Response of a Boat Landing System to the Accidental Collision by a Supply Boat

The impact response of a boat landing system to the accidental collision by a supply boat is investigated. The structure is modelled using pipe and stiffness elements and finite element method is used in the analysis. Impact force due to boat collision is determined using an earlier analytical model. Since the impact period is more than twice the smallest natural period of vibration of the boat landing system, it is seen that a statical analysis would have been sufficient to determine the deformation and the support reaction forces. Parametric studies are carried out to determine the influence of the mass and velocity of the supply vessel, stiffness of the fender system (torque rings and energy cells) and the impact duration on the reaction forces exerted on the offshore platform. It is observed that as the impact period is shortened, the dynamic magnification increases necessitating the requirement for a dynamic analysis.