流线型箱梁涡激振动的气动力演化规律  

EVOLUTIONARY OF AERODYNAMIC CHARACTERISTICS AROUND STREAMLINED BOX GIRDER DURING VERTICAL VORTEX-INDUCED VIBRATION

作　　者：韩原 李震 王仰雪 邵林媛 靖洪淼 刘庆宽 HAN Yuan;LI Zhen;WANG Yang-xue;SHAO Lin-yuan;JING Hong-miao;LIU Qing-kuan(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang,Heibei 050043,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province,Shijiazhuang,Hebei 050043,China)

机构地区：[1]石家庄铁道大学土木工程学院,河北石家庄050043 [2]石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室,河北石家庄050043 [3]河北省风工程和能源利用工程技术创新中心,河北石家庄050043

出　　处：《工程力学》2023年第S01期108-112,共5页Engineering Mechanics

基　　金：国家自然科学基金项目(51778381);科技冬奥专项项目(21475402D);河北省高端人才项目(冀办[2019]63号);河北省青年科学基金项目(E2021210063);河北省研究生创新项目(CXZZBS2023136)。

摘　　要：涡激振动是大跨度流线型箱梁桥在低风速下常见的风致振动形式,对桥梁结构的疲劳寿命和行车舒适性有较大影响。为揭示流线型箱梁涡激振动机理,有必要研究其涡激振动的气动力演化规律。以某流线型箱梁桥为对象,通过同步测振测压的风洞试验方法,获得了+5°风攻角下主梁模型的涡激振动响应及表面测点风压时程,对比分析了涡激振动前、涡激振动振幅上升区、涡激振动振幅极值点、涡激振动振幅下降区和涡激振动后五个不同阶段模型表面的平均风压系数、脉动风压系数和涡激力的变化规律。结果表明:在涡激振动的不同阶段,流线型箱梁表面平均风压系数变化不大,而脉动风压系数分布具有明显的演化过程。涡激力在涡激振动振幅上升区、涡激振动振幅极值点及涡激振动振幅下降区有明显的卓越频率,且与结构自振频率相近,涡激振动前和涡激振动后无明显卓越频率。涡激力卓越频率对应的振幅与涡激振动位移振幅正相关,两者同在涡激振动振幅极值点处达到最大。The vortex-induced vibration(VIV)is a common form of wind-induced vibration of long span streamlined box-girder bridge under low wind speed.It has a great influence on the fatigue life and driving comfort of a bridge structure.In order to reveal the VIV mechanism of a streamlined box girder,it is necessary to study the aerodynamic evolution law of VIV of a streamlined box girder.Taking a streamlined box-girder bridge as an example,a wind tunnel test was conducted to obtain the VIV response and pressure time-history data from pressure measurement points on the experimental model for the angles of attack+5°.The changes of mean values of wind pressure coefficient,of root-mean-square(RMS)values of wind pressure coefficients and,of vortexinduced force(VIF)amplitude spectrum in different vortex-induced stages are analyzed.Those stages include pre-VIV stage,ascent stage,extreme amplitude point,descent stage,and post-VIV stage.It is found that mean values of wind pressure coefficients have little change,however,the distribution of RMS values of wind pressure coefficients has obvious changes.The VIF has obvious predominant frequencies in the ascent stage,at the extreme amplitude point,and in the descent stage.These frequencies are similar to the natural vibration frequency of the structure.However,there is no considerable predominant frequency in pre-VIV stage and post-VIV stage.The amplitude corresponding to the dominant frequency of VIF is positively correlated with the amplitude of VIV and reaches the maximum at the extreme amplitude point.

关 键 词：流线型箱梁 风洞试验 涡激振动 气动力 演化规律 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]