新的SOLAS概率破舱稳性及其在MiniCAPE型散货船上的应用研究

根据《1974年国际海上人命安全公约》第Ⅱ-1章新的概率破舱稳性的修正案(简称SOLAS 2009),对江南造船(集团)有限公司自主研发的115000吨MiniCAPE型散货船进行概率破舱稳性的计算研究.重点探讨了新、旧规范的差异及新规范对大型散货船概率破舱稳性计算的影响.     

散货船破舱稳性计算及安全措施

根据SOLAS修正案“散货船的安全措施”及“货船分舱和破舱稳性”的各项条款的要求，计算并校核了五条散货船第一货舱破损进水后的平衡状态和船舶分舱指数，分析了不满足要求的原因，探讨了具体的改造措施，提出了新船设计的建议。     

基于协调版共同结构规范的18万吨散货船结构设计

根据IACS2014年1月推出的CSR-H,对目前CSDC设计的18万吨散货船进行符合CSR-H设计。分别运用美国船级社的CA Stage 1程序和CSR-H Bulk Check Stage 2程序进行规范计算和有限元计算,给出满足CSR-H要求的货舱区结构重量对于CSR规范的增加量。主要内容如下：一、比较CSR-H与CSR对散货船要求的差异,分析CSR-H对散货船设计的影响。二、对货舱区各个横剖面进行规范计算,研究CSR-H对板材和型材尺寸的新要求,分析各结构部位与满足CSR船型结构存在差异的原因。三、应用直接计算法对全船货舱区进行屈服和屈曲强度评估,比较基于CSR-H要求的计算结果与CSR要求结构尺寸存在的差异。     

散货船国际安全措施

本文简要分析了九十年代以来散货船海损事故及原因，回顾了几年来ＩＭＯ和Ｉ－ＡＣＳ寻求散货船安全措施的历程和合作，并提出还需解决的遗留问题及有关建议。     

散货船特殊要求的适用及检查探讨

文中通过梳理国际公约中对散货船特殊要求的修正情况,明确了以散装形式装运干散货的船舶如何满足SOLAS公约中对散货船的特殊要求,并结合笔者的检查经验,总结归纳了散货船的检查要点。     

Collapse strength of hatch cover of bulk carrier subjected to lateral pressure load

A series of elastoplastic large deflection FEM analyses has been performed on hatch covers of bulk carriers subjected to lateral load. Two types of hatch covers are considered which are the folding type and the side-sliding type. For the folding-type cover, one size is considered which is for Handy size bulk carrier, whilst for the side-sliding-type cover, two sizes are considered which are for Panamax and Cape size bulk carriers. For each type, two hatch covers are selected which are designed in accordance with the old ICLL rule and new IACS rule, respectively. Calculated collapse strengths are compared with individual design loads, and a strength assessment is performed. On the basis of collapse behaviour observed in FEM analyses, a simple method is proposed to evaluate the collapse strength of a hatch cover subjected to lateral load. It is confirmed that the collapse strength is accurately predicted by the proposed method.     

深水钻井船波浪载荷预报

以两艘钻井船为例,分别计算其波浪载荷传递函数和波浪载荷长期预报值,将计算结果与规范计算值比较,且对其中一艘钻井船计算其不考虑月池开孔时的波浪载荷预报,试图找出钻井船与常规船型的差异,为结构设计人员在钻井船设计方面提供一定的借鉴。     

“SOLAS第Ⅱ-1章破舱稳性新旧规则”对比分析

“SOLAS2009”对原“SOLAS第Ⅱ-1章”的内容作了重大修改。文章以货船为例,对修订后的SOLAS第Ⅱ-1章中“统一的破舱稳性规则”与原有规则归纳对比和计算分析,指出了基于实际计算的关键要素,可为船舶总体设计提供参考。     

Reliability analysis of a bulk carrier in ultimate limit state under combined global and local loads in the hogging and alternate hold loading condition

The alternate hold still-water loading in hogging combined with wave loading is critical for the safe design of bulk carriers. The ultimate longitudinal strength of the hull girder of bulk carriers in this condition has been found to be considerably reduced by the action of local lateral pressure loads. In the present paper, an interaction equation based on the ultimate hull girder strength assessment obtained by nonlinear finite element analyses is adopted to consider the relationship between ultimate longitudinal bending capacity and average external sea pressure over the bottom. This interaction equation is used as the basis for the failure function. The annual probability of failure is obtained by FORM analysis considering two typical load cases, namely, pure longitudinal hogging bending moment and combined global hogging bending moment and local lateral pressure loads. The effect of heavy weather avoidance on the failure probability is evaluated. The results show that the local lateral pressure has a significant influence on the annual probability of failure of bulk carriers in the hogging and alternate hold loading condition.     

Practical estimation method of the design loads for primary structural members of bulk carriers

Various design loads used in the strength evaluation of ship structures have been introduced currently by classification societies. As most of these design loads have been determined as standard loads for the sake of convenience, the relationships between the design loads and the sea states actually encountered by ships seem to be weak. Accordingly, it may be difficult to refer and utilize them as fundamental design concepts for ship designers or as operational guidelines for ship operators. In view of this background, various efforts (Trans. West-Jpn. Soc. Nav. Archi. 89 (1995) 191; 93 (1997) 121; Jap Shipbuild. Mar. Eng. 2 (1967) 13; Proceedings of the 18th International Conference on Offshore Mechanics and Arctic Engineering 1999; Mar. Struct. 13 (2000) 495; J. Ship. Res. 45 (2001) 228; J. Mar. Sci. Technol. 6 (2002) 122; J. Soc. Nav. Archi. Jpn. 186 (1999) 319; Technical guide regarding the strength evaluation of hull structures, 1999; Proceedings of the 14th International Conference on Offshore Mechanics and Arctic Engineering, 1995; Mar. Struct. 10 (1997) 611; Proceedings of the Eighth International Symposium on Practical Design of Ships and Other Floating Structures, Shanghai, Vol. 2, China, 2001, p. 1089; Mar. Struct. 12 (1999) 171; Mar. Struct. 4 (1991) 295) have been made in recent years for developing estimation methods of the design sea states in a rational manner. Furthermore, for more practical purposes, the authors have developed practical estimation methods of the design sea states, the design regular waves and the design loads having transparent and consistent backgrounds to the actual loads acting on primary structural members of tankers (Mar. Struct. 16 (2003) 275).In this paper, it is firstly confirmed that the proposed methods for tanker structures can also be applied to the primary structural members of bulk carriers. Furthermore, the necessary modifications are carried out considering the specific structural types and loading conditions of bulk carriers in order to improve the estimating accuracy of the proposed design loads. Finally, comparisons between the results obtained by the structural analysis of a hold model applying the proposed design loads and long-term values of stresses by the most advanced direct structural analyses for different loading conditions are introduced and discussed in detail.     

Effect of pitting corrosion on the ultimate strength of steel plates subjected to in-plane compression and bending

Corrosion pits with a circular cone shape are typically observed on coated hold frames of aged bulk carriers which carry exclusively coal and iron ore. In order to ensure the safety of these types of bulk carrier, it is necessary to understand the effect of pitting corrosion on the local strength of hold frames. In order to investigate this effect, a series of nonlinear finite-element (FE) analyses has been performed with pitted plates subjected to in-plane compressive loads and bending moments. It has been shown that the ultimate compression load or bending moment of pitted plates is smaller than that of uniformly corroded plates in terms of average thickness loss, and that predictions of the ultimate strength using the average thickness loss at the minimum cross section would be conservative. In order to establish a method of evaluating strength reduction due to pitting corrosion, it is important to identify the failure mode that would be most detrimentally affected by pitting corrosion. It was found that the reduction of the ultimate compressive load or bending moment due to pitting corrosion is smaller than that of the tensile strength in terms of equivalent thickness.     

一种精细化的多项目管理方法

本文结合我国目前中小科技企业和应用开发型科研单位的管理现状,着力于提升生产管理的效率和水平,针对管理中新出现的问题,如多项目管理被动、可变性适应力弱等,提出了一种新的适应生产管理的任务量曲线应用方法.应用任务量曲线可以实现在生产管理中,多项目综合计划科学合理安排,从而大幅提升生产管理的精细化水平.     

Tanker safety: Regulatory change

There are many regulatory changes being imposed on tanker operators of new and existing ships. This paper provides a brief on the main changes and their practical impact on design and operation i.e. the significant recent and upcoming revisions to IMO MARPOL Annexes I, II and VI, SOLAS and other regulations and the IACS Common Structural Rules.     

Effect of pitting corrosion on local strength of hold frames of bulk carriers (2nd Report)—Lateral-distortional buckling and local face buckling

Pitting corrosion is typical corrosion observed on coated hold frames of bulk carriers which exclusively carry coal and iron ore. In order to secure the safety of these types of bulk carriers, it is important to understand the effect of pitting corrosion on local strength of hold frames.

In order to investigate this effect, a series of 4- and 3-point bend tests on structural models which consist of web, shell and face plates has been carried out. Artificial pitting was created on the web plate to simulate pitting. In the 4-point bend tests, two equal concentrated loads have been applied vertically at the one-third points of simply supported models so that compression load due to bending would act on the face plate. In this testing condition, lateral-distortional buckling occurred before reaching the ultimate strength and local buckling of the face plate was observed after reaching the ultimate strength. The effect of web plate pitting on the lateral-distortional buckling strength was found to be small but the ultimate strength decreases with increase in the degree of pitting intensity. In the 3-point bend tests, concentrated load has been applied vertically at the center of simply supported models so that compression load due to bending would act on the face plate. In this testing condition, local face buckling occurred just after reaching the ultimate strength. The ultimate strength is found to be decreasing with increase in the degree of pitting intensity.

A series of non-linear FE analyses has been performed to simulate the deformation behavior observed in the tests. It has been revealed that even in the case of randomly distributed pitting corrosion the ultimate strength of the structural models was almost the same as that of the structural models with uniform corrosion corresponding to the average thickness loss.     

自由降落救生艇试验过程探讨

SOLAS公约规定2006年7月1日起建造造的散货船均应配备自由降落式救生艇,其他型船也早于此配备了此型艇.本研究以HH76FC型艇和FH-70型艇架为例,探索研究了自由降落救生艇试验的过程,并运用物理和数学的方法对整个自由抛落的过程进行了分析,为日后其他类似的试验和设计提供借鉴和帮助.     

HCSR：犹抱琵琶半遮面

据悉，IACS近来年倾情打造的协调共同规范（HCSR），又将整体发布时间向后推迟了半年。是何原因使IACS集结了全部人力物力投入的HCSR如此姗姗来迟？HCSR闯重重关HCSR不仅是IACS要完成对工业界许下的将CSR协调一致的承诺，更是为了满足国际海事组织（IMO）GBS审核而全力应对的措施。     

万箱集装箱船典型货舱结构极限承载能力计算

随着世界货运量的需求增加,集装箱船的大型化发展从未停止。近十年内,有2艘大型集装箱船先后在海上遭到极端载荷而丧失结构承载能力以致发生灾难性毁坏,给航运界敲响了警钟。为了避免今后大型集装箱船再次遭遇上述严重事故,保证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针对集装箱船的规范要求进行修改,提高了载荷设计值,并且要求评估典型货舱结构的极限承载能力。本文针对万箱集装箱船典型货舱结构,基于逐步破坏法和有限元法,计算了垂向和水平方向的极限弯矩。结果表明,在初步设计阶段逐步破坏法有着快速高效的优势,但是考虑到载荷变化的多样性和船体结构的复杂性,还是需要应用非线性有限元法进行建模计算,给出最终评估结果。     

11.5万dwt散货船结构设计研究

针对IACS所发布的散货船共同结构规范(CSR),进行Mini-Cape型散货船的结构设计工作。为补偿该船扁平型横剖面的特征对总纵强度的不利影响,在设计前期对分舱进行了优化,控制了设计弯矩。在此基础上,结合CSR要求对结构设计进行了优化,开展了结构设计和强度校核工作,为控制全船空船重量奠定了良好的基础。     

A risk-based first-principles approach to assessing green seas loading on the hatch covers of bulk carriers in extreme weather conditions

This paper aims to present and explain the work undertaken at the SSRC on the Safety of Bulk Carriers in extreme weather conditions over the past 3 years, to draw conclusions deriving there from, concerning key influencing design, operational and environmental parameters and to offer recommendations regarding the rule development process and on the way forward considering research, development and implementation to ship design and operation with the view to improving the safety of these ships cost-effectively. In severe storms, hatch covers of low freeboard vessels such as bulk carriers are the first-line of protection against flooding. Present methods of hatch covers design are still empirical because impact loads due to green seas and structural behaviour due to this type of loads have not been examined, hence not known accurately. The loading due to green seas is implicitly non-linear and, as model test results demonstrated, bulk carriers in extreme conditions are exposed to significant loads, which in some cases exceed current design standards. Since the consequences of hatch cover failure are potentially catastrophic, the risk of this happening should be quantified in probabilistic terms as required by modern safety standards. To this end, the paper aims to propose and implement a methodology for estimating probabilities of deck wetness and impact loads due to green seas as a function of key design and operational parameters.     

CSR-H与CSR强度评估载荷的对比研究

对CSR-H 与CSR用于强度分析的载荷变化进行分析,对各载荷分量的包络值以及应用于等效设计波中的船体梁波浪弯矩、波浪剪力和外部海水压力、加速度等载荷分量的大小进行比较。分析货油舱、干散货舱、压载舱典型位置处的内部压力变化,并对载荷变化可能引起的结构要求变化进行分析和概括。