某船舶大功率高压转子建模及模态分析

针对某船舶大功率高压转子的结构特点,对其转子在合理的简化处理基础上,通过UG和ANSYS软件建立其有限元分析模型。通过有限元数值分析软件对转子模型进行模态求解,得到了转子的前五阶固有频率和振型。通过对计算结果的分析验证了转子工作的可靠性,并为高压转子的其它动力学分析提供模型,为进一步船舶机组振动的故障诊断奠定基础。     

多级齿轮传动系统扭振建模及模态分析

通过简化,建立了三级齿轮传动系统扭转振动的动力学模型,建立了实际传动系统的有限元模型,进行了有限元模态分析,从而得出其固有频率及振型,为齿轮传动系统的动力学分析打下了基础.     

某型燃气轮机低压压气机转子模态及动力学分析

采用CAD/CAE综合分析方法,基于实体模型,应用网格划分软件Hypermesh,建立某型燃气轮机低压压气机转子的有限元模型.利用数值仿真软件求解转子的固有频率和弯曲振型、临界转速以及稳态不平衡响应.计算结果表明转子具有良好的整体结构刚度,一阶临界转速安全系数合理.动力学分析结果表明,在压气机的设计及制造工艺中需要对转子第4级的平衡工作以及此处附近转鼓的结构强度给予一定重视.     

海洋平台相似模型设计及模态实验分析

通过理论分析,研究了材料阻尼对相似模型设计及实验数据分析的影响,在此基础上,设计并建造了海洋平台相似模型,并通过多输入单输出的方法对相似模型进行模态实验,得到其固有频率、空间振型、阻尼比等动力学参数。结果表明,材料阻尼对相似模型的几何尺寸没有影响,对模型的固有频率影响不大,可以忽略;但对模型的动力响应影响很大,在实验数据分析中必须加以考虑;为了方便应用,还给出已知阻尼比和阻尼系数时的转换关系。将模态实验数据与仿真分析结果进行对比,二者符合较好,从而验证了相似模型设计与建造的一致性及实验数据的可靠性。     

隐身夹芯复合材料舵振动特性研究

对声隐身夹芯复合材料舵进行壳板和整舵的结构形式设计;应用有限元软件MSC. Patran和MSC.Nastran建立声隐身夹芯复合材料舵和钢质舵模型,进行模态计算,得到夹芯舵和钢质舵干湿模态下的各阶固有频率和振型;与局部壳板小模型的振动模态进行比较,分析两种模型不同的振动规律.比较两种舵结构的模态节线图,分析格舵的弯曲、扭转及耦合振动模态.结果表明:隐身夹芯复合材料舵固有频率低于钢质舵,且振型主要为整体弯曲、扭转振动,壳板局部振动较小.     

敷设粘弹性层舱室的振动特性仿真分析与试验

轮船舱室的减振设计需要对舱室的固有振动特性和响应进行分析.基于AnsysWorkbench对舱室进行模态分析,利用壳单元对舱室进行建模,获得其前20阶的固有频率、振型,并对仿真结果和试验结果进行对比.利用半功率带宽法测出舱室阻尼比,在模态分析基础上对舱室进行谐响应分析,得到位移和频率响应曲线.考虑粘弹性材料频变特性,对...     

基于HyperWorks的船用升降设备模态分析

应用有限元软件HyperWorks,对某船用升降设备进行模态分析,获得了该设备前6阶模态的固有频率、振幅及振型等动力学特性,为进一步动力分析求解提供了参数,并将模态分析结果与发动机激振频率对比,证明了其机械设计较为合理。     

离心通风机降噪设计研究

本文介绍了采用低噪声风机结构和振动模态试验技术相结合的方法研究设计船用低噪声离心通风机,使之达到低噪声的目的。对风机的主要部件,如叶轮、叶片、进风口及风舌间隙,进行了最佳的气动力设计,应用振动模态试验技术,分析风机的振动模态与噪声的相干关系,在风机的机壳内粘贴模态阻尼板,改变了风机的模态,增加了阻尼,从而降低了风机振动产生的噪声。     

水润滑橡胶艉轴承模态分析研究

采用有限元计算与试验模态相结合的方法进行两种模态频率和振型分析,以及模态置信度的计算与对比.结果表明,在计算模态与试验模态相似对应的模态振型中,两者的板条振型弯曲趋势相似;计算模态与试验模态数值接近,两者相关性良好,有限元结构模型可以反映实际结构模型.     

永磁同步电动机结构的模态研究

论文先简要介绍模态分析理论,再运用机电类比的方法推导定子固有频率的计算方法,并用ANSYS软件对电机定子建立的三维有限元模型进行模态分析,计算出它们的固有频率及其振型,避免和电磁力的频率及次数发生共振,从而降低永磁同步电动机的电磁振动和噪声.     

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

正~~     

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;     

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。     

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）.     

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.     

桥梁防撞设施物理模型试验

物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。     

印尼某电厂码头水工建筑物设计

印尼某电厂项目码头水工建筑物包括码头、防波堤和护岸等主要组成部分。在该项目水工建筑物的设计过程中,综合考虑当地的自然条件、施工能力和材料来源等因素,不断优化结构选型和结构断面。根据不同使用要求,护岸分别采用直立式和斜坡式2种结构型式,推荐的设计方案节省投资、施工方便,可供同类工程设计参考。     

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.     

开放式数据挖掘系统模型

目前国内已经出现了少量的数据挖掘相关产品。国内数据挖掘软件无论从数量还是质量上比较，都与国外软件存在着较大的差距。随着数据仓库技术的普及，数据挖掘应用的需求越来越强烈，如何缩短这种差距，研发数据挖掘软件产品成为国内业界的一个重要问题。通过引用目前国际通用数据挖掘标准技术来构建开放式的数据挖掘系统模型，该系统模型从可扩展性、可重用性、易用性等方面得到了加强。