船台起吊能力的优化

本文在收集大量资料的基础上，综合分析了船台起吊能力与船体分段划分、分段重量与尺度、预舾装率、船台周期等相关因素的关系，并针对某船厂的实际生产状况和发展目标，运用模糊数学的方法对船台起吊能力进行了模糊综合评判。同时对臂架式起重机和门式起重机的工作特性进行了分析对比，对某船厂船台上起重机类型的选配方案做了优化，并对投资方案进行了技术经济分析，为新建船厂和老厂技术改造中确定船台的起吊能力提供了一种优化决策方法。     

Aspects of the stability of jack-up spud-can foundations

A three-level procedure for assessing jack-up foundation stability for more or less homogenous soils is described. The objective is to provide a rational framework for these assessments that ensures their safe operation in extended year-round operations and enables their use in deeper waters than at present.

The three levels of the procedure have to be entered successively as long as foundation stability cannot be proven. The first level is a screening exercise and essentially replaces the well-known preload check. The second level compares factored foundation loads resulting from a structural analysis with foundation capacities obtained with ultimate bearing capacity formulae. The most refined third level assesses whether the displacements associated with these loads lead to an acceptable situation, i.e. capacity increase and/or load redistribution that does not result in collapse of the jack-up unit.

Since, for maximum benefit, this third-stage analysis requires a non-linear foundation model to be linked with the structural package used: such a tool is provided in the paper. Examples are given to demonstrate the impact of the assessment procedure.

This procedure forms part of the overall in-house approach to the assessment of jack-ups and has already been offered to the jack-up industry as part of the continuing efforts towards establishing common and accepted standards for jack-up assessments. Further developments have been identified and will be pursued.     

模糊综合评价法在船舶溢油事故定级中的应用

对船舶溢油事故定级很有必要.通过模糊数学的方法,建立船舶溢油事故定级的评判模型,为事故定级评判提供了依据.通过实例,给出了具体的评价过程,证明该方法对于船舶溢油事故定级有借鉴作用,但此方法尚处于研究阶段.     

基于模糊信息融合的船舶动力装置综合故障诊断方法研究

在模糊集理论的基础上,将决策级信息融合技术应用于故障诊断系统中,提出了一种基于系统模糊综合评价融合结构下的综合故障诊断方法.该方法以模糊逻辑运算和全局决策融合来自多传感器的局部判决来获取诊断对象的综合诊断结果,并对船舶主动力系统的运行故障进行诊断研究,结果表明,该方法准确有效,为船舶动力装置故障的智能化诊断提供了有益的借鉴.     

常规潜艇总体设计评价准则和评估方法研究

基于常规潜艇的综合作战能力、可靠性、维修性、保障性、风险性和全寿命周期费用(即经济性)等主要属性,建立了常规潜艇总体设计的综合评价准则,给出了评价准则的计算公式和常规潜艇总体设计的评估方法.举例说明了综合评价准则和评估方法在常规潜艇总体设计过程中的参数分析、系统综合和方案评估时的重要作用.     

城市供水管道抗震可靠度评估方法与应用

该文针对城市供水管道地震破坏机理,介绍常用的经验评估方法,以及理论分析评估方法的思路。采用我国现行管道抗震设计规范的理论计算模型,以结构可靠度分析的一次二阶矩方法的思想,考虑了管道抗力、场地条件、管土相互作用的随机特性,给出了城市供水管道抗震可靠度评估的验算点法的计算过程。对计算过程中参数进行了敏感性分析,确定参数的重要性。最后与日本水道协会(JWWA)经验方法进行对比,证明方法的可行性,并对规范理论计算方法提出一些建议。     

基于图像分析技术的混凝土表面色差检测及评定

混凝土色差是混凝土结构外观质量检测与评定时的重要参数之一。目前,混凝土色差的评定主要依据检测人员的经验对混凝土表面颜色的均一性进行直观定性判断,其结果难以客观评定混凝土的外观质量。基于图像分析技术的应用,提出采用数码相机现场采集混凝土结构表面图像,对图像进行灰度转换,计算灰度图像的标准差,考虑人类视觉识别特征和拍摄环境的影响,建立混凝土表面色差的定量评价体系和方法。基于所提方法,对一混凝土结构的表面进行了对比试验,结果表明：该方法能有效检测与评定混凝土表面色差缺陷。     

BP和RBF神经网络在边坡稳定性评估中的比较研究

通过实例分析,对BP神经网络和RBF神经网络在边坡稳定性评估中的应用进行了比较研究,结果表明,BP神经网络和RBF神经网络均能很好地对边坡稳定性进行评估,但RBF神经网络比BP神经网络的训练速度更快,效率更高,并且对于同样的精度要求,RBF神经网络对边坡稳定性的评估结果更加准确和适用。     

工程机械融资租赁的风险控制

为了更好地控制工程机械融资租赁的风险,针对工程机械融资租赁这一特殊行业的特点,通过工作总结和文献研究,对融资租赁中的风险加以分析、评价,提出了相应的风险控制方法,对工程机械融资租赁的风险控制具有指导意义.     

考虑不确定性因素的路径优化(英文)

A route optimization methodology in the frame of an onboard decision support/guidance system for the ship’s master has been developed and is presented in this paper.The method aims at the minimization of the fuel voyage cost and the risks related to the ship’s seakeeping performance expected to be within acceptable limits of voyage duration.Parts of this methodology were implemented by interfacing alternative probability assessment methods,such as Monte Carlo,first order reliability method(FORM) and second order reliability method(SORM),and a 3-D seakeeping code,including a software tool for the calculation of the added resistance in waves of NTUA-SDL.The entire system was integrated within the probabilistic analysis software PROBAN.Two of the main modules for the calculation of added resistance and the probabilistic assessment for the considered seakeeping hazards with respect to exceedance levels of predefined threshold values are herein elaborated and validation studies proved their efficiency in view of their implementation into an on-board optimization system.