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Use of 3D compartment model for simplified full ship FE model. Part I: construction of FE model 总被引:1,自引:1,他引:0
Beom-Seon Jang Jae-Hoon Jung Yong-Suk Suh 《Journal of Marine Science and Technology》2008,13(2):154-163
Classification societies cannot cover the torsional strength assessment with simple empirical formula as the size of a containership
increases drastically over 10 000 TEU in recent years. Torsional strength of a container ship is very difficult to estimate
with an analytical method due to its alternatively varying cross sections, i. e. an open and a closed section. This article
proposes an approach to construct a simplified FE model using a 3D compartment model available from the beginning of ship
design process. The model is cut to pieces of lots of small pieces of lines by a set of transverse, longitudinal and horizontal
planes. Two algorithms are developed for mesh generation of internal structures; one for assembling the broken lines into
closed loops and the other for automatically generating mesh from the loops. Another algorithm is proposed to generate mesh
for outer hull using outermost nodes of the FE model built for internal members. The validity of the simplified model is discussed
along with a beam theory based approach in J Mar Sci Technol (2008) 相似文献
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《Marine Structures》2004,17(5):355-384
Container ship structures are characterized by large hatch openings. Due to this structural property, they are subject to large diagonal deformations of hatch openings and warping stresses under complex torsional moments in waves. This necessitates torsional strength assessment of hull girder of container ships in their structural design stage. In this paper, a practical method for torsional strength assessment of container ship structures with transparent and consistent background is discussed based on the results from up-to-date analyses. In order to estimate the torsional response characteristics as accurately as possible, three-dimensional Rankine source method, after being validated by tank tests, is employed for estimation of wave loads on a container ship, and FE analyses are conducted on the entire-ship model under the estimated loads. Then, a dominant regular wave condition under which the torsional response of the container ship becomes maximum is specified. Design loads for torsional strength assessment that give torsional response equivalent to the long-term predicted values of torsional response are investigated based on the torsional moments on several container ships under the specified dominant wave condition. An appropriate combination of stress components to estimate the total hull girder stress is also discussed. 相似文献
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大开口船波浪载荷长期预报和弯扭强度整船有限元分析 总被引:11,自引:1,他引:10
大开口船全船弯扭联合变形与应力的精确计算,必须在整船结构模型上完成。本文以一艘5万吨级大开口船为例,用三维流体动力计算程序进行了波浪随机载荷的长期预报,并在此基础上导出设计波参数组,进而在全船整体结构有限元模型上计算了船体结构在各设计波上的应力分布,并采用嵌入精细舱口角区有限元网络的方法,在整船分析的同时计算出舱口角的应力集中值,获得了船体结构强度的详尽信息。文中阐述了波浪载荷的特点,设计波的确定,浮体完整结构计算的惯性平衡及大开口船的全船计算方法。 相似文献
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大型集装箱船舱盖布置适应性研究 总被引:1,自引:0,他引:1
随着国际航运市场的发展,大型集装箱船不断涌现。文章拟通过分析大型集装箱船的船体变形,研究如何对舱盖板进行合理分块,协调布置舱口盖相关装置,以充分满足航行过程中舱口盖适应船体结构大开口变形的问题。 相似文献
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This is the second of two companion papers dealing with nonlinear finite element modelling and ultimate strength analysis of the hull girder of a bulk carrier under Alternate Hold Loading (AHL) condition. The methodology for nonlinear finite element modelling as well as the ultimate strength results from the nonlinear FE analyses was discussed in the companion paper (Part 1). The purpose of the present paper is to use the FE results to contribute towards developing simplified methods applicable to practical design of ship hulls under combined global and local loads. An important issue is the significant double bottom bending in the empty hold in AHL due to combined global hull girder bending moment and local loads. Therefore, the stress distributions in the double bottom area at different load levels i.e. rule load level and ultimate failure load level are presented in detail. The implication of different design pressures obtained by different rules (CSR-BC rules and DNV rules) on the stress distribution is investigated. Both (partially) heavy cargo AHL and fully loaded cargo AHL are considered. Factors of influence of double bottom bending such as initial imperfections, local loads, stress distribution and failure modes on the hull girder strength are discussed. Simplified procedures for determination of the hull girder strength for bulk carriers under AHL conditions are also discussed in light of the FE analyses. 相似文献
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介绍约束扭转计算原理,分析集装箱船的结构和受力特点,利用MSC/Nastran软件探讨了集装箱船的扭转强度计算方法。在现有结构形式的基础上,提出几种可能提高结构扭转强度的结构加强方案,通过有限元分析比较各方案对于增加同样重量的钢料船体结构中翘曲应力变化情况,比对抗扭效果,研究在考虑成本基础上提高集装箱船抗扭强度的加强方案优先顺序,结果显示对于支线型集装箱船增加舱口围厚度可更有效提高其抗扭强度。 相似文献
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In a Thermal-Elastic-Plastic (TEP) FE analysis to investigate welding induced buckling of large thin plate welded structure such as ship panel, it will be extremely difficult to converge computation and obtain the results when the material and geometrical non-linear behaviors are both considered. In this study, an efficient FE computation which is an elastic FE analysis based on inherent deformation method, is proposed to predict welding induced buckling with employing large deformation theory, and an application in ship panel production is carried out. The proposed FE computation is implemented with two steps:(1) The typical weld joint (fillet weld) existing in considered ship panel structure is conducted with sequential welding using actual welding condition, and welding angular distortion after completely cooling down is measured. A TEP FE analysis with solid elements model is carried out to predict the welding angular distortion, which is validated by comparing with experimental results. Then, inherent deformations in this examined fillet welded joint are evaluated as a loading for the subsequent elastic FE analysis. Also, the simultaneous welding to assemble this fillet welded joint is numerically considered and its inherent deformations are evaluated.(2) To predict the welding induced buckling in the production of ship panel structure, a shell element model of considered ship panel is then employed for elastic FE analysis, in which inherent deformation evaluated beforehand is applied and large deformation is considered. The computed results obviously show welding induced buckling in the considered ship panel structure after welding. With its instability and difficulty for straightening, welding induced buckling prefers to be avoided whenever it is possible. 相似文献
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Verification of a simplified analytical method for predictions of ship groundings over large contact surfaces by numerical simulations 总被引:1,自引:0,他引:1
In this paper, a verification is presented of a simplified analytical method for the predictions from numerical simulations of structural performance during ship groundings over seabed obstacles with large contact surfaces and trapezoidal cross-section. This simplified analytical method was developed by Lin Hong and Jørgen Amdahl and calculates grounding characteristics, such as resistance and distortion energy, for double-bottomed ships in shoal grounding accidents. Two finite-element models are presented. One was built for a hold, and the other was built for a hold and a ship hull girder and also considers sectional properties, ship mass, added mass and the hydrodynamic restoring force. The verification was completed by comparing horizontal and vertical resistances and the distortion energy between seven numerical-simulation cases and a set of corresponding cases computed by a simplified analytical method. The results show that the resistances obtained by the simplified analytical method are close to the mean values of the resistance curves obtained by numerical simulations. The comparisons prove that the energy dissipation-prediction capability of the simplified analytical method is valuable. Thus, the simplified analytical method is feasible for assessing ship groundings over seabed obstacles with large contact surfaces and trapezoidal cross-section. Furthermore, studies of the influence of ship motion during groundings ascertained that ship motion affects structural performance characteristics. Resistances are lessened at the end of the grounding due to the reduction of indentations caused by heave and pitch motions of the ship hull girder. Finally, a new method for predicting the structural performance of the time-consuming complete-ship model by applying a combination of normal numerical simulations and ship-motion calculations is proposed and proven. 相似文献
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随着造船业飞速发展,大量高厚度、高强度、高韧性的钢板被应用于大型集装箱船的上甲板区域。EH47是工业革新的最新成果,它的屈服强度高,被使用于万箱级集装箱船的上甲板区域。某船厂10000 TEU船舱口围钢板与舾装件角焊缝发生开裂,通过有限元计算出裂纹发生的可能性,并分析了开裂发生的原因,针对结构特点和材料特点,采用CO2气体保护焊焊补,通过选用合理的焊丝、预热温度、焊后保温等措施来防止裂纹的产生。 相似文献
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垂向可调尾板在尾流场中有限元分析 总被引:1,自引:0,他引:1
垂向可调尾板是设于某类型船舶尾封板水线以下,能实时调整该类型船舶航行姿态,使之在该航速下具有最佳阻力及运动性能的机构。对此尾板进行了有限元分析,采用ANSYS CFD模块对尾部流场进行了模拟,并对尾板结构强度进行校核,并将此结果与经验公式结果进行对比分析,提出了优化设计的途径。 相似文献
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This paper provides a new contribution to the simplified analytical treatment of collisions between two ships. It is directly connected to the well-known super-elements method, which is a simplified procedure allowing for a quick estimation of the damages caused to both the striking and struck vessels during such events. In this article, a new analytical formulation is presented for estimating the impact resistance provided by inclined ship side panels. Two different scenarios are treated. We first deal with the case of an impact between the oblique plate and the stem of the striking ship, and then we consider the situation where the inclined panel is impacted by the bulb. For these two scenarios, an analytical formulation relating the force and the penetration is provided and these developments are validated by comparing them to the results of finite elements simulations. Finally, the new inclined plate super-element is integrated in a simplified model of a frigate collided by another ship, and the resistance given by the super-elements method is then compared to the one obtained by a numerical simulation of this collision. 相似文献
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3 100 TEU集装箱船扭转强度研究 总被引:1,自引:0,他引:1
本文以3 100 TEU集装箱船为研究对象,参照德国劳氏船级社的GL RULES对集装箱船的要求,应用德国船级社(GL)的GL-DECKFRAME软件建立舱口围扳架模型,对其进行扭转强度计算与分析,得出了最大静水扭矩,总扭矩,波浪水平弯矩,纵向舱口围板最大翘曲应力、应变;并计算出舱口角隅各个方向的最大综合应力;根据结果,提出了优化的舱口板架结构方案。 相似文献
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介绍了一艘超大型矿砂船在施加舱口盖载荷工况下,对相关的横向强框结构局部强度进行解析法分析。通过有限元法对强框处屈服、屈曲强度进行分析评估和理论验证。对比了国际船级社协会(IACS)《船舶结构强度》统一要求第21条(URS21)规定的舱口盖载荷均布施加于舱口围和实际集中载荷的四种不同工况下的结果 ,依据结果进行了结构合理加强。其分析结果与加强方案对超大型矿砂船局部强度分析具有一定的参考价值。 相似文献