Simulation Of Ice Load On Ocean Structures Based On Cohesive Element Method

More and more polar activities have to face severe challenges due to the Arctic cold climate.Due to the existence of a large number of sea ice in the polar region,polar marine structures will collide with sea ice when they are working at sea,and the ice load generated in the collision will pose a serious threat to the safety of structures.As a common form of sea ice in polar regions,the research on ice load caused by collision between ice layer and structure is an important content of structural safety.Based on the cohesive element method,a reasonable ice layer model is established to analyze the ice layer structure collision process and explore the ice load law of structures under different ice conditions,the details are summarized as follows:The formula of cohesive zone length is modified to make it suitable for ice material model.Based on a large amount of numerical simulation data,this paper found that the length of the cohesive zone varies with the thickness has a limit,and based on this,a correction equation for calculating the length of the cohesive zone is proposed.The effectiveness and accuracy of the modified method are verified by different numerical models and comparison with previous research results,which provides a reference for reasonable mesh generation.According to the ice material model,a reasonable relationship between the length of cohesive zone and the size of cohesive element is established.Through the simulation study of the opening failure of the double cantilever beam,it is found that there are at least four cohesion units within the length of a cohesion zone in order to ensure the calculation accuracy.Then,based on the existing research results,a three-point bending test was carried out for numerical simulation,and good simulation results were obtained.Finally,the ice breaking ship is simulated in level ice.Based on the cohesive element method,various ice loads of different icebreakers under certain ice conditions are simulated,and the validity of the numerical model is verified by comparing the simulated data and the experimental data.The effect of the fluid on the ice load is subsequently studied.Further research found that the total ice load is more sensitive to speed and ice thickness,while the ice breaking load is more sensitive to ice thickness.