尺度效应对全附体潜艇阻力数值计算结果的影响

  目的  随着各国对北极地理和气候环境研究的深入，越来越深刻认识到潜艇在北极所能发挥的政治和军事价值。研究潜艇破冰上浮过程及冰载荷的动态特性，可为潜艇壳体的设计和破冰厚度的选择提供支撑。  方法  基于近场动力学方法建立潜艇破冰上浮过程计算模型。首先，详细介绍近场动力学方法用于捕捉物体断裂问题的理论基础，分析该方法用于海冰材料模拟的可行性。然后，为反映潜艇破冰上浮真实的物理过程，基于接触检测理论，建立海冰粒子与潜艇表面的接触区域识别算法，给出计算接触载荷方法。
最后，将近场动力学方法与接触区域识别算法结合在一起，开发潜艇破冰上浮计算程序，以跟踪每一个时刻的破冰状态，计算海冰对潜艇壳体的作用力。并以美国DARPA潜艇模型SUBOFF为计算对象，开展潜艇破冰上浮过程数值模拟。  结果  计算结果表明：在用所提方法模拟的潜艇上浮破冰过程中，海冰的动态断裂过程与观察到的美国核潜艇的破冰上浮结果基本一致，冰载荷的动态变化与实际情况相符合。  结论  该方法能为潜艇与冰的相互作用研究提供思路，所得结果可为极地潜艇壳体结构的优化设计提供支撑。

Discrete element analysis of ice loads on ships and structures

  Objectives  With deepening research on the geographical and climatic environment of the Arctic, the political and military value of submarines in the region has been well recognized. Although the thick ice in the Arctic provides natural protection for submarines, it also poses a risk to submarines during the ice surfacing process. A method for accurately predicting the ice surfacing process and transient ice loads can be the most important issue in the design of submarine shells and choice of ice thickness.  Methods  In this paper, a numerical method for dealing with the submarine and ice contact problem is developed. First, the peridynamic theory on the capture of material fractures is briefly introduced and the feasibility of peridynamics in modeling the ice failure problem is discussed.
To reflect the physical reality of submarine-ice interaction, a contact detection algorithm is established to prevent the interpenetration of the submarine surface and ice material particles, and a method for calculating the contact load is introduced. Finally, based on peridynamics and the contact detection algorithm, a numerical program for predicting submarine-ice interaction is compiled. Using the DARPA SUBOFF submarine model, the ice surfacing process of a submarine is simulated.  Results  The results show that this method can vividly capture the ice failure process, which corresponds to observations of the ice surfacing process of American nuclear submarines, and the dynamic ice load can be calculated over time.  Conclusions  This method provides new concepts in the study of submarine-ice interaction, and its results support the optimal shell structure design of arctic submarines.