﻿ 砰击载荷作用下的双体船湿甲板综合优化
 舰船科学技术  2020, Vol. 42 Issue (2): 60-63 PDF

Comprehensive optimization of wet deck of catamaran under slamming load
LI Fei, JIANG Cai-xia, HU Jia-jun, GAO Yuan
China Ship Scientific Research Center, Wuxi 214082, China
Abstract: Because of its high speed and unique structure, the wet deck of catamaran hull is greatly affected by slamming load, and its structural safety is greatly threatened. The parameterized model of the wet deck structure of the target ship is established by using the finite element software Ansys, and the slamming load at the wet deck is analyzed and solved by using the CFD method. Taking Isight as the platform, integrating finite element software, taking the thickness of each position of wet deck, the size and quantity of truss and aggregate as design variables, structural stress as restraint condition, and structural weight of wet deck as objective function, the optimum design of wet deck of catamaran under slamming load is carried out. The calculation results show that the goal of uniform stress distribution and lightweight structure can be achieved at a lower cost by considering the optimization of structural layout.
Key words: catamaran     wet deck     structural optimization     stress reduction
0 引　言

1 湿甲板砰击载荷特性

 ${{P}} = {{{K}}_P}{V_r}^2,\;\;\;\;{\rm kPa}{\text{。}}$ (1)

 图 1 砰击载荷作用下双体船湿甲板应力云图 Fig. 1 Stress nephogram of wet deck of catamaran under slamming load
2 湿甲板结构综合优化 2.1 双体船湿甲板优化模型

 图 2 双体船湿甲板三维有限元模型 Fig. 2 Three-dimensional finite element model of wet deck of catamaran

 $\begin{split} &{{F}}\left( {{X}} \right) = {\rm{\rho }}\mathop \sum \nolimits_{i = 1}^n {t_i}{A_i} + \rho \mathop \sum \nolimits_{i = 1}^m \left( {{w_{i1}}{h_{i1}} + {w_{i2}}{h_{i2}}} \right){l_i}{\text{，}}\\ &{\rm{s}}.{\rm{t}}.{\rm{}}\;\;\;{g_i}\left( X \right) {\text{≤}} 0,\;\;\;{{i}} = 1,2,3, \ldots ,{{s}}{\text{。}} \end{split}$ (2)

2.2 优化结果分析

 图 3 双体船湿甲板优化历程图 Fig. 3 Optimized history diagram of wet deck of catamaran

 图 4 方案1湿甲板应力云图 Fig. 4 Stress nephogram of scheme 1 wet deck

 图 5 方案2湿甲板应力云图 Fig. 5 Stress nephogram of scheme 2 wet deck

1）方案1相较于初始方案，纵向桁材数目不变，桁材间纵骨个数减小为2个。为缓解横框处的应力集中，纵向桁材厚度、横框厚度增大。甲板厚度下降明显，设置于甲板上的1号骨材参数增大。对比应力云图可知，湿甲板最大应力由原来的312 MPa降低到201.3 MPa，使得结构的应力水平满足衡准要求，且优化后应力分布更为均匀；在应力降低到衡准要求的基础上，结构总重量减轻1 676.4 kg。

2）方案2相较于初始方案结构布局不变，通过改变构件尺寸，湿甲板最大应力降低为209.5 MPa，结构总重量减轻824 kg。

3）由方案1与方案2的优化结果对比可知，相对于尺寸的优化，结构形式的改变对结构应力分布以及结构轻量化的影响更加明显。

3 结　语

1）通过综合优化，在降低应力水平的同时使湿甲板结构的总重量减轻，对双体船的综合航行性能和经济性能的提升有很大帮助。

2）对比2种优化方案可知，相对于尺寸的优化，结构形式的改变对结构应力以及总重量的影响更加明显。为获取较大的优化空间，在优化设计中应关注结构布局的改进。

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