EH47高强度厚钢板角焊缝裂纹修补工艺研究

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。     

20000TEU超大型集装箱船舶时代与港口面临的挑战

介绍超大型集装箱船舶的现状和发展趋势,分析当今的世界航运市场,提出了港口在新航运时期的应对措施。     

Assessment of investment decision in the dry bulk shipping market based on real options thinking and the shipping cycle perspective

As the dry bulk shipping market seems to have been stuck in a trough period for a long time, investors need to pay more attention to their investment strategies to survive during this period. This study aimed to find a suitable model to assess dry bulk ship investment decisions in the tough and peak periods based on real options theories. Two options, involving an abandonment option and a deferrable option, were used to define investors’ responses to the uncertainty in investment processes such as stopping or selling vessels. The option valuation was solved by using a binomial valuation model, due to data limitations. In accordance with shipping cycle theories, different volatility parameters for the tough and peak periods were calculated using a generalized autoregressive conditional heteroskedasticity (GARCH) model. The application of the real options model to a case study involving secondhand ship trading indicated its viability. According to the results of the case study, the new model has advantages over the traditional net present value (NPV) method in uncertain investment environments. Thus, the results demonstrate that the real options model is a more suitable method for use in the current dry bulk shipping market.     

长江干线集装箱吞吐量分析预测

港口集装箱吞吐量是进行港口规划和加强港口建设的依据,预测长江干线主要港口企业集装箱吞吐量对促进长江干线水域经济发展发挥了重要作用。以长江干线主要港口企业集装箱吞吐量为基础,分析二次指数平滑法、灰色模型预测法和BP-GA算法的原理,分别建立三种相应的预测模型并比较预测结果及精度。结果表明BP-GA模型能更加准确预测集装箱吞吐量在时间序列上的变化趋势,预测拟合度最佳。最后以该模型预测分析2021年1月至12月的长江干线主要港口企业集装箱吞吐量,为未来长江航运发展提供参考。     

世界集装箱海运网络社团结构研究

从复杂网络的角度,探讨世界集装箱海运网络的结构特性,并提出了海运区块划分的新视角. 根据最新数据,验证海运网络的小世界和无标度特征. 基于模块度理论及分辨率理念,将网络进一步细分形成特征各异的三大海运区域和八大区块. 研究结论为：世界集装箱海运网络度分布符合幂为-8.96 的幂律分布;海运网络分布受海峡、运河等自然地理空间限制,具有显著的地理特征;各海运区块活跃程度不一,可以用航线密度为基础的加权平均度变化衡量;海运区块同样具有小世界和无标度特性,且不受网络规模影响;区域枢纽港的聚类系数普遍趋近0.2,为识别大型中转枢纽港提供依据.     

多箱型内河集装箱船舶配载决策研究

内河集装箱运输具有其独特性,船舶配载时更强调船舶舱容利用率.考虑特殊箱型影响,以最小化堆栈占用数量为目标,构建内河集装箱船舶配载决策的整数规划模型.为实现快速寻优,设计包含构造部分和优化部分的启发式算法求解.算法中,构造部分基于启发式规则快速构造初始解,优化部分基于邻域搜索策略实现初始解优化.算例研究表明,模型可实现内河集装箱船舶配载决策问题的有效求解,但随着算例规模增加所需求解时间大幅增加.与模型精确求解相比,启发式算法在求解时间方面表现要远优于模型,可在0.25 s内实现所有算例的高效求解,为内河集装箱船舶实际配载决策提供一定参考.     

考虑碳排放政策的港航企业减排策略研究

考虑政府采取碳税或碳排放权交易机制两种碳排放政策，基于供应链视角，构建港口与航运企业减排博弈模型，系统分析港航企业减排策略选择和政府碳排放政策选择问题。结果表明：当航运企业减排成本小于港口协助减排成本时，港航企业选择分散决策减排力度最优；反之，选择集中决策减排力度最优。在集中决策情形下，港航供应链减排力度与航运企业减排成本和港口协助减排成本成反比，和市场容量成正比；在分散决策情形下，港口协助减排成本不会影响港航供应链减排力度。在碳定价较低时，港航企业选择分散决策定价最优，选择集中决策利润最优；在碳定价较高时，则相反。无论政府采取何种碳排放政策，港航企业选择集中决策并且政府对港口减排进行补贴，会使港航供应链整体利润与减排力度同时达到最优。在未来碳定价大幅提升的情况下，政府采取碳排放权交易机制推动港航企业减排效果更好。     

2750TEU集装箱船局部振动评估

针对2 750 TEU集装箱船,在船体总振动评估的基础上,采用经验公式及有限元法,对液舱及上层建筑的局部振动进行详细评估,并根据不同区域的计算结果采取相应的改进措施.     

Cargo ship aft panel stresses prediction by deconvolution

This article introduces novel extreme value prediction method that can be used for a variety of offshore engineering applications. First, to demonstrate the novel method, fictitious data from a non-linear Duffing oscillator and measured wave heights were used as examples. The second incident included a container ship that experienced significant deck panel strains while traveling across the Atlantic Ocean in bad weather. The main concern for cargo ship transportation is potential loss of container owing to violent movements. It is challenging to model such a situation because waves and ship motions are both non-stationary and complicatedly nonlinear. Extreme motions greatly increase the role of nonlinearities, activating effects of second and higher order.Furthermore, due to the scaling and the choice of sea state, laboratory testing may also be called into doubt. Therefore, data collected from actual ships during difficult weather voyages offers a special perspective on the statistics of ship motions.This paper aims to highlight an alternative method of extrapolation that is based on intrinsic properties of the data set itself and does not assume any extrapolation functional class. Extreme value predictions typically originate from certain statistical distribution functional classes to fit the data and then extrapolate. Engineering design can make use of the unique extrapolation method that has been proposed. The proposed method's forecast accuracy has been verified in comparison to the Averaged Conditional Exceedance Rate (ACER) extrapolation method.     

政府环境规制下港航系统减排演化博弈研究

针对碳达峰目标下我国港航系统的减排问题，通过构建地方政府、港口和航运公司三方主体参与的港航系统环境规制演化博弈模型，系统分析三方主体的策略选择过程与整体演化稳定性，阐明港航系统内各主体演化趋势的驱动机理。并通过数值仿真分析，讨论三方主体初始策略和地方政府不同奖惩监管机制下港航系统的策略选择。研究结果表明，地方政府主动监管策略的选择与港口和航运公司的低积极减排意愿有关；港口和航运公司积极减排策略的演化速率与彼此的意愿成正比；地方政府在静态奖惩监管机制下，对惩罚强度的调整不影响港口和航运公司的积极减排策略，但低补贴强度会导致两者的消极减排；静态监管机制下，地方政府仅有(高补贴，无惩罚)的单一策略可以使港口和航运公司达成(积极减排、积极减排)的演化均衡；动态监管机制下，地方政府采取(低动态补贴，高静态惩罚)的混合监管策略能够以低成本实现港航系统积极减排策略的演化均衡。