摘要
介绍风速时程模拟方法,特别针对谐波合成法进行论述。以赤石特大桥为例,采用Fluent软件进行-4°～4°攻角范围内特定截面的三分力系数模拟分析,结果表明,当攻角为1°时,阻力系数最大。根据现场采集的风速样本,针对5号塔进行抗风时程分析,研究结果表明:采用不同的计算标准,动力系数结果并不一致,甚至当以横桥向弯矩为标准,脉动风荷载作用下索塔没有表现出动力放大效应;在桥面脉动风荷载作用、塔顶脉动风荷载作用下,塔顶的最大位移、索塔底部最大应力均在容许范围之内;索塔横桥向刚度远大于顺桥向,抗风分析应以顺桥向为主;采用不同的标准计算动力系数结果不同,进行拟静力分析时建议采用动力系数的最大值。
Wind speed time history simulation methods has been discussed first in this paper,especially for the harmonic synthesis method introduced in detail.Second,taking Chishi super large bridge for example,choosing a particular section,three-component coefficient simulate analysis between-4°and 4°has been carried out with the Fluent software,the results show that when the Angle of attack is 1°,drag coefficient reached maximum;Finally,according to measured wind speed samples,time history curves of wind speed for bridge deck and top of tower have been obtained,and time history analysis of wind-resistant for No.5 tower has been carried out.The results show that dynamic coefficients are different with different calculation standard,and even take bending moment cross the bridge for the standard,pulsating wind load does not show a dynamic amplification effect;Under pulsating wind loads at bridge deck or top of the tower,the maximum displacement at the top of the tower and maximum stress at the bottom of the tower are within the allowable range;The stiffness of lateral direction is far greater than that of longitudinal direction,therefore wind-resistant should be give priority to that of longitudinal direction.Dynamic coefficient result is obtained by different standards,maximum power coefficient is recommended for pseudo-static analysis.
作者
孟阳君
张家生
MENG Yangjun;ZHANG Jiasheng(Hunan University of Arts and Science,Changde 415006,China;School of Civil Engineering,Central South University,Changsha 410075,China)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2019年第1期121-128,共8页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(50978258)
湖南省教育厅一般项目(16C1091)
关键词
三分力系数
风速时程模拟
谐波合成法
抗风时程分析
稳定性
three-component coefficient
wind speed time series simulation
harmonic synthesis
wind-resistant time history analysis
stability
