大跨径连续刚构桥缩尺模型工作状态时域信号段智能化选取方法研究

发布时间：2018-01-03 14:08

本文关键词：大跨径连续刚构桥缩尺模型工作状态时域信号段智能化选取方法研究　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：当前，国内外大跨径连续刚构桥应用广泛而又病害损伤频发，引起了工程界的广泛重视。本文以大跨径连续刚构桥为主要研究对象，在现有结构动力学、信号分析、声纹识别、结构模态识别、概率及统计学、结构损伤识别等理论基础上，加工制作缩尺桥梁模型，开展多种激励作用下桥梁结构基于加速度响应信号分段解析和声纹图谱的动力损伤识别研究，完成的主要工作如下。 ①根据相似比原理，设计、制作了黑冲沟大桥（左幅）缩尺模型；通过人工静力加载集中力，使模型桥主跨跨中产生底板横向自然裂缝，以模拟结构损伤状态。 ②完成模型桥各种结构状态在环境激励、锤击激励下加速度信号的采集和处理分析，建立原型和模型桥梁结构有限元仿真模型，对原桥实测数据、缩尺模型实测数据与有限元计算数据进行对比分析，对缩尺桥梁模型和有限元数值模型的有效性进行了验证。 ③针对缩尺桥梁模型的初始完好状态、开裂损伤状态及裂缝扩展状态等多个结构状态，分别开展不同质量、不同行驶速度的多个行车激励工况实验，获取模型结构关键部位加速度时程响应信号，采用信号时域分段频谱分析方法，构建基于加速度信号的结构动力响应声纹图谱，再利用分段频谱分析得到的频率点概率加权得到各工况下模型结构的指征频率。 ④基于结构损伤引起结构固有频率降低的概率意义，，利用模型桥梁在完好状态和损伤状态下各工况指征频率的统计特征，建立结构损伤识别的性能函数，利用性能函数的概率分布对结构损伤进行判断。
[Abstract]:At present, the long span continuous rigid frame bridge is widely used at home and abroad, with frequent damage and disease, which has attracted wide attention in the engineering field. In this paper, the long span continuous rigid frame bridge as the main research object, in the existing structural dynamics. Based on the theory of signal analysis, sound pattern recognition, structural modal identification, probability and statistics, structural damage identification, the model of scale bridge is fabricated. Dynamic damage identification of bridge structures under various excitations based on acceleration response signal segmentation and acoustic stripe is studied. The main work is as follows. 1. According to the principle of similarity ratio, the model of the scale of Heigonggou Bridge (left) is designed. By means of artificial static loading of concentrated force, the transverse natural cracks of the bottom plate are produced in the middle of the main span of the model bridge to simulate the damage state of the structure. (2) complete the collection and analysis of acceleration signal under the excitation of environment, and establish the prototype and finite element simulation model of the model bridge structure, and measure the actual data of the original bridge. By comparing the measured data with the finite element calculation data, the validity of the scale bridge model and the finite element numerical model is verified. (3) aiming at the initial intact state, crack damage state and crack spreading state of the scale bridge model, the experiments of driving excitation conditions with different mass and different driving speed are carried out respectively. The acceleration time-history response signals of the key parts of the model are obtained, and the structure dynamic response voice-pattern based on the acceleration signal is constructed by using the time-domain piecewise spectrum analysis method of the signal. Using the frequency point probability weighting obtained by piecewise spectrum analysis, the indicated frequency of the model structure under each working condition is obtained. Based on the probabilistic significance of structural natural frequency reduction caused by structural damage, the performance function of structural damage identification is established by using the statistical characteristics of the indicating frequency of the model bridge under the intact state and the damage state. The probability distribution of the performance function is used to judge the damage of the structure.
【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】：U448.23

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