三维仿真技术在航标管理中的应用研究

将三维仿真技术应用到航标管理中,有利于航标管理部门更加科学直观地对配布、监控、维护海上航标。通过深入研究IALA组织提出的有关"三维航标应用"推荐要求,分析近年来国内外高新信息技术在航标领域的应用情况,并结合航标日常管养的实际业务需求,开展了基于三维实时仿真技术的航标管养、监控等研究工作,并通过运用大型船舶操纵模拟器的高逼真三维视景仿真和船舶操纵仿真的功能,开展了具体的航标配布模拟检验应用研究工作。结合厦门港主航道航标配布的实际需求,从检验航标布设间距以及航道转向点航标布设最佳位置两个应用层面,介绍了如何利用大型船舶操纵模拟器为航标配布提供服务。     

基于支持向量机的船舶航向广义预测控制研究

船舶的动态性能具有大惯性、大时滞、非线性等特点,采用基于结构风险最小化原则的神经网络———支持向量机(SVM),充分发挥其可以任意逼近非线性模型的良好特性对船舶模型进行有效辨识,以此作为广义预测控制(GPC)算法中的预测模型,并加以相应的GPC算法达到保持航向的目的。仿真结果表明:SVM学习速度快,在小样本情况下具有良好的非线性建模和泛化能力;基于SVM的GPC算法在航向保持方面具有很好的控制性能。     

New method for ship finite element method preprocessing based on a 3D parametric technique

A new method for ship finite element method (FEM) preprocessing is presented as well as its program development. The method is applicable for all kinds of ships at different levels, such as a whole ship, cargo hold parts or detailed structures. The 3D parametric technique is used when creating ship structures, which improves the modeling efficiency greatly and makes the model easy to modify. A 3D geometric constraint solver is developed to solve the constraint system of the parametric model. A meshing procedure is presented to automatically convert the parametric structure model into a finite element model, by which high quality mesh is generated in the stress concentrated area. It also becomes possible to create finite element models for different levels from the same structure model. Using this method, the engineers avoid much of the complex and laborious work of FEM preprocessing, which consumes a very significant amount of time in finite element analysis, and can pay more attention to post-processing. This method has proved to be practical and highly efficient by several engineering trials. This work is sponsored by “Liaoning BaiQianWan Talents Program”.     

船舶纵向气囊下水宽支座弹性计算方法初探

本文介绍了船舶纵向气囊下水的气囊运动机理，构建了船体与气囊受力模型，并将船体、气囊与船台假定为串联弹簧体系，提出了船舶纵向气囊下水宽支座弹性计算方法。     

三体船兴波阻力计算方法比较及兴波干扰研究

分别利用Noblesse细长船理论和薄船理论,以Wigley三体船为例计算傅汝德数在0.20～0.70范围内多个侧体布局下的兴波阻力,探讨三体船两个侧体间和3个侧体之间的兴波干扰,得到对三体船设计具有指导意义的结果。通过与试验结果比较表明,基于首阶近似,不考虑线积分项的Noblesse细长船理论兴波阻力系数的计算结果与薄船理论非常相近。考虑线积分项的Noblesse细长船理论兴波阻力系数计算结果小于薄船理论的计算结果,后者量值更接近于试验值,但是两种计算方法的兴波阻力系数曲线凸凹点对应的傅汝德数相近,表明两种计算方法对兴波干扰现象的计算预测是相近的。研究表明,用薄船理论计算三体船的兴波阻力,探讨多体船侧体之间的兴波干扰目前是一种简便、可行的方法。     

宝兰客运专线麦积山隧道2号斜井突涌水特征与防治措施研究

铁路隧道大突涌水灾害一般认为发生于岩溶发育及断层构造带等易形成大型含水构造的地段,通过对宝兰客运专线麦积山隧道2号斜井的研究分析,普遍认为是工程地质及水文地质条件相对较好、富水性相对较弱的花岗岩隧道中的突涌水现象。并在勘察施工过程中运用地质调查法、物探法、超前水平钻法等多种勘察手段,结合区域背景资料综合分析,总结出花岗岩的构造节理定向等距、空间分布非均匀性、涌水量非线性变化、流态相对单一等特点及发育规律,并以此结论为基础论述突涌水防治措施方案的比选研究。最后施工验证了治理方案"顶水作业,辅助注浆封堵"的安全合理性。     

100-years-changes in the phytoplankton community of Kiel Bight (Baltic Sea)

Literature data from 1905/06, 1912/13 and 1949/50 were compared with recent data (2001–2003) from Kiel Bight in order to investigate changes in phytoplankton composition and biomass, which may serve as indicators of environmental changes. In terms of biomass, diatomophyceae and dinophyceae are by far the most important groups. Their ratio is still close to unity. The share of diatomophyceae increased strongly in years with exceptionally high summer blooms (2001) or exceptionally early spring blooms (2003). The summer and autumn blooms of Chaetoceros and Skeletonema, detected in the early 20th century, are replaced by other diatoms (Cerataulina pelagica, Dactyliosolen fragilissimus, Proboscia alata, Pseudo-nitzschia spp.). Chaetoceros and Skeletonema are still important components of the spring blooms. Now as before, the autumn blooms are dominated by Ceratium spp., sometimes also by diatoms. Newly appearing bloom-forming species are mostly potentially toxic (Dictyocha speculum, Prorocentrum minimum, Pseudo-nitzschia spp.). The total phytoplankton biomass has roughly doubled in the course of the last century. The reference condition for phytoplankton biomass in Kiel Bight in the sense of the Water Framework Directive was defined at 55 mg C m^− 3 (± 10%, annual mean). The mean annual biomass of diatomophyceae and dinophyceae was 25 mg C m^− 3 (± 40%) for each, indicating that the sum of their carbon biomass amounted to 90% (± 10%) of the total phytoplankton biomass on an annual average. Diatomophyceae represented at least 80% of carbon biomass in the spring bloom peak at the beginning of the 20th century.     

铁路机车、动车大部件清洗现状及解决措施

为了解决铁路机车、动车大部件清洗存在的问题,实现自动化清洗,保证清洗设备的稳定性和可靠性。在充分调研铁路大部件清洗现场及清洗设备的基础上,分析清洗大部件的影响因素和清洗效果不佳的原因,提出水射流喷淋清洗技术是大部件清洗最适合的清洗技术,并提出实现稳定和可靠清洗的解决措施,为大部件清洗设备的研制提供参考。     

6500DWT成品油船侧推器选型要点

通过对本船侧推器与船舵桨的匹配优化分析，寻求侧推器容量估算的基本方法，为相类似船的侧推器选型和计算积累经验或提供借鉴。     

集装箱船整船结构三维有限元强度分析方法研究

以3800TEU集装箱为例，用二维切片理论进行了波浪长期预报，并在此基础上导出等效波组，在整船结构有限元模型上计算船体结构在各等效波上的变形和应力分布。文中叙述的整船结构有限元分析方法，也可以用于其他类型船的整船结构分析。