环境温度对斜拉桥动力特性的影响分析

Effect Analysis of Environmental Temperature on Dynamic Properties of Cablestayed Bridge

摘要:

基于东海大桥健康监测系统测得的一年的环境温度和结构响应的数据,分析环境温度对结构动力特性的影响.首先,基于环境温度的监测数据对环境温度的分布特点进行分析,环境温度沿桥梁纵向具有较强的一致性,沿箱梁截面具有明显的温度梯度.接着对环境温度对结构动力特性的影响机理进行理论分析,并通过实际监测数据进行验证,表明理论分析与实际监测数据具有很好的一致性.最后,基于ARX模型对于环境温度对结构动力特性影响的惯性效应进行分析,表明环境温度的影响具有明显的时间滞后效应,同时基于多点温度能够等效表示环境温度的惯性效应.

Abstract:

Based on oneyear monitoring data measured by the structural health monitoring system of Donghai Bridge, the effect of environmental temperature on dynamic properties of cablestayed bridge was analyzed. At first, the distribution characteristics of environmental temperature were analyzed based on the monitoring data of environmental temperature. The environmental temperature was uniformly distributed along the longitudinal direction of bridge and there was also significant temperature gradient in the cross section of box girder. The influencing mechanism of environmental temperature on dynamic properties was theoretically analyzed and was validated by the monitoring data. The results demonstrate that the theoretical analysis is consistent with the monitoring data. Finally the thermal inertial effect of the environmental temperature on dynamic properties was analyzed based on AutoRegressive model with eXogenous inputs (ARX) model. The results show that there is time lag effect of temperature on dynamic properties and the time lag effect can be equivalently evaluated by multipoint temperature data.