方智远1,汪之松1,2,李正良1,2.雷暴冲击风作用下高层建筑风荷载频域特性[J].湖南大学学报:自然科学版,2020,(1):100~107
雷暴冲击风作用下高层建筑风荷载频域特性
Frequency Domain Characteristics of Wind Loads on High-rise Buildings under Thunderstorm Downburst
  
DOI:
中文关键词:  雷暴冲击风  高层建筑  功率谱  相关系数  相干函数
英文关键词:thunderstorm downburst  high-rise building  power spectrum  correlation coefficients  coherence function
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作者单位
方智远1,汪之松1,2,李正良1,2 (1. 重庆大学 土木工程学院重庆 4000452.山地城镇建设与新技术教育部重点实验室(重庆大学)重庆 400045) 
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中文摘要:
      为研究雷暴冲击风作用下高层建筑风荷载的频域特性,采用冲击射流装置模拟雷暴冲击风,对5个不同深宽比(D/B)的矩形高层建筑模型进行测压试验. 根据试验数据,对模型层风荷载功率谱、相关系数以及相干性进行了详细分析. 结果表明:阻力系数谱基本与顺风向风速谱保持一致,随着径向距离的增加,阻力系数谱的频带变宽,主频及能量逐渐减小;升力及扭矩系数谱随模型深宽比的增大而有所差异,但变化不明显,考虑主要是受雷暴风近地面特殊的湍流风场影响;径向距离和模型深宽比对层阻力系数的相关性影响较大,对升力和扭矩系数的相关性影响相对较小;层阻力系数相干性随频率的增大呈线性减小;层升力系数相干性在低频段保持平稳,而后呈指数衰减,层扭矩系数相对较小,且随频率的增大而按指数率迅速衰减.
英文摘要:
      In order to study the frequency domain characteristics of wind loads on high-rise buildings under downburst,using the impinging jet device to simulate thunderstorm downburst,pressure test was carried out on rectangular high-rise building models with different aspect ratios(D/B). According to the test data,the power spectrum densities,correlation coefficients and coherence were analyzed in detail. The results show that the drag coefficient spectra are consistent with those of longitudinal wind spectrum of oncoming wind. With the increase of radial distance,the bandwidth of the drag coefficient spectrum becomes wider,and the main frequency and energy gradually decrease. The lift and torque coefficient spectra vary with the increase of the aspect ratio of the models,but the change is not obvious,which may be mainly affected by the special turbulent wind field of thunderstorm downburst. The radial distance and the aspect ratio have greater influence on the correlation of the drag coefficient,but less on the correlation of the lift and torque coefficients. The coherence of layer drag coefficient decreases linearly with the increase of frequency. The coherence of layer lift coefficient keeps stable in low frequency band,and it decreases exponentially with the increase of frequency. The layer torque coefficient is relatively small,and it decreases exponentially with the increase of frequency.
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