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1.
用WPA法,亦称“波传递法”,对任意支承形式的梁在分布力激励下的动响应和动特性进行分析,并对均布力作用下的悬臂梁进行了理论推导,证明这种计算方法是正确的。  相似文献   

2.
防爆墙结构是海上浮式生产储油船(FPSO)上部重要防护设施,其在油气燃爆冲击下的动态响应需要重点关注。以FPSO上部模块为研究对象,基于计算流体力学(CFD)方法对油气燃爆场景进行数值模拟,获得了防爆墙表面压力时间曲线和空间分布;基于显式动态算法研究了波纹夹层防爆墙在燃爆载荷作用下的动态响应,并与等质量加筋板动态响应进行对比。研究结果表明:在防爆墙动态响应研究时,加载考虑负压和压力非均匀分布会使结果更准确,相比于加载平面内分布均匀的三角形载荷,考虑时间上负压阶段进行加载时,波纹夹层防爆墙永久变形减小;考虑超压空间非均匀分布进行加载时,波纹夹层防爆墙永久变形增大;考虑压力非均匀分布进行加载时,波纹夹层防爆墙永久变形要比加筋板小25.8%,抗爆性能更优。研究结论可为FPSO上部防爆墙设计及动态响应研究提供一定的参考。  相似文献   

3.
[目的]波传播分析法也称WPA法,在分析混合动力系统(如浮筏)中弹性波的抵消机制方面具有独特的优点。[方法]基于WPA法,从振动微分方程和弹性波的传播、反射视角解析结构噪声。[结果]分析表明:WPA法使研究者能够从表观参数(如振动加速度)进入内核参数(弹性波),深层剖析振动能量的注入、传导以及波与声辐射之间的因果关系。WPA法可嵌入谐力相位表达,能够研究多源抵消机制;由于采用指数型函数,方程的推导具有规律性和规整性,适合工程技术人员开展深入的机理分析。[结论]从"复杂系统"到"简单系统"抽象,WPA法更容易发现共同性和关键性的一般科学规律,从而实现系统动力学性能的极致设计。  相似文献   

4.
以“澎湖号”半潜式波浪能养殖平台为研究对象,采用基于1阶泰勒展开边界元法的中国数值水池软件,建立增加等效波浪载荷面积模拟生物附着的简化仿真方法,对6种生物附着覆盖面积率下的养殖平台频域运动响应进行分析。作为对均匀分布假设的修正,同时给出2种生物附着不均匀分布的模型,并将其计算结果与均匀分布模型的计算结果相对比。结果显示,网衣生物附着对平台横荡和垂荡2个自由度运动特性的影响显著,运动幅值最多增大10%左右,横荡2阶力增幅可达115.97%。  相似文献   

5.
为研究剪切流作用下立管的涡激振动问题,文章建立了三维立管的涡激动力响应方程,顺流方向的力通过Morison方程求解;横向涡激力采用改进的尾流阵子模型求解,考虑了附加质量的变化;轴向力的计算考虑平台升沉运动的影响。采用有限单元法离散控制方程,离散后的方程采用Newmark-β法在时域求解。在此基础上,研究了剪切流作用下立管的多模态涡激振动响应,讨论了剪切参数对立管涡激动力响应的影响,并比较了均匀流和剪切流条件下立管不同的响应特征。结果表明,剪切参数对立管的涡激响应动力响应有很大的影响,剪切流条件下立管呈现的多模态响应极为复杂,与均匀来流条件下的振幅和频率响应特点明显不同。  相似文献   

6.
蒋勇  李成现 《中国水运》2004,2(4):79-80
本文采用三维有限元分析方法,对不同车辆及其轮载作用力的均匀和非均匀分布情形下沥青路面的力学响应进行了分析.通过分析发现,考虑更接近实际轮载对沥青路面的作用,对更深入的了解沥青路面结构的力学行为至关重要.  相似文献   

7.
不同阻尼情况下减振浮筏振动响应计算研究   总被引:1,自引:0,他引:1  
提出一种计算减振浮筏系统振动响应的方法,建立浮筏系统力学模型,研究阻尼对系统响应的影响,并以一实际浮筏系统为例,分别使用振型叠加法与数值积分法计算了位移,速度响应及传递至基础的力、所得结果完全一致。  相似文献   

8.
在考虑运转状态下轴系自身陀螺效应和所受脉动载荷的条件下,建立的微分方程组在空间和时间上是耦合的,难以采用常规方法在数值上进行精确求解。拟小波法拥有全局方法的高精度和局域方法的灵活性,适合于非线性耦合微分方程的求解,可用来求解旋转船舶轴系的动力学方程。采用拟小波求解无轴向力作用时旋转轴的动力响应,将它与解析解对比,验证了该方法的可行性和有效性。在此基础上,用该方法求解船舶轴系受到螺旋桨产生的周期性轴向力作用时的动力响应,讨论了转速和周期性轴向力的影响。计算结果表明在特定转速下轴系的位移响应会发散,呈现了周期性轴向力的影响。  相似文献   

9.
冲击载荷下加筋板非线性瞬态分析   总被引:1,自引:0,他引:1  
本文用半解析的方法分析了横向冲击载荷下加筋板的非线性瞬态响应。考虑膜力的存在,忽略筋截面上的剪切应力,引入板的应力函数,采用离散加筋板模型,运用能量原理建立加筋板的动响应控制方程。假设挠度为双级数形式,运用迦辽金法,将加筋板的动响应方程转化为一个多自由度的动力系统,采用数值方法来求解。本文最后给出了几个模型的计算结果。  相似文献   

10.
在结构声传播和声场响应研究中,往往需要以设备的激励特性作为计算模型的输入。若虚拟力作用下的结构响应与真实响应一致,可用虚拟力代替真实激励作为模型输入。文章在前人虚拟力模型的基础上结合改进的分部优化正则化方法,解决测量导纳矩阵的病态问题,提高虚拟力估算精度。文中通过电机模型实验对比了不同正则化方法下虚拟力对结构响应的重构误差,验证文中方法在虚拟力估算中的可行性和准确性。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
14.
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;  相似文献   

15.
联合作战计划和执行系统   总被引:2,自引:1,他引:1  
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。  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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).  相似文献   

20.
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.  相似文献   

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