【摘要】 给出了台风"韦帕"经过时,在典型的农村地貌上进行的多点边界层风特性以及风致输电塔振动的实测结果。基于风速数据,重点分析了风特性各项参数的空间均匀性,包括平均风速和风向、风剖面参数、湍流强度、阵风因子、湍流积分尺度和脉动风谱、竖向衰减系数以及水平相干性。采集了输电塔横担和塔头塔身连接处垂直线路方向的振动加速度。基于振动数据,应用Hilbert-Huang变换(HHT)方法识别了输电塔垂直线路方向第1、2阶模态的自振频率和阻尼比。结果表明,自振频率识别结果与有限元计算结果比较接近,阻尼比识别结果远大于一般钢结构的阻尼比。更多还原

【Abstract】 The multi-points field measurement results of boundary layer wind characteristics over typical country terrain and wind-induced response of transmission tower during the passage of typhoon Wipha were presented.Detailed analyses of the wind speed were conducted to investigate the spatial homogeneousness of wind field during windstorms.The measured wind data were analyzed to compare the information on mean wind speed and wind direction,wind profile parameters,turbulence intensity,gust factor,turbulence integral length scale and spectra of fluctuating wind,vertical decay factor and horizontal coherence.Besides the wind speed,lateral wind-induced acceleration responses at the middle and the top of the 43-meters high transmission tower were measured.Based on the field measurements,the natural vibration frequencies and damping ratios of the first two lateral vibration modes were identified by Hilbert-Huang transform(HHT).The results show that identified results of natural vibration frequencies are well matched with those of finite element method calculation,and identified results of damping ratios are more greater than that those of general steel structures.更多还原