Ship Collision Analysis of Concrete Offshore Wind Turbine Structure Supported with Suction Pile

콘크리트 해상풍력 석션 지지구조물의 선박 충돌 해석

A concrete offshore wind turbine structure supported with suction pile for a weak soil foundation was proposed, and ship collision analysis was carried out to evaluate the concrete structure with a ship impact load. To take into account the effect of suction pile and soil on the structure, a lumped parameter model was used to calculate the soil stiffness matrix. As the first step, a linear analysis of the structure was carried out for a feasibility assessment of the designed structure. A 5 MW wind turbine and the environmental conditions of the southwest coast of Korea were applied. In a quasi-static analysis, maximum displacements and stresses did not exceed the allowable values from the offshore standard, and it was determined that no resonance occurred in a natural frequency analysis. For the ship collision evaluation, a nonlinear dynamic algorithm of ship collision was performed using a nonlinear concrete material model. A ship impact-load time history curve was applied, and maximum displacement and principal stresses were calculated. The principal stresses were not exceeded in the range of the concrete strength. Thus, damage to the concrete structure by ship collision was small, and it has enough stability to be applied on the southwest coast of Korea. Consequently, it is expected that the proposed structure can be a good solution for offshore wind farms.