Study On Influence Of Bow Shape To The Collision Between Ship And Ice

Every year Bohai Sea and Northern Yellow Sea in the winter appear a large number of ice, which is a serious threat to the safety of navigation and the safety of people’s lives. Ice causes serious damage to the marine shipping industry, fishery,oil mining industry and so on, which bring great loss to the people’s economy. Due to the ice of the Bohai Sea area is seasonal, and has strong randomness, so sailing ships in the region generally fail to take icebreaking device. So the study on icebreaking ability of different bow shapes has a certain practical significance for the ships sailing in the area.This paper studies the simulation of collision scenarios between the different bow shapes and ice by using LS-DYNA, a finite element software, and uses the Lagrange scheme central difference algorithm to calculate the problem of large deformation of ship-ice collision to explore the influence of different bow shapes to the process of ship-ice collision.Based on the isotropic elastic failure ice model, the pressure-area curve calculated by the ice material model in the impact process is compared with the ISO-ALIE recommended curve and the test data, which effectively validates the feasibility of ice model and LS-DYNA software analysis method. The material model can be applied to the numerical simulation of ship-ice collision. Ignoring the bow structure damage deformation and researching icebreaking ability of different bow shapes, this paper studies the simulation of collision between the different bow shapes and ice by regarding initial velocity of the bow and ice thickness as variables respectively, which is achieved by using LS-DYNA, a nonlinear finite element software. Through analyzing and comparing icebreaking distance, ice loads and energy variation of bows and deformation energy of ice, the results show that the icebreaking distance, ice loads and energy variation of bows in different shapes have significant differences under same working conditions. Finally, considering the damage deformation of bow and building a simplified bulbous bow model of13000 t bulk carrier, dynamic response of ship-ice collision is studied respectively from the collision damage deformation, energy change, collision force and theicebreaking distance by regarding thickness of outer plate, thickness of strong structure and quality of the bow as variables, which can qualitatively obtain the influence of the above factors on the ship-ice collision.The research has a certain guiding significance for the ships sailing in seasonal ice region and provides reference for the improvement of anti-ice load design.