论文部分内容阅读
大跨斜拉桥结构的振动特性随环境与运营条件的变化表现出时变的特征。本文对润扬大桥斜拉桥结构的实测加速度响应信号采用复模态指示函数法(CMIF法)进行了模态参数识别,在此基础上采用最大熵法对实测模态频率的不确定性进行了分析。分析结果表明,环境温度的变化对斜拉桥模态频率的影响是长期性的趋势,而交通荷载和风荷载对模态频率的影响则由于荷载的非平稳性呈现瞬时的颤动变化。采用最大熵法较好地改善了润扬大桥斜拉桥的环境模态频率识别效果,有效地减少了实测模态频率因车辆和风荷载随机因素影响的变异性。
The vibration characteristics of long-span cable-stayed bridge structure exhibit time-varying characteristics with the changes of environment and operating conditions. In this paper, modal parameters are identified by the complex modal indication function method (CMIF) for the measured acceleration response signals of the cable-stayed bridge structure of Runyang Bridge. On the basis of this, the maximum entropy method is applied to the uncertainty of the measured modal frequencies Analysis. The results show that the influence of environmental temperature on the modal frequency of cable-stayed bridge is a long-term trend, while the impact of traffic load and wind load on the modal frequency changes instantaneously due to the non-stationary load. The maximum entropy method is used to improve the environmental modal frequency identification effect of Runyang Bridge cable-stayed bridge, effectively reducing the variability of the measured modal frequencies due to random factors of vehicle and wind load.