舰用电子设备结构可靠性模糊综合评估研究

雷达等军用电子设备的可靠性,主要取决于电信功能的稳定性和结构的可靠性,历年来,电信功能一直作为军用电子设备重点受到极大重视,且早已建立了可靠性的评估体系和验证手段,并日趋完美,从而推动了电信设计水平的发展和提高,而对军用电子设备的结构设计水平及其可靠性的评估,却一直未能形成相应的体系,本文根据军用电子设备结构系统失效模式的多样性,相关性,不同程度性及其失效过程的模糊性等特点提出了结构可靠性的模糊综合评估方法,给出具体的综合评估数字模型和公式,并以某舰用电子设备结构系统为例说明了该方法的应用过程。     

电子设备振动分析与抗振设计

军用电子设备工作环境恶劣,在结构上对整机进行加固的同时,还应采用隔振缓冲系统来提高其抗振、抗冲击等能力,从而提高军用电子设备的可靠性和使用寿命.通过分析电子设备的振动,详细介绍了军用电子设备结构加固的常用方法和隔振设计.     

某型机载电子设备无失效数据可靠性研究

针对寿命试验过程中未出现失效样本,传统的可靠性分析方法不适用于分析该类产品可靠性的情况,以某型机载电子设备的无失效数据可靠性分析为例,采用贝叶斯无失效数据可靠性评估方法,并综合考虑失效率上限分析其可靠性水平。该方法的预测结果与试验数据相符,在一定置信水平下具有较高的预测精度。     

海上军用信息安全系统的实现与评估

海上军用信息是未来海战的核心内容。本文首先从信息发送、信息接收和信息显示3个方面实现海上军用安全系统,然后利用模糊综合评价准则进行系统的安全评估。在评估实现的过程中,采用二级指标的模糊综合评估,并且通过实例说明本文所采用的评估方法在实现海上军用信息安全系统评估中简单有效。     

基于可靠性的某型平台罗经维修与保障方法

针对某型平台罗经维修要求,结合平台罗经电子机柜特点和当前维修方式与备件储备方式,通过失效样品分析,确定失效机理属性;通过可靠性预计和现场使用数据跟踪分析,建立可靠性水平综合评估模型,从而为平台罗经以可靠性为中心的维修与保障提出探索性解决方案,文章详细讲述了某型平台罗经以可靠性为中心的维修与保障方法的内容、思路、过程,并给出了结论。     

基于全周期抽样的搜索自适应Monte Carlo重要抽样法的船舶总纵强度可靠性研究

引入随机过程理论,确定表征船舶总纵弯曲载荷和强度的随机变量的概率分布及统计特征,针对船体梁总纵弯曲的失效模式,提出全周期抽样的搜索自适应Monte Carlo重要抽样法进行船体总纵强度可靠性分析;该方法对传统的Monte Carlo法进行改进,有效地平衡了Monte Carlo方法的计算速度与计算精度之间的矛盾,利用较少的抽样次数可得到更加理想的抽样密度函数和收敛速度更快、精度更高的失效概率计算结果;最后以某军用艇为例,分别采用本文方法与JC法进行船体总纵强度可靠性评估,并对计算结果进行了比对分析.     

船体梁与加筋板极限强度可靠性设计

本文应用结构可靠性分析方法,分别以船体梁和船体纵向加筋板极限承载能力为失效模式,对船体结构进行了安全评估和可靠性设计。应用所开发的新的改进可靠性计算方法,计算了基本物理量的不确定性对船体结构极限强度函数统计特征的影响,同时结合所开发的用于直接估算船体梁和加筋板极限强度的荛用计算方法,确定出不同船体结构的失效概率和设计目标安全指数,推导了局部安全因子,可以进行船体结构的可靠性设计与再评估。     

印制板模块生产的质量控制方法*

印制板模块是军用电子设备的基础性部件之一,其质量对电子设备的可靠性影响较大。论文从设计和生产两个角度系统地分析影响印制板模块产品质量的重要因素,并结合实际情况,对小批量、多品种生产模式下产品的质量控制提出了切实可行的方法。     

基于共因失效的海水系统多状态可靠性分析

针对海水系统在运行过程中,由于工作环境差异导致海水泵独立失效率不同,同舱室海水泵存在共因失效的问题,考虑到基于相同单元独立失效的可靠性分析方法不能准确分析海水系统的多状态可靠性,文章提出一种在包含共因失效的相同单元存在不同独立失效率的情况下,结合通用生成函数和马尔科夫过程的多状态可靠性分析的新方法,建立基于通用生成函数的多状态系统可靠性分析模型,通过马尔科夫过程计算得到系统各状态的概率,利用通用生成函数评估系统稳态和瞬态的可靠性指标。通过算例分析,验证方法的正确性和可行性。     

舰船电子设备远程维修系统架构研究

该文提出了基于军用互联网构建舰船电子设备远程维修系统的总体设计方案,并讨论了系统中关键模块的实现方法。该系统以信息的流动代替维修专家的流动,能够实现舰船电子设备远程故障诊断和维修,缩短维修时间、节约维修开支。     

大型船舶钨极氩弧重熔工艺应用

疲劳破坏是船体结构的主要破坏形式之一。改进结构节点的设计和施工工艺,可保证船体结构中受交变载荷作用的构件有足够的疲劳寿命。钨极氩弧(Tungsten Inert Gas, TIG)重熔是改善结构节点焊后疲劳强度的有效方法。与目前船上常用的几种改善疲劳强度的方法进行分析对比,对TIG重熔工艺的重要性进行充分论证,获得实施TIG重熔工艺的技术标准和操作要点。TIG重熔工艺不仅改善结构节点疲劳强度,而且为建造具有较长疲劳寿命的大型船舶找到一个行之有效的方法,可产生良好的经济和社会效益。     

复合材料船体结构可靠性分析

本文综合考虑了复合材料本身及外载的多处不确定因素，首次对复合材料船全校 强度、可靠性问题进行了较全面的研究，考虑了多种失效模式并对复合材料结构本身的各随机变量的分布规律进行了统计分析。给出了一硬壳式下班钢艇的实例计算并分析了各种参数对船体结构可靠性的影响，得到了一些很有实际应用价值的结论。     

A study on reliability-based inspection planning – Application to deck plate thickness measurement of aging tankers

In order to conduct a timely and effective inspection to avoid the ultimate failure of deck plate, a reliability-based procedure for inspection planning is introduced. A review of the uncertainties in deriving the capacity of deck plate and through life degradation effects on tanker structural integrity is given. Using the Latin Hypercube sampling method to perform the Monte Carlo Simulation, the time-variant failure probabilities of deck plate are computed, then compared with target values. Based on the comparison, the time for thickness measurement of deck plate is predicted. A total of 1080 cases for nine sample tankers are analyzed to illustrate the procedure, including sensitivity and parametric studies. This paper is a sequel to the preceding paper [6], where a semi-probabilistic approach is presented to assess the time-variant ultimate strength of aging tanker’s deck plate considering corrosion wastage.     

A simplified method for nonlinear failure analysis of stiffened plates

This paper shows that the application of pre-determined failure equations, derived from nonlinear finite element analyses, is effective in determining failure of structural components in a simpler linear finite element analysis. An analysis method is presented which is called simplified failure analysis. The first step of this method is the nonlinear determination of a component's failure limit. Next, a linear coarse-meshed finite element model of the component is analyzed under the failure load determined in the previous step. The resulting linear stress distribution is a ‘representative failure stress’ for the component because it is in equilibrium with the applied failure load. This ‘failure stress’ is then used in simpler linear analysis to provide a representative failure limit. This method is verified by an analysis of a structural grillage.     

DEA方法在电子对抗装备软件综合评价中的应用研究

针对电子对抗装备软件综合评价中四种不同的群体,建立装备软件综合评价的指标体系,并根据其特点,将模糊综合评价方法和DEA方法结合起来,建立了电子对抗装备软件综合评价和装备软件组织与设计开发方案选择模型,最后给出一个实例验证了模型的正确性。     

Strength reliability analysis of stiffened cylindrical shells considering failure correlation

The stiffened cylindrical shell is commonly used for thepressure hull of submersibles and the legs of offshore platforms.There are various failure modes because of uncertainty with thestructural size and material properties, uncertainty of the calculationmodel and machining errors. Correlations among failure modesmust be considered with the structural reliability of stiffenedcylindrical shells. However, the traditional method cannot considerthe correlations effectively. The aim of this study is to present amethod of reliability analysis for stiffened cylindrical shells whichconsiders the correlations among failure modes. Firstly, the jointfailure probability calculation formula of two related failure modesis derived through use of the 2D joint probability density function.Secondly, the full probability formula of the tandem structuralsystem is given with consideration to the correlations among failuremodes. At last, the accuracy of the system reliability calculation isverified through use of the Monte Carlo simulation. Result of theanalysis shows the failure probability of stiffened cylindrical shellscan be gained through adding the failure probability of each mode.     

基于模糊综合评判的电子对抗装备作战运用训练效果评估

从训练评估指标的构建要求入手,建立了电子对抗装备作战运用训练效果评估指标体系,运用模糊综合评判法,建立了电子对抗装备作战运用训练效果评估模型,最后通过实例验证,证明了该方法的可行性。     

大型结构系统可靠性分析方法研究

结构系统的可靠性评估是结构设计的一个重要研究内容,而极限状态函数的建立是进行可靠性评估的基础.但是,大型结构系统的极限状态函数极为复杂,响应面法用简单的多项式进行模拟的精度较低,导致误差较大.文章提出用神经网络替代多项式来拟合复杂的极限状态函数,形成所谓的神经网络响应面.然后,基于塑性极限理论,文中提出了不依赖于失效模式的极限状态函数表达形式及采用ICP对该极限状态函数进行计算的方法.最后,依照拟合得到的神经网络响应面,给出了大型结构系统失效概率的方法.通过两个算例计算并和其它方法进行比较,表明该方法的计算精度较高,而计算时间大大降低.     

Design of bridges against ship collisions

The paper outlines a rational design procedure for bridge piers and pylons against ship collision impacts. Firstly, a set of risk acceptance criteria are proposed. This is followed by a mathematically based procedure for calculation of the probability of critical ship meeting situations near the bridge, and the probability of ship collision accidents caused by human errors as well as technical errors. This first part of the paper leads to identification of the largest striking ship, “design vessels”, a given bridge pier must withstand without structural failure in order for the bridge connection to fulfil the risk acceptance criteria. The final part of the paper is devoted to an analysis of the needed impact capacity for the bridge pylons and piers exposed to ship bow impact loads from these “design vessels”. For a number of different ship types and different tonnage merchant vessels, load – displacement relations for ship bow collisions against rigid walls are derived. Based on these comprehensive numerical results, a new empirical relation is derived which is suited for design against bow collisions. This expression for maximum bow collision forces is compared with a previously published expression for ice-strengthened ships and with existing standards for assessment of bow crushing forces. It is shown that there is need for an update of these existing standards. For design of piers and pylons against local impact pressure loads, a pressure - area relation for bulbous bow impacts is derived.