浅谈8K电力机车在役车轴超声波探伤方法

分析了8K电力机车在役车轴疲劳裂纹产生原因,提出了超声波探伤方法,并介绍了疲劳裂纹波形特点和疲劳裂纹定量影响因素。     

故障树分析法在汽油发动机电控系统故障诊断中的应用

发动机电控系统是由传感器、执行器和控制单元三部分组成的,发动机正常运转过程是以控制系统为基础,通过不同信号的采集、处理和传输来实现发动机进气、喷油、点火等环节的有序进行。一旦发生故障,则症状的界限模糊。通常情况下系统故障发生在某个部件的具体位置,其他位置表现的状态正常,因此当发生局部故障时,最好是查清故障的具体位置然后作出相应的故障处理策略,不然更换整体部件虽然也排除了故障但是造成了很大程度的资源浪费。本文具体的阐述了故障树分析法在汽车发动机电控系统故障诊断过程中的应用研究,并通过实际的案例分析证明了故障树分析法的实用性和有效性。在未来故障诊断的相关研究中可以不断深化新型诊断技术的研究和开发。     

基于USB的机车故障检测记录仪数据传输技术

针对当前机车故障检测记录仪所存故障的快速提取需求，结合USB接口的结构、特点，介绍基于Cypress EZ-USB2131的USB软硬件系统的开发方法，阐述该系统在机车故障检测记录仪中的应用。从实际的检测记录仪装车运行效果可以看出，USB接口技术能够为车载设备信息的提取提供高速可靠的连接，满足实际需求。     

隧道及地下工程渗漏水诱发原因与防治对策

渗漏水防治是隧道及地下工程全寿命周期内必须面对的难点和挑战。为此，综述了隧道及地下工程渗漏水防治实践与研究的最新进展，探讨了渗漏水类型及诱发原因、服役期渗漏水检测方法及原理、设计施工阶段渗漏水预防的理念及技术措施、施工运营期渗漏水处治的内涵及方法，展望了值得重视的未来发展及研究方向。研究结果表明：隧道及地下工程渗漏水可按照渗漏水发生部位、形式、水量分为不同类型；渗漏水诱发原因极其繁杂，涉及水文地质条件、设计、施工、使用环境等多个方面；服役期渗漏水快速无损检测法的精度还有待提高，现阶段应与传统检测法相辅相成，其未来发展趋势为智能化、轻巧化和实时监控预警；渗漏水预防的核心在于防排水设计原则合理、防排水系统施工质量可靠、防水材料强度及耐久性满足要求；渗漏水处治的主要方法是注浆封堵，浆液扩散机理、注浆量及注浆厚度确定、浆液与水相互作用以及新型注浆材料研发等方面值得进一步研究。所得研究结论与展望对于隧道及地下工程渗漏水防治的实践和研究具有积极意义。     

发动机气门导管座圈自动上料检测设计

提出了一种气门座圈导管自动上料检测机构,通过对导管座圈外形特征,提出了一种精确的检测手段,参与设计加工该检测机构,且通过实例实施,验证了该设计的可行性,工作效率高,操作安全,成本低,自动化程度高,为该机构的进一步研究及应用提供了理论依据。     

受电弓动态包络线检测

介绍国内外防止机车受电弓与接触网之间弓网故障的思路、方法 ,介绍受电弓动态包络线检测尺对接触悬挂进行动态包络线检测的应用情况。     

Fault detection of vehicle suspension system using wavelet analysis

This paper presents a method based on continuous wavelet transform to detect the faults of vehicle suspension systems. The Morlet wavelet functions are employed to approach the natural frequencies of the system and the frequency components of the signal with relative maximum energy. To evaluate our method, we use a full vehicle dynamic model which has been simulated in ADAMS/CAR and validated by laboratory test results. The suspension faults have been considered due to the damage of shock absorbers (dampers) and upper damper bushings (UDBs) and assumed as the decrease in damping force and loose joints, respectively. In this paper, the incapability of the spectral analysis by using fast Fourier transform in analysis of the signals is revealed through applying the inputs that include transient characteristics and then wavelet transform employed to achieve more proper results. A swept frequency is applied as an input to the wheels that simulates the road irregularities. After detection of faulty sections of the system using signal energy distribution, the defects of damper and UDBs are distinguished from each other through observing the changes of natural frequencies and corresponding energy amplitudes.     

Application of observer-based fault detection in vehicle roll control

This paper describes how observer-based techniques for intelligent fault detection were applied to monitoring an active suspension control system in an experimental articulated heavy vehicle. The aim was to define a practical method for detecting faults, taking into account the nonlinearities of the vehicle. The experimental vehicle was divided conceptually into subsystems, namely the passive dynamics of the trailer, the dynamics of the hydraulic actuators, and the expected response of the closed-loop system. A linear dynamic model was designed for each subsystem. A fault detection observer was then designed for each dynamic model. The observer feedback gains were chosen to optimise estimation by the observer residual of specified errors on the output measurements. The observer residuals were then normalised and combined logically to provide a fault diagnosis. The performance of the fault detection scheme is demonstrated in the case of sensor faults and changes in the operation of the active control system.     

钢架拱桥的检测与评估

随着我国公路建设规模不断增加,大跨径和钢结构桥梁的大量使用,在摸索和不断创新中桥梁理论和施工工艺新技术、新方法不断被推广使用。大跨径桥梁受益于钢结构的较大刚度,因此也被广泛应用于现代桥梁中。桥梁技术的不断进步要求桥梁检测技术也需要根据桥梁特点进行不断创新,检测和评估技术的好坏直接关系到桥梁的使用寿命和桥梁的使用安全性。对日常常用钢结构进行分析,以实际检测为例,通过对实际应用中的常规钢结构桥梁病害检测分析来说明检测评估的基本方法,根据检测相应结果对桥梁进行评估。     

空间聚集法在沥青路面裂缝自动检测中的应用

沥青路面施工质量与效果直接决定了道路的使用安全与寿命。然而,受到各类因素的影响其路面裂缝不可避免,在裂缝的影响下地表径流以及承载应力会形成对路基的冲刷与损害,进一步提升了道路病害出现的可能。在此基础上,通过构建空间聚集法的方式对沥青路面裂缝进行检测与评价不仅能够有效地收集所需信息,还能够在自动化与函数化的基础上提供更为准确的评价结果。