10000箱大型集装箱船典型货舱结构极限强度

目前集装箱船的运力越来越大,在追逐高效设计的时候往往忽视了结构的安全可靠性,近10年里有多艘大型集装箱船发生了安全营运事故,甚至有2条在海上直接发生船体结构失效折断的恶性事件,据调查其在设计中低估了结构承载能力。为了保证大型集装箱船在营运中使用的安全性和航行时结构的可靠性,国际船级社协会专门组织部长级会议研讨提高载荷设计值,要求评估典型货舱结构的极限强度,修改集装箱船的规范要求,以此避免今后大型集装箱船再次遭遇严重事故。本文针对1艘10 000箱大型集装箱船的典型货舱结构,基于逐步破坏法和非线性有限元法,分别计算了垂向和水平方向的极限强度,以及垂向和水平联合作用下的极限强度。计算结果表明,在初步设计阶段评估大型集装箱船的货舱结构极限强度时,可以采用规范要求的逐步破坏法,但是考虑到海上波浪环境条件的恶劣性,以及集装箱船自身结构的特殊性,应该利用非线性有限元法进行直接计算。     

循环载荷下大开口箱型梁弯曲极限强度试验研究

甲板大开口已成为现代货运船舶结构的典型特征，但是甲板大开口的存在不仅削弱了船体结构的极限承载能力，也使其性能与响应更加复杂。基于模型试验与非线性有限元法探究了设计的甲板大开口箱型梁在中垂循环极限弯矩作用下的结构承载能力与破坏模式，分析初始缺陷和材料硬化效应对结构极限强度的影响。结果表明，在循环载荷作用下，模型的塑性变形随着循环次数增加而逐步累积，屈曲破坏将从甲板板扩展到舷侧板；模型即使发生屈曲破坏，仍保留了大部分承载能力；材料硬化效应在循环极限加载中影响较小。研究结果可为大开口船舶结构的安全性评估和优化设计提供指导。     

大型液化天然气船船体极限强度研究

船体极限强度是大型液化天然气(LNG)船海洋环境适应能力的显示指标,而薄膜型LNG船的船体结构具有大舱容和较强的箱形凸起甲板等特点。为了精确评估大型LNG船的船体极限承载能力,文中采用具有代表性的解析方法、简化方法、理想结构单元法和非线性有限元法进行比较研究。首先介绍了上述方法的基本原理和计算步骤。然后以大型LNG船的船中肋骨间结构为研究对象建立了精细的计算模型,并对计算结果进行了比较分析。最后,按法国船级社规范要求对大型LNG船极限强度进行了校核。研究结果表明,文中给出的计算方法适合于大型LNG船的船体极限强度评估,而凸起的箱形甲板显著提高了大型LNG船中垂和中拱极限弯矩比值。     

大型液化天然气船船体极限强度研究

船体极限强度是大型液化天然气(LNG)船海洋环境适应能力的显示指标,而薄膜型LNG船的船体结构具有大舱容和较强的箱形凸起甲板等特点.为了精确评估大型LNG船的船体极限承载能力,文中采用具有代表性的解析方法、简化方法、理想结构单元法和非线性有限元法进行比较研究.首先介绍了上述方法的基本原理和计算步骤.然后以大型LNG船的船中肋骨间结构为研究对象建立了精细的计算模型,并对计算结果进行了比较分析.最后,按法国船级社规范要求对大型LNG船极限强度进行了校核.研究结果表明,文中给出的计算方法适合于大型LNG船的船体极限强度评估,而凸起的箱形甲板显著提高了大型LNG船中垂和中拱极限弯矩比值.     

船体梁弯曲极限强度分析

针对船体梁极限强度计算问题,研究基于弯曲承载力的极限状态分析技术。分析总结船体梁极限强度分析方法及研究现状,阐述简化逐步破坏法(Smith逐步破坏法)的技术流程,探讨基于非线性有限元极限强度分析技术中各参数设置对计算结果的影响。在简化逐步破坏法计算结果的基础上,利用非线性有限元法评估基于单跨模型和舱段模型的船体梁极限强度,并探究上层建筑对极限承载力的影响。     

8 530 TEU大型集装箱船船中货舱区舱口角隅疲劳强度校核

集装箱船货舱区舱口角隅疲劳强度校核是集装箱船强度分析的重要内容之一,该文选择沪东中华造船(集团)有限公司即将建造的8 530 TEU集装箱船船中No.5货舱区Fr181处角隅作为疲劳强度分析对象.基于设计波法,选择全球航行海域波浪散布图进行波浪诱导载荷长期预报,获得四种典型的波浪载荷参数,然后在一个波浪循环内每隔30°取一相位,计算了其中三种最典型波浪载荷工况下上甲板角隅边缘和舱口围板角隅边缘的热点应力,确定最大应力范围及其位置,最后基于S-N曲线法进行疲劳强度校核.     

大型集装箱船在斜浪工况下的扭矩特征研究及结构强度分析

随着大型集装箱船的发展,针对斜浪条件下扭矩载荷特性及其结构强度的分析研究日益重要.本文采用选定的某大型集装箱船开展动态载荷(DLA)分析,建立了水动力湿表面计算模型和质量模型,研究基于扭矩传递函数和主要载荷控制参数的斜浪设计波参数确定方法,分析超越概率水平对扭矩载荷计算结果的影响.考虑典型斜浪参数和超越概率水平,分析对比DLA扭矩与船舶规范(ABS和HCSR)扭矩的差异及原因,提出集装箱船扭矩载荷计算与应用的建议.在此基础上,选定3个斜浪计算工况(45°,60°和75°)开展结构强度分析,通过分析应力计算云图,研究扭矩载荷下船体结构响应的关键位置及其应力趋势.该研究可为大型集装箱船结构设计过程中船体梁扭转强度计算、舱口角隅设计、抗扭箱强度评估等方面提供有益的参考.     

双燃料集装箱船中货舱典型舱段有限元分析

针对双燃料集装箱船燃油舱布置在水密横舱壁的特点,其存在一系列高应力区域,具有结构硬点的节点设计存在一定难度。基于BV规范要求,对某大型甲醇双燃料集装箱船中货舱船体结构开展舱段有限元计算分析,并进行优化设计;对于较难处理的节点,采用子模型法对重点关注区域进行细网格分析,比较各种优化节点形式对节点受力的改善。     

支线集装箱船整船强度和疲劳有限元分析

在分析UR S11A和S34生效后的集装箱船整船屈服、屈曲要求的基础上,以1艘支线集装箱船为对象,计算得到目标船整船结构各个计算工况下的应力分布,完成整船屈服、屈曲强度评估和疲劳筛选及评估,分析发现支线集装箱船艏、艉非货舱区域结构和货舱区域的横向结构,以及整船重点区域的疲劳问题不容忽视.在设计时,对上述区域结构应重点关...     

大型集装箱船高强度厚钢甲板安全寿命评估方法

疲劳是船舶与海洋工程结构破坏的主要模式之一.高强度钢的应用使得结构的疲劳问题更加突出.对于采用以高强度厚钢板为甲板的大型集装箱船来说,有必要进行高强度厚钢板的焊接缺陷部位安全寿命评估方法研究.以应力范围的长期分布服从两参数Weibull分布的随机载荷为疲劳载荷,裂纹扩展率采用单一曲线模型预报裂纹在任意时刻的尺寸,结合应力强度因子并参考应力计算方法和失效评估图技术提出一套计算集装箱船高强度钢厚钢板安全寿命评估的方法.通过编制计算程序,对某集装箱船甲板进行安全寿命计算.最后,分析疲劳载荷谱对安全寿命的影响.计算结果表明：载荷回复期的长短和Weibull分布的形状参数的取值都会极大影响结构疲劳安全寿命.     

Ultimate strength of container ships subjected to combined hogging moment and bottom local loads part 1: Nonlinear finite element analysis

This paper is the first of two companion papers concerning the ultimate hull girder strength of container ships subjected to combined hogging moment and bottom local loads. In the midship part of container ships, upward bottom local loads are usually larger than the downward ones. This leads to the increase of biaxial compression in the outer bottom plating and the reduction of the ultimate hull girder strength in the hogging condition. In this Part 1, the collapse behavior and ultimate strength of container ships under combined hogging moment and bottom local loads are analyzed using nonlinear finite element method. Buckling collapse behavior of bottom stiffened panels during the progressive collapse of a hull girder is closely investigated. It has been found that major factors of the reduction of ultimate hogging strength due to bottom local loads are (1) the increase of the longitudinal compression in the outer bottom and (2) the reduction of the effectiveness of the inner bottom, which is on the tension side of local bending of the double bottom. The obtained results will be utilized in the Part 2 paper to develop a simplified method of progressive collapse analysis of container ships under combined hogging moment and bottom local loads.     

Ultimate strength of container ships subjected to combined hogging moment and bottom local loads,Part 2: An extension of Smith's method

This paper is the second of two companion papers concerning the ultimate hull girder strength of container ships subjected to combined hogging moment and bottom local loads. The nonlinear finite element analysis in Part 1 has shown that local bending deformation of a double bottom due to bottom lateral loads significantly decreases the ultimate hogging strength of container ships. In this Part 2, extending Smith's method for pure bending collapse analysis of a ship's hull girder, a simplified method of progressive collapse analysis of ultimate hogging strength of container ships considering bottom local loads is developed. The double bottom is idealized as a plane grillage and the rest part of the cross section as a prismatic beam. An average stress-average strain relationship of plate/stiffened plate elements employed in Smith's method is transformed into an average stress-average plastic strain relationship, and implemented in the conventional beam finite element as a pseudo strain hardening/softening behaviors. The extended Smith's method is validated through a comparison with nonlinear finite element analysis.     

DNV GL新规范对大型集装箱船结构设计的影响

从总纵强度、舱段有限元和典型结构局部强度三个方面解析了DNVGL规范与GL规范在集装箱船结构方面的内容差异。以一艘14500TEU集装箱船为算例，分析了DNVGL规范对大型集装箱船结构设计的影响。结果表明，DNVGL规范对于集装箱船的总纵强度和舱段有限元提出了更高的要求，而在压载舱边界结构和艏部砰击方面的要求相对于GL规范有所降低，存在一定的优化空间。     

多用途船集装箱装载工况直接计算分析

多用途船的货舱内装载集装箱的固定形式与普通集装箱船不同,船级社及船舶的设计、建造方对此类船舶结构强度的安全性和可靠性投入更多的关注。为此,参照中国船级社钢质海船入级规范的要求,研究提出了舱内载荷的模拟方法,以某多用途船舱段结构强度有限元计算分析为例,分析研究集装箱横向运动和垂向运动惯性力对船体结构强度的影响。为多用途船装载集装箱工况的结构设计提供准确的分析方法。     

货舱内装载水冷箱的通风数值模拟分析

采用数值模拟分析的方法,以装载水冷式冷藏集装箱船的典型货舱为研究对象,对两种货舱通风模式进行模拟分析,并进一步计算分析4种不同风管布置方案的温度和速度分布情况,根据研究结果得出最佳的货舱通风方案,为装载水冷式冷藏集装箱船的货舱通风设计提供参考。     

Design safety margin of a 10,000 TEU container ship through ultimate hull girder load combination analysis

Assessment of the ultimate longitudinal strength of hull girders under combined waveloads can be of particular importance especially for ships with large deck openings and low torsional rigidity. In such cases the horizontal and torsional moments may approach or exceed the vertical bending moment when a vessel progresses in oblique seas. This paper presents a direct calculation methodology for the evaluation of the ultimate strength of a 10,000 TEU container ship by considering the combined effects of structural non-linearities and steady state wave induced dynamic loads on a mid ship section cargo hold. The strength is evaluated deterministically using non-linear nite element analysis. The design extreme values of principal global wave-induced load components and their combinations in irregular seaways are predicted using a cross-spectral method together with short-term and long-term statistical formulations. Consequently, the margin of safety between the ultimate capacity and the maximum expected moment is established.     

Compartment level progressive collapse analysis of lightweight ship structures

The continued development of large high speed ships, often constructed from aluminium alloy, has raised important issues regarding the response of lightweight hull girders under primary hull girder bending. In particular, the response of lightly framed panels in compression may be influenced by overall panel buckling over several frame spaces. Therefore, to provide improved ultimate strength prediction for lightweight vessels, an extended progressive collapse methodology is proposed. The method has capabilities to predict the strength of a lightweight aluminium midship section including compartment level buckling modes. Nonlinear finite element analysis is used to validate the extended progressive collapse methodology.     

Experimental and numerical investigations of the ultimate torsional strength of an ultra large container ship

Structures of ultra large container ships (ULCS) are characterized by large deck openings and low torsional rigidity. It is essential to comprehensively figure out their collapse behaviors under pure torsion with both model experiments and numerical simulations, making an evaluation of their ultimate torsional strength. In this paper, a similar scale model of a 10,000TEU container ship has been designed and manufactured first, in which both geometric similarity and strength similarity are taken into account. Next the collapse behaviors of the test model are detailedly illustrated with both experimentally and numerically obtained results. Then discussions on warping or shear buckling deformations involved in the collapse process of the structure are conducted with extended numerical simulations. Finally, the ultimate torsional strength of the true ship is evaluated according to the similarity theory. Results show that it is the yielding and shear buckling of the side shells that causes the failure of the hull girder under pure torsion. Further nonlinear finite element analysis demonstrates that it may either have warping or shear buckling deformations in the torsional collapse process of the hull girder with a large deck opening, depending on the local rigidity distribution of side shells, which has a significant effect on the ultimate torsional strength of the hull girder.     

32000DWT散货船货舱段结构强度分析

利用MSC／Patran、MSC／Nastran软件分析了32000DWT散货船货舱段强度。给出了外载荷的计算方法和边界条件的施加方法,计算了典型的3种工况下32000DWT散货船的强度。通过有限元强度分析得到的结论可用于散货船的结构设计和优化。计算结果表明,本船的结构强度满足规范要求。