摘要
温度作为一项重要的环境输入,对桥梁结构状态的影响是不容忽视的。以东海大桥健康监测数据为工程背景,对大气温度、结构温度和跨中挠度数据的相关分析和相干分析,结果表明:结构温度与大气温度以及桥梁跨中挠度与大气温度具有明显的时间滞后效应,且通过功率谱分析发现挠度数据对结构动力响应不敏感,主要能量集中在低频部分。采用可以计入时滞效应的ARX模型建立跨中挠度与大气温度之间的互相关模型,并用其预测由温度作用产生的跨中挠度,通过与实测值对比对模型进行了验证,结果表明此模型可以很好地描述模拟温度与跨中挠度之间非线性关系。此模型可将温度作用产生的挠度值从总挠度中分离出来,为挠度评估奠定基础。
As an important environmental factor, the influence of temperature on bridge structure cannot be ignored. By using the monitoring data of the Donghai Bridge, this paper analyses the correlation and coherence among atmospheric temperature, structure temperature and mid-span deflection data. The result shows that there are significant time lag effects existing between the structure temperature and the atmospheric temperature as well as between the bridge mid-span deflection and the atmospheric temperature. Also, the power spectrums analysis indicates that the deflection data is not sensitive to the structural dynamic response and the main energy is concentrated in low frequency mode. Adopting ARX model which can consider the effects of time lag, the cross-correlation model of mid-span deflection and atmospheric temperature is established, and can forecast the mid-span deflection caused by the temperature action. By comparing with the measured value, the model is validated. The result shows that this model can effectively simulate the nonlinear relation between temperature and mid-span deflection of a cable-stayed bridge. This model can separate the deflection value caused by temperature from the total deflection, which lays a foundation for bridge deflection assessment.
出处
《城市道桥与防洪》
2013年第12期66-69,10,共4页
Urban Roads Bridges & Flood Control
关键词
健康监测
ARX模型
温度
跨中挠度
structural health monitoring(SHM),ARX model,temperature,mid-span deflection.
