桥梁结构自振特性测试分析方法研究

发布时间：2018-03-17 20:04

本文选题：自振特性　切入点：动力性能　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：桥梁结构的自振特性参数是反映结构整体工作性能的综合性指标，是桥梁结构动力分析的基础，是评价桥梁动力性能的重要依据。因此，自振特性测试分析在评价结构性能体系中具有重要地位。然而，鉴于桥梁结构的振动形态的复杂性和随机性，目前对自振特性参数的评定方法研究尚处不断探索之中，并未形成完善的体系与统一的标准；在另一方面，自振参数测试结果受试验方法、分析参数、数据处理方法等诸多因素的影响，工程实践中自振参数识别精度低，甚至误判的现象也不少见。因此，对自振特性参数的测试、分析方法以及其对结构评价方法的研究是很有必要的，本文通过理论分析，并结合现场试验，针对现有测试分析方法存在的局限性和不足，通过样本统计分析、试验验证等方法，就如何提高桥梁自振特性测试方法、数据处理方法的可靠性以及如何有效地利用测得的数据来判断结果的正确性等方面展开了系统的研究和分析。本文首先指出了目前自振特性测试中存在的测点布置盲目性、试验方法缺乏针对性、参数设置不合理，，针对这些问题作者给出自己的建议。并对自振特性测试方法的优化进行探讨，同时以实桥为对象，分析了测试时采样频率设置不当使采集的信号失真，并对各采样参数的设置提出了合理化建议。其次，对自振参数测试数据处理的方法进行探讨，对于时域法本文进行量化分析了采样频率的大小对实测频率计算结果的影响，并探讨了多周期平均对计算精度的改善；对于频域法本文根据项目组提出的能量平均法对阻尼比的识别，进一步提出了不同时差对计算结果的影响；同时在利用半功率点法识别阻尼比时，为提高频率分辨率，统计了不同谱线数对分析结果的影响。最后，本文定量分析了测试时结构实际的刚度、频率与理论计算的刚度、频率之间的相互关系，提出了根据现场测得的结构频率，求得结构实际刚度以及刚度的变化，对结构性能进行评价；分析了依据实测阻尼比对结构性能进行评价存在一定的可靠性，并统计分析了阻尼比与冲击系数的相关性。
[Abstract]:Vibration characteristics of bridge structure is a comprehensive index reflecting the structure overall performance, is the foundation of bridge structure dynamic analysis, is an important basis for evaluating the dynamic performance of the bridge. Therefore, the self vibration characteristics analysis plays an important role in the structural performance evaluation system. However, in view of the complexity of the bridge structure and the vibration shape random, current research evaluation method of vibration characteristics is still being explored, did not form a unified and perfect system and standard; on the other hand, the vibration parameters of test results by test method, parameter analysis, effects of many factors such as the data processing method in engineering practice, self recognition precision and low vibration parameters and even misjudgment of the phenomenon is not uncommon. Therefore, the vibration characteristics test, analysis method and the structure of the evaluation method is very necessary, this paper through theoretical analysis Analysis, combined with field test, the limitations of the existing analysis methods of test and shortcomings, through statistical analysis of samples, test methods, how to improve the bridge self vibration characteristic test method, the reliability of the method of data processing and how to effectively use the measured data to judge the validity of such aspects of the research and analysis of the system.
This paper points out the current existing self vibration test in the test point arrangement test method for blindness, lack of pertinence, the parameter setting is not reasonable, aiming at these problems, the author gives his own advice. And optimization of the self vibration characteristic test method were discussed, at the same time to bridge as the object, analyzed the test set sampling frequency improper acquisition signal distortion, and puts forward reasonable suggestions for the parameters of each sampling set.
Secondly, to discuss the vibration parameter test data processing method, this paper makes a quantitative analysis of time domain method for the effect of sampling frequency on the size of the measured frequency calculation results, and discusses the multiple period average on the calculation accuracy is improved; for the frequency domain method according to the project team's average energy method to identify the damping ratio. Put forward different time effect on the results; at the same time using the half power point method to identify damping ratio, in order to improve the frequency resolution, the statistics of different lines of influence on the analysis results.
At last, this paper quantitatively analyzes the test of actual structure stiffness, frequency and stiffness calculation theory, the relationship between frequency, frequency is proposed according to the structure of the site measured, calculated structure stiffness and the actual stiffness changes, to evaluate the structure performance; analyzed based on the measured damping ratio on the performance of there is a certain reliability evaluation, and statistical analysis of the correlation between damping ratio and impact factor.

【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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