Research On Impact Resistance Of Sandwich Plate Under Ice Collision Load

Nowadays,the exploitation of polar resources and the use of waterways have become the focus of research on polar ice.However,ice-snow covered area,its resource exploitation,scientific investigation,and utilization of waterways are inevitably required to be applied to ships sailing in the polar region.Due to the special environmental characteristics of the polar region,ships in polar ice areas are faced with many challenges,especially the unpredictable impact and destruction of large numbers of floating ice on ships.As a result,higher requirements are required on the crash worthiness of ships.The composite structure,especially the sandwich structure,is widely used in ship repairing,shipbuilding and other fields due to its high specific strength,high specific stiffness,heat insulation and sound insulation.It is of great practical significance to design and study the response and damage mechanism of the new ship structure under the action of ice collision load in order to enhance the crash worthiness design of ships in ice area.This paper mainly focuses on the I-type metal sandwich plate structure for ships and finite element simulation method is adopted to study the impact resistance of shipboard metal sandwich panels under ice impact loads.The main research content includes:(1)Based on the mechanical properties and constitutive models of sea ice in different regions,the ice constitutive model suitable for this study was proposed,and the accuracy of the ice material was verified by finite element software ANSYS/LS-DYNA.(2)Under various load conditions,such as different shapes of ice bumping different positions of the I-type sandwich structure at different impact speeds,the characteristics of the sandwich plate structure such as damage deformation,collision force and energy absorption are comparatively studied,and the ice collision load parameters are developed.Impact relations are established between ice impact loading and structural impact resistance.(3)Studies on I-type sandwich plate structure against ice collision performance research are carried out.First of all,under the principle of equal mass design,I-type metal-based sandwich plate structures with different thicknesses of upper and lower panels are designed.Through finite element simulation analysis technology,the response characteristics and energy absorption of sandwich plate structures under ice impact loading are studied.Through comparative analysis,The structural design of the sandwich plate structure with better structural impact resistance is preferred.On this basis,the influence of the mechanical properties of the sandwich core material on the ice-collision resistance of the structure was studied.Comparisons between collision force and energy absorption of the structure was focused on,and the relationship between the material parameters of the sandwich plate and the crash worthiness of the structure was established.(4)Welding is one of the most important methods for the processing and connection of metal-based sandwich structures,while low temperature has a significant effect on the mechanical properties of welds.Therefore,considering the low-temperature characteristics of the polar environment,the influence of low temperature on the bending strength of the sandwich plate weld seam and the impact toughness of the weld seam was analyzed,and the law between the temperature and the mechanical properties of the weld seam was established.(5)Based on the principle of equal weight,the outer deck of the side cabins in the traditional cabin segment is reinforced with a design based on the principle of equal weight,and a new sandwich-side reinforced structure is designed;under the impact of ice,the traditional side structure and the new type are compared by analyzing the damage deformation,the impact force and the energy absorption characteristics.The results verified the superiority of the new type of side sandwich reinforcement structure.