风荷载作用下的输电塔线结构属于非线性耦合振动体系,自然风的脉动分量使体系中的构件处于交替受力状态,从而可能导致构件的疲劳破坏.文中以某直流线路的一段塔线体系为例,提出了输电塔线体系的风振疲劳时域分析方法;采用AR模型产生了随机风场,对输电塔线耦合体系进行了非线性风振时程分析;建立了考虑风向和风速分布等因素影响的疲劳累积损伤计算公式;确定了输电塔结构中疲劳损伤的关键部位,针对关键部位进行了应力分析,并采用线性累积损伤理论对构件的风振疲劳寿命进行了评估.结果表明,文中提出的时域分析方法可有效估算输电塔结构在风振作用下的剩余寿命.

The transmission tower-line structure under wind loads is a nonlinear coupled vibration system.Its members alternately undergo reversal stress due to the flutter component of the natural wind,which may result in the fatigue damage of the structure.In this paper,with a direct-current transmission line as a case,a method to analyze the wind-induced fatigue in time domain is proposed for the vibration of transmission tower-line system.Then,the random wind field is simulated by using the AR model,and the nonlinear time-history wind-induced vibration of the tower-line coupling system is analyzed.Moreover,an equation to calculate the fatigue cumulative damage affected by the distributions of wind direction and speed is established,and the dangerous members with potential fatigue cumulative damage are determined,followed by a detail stress analysis.Finally,the fatigue life of the members under wind loads is estimated based on the linear cumulative damage theory.It is found that the proposed time-domain analysis method can effectively estimate the residual life of the transmission tower in wind-induced vibration.