风浪联合下导管架式风机结构疲劳特性研究

Study on structural fatigue characteristics of jacket type wind turbine under combined wind and wave

针对导管架式风机在风浪环境下的疲劳损伤问题,文章设计了适用于40 m水深的简单导管架基础,并进行了疲劳损伤研究。该导管架基础满足NREL 5 MW风机对风机系统的一阶频率要求。文章开展了导管架式风机系统全耦合动力分析,研究了波浪引起共振时导管架基础主要管节点及塔筒底端的疲劳损伤,并对风浪异向的影响进行了分析。采用全耦合法、应力叠加和疲劳损伤叠加3种方法预报风浪联合作用下产生的疲劳损伤,并进行了对比分析。对比结果表明,疲劳损伤叠加法会严重低估风浪联合产生的疲劳损伤,而应力叠加法则因忽略风浪联合下的气动阻尼效应而略高估疲劳损伤。

A simple jacket foundation suitable for 40 m water depth is designed to study the fatigue damage under wind and wave environment.The jacket foundation meets the requirement of NREL 5 MW wind turbine about the fundamental modal frequency of the whole wind turbine system.By taking full coupled dynamic analysis,the fatigue damage of main jacket joints and the tower bottom end under wave induced resonance is studied,and the influence of wind-wave misalignment on the fatigue damage is analyzed.Three methods are used to predict the fatigue damage caused by the combination of wind and waves:full coupled analysis,stress superposition,fatigue damage superposition.The results show that the fatigue damage superposition method can seriously underestimate the fatigue damage,while the stress superposition method slightly overestimates the fatigue damage due to neglecting the aerodynamic damping effect of wind wave combination.