基于三维 DICM 的非接触位移测试技术对导线气弹模型沿跨位移时程进行了测试,并对其进行统计与频谱分析,得到了导线风致位移的变化规律与概率分布特性。分析结果表明:导线在风荷载作用下,水平向振动表现为以一阶面外振型为主导、面内亦有一定贡献的振动形式,且随着风速的增加,面内振型的贡献也相应提高,从而使得导线在高风速下的面内振型的贡献不可忽略;对于竖向振动而言,其主导振型为面外一阶以及面内对称一、二阶;总体而言,在考虑导线风致响应时,选择包含面外一阶、面内一、二阶对称振型在内的三阶振型能够较为精确地反映其风致振动的主要能量组成;随着风速的增加,输电线面内、外非线性耦合程度增强,其风致响应不再满足高斯分布,位移响应峰因子应作相应调整。
Displacements along the transmission line were measured through the 3-D DICM (Digital image correlation method).Statistics and spectra of the wind-induced displacements were analyzed,and the results illustrated that under the wind loads,horizontal vibration of the transmission line is dominated by the first symmetric out-of-plane mode coupled with certain par-ticipation of in-plane mode,and as the wind speed increases,the contribution of in-plane mode become significant;as to the vertical vibration of the transmission line,the dominated modes in-clude the first symmetric out-of-plane mode,the first and second symmetric in-plane modes.O-verall,three modes mentioned above can be chosen to analyze the wind-induced vibration of the transmission line,which are sufficient to reflect the main components of wind-induced vibration energy;with the increasing of wind speed,the PDFs of the wind-induced displacements are non-Gaussian any more,and peak factors should be adjusted accordingly.