Abstract:

The long-term wind-induced vibration would cause fatigue failure of high-rising columns in windy coastal areas. Therefore, a numerical method of wind-induced fatigue life calculation for high-rising columns was proposed, based on time-history simulation of random wind-induced stress responses, joint distribution model of wind speed and wind direction, rain-flow method and Miner fatigue cumulative damage rule. Then a typical example illustrated the method and indicates that serious fatigue damage or failure might will be induced by the long time empty conditions for this column, while the wind-induced fatigue life in the operating conditions can meet the design demand; cross-wind resonance is the decisive factor of wind-induced fatigue for this empty column, compared with the along-wind vibration producing the mainly fatigue damage in operating conditions caused by the strong wind. The difference of fatigue distribution curves that one with single peak and the other several peaks in the empty and operating conditions shows the along-wind fatigue damage is more concentrated than that of the cross-wind.

Key words: wind-induced vibration, fatigue life, high-rising column, wind load

摘要：

针对沿海多风地区高耸塔器可能因长期风致振动导致的疲劳问题，以随机风致应力响应的时程模拟、风速风向联合分布模型、雨流法以及Miner疲劳累积损伤理论为基础，提出了基于时域法的高耸塔器风致疲劳寿命数值计算方法，并针对某一典型高耸塔器进行了相关分析。结果表明：长时间的空塔工况可能导致该塔器严重的疲劳损伤甚至失效，而操作工况下的风致疲劳寿命一般可以满足设计年限要求;横风向共振是引起该塔器空塔工况风致疲劳的决定性因素，而强风造成的顺风向振动是导致其操作工况下疲劳损伤的主要原因;该塔器空塔和操作工况下的疲劳分布曲线分别呈多峰型和单峰型，可见顺风向的疲劳损伤比横风向更为集中。

关键词: 风振, 疲劳寿命, 高耸塔器, 风载荷