插环式风机基础疲劳损伤机理研究

Fatigue damage mechanism of wind turbine foundation with foundation pipe

通过对国内多台问题风机基础进行现场勘查和基础环水平度,混凝土强度及基础环下法兰视频探测等,分析了插环式风机基础的风致疲劳损伤。结果表明插环式风机基础疲劳损伤形成及演变主要包括3个阶段,即主风向初始裂缝;裂缝扩展至下法兰,下法兰松动导致其周边混凝土经研磨形成空腔,上穿环孔内及周边混凝土压溃;随着下法兰周边空腔的加大,基础环因上下位移加大而导致上穿环钢筋与基础环接触而被疲劳剪断,风机筒身亦因倾斜过大以致于无法正常运行。根据风机基础荷载,对最不利穿环钢筋单元进行了基于极端荷载和疲劳强度工况下的承载力验算,认为穿环钢筋的存在难以满足风机基础受剪承载力要求,建议设计中应采取相应措施予以加强。

All kinds of fatigue damages existing in wind turbine foundation with foundation by investigations video detection） and measurements （ including foundation pipe leveling, concrete strength pipe have been researched detection and bottom flange at home. The fatigue damage mechanism of wind turbine foundation applied foundation pipe is list as follows, which first appears cracks at prevailing wind direction; then the cracks extend to bottom flange and the concrete at prevailing wind direction is grinded to cavity by bottom flange; at last the wind turbine could not work because brittle fracture appears at bars thread foundation pipe in upper hole of foundation pipe and wind tower turbine inclines seriously. The bearing capacities of bar thread foundation at extreme and fatigue condition are calculated under performance load from wind turbine supplier. The calculation shows that the strength of bar thread foundation cannot satisfy the shear strength of wind turbine foundation and strengthening measures should be taken in the design.