﻿ 极地船冰载荷简化计算方法研究
 舰船科学技术  2019, Vol. 41 Issue (10): 27-31 PDF

1. 中国人民解放军 91404部队，河北 秦皇岛 066000;
2. 哈尔滨工程大学 船舶工程学院，黑龙江 哈尔滨 150001

A simplified method for calculating the ice load of polar ships
Liu Dong1, Yang Zheng2, Li Hui2
1. No. 91404 Unit of PLA, Qinhuangdao 066000, China;
2. College of Shipbuilding Engineering, Harbin Engineering University, Harbin 150001, China
Abstract: The interaction between ship and seawater is a complex dynamic process, the finite element numerical software LS-DYNA is used to simulate the continuous icebreaking of a polar ship. Based on the consistency of the data from ice tank test and the numerical results of this paper, the accuracy of the ice-water coupling algorithm is validated. The quasi-static analysis method of ice load is proposed by. The direct calculation result of finite element is compared with the normative design load, the dynamic factor is introduced, and it is applied to the simplified simulation method of ice load calculation for collision ice breaking capacity. It is of guiding significance to the numerical simulation of the collision.
Key words: ice load     fluid-structure interaction     dynamic factor     simplified simulation
0 引　言

1 数值模拟 1.1 碰撞方程的建立和求解

 ${ M}{a'_{n + 1}} + { C}{v'_{n + 1}} + { K}{d'_{n + 1}} = { F}_{n + 1}^{ext}{\text{。}}$ (1)

 ${ M}{a'_{n + 1}} = F_{n + 1}^{ext} - F_{n + 1}^{\operatorname{int} }{\text{，}}$ (2)
 ${a_n} = {{ M}^{ - 1}}(F_{n + 1}^{ext} - F_{n + 1}^{\operatorname{int} }){\text{。}}$ (3)

${ M}$ 为一对角阵，则线性方程组为一系列关于各自由度的独立的一元一次方程，从而求得加速度：

 ${a_{ni}} = { M}_i^{ - 1}(F_{n + 1}^{ext} - F_{n + 1}^{\operatorname{int} }){\text{，}}$ (4)

 ${v_{n + {1 / 2}}} = {v_{n - {1 / 2}}} + {a_n}(\Delta {t_{n + {1 / 2}}} + \Delta {t_{n - {1 / 2}}})/2{\text{，}}$ (5)
 ${d_{n + 1}} = {d_n} + {v_{n + {1 / 2}}}\Delta {t_{n + {1 / 2}}}{\text{。}}$ (6)

 $\Delta t < \frac{{\Delta l}}{{v + x}}{\text{，}}$ (7)

 $\Delta t < \frac{{\Delta x}}{{Q + \sqrt {{Q^2} + {v^2}} }}{\text{。}}$ (8)

1.2 模型建立及工况设置

 图 1 船冰碰撞模型图 Fig. 1 Model of ship-ice collision

 图 2 各工况下冰载荷数值计算结果 Fig. 2 Numerical results of ice loads (a. Mode 1; b. Mode 2; c. Mode 3; d. Mode 4; e. Mode 5; f. Mode 6)
2 冰载荷模型试验 2.1 试验模型

 图 3 试验模型 Fig. 3 Test model （a. Bow; b. Stern）
2.2 数值计算结果与试验结果对比

3 直接计算值与规范值对比

 图 5 等效冰载荷脉冲曲线 Fig. 5 Pulse curve of equivalent ice load

 图 6 等效冰载荷作用下结构应力云图 Fig. 6 Stress fringe of bow structure under equivalent ice load
4 冰载荷简化模拟方法

5 结　语

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