Structural Dynamic Performance And Crashworthiness Of LNG Ships Interacting With Iceberg In Polar Region

With the increasing melting trend of sea ice in Arctic region,the north sailing route has come into reality.Ship-iceberg collision is currently one of the hot topics in the ship collision research area.This paper addresses the research in two main contents: using nonlinear finite element software LS_DYNA for the ship-iceberg collision simulation,and studying the influence factors like the collision speed,mass of iceberg,and local shape of sea ice,while the ideal elastic-plastic material model is used to simulate ice;putting forward the longitudinal framing and transverse framing ice-strengthening schemes,according to CCS standard,and comparing their advantages and disadvantages by the structural damage and steel costs.The collision speed,mass of iceberg,and local shape of sea ice are important factors for ship-iceberg collisions.Higher collision speed or greater mass of iceberg can cause more serious vessel injury,so the speed of ship navigating in polar region must be strictly controlled.The overall extrusion effect of bulbous bow is more obvious,when colliding with the iceberg with blunt local shape.The penetration effect is stronger when the local shape is sharp,which does more harm to the ship.It is found that the structure between the web frames of the transverse framing is too weak to resist ice impact,while the longitudinal framing shows better crashworthiness without obvious structural weakness;the longitudinal framing can convey more ice load to the inner plate through ice-strengthened longitudinals and web frames,but the increasing deformation of inner plate will not cause the failure of CCS;on the premise of improving the crashworthiness,longitudinal framing scheme has better economic benefit.