基礎構造が異なる海上風力発電施設の波浪及び風に対する振動特性の解析

抄録

The construction of the wind farms in Japan has been planed nearshore such as oncaissons of a harbor. However several offshore wind farms have already been constructed in European countries.Since oscillations of the offshore wind turbine have potential of fatigue damage to the wind turbine structures, itis necessary to appropriately select from various sub sea base structures such as a mono-pile, a caisson and a jacket, corresponding to the soil condition of the foundations, water depth and environmental condition so on. Here weconducted the time domain structural analyses for a blades-nacelle-tower-foundation system subjected to fluctuatingwind and wave loadings in order to examine the effect of the sub sea foundation to the vibration characteristics ofthe system. The foundation structures having the three (high, medium, low) level of flexural rigidity were analyzed. Asfor wind force calculations, two kinds of offshore wind spectra were used, while wave forces were obtained through Morison equation with the associated area and volume of a sub sea base structure. The paper describes theresults of dynamic analyses for the structural system in the operational and extreme conditions along with the naturalperiods of the structural system.