特种车辆方舱结构设计和优化

特种车辆方舱是一种在现代军队中应用较多也是较为广泛的一种装备,特种车辆方舱凭借其良好的通用性和机动性广泛活跃于指挥、通信、后勤保障等多个领域,特种车辆方舱作为机动式的工作平台其能够完成人员和电子通信、指挥设备的搭载。受制于空间和结构的限制在特种车辆方舱的设计过程中应当尽量通过通用化、规范化的标准化设计来构建通用化、系列化和模块化的用以提高特种车辆方舱零部件的互换性以及特种车辆方舱的设计、生产效率,从而有效地增强特种车辆方舱的生存和维修的效率。本文在分析特种车辆方舱特点的基础上对特种车辆方舱设计中的要点进行分析阐述。     

不确定环境下复杂机械装配系统设备维修方法

为保障不确定环境下复杂机械装配系统的连续性并降低其维修成本,提出一种以马尔可夫决策理论为基础的设备维修策略动态选择方法。在综合考虑系统运行成本、缓冲库存成本、设备维修成本及停机损失成本的基础上,构建了装配系统可靠性成本模型。该模型以带有中间缓冲区的二级装配系统为研究对象,以设备状态和缓冲库存量为自变量,以可靠性成本为目标函数。分析了装配系统的不同运行状态,利用模拟退火算法和模糊非线性混合整数目标规划对可靠性成本模型求解,制定装配系统最优维修方法。该方法降低了装配系统停机时间,减少了设备维修次数,可为生产线设计和维修计划的制定提供依据。最后,通过算例分析验证了模型的有效性和可行性。     

基于光纤光栅的高速公路车辆检测系统研究

我国的高速公路发展迅速,运行车辆数量也与日俱增,其中车辆检测技术对于良好的运营管理至关重要。基于此,该文研究了一种基于光纤光栅的车辆检测系统,根据车辆通过时检测区域光纤光栅中心波长的偏移量、变化时间差和变化位置等采集信息,可计算得出待测车辆车重、轴距、车型、车速等车辆运行参数,通过建立标准检测数据库可对检测数据进行校准和优化。     

某特种车辆静水闭舱作业舱室内有害气体测试方法及效果评价

目的根据某特种车辆产品在生产过程中的实际需求,建立特种车辆静水闭舱作业过程中舱室内有害气体的测试方法,并进行效果评价分析。方法根据被试对象的结构布局和被测部位的重要性,分别选择车辆的驾驶员位、车长位和载员位进行布放测试设备,利用测试设备各相应传感器进行自动连续采样、分析、记录有害气体的试验数据,并按相关标准要求进行计算。结果按照相关标准中的要求进行试验测试,本次试验,被试特种车辆在静水闭舱作业过程中,其舱室内驾驶员位、车长位和载员位有害气体浓度的MAC(最高容许浓度)、TWA(时间加权平均容许浓度)以及STEL(短时间接触容许浓度),均符合GJB5834-2006标准限值的要求。结论该测试方法能够满足特种车辆静水闭舱作业过程中舱室内有害气体的测试需求。     

浅谈合理规划维检修管理

针对石油管道场站设备数量运行强度等问题,以设备精度管理作为管理方针,做到完善设备功能,提升设备精度的维检修标准。全面加强合理规划维修和检修管理,以设备受控性、工作高效性、维检修零缺陷性为管理目标,严格科学的开展设备运行定期分析研究工作、建立可靠的管理体系、定期对相关技术人员进行统一培训、完善维检修管理和标准化维护管理的标准性。通过设备监控、设备保障、维检修现场执行等具体情况,提升设备合理规划维护检修管理机制的管理理念和管理模式,积极采用各种手段和措施推进设备维护检修管理进度,以提高设备运行质量和降低维检修成本作为最终要求,以此保证各种相关设备在工作时安全高效运行,并且优化大型设备整体管理流程,使企业经济效益最大化提升。     

浅析故障诊断技术在矿山机电工作的应用

故障诊断技术被广泛应用于矿山机电设备维修中,它对合理安排矿山生产、设备维修工作,设备使用寿命、减少设备运行与维修成本、提高设备使用效率、追求设备的最小投入、创造最大利润起到非常重要的作用,本文拟对故障诊断技术的主要内容和常见应用形式进行分析和探讨,可为矿山企业机电设备故障诊断技术提供参考和借鉴。     

闭式软化水处理设备用盐沉滞问题处理

通过对闭式软化水处理设备用盐沉滞问题的调查、分析、方案制定及实施,解决了存在的问题,降低了运行成本,提高设备效率和维修质量。     

注重2X330-3挖掘机的维护保证安装工程顺利施工

挖掘机在油田企业施工中见一种觉的特种车辆,日立2X330-3挖掘机也广泛应用在油田企业,它采用了五十铃6HKI电喷发动机,本文将时论该系统的维修理论,对故障的分析维修方法进行论述.     

矿山机电设备的管理及诊断探讨

合理安排矿山机电设备管理、设备维修、延长设备使用寿命、减少设备运行与维修成本、提高设备使用效率、追求设备的最小投入创造最大利润起到非常重要的作用,本文通过分析故障诊断技术的内涵,总结研究了矿山机电维修的几种故障诊断方法,为矿山企业的发展提供了参考和接鉴。     

矿山机电设备的管理及诊断探讨

合理安排矿山机电设备的管理、设备维修、延长设备使用寿命、减少设备运行与维修成本、提高设备使用效率、追求设备的最小投入创造最大利润起到非常重要的作用,本文通过分析故障诊断技术的内涵,总结研究了矿山机电设备维修的几种故障诊断方法,为矿山企业的发展提供了参考和借鉴。     

车下设备悬挂刚度对车辆平稳性影响

为分析车下设备悬挂刚度对车辆平稳性的影响,通过对某型动车的车体有限元模型进行模态计算,并利用多体动力学软件SIMPACK的接口模块FEMBS建立该动车的刚柔耦合系统动力学模型,研究不同的设备悬挂刚度对车体与设备的耦合振动影响。通过刚性与弹性两种不同的联接方式对的比分析可知,弹性联接方式能够对车体的弯曲振动起到抑制作用,由此大大降低设备对车体振动的影响。刚度优化仿真结果表明：车下设备悬挂刚度的不同对车辆的平稳性指标有着重要的影响。     

国泰化工60000m3／h空分设备配置分析

空分设备是煤化工项目的一个重要装置,空分设备的稳定运行是煤化工项目正常运行的基础,而空分设备工艺流程的正确选择、配套设备的合理选型是空分系统稳定运行的基础。文章从投资成本、能耗、运行维护成本和运行稳定性方面分析空分设备供应商、工艺流程和空压机组的选择依据,以求为空分系统的稳定、低能耗运行打下基础。     

智能制造系统AGV小车及缓冲区容量仿真优化

具有MHS(material handling system)的智能制造系统AGV(automated guided vehicle)小车及缓冲区最大容量配置优化,属于典型的非线性整数规划问题。由于约束无法用封闭形式表达,因此较难获得问题的精确解。为此,本文提出了仿真优化的方法以获得问题的近似解。首先,对AGV小车及缓冲区最大容量配置优化问题进行了描述;其次,基于Em plant平台建立了具有MHS的智能制造系统仿真模型;然后,基于不同的优化目标,提出了3种仿真优化方法;最后,通过仿真试验对上述3种方法进行了分析与比较。分析表明,本文提出的方法及优化结果,可为企业配置AGV小车及缓冲区最大容量提供决策支持。     

Maintenance Strategies and Failure‐Cost Model for Medical Equipment

This paper proposes a mathematical maintenance model that analyses the effect of maintenance on the survival probability of medical equipment based on maintenance history and age of the equipment. The proposed model is simulated in Scilab using real data extracted from maintenance history of anaesthesia machine from Draeger. The analysis using survival approach reveals that conducting preventive maintenance on the selected medical equipment had a positive impact on survival of equipment. The model is then used to analyse the cost of maintenance scenarios, and an appropriate scenario is proposed for anaesthesia machine. A new failure‐cost model is developed, which may be used to calculate the number of failures of equipment and the annual maintenance cost. The proposed models may be used as a planning tool for selecting maintenance strategies for various medical equipments. Copyright © 2014 John Wiley & Sons, Ltd.     

Optimal preventive maintenance strategy for leased equipment under successive usage-based contracts

In the context of equipment leasing, maintenance service is usually bundled with the leased equipment and offered by the lessor as an integrated package under a lease contract. The lessor is then responsible to prescribe an effective maintenance policy to keep the equipment operational in an economical way. This paper investigates upgrade and preventive maintenance (PM) strategies for industrial equipment during successive usage-based lease contracts with consideration of a warranty period, from the lessor's perspective. The accelerated failure time model and age reduction model are adopted to capture the effect of usage rate and imperfect PM/upgrade on the equipment reliability, respectively. More importantly, since equipment usage rates may vary across different lease contracts, this study develops an age correspondence framework to characterise usage rate shifts between successive lease periods. The optimal upgrade degree and the optimal number and level of PM actions are progressively updated for each upcoming lease period to minimise the total expected lease servicing cost, by considering the usage rate and maintenance implementation history. Numerical studies show that under given cost structures, periodical PM activities within each lease period tends to outperform the pre-leasing upgrade actions, though both of them can reduce the lease servicing cost.     

Effects of maintenance policy on an imperfect production system under trade credit

The traditional production model development assumed that all products are perfect quality and did not consider maintenance, which is far from reality. In practice, the production process may shift randomly from an in-control state to an out-of-control state during a production run, i.e. process deterioration. This paper considers both preventive maintenance and corrective maintenance which are used to increase the system reliability. The objective of this paper is to determine the optimal production run time and maintenance frequency while minimising the total cost under process deterioration and trade credit. This paper develops a theorem and an algorithm to solve the problem described, provides numerical analysis to illustrate the proposed solution procedure, and discusses the impact of various system parameters. A real case of hi-tech manufacturer is used to verify the model. It predicts a 10.36% decrease in total cost if the preventive maintenance decision is considered.     

Failure analysis for power car wheels based on contact positions and tread slope

During service operation, the thermal cracks and shelling at power car wheel are initiated before a regular profiling of railway wheel. The damaged railway wheel is reprofiled prior to regular inspection and the maintenance cost for the railway wheel is sharply increased. Therefore, it is necessary to analyze and understand the damage mechanism of power car wheel in order to reduce maintenance cost.In the present paper, to analyze the damage cause and reduction for the power car wheel with tread brakes, the observations of by replication test was performed and fracture characteristics depend on contact zones are carried out. Contact stress is analyzed with respect to the wheel tread slope and contact positions. The result shows the zone between tread center and wheel rim demonstrated white layer by higher hardness and lower fracture toughness and faster crack growth rate in view point of fracture mechanic characteristics. The 1/20 of wheel tread slope can effectively mitigates surface damage of power car wheel.     

Multi-phase preventive maintenance policy for leased equipment

This paper proposes a multi-phase preventive maintenance (PM) policy for leased equipment by combining the advantages of both periodic PM and sequential PM. The lease period of the equipment is divided into multiple PM phases. The PM activities within each phase are performed periodically with the convenience of implementation, while the frequency of PM for each phase is different and it gives a gradual increase because of the imperfect effect of PM. A multi-phase PM model is built up based on the age reduction method for imperfect PM with the penalty for equipment failures and overtime of repair involved. The optimal PM intervals for every PM phases are achieved by minimising the cumulative maintenance cost throughout the lease period from the perspective of the lessor. Numerical example shows that the cumulative maintenance cost under the proposed multi-phase PM policy is lower than that under periodic PM policy.     

液化天然气铁路罐车设计及试验

目的 本文通过对液化天然气铁路罐车的设计及试验验证进行研究，为LNG铁路罐车的应用提供参考。方法 介绍液化天然气铁路罐车的技术参数确定和结构组成，采用CAD、FEM技术对罐车的结构进行设计研究及仿真分析，通过铁路静强度和冲击试验、低温性能测试等手段验证罐车的力学性能和真空绝热指标。结果 液化天然气铁路罐车轴质量为23 t、载质量不超过41 t，在最高运行速度120 km/h时能够安全运行，每天的静态蒸发率(液氮)为0.08%，维持时间(液氮)达到92 d。结论 液化天然气铁路罐车的技术参数及性能指标达到了设计文件和相关标准的要求。