基于健康监测的矮塔斜拉桥动力特性温度影响研究

Study on the Influence of Temperature on the Dynamic Characteristics of Extradosed Cable-stayed Bridge Based on Health Monitoring

为研究温度对大跨矮塔斜拉桥动力特性的影响,以乌海黄河特大桥为研究对象,运用midas Civil计算该桥的动力特性值,通过MATLAB对健康监测系统得到的实测数据进行模态参数识别,并利用灰色关联原理分析温度与模态参数之间的关系。结果表明,采用NExT-FERA优化算法可以快速识别出桥梁的动力特性,且识别的模态正交性良好,无虚假模态;温度对于大跨矮塔斜拉桥的模态频率具有显著影响,两者呈现明显的负相关性,对于阻尼比和振型的影响程度明显较小,相关性较弱,验证了温度对大跨矮塔斜拉桥动力特性的影响。

In order to study the influence of temperature on the dynamic characteristics of long-span extradosed cable-stayed bridge,taking Yellow River Super-large Bridge in Wuhai City as the background,midas Civil was used to calculate the dynamic characteristics of the bridge,the modal parameters of the measured data obtained by the health monitoring system were identified by MATLAB,and the relationship between temperature and modal parameters was analyzed by using the grey correlation principle.The results show that the dynamic characteristics of the bridge can be quickly identified by using NExT-FERA optimization algorithm,and the identified modes have good orthogonality and no false.In addition,temperature has a significant impact on the modal frequencies of long-span extradosed cable-stayed bridge,and it shows an obvious negative correlation between temperature and modal frequencies.However,the influence on damping ratio and vibration mode is obviously small,and the correlation is weak.Therefore,it is verified that temperature has an impact on the dynamic characteristics of long-span extradosed cable-stayed bridge.