基于实测的大跨度斜拉桥结构健康监测基准有限元模型研究
发布时间：2019-01-08 19:50
【摘要】：随着桥梁工程设计和施工技术的不断发展,大跨度斜拉桥不断涌现,斜拉桥结构的刚度变得越来越柔,对风和地震为主的动力荷载作用十分敏感。因此对斜拉桥的结构健康监测及损伤识别等的要求不断提高,必须建立一个能全面准确地反映大跨度斜拉桥的真实性态的有限元模型,用于其结构健康监测状态的有效评估。为此以大跨度桥梁的静动力实测结果为依据,对大跨度斜拉桥初始有限元模型进行模型修正,保证计算结果与实测的结果基本吻合,在此基础上建立适用于大跨度斜拉桥长期健康监测的基准有限元模型。本文以广州鹤洞大桥长期结构健康监测为背景,采用基于时、频域的系统参数辨识方法,对大跨度斜拉桥的拉索索力和实测加速度信号进行信号分析,获得斜拉桥预拉力及主体结构相关的结构动力特征参数;探索了利用大型通用有限元SAP2000应用程序接口(API)的Matlab开发环境,进行后续有限元模型修正等方面的研究。为此本文主要展开了以下几个方面的工作:首先利用广州鹤洞大桥长期结构健康监测数据,分析了斜拉索的索力、桥面振动特性。建立了识别拉索基频辨识的MATLAB工具箱,运用自互谱法、随机子空间法及无线监测系统对桥面振动特性进行了分析。获得了现阶段广州鹤洞大桥的部分索力及前几阶振型的实测动力特征(固有频率、振型、阻尼),并将时域与频域法识别结果进行了对比,最后还与ARTeMIS软件分析结果进行了校核。参照广州鹤洞大桥工程设计施工图纸,截面物理属性,建立了与其对应的SAP2000初始有限元模型,通过反复调整模型参数,直至使得初始模型在恒载和索力作用下桥面线型与该桥的成桥线型,计算索力与实测索力基本吻合,在此基础上建立了大跨度斜拉桥基于索力测试的鹤洞大桥初始修正模型。对鹤洞大桥初始修正模型进行了模态分析,得出了其前20阶振型的自振频率及三维振型图;分析了不同参数(斜拉索的不同类型有限元单元模拟、弹性模量、边界条件及边墩等)对大跨度斜拉桥结构动力特征的影响。得出影响结构动力特性的几个重要参数,为大型斜拉桥有限元模型修正的目标函数、灵敏度分析研究提供了依据。最后将有限元分析结果与实测结果进行了对比,初步得到用于广州鹤洞大桥结构健康监测的基准有限元模型;并利用结构参数识别系统PARIS,结合其对UFC桥梁有限元模型修正的相关分析结果,探讨了有限元模型修正理论,采用敏感度分析和结构优化理论,研究广州鹤洞大桥结构健康监测基准有限元模型修正中的潜在应用。
[Abstract]:With the continuous development of bridge engineering design and construction technology, long-span cable-stayed bridges are emerging, and the stiffness of cable-stayed bridges becomes more and more flexible, which is very sensitive to the dynamic loads of wind and earthquake. Therefore, the requirements for structural health monitoring and damage identification of cable-stayed bridges are constantly raised, so it is necessary to establish a finite element model which can fully and accurately reflect the authenticity of long-span cable-stayed bridges and be used to effectively evaluate the structural health monitoring state of cable-stayed bridges. Based on the static and dynamic test results of long-span bridges, the initial finite element model of long-span cable-stayed bridges is modified to ensure that the calculated results are in good agreement with the measured results. On this basis, a benchmark finite element model for long term health monitoring of long span cable-stayed bridges is established. Based on the long term structural health monitoring of Guangzhou Hedong Bridge, the system parameter identification method based on time-frequency domain is used to analyze the cable force and the measured acceleration signal of the long-span cable-stayed bridge. The structural dynamic characteristic parameters related to the pretension force and the main structure of the cable-stayed bridge are obtained. The Matlab development environment of large universal finite element SAP2000 application interface (API) and the following finite element model modification are explored in this paper. The main work of this paper is as follows: firstly, the cable force and the vibration characteristics of the bridge deck are analyzed by using the long-term structural health monitoring data of Guangzhou Hedong Bridge. A MATLAB toolbox is established to identify the fundamental frequency of the cables. The vibration characteristics of the bridge deck are analyzed by using the self-cross spectrum method, the random subspace method and the wireless monitoring system. In this paper, some cable forces of Guangzhou Hedong Bridge and the measured dynamic characteristics (natural frequency, mode shape, damping) of the first few modes are obtained, and the identification results of time domain method and frequency domain method are compared. Finally, the results are checked with ARTeMIS software. Referring to the engineering design and construction drawings of Guangzhou Hedong Bridge and the physical properties of the section, the corresponding initial finite element model of SAP2000 is established, and the parameters of the model are adjusted repeatedly. Until the initial model is subjected to dead load and cable force, the initial modified model of Hedong Bridge based on cable force test is established. The modal analysis of the initial modified model of Hedong Bridge is carried out, and the natural frequency and three dimensional mode diagram of the first 20 modes are obtained. The influence of different parameters (finite element simulation of cable, elastic modulus, boundary condition and side pier etc.) on the dynamic characteristics of long-span cable-stayed bridge is analyzed. Several important parameters affecting the dynamic characteristics of the structure are obtained, which provide a basis for the objective function and sensitivity analysis of the finite element model modification of the large cable-stayed bridge. Finally, the results of finite element analysis are compared with the measured results, and the benchmark finite element model for structural health monitoring of Guangzhou Hedong Bridge is preliminarily obtained. Using the structural parameter identification system (PARIS,) combined with the related analysis results of the UFC bridge finite element model correction, the finite element model modification theory is discussed, and the sensitivity analysis and the structure optimization theory are adopted. The potential application of structural health monitoring benchmark finite element model modification of Guangzhou Hedong Bridge is studied.
【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
本文编号：2405046
[Abstract]:With the continuous development of bridge engineering design and construction technology, long-span cable-stayed bridges are emerging, and the stiffness of cable-stayed bridges becomes more and more flexible, which is very sensitive to the dynamic loads of wind and earthquake. Therefore, the requirements for structural health monitoring and damage identification of cable-stayed bridges are constantly raised, so it is necessary to establish a finite element model which can fully and accurately reflect the authenticity of long-span cable-stayed bridges and be used to effectively evaluate the structural health monitoring state of cable-stayed bridges. Based on the static and dynamic test results of long-span bridges, the initial finite element model of long-span cable-stayed bridges is modified to ensure that the calculated results are in good agreement with the measured results. On this basis, a benchmark finite element model for long term health monitoring of long span cable-stayed bridges is established. Based on the long term structural health monitoring of Guangzhou Hedong Bridge, the system parameter identification method based on time-frequency domain is used to analyze the cable force and the measured acceleration signal of the long-span cable-stayed bridge. The structural dynamic characteristic parameters related to the pretension force and the main structure of the cable-stayed bridge are obtained. The Matlab development environment of large universal finite element SAP2000 application interface (API) and the following finite element model modification are explored in this paper. The main work of this paper is as follows: firstly, the cable force and the vibration characteristics of the bridge deck are analyzed by using the long-term structural health monitoring data of Guangzhou Hedong Bridge. A MATLAB toolbox is established to identify the fundamental frequency of the cables. The vibration characteristics of the bridge deck are analyzed by using the self-cross spectrum method, the random subspace method and the wireless monitoring system. In this paper, some cable forces of Guangzhou Hedong Bridge and the measured dynamic characteristics (natural frequency, mode shape, damping) of the first few modes are obtained, and the identification results of time domain method and frequency domain method are compared. Finally, the results are checked with ARTeMIS software. Referring to the engineering design and construction drawings of Guangzhou Hedong Bridge and the physical properties of the section, the corresponding initial finite element model of SAP2000 is established, and the parameters of the model are adjusted repeatedly. Until the initial model is subjected to dead load and cable force, the initial modified model of Hedong Bridge based on cable force test is established. The modal analysis of the initial modified model of Hedong Bridge is carried out, and the natural frequency and three dimensional mode diagram of the first 20 modes are obtained. The influence of different parameters (finite element simulation of cable, elastic modulus, boundary condition and side pier etc.) on the dynamic characteristics of long-span cable-stayed bridge is analyzed. Several important parameters affecting the dynamic characteristics of the structure are obtained, which provide a basis for the objective function and sensitivity analysis of the finite element model modification of the large cable-stayed bridge. Finally, the results of finite element analysis are compared with the measured results, and the benchmark finite element model for structural health monitoring of Guangzhou Hedong Bridge is preliminarily obtained. Using the structural parameter identification system (PARIS,) combined with the related analysis results of the UFC bridge finite element model correction, the finite element model modification theory is discussed, and the sensitivity analysis and the structure optimization theory are adopted. The potential application of structural health monitoring benchmark finite element model modification of Guangzhou Hedong Bridge is studied.
【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
【参考文献】
相关硕士学位论文 前2条
1 于徐红;红枫湖大桥健康监测与评估系统数据处理的研究与实现[D];贵州大学;2007年
2 余成宝;火炮系统模态测试与分析[D];南京理工大学;2007年
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