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Article
Publication date: 17 October 2008

Haixia Li, He Lin, Yongli Li and Aiping Wu

In order to study granularity, this paper aims to discuss how to construct granules from the view of panweighted field of pansystem.

77

Abstract

Purpose

In order to study granularity, this paper aims to discuss how to construct granules from the view of panweighted field of pansystem.

Design/methodology/approach

By changing the panweights of panweighted field – subdivision of panweights, increase/decrease of panweights and reallocating panweights, to construct proper granules is the approach taken.

Findings

This paper provides a new method of studying granularity. If the weights of panweighted field are subdivided, then the granularity diminishes; if the panweights of panweighted field are increased, then the corresponding granularity diminished. Contrarily, the decrease of panweights of panweighted field results in the corresponding granularity increased; by reallocating panweights, use different method to construct different granules, such as compatible class, neighbor operator, compatible core, s‐s core and so on.

Research limitations/implications

How to reallocate panweights is the main limitation.

Practical implications

A very useful advice for studying granularity.

Originality/value

This paper combines the granularity with panweighted field of pansystem, and studies granularity from the view of panweighted field of pansystems.

Details

Kybernetes, vol. 37 no. 9/10
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 17 May 2024

Aun Haider

This paper aims to comprehensively explore techniques for reducing solution time in finite element analysis (FEA), addressing the critical need for expediting computations to…

46

Abstract

Purpose

This paper aims to comprehensively explore techniques for reducing solution time in finite element analysis (FEA), addressing the critical need for expediting computations to facilitate agile design exploration within project timelines.

Design/methodology/approach

Drawing from a wide array of literature sources, this paper synthesizes and analyzes various methodologies used to enhance the efficiency of FEA. Techniques are scrutinized in terms of their applicability, effectiveness and potential limitations.

Findings

The review signifies application of linear assumptions across multiple facets of analysis and delves into matrix order reduction strategies, geometry simplification, symmetry exploitation, submodeling and mesh attribute control. It reveals how these techniques can effectively reduce computational burdens while maintaining acceptable levels of accuracy.

Research limitations/implications

While this review provides a comprehensive overview of existing efficiency enhancement techniques in FEA, it acknowledges inherent limitations of any synthesis-based study. Future research should focus on refining these methodologies.

Practical implications

The insights provided in this paper offer practical guidance for structural engineers and researchers seeking to optimize FEA workflows. By implementing these techniques, practitioners can expedite solution times and enhance their ability to explore design alternatives efficiently ultimately leading to cost savings and more robust structures.

Originality/value

This review contributes to the existing literature by offering a comprehensive synthesis of efficiency enhancement techniques in FEA. By highlighting the originality and value of each discussed methodology, this paper provides a roadmap for future research and practical implementation in the field of structural engineering.

Details

Aircraft Engineering and Aerospace Technology, vol. 96 no. 5
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 5 June 2017

Xue-Jun Cui, Ying-Jun Zhang, Bao-Jie Dou, Xian-Guang Zeng and Xiu-Zhou Lin

This paper aims to investigate the effects of deposition time on the structure and anti-corrosion properties of a micro-arc oxidation (MAO)/Al coating on AZ31B Mg alloy.

257

Abstract

Purpose

This paper aims to investigate the effects of deposition time on the structure and anti-corrosion properties of a micro-arc oxidation (MAO)/Al coating on AZ31B Mg alloy.

Design/methodology/approach

The study describes the fabrication of the coating via a combined process of MAO with multi-arc ion plating. The structure, composition and corrosion resistance of the coatings were evaluated using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and electrochemical methods.

Findings

The Al-layer is tightly deposited with a good mechanical interlock along the rough interface due to the Al diffusion. However, the Al layer reduces the anti-corrosion of MAO-coated Mg alloy because of structural defects such as droplets and cavities, which act as channels for corrosive media infiltration towards the substrate. Fortunately, the Al layer improves the substrate corrosion resistance owing to its passive behaviour, and the corrosion resistance can be enhanced with increasing deposition time. All results indicate that a buffer layer fabricated through the duplex process improves the interfacial compatibility between the hard coating and soft Mg alloys.

Originality/value

An MAO/Al duplex coating was fabricated via a combined process of MAO and physical vapour deposition. MAO/Al duplex coatings exhibit obviously passive behaviours on AZ31 Mg alloy. The structure and corrosion resistance of MAO/Al coatings were investigated.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 14 November 2019

Aiping Jiang, Qingxia Li, Jinyi Yan, Leqing Huang and Haining Wu

The purpose of this paper is to focus on finding the optimal maintenance interval and the minimum maintenance cost for redundant system, considering environment factors.

224

Abstract

Purpose

The purpose of this paper is to focus on finding the optimal maintenance interval and the minimum maintenance cost for redundant system, considering environment factors.

Design/methodology/approach

The authors propose a decision model with environment-based preventive maintenance for the repairable redundant system. Referring to the k-out-of-n model and Proportional Hazard Model, the reliability analysis is completed for the redundant system affected by internal and external issues. Meanwhile, the maintenance cost for the redundant system is divided into two categories: the fixed maintenance cost involving whole system replacement at the time of system failure, and the cost to replace failure components when the system still functions.

Findings

Upon the required reliability analysis, an optimal maintenance interval that minimizes the average maintenance cost per unit time is identified. The simulation results indicate that the optimal maintenance interval with consideration of environmental factors is significantly shorter than that without consideration of these factors, with the maintenance cost increase within 10 percent.

Practical implications

The redundant systems have widely been used in industries including the aero craft control system and warship power system. The model could be applied in the more real case considering the types of components and the operation environment, and help production managers better maintain machines by increasing the safety and reliability of the redundant model with the more frequent inspection.

Originality/value

Previous research of redundant system always focuses on internal degradation, while ignoring the reliability analysis for a redundant system with various multiple components under the influence of environment. However, this work could fill the theoretical gap, i.e. simultaneously consider both environmental and internal factors for a redundant system with non-homogeneous components. Meanwhile, the proposed superior model increases the reliability and safety of the k-out-of-n model with reasonable cost. Production managers could benefit a lot from this as well.

Details

Journal of Quality in Maintenance Engineering, vol. 26 no. 4
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 10 September 2019

Zhenpeng Wu, Vanliem Nguyen, Zhihong Zhang and Liangcai Zeng

The stepped topography of the friction pairs mainly causes the fluid film thickness to change in the direction of motion. In this region, there have very few topographical design…

85

Abstract

Purpose

The stepped topography of the friction pairs mainly causes the fluid film thickness to change in the direction of motion. In this region, there have very few topographical design methods for continuous or non-linear distribution of the fluid film. The purpose of this study is to analyze the effect of the curved surface on the performance of the liquid film.

Design/methodology/approach

First, a numerical simulation is used to solve the optimal bearing capacity and friction coefficient of the liquid film under the condition of the minimum film thickness. Then, the curved surface described by the sinusoidal curve equation is applied in the transitional region of maximum and minimum film thickness. The bearing capacity and the friction coefficient of the liquid film are respectively simulated and compared in the same condition of the minimum film thickness.

Findings

The research results show that the liquid film using the curved surface transition model, the optimal bearing capacity is significantly increased by 32 per cent while the optimal friction coefficient is clearly reduced by 38 per cent in comparison with using stepped surface model.

Originality/value

The friction pair with curved transition enables better lubrication performance of the liquid film and better adaptability under unstable conditions.

Details

Industrial Lubrication and Tribology, vol. 72 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 9 April 2019

Zhenpeng Wu, Xianzhong Ding, Liangcai Zeng, Xiaolan Chen and Kuisheng Chen

This paper aims to use the method of curve splicing to combine the slip zone and the no-slip zone to further improve the lubrication performance of the liquid film. The…

199

Abstract

Purpose

This paper aims to use the method of curve splicing to combine the slip zone and the no-slip zone to further improve the lubrication performance of the liquid film. The combination of the slip zone and the no-slip zone of an existing heterogeneous surface is still a single line stitching method so that a very large residual space at the surface of the friction pairs remains present, necessitating further improvement of the joining scheme between the slip zone and the no-slip zone in heterogeneous surfaces.

Design/methodology/approach

A set of discrete sinusoids is used as the splicing track for both the slip zone and the no-slip zone, the starting point and amplitude of the curve are introduced as the simulation variables and the effects of these variables on the bearing capacity and friction coefficient of the liquid film are comprehensively analyzed.

Findings

The results show that the method of selecting the sinusoidal curve as the slip zone and the no-slip zone trajectory, which is based on the existing method of linear stitching, can further enhance the bearing capacity and reduce the friction coefficient of the liquid film.

Originality/value

This method can further enhance the bearing capacity and reduce the friction coefficient of the liquid film.

Details

Industrial Lubrication and Tribology, vol. 71 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 3 September 2020

Weiwei Wu, Zhouzhou Wang, Shuang Ding, Aiping Song and Dejia Zhu

The effects of infiltrant-related factors during post-processing on mechanical performance are fully considered for three-dimensional printing (3DP) technology. The factors…

112

Abstract

Purpose

The effects of infiltrant-related factors during post-processing on mechanical performance are fully considered for three-dimensional printing (3DP) technology. The factors contain infiltrant type, infiltrating means, infiltrating frequency and time interval of infiltrating.

Design/methodology/approach

A series of printing experiments are conducted and the parts are processed with different conditions by considering the above mentioned four parameters. Then the mechanical performances of the parts are tested from both macroscopic and microscopic papers. In the macroscopic view, the compressive strength of each printed part is measured by the materials testing machine – Instron 3367. In the microscopic view, scanning electron microscope and energy dispersion spectrum are used to obtain microstructure images and element content results. The pore size distributions of the parts are measured further to illustrate that if the particles are bound tightly by infiltrant. Then, partial least square (PLS) is used to conduct the analysis of the influencing factors, which can solve the small-sample problem well. The regression analysis and the influencing degree of each factor are explored further.

Findings

The experimental results show that commercial infiltrant has an outstanding performance than other super glues. The infiltrating action will own higher compressive strength than the brushing action. The higher infiltrating frequency and inconsistent infiltrating time interval will contribute to better mechanical performance. The PLS analysis shows that the most important factor is the infiltrating method. When compare the fitted value with the actual value, it is clear that when the compressive strength is higher, the fitting error will be smaller.

Practical implications

The research will have extensive applicability and practical significance for powder-based additive manufacturing.

Originality/value

The impact of the infiltrating-related post-processing on the performance of 3DP technology is easy to be ignored, which is fully taken into consideration in this paper. Both macroscopic and microscopic methods are conducted to explore, which can better explain the mechanical performance of the parts. Furthermore, as a small-sample method, PLS is used for influencing factors analysis. The variable importance in the projection index can explain the influencing degree of each parameter.

Details

Rapid Prototyping Journal, vol. 26 no. 9
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 9 August 2024

Juanyan Miao, Yiwen Li, Siyu Zhang, Honglei Zhao, Wenfeng Zou, Chenhe Chang and Yunlong Chang

The purpose of this study is to optimize and improve conventional welding using EMF assisted technology. Current industrial production has put forward higher requirements for…

70

Abstract

Purpose

The purpose of this study is to optimize and improve conventional welding using EMF assisted technology. Current industrial production has put forward higher requirements for welding technology, so the optimization and improvement of traditional welding methods become urgent needs.

Design/methodology/approach

External magnetic field assisted welding is an emerging technology in recent years, acting in a non-contact manner on the welding. The action of electromagnetic forces on the arc plasma leads to significant changes in the arc behavior, which affects the droplet transfer and molten pool formation and ultimately improve the weld seam formation and joint quality.

Findings

In this paper, different types of external magnetic fields are analyzed and summarized, which mainly include external transverse magnetic field, external longitudinal magnetic field and external cusp magnetic field. The research progress of welding behavior under the effect of external magnetic field is described, including the effect of external magnetic field on arc morphology, droplet transfer and weld seam formation law.

Originality/value

However, due to the extremely complex physical processes under the action of the external magnetic field, the mechanism of physical fields such as heat, force and electromagnetism in the welding has not been thoroughly analyzed, in-depth theoretical and numerical studies become urgent.

Details

Rapid Prototyping Journal, vol. 30 no. 9
Type: Research Article
ISSN: 1355-2546

Keywords

Available. Open Access. Open Access
Book part
Publication date: 1 May 2019

Raido Puust, Irene Lill and Roode Liias

This study aims to initiate an investigation into the drop-out rate from building information modelling (BIM) courses.

Abstract

Purpose

This study aims to initiate an investigation into the drop-out rate from building information modelling (BIM) courses.

Design/Methodology/Approach

During 2017-2018, BIM courses (16 weeks) have been developed as active learning modules. Peer instruction was used to engage students and improve the overall student’s performance. Students’ activity data were captured and analysed based on study groups and suggested study module completion dates.

Findings

By mapping students’ activity data against suggested completion date at various assessment milestones revealed a possible degradation of motivation throughout the course which, in turn, may have been a possible cause of drop-out.

Research Limitations/Implications

This paper presents ongoing research and a preliminary understanding about peer instruction effectiveness in BIM-related subjects as high intensity courses. It investigates whether a student’s active participation can improve their motivation to acquire a subject’s learning outcomes and reduce the drop-out.

Practical Implications

The peer instruction methodology that is used here is quite universal and can be successfully applied to various other subjects to increase the student’s involvement in the course.

Originality/Value

Results are drawn based on students’ involvement at the high intensity course and show the gradual increase of a learner’s motivation once they get continuous support from fellow learners and a teacher.

Details

10th Nordic Conference on Construction Economics and Organization
Type: Book
ISBN: 978-1-83867-051-1

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Article
Publication date: 5 March 2018

Katerina Gotzamani, Andreas Georgiou, Andreas Andronikidis and Konstantina Kamvysi

The purpose of this paper is to provide an enhanced version of quality function deployment (QFD) that captures customers’ present and future preferences, accurately prioritizes…

618

Abstract

Purpose

The purpose of this paper is to provide an enhanced version of quality function deployment (QFD) that captures customers’ present and future preferences, accurately prioritizes product specifications and eventually translates them into desirable quality products. Under rapidly changing environments, customer requirements and preferences are constantly changing and evolving, rendering essential the realization of the dynamic role of the “Voice of the Customer (VoC)” in the design and development of products.

Design/methodology/approach

The proposed methodological framework incorporates a Multivariate Markov Chain (MMC) model to describe the pattern of changes in customer preferences over time, the Fuzzy AHP method to accommodate the uncertainty and subjectivity of the “VoC” and the LP-GW-AHP to discover the most important product specifications in order to structure a robust QFD method. This enhanced QFD framework (MMC-QFD-LP-GW-Fuzzy AHP) takes into consideration the dynamic nature of the “VoC” captures the actual customers’ preferences (WHATs) and interprets them into design decisions (HOWs).

Findings

The integration of MMC models into the QFD helps to handle the sequences of customers’ preferences as categorical data sequences and to consider the multiple interdependencies among them.

Originality/value

In this study, a MMC model is introduced for the first time within QFD, in an effort to extend the concept of listening to further anticipating to customer wants. Gaining a deeper understanding of current and future customers’ preferences could help organizations to design products and plan strategies that more effectively and efficiently satisfy them.

Details

International Journal of Quality & Reliability Management, vol. 35 no. 3
Type: Research Article
ISSN: 0265-671X

Keywords

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