船舶结构冲击破坏一直都是学者们研究的重点，而碰撞破坏是船舶结构在生命周期内最有可能遭受的冲击破坏形式。因为船舶惯性质量大，在很低的速度下，碰撞也会造成船舶损毁的严重后果。作为判定结构是否失效的关键依据，失效准则对碰撞仿真分析结果的准确性有着至关重要的影响。本文针对典型的船体双层壳结构，结合试验数据，对比尖刀型撞头碰撞仿真下双层壳结构的塑性变形，对碰撞有限元模型及材料本构参数进行验证。在此基础之上重点研究GL、RTCL和JC工程上3种常用金属延性失效准则在碰撞破坏仿真分析中的应用。结果显示：板壳结构在碰撞载荷下，撞击中心的应力三轴度在0.3～0.6之间，考虑应力三轴度的RTCL和JC失效准则更能真实反应板的撞击破坏。而船舶碰撞多属于低速碰撞，应变率效应影响较小。
Failure of the ship structure attracts more and more attention recently. Collision is considered to be one of the most common damage for the structure and can sharply shorten its lifespan. Since the weight of the ship is sometimes very large, serious damage can still happen even with a low impact velocity. In order to know whether the failure occurs on a structure or not during the simulation, the failure criteria is always used and affects the analysis a lot. The present paper compares the effect of three different types of failure criterion on numerical results. Firstly, suitable parameters in the finite element method are chosen and validated by comparing with experimental data in modelling the typical double shell collision model. After that, the application of three types of failure criterion, namely the GL, RTCL, and JC models, are discussed. Results show that the triaxiality greatly affect the accuracy of the simulation, while the strain rate has much less effect especially under low impact velocity.
2017,39(1): 56-62 收稿日期：2016-04-22
DOI：10.3404/j.issn.1672-7619.2017.01.012
分类号：U661.43
基金项目：国家自然科学基金资助项目（10702022）；华中科技大学青年教师基金资助项目（0114140034）
作者简介：张志强(1991-),男,硕士研究生,研究方向为冲击动力学及船舶与海洋工程结构物设计制造。
参考文献：
[1] HONG L. Simplified analysis and design of ships subjected to collision and grounding[D]. Norwegian University of Science and Technology,2009.
[2] HARIS S, AMDAHL J. An analytical model to assess a ship side during a collision[J]. Ships and Offshore Structures, 2012, 7(4):431-448.
[3] 温小飞, 卢金树, 崔振东. 船舶碰撞过程的数值模拟及试验研究[J]. 浙江海洋学院学报(自然科学版)2011, 30(1):71-76. WEN Xiao-fei, LU Jing-shu, CUI Zhen-dong. Numerical simulation and experimental research of ship collision process[J]. Journal of Zhejiang Ocean University(Natural Science), 2011, 30(1):71-76.
[4] JEN C Y, TAI Y S. Deformation behavior of a stiffened panel subjected to underwater shock loading using the non-linear finite element method[J]. Materials & Design, 2010, 31(1):325-335.
[5] MCDERMOTT J F, KLINE R G, JONES E L, et al. Tanker structural analysis for minor collisions[J]. Trans. SNAME, 1974, 82:382-414.
[6] SUZUKI K, OHTSUBO H, SAJIT C. Evaluation of absorbed Energy in collision of ships-the effectiveness of minorsky's formula in anti-collision structure[J]. J Soc Naval Architects of Japan, 1999, 186:311-317.
[7] PAIK J K, CHUNG J Y. On the collision strength of ship's bow[A]//. Proceeding of the 7th international Offshore and Polar Engineering Conference, Honolulu. 1997:396-402.
[8] SCHARRER M, ZHANG L, EGGE E D. Final report MTK0614, collision calculations in naval design systems:report Nr. ESS, 2002.183 Version 1/2002-11-22[R]. Germanischer Lloyd, Hamburg, 2002.
[9] RICE J R, TRACEY D M. On the ductile enlargement of voids in triaxial stress fields[J]. Journal of the Mechanics and Physics of Solids. 1969, 17:201-217.
[10] PESCHMANN J, KULZEP A. Final report for BMBF Life-Cycle Design. Part D2A:Side collision of double skin ships[R]. Technical University of Hamburg, 2000.
[11] JOHMSON G R, COOK W H. Fracture characteristics of three metals subjected to various strains, strain rates, temperatures and pressures[J]. Engineering Fracture Mechanics. 1985, 21(1):31-48.
[12] VILLAVICENCIO R, KIM Y H, CHO S R, et al. Deformation process of web girders in small-scale tanker double hull structures subjected to lateral impact[J]. Marine Structures. 2013, 32(3):84-112.
[13] 孔祥韶. 爆炸载荷及复合多层防护结构响应特性研究[D]. 武汉:武汉理工大学, 2013. KONG Xiang-shao, Research on the blast loadings and the response of multi-layer protective structure[D].Wuhan:Wuhan University of Technology, 2013.
