桥梁断面抖振力理论模型及关键影响参数研究

The key parameters of buffeting force theory for bridge decks are aerodynamic admittance and coherence properties along span of buffeting force. But the achievements about aerodynamic admittance and coherence properties of buffeting force have obvious defects and the results obtained from this type of buffeting analysis are seriously deviate from the truth, it is a bottleneck on the wind induced vibration analysis of bridges and need to be broken through..This program to study the interaction mechanism of air and structure coupling of bluff body section, to establish mathematical model about aerodynamic admittance and buffeting force coherence function, and the precise identified method about aerodynamic admittance and coherence function. An active generation of gust in wind tunnel should be developed to produce the turbulent wind with large turbulence integral scale. On that basis, the wind field characteristics,especially turbulence integral scale influence on aerodynamic admittance and span coherence of buffeting force should be investigated and establish theoretical formulas for aerodynamic admittance and correlation properties of buffeting force in consideration of turbulence integral scale and bridge dimensions. the obvious defects of traditional bridge buffeting analysis mothed should be corrected which used sears function to be aerodynamic admittance and wind speed coherence replace buffeting force coherence . At last,the buffeting response analysis theory of large span bridge should be established.

桥梁断面抖振力理论模型的关键参数是气动导纳和抖振力跨向相关特性，但目前桥梁抖振分析中所用的气动导纳和抖振力跨向相关性存在明显缺陷，导致大跨桥梁抖振分析的结果与实际情况严重偏离，已经成为大跨桥梁风振分析研究方向上的一个瓶颈，亟待突破。.本课题首先从理论上研究钝体断面气固耦合的相互作用机理，建立钝体断面气动导纳和跨向相关函数的数学模型；研究精确的桥梁断面气动导纳和抖振力跨向相关函数的参数识别方法；研制能够产生大紊流积分尺度的紊流主动模拟装置；在此基础上，研究风速参数特别是紊流积分尺度对不同桥梁断面气动导纳和抖振力跨向相关特性的影响规律，建立考虑紊流积分尺度和桥梁断面特征尺寸的桥梁断面气动导纳和抖振力跨向相关函数的理论公式；修正传统上桥梁抖振分析以Sears函数作为气动导纳和以风速相关代替抖振力相关的明显缺陷，完善大跨桥梁抖振分析理论。

桥梁断面抖振力理论模型的关键参数是气动导纳和抖振力跨向相关特性，以前在模拟桥梁断面的抖振力时,由于不清楚桥梁断面的气动导纳和跨向相关特性，往往不考虑桥梁断面的气动导纳或者简单的视为Sears函数，将脉动风的跨向相关性看作桥梁抖振力的跨向相关性，导致大跨桥梁抖振分析的结果与实际情况严重偏离，制约了大跨特别是超大跨桥梁抖振分析的精确性，是目前桥梁抗风分析中亟待突破的关键问题。.本课题首先从理论上研究钝体断面气固耦合的相互作用机理，建立钝体断面气动导纳和跨向相关函数的数学模型；研究精确的不同桥梁断面气动导纳和抖振力跨向相关函数的参数识别方法；研制能够产生大紊流积分尺度的紊流主动模拟装置；在此基础上，研究风速参数特别是紊流积分尺度对不同桥梁断面气动导纳和抖振力跨向相关特性的影响规律，建立考虑紊流积分尺度和桥梁断面特征尺寸的桥梁断面气动导纳和抖振力跨向相关函数的理论公式；修正传统上桥梁抖振分析以Sears函数作为气动导纳和以风速相关代替抖振力相关的明显缺陷，完善大跨桥梁抖振分析理论。