1987

Riska, Kaj

The mechanics of the interaction occurring when a ship rams a massive ice floe is analyzed.A calculation procedure to determine the ice load and the ensuing ship response is developed.The experimental values from full scale and model scale ramming trials are compared with the calculated values.The ice displacement occurring due to the ship bow penetrating into the ice floe is divided into two components.One component correspond to the crushing penetration into ice and the other is associated with the elastic deformation of ice.A formulation of these two components based on measurements and calculations is developed.The ship motions and ship hull vertical deformation are analyzed treating the ship hull as a Timoshenko beam.The water surrounding the ship hull is accounted for using the strip theory.In the calculation procedure the ship motions and ice displacement are combined by a kinematic condition.The procedure developed is applied to three ramming cases.The ramming of M.V.Arctic is studied both in model scale and full scale.The repeated ramming of Canmar Kigoriak on existing bow imprints is also studied. This study on the mechanics of ramming interaction does not include all aspects needed for ship design.The aim is to develop a model to determine ice load in ramming based on ice mechanics and ship particulars.