지지구조의 형식에 따른 해상풍력타워의 선박충돌거동비교

Abstract

The collision behaviors of the tripod and jacket structures, which are considered as support structures for offshore wind towers at theSouthwest sea of Korea, were compared by nonlinear dynamic analysis. These structures, designed for the 3 MW capacity of the wind towers,were modeled using shell elements with nonlinear behaviors, and the tower structure including the nacelle, was modeled by beam and masselements with elastic materials. The mass of the tripod structure was approximately 1.66 times that of the jacket structure. A barge andcommercial ship were modeled as the collision vessel. To consider the tidal conditions in the region, the collision levels were varied from –3.5m to 3.5 m of the mean sea level. In addition, the collision behaviors were evaluated as increasing the minimum collision energy at the collisionspeed (=2.6 m/s) of each vessel by four times, respectively. Accordingly, the plastic energy dissipation ratios of the vessel were increased asthe stiffness of collision region. The deformations in the wind tower occurred from vibration to collapse of conditions. The tripod structuredemonstrated more collision resistance than the jacket structure. This is considered to be due to the concentrated centralized rigidity andamount of steel utilized.