Numerical Simulation And Experimental Study On Ship Collision Mechanism

With the development of shipping and transportation industry, quantity, tonnage and speed of ships increase rapidly, and the route becomes crowded, so collision accidents between ships occur unceasingly. When the ship collision happens in the sea or inland river, it always causes disasters, such as casualties, ship sinking, structure damage and environmental pollution. Therefore, it has crucial significance to study the mechanism of ship collisions and performance of damaged ship whether in the view of safety and economy or environment protection.To study the influence of water on collisions, numerical and experimental methods are used to establish two collision models with and without water in this paper. The peak values of impact forces of these two collision models are compared, and the influence of water on collision is studied.The major work of this paper is listed as follows:1) A simple collision model used to simulate the process that striking body moves toward and collides with a fixed obstacle is built using FEM. Impact forces of this model are calculated in the case of with water that using solid-fluid coupling method and without water respectively. The peak values of impact forces of collision models with water and without water are compared. It is shown that the peak values of impact forces in the case of without water are greater than that with water and that collision motion is impeded by the damping effect of water.2) A reasonable and reliable collision test system used to study the influence of water on collisions is put forward. A woody striking ship with a steel striking plate set at the bow is pulled by wire rope to move forward and collide with a pressure transducer fixed on the wall of the tank. Hundreds of collision tests are carried out with water and without water respectively, and Impact forces and velocities are recorded. During collision without water, the ship is placed on a track of angle bar. From the experimental results, it is also concluded that the peak values of impact forces of model without water are greater than that with water. It is proved that collision motion is impeded by the damping effect of water, while part of the initial kinetic energy of the ship is absorbed by water, then impact force decreases.