Institute of Fundamental Technological Research

This paper focuses on mitigation of dynamic loading induced on off-shore towers by drifting ice. Conical structures attached to off-shore towers at water level are widely used to reduce static and dynamic ice actions. The level of remaining forces is enough to cause severe tower vibrations, therefore a need for an additional device to reduce the remaining actions is recognized. Present study introduces a new, compliant connection between the cone and the tower. Parameters of the connection are controlled semi-actively to optimize the effect. Numerical studies are made to roughly estimate the effectiveness of the new solution. First, contact problem of ice sheet and cone is simulated using simplified material model for ice. Then a numerical model of a wind turbine tower is constructed. Dynamic interaction between cone and tower is simulated and the new solution effectiveness is discussed.

Impact load mitigation, Semi-active control, Conical structures, Ice loading, Off-shore wind turbine, Structural dynamics