古建筑木结构模态分析方法对比研究

发布时间：2018-01-16 18:05

本文关键词：古建筑木结构模态分析方法对比研究　出处：《聊城大学》2017年硕士论文　论文类型：学位论文

【摘要】：模态分析技术一直是振动工程理论的基础和核心,尤其在土木工程领域的应用越来越广泛。但由于很多工程结构复杂且约束条件较多,导致结构在实际振动信号测量及提取过程中存在一定的困难。因此,选择合适的方法对结构进行模态参数识别激励着科技工作者不断探索,寻求更加有效的方法。古建筑木结构作为我国宝贵的物质文化遗产,在中华文明历史的长河中占有很重要的地位。但随着社会的进步,人们的生活发生了翻天覆地的变化,尤其是交通的发展尤为迅速。车流量的迅速增加给人们生活带来便利的同时,交通微振动对古建筑的影响也越来越明显。为了更好的保护古建筑,选择有效的模态分析方法来准确的识别结构的各项模态参数,为后续古建筑木结构的健康监测及损伤预测提供理论支持。因此,本文以聊城光岳楼为例,通过现场实测并对获取的原始数据进行预处理之后,采用环境激励法对光岳楼木结构进行试验模态分析。并分别采用时域法和频域法与试验模态分析结果进行对比,确定适合古建筑木结构的模态分析方法。主要研究内容如下:(1)光岳楼现场振动测试利用用泰斯特动态信号测试系统,确定测试方案,设置监测参数,进行测点布置,得到各测点速度时程曲线。并对实测的原始数据进行去直流、平滑、消除趋势项等相关处理。(2)光岳楼试验模态分析采用泰斯特模态分析软件对光岳楼进行试验模态分析,获得结构的自振频率、振型、阻尼比。同时根据《规范》相关公式进行计算,验证本次试验模态分析的结果是否准确。(3)模态分析方法研究对比采用MATLAB软件进行算法编程,选定参考点,分别采用时域法中的自然激励法、ITD法、复指数法(PREC法)、特征系统实现算法(ERA法)以及频域法中的峰值法进行模态参数识别,将识别结果与泰斯特试验模态模态分析方法进行对比,确定适合古建筑木结构的模态分析方法。
[Abstract]:Modal analysis technology has always been the foundation and core of vibration engineering theory, especially in the field of civil engineering, but because of the complexity of many engineering structures and more constraints. As a result of the structure in the actual vibration signal measurement and extraction process there are some difficulties. Therefore, choosing the appropriate method to identify the modal parameters of the structure encourages the scientific and technological workers to explore constantly. To seek more effective methods. As a valuable material and cultural heritage of our country, the wooden structure of ancient architecture occupies a very important position in the history of Chinese civilization. But with the progress of society. People's lives have undergone earth-shaking changes, especially the rapid development of traffic. The rapid increase in traffic flow to people's lives at the same time. In order to better protect the ancient building, the effective modal analysis method is chosen to identify the modal parameters of the structure accurately. It provides theoretical support for health monitoring and damage prediction of ancient building wood structure. Therefore, this paper takes Liaocheng Guangyue Tower as an example, through field measurement and pre-processing of the original data obtained. The experimental modal analysis of the wooden structure of the optical building is carried out by using the environmental excitation method, and the time domain method and the frequency domain method are used to compare the results with the experimental modal analysis results. The main research contents are as follows: 1) the field vibration test of the light tower using Tester dynamic signal test system, determine the test scheme, set the monitoring parameters. At the same time, the velocity time history curve of each measuring point is obtained, and the measured original data is dedirect current and smooth. Elimination of trend terms and other related treatment. 2) the experimental modal analysis of the optical building using Tester modal analysis software to obtain the natural vibration frequency and vibration mode of the structure. At the same time, the damping ratio is calculated according to the relevant formula, which verifies whether the results of modal analysis in this experiment are accurate or not. The comparison of modal analysis methods using MATLAB software is used to program the algorithm. The reference points are selected and the natural excitation method ITD method and complex exponential method (PREC method) are used respectively in the time domain method. The modal parameters are identified by the peak value method in the frequency domain method, and the results are compared with the modal analysis method of Tester test. The modal analysis method suitable for wood structure of ancient buildings is determined.
【学位授予单位】：聊城大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU366.2

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