【作者】 吕宇超； 操金鑫； 赵祖军； 葛耀君；

【Author】 Lv Yuchao;Cao Jinxin;Zhao Zujun;Ge Yaojun;State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University;Department of Bridge Engineering,Tongji University;Sichuan Communication Surveying & Design Institute;

【机构】 同济大学土木工程防灾国家重点实验室； 同济大学桥梁工程系； 四川省交通运输厅规划勘察设计研究院；

【摘要】 基于同济大学土木工程防灾国家重点实验室TJ-5多风扇主动控制风洞,调试得到了一系列湍流强度和积分尺度连续变化的宽带和窄带来流湍流风场。利用这些流场,通过节段模型测振风洞实验,分别探究了湍流强度和积分尺度对典型闭口箱梁气动特性的影响。研究结果表明,湍流对闭口箱梁的颤振有显著的影响,颤振导数的各个分量随着湍流强度或积分尺度的增加均有变化,且程度不同;颤振临界风速也受到来流湍流的影响,小湍流强度下颤振临界风速有小幅提高,而大湍流强度下临界风速显著降低;闭口箱梁的颤振临界风速对湍流积分尺度的变化并不敏感。更多还原

【Abstract】 As one of the most advanced experimental tools to reproduce the natural turbulence,a newly-built actively-controlled multi-fan wind tunnel facility,TJ-5 wind tunnel,was employed to investigate the turbulence effects on flutter derivatives and critical wind speeds of typical close box girder bridge deck in this paper,through the sectional model test approach and the free-vibration identification method for flutter derivatives.The simulation of turbulent flow fields including narrow-band and wide-band ones with diverse turbulence intensities and integral length scales is achieved,which is difficult for grid-generated turbulence in conventional boundary layer wind tunnels.The results tend to indicate that turbulence has significant effects on this deck section,meanwhile turbulence intensity and integral length scale each has respective influence on flutter oscillations of bridge decks.The general conclusion is that each component of derivatives engages different levels of turbulence influence.And it is found that the critical wind speeds under small turbulence intensities are a bit larger than those under the smooth flow,yet under large turbulence intensities the critical speeds reduce rapidly.With the increase in integral length scales,the flutter critical wind speed seems not change much.更多还原