船舶阻抗失配基座对平面弯曲波传递的阻抑特性

研究了船舶阻抗失配基座对平面弯曲波传递的阻抑特性.基于波动理论,根据不均质结构中波型转换、阻抗特性,推导并给出了振动波入射不同连接形式的船舶基座结构的透声系数及隔声量公式,归纳了隔振性能随基座板架厚度比及频率变化规律,讨论了基座连接结构处板架固定方式对隔振性能的影响.在理论分析基础上,构造含阻振质量的阻抗失配基座.数值结果表明阻抗失配基座显著增大了基座的输入机械阻抗,加剧了振动波在船体板架中的波形转换、散射和反射,显著提高了舰船基座结构的隔振效果.     

水下结构物长基座拓扑与尺寸优化设计

[目的]基座结构的阻抗值及不同加载点间的阻抗均匀性会影响水下结构物辐射噪声。[方法]以一典型水下结构物长基座结构为研究对象,将基座腹板单元密度作为设计变量,提出以提高基座阻抗均匀性为目标的拓扑优化数学模型,并根据优化结果提出有效的腹板开孔形式。在此基础上,以基座各板厚作为设计变量,同时将基座的阻抗值及阻抗均匀性作为目标,建立基于宽容排序法的多目标尺寸优化数学模型,获得基座面板、腹板和肘板板厚优化方案。[结果]拓扑结果表明,基座腹板上并不以相同的模式开孔,且腹板开孔中心与其几何中心不同。尺寸优化结果表明,改变基座面板、腹板以及肘板板厚的搭配,可使案例阻抗离散度最大值减小9.37%,同时基座重量降低33.31%,且加载点阻抗最小值基本不变。[结论]为了提高不同加载点间的阻抗均匀性,不宜在基座腹板上以相同的模式开孔;为了兼顾阻抗均匀性和阻抗值,基座各构件不同区域板厚可不相同。研究结果可为水下结构物基座优化设计提供参考。     

典型舰船基座机械阻抗特性参数化快速分析平台开发

基于阻抗分析理论及基座机械阻抗有限元分析方法,开发典型舰船基座机械阻抗特性参数化快速分析平台,对典型舰船基座进行参数化建模并进行有限元分析,快速得到阻抗曲线。分析各结构参数对机械阻抗的影响,为舰船基座设计和改进提供借鉴。     

典型船舶悬臂基座阻抗特性研究

基于阻抗分法探索悬臂型基座的机械阻抗特性,借助有限元软件数值分析典型船体悬臂型基座的阻抗特性,以及基座各结构参数对其机械阻抗的影响规律;在此基础上,基于阻抗失配原理开展了悬臂型基座结构参数优化研究,最终形成一套较准确的船体基座阻抗分析方法,且具有较好的工程应用价值。     

某柴油机基座结构抗冲击计算

利用ANSYS软件建立了某舰船柴油机基座的有限元模型，参照德国军标BV043／85及其他文献所提供的设备冲击谱公式，计算该柴油机基座应承受的垂向冲击载荷，用时间历程法对该柴油机基座进行了抗冲击计算。讨论设备刚性安装和设备弹性安装对基座抗冲击性能，在设备刚性安装的条件下，讨论了基座面板及纵向腹板厚度对基座抗冲击能力的影响。在设备带隔振器安装的情况下，研究隔振器刚度对基座抗冲击应力的变化情况。结果表明，在设备刚性安装的条件下，基座面板厚度对基座整体的抗冲击强度有重要的影响，而设备带隔振器安装显著降低基座在冲击状态下的应力。计算结果为舰船设备基座抗冲击设计打下了基础。     

基于阻抗失配原理的潜艇隔振基座结构设计

研究了潜艇阻抗失配基座对平面弯曲波传递的阻抑特性。基于波动理论,根据不均质结构中波型转换、阻抗特性,推导并给出了弯曲波在潜艇基座结构的透声系数及隔声量公式。在理论分析基础上,基于阻抗失配原理,对某典型基座结构进行隔振设计。数值结果表明阻抗失配基座加剧了振动波在基座中的波形转换、散射和反射。     

舰船基座设计研究

探讨了舰船基座的一般设计准则，介绍了一些典型舰船的基座设计，分析研究了舰船基座的计算设计方法和舰船基座的试验研究方法，提出了舰船基座设计的一般步骤。     

刚性阻振质量在舰船基座设计中的应用研究

基于阻抗失配原理,分析刚性阻振质量阻隔振动波传递的特性,提出在舰船弹性基座中引入刚性减振器．即在舰船基座与船体结构连接部位布设刚性阻振质量．并利用有限元法对基座舱段耐压壳体及基座板结构的振动传递特性进行数值仿真研究。研究结果表明：对于中高频结构噪声,刚性阻振质量能有效降低基座舱段耐压壳体的振动及声辐射,而对于低频结构噪声,阻振质量的减振效果不明显,甚至没有减振效果。这对刚性阻振技术在实艇减振降噪中的应用具有重要的参考意义。     

舰船复合阻振基座的减振特性研究与实验

舰船设备的振动影响了舰船的安全航行和船员的日常生活。本文针对设备基座的减振问题,进行基座的减振特性研究和实验。在介绍基座减振系统和基座优化设计原理的基础上,对复合基座减振进行减振特性研究,提出基座的减振评价指标,并设计实验方案,验证复合基座的减振特性。实验表明,复合阻振基座可极大提升基座结构的减振效果。     

基座设计对隔振效果的影响分析与优化方法研究

本文详细探讨了基座设计对隔振效果影响,并提出在不改变基座结构形式和保持总质量基本不变等前提下,通过优化基座结构变量提高基座首阶弹性频率以提高基座阻抗的方法。利用提出的方法进行某柴油发电机组浮筏隔振装置的实船基座优化实例分析和验证,结果表明,所提出的基座优化方法可以有效提高基座的弹性模态频率,从而达到提高基座阻抗和降低基座振级的目的,对工程应用中提高隔振装置性能具有较好的参考意义。     

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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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.     

某海港码头的撞损修复

依据码头撞击受损区域调查检测结果,对受损构件提出合理的修复方案,为码头的安全运行提供保障。