某船用风力发电机叶片降噪设计

为降低风力发电机叶片噪声,探索从形貌优化到降低风叶噪声的解决方案。根据薄壁结构高刚度形貌优化以提高某阶模态频率为优化目标的特点,通过对风叶结构模态分析,为形貌优化确定合适的目标模态。以风叶几何形状作为设计变量,体积作为约束函数,第一阶固有频率作为目标函数,对风叶结构进行了形貌优化。优化结果表明:改进后风叶第一阶固有频率值由42.3 Hz提高到57.6 Hz,提高了36.2%。在相同的激励下,优化得出的结构具有更多的振动衰减时间,从而达到减少振动以及噪音的目的。     

基于形貌优化的船用球鼻高刚度设计

为提高某船用球鼻结构刚度,提高船舶在特殊航行环境的航行安全性,建立球鼻结构有限元模型。通过对球鼻结构进行模态分析,为形貌优化选择合适的目标函数。以节点位移为设计变量,第一阶固有频率为目标函数,对球鼻包板以及筋板结构分别进行形貌优化。结果表明:筋板结构在形貌优化后,结构第一阶固有频率由6 Hz提高到25 Hz,提高4.2倍,屈服极限提高2.3倍,起到了较好的形貌优化效果,对球鼻结构刚度改善提供设计参考。     

基于形貌优化的舰载电子机柜高刚度优化

由于舰船在运动或者作战时,舰载电子设备会因为振动出现故障,最终导致舰载武器无法工作等问题。通过对舰载电子机柜进行模态分析,基于形貌优化而对舰载电子机柜的刚度进行优化。该优化设计以节点位移为变量,选择第一阶的固有频率为形貌优化的目标函数,对舰载电子机柜做高刚度优化。结果表明:舰载电子机柜在用该方法进行形貌优化之后,舰载电子机柜的刚度明显增强,抗振性能得到显著提高,因而舰载武器系统也能更加可靠。     

DOE技术在起重臂优化设计中的应用

为提高某船用起重机起重臂结构刚度,减小其最大应力以及结构质量,首先对各变量进行灵敏度计算,去除对目标函数不灵敏的设计变量,以提高后续计算效率。基于DOE试验设计理论及有限元法构建优化问题的近似模型,借助拉丁采样对该近似模型拟合精度进行检验。基于遗传优化算法(GA)对该近似模型进行优化。优化结果表明:刚度提高9.4%,最大应力值减小21.4%,结构质量减轻9.3%。     

船艉结构静动态多目标优化设计

建立用于船体结构静动力学性能一体化设计优化的2种多目标优化模型:基于多目标遗传算法的多目标优化模型和基于多学科优化技术的多目标协同优化模型。模型均使用矩阵描述由板材厚度和骨材型号构成的离散设计变量集,以结构质量最小化和最大加速度最小化组成多目标函数。以某集装箱船艉部结构为例,对其进行了结构静力学、动力特性和动力响应的计算分析与优化设计。优化后的结构不仅具有更轻的质量、更低的振动水平,而且具有更高的固有频率储备,同时仍满足强度和刚度要求。     

典型船舶板架拓扑与形状优化设计

以典型板架结构(船底板架和上层建筑板架)为研究对象,探讨结构拓扑与形状优化设计方法在船舶设计中的应用。对船底板架结构进行形状和尺寸优化(优化目标是指定应力约束条件下结构重量最小),优化后的结构重量减少了15.82%。为改善舱室顶部空间布局,提高舱室顶部板架结构的固有频率,对上层建筑板架进行拓扑优化,寻求材料最优分布,并在对其进行静力分析和模态分析的基础上,以体积百分比为约束条件,以板架固有频率为目标函数,得到拓扑优化后的结构型式,新结构型式使材料分布更加合理,有利于舱室顶部管道和电缆等的铺设。研究表明,在目前的板架结构设计中,可广泛应用结构拓扑与形状优化设计技术。     

船身截面结构优化设计

合理的船舶截面设计方案是提高船舶结构设计质量以及航行安全性的重要途径,为了提高船舶结构截面刚度,本文将有限元法与变密度理论相结合,将整个船身截面作为设计区域。以结构密度作为设计变量,最小化结构柔度作为设计目标函数,对船身截面进行优化设计。本文优化得出的船身截面对原船身结构改动不大,同时具有较好的结构加工工艺性,可为船舶结构刚度设计提供参考。     

V型无压载水油船货舱中横剖面拓扑优化

为了优化V型无压载水油船的中横剖面结构，得到更加合理的结构型式，利用变密度法对其进行拓扑优化。选择合适的优化设计区域，以分段重量为约束条件，同时考虑实际生产建造工艺特点，以柔度值最小（即刚度最大化）作为目标函数建立拓扑优化数学模型。同时分析确定优化设计区域初始厚度不同对优化设计的影响，得到载荷的最佳传递路径。最后参考拓扑优化的结果得出新的强框架型式。结果表明，优化后的刚度较之前提高了6.8%，是更加合理的结构型式。对V型船中横剖面进行拓扑优化可在质量不增加的前提下提高其结构性能。     

基于ANSYS大型矿砂船舱口盖的模态分析

基于ANSYSWorkbench建立大型矿砂船舱口盖三维模型,分析计算了舱口盖固有频率和固有振型,计算结果表明船体的激振频率在舱口盖固有频率范围内,因而在其结构设计时需要考虑共振问题。随着振动阶次升高,舱口盖的振动逐渐由整体振动转变为局部振动,刚度越小、振动越剧烈。模态振型分析可为舱口盖结构优化和破坏部位预测提供计算依据,更为船体设计减振措施提供理论指导。     

某船用齿轮结构拓扑优化设计

为提高某船用齿轮结构材料利用率实现其轻量化设计,将拓扑优化技术应用于齿轮结构优化设计。将齿轮截面作为研究对象,将其简化为一平面有限元问题。以齿轮单元密度作为设计变量,最大化齿轮结构刚度为目标函数,轮辐部分优化前后体积比作为约束,对其进行拓扑优化。研究不同轮辐数量、不同体积比情况下齿轮的结构传力路径。结果表明:轮辐部分体积比在0.4~0.6范围时,结构具有较好的刚度,并且加工工艺性优良。本文对于齿轮轮辐部分的拓扑优化结果为实际工程设计提供了指导。     

Errata

正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.     

Journal of Marine Science and Application 2014 Sum. Contents

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第34届海洋、离岸及极地工程国际会议(英文)

正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support;     

33rd International Conference on Ocean,Offshore and Arctic Engineering （OMAE2014）

正San Francisco,California,June 8-13,2014.OMAE 2014 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to:·meet and present advances in technology and its scientific support;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field.     

联合作战计划和执行系统

全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划：时间不限的精密预案计划生成作战计划、方案计划或职能计划；时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础，加速应付危机的能力。     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

The 11th International Conference on Hydrodynamics (ICHD 2014)

正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014.     

第十二届深水操作会议和展览会(英文)

正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas.     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.