基于振动响应二次协方差矩阵的服役桥梁环境振动健康监测方法研究

项目名称： 基于振动响应二次协方差矩阵的服役桥梁环境振动健康监测方法研究

项目编号： No.51208230

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 建筑环境与结构工程学科

项目作者： 李雪艳

作者单位： 暨南大学

项目金额： 25万元

中文摘要： 为了保证桥梁的安全营运，越来越多的新建和已建重要桥梁已安装了健康监测系统，本项目拟提出一种基于振动响应二次协方差矩阵（Covariance of Covariance ，CoC）的方法来分析这些桥梁在环境振动下的响应数据；即，将基于白噪声激励下推导出的CoC矩阵，推广到适用于包含车载、脉动风等有色噪声激励的环境振动下的数据分析和健康监测，由此矩阵建立新的损伤预警和判别指标，结合分析模型，对桥梁结构进行损伤定位和定量，并加以实验验证。本项目所提出的CoC矩阵方法能够充分利用到结构振动中的高阶模态信息，因而对损伤更敏感；同时，又避免了模态参数识别可能带来的误差和时域方法的系统定阶问题，以及对监测传感器布置要求过高的限制；计算简便快捷，不需人工参与，适合对海量连续数据进行自动在线分析，可为桥梁异常振动实时警报的实施提供技术支撑，不仅具有重要的学术理论意义，还具有很高的工程实用价值。

中文关键词： 二次协方差；环境激励；结构健康监测；损伤识别；系统识别

英文摘要： To ensure the safty of in-service bridges, increasing number of health monitoring system have been installed on new-built and existing large-scale bridges. In this project, a new method based on the matrix of covariance of covariance (CoC matrix) of structural vibration responses is developed, to analyze the vibration data and detect and quantify damages for in-service bridges under ambient excitations (including pink noise excitation). Based on the CoC matrix, a new damage parameter will be established to represent structural damage status. The CoC matrix makes full use of higher modes of structural modal information and thus the resulting damage parameter is more sensitive. In this method, errors from extracting modal parameters in the frequency domain methods and problems for determing the ranks of system in the time domain methods are avoided, and furthermore the high damand for sensor installment is not needed. The proposed method also have the advantage of easy computation and no manual operation is needed . Therefore, it is quite suitable for on-line analysis of huge amount of continuous vibration data of bridge health monitoring system. The outcome of this project will contribute to both damage detection theory and engineering application.

英文关键词： Covariance of Covariance；Ambient Vibration；Structural Health Monitoring；Damage Detection；System Identification