频率变化平方比和正则化的频率变化率。比较这三种指纹进行损伤识别的精准度，发现正则化的频率变化率指纹单调性最好，结构损伤定位的效果也比较好。再单独讨论正则化频率指纹的稳定性，分析梁的损伤单元宽度对频率指纹的影响，并以梁式结构为例，指出频率指纹进行损伤定位的原则和步骤，并进行有限元模型验证，表明正则化的频率变化率指纹进行损伤定位的精度还是比较高的，值得一提的是，频率指纹对结构对称损伤的定位尚需附加其它识别条件。 然后，对基于动力特性的损伤识别方法中出现的误差进行理论分析，探讨了动力测试误差、模型误差以及算法中存在的数值计算误差。并针对误差来源分析介绍了三种误差影响的减少方法。 最后，介绍了桥梁健康监测系统，论述健康监测系统的构成以及与结构损伤识别的关系，重点说明传感器优化布置在健康监测系统中的意见以及发展前景。
[Abstract]:Since the 1970s, the domestic bridge construction project has made rich achievements, a lot of complex, large-scale bridges have come out one after another. Bridge structure, as an important building in regional traffic network, ensures the safety and durability of its structure. The number of bridges in China is huge, many of the existing bridges appear different degrees of aging, breakage and cracks due to the design, construction, overload, natural corrosion and other reasons. In order to ensure the safety of these bridges, it is necessary to monitor and evaluate the damage state of the bridge structure, so as to repair and strengthen the bridge structure. This process is the bridge health monitoring and structural damage identification. Structural damage identification is the core of bridge health monitoring system. The occurrence of structural damage is manifested by the change of the actual structural dynamic characteristics (natural frequency, modal parameters, etc.). Therefore, the location and extent of structural damage can be judged by analyzing the dynamic characteristic parameters of the structure. In this paper, the natural frequency change of beam structure caused by damage is studied, and the damage location of beam structure is studied by fingerprint analysis. Firstly, the paper summarizes the structural damage identification, introduces the basic methods of structural damage identification in detail, and analyzes the damage identification methods based on static test and dynamic test respectively. Secondly, the dynamic damage identification method of beam bridge structure is introduced. According to the theory, three kinds of damage identification frequency fingerprints are established, which are frequency change ratio, frequency change square ratio and regularization frequency change rate. Comparing the accuracy of damage identification with these three kinds of fingerprints, it is found that the frequency change rate of regularization is the best, and the effect of structural damage location is better. Then the stability of regularized frequency fingerprint is discussed separately, and the influence of damage element width of beam on frequency fingerprint is analyzed. Taking beam structure as an example, the principle and procedure of damage location by frequency fingerprint are pointed out, and the finite element model is verified. The results show that the accuracy of damage location by regularized frequency change rate fingerprint is still relatively high. It is worth mentioning that the frequency fingerprint has to attach other identification conditions to the location of structural symmetrical damage. Then, the errors in the damage identification method based on dynamic characteristics are analyzed theoretically, and the dynamic test error, model error and numerical calculation error in the algorithm are discussed. According to the error source analysis, three methods of reducing error influence are introduced. Finally, this paper introduces the bridge health monitoring system, discusses the constitution of the health monitoring system and the relationship between the health monitoring system and the structural damage identification, and emphasizes the views and development prospects of the optimal layout of the sensors in the health monitoring system.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3;U446
本文编号：2277634
[Abstract]:Since the 1970s, the domestic bridge construction project has made rich achievements, a lot of complex, large-scale bridges have come out one after another. Bridge structure, as an important building in regional traffic network, ensures the safety and durability of its structure. The number of bridges in China is huge, many of the existing bridges appear different degrees of aging, breakage and cracks due to the design, construction, overload, natural corrosion and other reasons. In order to ensure the safety of these bridges, it is necessary to monitor and evaluate the damage state of the bridge structure, so as to repair and strengthen the bridge structure. This process is the bridge health monitoring and structural damage identification. Structural damage identification is the core of bridge health monitoring system. The occurrence of structural damage is manifested by the change of the actual structural dynamic characteristics (natural frequency, modal parameters, etc.). Therefore, the location and extent of structural damage can be judged by analyzing the dynamic characteristic parameters of the structure. In this paper, the natural frequency change of beam structure caused by damage is studied, and the damage location of beam structure is studied by fingerprint analysis. Firstly, the paper summarizes the structural damage identification, introduces the basic methods of structural damage identification in detail, and analyzes the damage identification methods based on static test and dynamic test respectively. Secondly, the dynamic damage identification method of beam bridge structure is introduced. According to the theory, three kinds of damage identification frequency fingerprints are established, which are frequency change ratio, frequency change square ratio and regularization frequency change rate. Comparing the accuracy of damage identification with these three kinds of fingerprints, it is found that the frequency change rate of regularization is the best, and the effect of structural damage location is better. Then the stability of regularized frequency fingerprint is discussed separately, and the influence of damage element width of beam on frequency fingerprint is analyzed. Taking beam structure as an example, the principle and procedure of damage location by frequency fingerprint are pointed out, and the finite element model is verified. The results show that the accuracy of damage location by regularized frequency change rate fingerprint is still relatively high. It is worth mentioning that the frequency fingerprint has to attach other identification conditions to the location of structural symmetrical damage. Then, the errors in the damage identification method based on dynamic characteristics are analyzed theoretically, and the dynamic test error, model error and numerical calculation error in the algorithm are discussed. According to the error source analysis, three methods of reducing error influence are introduced. Finally, this paper introduces the bridge health monitoring system, discusses the constitution of the health monitoring system and the relationship between the health monitoring system and the structural damage identification, and emphasizes the views and development prospects of the optimal layout of the sensors in the health monitoring system.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3;U446
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