空气动力学学报
空氣動力學學報
공기동역학학보
ACTA AERODYNAMICA SINICA
2009年
6期
707-712
,共6页
气动导数%气动导纳%大跨桥梁%参数识别
氣動導數%氣動導納%大跨橋樑%參數識彆
기동도수%기동도납%대과교량%삼수식별
flutter derivative%aerodynamic admittance%bridge deck%parameter identification
气动导纳的准确估计对大跨桥梁抖振分析具有重要意义.目前在识别方法、试验技术等方面均有诸多进展,但尚未建立识别全部气动导纳函数的方法.针对这一问题,基于气动导数与气动导纳之间的关系,结合根据紊流风场中的抖振响应同时识别桥梁结构气动导数和气动导纳这一思路,首先采用随机子空间法识别得到紊流风场中桥梁结构的气动导数,然后利用气动导数与气动导纳之间的近似关系获取与竖向脉动风分量对应的气动导纳函数,最后根据抖振力谱和脉动风速谱来确定与水平向脉动风分量对应的气动导纳函数.实例研究表明,本文方法对流线型断面气动导纳的识别是可行的.
氣動導納的準確估計對大跨橋樑抖振分析具有重要意義.目前在識彆方法、試驗技術等方麵均有諸多進展,但尚未建立識彆全部氣動導納函數的方法.針對這一問題,基于氣動導數與氣動導納之間的關繫,結閤根據紊流風場中的抖振響應同時識彆橋樑結構氣動導數和氣動導納這一思路,首先採用隨機子空間法識彆得到紊流風場中橋樑結構的氣動導數,然後利用氣動導數與氣動導納之間的近似關繫穫取與豎嚮脈動風分量對應的氣動導納函數,最後根據抖振力譜和脈動風速譜來確定與水平嚮脈動風分量對應的氣動導納函數.實例研究錶明,本文方法對流線型斷麵氣動導納的識彆是可行的.
기동도납적준학고계대대과교량두진분석구유중요의의.목전재식별방법、시험기술등방면균유제다진전,단상미건립식별전부기동도납함수적방법.침대저일문제,기우기동도수여기동도납지간적관계,결합근거문류풍장중적두진향응동시식별교량결구기동도수화기동도납저일사로,수선채용수궤자공간법식별득도문류풍장중교량결구적기동도수,연후이용기동도수여기동도납지간적근사관계획취여수향맥동풍분량대응적기동도납함수,최후근거두진력보화맥동풍속보래학정여수평향맥동풍분량대응적기동도납함수.실례연구표명,본문방법대류선형단면기동도납적식별시가행적.
Accurate estimation of aerodynamic admittance functions for large-span bridges is of critical importance to ensure the reliability of buffeting analysis. Although much progress has been achieved both in the identification and testing methodologies of aerodynamic admittance functions, complete aerodynamic admittance functions can not be extracted in grid or boundary turbulence. In this paper, based on the relationships between flutter derivatives and aerodynamic admittance functions, a new method has been proposed to identify the complete aerodynamic admittance functions. The method was experimentally verified by wind tunnel tests, which were conducted to experimentally determine the flutter derivatives and aerodynamic admittance functions of a streamlined thin plat model. However, for bluff body, the feasibility of the present method could not be recognized.