抬浮力打捞工程船艉轴轴承热力学有限元仿真

以12 000 t抬浮力打捞工程船为例,采用COMSOL Multiphysics有限元分析软件中的热力学模块对艉轴轴承的散热情况进行研究。介绍轴系布置和艉轴管空舱,分析油膜建立情况下的艉轴轴承热平衡和工作压力分布,进行轴系与艉轴管空舱的热力学有限元仿真。仿真结果满足艉轴轴承的相关要求,并在实船试航中得到验证,表明可取消常规的艉轴管冷却水舱。     

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.     

37 500 m3 LEG船液罐吊装精度数字仿真分析

以37500 m³液化乙烯气(Liquefied Ethylene Gas,LEG)船货舱区液罐吊装为研究对象,对液罐吊装前的干涉检查和数据匹配等工作进行梳理,建立一套完整的液罐吊装模拟匹配流程,并对实际吊装过程出现的问题提出解决方案,旨在为后续同类大型液罐的吊装提供参考、积累经验。     

基于粒子群优化反步法的船舶航向控制器设计

考虑到反步法在随机干扰下具有较优的控制效果,利用反步法设计基于Nomoto模型的船舶航向控制器;设计一种基于粒子群优化(Particle Swarm Optimization,PSO)反步法的航向控制器,其能通过优化不确定增益参数来消除部分冗余控制。通过仿真试验比较不同航向控制器的性能。仿真结果表明:粒子群优化反步法航向控制器具有更高的控制精度和更强的鲁棒性。     

12000 t抬浮力打捞工程船电力系统

针对12000t抬浮力打捞工程船,在概括介绍其船型特点的同时,对其电力系统以及在系统设计时需要注意的一些问题进行了详细描述,为同类电力系统设计提供参考.     

乌江思林和沙沱升船机船舶超吃水可行性研究

针对乌江思林、沙沱两座升船机船舶1.6 m吃水控制标准导致载货量偏低的实际问题,开展超吃水船舶进出升船机船厢系统性的实船试验,论证船舶吃水标准提升的可行性。结果表明,船舶出厢为控制性工况,2.0 m吃水船舶正常出厢实测最大下沉量16.46 cm,富余水深大于30 cm;基于实船试验数据改进的下沉量预测公式,将船舶实际下沉量预测精度提高1倍以上;按目前2座升船机运行水位协调机制,上下游水位变化在10 cm以内,船舶最大吃水提升至2.0 m是可行的。建议在运行中按照1.8~2.0 m吃水逐步放宽控制标准。     

铝合金在邮轮主船体结构上的应用分析

基于铝合金与钢结构“等强、等刚、等稳定性”的理论和有限元计算方法的分析,对某邮轮主体结构进行替代等效分析,论证了铝合金结构的安全性、经济性以及可能性,为铝合金在邮轮主船体结构的应用和直接计算方法提供建议和参考。     

Valuation mismatch and shipping q indicator for shipping asset management

ABSTRACT

This paper aims to develop an adaptation of the Tobin Q investment model for the shipping asset management in order to monitor valuation mismatch and bubble pricing of shipping assets. In this circumstance, the market prices of various shipping assets (e.g., Capesize or Panamax dry bulk carriers in different age profiles) are compared to the measured long-term asset value with second-hand ship prices. The mark-to-market prices of shipping assets are led by current market trends and freight rates, while the long-term asset value is estimated by using past data under certain assumptions (mean reversion, trend reversion). The discrepancy between market prices and the long-term nominal value of a shipping asset reflects any mispricing, which in turn sheds light on investment timing and market entry-exit decision.     

Overview of maritime research publications by the late Professor Richard O. Goss

We lost one of the great maritime scholars in 2017—Professor Richard Goss, who is considered one of the founders of maritime economics. He was a pioneer and a most influential leader in establishing the discipline of maritime economics worldwide. This paper revisits his research by examining major issues and assessing his arguments by surveying empirical works that have been conducted after his works in the literature. His economic thoughts are based on laissez-faire, welfare economics, and Marshallian economics. Comparing his arguments with major findings in ensuing research, several research directions are suggested.     

全舰（船）统一姿态基准系统中甲板变形分析

为了研究舰船甲板的变形,此文对甲板结构进行了简化,建立了甲板受力的数学模型。分别在舰船处于中垂和中拱两种状态下,对舰船甲板受横向载荷、总纵弯矩及两者共同作用下的变形进行了计算。