﻿ 船体结构数值模型简化方法研究
 舰船科学技术  2020, Vol. 42 Issue (10): 1-5    DOI: 10.3404/j.issn.1672-7649.2020.10.001 PDF

Research on simplified method of numerical model of hull sructure
FENG Liang, LI Dong-yang, SHI Hong-da, HU Luo-cun
College of Engineering, Ocean University of China, Qingdao 266100, China
Abstract: The model test of hull longitudinal strength is very difficult because of huge and complex hull structure. Therefore, simplified method of hull girder model is of great significance to the study of hull longitudinal strength. Aiming at the failure mode of hull girder, a simplified method of hull girder model is proposed in this paper. According to the simplified method, a simplified model of mid-hull section under hogging and sagging condition is established. The ultimate bending moment of the complete and simplified model is compared to verify the feasibility of this method for analyzing the ultimate bending moment of hull girder. The method provides a reference for the research of ultimate strength and residual strength.
Key words: ultimate bending moment     stiffened plates     buckling     arc-length method     equivalent simplification
0 引　言

1 船体梁总纵强度模型简化方法

 图 1 加筋板简化示意图 Fig. 1 Simplification of stiffened panel
1.1 船体受压加筋板等效板厚计算

 ${\sigma _{u1}} = {\sigma _{u2}}\text{。}$ (1)

1.2 船体受拉加筋板等效板厚计算

 ${t_{\text{受拉等效}}} = \frac{{bt + n({h_w}{t_w} + {b_f}{t_f})}}{b}\text{。}$ (2)

2 散货船中舱段模型简化

 图 2 散货船各加筋板编号 Fig. 2 Numbers of bulk carrier’s stiffened panels

 图 3 HT32钢材应力应变关系 Fig. 3 HT32 steel’s relationship of stress and strain
2.1 船中舱段受压加筋板等效厚度计算

 $\frac{{{\sigma _u}}}{{{\sigma _y}}} = \frac{{2.25}}{\beta } - \frac{{1.25}}{{{\beta ^2}}}\text{，}$ (3)
 $\beta = \frac{b}{t}\sqrt {\frac{{{\sigma _y}}}{E}}\text{。}$ (4)

 图 4 ①号加筋板后屈曲失效云图 Fig. 4 Post buckling failure of ① stiffened panel

 图 5 ①号等效板后屈曲失效云图 Fig. 5 Post buckling failure of ① equivalent panel

 图 6 ①号加筋板及等效板应力-位移曲线 Fig. 6 Stress-strain curves of ① stiffened panel and its equivalent panel
2.2 船中舱段受拉加筋板等效厚度计算

2.3 散货船舱段简化模型

 图 7 简化三维几何模型 Fig. 7 Simplified geometric 3D model

 图 8 简化模型中垂弯曲失效云图 Fig. 8 Failure mode of simplified model under vertical sagging bend
3 简化方法可行性验证

3.1 中垂工况极限弯矩

 图 9 完整模型中垂弯曲失效云图 Fig. 9 Failure mode of intact model under vertical sagging bend

 图 10 中垂工况弯矩-转角曲线 Fig. 10 Moment-angle curves of sagging bending
3.2 中拱工况极限弯矩

 图 11 简化模型中拱弯曲失效云图 Fig. 11 Failure mode of simplified model under vertical hogging bend

 图 12 完整模型中拱弯曲失效云图 Fig. 12 Failure mode of intact model under vertical hogging bend

 图 13 中拱工况弯矩-转角曲线 Fig. 13 Moment-angle curves of hogging bending
3.3 可行性验证

4 结　语

1）根据本文提出的加筋板简化方法，将受压加筋板简化为等效厚度的板格，考虑了加筋板和等效板的受压极限强度相等，可为计算加筋板的极限强度及剩余强度提供简化的分析模型。

2）船体舱段完整模型及简化模型的极限弯矩误差在5%以内，且考虑了模型的失效一致性，可知本文提出的总纵强度完整模型简化方法具有一定的可行性，对于研究船体极限强度及剩余强度具有参考价值。

3）本文的加筋板及船体梁模型简化方法仅考虑极限强度值和失效模式的一致性，但应力及弯矩曲线没有达到重合，要得到更合理的简化模型需要进一步深入研究。

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