摘要
由于大跨度柔性装饰拱的结构刚度低,风荷载作用下诱发结构抖振应力循环变化幅度大,相比普通桥梁形式更容易引起疲劳。以海南某大桥装饰拱结构为例,根据桥址的风速记录气象资料,统计常态风速的变化规律,利用时域分析的方法,基于风速数值模拟进行抖振时程分析获得不同风速下拱结构的应力时程,采取雨流循环计数法进行统计分析得出应力幅的概率分布规律,并联系年风速的统计变化规律采用Miner线性累积损伤理论对结构进行疲劳性能评价。
Because of the low structural rigidity of long-spanned decorative arch,wind-induced buffeting stress cycle amplitude varies largely,which can cause structure fatigue more easily than other ordinary bridges.This paper takes a long-spanned decorative arch in Hainan as example,counts the variation of the normal wind speed according to the wind speed meteorological data at the bridge located site,and obtains the stress time-history of the arch structure under different wind speed by using the time-domain method based on the numerical simulation of wind speed.And then using the rain-flow counting method,we can get the probability distribution law of circulating stress amplitude by statistic analysis,and evaluate the structure fatigue performance by contacting the regularities of distribution of wind speed,using Miner linear cumulative damage theory.
引文
[1]Michel Virlogeux.Wind Design and Analysis for the Normandy Bridge.Aerodynamics of Large Bridge,A.Larsen(ed.)SETRA,Bagneux,France,1992.
[2]陈艾荣,陈华婷,项海帆.大跨度桥梁风致抖振疲劳可靠度近似分析及寿命估算[J].土木工程学报,1999,32(3):28-33.
[3]MASAO H,HIROSHI K,YOSHINOBU N.Fatigue strength design for vortex-induced oscillation and buffeting of a bridge[J].Journal of Wind Engineering and Industrial Aerodynamics,1997,67-68:227-237.
[4]陈礼忠.大跨度桥梁抖振疲劳分析方法的研究[D].上海:同济大学,1996.
[5]胡亮,李黎,彭元诚,樊剑.大跨桥梁抖振时域分析的程序化方法[J].中国公路学报,2006,19(6):59-64.
[6]韩万水,陈艾荣,胡晓伦.大跨度斜拉桥抖振时域分析理论实例验证及影响因素分析[J].土木工程学报,2006,39(6):66-71.
[7]Chen X,Kareem A.Equivalent static wind loads for buffeting response of bridges[J].Journal of Structure Engineering,ASCE,2001,127(12):1467-1475.
[8]陈艾荣,胡晓伦,韩万水.杭州湾跨海大桥抗风性能研究报告[R].上海:同济大学,2004.
[9]JTG/T D60-01-2004公路桥梁抗风设计规范[S].
[10]曹映泓,大跨度桥梁非线性颤振和抖振时程分析[D].上海:同济大学桥梁工程系,1999
[11]丁泉顺,大跨度桥梁耦合颤抖振响应的精细化分析[D].上海:同济大学桥梁工程系,2001.