雷暴风作用下流线型箱梁抖振力空间相关性时变特性试验  

Experimental Investigation of the Time-varying Characteristics of the Spanwise Correlation of Buffeting Force on Streamlined Box Girders Subjected to Thunderstorms

作　　者：李少鹏[1,2] 李鑫[1,2] 杨庆山 曹曙阳[3] 彭留留 LI Shao-peng;LI Xin;YANG Qing-shan;CAO Shu-yang;PENG Liu-liu(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China;State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [3]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《中国公路学报》2023年第5期128-139,共12页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51978108,51720105005);中央高校基本科研业务费专项资金项目(2021CDJQY-025);111引智基地(B18062)。

摘　　要：为了研究雷暴风作用下流线型箱梁断面抖振力空间相关性的时变特性,通过多风扇主动控制风洞开展雷暴风物理模拟和刚性节段模型测压试验。基于Priestley经典谱估计理论分析了非平稳脉动风和抖振力的时变相干函数,在此基础上,借鉴Jakobson研究成果提出了时变相干函数模型。最后,深入研究了紊流积分尺度时变特性对于抖振力空间相关性的影响,通过引入紊流三维效应因子的概念,揭示了雷暴风作用下流线型箱梁紊流三维效应的时变特征和作用机理。结果表明:雷暴风的时变积分尺度是影响流线型箱梁断面抖振力空间相关性时变特征的控制因素,由于该参数的引入,时变相干函数模型能够较好地描述非平稳抖振力的时变相关性;同时,当雷暴风在时变风速快速突变时,抖振升力的紊流三维效应时变特征明显,其变化趋势与积分尺度的时变规律相反,且存在一定的迟滞现象,其原因可能为风速突变产生的漩涡瞬态畸变效应导致。To study the time-varying characteristics of spatial correlation of buffeting force on streamlined box girder under thunderstorm wind,this study used a multi-fan active control wind tunnel to simulate a thunderstorm-like wind,and the rigid segment model pressure was measured.Priestley's spectrum estimation theory was used to investigate the time-varying coherence of nonstationary fluctuating wind and buffeting forces under the thunderstorm-like wind.The time-varying coherence function model is proposed based on the experimental results,referring to Jakobsen's research results.Finally,the effect of the time-varying characteristics of the integral length scale on the spatial correlation of buffeting force is deeply studied.By introducing the concept of the three-dimensional effect factor of turbulence,the time-varying characteristics and mechanism of the three-dimensional effect of turbulence of the buffeting force on a streamlined box girder due to thunderstorm-like wind can be revealed.The results indicate that the time-varying integral length scale of thunderstorm wind plays a significant role in determining the time-varying characteristics of the spatial correlation of buffeting forces on a streamlined girder.Because of introducing this turbulent parameter,the time-varying coherence model proposed herein can adequately describe the time-varying correlation of the buffeting force.Meanwhile,the time-varying feature of the three-dimensional effect of turbulence becomes more prominent when the time-varying mean wind velocity of thunderstorm-like wind changes rapidly.Compared with the integral length scale,the time-varying correlation of buffeting force has an opposite time-varying tendency.Notably,a certain time lag phenomenon is observed,which may be caused by the transient distortion of the vortices when the turbulent velocity changes rapidly.

关 键 词：桥梁工程 时变相干函数 Priestley谱估计理论 流线型箱梁断面 多风扇主动控制风洞试验 紊流三维效应时变因子 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]