桥梁实测频率的温度影响分析

Analysis and Correction Method of Temperature Influence on Measured Frequency of a Bridge

基于桥梁健康监测系统的实测数据,研究了桥梁实测频率的温度影响规律,结果表明桥面实测频率在一天内呈周期变化,且总体趋势随温度升高而降低,但桥面频率时程曲线与温度时程曲线有时存在相位差。利用有限元模型分析了桥梁温度变化与频率变化的内在影响机理,结果表明温度导致的弹性模量的改变对频率的影响占主导地位,温度变化量与频率变化量近似成线性关系,并且有限元模拟的频率的温度影响趋势与实测数据的温度影响趋势一致。

Based on measured data from the bridge health monitoring system,the regularity of temperature influence on measured frequency of this bridge was discussed.The result showed that the measured frequency of bridge deck changed periodically during a day and the average trend of frequency rose alone with the rise of the ambient temperature,but sometimes there was phase difference between the time-history of frequency of bridge deck and that of temperature.The internal influence mechanism of temperature on frequency of bridge was analyzed through finite element model,the result showed that the influence of temperature on frequency through elastic modulus played a great role among other factors,the change of frequency had linear relationship with the change of temperature,and the temperature influence trend of frequency from finite element simulation acted in accord with that from measured data.