Author(s): Junji Sawamura
Linked Author(s): Junji Sawamura
Keywords: No Keywords
Abstract: This paper develops the 3D numerical simulation to calculate the ice force induced by the ice bending failure and the submerging of the broken ice pieces when a ship advances into level ice. A breaking force and a friction force between a ship and a level ice are calculated at the contact surface. An ice breaking force is induced by a bending failure of a floating ice plate. The bending behavior of the ice plate is simulated by FE fluid-structural interaction. A rotating and sliding motion of broken ice pieces after the bending failure are described by 6DOF rigid body simulation. Broken ice pieces and a ship are assumed to be rigid bodies. The contact points between ship hull and broken ice is calculated by sphere contact detection algorithm. The contact response between a broken ice piece and a ship hull is calculated by the theory based on the impulse force. The contact force and the friction force are assumed at the contact surface between a broken ice and a ship hull. The buoyancy force and the drag force are considered as the hydrodynamic force for the broken ice pieces. Numerical simulation of 2D model is compared with the experimental data in Valanto (1992). Numerical results of the ice force and the ice breaking length induced by the ice bending failure and the rotating of the broken ice pieces agrees with the experimental one. 3D simulations calculate the ice channel with zigzag ice edges and the ice force induced by the bending failure of a 3D wedge-shaped ice plate and the motions of the 3D semielliptical broken ice. The numerical results of the 3D model are much different from ones of the 2D model. The motion of the broken ice is varied with a 3D ship hull shape. In 3D simulations, a rotating and sliding force becomes relative smaller than one of the bending failure. The distribution of the ice force in the ice breaking phase and the submerging phase depends on the ice thickness.
Year: 2012