典型窄基输电塔风致响应气弹模型风洞试验

首先,采用离散刚度法,设计制作了典型窄基输电塔气动弹性模型;然后,通过大气边界层风洞试验,对窄基输电塔不同高度及风向下的位移、加速度响应特性进行了测试分析;最后,基于风洞试验结果计算了窄基输电塔风振系数并与规范结果进行了比较。结果表明,窄基输电塔位移均值响应主要为顺风向;顺、横风向脉动位移、加速度响应值都较大,随风向变化不明显,呈上下波动趋势;高度变化对脉动位移和加速度的响应影响略有不同。此外,根据中国荷载规范给出的输电塔横担处的风振系数值大于本次试验结果。

Wind-Induced Responses Analysis for the Typical Transmission Tower with Narrow Base Based on an Aero-Elastic Model Wind Tunnel Test

Based on the discrete stiffness method, aero-elastic model for the typical transmission tower with narrow base (TTNB) was firstly made. Then the displacements and accelerations of the TTNB under various heights and wind directions were investigated through boundary layer wind tunnel tests. Finally, based on the wind tunnel test data, the wind-induced vibration coefficients of TTNB were calculated and compared with Chinese architectural structure load standards. The results showed that the mean displacements on the TTNB were mostly in the along-wind direction; but, the along-wind and across-wind fluctuating displacements and accelerations were in the same order of magnitude and cannot be ignored. Moreover, the fluctuating responses did not change remarkably with the variation of wind directions; however, the heights above ground had different influence on fluctuating displacements and accelerations. In addition, since the high-order modes had influence on the dynamic displacement responses, the wind-induced vibration coefficients which were only deduced from the first-order displacement response would be lower. And the wind-induced vibration coefficients obtained from Chinese architectural structure load standards were bigger than that from the wind tunnel tests.