三边形桅杆风荷载谱模型试验研究

对三边形格构式桅杆进行了均匀流和两种紊流下的高频测力天平风洞试验,得到了顺风向、横风向和扭转向的气动力系数以及脉动风荷载谱。采用基于风速谱的数学模型对顺风向脉动风荷载谱进行拟合,验证了该经验公式在不同流场下的适用性。根据试验所得横风向和扭转向脉动风荷载功率谱曲线的特点,建立由紊流激励和旋涡脱落激励两部分组成的谱函数数学模型,最小二乘法拟合结果与风洞试验结果吻合良好。横风向脉动风荷载谱以紊流激励为主,紊流强度15%时旋涡脱落激励贡献仅占10%,扭转向脉动风荷载谱中旋涡脱落激励贡献明显增大,达到40%。

Experimental investigation on the mathematical models of wind load spectrum for triangular lattice mast

High frequency force balance test was conducted on triangular lattice mast and the along-wind, across-wind and torsional wind load spectra and mean force coefficients were obtained. The mathematical model based on the wind velocity function was used for the curve fitting of the along-wind load spectra and the applicability of the empirical formula in different flow fields was verified. Mathematical model consisted of turbulence and wake excitation was established for the across-wind load and torsional wind load according to the characteristics of the test spectra. Fitting results of least square method showed that the mathematical models were in good agreement with the test results. The contribution of turbulence excitation was dominant in across-wind load and the proportion of wake excitation was only 10% when the turbulent intensity was 15%. In torsional wind load the contribution of wake excitation increased obviously and accounted for about 40%.