海上风机在三种风载荷作用下的疲劳分析方法研究

文章提出一种基于等效疲劳载荷的快速有效的结构优化设计方法,首先通过bladed模拟得到时域下的风载荷,然后通过雨流计数法则和等效损伤理论得到相应的疲劳载荷谱和等效疲劳载荷,接着以导管架式海上风机为例,利用AN-SYS对其进行三维建模,选取三种典型管节点和两种非管节点,基于热点应力法计算了其在三种风疲劳载荷作用下的疲劳损伤,通过比较三种载荷作用下的疲劳损伤结果,验证了等效疲劳载荷的可靠性.接着又计算了各等效疲劳载荷分量单独作用下的海上风机焊接节点的疲劳损伤,得出各疲劳载荷分量对疲劳总损伤的贡献,可以为设计者提供更好的载荷设计依据.相比于传统的时域疲劳分析方法和疲劳载荷谱方法,等效疲劳载荷方法更加方便有效.

Fatigue Analysis for Welded Joints of Offshore Wind Turbine under Three Wind Loads

Fatigue damage of offshore wind turbines (OWT) is calculated with the hot-spot stress ap-proach, considering three different loads which include time domain loads, fatigue load spectrum and equivalent fatigue loads. Three tubular joints and two non-tubular joints are taken as the typical structure elements for study. By comparing with the results of fatigue damage under three loads, it is concluded that the damage under fatigue load spectrum is the largest, followed by that under equiv-alent fatigue loads, and the damage under time domain loads is the smallest. From the design point of view, the results calculated by fatigue load spectrum and equivalent fatigue loads can be consid-ered as conservative and safe. The equivalent load method shows a large advantage to check the fa-tigue damage of offshore wind turbine structures. It is convenient and not time-consuming. In addi-tion, the weight of six fatigue components of the equivalent fatigue loads is analyzed, which is con-venient, effective and fast for the optimization design of the support structure.