The Vibration Control Of Offshore Platform With Viscoelastic Dampers

An offshore platform is subjected to the action of environment loads such as the wind, wave, flow and ice etc.. these loads are long-term and consecutive, so an offshore platform exist more serious vibration during its serving life than other buildings in land. This paper studys offshore platforms vibration control with viscoelastic dampers and give the method that is to control the offshore platform vibration with viscoelastic dampers, based on the study of vibration control of offshore platforms in home and broad. The wave is subscribed by regular and stochastic wave theory. The wave force acting on the offshore platform is calculated by the Morison Equation. The performance of viscoelastic dampers is analyzed and the model of vicoelastic damper is builded. The parameters of viscoelastic damper is designed according to the environment. The offshore platform control system with viscoelastic dampers is studied based on modern control theory. The movement equation and state space equation of an offshore platform control system with viscoelastic dampers is builded. The pole location technique is proposed and the location of viscoelastic dampers is optimized. The pole location technique is contrasted to the viscoelastic dampers location method that dampers is located by mean square deviation of relative displacement between layers of offshore platforms. Considering the difference of time that the wave crest reaches the adjacent platforms, the adjacent offshore platform vibration control with viscoelastic dampers is studied as well. The results show it is effective to control the vibration of offshore platform with viscoelastic dampers.