Dynamic Characteristics of Irregular Ice Floes Based on Polyhedral Discrete Element Method  

基于多面体离散元方法的非规则海冰动力特性分析

作　　者：LI Ji WANG Si-qiang LIU Lu JI Shun-ying 李继;王嗣强;刘璐;季顺迎(大连理工大学工业装备结构分析优化及CAE软件全国重点实验室,辽宁大连116024)

机构地区：[1]State Key Laboratory of Structural Analysis,Optimization and CAE Software for Industrial Equipment,Dalian University of Technology,Dalian 116024,China

出　　处：《船舶力学》2024年第12期1849-1863,共15页Journal of Ship Mechanics

基　　金：国家自然科学基金资助项目(52192693;52192690;42176241;12102083);工业和信息化部专项(2021-342)。

摘　　要：In polar regions, floating ice exhibits distinct characteristics across a range of spatial scales. It is well recognized that the irregular geometry of these ice formations markedly influences their dynamic behavior. This study introduces a polyhedral Discrete Element Method (DEM) tailored for polar ice, incorporating the Gilbert-Johnson-Keerthi (GJK) and Expanding Polytope Algorithm (EPA) for contact detection. This approach facilitates the simulation of the drift and collision processes of floating ice, effectively capturing its freezing and fragmentation. Subsequently, the stability and reli ability of this model are validated by uniaxial compression on level ice fields, focusing specifically on the influence of compression strength on deformation resistance. Additionally, clusters of ice floes nav igating through narrow channels are simulated. These studies have qualitatively assessed the effects of Floe Size Distribution (FSD), initial concentration, and circularity on their flow dynamics. The higher power-law exponent values in the FSD, increased circularity, and decreased concentration are each as sociated with accelerated flow in ice floe fields. The simulation results distinctly demonstrate the con siderable impact of sea ice geometry on the movement of clusters, offering valuable insights into the complexities of polar ice dynamics.极地海冰在多种空间尺度上呈现出离散分布特征,本文基于Gilbert-Johnson-Keerthi(GJK)和Expanding Polytope Algorithm(EPA)接触算法发展一种用于极地海冰的离散元方法。该方法允许模拟浮冰的漂移和接触碰撞过程,并基于简化的刚体有限元方法表征海冰的冻结破坏。通过在平整冰场上进行单轴压缩模拟证实程序的稳定性,并研究压缩强度对浮冰场变形的影响。在此基础上,对穿越狭窄通道的冰块集合进行离散元模拟,研究浮冰尺度、初始密集度和圆形度对其流动特性的影响规律。结果表明,在幂律分布的浮冰尺度分布函数中增大幂指数、增加圆形度以及降低初始密集度都会导致浮冰场的流动速度加快。

关 键 词：discrete element method GJK-EPA algorithm sea ice dynamics floe geometry 

分 类 号：P731.15[天文地球—海洋科学]