海上张力腿式风机支撑结构疲劳载荷特性研究

采用风机正向设计软件SAMCEF for Wind Turbine(S4WT),考虑风载荷和波浪载荷的联合作用,对海上张力腿式风机支撑结构疲劳载荷进行研究。首先,对支撑结构进行动力响应分析,得到风、浪联合作用下的疲劳载荷时程曲线,并采用雨流计数法得到疲劳载荷谱。然后,基于线性疲劳累积损伤理论求出对应的等效疲劳载荷。最后,分析相同风速下不同湍流强度等级对疲劳载荷的影响。计算结果表明:对支撑结构疲劳寿命影响最大的疲劳载荷为塔基处的倾覆力矩。风载荷和波浪载荷联合作用下的等效疲劳载荷并不是二者单独作用下的等效疲劳载荷的简单线性叠加,而是介于二者之间。湍流强度每升高一个等级,等效疲劳载荷基本上增加10%左右。

Study on fatigue loading characteristics of supporting structure for offshore wind turbine on tension-leg platform

With the forward design software——SAMCEF for Wind Turbine（S4WT），the fatigue load of the supporting structure for the offshore wind turbine on tension leg platform is studied herein under the consideration of the combined effect of wind load and wave load. Firstly，the dynamic response of the supporting structure is analyzed，and then the time-history curve of the fatigue load under the combined effect from wind and wave is obtained，while the relevant fatigue load spectrum is got as well. Secondly，the corresponding equivalent fatigue load is found out based on the linear fatigue accumulative damage theory. Finally，the impacts from the different turbulence intensity levels on the fatigue load under same wind spees are analyzed. The calculation results show that the fatigue load with maximum impact on the fatigue life of the supprting structure is the overturning moment at the tower foundation.The equivalent fatigue load under the combined effect from both the wind load and the wave load is not a simple linear superposition of the equivalent fatigue loads under their individual effects，but is just between them. Furthermore，the equivalent fatigue load is basically increased by about 10% along with every rising of the turbulence intensity up to one level.