風力発電機用タワーのボルト締結の設計方法

抄録

It is important to assess both ultimate strength and fatigue strength of flange for design of the wind turbine tower. This paper introduce current mainstream method for evaluating both assessments. For ultimate strength analysis, assume several destructive modes of the flange and set the weakest mode as ultimate proof stress and evaluate its strength. Petersen and Seidel proposed some failure modes and Petersen method is used in Japan as a design guideline. For fatigue analysis, there are methods by which the relationship of the variation of the bolt stress with respect to the change of the external force of the tower shell is made into a function and a method of solving the balance of the moment in the thickness direction of the tower flange. In Japan, Shumidt/Neuper method belongs to the former as a guideline is used. Also, this paper introduces current approach improving tower flange ultimate strength. Action point correction factor can find the equivalent flange reaction force action point when the flange undergoes elastic deformation. The factor can evaluate ultimate strength accurately of wider flange which deform in larger external load.