Dynamic Response Of Ship Plates Impacted By Ice Floes

With the development of the Arctic waterway and exploration of the polar resources,more and more ships navigate in Arctic waters.Due to the global warming caused by the large emissions of greenhouse gases,ice is melting increasingly resulting in large number of small icebergs and ice floes distributing in Arctic waters.This phenomenon brings great difficulties and many threats to the ship’s navigational performance,and the structural strength of the polar ships under the ice floes impact becomes the key issue to be addressed.In this paper,the experimental and numerical simulation methods are used to study the dynamic responses of ship plates and stiffened plates under the ice floes impact.The impact parameters and geometric parameters of stiffened plate are discussed in the collision process.The main contents are listed as follows:The experiments on scaled ship plates impacted by ice were conducted based on the self-designed horizontal impact machine.The preparations for the experiment include the experimental devices,data acquisition instruments,and preparation of artificial freshwater ice.Before the main experiments,tensile tests were carried out for the test plates,and the uniaxial compression tests were carried out for ice.The impact velocity,rebound velocity,acceleration of the ice,and deformation of the test plates were obtained.Then,the ship plate-ice collision model and stiffened plate-ice collision model are established by using the nonlinear finite element software ANSYS/LS-DYNA,and the dynamic responses of ship plates were studied.The numerical results agreed well with the experimental results,which verified the reliability of the numerical simulation method.Furthermore,the effects of collision parameters including the ice mass,impact velocity,the thickness of ice,the angle of ice wedge and ship plate thickness,on the dynamic behavior of plates were numerically investigated.The dynamic responses of ship plates,such as the deformation of plate,deformation of ice floes,impact force of collision,internal energy of the plate,were studied under above conditions.Finally,the parameters of stiffened plate like the number of stiffeners,type of stiffened plate,width of stiffeners,and thickness of stiffeners were investigated of.The deformation of stiffened plate,the damage of ice,the collision force,and the internal energy of stiffened plate were discussed under the circumstances.This paper combines the experimental and numerical simulation methods to reveal the dynamic responses of ship plate and stiffened plate under ice floe impacts,which may provide suggestions to the design of ship structures against the ice impact.