管子弯曲回弹切线数学模型研究

为了实现管子弯曲加工精确无余量计算,需要解决管子弯曲后在两个方向上不对称的切线值的精确计算难题.本文通过管子弯曲实验研究,分析计算得出管子弯曲回弹切线数学模型,然后将管子弯曲回弹切线数学模型应用到实际弯管加工中进行验证.为管子无余量弯曲加工、先焊后弯加工奠定了基础,对推进高效的管子弯曲加工应用有一定的指导作用.     

管形数据转换及管件信息模型表达

针对常用三维CAD软件在处理和表达管形数据方面存在的不足,本文介绍了管形数据两种描述方法,并给出了管形设计数据至加工数据的转换模型。基于导管STL模型的几何信息自动提取算法能够实现常用CAD软件设计的导管模型信息的自动提取,从导管加工CAD/CAM集成的角度建立了基于特征的导管零件信息模型,该模型能够充分表达用户对导管的加工缺陷控制要求,为实现导管加工的CAD/CAM集成提供了统一的产品数据模型。     

曲面分段全建造流程的误差累积及精度预测

以海洋平台典型曲面分段为研究对象,梳理建造企业对切割和弯曲工艺的精度要求及误差响应,以及焊接工艺对应的典型接头力学载荷,并将其作为曲面分段建造的源头误差。基于弹性有限元方法,分析焊接工艺对曲面分段建造精度的影响;考虑切割和弯曲误差对焊接工艺的影响,并预测闭合加工误差的焊接工艺及其产生的焊接变形。为提升曲面分段建造精度的评估效率,建立基于遗传算法的BP(Back Propagation)人工神经网络,并以27组数据为训练样本,以9组数据为验证样本检验其预测的准确性。通过弹性有限元分析研究不考虑、保留及矫正切割和弯曲加工误差等3种情况下的曲面分段建造精度,结果发现三者存在明显差异。考虑切割、弯曲的加工误差及其焊接闭合工艺对曲面分段的建造精度的显著影响,基于遗传算法的BP人工神经网络具有极高的预测精度和稳定性。     

一种新型智能微控肋骨冷弯机问世

由福建省渔轮修造厂与中国船舶工业总公司船舶工艺研究所等几家单位联合研制的国内第一台WLW-50T智能型微控肋骨冷弯机问世。这种冷弯机具有稳定可靠、操作简便的特点,实现了进料、弯曲、回弹及伸长检测、垂向校平、打印号料等肋骨加工全过程的计算机自动控制,提高了船舶肋骨的加工精度和生产效率,改善了劳动条件。     

感应加热板材成形的有限元分析及工艺规划

通过感应加热实现板材的热弯成形,具有精准控制、安全便捷等特点。本研究采用新型便携式感应加热设备,对8mm船板钢进行热弯成形试验;并基于热-弹-塑性及弹性有限元计算,预测感应加热面外弯曲变形,与测量数据基本吻合。同时,考虑试验成本高昂,通过大通量的有限性计算,建立感应加热参数与板材弯曲的数据库;并通过回归分析,拟合出感应线圈移动速度与板材弯曲角度间的数学关系。当板材弯曲曲率相同时,通过线加热位置的迭代二分法,可线性逼近板材的目标弯曲形状,进而快速规划加工工艺,并进行了验证。     

船舶螺旋浆长导管的水头损失及优化计算

对一变截面弯曲船舶螺旋浆长导管的水头损失进行了计算,根据长导管具全布置情况,将水头损失分为进口段,弯曲段,收缩段,轴承,支架段,弯曲段,扩张段以及出口段第十个部分分别计算,并进而计算了为克服这些损失和流动阻力所需的螺旋浆推力。对应某一确定的螺旋桨直径,依据流动损失和浆推力计算,对长导管进出口的直径进行了优化计算。     

船体外板火焰成型加工专家系统

本文介绍了该系统的基本功能及其软件设计方法,给出了系统的软件结构及运行方式。并着重阐述了外板自重弯曲的算法分析以及基于知识的加工方法选择专家系统的结构和建立方法。     

避免肋骨弯曲伸缩变形影响成形精度的新方法

分析肋骨弯曲加工中产生长度伸缩变形对成形过程及结果的不利影响,提出以型材中性轴曲线为成形依据的新控制原理及测量方法,以实现完全避开伸缩变形影响的高精度弯曲成形。     

大中型不锈钢薄壁管弯曲防皱装置的研制

针对大、中型不锈钢薄壁管采用中中热弯曲法或弯头对接法加工的诸多不足,研制了弯曲防皱装置进行冷弯曲加工,此法具有降低成本、缩短加工工时,且不改变管子性能等优点。     

国外舰船先进制造技术——其他先进制造技术

1水火弯板计算机应用系统 1．1水火弯板计算机应用技术背景 目前在船体建造过程中,钢板弯曲加工之前的船体设计、放样、展开、号料、切割等均实现了计算机化,其后的装配、焊接均初步实现了机械化和流水线化,只有钢板加工这一环节仍相对落后,钢板加工的成形率还不能满足要求,这已成为制约造船生产率提高的一个瓶颈。     

Development of a computer-aided process planning system based on a knowledge base

 Process planning for a hull structure defines the assembly sequence of the hull block. Although this activity is very important because the working strategy defines the production costs, to date it has been done manually. To raise the efficiency of this process, we developed a practical computer-aided process planning system. It has been developed using deliverables obtained from advanced computer integrated manufacturing system (CIM; ACIM) for shipbuilding projects sponsored by the Ship and Ocean Foundation (SOF). The system has a knowledge base which contains the know-how of skilled designers as well as design practices, and allows the assembly sequence of hull parts and intermediate products to be defined automatically. The system has been integrated with the shipyard CAD system MATES, and put to practical use. Received: August 19, 2002 / Accepted: November 25, 2002 Address correspondence to: Y. Sasaki (yuuichi_sasaki@mhi.co.jp) Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:309–315)     

基于某系列船建造阶段轴系安装工艺探究

结合某系列船船舶建造船舶检验,对船舶轴系安装前环境条件及实际轴系安装过程中的照光过程、艉管镗孔、轴承压装等工艺进行梳理分析。通过轴系安装检验过程中发现的尾轴内部缺陷和轴承安装超压案例,结合轴系安装工艺梳理分析结果,提出铸钢件丝状缺陷和压装失败后铸钢件产生严重缺陷相关规范要求及解决方案,通过查找根源问题对轴系安装工艺提出改进建议。为未来大型化,精细化船舶建造中轴系工艺顺利进行打下坚实基础。     

管子智能生产线工艺布置设计

为了满足多元化船舶产品生产需要,设计一种具有高柔性、高效率的综合管子智能生产线的工艺布置.它在硬件上符合DN 40～DN 400管径碳钢管加工工艺流程要求,在软件上与公司现有的ERP系统对接,并自带MES系统,实现全自动区及半自动区的信息及物流顺畅贯通.所设计的工艺布置兼顾智能、高效、柔性生产特点,工艺适应范围广,产能...     

船舶上层建筑完整性设计建造工艺

基于上层建筑完整性设计建造的成功经验,对船舶上层建筑完整性设计建造工艺进行研究。各船厂可根据自身的硬件条件和设备设施进行上层建筑的策划、设计和建造,并在完整性水平评估基础上进行持续改进,不断提高上层建筑中间产品完整性交付水平,从而提升船舶建造的生产效率。该研究为各船厂进行流程再造、实现上层建筑完整性设计建造提供技术指导。     

航路规划对远程鱼雷远程打击目标的影响

利用远程武器对目标进行超视距远程打击是未来海战的主要手段之一,航路规划技术对提高远程水下武器的安全性及突防攻击能力起着重要作用,根据远程打击目标的特点及影响航路规划问题的因素,提出了远程鱼雷航路规划的基本流程,最后分析了在远程打击过程中,航路规划对远程鱼雷提高远程打击效果的影响。     

纳米流体水平管内沸腾流型的模拟研究

利用UDF编程定义纳米流体相变源项,对Al2O3-H2O纳米流体在水平管内的沸腾过程进行了数值模拟,分析研究了纳米流体在水平管内沸腾的流型特点,结果表明水平管内沸腾蒸发产生的相变含气率沿着管长方向不断增加,但相同截面位置纳米流体的含气量高于纯水的含气量,有助于强化流体的扰动与混合。对于不同浓度的Al2O3-H2O纳米流体的流型研究表明：颗粒浓度对于纳米流体管内沸腾过程的影响不大。随后将纳米流体与纯水的流型进行比较,结果表明Al2O3-H2O纳米流体使得管内沸腾更剧烈,也更容易沸腾,这将改善水平圆管的流动特性。     

改进的脉冲声管法(英文)

Based on existing low-frequency water-filled impedance tube testing facilities, which is a part of the Low Frequency Facility of the Naval Undersea Warfare Center in Beijing, an improved water-filled pulse tube method is presented in this short paper. This proposed study is significantly different from the conventional pulse tube method because of the capability for a single plane damped sine pulse wave to generate in the water-filled pulse tube with a regular waveform and short duration time of about 1ms. During the generation process of the pulse, an inverse filter principle was adopted to compensate the transducer response. The effect of the characteristics of tube termination can be eliminated through the generation process of the pulse. Reflection coefficient from a water/air interface was measured to verify the proposed method. When compared with the expected theoretical values, a relatively good agreement can be obtained in the low frequency range of 500-2 000 Hz.     

Policy making and planning for the port sector: paradigms in conflict

Policy making is a complex and diverse process—particularly in relation to the provision and location of port and port related infrastructure. The planning stage of port infrastructure, or indeed transport planning more generally, may be finalized only to experience policy failure as implementation of the planned facility cannot be successfully completed. When this occurs planning and implementation failure is invariably perceived to be driven by a political agenda and it is argued that 'politics gets in the way'—that politics 'distorts' a scientifically rational planning process. Is it the case that politics 'gets in the way'? Or that politics distorts a technical and scientific process? Or is it the case that planning constitutes only one part, but an integral one, of the policy process—a process that is inherently political? And if that is the case, can we legitimately separate the planning process from that of policy making? This paper discusses the fundamental differences between the planning and policy-making processes. It argues that transport planning is one element in a broader process of policy making which incorporates political and other social/economic/environmental elements. It will argue that planning is a fundamental part of the policy-making process and, if successful completion is to be achieved, it cannot be divorced from that process. The paper will provide a conceptual framework which will incorporate these apparently conflictual activities. This model, if adopted, is likely to enhance both the planning and policy-making processes.     

沉管作业系统装船技术要点分析

针对沉管运输安装一体船的沉管作业系统进行分解研究,分析动力系统集成、作业绞车系统、压载调驳系统、气象观测系统、拉合系统、动力定位（Dynamic Positioning,DP）系统、施工管理系统和船管对接等设计和建造方面的技术要点,阐明沉管作业系统的装船精度控制关键点,提出可行的工艺控制方法,为沉管运输安装一体船的研制提供技术保障。     

钢管混凝土在海洋码头引桥工程中的应用

通过海洋码头引桥工程实例,介绍了大流动度、自密实、高强度、微膨胀及缓凝混凝土在大跨、多跨钢管混凝土拱桥中的配合比设计及要求,并对钢管混凝土泵送施工方法、工艺流程、施工过程控制等进行了阐述。使用效果证明,采用本钢管混凝土及其施工方法,能有效避免钢管混凝土拱桥施工中常见的混凝土离析、堵泵、钢管爆管、混凝土不均匀或不完全密实等问题,综合效益显著。