空气动力学学报
空氣動力學學報
공기동역학학보
ACTA AERODYNAMICA SINICA
2014年
3期
351-359
,共9页
超高层建筑%风致响应%气动阻尼%气动弹性模型%风洞试验
超高層建築%風緻響應%氣動阻尼%氣動彈性模型%風洞試驗
초고층건축%풍치향응%기동조니%기동탄성모형%풍동시험
super-high-rise building%wind-induced acceleration response%aerodynamic damping%aero-elastic model%wind tunnel test
通过15个超高层建筑气动弹性模型的风洞试验，利用随机减量法从模型的风致加速度响应中识别了横风向气动阻尼比，并通过比较验证了识别结果的正确性。在此基础上，研究了矩形截面超高层建筑横风向气动阻尼的变化规律，考察了湍流度、高宽比、宽厚比对建筑结构气动阻尼比的影响。研究结果表明：来流湍流度和建筑的宽厚比是影响高层建筑横风向气动阻尼比至关重要的参数，而高宽比主要通过改变振动幅值来影响横风向气动阻尼；横风向气动阻尼比随折减风速变化的正负峰值大小基本随来流湍流度的增大而减小，气动阻尼比由正转负对应的折减风速随湍流度的增大而增大；宽厚比对横风向气动阻尼比的影响很大，当 B/D＜1、B/D＝1及 B/D＞1时，气动阻尼比的变化规律几乎完全不同。基于这些研究数据，对横风向湍流度为0．67％～17．06％的风场中、高宽比5～10及宽厚比1/3～3之间的矩形截面超高层建筑，给出了适用于低折减风速区的横风向气动阻尼比经验公式。
通過15箇超高層建築氣動彈性模型的風洞試驗，利用隨機減量法從模型的風緻加速度響應中識彆瞭橫風嚮氣動阻尼比，併通過比較驗證瞭識彆結果的正確性。在此基礎上，研究瞭矩形截麵超高層建築橫風嚮氣動阻尼的變化規律，攷察瞭湍流度、高寬比、寬厚比對建築結構氣動阻尼比的影響。研究結果錶明：來流湍流度和建築的寬厚比是影響高層建築橫風嚮氣動阻尼比至關重要的參數，而高寬比主要通過改變振動幅值來影響橫風嚮氣動阻尼；橫風嚮氣動阻尼比隨摺減風速變化的正負峰值大小基本隨來流湍流度的增大而減小，氣動阻尼比由正轉負對應的摺減風速隨湍流度的增大而增大；寬厚比對橫風嚮氣動阻尼比的影響很大，噹 B/D＜1、B/D＝1及 B/D＞1時，氣動阻尼比的變化規律幾乎完全不同。基于這些研究數據，對橫風嚮湍流度為0．67％～17．06％的風場中、高寬比5～10及寬厚比1/3～3之間的矩形截麵超高層建築，給齣瞭適用于低摺減風速區的橫風嚮氣動阻尼比經驗公式。
통과15개초고층건축기동탄성모형적풍동시험，이용수궤감량법종모형적풍치가속도향응중식별료횡풍향기동조니비，병통과비교험증료식별결과적정학성。재차기출상，연구료구형절면초고층건축횡풍향기동조니적변화규률，고찰료단류도、고관비、관후비대건축결구기동조니비적영향。연구결과표명：래류단류도화건축적관후비시영향고층건축횡풍향기동조니비지관중요적삼수，이고관비주요통과개변진동폭치래영향횡풍향기동조니；횡풍향기동조니비수절감풍속변화적정부봉치대소기본수래류단류도적증대이감소，기동조니비유정전부대응적절감풍속수단류도적증대이증대；관후비대횡풍향기동조니비적영향흔대，당 B/D＜1、B/D＝1급 B/D＞1시，기동조니비적변화규률궤호완전불동。기우저사연구수거，대횡풍향단류도위0．67％～17．06％적풍장중、고관비5～10급관후비1/3～3지간적구형절면초고층건축，급출료괄용우저절감풍속구적횡풍향기동조니비경험공식。
The mechanism of aerodynamic damping in cross-wind is very complicated.No widely adopted theory and sophisticated method are available up to date,with no relevant guidelines in the load standards and codes in most countries.In order to investigate the effects of roughness exposure,aspect ratio and side ratio on across-wind aerodynamic damping ratio,the random decrement technique is used to evaluate across-wind aerodynamic damping ratios from wind-induced acceleration responses of 15 aeroelastic models.The evaluated results are compared with previous research achievements.The characteristics of across-wind aero-dynamic damping ratio of rectangular high-rise buildings are studied.Results indicate turbulence intensity and side ratio are the most important factors affecting across-wind aerodynamic damping ratio.Aspect ratio indirectly affects aerodynamic damping ratio through making change of response amplitude.For the variation rule of aerodynamic damping ratio with reduced wind velocity,both of the magnitudes of positive and nega-tive peaks decrease as turbulence intensity increases.Meanwhile,reduced wind velocity,from which aerody-namic positive damping ratio changes to negative damping,increases as turbulence intensity increases.Side ratio has significant influence on across-wind aerodynamic damping ratio,and completely different tendency are observed for B/D <1,B/D =1 and B/D >1.According to the database,empirical aerodynamic damping functions are proposed to estimate aerodynamic damping ratios at low reduced velocities for rectangular su-per-high-rise buildings with an aspect ratio in the range of 5 to 10,a side ratio of 1/3 to 3,and lateral turbu-lence intensity varying from 0.67% to 17.06%.
