含分层损伤复合材料层合板频率响应函数分析

振动分析中含分层损伤复合材料层合板的动力特性是非常重要的，本文主要研究含分层损伤层合板的频率响应函数（FRFs)。首先，建立分层模型和基于FOSD理论的有限元层合板单元，为保证分析模型中避免出现上子板与下子板间的脱离或嵌入，引入了16节点虚拟界面罚单元，其次，根据Adams应变理论，由层合板SDC推导出相应结构振动的模态阻尼；最后，对0%-80%不同分层大小层合板的分析计算结果，讨论了不同分层大小对受损结构的固有频率，SDC和FRFs的影响，本研究不仅有助深入理解含分层复合材料层合板的动力特性，而且可发展用来预报复合材料层合板分层损伤的程度。     

复合材料加筋夹层板动力学固有特性影响因素分析

以复合材料加筋夹层板为研究对象,基于有限元分析,对不同加筋结构方案、加强筋不同宽高比以及不同加强筋芯材对其固有振动特性的影响规律进行了研究。在总重量相当条件下,对比分析了一字型、十字型、卄字型及井字形等四种不同加筋结构方案夹层板的静刚度特性及固有振动特性;以一字型加筋板为研究对象,以加强筋横截面面积为优化约束条件,研究了不同宽高比加强筋对加筋板固有振动频率的影响;对比探讨了一字型加筋板中加强筋芯材弹性模量的变化对结构固有振动特性的影响规律。结果表明：适当选择加筋形式、加强筋宽高比以及加强筋芯材能够有效提高复合材料加筋夹层板的静刚度特性及固有振动特性,为复合材料夹层板的工程应用与改进提供了参考。     

船上含敷料板与加筋结构的固有振动特性研究

本文对含敷料板的低阶模态振动特性进行了研究,将敷料与基板处理为层合板模型,采用基于Mindlin假设的4节点板单元对含敷料结构进行数值模拟,得到系统固有振动特性.为了研究敷料结构系统固有频率的合适计算方法,构造了不同基板厚度和不同敷料厚度,分别采用层合模型和敷料层等效质量的简化方法进行了结果对比.在相应计算例题中,对3种基板厚度和5种敷料层厚度共计15个敷料铺层试件进行了振动测量,并与数值模拟结果进行对比.针对不同铺设厚度的敷料板与加筋板,分别采用敷料质量等效模型和层合板模型,给出了不同计算模型的振动特性计算误差,为工程上选择敷料层振动特征计算方法提供了依据.     

一种复合材料加筋夹芯板弯曲正应力工程计算方法

复合材料加筋夹芯板作为复合材料基本板架结构力学性能分析单元,是由夹芯板和加强筋组成,其蒙皮由不同厚度、不同材料和一定铺设角度的单层板叠合而成。利用材料力学理论和经典复合材料层合板理论,将蒙皮等效成正交各向异性层合板,推导一般情况下的复合材料加筋夹芯板中性轴位置控制方程,并采用等效截面方法,将加筋夹芯板截面等效成单一材料的组合截面,提出复合材料加筋夹芯板弯曲正应力的工程计算公式。复合材料加筋夹芯板各部分的最大弯曲正应力由模量比和距中性轴位置共同决定。本文提出的加筋夹芯板弯曲正应力工程计算方法,与有限元计算结果十分接近,主要弯曲正应力计算值与有限元值误差不超过10%,可以满足工程上的计算要求。此公式形式上和各向同性材料弯曲正应力的计算公式一致,给掌握复合材料板架结构应力水平带来方便。     

线激励下船舶混合构型加筋板的振动特性

文章对某船发电机舱纵向混合构型加筋板的导纳特性进行了研究,运用模态叠加法求解了结构在线激励作用下各特征线上的等效导纳。计算结果显示,根据振动能量在结构上的分布,可按频段将导纳特性分为输入主控区和传递主控区。输入主控区导纳呈现带通特性,三个通频带与相应的筋条结构对应。通过改变筋条的参数可以单独控制加筋板某个频段的导纳特性。     

复合材料桅杆层合板刚强度分析研究

针对封闭式桅杆中复合材料层合板结构进行设计,提出复合材料层合板结构设计方案。综合利用有限元软件ANSYS和相关强度准则对桅杆的复合材料部分进行强度和刚度校核,分析并总结出相关特性。确定并得出满足要求的复合材料层合板厚组合,实现复合材料桅杆的优化设计。并验证了设计的可行性,为复合材料桅杆以后的设计研究提供参考。     

不同载荷形式下复合材料层合板渐进失效行为研究

近年来复合材料在船舶与海洋工程领域得到快速发展。船舶在服役周期内受载复杂,主要承载板材除受典型的面内拉压外载外,免不了遭受横向波浪载荷作用。研究复合材料层合板在不同载荷形式下结构的响应特征与损伤演化特性,有助于先进复合材料的性能评估及优化设计。本文采用三维实体单元及内聚力单元建立复合材料层合板模型进行计算分析,考察拉压载荷下层合板的极限承载能力与渐进失效过程,研究在横向载荷下层合板结构强度,对比分析其层内及层间损伤模式的差异性。     

Vibration transmission characteristics of composite laminate joints based on power flow北大核心CSCD

[目的]为了研究复合材料层合板连接节点的振动传递特性,提出一种采用有限元功率流法并结合功率流可视化技术的分析方法。[方法]首先,验证用有限元实体单元功率流描述板壳振动的有效性;然后,引入功率流传递率评价指标,提出有限元模型功率流传递率的计算方法,并以导纳功率流法计算结果为参照来验证其有效性;最后,建立嵌入式连接和螺钉连接这2种复合材料层合板的连接模型,计算其功率流传递率曲线和典型功率流矢量图。[结果]对比验证结果表明,2种连接模型的振动传递路径和功率流传递率存在明显差异。[结论]有限元功率流法直观反映了连接结构的振动传递能力及振动能量传递路径,可为复合材料结构设计提供参考。     

Analysis of impact damage characteristics of marine carbon fiber composite laminates embedded with PEI film北大核心CSCD

[目的]在传统船用碳纤维复合材料层合板层间添加热塑性相材料能有效提升船用复合材料的抗冲击性能,为探究其冲击损伤特性,开展实验研究。[方法]使用光学显微镜观察层合板的热塑性/热固性界面,分析两相材料的结合方式;对不同结构的复合材料层合板进行低、中、高3种不同能量的低速冲击;通过超声C扫描与电子显微镜,对各试件的损伤形貌进行观测,以研究各试件的冲击响应及损伤机理。[结果]结果显示,相较于碳纤维层合板,含热塑性相的船用复合材料层合板具有更好的损伤阻抗;内部嵌膜层合板试件在冲击能量为8和12 J的冲击下,内部分层损伤分别减少了19%和39%,且受到12 J冲击后,内部结构损伤较小,完整性较好。[结论]将PEI热塑性膜嵌于内部能提升层合板的韧性,显著减少内部分层损伤,明显提升内部嵌膜层合板的抗冲击性能。     

复合材料层合结构悬臂梁振动特性试验

以复合材料层合结构悬臂梁为研究对象，推导层合结构悬臂梁振动特性公式，计算层合梁的低阶固有频率。采用电测和光测两种试验方法，对复合材料层合结构悬臂梁的振动特性开展研究，并分析不同测试方法、传感器类型、测点数量、激励方式等对测试结果的影响。将理论与试验相结合，得到一种可应用于复合材料层合结构悬臂梁振动测试的试验方法。综合比较电测法与光测法中所有悬臂梁振动测试的试验方法，研究结果表明采用光纤式激光测振仪为优选。光纤式测振仪光学头与被测试件的垂直距离为0.5 m，采用锤击瞬态激励方式的采样时间为5 s，由该方法测量取得的悬臂梁振动试验数据误差最小。     

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.     

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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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。