输电塔线耦合体系的风振疲劳时域分析

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.

Wind-Induced Fatigue Analysis in Time Domain for Transmission Tower-line Coupling System

The transmission tower-line structure is a nonlinear coupled vibrating system under wind load. Because of the flutter component of the natural wind, the members of the structure undergo alternately reversal stress, and they would have the fatigue cumulative damage. With the instance of a direct current power transmission line, a fatigue analysis method in time-domain is introduced for the vibration of transmission tower-line system which under wind-induced load. The random wind field is simulated by AR model, and nonlinear time-history wind-induced vibration of the tower-line coupled system is analyzed. The equation of calculating the fatigue cumulative damage is deduced with the effect of the distribution of the wind direction and speed. After confirming the dangerous members which potentially have fatigue cumulative damage and a detail stress analysis for these members, the fatigue life of the members under the wind-induced vibration is estimated based on the liner cumulative damage theory. The result shows that this method can effectively estimate the residual life of the transmission tower in the wind-induced vibration.