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Article
Publication date: 1 February 1985

P. Eisler

This is the final part of an abridged version of the previously unpublished writings of Paul Eisler, universally acknowledged as the inventor of the printed circuit board…

Abstract

This is the final part of an abridged version of the previously unpublished writings of Paul Eisler, universally acknowledged as the inventor of the printed circuit board and many other technical innovations. The content of the extracts presented has concentrated mainly on Dr Eisler's efforts in the field of printed circuit technology, followed by a few details of some of his other areas of invention.

Details

Circuit World, vol. 11 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 2 March 2015

M.K. Loganathan and O.P. Gandhi

Reliability assessment does require an effective structural modelling approach for systems, in general and manufacturing systems are no exception. This paper aims to…

Abstract

Purpose

Reliability assessment does require an effective structural modelling approach for systems, in general and manufacturing systems are no exception. This paper aims to develop it for large manufacturing systems using graph models, a systems approach.

Design/methodology/approach

Structural graph models for reliability at various hierarchical levels are developed by considering a CNC cam shaft grinding machine. The system reliability expression is obtained by converting the reliability graphs into equivalent matrices, which helps to evaluate and analyse system.

Findings

Using the obtained reliability expressions at various hierarchical levels of the system, it is possible not only to evaluate its reliability from structure point of view but also to identify weak structural elements from reliability point of view.

Research limitations/implications

The approach can be extended to include the influence of other parameters, such as human, component and environment, etc., on the system reliability.

Practical implications

The approach helps to design and develop manufacturing systems from reliability consideration by assessing their possible alternatives among these.

Originality/value

The suggested methodology is useful for reliability evaluation of large and complex manufacturing systems.

Details

Journal of Engineering, Design and Technology, vol. 13 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

Content available
Article
Publication date: 1 September 2006

Abstract

Details

Industrial Lubrication and Tribology, vol. 58 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 April 2006

S. Kanerva and A. Arkkio

To provide a general method for coupled simulation of electrical machines and circuits, using finite element analysis and a circuit/system simulator.

Abstract

Purpose

To provide a general method for coupled simulation of electrical machines and circuits, using finite element analysis and a circuit/system simulator.

Design/methodology/approach

The electrical machine is modelled by dynamic inductance and electromotive force (EMF), which are determined by finite element analysis and updated in time‐stepping procedure. Calculation of these parameters is based on current perturbations that are applied on linearized field equations after determining the operating point by nonlinear analysis.

Findings

Based on the case studies, the presented method can be utilized in coupled field‐circuit simulation and the results correlate with those obtained by other known methods. The results were also validated according to experimental data.

Research limitations/implications

Calculation of the EMF and the presented implementation for SIMULINK have some limitations regarding the accuracy and stability of the numerical integration. In the future, the numerical methods could be still improved and the implementations could be extended to other simulators.

Practical implications

Since the presented methodology is of a general type, the research provides means to include field‐circuit coupling into a variety of different simulation software.

Originality/value

Definitions of the circuit parameters differ from the conventional ones, as a result of which the parameter extraction can be performed in computation‐effective way. The benefits of the research are met widely, since the general‐purpose methodology is not limited to any single software.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 25 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 April 2014

Josef Šandera and Michal Nicák

This article aims to discuss the construction of a system for temperature cycling, where Peltier elements are used as heating or cooling elements. This article describes…

Abstract

Purpose

This article aims to discuss the construction of a system for temperature cycling, where Peltier elements are used as heating or cooling elements. This article describes the results and experiences based on several years of practice in the area of thermo-mechanical reliability of soldered joints on printed boards with SMD components.

Design/methodology/approach

The authors discuss the characteristics of the design, the threshold temperatures, dynamic properties of the system and, most importantly, the reliability and the useful life of the Peltier elements. The advantages and disadvantages of the system are mentioned as well as examples of use.

Findings

The utilisation of Peltier elements for temperature cycling is possible, but it is important to keep in mind that the reliability of the elements is similar to the reliability of the system, and therefore, it is essential to replace the defective Peltier elements during the cycling.

Research limitations/implications

The construction of system is very simply. It is necessary to ensure the Peltier elements with low dispersion parameters.

Originality/value

The system is very well suited for cycling of printed boards, especially one sided, multi-chip systems, COB systems, flip-chip embedded construction, etc. The system can be used in situations where it is possible to ensure an effective heat transfer and where extremely low temperatures are not required.

Details

Soldering & Surface Mount Technology, vol. 26 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 August 2016

Anthony Samano, Yanmeng Xu, David Harrison, Chris Hunt, Martin Wickham and Owen Thomas

The resistivity of cured conductive ink films are dependent on a wide range of process parameters. An early indication of the resistivity that is likely to result…

Abstract

Purpose

The resistivity of cured conductive ink films are dependent on a wide range of process parameters. An early indication of the resistivity that is likely to result following curing can enable these parameters to be optimised and, therefore, improve product quality. This paper aims to report on the use of alternating current (AC) impedance measurement techniques on curing printed ink films as a means of assessing the resistivity likely to be attained following the curing process.

Design/methodology/approach

Impedance measurements (100 Hz-10 MHz) were performed on curing conductive carbon ink films printed on polyethylene terephthalate substrates during convective heat curing. A jig was designed to incorporate the test structure in an convection oven such that the effect of cure on the structure impedance could be investigated.

Findings

The initial impedance was found to decrease with an increase in the measurement frequency. As the ink films were cured, the impedance magnitude across the 100 Hz-10 MHz range converged with the direct current (DC) resistance value. For a given ink, the ratio of initial AC impedance at 10 MHz to final cured resistance was found to be consistent, thus giving a method where final conductivity can be estimated before cure.

Originality/value

Data from printed ink resistance measurements are required to ensure the optimal conductivity of printed devices. However, after the printed structures are fabricated and cured, it is too late to optimise process parameters, leading to significant wastage. AC impedance measurement can give an indication of the final cured resistivity whilst the structure is freshly printed and still in its curing phase, enabling the printing process parameters to be adjusted to improve the resistivity of subsequently printed devices. Measuring AC impedance of printed ink structures in a production environment can, therefore, improve output.

Details

Circuit World, vol. 42 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Content available
Article
Publication date: 8 December 2020

Huiru Zhang, Limin Jia, Li Wang and Yong Qin

Based on complex network theory, a method for critical elements identification of China Railway High-speed 2 (CRH2) train system is introduced in this paper.

Abstract

Purpose

Based on complex network theory, a method for critical elements identification of China Railway High-speed 2 (CRH2) train system is introduced in this paper.

Design/methodology/approach

First, two methods, reliability theory and complex theory, are introduced, and the advantages and disadvantages for their application in identifying critical elements of high-speed train system are summarized. Second, a multi-layer multi-granularity network model including virtual and actual nodes is proposed, and the corresponding fusion rules for the same nodes in different layers are given.

Findings

Finally, taking CRH2 train system as an example, the critical elements are identified by using complex network theory, which provides a reference for train operation and maintenance.

Originality/value

A method of identifying key elements of CRH2 train system based on integrated importance indices is introduced, which is a meaningful extension of the application of complex network theory to identify key components.

Details

Smart and Resilient Transport, vol. 2 no. 1
Type: Research Article
ISSN: 2632-0487

Keywords

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Article
Publication date: 26 August 2020

Fatima Souad Bezzaoucha, M’hammed Sahnoun and Sidi Mohamed Benslimane

Improving reliability is a key factor in reducing the cost of wind energy, which is strongly influenced by the cost of maintenance operations. In this context, this paper…

Abstract

Purpose

Improving reliability is a key factor in reducing the cost of wind energy, which is strongly influenced by the cost of maintenance operations. In this context, this paper aims to propose a degradation model that describes the phenomenon of fault propagation to apply proactive maintenance that will act on the cause of failure to prevent its reoccurrence as well as to improve future system designs.

Design/methodology/approach

The methodology adopted consists in identifying the different components of a wind turbine, their causes and failure modes, and then, classifying these components according to their causes of failure.

Findings

The result is a classification of the different components of a wind turbine according to their failure causes. From the obtained classification, the authors observed that the failure modes for one component are a failure cause for another component, which describes the phenomenon of failure propagation.

Originality/value

The different classifications existing in the literature depend on the nature, position and function of the different components. The classification of this study consists in grouping the components of a wind turbine according to their failure causes to develop a degradation model considering the propagation of failure in the field of wind turbines.

Details

International Journal of Energy Sector Management, vol. 15 no. 2
Type: Research Article
ISSN: 1750-6220

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Article
Publication date: 11 January 2019

Fateme Dinmohammadi

Railway transport maintenance plays an important role in delivering safe, reliable and competitive transport services. An appropriate maintenance strategy not only reduces…

Abstract

Purpose

Railway transport maintenance plays an important role in delivering safe, reliable and competitive transport services. An appropriate maintenance strategy not only reduces the assets’ lifecycle cost, but also will ensure high standards of safety and comfort for rail passengers and workers. In recent years, the majority of studies have been focused on the application of risk-based tools and techniques to maintenance decision making of railway infrastructure assets (such as tracks, bridges, etc.). The purpose of this paper is to present a risk-based modeling approach for the inspection and maintenance optimization of railway rolling stock components.

Design/methodology/approach

All the “potential failure modes and root causes” related to rolling stock systems are identified from an extensive literature review followed by an expert’s panel assessment. The failure causes are categorized into six groups of electrical faults, structural damages, functional failures, degradation, human errors and natural (external) hazards. Stochastic models are then proposed to estimate the likelihood (probability) of occurrence of a failure in the rolling stock system. The consequences of failures are also modeled by an “inflated cost function” that involves safety-related costs, corrective maintenance and renewal (M&R) costs, the penalty charges due to train delays or service interruptions as well as the costs associated with loss of reputation (or loss of fares) in the case of trip cancellation. Lastly, a time-varying risk-cost function is formulated to determine the optimal frequency of preventive inspection and maintenance actions for rolling stock components.

Findings

For the purpose of clearly illustrating the proposed risk-based inspection and maintenance modeling methodology, a case study of the Class 380 train’s pantograph system from a Scottish train operating company is provided. The results indicate that the proposed model has a substantial potential to reduce the M&R costs while ensuring a higher level of safety and service quality compared to the currently used inspection methodologies.

Practical implications

The railway rolling stocks should be regularly inspected and maintained so as to ensure network availability and reliability, passenger safety and comfort, and operations efficiency. Despite the best efforts of the maintenance staff, it is reported that a considerable amount of maintenance resources (e.g. budget, time, manpower) is wasted due to insufficiency or inefficiency of current periodic M&R interventions. The model presented in this paper helps the maintenance engineers to assess the current maintenance practices and propose or initiate improvement actions when needed.

Originality/value

There are few studies investigating the application of risk-based tools and techniques to inspection and maintenance decision making of railway rolling stock components. This paper presents a modeling approach aimed at planning the preventive repair and maintenance interventions for rolling stock components based on risk measures. The author’s model is also capable of incorporating real measurement information gathered at each inspection epoch to update future inspection plans.

Details

Journal of Quality in Maintenance Engineering, vol. 25 no. 2
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 1 March 1992

H. Kober

Several important factors are often neglected or forgotten by engineers and designers with respect to designing for cost‐effective manufacture of the different types of…

Abstract

Several important factors are often neglected or forgotten by engineers and designers with respect to designing for cost‐effective manufacture of the different types of flexible printed circuits (FPCs). This paper discusses the various design features which influence the cost of FPC production, offers layout guidelines and considers the items affecting flexibility. Designing manufacturable products can lead to benefits such as reduced lead times, lower material costs, higher quality and increased yields.

Details

Circuit World, vol. 18 no. 4
Type: Research Article
ISSN: 0305-6120

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