Design of offshore structures against accidental ship collisions

In this paper, we investigate the damage to offshore platforms subjected to ship collisions. The considered scenarios are bow and stern impacts against the column of a floating platform and against the jacket legs and braces. The effect of the ship–platform interaction on the distribution of damage is studied by modeling both structures using nonlinear shell finite elements. A supply vessel of 7500-ton displacement with bulbous bow is modeled. A comprehensive numerical analysis program is conducted, and the primary findings are described herein. The collision forces from the vessel are compared with the suggested force–deformation curves in the NORSOK code. For collisions with floating platforms we particularly focus on the crushing behavior and potential penetration of the bulbous bow and stern sections into the cargo tanks or void spaces of semi-submersible platforms. For fixed jacket platforms we investigate whether jacket braces can penetrate into the ship without being subjected to significant plastic bending or local denting.Adequate treatment of the relative strength between the interacting bodies is especially relevant for impacts with high levels of available kinetic energy, for which shared energy or strength design is aimed at. Simplifying one body as rigid quickly leads to overly conservative and/or costly solutions, and is in some cases non-conservative.The numerical analysis is used to develop a novel pressure–area relation for the deformation of the bulbous bow and stern corners of the supply vessel. Procedures for strength design of the stiffened panels are discussed. Refined methods and criteria are proposed for strength design of platforms, including both floating and jacket structures. The adequacy of the NORSOK design guidance for collisions against jacket legs is evaluated. The characteristic strength of a cylindrical column is used to develop a novel criterion for the resistance to local denting from stern corners and bulbous bows.     

民用船舶直流电网发展现状分析

随着世界传统化石能源的日益枯竭,石油价格节节攀升以及电力系统电子技术的发展,船舶行业越来越关注直流电力系统在船舶上的应用。目前已有企业凭借自己的技术优势率先开发了新型直流电网的船舶,并投入了应用。本文对船舶电力系统采用新技术的优缺点及应用情况进行分析,提出当前需要解决几个问题。     

PBA工法地铁车站下穿桥梁方案优化研究

文章以北京地铁6号线花园桥站下穿花园桥为工程背景,采用FLAC3D数值模拟和层次分析法确定PBA工法(Pile-Beam-Arch Method)地铁车站下穿桥梁的最优方案,并结合监测结果分析了关键施工阶段对地层和桩基的影响。研究表明,同等注浆加固条件下4导洞法控制远、近侧桩基位移效果比5,6导洞法稍好,相同车站施工方法和结构型式下对近侧桥桩区域适当注浆加固和大范围注浆加固效果相近,因此,确定5导洞法及近侧桥桩区域内适当注浆加固为最优方案;导洞开挖、扣拱和其它工序地表沉降比例为0.38∶0.32∶0.30;导洞开挖和扣拱对近侧桩基位移影响较大,站台层开挖对远侧桩基沉降影响最大,导洞开挖和扣拱影响次之,但对水平位移影响较大。     

内河多功能救助船舶动力装置设计分析

介绍了多功能救助船舶的设计和选型,分析了该船在不同工况下动力装置的功率匹配问题,给出了该船舶动力装置的最佳匹配的设计,以便在救助过程能充分发挥其救助功能。对该类多功能救助船舶的设计具有较好的参考价值。     

FYJK-1型微机风源监测与控制系统的几点改进

本文分析了FYJK-1型微机风源监测与控制系统存在的问题，并提出了解决方法。     

供应链合作伙伴选择问题研究

本文提出了选择供应链合作伙伴的一般原则,即核心能力原则、总成本原则、敏捷性原则和风险最小化原则,并利用"三阶段法"即初选阶段、单目标评价阶段、综合评价优化阶段,根据择近优化原则进行定量计算,为供应链合作伙伴的选择提供一种定量的方法。     

关于我国航海人才培养的经济学思考

随着经济全球化进程的加快,国际贸易持续增长,航海人才业已成为航运业发展的重要支撑。中国是一个人力资源大国,开发航海人才资源前景广阔。本文首先分析了我国航海人才供需现状,阐述了航运业存在的突出问题是人才的供需失衡,进而从经济学角度对航海人才的供给进行分析,并提出了解决问题的相关建议。     

IEC104规约在城轨电力监控系统中的应用

介绍了IEC60870-5-104规约,分析了该规约在城市轨道交通电力监控系统应用中的优势,并结合广州地铁三号线基于IEC60870-5-104规约的变电所通信软件的设计需求,给出了IEC60870-5-104规约在城市轨道交通电力监控系统中应用的典型设计方法。     

270 km·h-1动力车驱动制动单元悬挂参数的优化

为进一步改善270km·h-1的轮对空心轴式动力车的性能,采用多刚体动力学软件SIMPACK建立了完整的动力车动力学模型,在高、低干扰线路上分析了驱动制动单元车体端、构架端悬挂刚度和耦合减振器阻尼特性对单元各向振动加速度和动力车平稳性能的影响。结果表明优化单元悬挂参数可以改善其工作条件和整车性能,但对轮轨作用力影响不大。相同速度不同级别线路上,单元悬挂参数对动力车性能的影响规律是相似的。     

混合动力电动汽车结构分析

混合动力电动汽车（HEV）是指以蓄电池与辅助动力单元（APU）共同作为动力源的汽车。由于混合动力电动汽车在节能和降低排放污染方面的明显优势，因而受到很大的重视，研制开发和产业化的进程相当快，目前混合动力电动汽车主要有两种混合驱动结构，串联式和并联式，对这两种混合动力系统结构和特点进行了分析，并重点对并联式结构中的不同结构进行了分析介绍。