﻿ 破冰船舵设备载荷计算方法
 舰船科学技术  2019, Vol. 41 Issue (1): 39-43 PDF

1. 齐鲁工业大学（山东省科学院），山东 济南 250014;
2. 山东省科学院海洋仪器仪表研究所，山东 青岛 266101;
3. 山东省海洋仪器仪表科技中心，山东 青岛 266101

WANG Yan-long1,2, YANG Feng-li3, LI Jin-hua1,2
1. Qilu University of Technology (Shandong Academy of Science), Ji’nan 250014, China;
2. Institute of Oceanographic Instrumentation, Shandong Academy of Science, Qingdao 266101, China;
3. Shandong Technological Center of Oceanographic Instrumentation, Qingdao 266101, China
Abstract: With the global warming and glaciers melting, polar navigation not only bring great facility to exploitation of energy in artic region, but also greatly reduce the distance between Europe and Asia. The safety of ship that sail in artic region become the most important consideration when design the ship. Based on the characteristics of polar ship, requirement to polar rudder system by regulations and calculation methods of loads, the paper give some research on rudder system under the ice layer with theory of ice/hydrodynamics. Compared with the structure reaction under the normal sea conditions, the reaction of rudder to the collision of ice belt is carried out by FEM method. The conclusion will provide some reference for design of polar rudder system.
Key words: polar     rudder system     loads calculation     structure check
0 引　言

1 冰区船舶舵系设备特点

2 冰区船舶舵设备载荷分析及计算方法

2.1 敞水海域正车航行转舵工况

 图 1 舵系外形图 Fig. 1 Plan of rudder system

 $F = 132 \cdot \frac{1}{3}\left(\frac{{{b^2}}}{{{A_t}}}{\rm{ + 2}}\right) \cdot 1.1 \cdot AV_d^2\text{。}$ (1)

 ${M_b} = F\left[ {{l_2} + \frac{{{l_1}(2{C_1} + {C_2})}}{{3({C_1} + {C_2})}}} \right] \; {\rm{N}} \cdot {\rm{m}}\text{，}$ (2)

 ${P_1} = \frac{{{M_b}}}{{{l_3}}}\text{，}$ (3)

 ${P_2} = F + \frac{{{M_b}}}{{{l_3}}}\text{，}$ (4)

 $T = FR\text{。}$ (5)

2.2 冰区正车航行转舵工况

 $p = {c_d} \cdot {c_p} \cdot {c_a} \cdot {p_0}\text{，}$ (6)
 ${c_d} = \frac{{ak{\rm{ + b}}}}{{1000}}\text{，}$ (7)
 $k = \frac{{\sqrt {\Delta P} }}{{1000}}\text{。}$ (8)

 图 2 舵叶结构图 Fig. 2 Plan of rudder structure

 图 3 舵叶表面冰载荷分布图 Fig. 3 The ice loads around rudder surface
2.3 倒车切削冰脊工况

 图 4 舵系有限元模型 Fig. 4 The FEM modal of rudder

 ${\bar P_{ice}} = 0.668\ 54 \cdot {e^{(\frac{x}{{0.027}})}} + 0.331\ 47 \cdot {e^{(\frac{x}{{0.497}})}}\text{。}$ (9)

 ${F_{ice}} = \int {{P_{ice}}} \cdot \cos (n,z){\rm d}s\text{。}$ (10)

FSICR基于实船测量试验和数值模拟分析，给出了冰脊（堆积冰）与船体结构挤压作用下的冰载荷计算公式：

 ${F_{tr}} = 32 \cdot {v_s}^{0.66} \cdot {H_r}^{0.9} \cdot {A_t}^{0.74} = {P_{ice}} \cdot {A_t}^{0.74}\text{。}$ (11)

 图 5 不同加载速率及温度下层冰压缩强度（单位：MPa） Fig. 5 The compressive strength of ice under different loading rate and temperature

3 舵系表面载荷特性分析

 图 6 工况1舵系载荷分布 Fig. 6 The loads of rudder under NO.1 load case

 图 7 工况2舵系载荷分布 Fig. 7 The loads of rudder under NO.2 load case

 图 8 工况3舵系载荷分布 Fig. 8 The loads of rudder under NO.3 load case

 图 9 工况1舵叶合成应力云图 Fig. 9 The von stress of rudder under NO.1 load case

 图 10 工况2舵叶合成应力云图 Fig. 10 The von stress of rudder under NO.2 load case

 图 11 工况3舵叶合成应力云图 Fig. 11 The von stress of rudder under NO.3 load case

1）船舶在冰区航行时，其舵系表面应力远远大于在常规海域的载荷，为避免舵系设备过重，冰区航行船舶需考虑高强钢进行舵系设计。

2）冰区挤压作用下的舵叶表面，由于内部隔板与旁外板的刚度水平差异，使得其应力分布在下舵承和舵叶内部隔板处的应力大于其他区域，隔板与旁板连接处的结构过渡和应力集中应给予重视。

3）运用冰水动力学理论得出的倒车冰脊载荷工况，其应力分布大于按法规计算得出的冰带分布载荷，本文在计算冰脊挤压载荷时采用层冰挤压强度代替冰脊的物理属性，结果相对保守，在舵系设备实际设计过程中，应结合实际航线的冰区情况考虑该方面的影响。

4 结　语

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