Combined heat treatment of metal materials

2016 ◽  
Vol 35 (4) ◽  
pp. 1450-1459 ◽  
Author(s):  
Václav Kotlan ◽  
Roman Hamar ◽  
David Pánek ◽  
Ivo Doležel
Keyword(s):  
Heat Treatment ◽  
Numerical Solution ◽  
Design Methodology ◽  
Measured Data ◽  
Temperature Gradients ◽  
Comsol Multiphysics ◽  
Content Type ◽  
Coupled Problem ◽  
Field Temperature ◽  
Metal Materials

Purpose – The purpose of this paper is to propose and analyze a combined heat treatment of metal materials, consisting in classic induction pre-heating and/or post-heating and full heating by laser beam. This technology is prospective for some kinds of surface hardening and welding because its application leads to lowering of temperature gradients at the heated spots, which substantially reduces local residual mechanical strains and stresses. Design/methodology/approach – The task was solved like the 3D hard-coupled problem for electromagnetic field, temperature field and field of displacements. It was solved numerically using the techniques based on the FEM. For solution was used commercial software COMSOL Multiphysics, some parts were solved using own scripts in the software Agros. Findings – In the paper are shown results of the numerical solution and experimental measured data. Due the work the authors found that the influence of the pre-heating and post-heating really leads to limit the temperature gradients and from other measurements is clear that also to improving of the welding. Originality/value – The paper presents fully 3D nonlinear and nonstationary mathematical model of hybrid laser welding, its numerical solution experimental verification.

Design of a brushless excitation system utilizing pot cores

2015 ◽  
Vol 34 (6) ◽  
pp. 1740-1757
Author(s):  
Julian Veitengruber ◽  
Frank Rinderknecht ◽  
Horst E. Friedrich
Keyword(s):  
Design Methodology ◽  
Measured Data ◽  
Prototype System ◽  
Transfer System ◽  
Excitation System ◽  
Inductive Power Transfer ◽  
Content Type ◽  
Slip Rings ◽  
Brushless Excitation ◽  
System Compensation

Purpose – The purpose of this paper is to devote the optimal substitution of slip rings through an inductive power transfer system for field winding supply of generators or motors with a wound rotor. By a rotational pot-core transformer approach, the rotor-side energizing of the excitation windings can be provided isolated and free of wear. Design/methodology/approach – For design purpose, an analytical model of the inductive link and the compensation network elements is shown. Based on a pot-core transformer approach, possible types of compensation networks regarding motor-specific constraints were carried out and compared among themselves by parameter studies. The analytical parts of the model were subsequently validated with measured data of an appropriate core and accompanying FEM calculations. On the basis of an experimental prototype system, the approach has been tested both stationary and transient. Findings – The publication exemplifies how a brushless excitation system for generators and motors can be inexpensively designed and implemented. Originality/value – This paper systematically presents a comprehensive analytical approach for brushless excitation systems as well as a prototypical system. Compensation network elements regarding motor-specific constraints were carried out and compared among themselves by parameter studies.

Influence of the cavities on the PCB mechanical properties

Circuit World ◽  
2015 ◽  
Vol 41 (2) ◽  
pp. 76-79
Author(s):  
Boleslav Psota ◽  
Alexandr Otáhal ◽  
Ivan Szendiuch
Keyword(s):  
Mechanical Properties ◽  
Resonant Frequency ◽  
Design Methodology ◽  
Printed Circuit Boards ◽  
Measured Data ◽  
Circuit Boards ◽  
Frequency Range ◽  
Content Type ◽  
Printed Circuit ◽  
Acceleration Amplitude

Purpose – The main aim of this paper is to investigate the influence of the cavity coverage on the printed circuit boards (PCB) to the resonant frequency, acceleration and displacement. Design/methodology/approach – Tests were realized on four PCBs with different cavity areas. Frequency range of tests was between 10 and 2,000 Hz with 0.3 g acceleration amplitude. In addition, more simulations were performed to check different setups of the boards. Findings – From the calculated and measured data, it is clear that with the larger cavity area the resonance frequency drops. In case a greater number of components placed in cavities are needed on board, it is appropriate to use multiple smaller cavities than the bigger ones. Originality/value – Results in this paper could be very useful for PCB manufacturers and designers during designing of the new PCBs with cavities for dipped components.

Lasers in manufacturing: a review of technologies and applications

2015 ◽  
Vol 35 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Robert Bogue
Keyword(s):  
Heat Treatment ◽  
Power Generation ◽  
Design Methodology ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Manufacturing Processes ◽  
Laser Peening ◽  
Automotive Electronics ◽  
Content Type ◽  
Laser Technologies

Purpose – This paper aims to provide details of the role that lasers play in manufacturing processes. Design/methodology/approach – Following an introduction, this paper first considers laser technologies used in welding, cutting and drilling. Techniques which add material or modify material’s properties, namely, pulsed laser deposition, laser cladding, heat treatment and laser peening are then discussed. A number of specific applications are cited and finally, brief conclusions are drawn. Findings – This paper shows that many laser-based processes are used to conduct a range of critical functions in the automotive, electronics, aerospace, power generation, medical and other industries. Originality/value – This paper illustrates the importance of lasers in a diversity of manufacturing processes.

About the change of flow factors during the run-in process of lubricated contacts

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Achill Holzer ◽  
Katharina Schmitz
Keyword(s):  
Shear Flow ◽  
Surface Structure ◽  
Design Methodology ◽  
Test Bench ◽  
Flat Surface ◽  
Measured Data ◽  
Content Type ◽  
Lubricated Contacts ◽  
Digital Microscope ◽  
Experimental Test Bench

Purpose This paper aims to increase the knowledge of the run-in process of lubricated contacts in hydraulical pumps. When performing EHL simulations of tribological contacts, the surface influence needs to be taken into account. This experimental measurement wants to investigate the amount of change of the flow factors in the first hour of run of tribological contacts. Design/methodology/approach An experimental test bench is used to run-in several samples. After several minutes of running, samples are removed and the surface structure is captured using a digital microscope. With the measured data, flow factors are calculated. Findings The findings were clear that flow factors are highly direction-dependent, especially shear flow factors in radial directions experience almost no change. Overall, influence of the surface structure of up to 30% compared to a flat surface can be registered. Originality/value This paper helps to choose application-oriented values for the simulation of tribological contacts.

Locally conservative projection methods: benchmarking and practical implementation

2013 ◽  
Vol 33 (1/2) ◽  
pp. 663-687 ◽  
Author(s):  
Antoine Alexandre Journeaux ◽  
Nicolas Nemitz ◽  
Olivier Moreau
Keyword(s):  
Design Methodology ◽  
Three Dimensional ◽  
Projection Methods ◽  
Theoretical Description ◽  
Practical Implementation ◽  
Content Type ◽  
Conservative Method ◽  
Orthogonal Method ◽  
Coupled Problem ◽  
Locally Conservative

Purpose – This article presents a locally conservative projection method which aims to preserve the integral of a function and one operator among grad, div, or curl. Design/methodology/approach – After a theoretical description of the projection methods, the locally conservative projection is analytically tested and compared with the orthogonal method. In the second part, the implementation of the methods is described, and improvements are proposed. An industrial application of the present work, consisting in a magneto-thermal coupled problem, is then presented. Findings – The implementation of the conservative method is simpler than the implementation of the orthogonal method while presenting similar behaviour in terms of accuracy and conservation. Originality/value – The locally conservative method is extended to curl-conform and div-conform elements. Furthermore, three-dimensional studies are proposed.

Heat transfer enhancement of circular and square LED geometry

2019 ◽  
Vol 29 (5) ◽  
pp. 1877-1898 ◽  
Author(s):  
Sana Ben Salah ◽  
Mohamed Bechir Ben Hamida
Keyword(s):  
Design Methodology ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Comsol Multiphysics ◽  
Transfer Enhancement ◽  
Content Type ◽  
Light Emitting ◽  
New Distribution ◽  
Good Agreement

Purpose The purpose of this paper is to compare the thermal effect between square and circular geometry of light emitting diode (LED) with respect of the same surface for the intent of reducing the junction temperature. Design/methodology/approach The heat equation is presented in a dimensionless form. To solve it numerically subject to the boundary conditions, the authors realized a three-dimensional code with Comsol Multiphysics. Findings The model is validated with previously published works. The authors found a good agreement. Originality/value New design of heat sink is improved for circular LED and a reduction of 18 per cent of the junction temperature is permitted. The authors study the influence of various parameters: number and length of fins and number and width of splits. New distribution of multichip LED in circular geometry permits to put 42 chips instead of 36 chips with respect of the same surface and pitch and with reduction of the junction temperature by 16 per cent.

scholarly journals Vulnerable adults in police custody

2019 ◽  
Vol 22 (1) ◽  
pp. 5-8
Author(s):  
Ian Cummins
Keyword(s):  
Design Methodology ◽  
Research Literature ◽  
Police Custody ◽  
England And Wales ◽  
Content Type ◽  
Increased Risk ◽  
Vulnerable Adults

Purpose The purpose of this paper is to discuss the recent National Appropriate Adult Network (NAAN) report on the role of the appropriate adult. Design/methodology/approach This paper is based on the NAAN report and a review of relevant policy and research literature. Findings There to Help 2 highlights that there are still significant gaps in the provision of appropriate adult schemes across England and Wales. These gaps potentially place vulnerable adults at increased risk. Originality/value This paper is a review of recent research.

Co-workers’ perceptions of and reactions to employee’s involuntary demotion

2019 ◽  
Vol 41 (4) ◽  
pp. 740-757 ◽  
Author(s):  
Sophie Hennekam ◽  
Subramaniam Ananthram ◽  
Steve McKenna
Keyword(s):  
Design Methodology ◽  
Emotional Responses ◽  
Emotional Reaction ◽  
Content Type ◽  
Informational Justice ◽  
Behavioural Responses ◽  
Behavioural Reaction ◽  
Three Stages ◽  
Depth Interviews ◽  
The Way

Purpose The purpose of this paper is to investigate how individuals perceive and react to the involuntary demotion of a co-worker in their organisation. Design/methodology/approach The authors draw on 46 semi-structured in-depth interviews (23 dyads) with co-workers of demoted individuals. Findings The findings suggest that an individual’s observation of the demotion of a co-worker has three stages: their perception of fairness, their emotional reaction and their behavioural reaction. The perception of fairness concerned issues of distributive, procedural, interpersonal and informational justice. The emotional responses identified were feelings of disappointment/disillusion, uncertainty, vulnerability and anger. Finally, the behavioural reactions triggered by their emotional responses included expressions of voice, loyalty, exit and adaptation. Originality/value Perceptions of (in)justice perpetrated on others stimulate emotional and behavioural responses, which impacts organisational functioning. Managers should therefore pay attention to the way a demotion is perceived, not only by those directly concerned, but also by co-workers as observers.

Consumer value creation through WhatsApp use

2019 ◽  
Vol 32 (4) ◽  
pp. 455-471
Author(s):  
Jorge Cruz-Cárdenas ◽  
Jorge Guadalupe-Lanas ◽  
Ekaterina Zabelina ◽  
Andrés Palacio-Fierro ◽  
Margarita Velín-Fárez ◽  
...  
Keyword(s):  
Latin American ◽  
Value Creation ◽  
Emotional Support ◽  
Design Methodology ◽  
Instant Messaging ◽  
Role Performance ◽  
Content Type ◽  
Consumer Value ◽  
Depth Interviews ◽  
Practical Implications

Purpose The purpose of this paper is to understand in-depth how consumers create value in their lives using WhatsApp, the leading mobile instant messaging (MIM) application. Design/methodology/approach The study adopts the perspective of customer-dominant logic (CDL) and uses a qualitative multimethod design involving 3 focus groups and 25 subsequent in-depth interviews. The research setting was Ecuador, a Latin American country. Findings Analysis and interpretation of the participants’ stories made it possible to identify and understand the creation of four types of value: maintaining and strengthening relationships; improving role performance; emotional support; and entertainment and fun. In addition, the present study proposes a conceptual model of consumer value creation as it applies to MIM. Practical implications Understanding the way consumers create value in their lives using MIM is important not only for organizations that offer MIM applications, but also for those companies that develop other applications for mobile phones or for those who wish to use MIM as an electronic word-of-mouth vehicle. Originality/value The current study is one of the first to address the topic of consumer behavior in the use of technologies from the perspective of CDL; this perspective enables an integrated qualitative vision of value creation in which the consumer is the protagonist.

scholarly journals Advantages and potential challenges of data management in e-maintenance

2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo
Keyword(s):  
Data Management ◽  
Design Methodology ◽  
Management Practices ◽  
Future Research ◽  
Conceptual Approach ◽  
Content Type ◽  
Different Types ◽  
Maintenance Systems ◽  
Industry Leader ◽  
Practical Implications

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.

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