基于蒙特卡洛仿真的动态故障树分析

针对基于马尔可夫链的动态故障树分析方法的局限性,把蒙特卡洛方法用于动态故障树分析。研究了动态故障树分析的蒙特卡洛仿真法并给出了仿真的具体步骤,然后利用实例对给定的动态故障树进行了蒙特卡洛仿真,并把仿真结果与精确解进行了比较。结果表明,把蒙特卡洛法用于动态故障树分析是有效的。     

A fuzzy Bayesian belief network for safety assessment of oil and gas pipelines

Safety assessment of oil and gas (O&G) pipelines is necessary to prevent unwanted events that may cause catastrophic accidents and heavy financial losses. This study develops a safety assessment model for O&G pipeline failure by incorporating fuzzy logic into Bayesian belief network. Proposed fuzzy Bayesian belief network (FBBN) model explicitly represents dependencies of events, updating probabilities and representation of uncertain knowledge (such as randomness, vagueness and ignorance). The study highlights the utility of FBBN in safety analysis of O&G pipeline because of its flexible structure, allowing it to fit a wide variety of accident scenarios. The sensitivity analysis of the proposed model indicates that construction defect, overload, mechanical damage, bad installation and quality of worker are the most significant causes for the O&G pipeline failures. The research results can help owners of transmission and distribution pipeline companies and professionals to prepare preventive safety measures and allocate proper resources.     

尾气冷却器列管泄漏原因分析与解决措施

通过查找冷却器列管泄漏原因,对设备本体进行解体检查,全面分析了列管泄漏原因,采用新方法 FAT树分析,采取解决途径与预防措施,确保设备稳定可靠运行。     

Risk analysis using fault-tree analysis (FTA) and analytic hierarchy process (AHP) applicable to shield TBM tunnels

In this paper, the potential risk of undesirable events occurring during tunneling with application of a shield tunnel boring machine (TBM) method is discussed along with the risk analysis which can systematically assess overall risk levels. Potential risks and typical scenarios pertaining to shield TBM tunnels have been investigated based on previous case histories and correspondence with experts. The relevant risks from undesirable events were categorized into four groups: cutter-related malfunction, machine blockage or hold-up, mucking problems that hinder transporting excavated materials, and segment defects. A fault-tree set was constructed by grouping risk factors (or causes) into geological, design and construction/management factors. Risk analysis was performed by adopting fault-tree analysis (FTA) and an analytic hierarchy process (AHP) with consideration of the probability and impact of the risks. In addition, the proposed method was reliably validated by comparison with field observation, and thus indicates its applicability to risk management for shield TBM tunneling.     

西门子公司SIWAREX FTA全集成称重控制系统

采用西门子公司SIWAREX FTA称重模块可以代替称重仪表接收称重传感器输出的mV信号,从而与PLC构成全集成称重控制系统,它具有称重控制设备一体化、结构简单、系统集成度高等优点,代表了衡器发展方向.     

基于故障树分析法的拆除爆破飞散物事故风险分析

为充分控制拆除爆破工程中爆破飞散物对周边环境的影响,建立了以故障树分析法为理论基础,以拆除爆破工艺流程为主线的爆破飞石故障树模型。以拆除爆破中各个工艺单元为基本事件,同时通过子系统设定、系统执行设定和系统独立设定,将分析过程控制的更加严谨和合乎实际。通过最小割集-概率重要度分析指出有效控制部分基本事件使其不发生可以大大提高系统安全状态;通过最小径集分析和结构重要度分析指出了技术人员特别是高级技术人员对拆除爆破飞散物事故控制至关重要的作用。     

某金属矿山采场爆破系统的模糊FMECA评价

金属矿山采场爆破作业包括七大事故模式,即早爆、拒爆、迟爆、爆破飞石、爆破震动、冲击波、炮烟中毒,在对这些危险有害因素进行初步分析的基础上,运用模糊FMECA方法对某金属矿山爆破系统进行综合评价,对危险度高的拒爆事故模式建造了事故树,并根据评价和分析的结果提出了相应的预防措施,为金属矿山爆破安全管理提供一定的依据.     

基于HoR的可靠性配置方法研究

运用HoR(House of Reliability)思想,将故障树分析(FTA)、失效模式影响及危害性分析(FMECA)整合于质量功能配置(QFD)中,建立可靠性配置流程:对系统可靠性指标进行分配,解决了传统方法过度依赖于主观打分的问题;在此基础上,建立以顾客可靠性满意度最大和配置成本最低为目标的模型,将可靠性指标配置到具体的工程技术特征上。并以数控车床电主轴为例,对模型的有效性进行了验证。     

脚踝康复机器人的可靠性评估

本文首先对脚踝康复机器人的结构和功能进行分析,描述脚踝康复机器人各功能单元的相互依赖关系。建立脚踝康复机器人故障树,通过故障树的定性和定量分析,得到故障树底事件的相对概率重要度,从而确定关键零部件及其故障模式。建立脚踝康复机器人的可靠性数学模型及可靠性框图,并计算得到脚踝康复机器人系统基本可靠度。本文探索了一种比较实用、高效的脚踝康复机器人可靠性评估方法,为脚踝康复机器人可靠性设计提供依据。     

焊接结构承压管道有限元与可靠性分析

针对工业设备上常见的焊接结构承压管道,应用模糊灰关联FTA安全系统工程理论,以水火管锅壳锅炉为例,通过对失效致因和故障模式的研究,建立以焊接结构承压管道失效为顶事件的模糊灰关联FTA模型,利用有限元法建立焊接结构承压管道模型辅助分析对其更深层次的系统性影响,并综合考虑工况环境、外部载荷等多因素耦合作用,确定导致事故的主要潜在风险项,为承压管道设备安全保障活动的经济决策提供依据。研究结果表明,以水火管锅壳锅炉的“焊接结构承压管道”失效故障模式的发生概率约为8.19%,系统的可靠度约为91.81%。