某散货船舱口围肘板趾端开裂原因及节点优化方案分析

文章首先分析了某46 000 DWT散货船纵向舱口围端部肘板趾端开裂的原因,根据分析结果提出了节点优化方案;采用有限元直接计算的分析方法比较了修改前后节点的应力状况,并进行验证;提出了舱口围端部肘板修复时切割、装配和焊接的要求。研究结果为散货船舱口围板高应力区域的节点设计提供了理论和实船验证依据。     

中小型集装箱船舱口围板应力与变形控制方法

在分析建造规范的相关规定的基础上,对1100TEU集装箱船大开口甲板舱口围板进行了变形分析和评估,讨论在船体发生总纵弯曲时,舱口角隅应力集中发生的原因,通过对舱口围板的装焊技术的分析,对原有舱口围板装焊方法提出改进措施,仿真计算结果表明,新型装焊技术对舱口围板处应力分布和变形有极大的改善作用。     

散货船连续纵向舱口围板设计

综合考虑散货船设计面临的结构轻量化需求和纵向舱口围板趾端和舱口角隅容易产生裂纹的问题,以21万t散货船为例,提出一种连续的纵向舱口围板结构设计方案。结合HCSR规范,采用有限元分析方法,研究连续纵向舱口围板对整个主甲板区域重量以及对舱口角隅应力和疲劳的影响,结果表明,连续纵向舱口围板方案在散货船上是可行的,该方案可使整个甲板区减重41.54 t,而且舱口角隅处的应力水平和疲劳强度比传统方案有所改善,应力水平下降4.69%,疲劳寿命提高37.64%。与传统的不连续纵向舱口围板相比,连续纵向舱口围板设计方案可实现散货船结构轻量化,消除了舱口围板趾端疲劳裂纹隐患,降低了舱口角隅应力水平。     

超大舱口集装箱船舱口围板的强度分析及连续性的处理

本文以４０００ＴＥＵ级巴拿马型集装箱船为基础，采用计算和比较方法，通过对超大舱口集装箱船纵向连续舱口围板在弯扭时的受力与变形特性及其在船体梁弯扭中的作用分析，结合纵向舱口围板高度变化对船中剖面模数影响的统计分析，提出超大舱口集装箱船舱口围板结构形式及连续性处理方法。     

多用途船舱口围板变形约束有限元校核技术

考虑28 000 DWT多用途船的中间货舱纵向长度过长,舱口围板容易发生变形,为控制舱口围板变形量的大小,在舱口盖与舱口围板顶板接触处设置Semi-fix(有限限制止动系统)来抑制舱口的变形,使舱口围板的变形量始终保持在舱口动作可接受的正常范围内。     

8530 TEU集装箱船舱口盖导向装置碰撞分析

对8530TEU集装箱船舱口围、舱口盖及其导向装置进行合理简化后,综合应用CAE软件仿真模拟了吊离式舱口盖与导向装置间的接触-碰撞过程.通过动力学仿真分析,得到了所关心的"最大碰撞力-碰撞速度"曲线、导向装置最大位移以及结构最大等效应力等参数.碰撞分析结果可为设计、分析此类结构的提供参考,所建的计算模型可以根据需要进行更加深入的研究.     

2339TEU舱口盖反加强错位有限元分析及其优化

利用MSC Patran和MSC Nastran对2339TEU集装箱船舱口围的强度以及舱口围面板的剪力进行有限元分析,为有效评估面板的剪力,对面板采用实体建模处理。通过有限元分析得到的结论可用于指导集装箱船舱口盖反加强的结构设计;计算结果表明优化后的结构既满足强度又满足施工工艺。     

散货船纵向舱口围的加强设计

散货船纵向舱口围支撑肘板的加强,通常是在对应位置的主甲板下加一块加强肘板。对于纵向舱口围支撑肘板的模数要求,规范中是有规定的,但对于支撑肘板在主甲板以下的加强结构的强度要求,一般规范中未作规定,因此常被设计人员所忽视。通过对一艘5万吨级散货船的纵向舱口围进行有限元分析,发现了原有主甲板以下舱口围加强设计中的缺陷,并提出了相应的解决办法。     

重吊船舶超大型舱口围板制造工艺的设计与实施

超大型舱口多用途重吊船舶，货舱的长度超过了船舶总长的二分之一，舱口围板材料为高强度钢，局部加强的厚度可达140mm.介绍了超厚型货舱围板在下料加工、制作和上船安装工艺，该工艺使超大型舱口超厚货舱围板的制造顺利完成。     

多用途船舱口盖的有限元分析及优化

文中针对多用途船的舱口盖上堆放集装箱的舱口盖进行有限元计算,得到舱口盖对应的应力分布和变形情况,提供一种舱口盖强度校核方法。同时研究不同板厚对舱口盖强度的影响,对舱口盖结构强度进行优化,使得舱口盖在较小的厚度下达到较高的强度,为以后舱口盖的设计提供依据。     

船舶舱口角隅疲劳强度及热点应力研究

舱口角隅部分的疲劳问题是疲劳分析的重要内容.本文建立了某船的全船有限元模型并分别采用嵌入式模型和外部模型对舱口角隅进行细化.比较不同的单元类型、热点应力选取方式对疲劳损伤的影响.同时采用直接计算的谱分析方法计算了舱口角隅的疲劳损伤.发现当选用最大主应力作为热点应力时实体单元计算结果较壳单元偏小.同一类型单元节点数目的不同对损伤结果影响不大.热点应力选取方式对疲劳损伤的计算影响较大,在对舱口角隅疲劳强度进行分析时建议选用最大主应力插值的方式计算热点应力.     

大开口船舱口角隅应力集中问题研究

建立了大开口船舶舱口角隅应力集中有限元计算模型,讨论了４种应力释放孔孔形以及无应力释放孔时舱口角隅处的应力分布情况,并讨论了加加厚板后的应力分布情况。从实用角度分析了应力释放孔和加加厚板的效果,为解决大开口船舶舱口角隅处应力集中问题提供了计算依据。     

基于过渡单元的有限元细化法在舱口角隅处的研究

针对集装箱船舱口角隅处的应力计算,提出一种针对舱口角隅处网格的自动有限元精细划分算法。在进行完整船有限元分析后,截取出局部舱口角隅模型进行网格细化,将粗网格计算结果作为细网格模型边界条件,再次进行有限元分析。结果表明细化网格分析能反映出应力梯度比较大的区域的应力变化情况,其分析结果好于整体分析结果。     

基于疲劳强度的超大型集装船角隅优化设计

对于集装箱船而言,货舱角隅处一般存在结构形式的突变,在船体梁发生弯曲、扭转变形时,角隅承受着较大的弯曲正应力及翘曲应力,存在较严重的疲劳问题。本文以MARIC设计的某20000 TEU级超大型集装箱船为例,介绍了货舱内20 ft角隅、箱角角隅及舱口角隅的优化设计思路,通过有限元方法验证了优化方案的有效性。     

Use of a 3D compartment model for simplified full ship FE model. Part II: validation of the simplified FE model

This is Part II in a series of papers. Part I (J Mar Sci Technol 13:154–163) deals with an approach employed to construct a simplified FE model using a 3D compartment model available from the beginning of the ship design process. This paper begins by describing the limitations of an analytical approach based on shear warping beam theory for assessing torsional strength. Next, the structural parts of a container ship that have a negligible effect on hull girder bending strength and torsional strength are determined. This is verified by removing these parts from a conventional FE model and comparing the results obtained using this modified model with those yielded by the original model. The fore end part, the aft end part and the deck house are examined. Since these parts have complicated structures and relevant drawings for them are issued later than cargo structure drawings, modeling them exactly can result in a delay in the completion of the full ship FE model. This paper also verifies the validity of the simplified FE model built by applying the method proposed in Part I and comparing the results obtained with it with those given by a conventional full ship FE model. The stresses on hatch coaming top, the maximum diagonal elongations of the hatch coaming, and the maximum hatch corner movements are evaluated to check the validity of the simplified model.     

3800箱集装箱船总纵强度计算两种方法对比研究

本文对3800箱集装箱船进行了整船有限元分析，计算了在设计静水弯矩、波浪弯矩、水平弯矩和扭矩作用下的船体总纵强度，并与基于薄壁梁扭转理论的总纵强度计算结果进行了比较，对两种方法的应用前景作出评论。     

等效波的散货船舱口角疲劳评估应力组合方法(英文)

The stress combination method for the fatigue assessment of the hatch corner of a bulk carrier was investigated based on equivalent waves.The principles of the equivalent waves of ship structures were given,including the determination of the dominant load parameter,heading,frequency,and amplitude of the equivalent regular waves.The dominant load parameters of the hatch corner of a bulk carrier were identified by the structural stress response analysis,and then a series of equivalent regular waves were defined based on these parameters.A combination method of the structural stress ranges under the different equivalent waves was developed for the fatigue analysis.The combination factors were obtained by least square regression analysis with the stress ranges derived from spectral fatigue analysis as the target value.The proposed method was applied to the hatch corner of another bulk carrier as an example.This shows that the results from the equivalent wave approach agree well with those from the spectral fatigue analysis.The workload is reduced substantially.This method can be referenced in the fatigue assessment of the hatch corner of a bulk carrier.     

大开口船波浪载荷长期预报和弯扭强度整船有限元分析

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。     

双体船波浪载荷及强度计算分析

双体船在横浪与斜浪中会遭受比较严重的横向弯矩和扭转力矩作用,此时双体船的强度对其安全性至关重要。本文采用波浪直接计算方法对本船在航行海区进行波浪载荷长期预报,得到各强度工况计算设计波。采用直接计算方法对双体船进行了总纵强度、横向强度和扭转强度的整船有限元分析,对计算结果分析该船在各工况下的应力分布,结果表明该船结构强度满足要求,但高盈利区域出现在抗扭箱与片体连接处,针对该危险区域提出修改方案,为其他类似船舶设计提出参考意见。     

On board measurement of stresses and deflections of a Post-Panamax containership and its feedback to rational design

One of the most important points in structural design of containerships is the strength of hatch corners. Formerly, hatch corners used to be assessed by combining the component induced by hull girder vertical bending and the component induced by hull girder torsion. In the design of new generation containerships without deck girders, the effect of cross deck fore-aft deflection has also become prominent.Another point is the impact of structural displacement on the deck fittings. About new generation ships, large fore-aft deflection of cross decks raised the new problem of interference of hatch covers, lashing bridges and other deck fittings.To cope with such problems, comprehensive analysis has been carried out during the design stage of a Post-Panamax containership. In parallel with this analysis, on-board measurement had been conducted for 3 years after delivery, in order to confirm wide varieties of structural reaction of a large container ship in seaways. Procedure to derive components of stress and deformations from selected measurement points was developed, and actual values were calculated based on actual measurement.From long-term prediction of each component, it was found that design assumption was in general appropriate. However, regarding the fore-aft deflection of cross deck strip, actual stack load is generally much smaller than the design value, and the resulting predicted extreme value was much smaller than design assumption. This factor should be taken into account in the design stage.Regarding the correlation between hull girder vertical bending and fore-aft deflection of cross deck strip, design assumption of full combination is too conservative. From the measurement, no explicit correlation was observed. Regarding the correlation between hull girder vertical bending and wave induced torsion, design assumption of no correlation was appropriate. From these results, new formulae to combine these three deflection modes were proposed.Whipping was observed in the measured data, indicating that more careful attention should be paid to avoid large stress concentration in deck area to enhance fatigue strength.