超大型集装箱船甲板最大堆重研究

德国劳氏船级社规范(GL-2013)对集装箱船尤其是超大型集装箱船的横向加速度系数计算进行了调整,大幅度提高了甲板上集装箱堆重。文章根据绑扎计算结果,将规范变化前后的横向加速度系数和最大堆重进行对比,以及对2层箱高绑扎桥和3层箱高绑扎桥的最大堆重进行对比。结果显示,随着规范的更新及绑扎点高度提高,集装箱甲板最大堆重显著增加,堆重分布更加优化合理,为今后超大型集装箱船甲板面堆重设计参数的合理选取提供了一定的参考。     

大型集装箱船甲板堆重的影响因素

以某14 500 TEU集装箱船为对象,基于DNV GL规范对影响集装箱船甲板堆重的主要因素进行分析。首先介绍新规范采用的横向加速度系数计算方法,对比新旧方法对甲板许用最大堆重的影响;然后对比分析绑扎形式以及绑扎桥层数对甲板许用最大堆重和系固系统设计的影响。结果表明:随着规范的更新,集装箱横向加速度系数明显降低;同时,由于采用外绑形式和3层绑扎桥,大型集装箱船甲板堆重能力明显提高,但这也对集装箱系固系统设计带来了一些新的影响。     

集装箱系固计算综述

针对集装箱船航行过程中集装箱的运输安全,探讨了集装箱系固的计算方法。以德国劳氏规范和中国CCS规范为依据,分析了集装箱的受力及力的传递与分配,重点阐述了集装箱堆重计算的原理。并以堆重计算为基础,介绍了捆扎计算的基本方法。希望对集装箱船的结构设计以及舾装设计有参考作用。     

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.     

2500TEU内贸集装箱船船型开发设计

针对内贸箱船货运近海航行,重箱化及散货集装箱化的需求,对2500TEU级内贸箱船船型的开发思路与各方面的特点作了介绍。该船型具有低航速、大载重吨、高装箱率、快捷牢靠堆装系统的特点,目前已成功升级了第二代2500TEU船型。     

Experimental and numerical investigation of lashing bridge and container stack dynamics using a scaled model test

Previously reported container losses were generally attributed to extremely violent motions of containerships due to adverse weather conditions. However, most existing specifications or standards adopted for containers and lashing equipment meet the requirement of static conditions. Hence, further researches on safer container shipping under heavy sea states are required. Consequently, an experimental study method is proposed to measure the dynamic response of 1/10 scaled lashing bridge and container stack. The scaled model of the lashing bridge is constructed based on the similarity theory. Based on two dimensionless numbers, Froude's number and Cauchy's number, eleven container scaled models are employed. A series of experiments with controlled parameters are performed using a three-degrees shaking table (roll, pitch, heave) to present sufficient data to verify the effectiveness of the numerical model. The results of experiments, numerical simulations and calculations of the VERISTAR procedure (developed according to the BV rule) are compared. This study aimed to explore the mechanical behavior of the lashing bridge and container stack under predetermined driving excitations (roll and pitch) which simulated heavy sea states. According to the results, the model can predict conditions similar to real situations of the lashing bridge and container stacks while storages on the weather deck.     

Statistical study of lashing forces measured on-board a PCTC vessel

Lashing forces and reaction forces between the car tyres and ship deck were measured on-board a PCTC vessel operating in the North Atlantic and statistically evaluated. A study was done of the characteristics of lashing forces and defined required friction coefficient. The lashing forces and the required friction coefficient were found to be small. The influence of wave direction on the forces was also small.     

超大型集装箱船绑扎桥强度校核与结构优化

随着超大型集装箱船的发展,绑扎桥的结构设计越来越复杂。文章在21000TEU超大型集装箱船典型绑扎桥设计的基础上,利用ANSYS软件计算了绑扎桥结构的强度和刚度。通过研究不同浮态,装箱条件以及最大设计载荷条件下结构的总体应力和变形情况,分析了关键位置的应力集中现象。并用这些分析结果指导结构优化,为绑扎桥结构的分析及结构设计提供具指导意见。     

无舱盖集装箱船（HCS）完整稳性的计算研究

在进行７００ＴＥＵ无舱盖集装箱的常规集装箱船方案设计的基础上，可两船型的完整稳性作了对比研究。结果表明：从满足稳性的要求出发，无舱盖集装箱船可以多装载集装箱的数量为总箱数的５％￣１０％，经济效益明显，本文还从满足无舱盖集装箱船货舱进水后稳性的残存衡准出发，探讨了确定排水舷口高度的方法。     

集装箱在舱面堆装重量的限制

按照我国现行规范的规定，作者编制了船舶舱面集装箱及其系固设备受力计算与校核系统计算程序。根据对我国规范和该计算程序运行结果的研究，本文首先分析了影响集装箱在船上受力的主要因素，在提出确定集装箱在舱面堆装重量限制临界条件的基础上，阐述了绘制集装箱在舱面堆装重量限制临界曲线的基本原理并提供了曲线图的实例，这对于缺乏这类船舶资料或计算软件的船舶，具有实用价值。     

恶劣海况下拼装式机库受力和绑扎加强研究

为便于在动员民船上快速加装,某型直升机机库采用集装箱拼装结构。针对恶劣海况下机库的整体稳定性和安全性问题,研究通过采用绑扎的方式进行加强。本文首先分析了组成机库的单个集装箱、机库侧壁等组件在非绑扎和绑扎状态下的受力与变形;然后输入恶劣海况下的极端工况数据进行计算,结果显示机库部件受力和变形将对机库安全造成不利影响,应进行绑扎加强;最后通过绑扎后机库整体稳定性和抗侧力计算,结果显示机库整体和侧壁的受力可完全被绑扎杆拉力抵消,绑扎加强能够提高机库的安全性。     

Prediction of capsizing probability for a ship with trapped water on deck

The authors have already examined a method for evaluating the capsizing probability of a ship in the dead ship condition based on a piecewise linear approximation of the restoring arm. Here, this method is extended to ships with trapped water on deck. This is because the stability of ships having a relatively high bulwark, such as fishing vessels, could substantially deteriorate due to trapped water on deck. First, the mean amount of water trapped on deck was estimated as a function of the significant wave height and the mean wave period using a model experiment in irregular beam seas. Second, the restoring arm curve with trapped water on deck was calculated hydrostatically and then approximated with a piecewise linear curve. Third, the roll angle was estimated using a nonlinear and uncoupled equation of absolute roll angle under stochastic wave and wind exciting moments. The short-term and long-term capsizing probabilities were calculated for a fishing vessel operating off Kyushu. Numerical results quantitatively demonstrated that the effect on capsizing probability of trapped water on deck cannot be ignored when accurately evaluating the stability of fishing vessels.     

Investigations of vehicle securing without lashings for Ro-Ro ships

To reduce the area on deck occupied by each car and the labour and time required for lashing and unlashing cars, it has been proposed by the author that in some conditions, cars on decks could be transported without lashing. To evaluate cargo securing based on this “lashing-free” concept, computational code was developed to calculate the vehicle–deck interactions for various ship motions. The code was structured by incorporating a vehicle model into a piece of ship motion calculation code. A series of time-domain simulations were conducted to evaluate vehicle securing. It was found that for a target ship consisting of a 6000-unit Ro-Ro vessel, vehicle securing is mainly influenced by the ship's rolling motions and is highly dependent on the wave height and loading conditions. It was suggested from the analysis that vehicles could be secured without being lashed in a large area of the ship in specific weather conditions and on some routes with less adverse sea states. However, it is still suggested that conventional lashing holes should be constructed on the deck because in severe sea states the cars will still need to be lashed. The limitations of the current investigations are also presented. The relevant research work was carried out at the Division of Ship Design and Engineering, Department of Shipping and Marine Technology, Chalmers University of Technology.     

“明州22”号船风帆骨架强度有限元分析

对集装箱船用风帆结构力状况进行了分析，用不同梁单元构造了风帆典型结构的有限元模型。通过对各应力分量进行分析，拽出了风帆结构的总体强度以及是易破坏的危险区域。     

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.     

叠船运输方式下的半潜船耐波性分析

以叠船运输方式下的半潜船为研究对象,采用CATIA软件进行三维建模。基于AQWA软件计算在规则波中不同浪向、不同航速和不同吃水下的响应幅值算子(Response Amplitude Operator, RAO),分析在不规则波中不同海况条件下货物绑扎设计关键点的加速度变化,发现浪向、航速和吃水等因素对RAO的影响规律。研究结果可为叠船运输方式下的半潜船安全运输提供运动预报,为货物绑扎设计提供依据。     

基于CATIA V6的绑扎桥三维设计方法

在集装箱船逐步大型化的大趋势下,对绑扎桥的设计要求逐渐凸显。本文基于CATIA V6软件平台,提出了一套绑扎桥三维设计方法。综合考虑了绑扎桥的实际设计需求以及三维模型化的技术难点,通过利用参数化定义,EKL二次开发手段,以及CATIA V6中片体模型转实体模型,片体模型转FEM模型等强大的原生功能有效地解决了快速建模、CAD/CAE一体化、BOM数据与出图信息集成等一系列难题,充分利用了三维技术减少设计流程中的信息孤岛现象,基于高度集成的参数化模型来提高设计响应速度与准确性。最后通过实践案例予以验证并分析了该方法的工程实用价值。     

45000t集装箱滚装船超高导轨架精度控制

45000t集装箱滚装船的货舱区采用特殊的无绑扎、无舱盖设计,并使用最长约30m的超高导轨架结构对集装箱进行装载限位。为顺利安装超高导轨架并满足相关规范的要求,对传统的安装工艺及精度控制进行对比分析,根据超高导轨架特殊的结构形式及相关用途,重新梳理一套安装流程,分阶段加强精度控制。介绍该类型船所采用的超高导轨架的结构形式特点,对导轨架安装难点和精度策划思路进行详细阐述,给出导轨架分段预装工艺,详细描述超高导轨安装时各阶段的精度控制要点。通过吊箱试验验证该策划方案的可行性,结果表明,其在保证生产效率的同时能有效保证超高导轨架的建造精度,可为后续产品提高施工质量及施工效率提供参考。     

弯道航行时集装箱侧翻落水事故防范

对某船弯道航行时船载集装箱侧翻落水事故建立力学分析模型,提出防范该类事故的技术路线为降低集装箱绑绳的拉力和提高其许用负荷,提出了四种改进措施,数据分析表明,综合采取四种改进措施后,可有效避免绑绳崩断所导致的集装箱侧翻落水.     

大型集装箱船绑扎桥结构优化设计

为有效降低大型集装箱船的空船重量,针对绑扎桥结构轻量化设计进行研究。以某14500TEU集装箱船为研究对象,根据船级社规范要求针对结构设计方案进行有限元计算分析,依次从剪力墙布置、立柱设置和局部尺寸优化等三个层次对原始方案进行优化设计。研究结果表明,优化方案在满足船级社规范要求、保证堆重指标的同时有效降低了绑扎桥的结构重量。本文的设计思路和优化方法可以为今后大型集装箱船绑扎桥的结构设计提供一定参考。