船-冰作用中海冰典型破坏模式的离散元数值模拟

Discrete element numerical simulation of typical failure modes of sea ice under ship-ice interaction

在破冰船破冰过程中,冰排主要表现为挤压与弯曲两种破坏模式。本文基于黏结离散单元法对船-冰作用中的这两种典型破坏模式进行数值模拟。海冰离散元数值试样采用随机排布方式生成,采用单轴压缩试验与三点弯曲试验相结合的方式标定模型中的细观参数。将船-冰碰撞中的挤压和弯曲作用方式简化为直立或倾斜平板与海冰的作用模式,构建挤压与弯曲破坏的海冰离散元数值试样,分析了挤压破坏模式中不同加载方位以及冰厚和加载速率对破坏模式的影响,以及弯曲破坏模式中不同冰排夹角以及冰厚和加载速率对破坏模式的影响。计算结果表明,离散元海冰数值模型可以很好地对冰排挤压与弯曲破坏现象进行模拟,可揭示冰排在不同破坏模式下的破坏机理。

In the process of breaking the ice by an icebreaker,the ice raft mainly exhibits two failure modes:crushing failure and bending failure.In this paper,the two typical failure modes in ship-ice interaction are simulated numerically based on the bonding discrete element method.The discrete element numerical samples of sea ice were generated by random arrangement,and the mesoscopic parameters in the model were calibrated by the combination of uniaxial compression test and three-point bending test.The crushing and bending interaction mode in the ship-ice collision is simplified to the interaction mode between erect,inclined plate and sea ice.The discrete element numerical sample of sea ice in crushing failure and bending failure mode is constructed.The influence of different loading direction,ice thickness,loading rate on failure mode in crushing failure mode are analyzed,and the influence of different ice raft angle,ice thickness,loading rate on failure mode in bending failure mode.The results show that the discrete element numerical model of sea ice can be used to simulate the extrusion and bending failure of ice raft well,and the failure mechanism of ice raft under different failure modes can be revealed.