非流线型截面气动导纳识别的零点分离法

Aerodynamic Admittance Identification for Nonstreamline Section by Method of Zeroseparation

摘要:

抖振响应是大跨度桥梁风致振动研究中的一个重要部分,而气动导纳是抖振力表达式中的重要参数.目前,仅对于流线型截面存在气动导纳的解析表达式,而对于非流线型截面的气动导纳研究,尚处于探索阶段.利用静力三分力系数零值点,分离顺风向脉动风作用和横风向脉动风作用,分批识别6个气动导纳,即零点分离法.首次实现了6个气动导纳函数的完整识别,为气动导纳研究探索了一条新思路.其中，抖振力测量采用模型表面压力测量积分的方法,取得了良好的效果.

Abstract:

Buffeting response of a longspan bridge is an important part in the study of bridge vibration due to stochastic wind loads.Moreover,aerodynamic admittance functions are important parameters on buffeting force expression.At present,there is only an analytical expression for streamline section.The aerodynamic admittance for nonstreamline section is still on the exploration stage.This paper presents a zeroseparation method using the separated action of zero of steady state aerodynamic coefficient to orthogonal turbulence components to identify six aerodynamic admittances of the Scanlan’s modified buffeting force expression group by group.Six aerodynamic admittances are integral identified for the first time,which opens up a new way for aerodynamic admittance testing study.With the pressure measurement method,the stochastic buffeting force were measured with wind tunnel testing.