风致静力扭角对桥梁颤振性能影响的节段模型试验研究  

Effect of wind-induced static torsional angle on flutter performance of bridges via sectional model test

作　　者：朱乐东[1,2,3] 朱青[1,2] 郭震山[2,3] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]同济大学桥梁工程系,上海200092 [3]桥梁结构抗风技术交通行业重点实验室,上海200092

出　　处：《振动与冲击》2011年第5期23-26,31,共5页Journal of Vibration and Shock

基　　金：科技部国家重点实验室基础研究资助项目(SLDRCE08-A-02);国家高新技术研究发展专项(863计划)经费(2006AA11Z120)联合资助

摘　　要：自由振动试验识别得到的气动参数已包含了一定的、但与实桥不严格相似的风致静力扭角的影响。为了在颤振分析中能精确考虑风致静力扭角的影响,首先必须消除节段模型试验中风致静力扭角对气动导数识别结果的影响。通过在试验过程中使节段模型作受控反向旋转可以消除平均风附加攻角,然后以象山港大桥为背景,将消除平均风附加攻角后的试验结果与常规试验结果相比较,对风致静力扭角对节段模型系统的阻尼比、气动导数和临界风速的影响进行了初步讨论。研究结果表明:风致静力扭角对模型扭转阻尼比和与扭转有关的气动导数有明显的影响。象山港大桥节段模型在+3°攻角发生颤振时风致静力扭角约为0.32°,攻角修正以后节段模型颤振临界风速识别结果提高了7%。Wind-induced static torsional angle has significant influence on results of a sectional model test.To accomplish accurate flutter analysis of bridges,wind-induced static torsional angle should be adjusted in a sectional model test.An attack angle control facility was used to eliminate static wind-induced additional attack angle.A comparison of test results before and after the attack angle adjustment on Xiang Shan Gang bridge showed that the static wind-induced additional attack angle has influence on aerodynamic torsional damping ratio,aerodynamic derivatives related to torsional movement and critical wind speed;before the adjustment,the static wind-induced additional attack angle of the sectional model of Xiang Shan Gang bridge under critical wind speed is about 0.32°with 3°initial attack angle;after the adjustment,the critical wind speed of the sectional increases by 7%.

关 键 词：风致静力扭角 阻尼比 颤振临界风速 气动导数 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]