해저지반의 세굴현상을 고려한 해상풍력터빈의 하부구조물 변화에 따른 동적응답현상 연구

Abstract

In this work, I investigate the dynamic characteristics of the offshore wind turbine structures taking into account scour effect. Three substructure types which are the monopile, tripod and jacket are designed for the different water depth with the 5MW baseline model. Using the modified p-y curve by the soil erosion on the seabed, the dynamic responses of the each substructure model are investigated. From the modal analysis, the reduction rate of 1st tower natural frequency at the monopile type is much higher than that of other two types. And the resonance problem with blade rotating frequency can be appeared by the GL guideline. From the load analysis, the monopile shows that the results at typical load sensors are increased by the scour effect. Tripod and Jacket types indicate that the loads at the nacelle and tower have almost no variation, but the loads are increased a little by the scour effect in the substructure. Therefore, it is considered that the monopile structure is really vulnerable to the scour effect. But the tripod and jacket structures are relatively safe to this effect.