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1 – 10 of over 5000
Article
Publication date: 15 September 2023

Deepak Kumar Prajapati, Jitendra Kumar Katiyar and Chander Prakash

This study aims to use a machine learning (ML) model for the prediction of traction coefficient and asperity load ratio for different surface topographies of non-conformal rough…

Abstract

Purpose

This study aims to use a machine learning (ML) model for the prediction of traction coefficient and asperity load ratio for different surface topographies of non-conformal rough contacts.

Design/methodology/approach

The input data set for the ML model is generated using a mixed-lubrication model. Surface topography parameters (skewness, kurtosis and pattern ratio), rolling speed and hardness are used as input features in the multi-layer perceptron (MLP) model. The hyperparameter tuning and fivefold cross-validation are also performed to minimize the overfitting.

Findings

From the results, it is shown that the MLP model shows excellent accuracy (R2 > 90%) on the test data set for making the prediction of mixed lubrication parameters. It is also observed that engineered rough surfaces with high negative skewness, low kurtosis and isotropic surface patterns exhibit a significant low traction coefficient. It is also concluded that the MLP model gives better accuracy in comparison to the random forest regression model based on the training and testing data sets.

Originality/value

Mixed lubrication parameters are predicted by developing a regression-based MLP model. The machine learning model is trained using several topography parameters, which are vital in the mixed-EHL regime because of the lack of regression-fit expressions in previous works. The accuracy of MLP with random forest models is also compared.

Details

Industrial Lubrication and Tribology, vol. 75 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 31 August 2023

Shaoxuan Li, Yi Xu, Haiqing Xia, Jing Duan, Yingjie Yu, Xingyun Duan, Pengfei Shi and Jiancheng Tang

Tantalum is a kind of metal material with moderate hardness, high ductility, small thermal expansion coefficient, excellent corrosion resistance and outstanding biocompatibility…

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Abstract

Purpose

Tantalum is a kind of metal material with moderate hardness, high ductility, small thermal expansion coefficient, excellent corrosion resistance and outstanding biocompatibility. The purpose of this study is that its tribological performance could be tested and analyzed so as to use it in different fields.

Design/methodology/approach

The friction resistance of a-Ta under dry friction conditions was tested at different roads. The relationships between load and friction coefficient, wear rate and two-dimensional shape of wear scars were studied.

Findings

The stable Ta2O5 film with lubrication effect was generated in the process of friction. And, the larger the test load, the more Ta2O5 would be generated.

Originality/value

This work lays a theoretical foundation for tantalum as an excellent wear-resistant material.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2023-0047/

Details

Industrial Lubrication and Tribology, vol. 75 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 8 September 2023

Xintian Liu and Muzhou Ma

Scholars mainly propose and establish theoretical models of cumulative fatigue damage for their research fields. This review aims to select the applicable model from many fatigue…

Abstract

Purpose

Scholars mainly propose and establish theoretical models of cumulative fatigue damage for their research fields. This review aims to select the applicable model from many fatigue damage models according to the actual situation. However, relatively few models can be generally accepted and widely used.

Design/methodology/approach

This review introduces the development of cumulative damage theory. Then, several typical models are selected from linear and nonlinear cumulative damage models to perform data analyses and obtain the fatigue life for the metal.

Findings

Considering the energy law and strength degradation, the nonlinear fatigue cumulative damage model can better reflect the fatigue damage under constant and multi-stage variable amplitude loading. In the following research, the complex uncertainty of the model in the fatigue damage process can be considered, as well as the combination of advanced machine learning techniques to reduce the prediction error.

Originality/value

This review compares the advantages and disadvantages of various mainstream cumulative damage research methods. It provides a reference for further research into the theories of cumulative fatigue damage.

Details

International Journal of Structural Integrity, vol. 14 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 17 April 2024

Jian Sun, Zhanshuai Fan, Yi Yang, Chengzhi Li, Nan Tu, Jian Chen and Hailin Lu

Aluminum alloy is considered an ideal material in aerospace, automobile and other fields because of its lightweight, high specific strength and easy processing. However, low…

Abstract

Purpose

Aluminum alloy is considered an ideal material in aerospace, automobile and other fields because of its lightweight, high specific strength and easy processing. However, low hardness and strength of the surface of aluminum alloys are the main factors that limit their applications. The purpose of this study is to obtain a composite coating with high hardness and lubricating properties by applying GO–PVA over MAO coating.

Design/methodology/approach

A pulsed bipolar power supply was used as power supply to prepare the micro-arc oxidation (MAO) coating on 6061 aluminum sample. Then a graphene oxide-polyvinyl alcohol (GO–PVA) composite coating was prepared on MAO coating for subsequent experiments. Samples were characterized by Fourier infrared spectroscopy, X-ray diffraction, Raman spectroscopy and thermogravimetric analysis. The friction test is carried out by the relative movement of the copper ball and the aluminum disk on the friction tester.

Findings

Results showed that the friction coefficient of MAO samples was reduced by 80% after treated with GO–PVA composite film.

Originality/value

This research has made a certain contribution to the surface hardness and tribological issues involved in the lightweight design of aluminum alloys.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2023-0427/

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 30 October 2023

Hasan Valiyan and Mohammadreza Abdoli

The purpose of this study is to investigate the effect of anarchist accounting (AA) on stakeholder relationship capability (SRC) in the context of Iranian capital market companies.

Abstract

Purpose

The purpose of this study is to investigate the effect of anarchist accounting (AA) on stakeholder relationship capability (SRC) in the context of Iranian capital market companies.

Design/methodology/approach

This study is based on a descriptive survey-correlation data collection method. As this study is on (AA) and (SRC) in Iran, the population of the study is made up of all financial managers and heads of the accounting department of capital market companies in Iran. Among 185 companies (Tehran Stock Exchange [TSE]), 100 companies were selected as samples which are all in the TSE. As suggested by Niles (2006), a minimum sample size of 10% of the population is generally acceptable. A questionnaire survey was adopted in obtaining primary data for this study. Thus, based on Cochran sampling techniques, 395 questionnaires were returned and became the basis of analysis. Also, partial least square was used to test the research hypothesis.

Findings

The statistical findings indicate the fit of the structural desirability of the factor load and according to the standardized coefficient (path coefficient), the dimensions of AA have a negative and significant effect on SRC, because the path coefficient is positive.

Originality/value

Theoretically, to the best of the authors’ knowledge, this study is the first research that tries to examine the stakeholder relationship capability through the link between social/political approaches with accounting procedures, an issue that has not been considered in any prior study. Also, conducting the present study in the conditions of social distrust in the Iranian capital market can be important, because the expansion of anarchist accounting helps to create a level of symmetry and equality in information disclosure and it can create value for shareholders.

Details

Journal of Accounting & Organizational Change, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1832-5912

Keywords

Article
Publication date: 9 May 2023

Yuhai Shen, Yanshuang Wang, Jianghai Lin, Pu Zhang, Xudong Gao and Zijun Wang

This paper aims to determine a suitable anti-wear and friction-reducing compounding additive for lithium greases (LG) by investigating the effects of three single additives…

Abstract

Purpose

This paper aims to determine a suitable anti-wear and friction-reducing compounding additive for lithium greases (LG) by investigating the effects of three single additives potassium borate (PB), zinc dialkyl dithiophosphate and molybdenum dialkyl dithiophosphate (MoDDP) and two compound additives on the friction, wear and extreme pressure properties of LG.

Design/methodology/approach

The effects of the above five additives on the friction, wear and extreme pressure properties of LG were investigated using an SRV-5 friction tester. An X-ray photoelectron spectrometer was used to analyze the various elements presented on the wear surface as well as the types of compounds.

Findings

The compound additive suitable for grease consists of PB and MoDDP, which have excellent friction reduction, anti-wear and extreme pressure properties. And a boundary protection film consisting of oxide and MoS2 is formed on the friction surface, thus improving the friction reduction and anti-wear performance of the grease.

Originality/value

This study can improve the anti-wear and friction-reduction performance of greases, which is of great importance in the field of industrial lubrication. The results of this paper are expected to be useful to researchers and academics of grease.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2022-0350/

Details

Industrial Lubrication and Tribology, vol. 75 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 18 April 2023

Raphael Lissillour, Yuting Cui, Khaled Guesmi, Weijian Chen and Qianran Chen

This study aims to empirically examine the relationships among perceived environmental uncertainty (EV), the level of knowledge distance (KD) and the impact of value network on…

Abstract

Purpose

This study aims to empirically examine the relationships among perceived environmental uncertainty (EV), the level of knowledge distance (KD) and the impact of value network on firm performance.

Design/methodology/approach

The quantitative analysis is based on data from 243 Chinese companies with engineering, procurement and construction (EPC) business in the context of the COVID-19 pandemic.

Findings

The two dimensions of value network [network centrality (NC) and network openness (NO)] have a different impact on firm performance [financial performance (FP) and market performance (MP)]. NC has a positive impact on FP, but not on MP. NO has a positive effect on MP, but not on FP. A reduced KD mediates the relationship between value network and firm performance. Moreover, it fully mediates the relationship between NC and MP, NO and FP. Finally, during the COVID-19 pandemic, only EV has a moderating effect on KD and MP.

Research limitations/implications

This study is limited in terms of data set because it relies on a limited amount of cross-sectional data from one specific country. Therefore, researchers are encouraged to test the proposed propositions further.

Practical implications

The present findings suggest that EPC professionals should pay more attention to the EV, which may be impacted by policy, technology and the economy. This research has actionable implications for the reform of EPC in the construction industry, and practical recommendations for EPC firms to improve their corporate performance.

Originality/value

The results measure the complementary effects of both dimensions of value network (NC and NO) on two distinct aspects of firm performance (MP and FP) and assess the moderating effect of EV and KD in the context of the COVID-19 pandemics.

Details

Journal of Knowledge Management, vol. 28 no. 1
Type: Research Article
ISSN: 1367-3270

Keywords

Article
Publication date: 4 March 2024

Tri Dang Quan, Garry Wei-Han Tan, Eugene Cheng-Xi Aw, Tat-Huei Cham, Sriparna Basu and Keng-Boon Ooi

The main aim of this study is to examine the effect of virtual store atmospheric factors on impulsive purchasing in the metaverse context.

Abstract

Purpose

The main aim of this study is to examine the effect of virtual store atmospheric factors on impulsive purchasing in the metaverse context.

Design/methodology/approach

Grounded in purposive sampling, 451 individuals with previous metaverse experience were recruited to accomplish the objectives of this research. Next, to identify both linear and nonlinear relationships, the data were analyzed using partial least squares structural equation modeling (PLS-SEM) and artificial neural network (ANN) approaches.

Findings

The findings underscore the significance of the virtual store environment and online trust in shaping impulsive buying behaviors within the metaverse retailing setting. Theoretically, this study elucidates the impact of virtual store atmosphere and trust on impulsive buying within a metaverse retail setting.

Practical implications

From the findings of the study, because of the importance of virtual shop content, practitioners must address its role in impulse purchases via affective online trust. The study’s findings are likely to help retailers strategize and improve their virtual store presentations in the metaverse.

Originality/value

The discovery adds to the understanding of consumer behavior in the metaverse by probing the roles of virtual store atmosphere, online trust and impulsive buying.

Details

Asia Pacific Journal of Marketing and Logistics, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-5855

Keywords

Article
Publication date: 18 January 2024

Minglang Zhang, Xue Zuo and Yuankai Zhou

The purpose of this paper is to reveal the dynamic contact characteristics of the slip ring. Dynamic contact resistance models considering wear and self-excited were established…

Abstract

Purpose

The purpose of this paper is to reveal the dynamic contact characteristics of the slip ring. Dynamic contact resistance models considering wear and self-excited were established based on fractal theory.

Design/methodology/approach

The effects of tangential velocity, stiffness and damping coefficient on dynamic contact resistance are studied. The relationships between fractal parameters, wear time and contact parameters are revealed.

Findings

The results show that the total contact area decreases with the friction coefficient and fractal roughness under the same load. Self-excited vibration occurs at a low speed (less than 0.6 m/s). It transforms from stick-slip motion at 0.4 m/s to pure sliding at 0.5 m/s. A high stiffness makes contact resistance fluctuate violently, while increasing the damping coefficient can suppress the self-excited vibration and reduce the dynamic contact resistance. The fractal contact resistance model considering wear is established based on the fractal parameters models. The validity of the model is verified by the wear tests.

Originality/value

The results have a great significance to study the electrical contact behavior of conductive slip ring.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2023-0300/

Details

Industrial Lubrication and Tribology, vol. 76 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Open Access
Article
Publication date: 19 March 2024

Chun Tian, Gengwei Zhai, Mengling Wu, Jiajun Zhou and Yaojie Li

In response to the problem of insufficient traction/braking adhesion force caused by the existence of the third-body medium on the rail surface, this study aims to analyze the…

Abstract

Purpose

In response to the problem of insufficient traction/braking adhesion force caused by the existence of the third-body medium on the rail surface, this study aims to analyze the utilization of wheel-rail adhesion coefficient under different medium conditions and propose relevant measures for reasonable and optimized utilization of adhesion to ensure the traction/braking performance and operation safety of trains.

Design/methodology/approach

Based on the PLS-160 wheel-rail adhesion simulation test rig, the study investigates the variation patterns of maximum utilized adhesion characteristics on the rail surface under different conditions of small creepage and large slip. Through statistical analysis of multiple sets of experimental data, the statistical distribution patterns of maximum utilized adhesion on the rail surface are obtained, and a method for analyzing wheel-rail adhesion redundancy based on normal distribution is proposed. The study analyzes the utilization of traction/braking adhesion, as well as adhesion redundancy, for different medium under small creepage and large slip conditions. Based on these findings, relevant measures for the reasonable and optimized utilization of adhesion are derived.

Findings

When the third-body medium exists on the rail surface, the train should adopt the low-level service braking to avoid the braking skidding by extending the braking distance. Compared with the current adhesion control strategy of small creepage, adopting appropriate strategies to control the train’s adhesion coefficient near the second peak point of the adhesion coefficient-slip ratio curve in large slip can effectively improve the traction/braking adhesion redundancy and the upper limit of adhesion utilization, thereby ensuring the traction/braking performance and operation safety of the train.

Originality/value

Most existing studies focus on the wheel-rail adhesion coefficient values and variation patterns under different medium conditions, without considering whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train. Therefore, there is a risk of traction overspeeding/braking skidding. This study analyzes whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train and whether there is redundancy. Based on these findings, relevant measures for the reasonable and optimized utilization of adhesion are derived to further ensure operation safety of the train.

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