风险视角下的动车组部件多级非完美维修策略

为了降低动车组部件在一个寿命周期内的维修总成本,以动车组五级修程时需要更换的部件为研究对象,基于现行的分级检修制度,提出一种动车组部件多级非完美预防性维修策略.以故障对动车组运行安全和对动车组晚点的影响以及故障维修难易程度作为故障风险的评价指标,使用层次分析法和评分法量化评价部件的故障风险.将动车组部件非完美维修方式划...     

考虑故障风险的动车组部件预防性维护优化建模*

为了减小动车组部件的故障危害,以动车组四级修程时进行更换的部件为研究对象,通过引入故障风险因子,并结合我国动车组现行的多级非完美维护制度,建立一种考虑故障风险的动车组部件两级非完美顺序预防性维护模型。在顺序预防性维护模型的基础上,将维护方式进一步划分为初级维修和高级维修两种,通过经济性分析确定每一次维护的具体方式。对影响部件故障风险的各因素进行评分和权重,克服了以往模型仅考虑部件故障停机损失,忽视部件故障导致的其他危害的不足。以故障里程服从威布尔分布的部件进行算例分析,仿真结果表明,与不考虑故障风险制定出的预防性维护计划相比,该模型更具经济性和安全性,可为动车组部件的维护决策提供理论支持。     

考虑动态折旧成本的动车组部件预防性维修决策模型

为研究部件自身价值变化对其维修决策的影响,以动车组四级修时需更换的部件为研究对象,结合我国动车组现行的多级非完美维修方式,建立了一种考虑动态折旧成本的动车组部件两级非完美预防性维修优化模型,该模型以动车组部件的等效役龄计算其相应的折旧成本。进一步研究了部件折旧成本与故障率变化相关联的维修决策方法。研究结果表明,与不考虑部件折旧成本的维修模型相比,该模型兼顾了部件的生产运行和维修活动对维修决策的影响,能够更好地平衡预防性维修成本和故障维修成本,使模型更具维修经济性。     

基于可靠性的列车预防性多梯度机会维修策略

针对现有城市轨道列车车辆检修策略中的过维修和欠维修，以及机会维修单一等问题，提出一种基于可靠性的预防性多梯度机会维修策略。通过分析历史故障数据，对不同部件设置不同等级的机会维修阈值，建立了灵活的多梯度机会维修策略。在维修策略中引入故障率递增因子和役龄回退因子，采用故障性维修、预防性维修、多梯度机会维修和预防性更换相结合的维护方式，得出总成本最低的最佳预防性维修周期和维修次数。以某城市轨道列车检修为例进行实例仿真表明，相比单部件顺序维修策略，所提基于可靠性的多梯度机会维修策略可有效减少停车次数、节省维护费用、提高运营效率，从而为城市轨道列车的预防性维修提供科学依据和理论参考。     

基于维修优先级与寿命分布的多部件系统竞争式维修策略EI北大核心CSCD

针对多部件系统中各部件维修优先级不同的情况,提出了基于寿命分布的非集中式维修策略。采用异构多部件系统的竞争式维修模式,在已知部件寿命分布的情况下,建立了一种(m,N)维修模型。建模过程中充分考虑部件维修优先级的不同,对高维修优先级部件,采用修复性维修和预防性维修;对低维修优先级部件,采用成组维修。以全周期的最低维修费率为目标,通过计算不同部件的失效次序统计量,对参数进行优化,进而得到最优维修策略。通过数值算例验证了维修策略的有效性,并对参数敏感度进行了分析。     

基于维修优先级与寿命分布的多部件系统竞争式维修策略

针对多部件系统中各部件维修优先级不同的情况,提出了基于寿命分布的非集中式维修策略。采用异构多部件系统的竞争式维修模式,在已知部件寿命分布的情况下,建立了一种(m,N)维修模型。建模过程中充分考虑部件维修优先级的不同,对高维修优先级部件,采用修复性维修和预防性维修;对低维修优先级部件,采用成组维修。以全周期的最低维修费率为目标,通过计算不同部件的失效次序统计量,对参数进行优化,进而得到最优维修策略。通过数值算例验证了维修策略的有效性,并对参数敏感度进行了分析。     

考虑非完美维修的实时剩余寿命预测及维修决策模型

准确的剩余寿命预测是对设备进行预防性维护维修决策的关键。利用随机滤波理论,基于当前时刻及之前的历史状态监测信息,由已知的设备初始寿命分布函数建立非完美维修策略下的实时剩余寿命分布函数预测模型。同时考虑非完美维修效果与时间相关性,提出一种以平均剩余寿命为阈值的非完美预防性维护及更换的维修策略,建立了以系统的预防性维护及预防性更换阈值为优化变量和最小化平均维护维修费用为目标函数的优化模型。采用微粒群算法进行优化求解,得到系统最佳的预防性维护及预防性更换阈值,并使系统长期运行平均费用率最低。以初始寿命符合威布尔分布的疲劳裂纹为例,验证了该实时剩余寿命分布预测方法及非完美维护维修策略的可行性。     

设备可靠性与维修决策关系研究

根据设备可靠性理论 ,在对设备故障类型及其分布曲线进行分析的基础上 ,提出了以设备故障率分布情况为依据来选择定期预防维修方式或状态监测维修方式的维修策略 ,该策略有助于实现设备寿命周期费用最优化。     

考虑非完美维修的多部件系统劣化状态空间划分建模

为了进一步深入研究考虑非完美维修效果的建模方法,利用劣化状态空间划分思想对考虑非完美维修的多部件系统视情机会维修策略进行了统一建模。针对多部件系统,考虑非完美维修效果,制定了基于周期检测的视情机会维修策略,建立了联合劣化状态空间划分模型,给出了所有维修需求组合及其概率计算通式,推导了联合稳态概率密度函数。通过数值实验验证了上述模型及联合稳态概率密度函数求解的正确性,同时定性分析了该建模方法对研究相同多部件系统维修优化建模的有效性,为后续的维修优化研究奠定了基础。     

基于仿真的多部件设备机会维修多目标决策优化方法

提出一种基于仿真的多部件设备机会维修多目标决策优化方法，考虑了多种维修方式、多种机会维修策略、非预期故障的随机持续时长和成本以及随机的预防性维修时长，利用蒙特卡洛仿真计算系统可用度和总成本，多目标粒子群算法进行求解最佳维修方式。将该方法应用到电子组装线的某生产设备，结果显示，同时考虑了随机故障和预防性维修的机会维修策略具有更优的Pareto前沿，能够进一步优化系统可用度与系统总成本，并对可用度和总成本的随机分布进行了分析。     

考虑客流分布的动车组部件预防性维护决策

为探究客流分布不均的动车组部件维护策略的经济性,引入多项式拟合方法对波动客流进行分段量化,并提出客流分布不均的部件差异化停机损失成本函数,进而结合加速失效模型建立了以可靠度为约束条件的部件维护策略动态调整方法,通过对部件延迟维护可靠度阈值进行敏感性分析,确定了经济性最佳的维护策略调整方法.研究结果表明,考虑客流分布的维...     

Optimizing opportunistic preventive maintenance strategy for multi-unit system of CNC lathe

Due to the many components in the multi-unit system (i.e., CNC machine tools), the existing preventive maintenance (PM) strategies conducting independent PM for every component are time-consuming and waste unnecessary maintenance and downtime costs. Hence, this paper introduces the idea of opportunistic maintenance into the PM and proposes an opportunistic imperfect PM approach, which is a more realistic PM policy for a multi-unit system. In this approach, the effect of PM is assumed to be imperfect to correct the failure rate of each unit. According to the corrected failure rate function, the imperfect PM strategy of a single unit is optimized by minimizing the proposed unit maintenance cost rate under the limitation of minimum reliability. Then, these independent imperfect PM strategies for units are rescheduled by the proposed opportunistic PM strategy under the condition of judging the reliability OM threshold of units. We further optimize the opportunistic PM strategy by minimizing the total maintenance cost. Finally, the advantage of our approach is verified by the case study of 18 CNC lathes.

     

直升机金属动部件的寿命管理

针对某型直升机动部件承受高频低幅振动载荷的特点,探讨安全寿命和损伤容限相结合的寿命控制方法。以直升机的金属主桨叶为例,采用飞行空测载荷数据编制的实测统计载荷谱,通过Miner线性累积损伤理论计算得到裂纹形成寿命与风险率的关系。同时考虑裂纹扩展寿命对降低风险率的贡献,通过断裂力学分析计算出应力强度因子、损伤容限临界裂纹尺寸,建立主桨叶损伤容限分析的工程计算模型,得到裂纹扩展寿命(检查周期)与风险率的关系。     

A study on reliability centered maintenance planning of a standard electric motor unit subsystem using computational techniques

The design and manufacture of urban transportation applications has been necessarily complicated in order to improve its safety. Urban transportation systems have complex structures that consist of various electric, electronic, and mechanical components, and the maintenance costs generally take up approximately 60% of the total operational costs. Therefore, it is essential to establish a maintenance plan that takes into account both safety and cost. In considering safety and cost limitations, this research introduces an advanced reliability centered maintenance (RCM) planning method using computational techniques, and applies the method to a standard electric motor unit (EMU) subsystem. First, this research devises a maintenance cost function that can reflect the current operating conditions, and maintenance characteristics, of components by generating essential cost factors. Second, a reliability growth analysis (RGA) is performed, using the Army Material Systems Analysis Activity (AMSAA) model, to estimate reliability indexes such as failure rate, and mean time between failures (MTBF), of a standard EMU subsystem, and each individual component Third, two optimization processes are performed to ascertain the optimal maintenance reliability of each component in the standard EMU subsystem. Finally, this research presents the maintenance time of each component based on the optimal maintenance reliability provided by optimization processesand reliability indexes provided by the RGA method. This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim Myung-Won Suh is a professor of Mechanical Engineering. During 1986–1988, he worked for Ford motor company as researcher. During 1989–1995, he worked in the technical center of KIA motors. He earned a BS degree in Mechanical Engineering from Seoul National University and an MS degree in Mechanical Engineering from KAIST, South Korea. He obtained his Doctorate at the University of Michigan, USA, in 1989. His research areas include structure and system optimization, advanced safety vehicle and reliability analysis & optimization. Chul-Ho Bae is a PhD candidate at Sungkyunkwan University in Suwon, South Korea. He ac-complished fellowship work as researcher at Mississippi State University, USA, in 2003 and 2005. He worked in Institute of Advanced Machinery and Technology (IMAT) as a Research Assistant in 2004. He was a part time Lecturer in computer aided Mechanical Engineering of Ansan College of Technology, Suwon Science College, and Osan College during 2004–2005. He took a BS Degree in Mechanical Design and an MS Degree in Mechanical Engineering from the Sungkyunkwan University. His research interests include computer aided engineering, reliability engineering, and optimization.     

Reliability and fatigue life evaluation of railway axles

The axle is one of the most important components of a rail vehicle which transmits the weight of the vehicle to the wheels, meets the vertical and horizontal loads formed during static and dynamic moving, and carries the driving moment and braking moment. The prediction of fatigue failure of axles plays an important role in preventing fatigue fractures. Varying loads on components lead to cumulative failure in the mechanism. In this study, failures in axles of rail vehicles serving the Istanbul Transportation Co. have been investigated. Statistical evaluation of real life values has been performed by taking into account the kilometer and load cycle. Equivalent stresses have been used to derive life equations and diagrams by using one of the cumulative life theories known as the Palmgren-Miner method. Finally, theoretical and practical Wohler diagrams S-N (σ-N: stress-life) have been plotted to reveal error calculation.     

电动车组系统部件预防性维修可靠度的研究

针对电动车组系统部件的预防性维修,引入役龄回退因子的概念,建立预防性维修前后故障率的递推关系,对预防性维修后的可靠度进行了预估,为电动车组的修程优化提供了改进方向.     

加固显控终端散热设计

以全加固显控终端散热设计为例,为大功耗全加固电子产品提出完整的散热设计理论及方法,通过优化设计以及仿真分析,使产品整体可靠性得到大幅提升。研究表明,电子通讯设备失效大多是电子元器件过热引起的,在全加固电子设备中,由于温度因素造成的故障率也达到了很高的数值。所以合理的热设计是提高电子设备可靠性,降低产品维护费用,提高核心竞争力的关键技术,对降低全加固电子设备的故障率具有很大的帮助。     

考虑修复非新的多组件DTS设备的状态维护建模

针对设备同时面临内部状态衰退和外部随机冲击的特性,基于状态维护和DTS建模理论,以Gamma过程模拟各组件的内部衰退,以整合多组件内部衰退状态的非齐次泊松过程模拟设备整体的外部冲击影响,构建了基于状态监测的设备内外交互型衰退模型。在此基础上,采用对数正态分布构建基于状态的组件修复非新模型,以有效区分各组件的状态修复效果,进而通过引入综合状态参数,建立了针对多组件设备的“综合状态阈值-变周期检测”型状态维护策略与决策模型。基于蒙特卡罗仿真的算例分析表明,该状态维护模型可有效表征多组件DTS设备的实际衰退及维护过程。