应用广义拟余能原理研究流固耦合问题(英文)

水动力学与固体力学交叉的流固耦合理论是船舶与海洋工程结构响应分析与直接设计的重要工具.本文应用卷变积方法,按照广义力和广义位移之间的对应关系,将弹性动力学的基本方程卷乘上相应的虚量,然后积分,代数相加,并考虑到体积力和面积力均为伴生力,建立了非保守系统初值问题的两类变量的广义拟余能原理.应用广义拟余能原理研究流固耦合问题,分析了结构的动力响应,给出同时求解力类量和位移类量两类变量的计算方法.     

天津海事局：应对金融危机 十项措施服务港航企业

2008年12月11日,天津海事局宣布即日起将通过“提高港口船舶通航效率、公布天津主航道新的通航标准”、“推荐天津港砂石运输船舶专用航路”等十项措施,支持港航企业抵御金融危机。 天津海事局副局长黄何介绍,为支持港航企业抵御金融危机,尽可能地减轻金融危机带来的不利影响,天津海事局提出了十项措施,尽最大的努力协助天津地区港航企业渡过难关。     

海底输气管道泄漏风险定量分析

由于海底管道工作环境的恶劣性,其失效概率较高,一旦发生泄漏事故,后果严重．本文以某一海洋平台周围海底输气管道为背景,运用海洋工程领域风险评估软件NEPTUNE对不同破损情况下天然气泄漏扩散的情况进行了模拟,计算了泄漏气体点燃概率,预测了泄漏天然气爆炸事故的危害半径,其分析结果对海底管道油气泄漏扩散范围的预测及油气点燃概率计算方法的研究具有一定的参考作用．     

中国港口信息化30年辉煌建设及其展望

回顾了中国港口信息化建设30年的主要历程,阐述了中国港口信息化领先水平的表现和用高新技术改造传统产业的成绩。介绍了中国港口信息化的典型成果——电子政务和港航企业信息化对港口生产管理的促进作用,证实了我国港口建设坚持用“高新技术改造传统产业,提高管理水平”这一发展原则的正确性。     

Analysis of velocity fluctuations and their intermittency properties in the surf zone using empirical mode decomposition

We consider here surf zone turbulence measurements, recorded in the Eastern English Channel using a sonic anemometer. In order to characterize the intermittent properties of their fluctuations at many time scales, we analyze the experimental time series using the Empirical Mode Decomposition (EMD) method. The series is decomposed into a sum of modes, each one narrow-banded, and we show that some modes are associated with the energy containing wave breaking scales, and other modes are associated with small-scale intermittent fluctuations. We use the EMD approach in association with a newly developed method based on Hilbert spectral analysis, representing the probability density function in an amplitude–frequency space. We then characterize the fluctuations in a stochastic framework using a cumulant generating function for all scales, and compare the results obtained from direct and classical structure function analysis, to EMD–Hilbert spectral analysis results, showing that the former method saturates at large scales, whereas the latter method is more precise in its scale approach. These results show the strength of the new EMD–Hilbert spectral analysis method for data presenting a strong forcing such as found in shallow water, wave dominated situations.     

船舶污水处理技术现状与MBR应用前景展望

介绍了船舶污水的种类及产生危害,对生活污水处理技术、油水分离技术以及灰水处理技术的现状做了分析,并介绍新型污水处理技术-MBR,论述了该技术应用在船舶上的优点以及研究前景。     

绞吸式挖泥船门架结构强度分析

本船为1艘4000m^3／h绞吸式挖泥船,起吊系统包括龙门架结构和桥架结构。选取两种代表性工况,运用MSC／Patran／Nastran有限元分析软件对起吊系统建模并进行结构强度分析。对龙门架和桥架销座附近结构的应力和位移做了校核,为同类型挖泥船起吊系统的结构安全和结构经济性提供了参考。     

简析地铁安全门驱动控制器的控制构架

针对地铁安全门驱动控制器,提出了一种电机控制软件构架。该构架以嵌入式操作系统为基础调度各控制任务,将控制任务分为高优先级任务和低优先级任务。在该控制构架基础上,完成了地铁安全门驱动控制器的软件系统,并在样机上进行了应用测试。试验表明,该电机控制软件构架运行稳定,能有序地调度各控制任务,并具有良好的复用性和扩展性。以该构架为基础开发的驱动控制系统控制精度高,动态响应好,能够满足现场应用的需求。     

智能船舶集成设计技术

针对符合CCS《智能船舶规范》入级符号的船舶设计开发,研究分析智能船舶集成设计技术的设计思想、设计要素、设计框架和关键技术,设计目标船解决方案,并讨论了未来需要突破技术方向。     

Property Evolution of Sulphoaluminate Grouting Material under Pressure Circulation北大核心CSCD

Water-sealed underground oil tank projects are quite different from traditional underground projects since the water-sealing conditions are very strict and the difficulties caused by the geological specificity, structural specificity and construction specificity are key factors affecting the project. In light of the significant early initial setting time and rapid temperature increase of sulphoaluminate cement-based grouting material for a large domestic water-sealed underground oil tank with pressurized cyclic grouting, a laboratory grouting simulation is conducted. It is found that the properties of the sulphoaluminate cement-based grouting material are quite different under different pressure cycles, the hydration exothermic peak time gets shorter with an increase of circulation time, the compressive strength decreases with an increase of circulation time, and the longer the circulation time the more obvious the de-crease of compressive strength. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.