基于监测数据的斜拉索模态参数变异性分析

来源:用户上传      作者:周海俊 刘俊辉 杨夏 李婧超 张超东 孙利民

　　摘 要：基于某大跨斜拉 5根拉索1年的加速度和温度监测数据，系统分析了在良好天气和暴雨天气下拉索模态参数和索力的变化特征.使用快速傅里叶变换和随机子空间法识别模态频率和阻尼比.对比发现，暴雨天气下拉索振幅大，低阶模态的振动明显，模态阻尼比在两种天气下有一定的差异性.使用频率法计算得到了各拉索连续一年的索力值，其为非平稳时间序列，且具有年和日周期性的波动.索力-索温关系分析表明，各拉索索力-索温的关系各 不同，同一根拉索在不同温度范围内的索力-索温关系也可能存在很大的差异.使用半功率带 宽法计算得到了各拉索连续一年的阻尼比，得到了自相关函数和其自功率谱，并拟合得到了阻尼比的边缘概率密度分布函数.分析表明，各拉索阻尼比具有时长为1d、12h、6 h的周期成分，其边缘概率密度函数可用Burr分布描述.拉索的阻尼比受环境温度的影响较小，受车辆荷 载的影响较大.
　　关键词：拉索振动;监测数据;模态参数;索力;温度效应;变异性分析
　　中图分类号：U448.27，U448.14 文献标志码：A
　　Modal Parameter Variance Analysis of Stay Cable Based on Monitoring Data
　　ZHOU Haijun1，LIU Junhui2，YANG Xia1，LI Jingchao3，ZHANG Chaodong1?，SUN Limin4（1.Institute of Urban Smart Transportation & Safety Maintenance，Shenzhen University，Shenzhen 518060，China;
　　2.Shenzhen Water Group Co，Ltd，Shenzhen 518060，China;
　　3.College of Mathematics and Statistics，Shenzhen University，Shenzhen 518060，China;
　　4.State Key Laboratory for Disaster Reduction in Civil Engineering（Tongji University），Shanghai 200092，China）
　　Abstract：The time-varying characteristics of cable modal parameters and cable tensions under good weather and heavy rain are systematically analyzed based on the one-year acceleration and temperature monitoring data of five cables on a long-span cable-stayed bridge.The modal frequency and damping ratio are derived using the fast Fourier transform（FFT） and stochastic random identification（SSI） method.It is found that the cable vibratesgreatly under wind and rain conditions.The low-order mode dominates the vibration，and the modal damping ratio has certain differences in the two circumstances.The tension force of each cable throughout the year，derived using the frequency method，is a non-stationary time series and has annual and daily periodic fluctuations.The correlation analysis of the cable tension and temperature shows that the correlation between the two of each cable is different，even differs on the same cable in different temperature ranges.The half-power bandwidth method is used to calculate the damping ratio of each cable for one year，the autocorrelation function and its self-power spectrum are obtained，and the edge probability density distribution function of the damping ratio is also obtained by fitting.The analysis shows that the damping ratio of each cable has the periodic components of1day，12hours，and6 hours，and its edge probability density function can be described by Burr distribution.The damping ratio of the cable is less affected by the ambient temperature but more by the vehicle load.

nlc202208221031

转载注明来源:https://www.xzbu.com/4/view-15438037.htm