﻿ 基于有限元分析的船舶制造结构设计仿真
 舰船科学技术  2023, Vol. 45 Issue (24): 57-60    DOI: 10.3404/j.issn.1672-7649.2023.24.010 PDF

1. 兰州交通大学，甘肃 兰州 730000;
2. 兰州资源环境职业技术大学，甘肃 兰州 730000

Design simulation of ship manufacturing structure based on finite element analysis
ZHAO Xiao-fang1,2
1. Lanzhou Jiaotong University, Lanzhou 730000, China;
2. Lanzhou Resources and Environment VOC-TECH University, Lanzhou 730000, China
Abstract: The structural design of a ship directly affects its performance indicators such as strength, stiffness, and stability. Traditional ship structural design methods mainly rely on experience and experimentation, which have problems such as long design cycles, high costs, and low efficiency. However, ship structural design methods based on finite element analysis can achieve automation and optimization of structural design through numerical simulation and optimization algorithms, improving design efficiency and quality. The article analyzes the ultimate strength theory and fatigue strength theory of ship structures, and conducts design simulation of ship manufacturing structures based on finite element software.
Key words: finite element     manufacturing structure     ultimate strength     fatigue     simulation
0 引　言

1 船舶制造结构设计的极限强度和疲劳特性研究 1.1 船体结构的极限强度理论分析

 图 1 高强度钢Q420的结构应力-应变关系 Fig. 1 Structural stress-strain relationship of high-strength steel Q420

 ${\sigma _x} = \left\{ {\begin{array}{*{20}{l}} {{\varepsilon _x} \times E}\text{，} {{\varepsilon _x} \leqslant {\varepsilon _y}} \text{，} \\ {{\sigma _y}}\text{，} {{\varepsilon _x} > {\varepsilon _y}} \text{。} \end{array}} \right.$

1）弹性阶段

 $\sigma = \left\{ {\begin{array}{*{20}{l}} {E{\varepsilon _x}}\text{，} {{\sigma _{}} \leqslant {\sigma _y}}\text{，} \\ {E{\varepsilon _x}\frac{{{A_r}}}{A}}\text{，}{\rm{else}} \text{。} \end{array}} \right.$

2）塑性阶段

 $w = \frac{{2a}}{{\text{π}} }\sqrt {{\varepsilon _y} - {\varepsilon _x}} \text{。}$

 ${\sigma _n} = \left\{ {\begin{array}{*{20}{l}} {\dfrac{{{M_p} - (1/8)q{a^2}}}{{{A_r}{w_T}}}} \text{，} {{\sigma _x} \leqslant {\sigma _y}} \text{，} \\ {\dfrac{{{M_p} - (1/8)q{a^2}}}{{{A_r}{w_T}}}} \text{，} {\rm{else}} \text{。} \end{array}} \right.$

3）扩展失效阶段

1.2 船舶结构的疲劳特性理论分析

1）裂纹扩展理论

 图 2 典型的筋板结构裂纹扩展示意图 Fig. 2 Schematic diagram of crack propagation in a typical rib plate structure

 ${\sigma _{ij}} = \frac{{{K_c} \cdot {K_1}}}{{\sqrt {2{\text{π}} r} }}{\phi _i}(\theta ) \text{。}$

 ${K_c} = \sigma \sqrt {{\text{π}} a} f(\frac{a}{W}, \cdots ) 。$

 $\begin{gathered} {\sigma _p} = \frac{1}{{2{\text{π}} }}{\left( {\frac{{{K_1}}}{{{\sigma _w}}}} \right)^2}\text{，} \\ {\delta _p} = \frac{1}{{2{\text{π}} }}{\left( {\frac{{{K_1}}}{{{\sigma _{\text{w}}}}}} \right)^2}{(1 - 2v)^2}\text{。} \\ \end{gathered}$

2）线性累积损伤理论

 ${D_i} = \frac{{{n_i}}}{{{N_i}}} \text{。}$

 $D = \sum\limits_{i = 1}^k {} \frac{{{n_i}}}{{{N_i}}} \text{。}$

 图 3 船舶结构高强钢Q420的材料S-N曲线 Fig. 3 Material S-N curve of high strength steel Q420for ship structures

2 基于有限元分析的船舶制造结构设计仿真

 图 4 有限元分析的基本流程 Fig. 4 The basic process of finite element analysis

1）几何建模

2）网格划分和材料建模

 图 5 船舶壳体有限元模型 Fig. 5 Finite element model of ship shell

3）载荷和边界条件

 $S\left( w \right) = \frac{{1.25{w_p}^4{H_s}{e^{1.25\frac{{{w_p}}}{w}}}}}{{4{w^5}}} \text{。}$

4）求解和评估

 图 6 不同工况下的船舶壳体结构损伤值 Fig. 6 Damage values of ship shell structures under different working conditions
3 结　语

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