Simulation of Ice-Sloping Structure Interactions With Peridynamic Method

Lu, Wei (Harbin Engineering University) | Wang, Qing (Harbin Engineering University) | Jia, Bin (Harbin Engineering University) | Shi, Li (Harbin Engineering University)

OnePetro 

ABSTRACT

In this paper, a nonlocal meshfree method, peridynamic theory is utilized to simulate the process of the interaction between level ice and a wide inclined structure. Since in peridynamic theory, the integration in the equation of motion is applied to calculate the force acting on the particles of the body instead of traditional differentiation, it has a huge advantage when handling spontaneously forming discontinuous issues such as the propagation of cracks. During the process of the interaction, with high initial velocity of the level ice, the ice behaves as a linear elastic material with a brittle mode of failure. To testify the accuracy of implementing peridynamic method on the ice-structure interaction, the result of the simulation in terms of ice force has been compared with the analytical formula, showing high agreement. Finally, for further study, several parameters that influence the fracture radius of the level ice had been discussed in detail.

INTRODUCTION

Currently, with the acceleration of polar ice melting resulting from the global warming, the opening of the Arctic Passage becomes possible. Therefore, the polar engineering and technology which contributes to icebreaking and the exploration of polar resource appeal lot scientists to study. To analyze the interactions between ice and marine structures, numbers of experiments and analytical solutions have been proposed in the past days. Based on the beam bending theory, Croasdale (1980) introduced a basic two-dimensional model for ice action on a slope structure, in which the ice is depicted as an elastic beam. This simple 2D analysis for ice breaking and ride-up on a sloping structure has been improved to be a full 3D analysis model by Croasdale and Cammaert (1994). To testify the applicability of Frderking-Timco theory, Li and Riska (2001) performed the experiments of the level ice interacted with 45°, 60°, 75° inclined walls under shallow water. With development of computational technology in recent years, the numerical simulation plays a vital role in the analysis of ice-structure interactions, due to its accuracy and low-cost advantages. A two dimensional discrete element method was implemented by Paavilainen et al. 2006 to study the ice pile-up process against an inclined plate. In this model, the contact forces between particles were calculated with an elastic-viscous-plastic material model combined with an incremental Mohr-Coulomb tangential force model. Compared with the experiment, it appeared that in the simulations the rubble piles were more loosely packed, resulting from the edge crushing. The ice forces obtained from the simulation were consistent with the results from analytical methods. Based on the cohesive zone theory, the cohesive element-based approach was utilized by Lu et al. (2012) to simulate the ice-sloping interactions. A random ice field and bulk energy dissipation considerations were introduced to alleviate the mesh dependency issue.