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Article
Publication date: 15 September 2021

Xiangyu Du, Junying Yang, Fei Gao, Xiaoming Han and Linlin Su

This paper aims to reveal the effects of the copper third body on different copper matrix friction materials with a novel experimental way called “exogenous powder.”

157

Abstract

Purpose

This paper aims to reveal the effects of the copper third body on different copper matrix friction materials with a novel experimental way called “exogenous powder.”

Design/methodology/approach

An accurate adding device of exogenous copper powder was designed to control the flow rate. The tribological properties with and without exogenous copper powder were investigated by a pin-on-disc tribometer during dry sliding.

Findings

Experimental results indicate that the Cu addition tends to increase the friction coefficient. For pure Cu material, the exogenous copper third body exhibits poor fluidity on the friction surface, causing serious adhesive wear on the friction interface. For the Cu 90% + 10% Gr material, the plasticity of exogenous copper powder may intensify the deformation of the third body of the surface, presenting layered accumulation distribution. For the pure Cu and Cu 95% + 5% SiO2 material, the Cu addition makes the composition and density of the third body uneven in the direction of depth.

Originality/value

The role of the copper component on different materials is revealed from a new perspective, and the relationship between the third body structure and the friction properties is explored.

Details

Industrial Lubrication and Tribology, vol. 73 no. 7
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 15 September 2020

Ziku Wu, Xiaoming Han and GuoFeng Li

The purpose of this paper is to develop a mesh-free algorithm based on the least square support vector machines method for numerical simulation of the modified Helmholtz equations.

72

Abstract

Purpose

The purpose of this paper is to develop a mesh-free algorithm based on the least square support vector machines method for numerical simulation of the modified Helmholtz equations.

Design/methodology/approach

The proposed method deals with a Cauchy problem for the modified Helmholtz equations. The algorithm converts the problem into a quadratic programming. It can be divided into three steps. First, some training points are allocated. Then, an approximate function is constructed. Finally, the shape parameters are estimated.

Findings

The proposed method's stability is discussed. Numerical experiments are conducted to check the efficiency of the algorithm. The proposed method is found to feasible for the ill-posed problems of the modified Helmholtz equations.

Originality/value

The originality lies in that the proposed method is applied to solve the modified Helmholtz equations for the first time, and the expected results are obtained.

Details

Engineering Computations, vol. 38 no. 2
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 30 January 2025

Xiaoming Han, He Zhang and Kangjian Yang

This study aims to investigate the temperature rise characteristics of vibrating rolling bearings under the influence of the polarization force of unbalanced eccentric blocks. A…

5

Abstract

Purpose

This study aims to investigate the temperature rise characteristics of vibrating rolling bearings under the influence of the polarization force of unbalanced eccentric blocks. A thermal-fluid-solid mechanics coupled finite element model is established to analyze the effects of different loads and rotational speeds on bearing temperature to prevent overheating, wear and thermal damage.

Design/methodology/approach

A thermal-fluid-solid mechanics coupled finite element model of the vibrating rolling bearing is developed based on the principles of heat transfer. Finite element analysis software is used to conduct numerical simulations and study the temperature distribution of the bearing system under different loads and speeds. The model’s accuracy is verified by experimentally measuring the actual temperature of the bearing under the same working conditions.

Findings

This study successfully established a thermal-fluid-solid mechanics coupled finite element model of a vibrating rolling bearing, verifying its accuracy and reliability. The research results provide an essential reference for optimizing bearing design, preventing overheating and extending service life.

Research limitations/implications

By analyzing the temperature rise characteristics under various load and rotational speed conditions, the law governing the internal temperature distribution of bearings is revealed. This finding offers a theoretical foundation for comprehending the thermal behavior of bearings.

Practical implications

This study offers a scientific foundation for the maintenance and fault diagnosis of shaker rolling bearings, aiding in the timely identification and resolution of thermal damage issues. Through the optimization of bearing design and usage conditions, the equipment’s lifespan can be prolonged, maintenance expenses can be minimized and production efficiency can be enhanced.

Originality/value

A thermal-fluid-solid mechanics coupled finite element model of a vibrating rolling bearing was established, considering the interaction of multiple physical fields. The influence of the polarization force from the unbalanced eccentric block on the bearing temperature is analyzed in detail, which is close to the actual working conditions.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2024-0396/

Details

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

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Article
Publication date: 16 December 2024

Chong Zhao, Manqi Yao, Xiaoming Han, Wei Qi, Linlin Su, Rong Fu and Fei Gao

This study aims to analyze the temperature difference between aluminum-based brake disc (ABD) and cast steel brake disc (CSBD) for rail vehicles in the braking process, which is…

9

Abstract

Purpose

This study aims to analyze the temperature difference between aluminum-based brake disc (ABD) and cast steel brake disc (CSBD) for rail vehicles in the braking process, which is related to the popularization and use of ABD.

Design/methodology/approach

Two friction pairs composed of ABD, CSBD and copper-based powder metallurgy brake pad were studied in this paper. The temperature characteristics of the two friction pairs were compared by 1:1 braking test and simulation calculation.

Findings

When the speed is 160–250 km/h and the braking pressure is 18 and 29 kN, the calculated maximum temperature of CSBD is 574°C and 681°C, respectively, which is higher than that of ABD 49°C–148°C and 73°C–217°C. Under the test conditions, the maximum temperature of CSBD is 487°C and 624°C respectively, which is higher than that of ABD 63°C–95°C and 63°C–188°C. The temperature difference between ABD and CSBD increases with the increase of braking pressure and speed. The surface temperature distribution of CSBD is “three-peak,” whereas that of ABD is “single-peak.”

Originality/value

This paper reveals the temperature difference between ABD and CSBD and provides data support for promoting the use of ABD.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2024-70320/

Details

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

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Article
Publication date: 22 August 2022

Youjie Chen, Fei Gao, Rong Fu, Linlin Su, Xiaoming Han and Junying Yang

This study aims to clarify the relationship of friction material type and brake disc temperature through braking experiment.

157

Abstract

Purpose

This study aims to clarify the relationship of friction material type and brake disc temperature through braking experiment.

Design/methodology/approach

The braking performances of resin materials (RM), semimetallic materials (SM) and copper-based powder metallurgy materials (PM) friction blocks mating with forged steel brake disc were examined based on TM-I-type reduced-scale inertial braking dynamometer. The brake disc surface temperature was recorded by infrared thermal camera during braking.

Findings

Experimental results indicate that the thermal wear resistance of three friction materials differs with mental content, resulting in the deviation of pad-disc system contact state during braking, thus forming different temperature distribution on the brake disc surface. The peak temperature on the disc face of RM (190°C) is 36.6% and 45.4% lower than that of PM (300°C) and SM (348°C) at 160 km/h. The maximum radial temperature deviation of PM (35°C) is approximately three times than that of RM (12°C) and 40% higher than that of SM (25°C) at 50 km/h, whereas the maximum temperature deviation of SM (97°C) is six times than that of RM (16°C) and 31% higher than that of PM (74°C) at 160 km/h.

Originality/value

The effect of friction material type on the disc surface temperature distribution is revealed, which provides a meaningful reference for the design of brake friction pairs and choice of brake pad materials.

Details

Industrial Lubrication and Tribology, vol. 74 no. 8
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 14 March 2016

Fei Gao, Jia Miao, Xiaoming Han, Rong Fu and Jiguang Chen

Since the multi-component of powder metallurgy was dispersed, and each component sheared flow and tiered under the action of friction force, it was difficult to disclose the…

136

Abstract

Purpose

Since the multi-component of powder metallurgy was dispersed, and each component sheared flow and tiered under the action of friction force, it was difficult to disclose the evolution characteristics of each component. Meanwhile, third body mixing with particles of each component covered on the friction surface, which further increased the difficulty of understanding evolution of each component and the corresponding third body in the friction process. To solve this problem, this paper aims to propose a mechanical assembled method which compact several component sheets in order.

Design/methodology/approach

Pure copper, aluminum and artificial graphite sheets with thickness 0.5, 1 and 2 mm, respectively, were assembled into a jig by mechanical compact method. The relationship between arrangement patterns of the components and its friction coefficient was studied by using fixed speed friction test machine, the speed range from 200 to 2,000 r/min and the pressure range from 0.25 to 0.64 MPa.

Findings

The testing results showed that when the distribution of same components was congregated, friction coefficient dropped from 0.6 to 0.4. While the distribution of different components was dispersed, friction coefficient dropped from 0.6 to 0.25. The friction coefficient decline was caused by performances changes of third body fluidity. The sufficiently mixed third body made third body adhesion weaker and increased third body fluidity. That provoked friction coefficient decreasing obviously at high speed. On the contrary, with the high congregation of same components, strong third body adhesion led to a rougher surface which contributed to a higher friction coefficient.

Originality/value

By means of the mechanical-assembled multi-layer components to reveal the influence mechanism of every component on friction properties, will provide a new test approach for tribology.

Details

Industrial Lubrication and Tribology, vol. 68 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 10 December 2019

Xiaoming Zhang, Mingming Meng, Xiaoling Sun and Yu Bai

With the advent of the era of Big Data, the scale of knowledge graph (KG) in various domains is growing rapidly, which holds huge amount of knowledge surely benefiting the…

331

Abstract

Purpose

With the advent of the era of Big Data, the scale of knowledge graph (KG) in various domains is growing rapidly, which holds huge amount of knowledge surely benefiting the question answering (QA) research. However, the KG, which is always constituted of entities and relations, is structurally inconsistent with the natural language query. Thus, the QA system based on KG is still faced with difficulties. The purpose of this paper is to propose a method to answer the domain-specific questions based on KG, providing conveniences for the information query over domain KG.

Design/methodology/approach

The authors propose a method FactQA to answer the factual questions about specific domain. A series of logical rules are designed to transform the factual questions into the triples, in order to solve the structural inconsistency between the user’s question and the domain knowledge. Then, the query expansion strategies and filtering strategies are proposed from two levels (i.e. words and triples in the question). For matching the question with domain knowledge, not only the similarity values between the words in the question and the resources in the domain knowledge but also the tag information of these words is considered. And the tag information is obtained by parsing the question using Stanford CoreNLP. In this paper, the KG in metallic materials domain is used to illustrate the FactQA method.

Findings

The designed logical rules have time stability for transforming the factual questions into the triples. Additionally, after filtering the synonym expansion results of the words in the question, the expansion quality of the triple representation of the question is improved. The tag information of the words in the question is considered in the process of data matching, which could help to filter out the wrong matches.

Originality/value

Although the FactQA is proposed for domain-specific QA, it can also be applied to any other domain besides metallic materials domain. For a question that cannot be answered, FactQA would generate a new related question to answer, providing as much as possible the user with the information they probably need. The FactQA could facilitate the user’s information query based on the emerging KG.

Details

Data Technologies and Applications, vol. 54 no. 1
Type: Research Article
ISSN: 2514-9288

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Article
Publication date: 7 August 2017

XiaoMing Zhou, Qi Song, Yu-yin Li, Huimin Tan and Hang Zhou

The purpose of this paper is to identify the key determinants of the information value of enterprises’ micro-blogs, drawing on the consumer’s perspective. This paper examines the…

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Abstract

Purpose

The purpose of this paper is to identify the key determinants of the information value of enterprises’ micro-blogs, drawing on the consumer’s perspective. This paper examines the effects of such information value on consumers’ purchase intention through the building of online brand equity. The paper also investigates how perceived usefulness intervenes in the relationship between micro-blog information value and consumer purchase intention.

Design/methodology/approach

The proposed research model is examined empirically using a survey of 315 users of the Sina micro-blog. The statistical analysis applies a method based on variance using partial least squares.

Findings

The results show that online retailers’ micro-blog posts, which are characterized by informativeness and persuasiveness as perceived by customers, positively impact online retailers’ brand equity, which in turn influences consumer purchase intention. In addition, perceived information usefulness is found to be an important contextual factor that moderates the relationship between perceived persuasiveness and online retailer brand equity.

Originality/value

This work adds significance to the literature by extending the research on micro-blog marketing and also provides practical recommendations for online retailers on the operation of micro-blogs.

Details

Internet Research, vol. 27 no. 4
Type: Research Article
ISSN: 1066-2243

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Article
Publication date: 7 July 2021

Xiaohua Xin, Xiaoming Miao, Qian Chen and Tiantian Shang

Despite the fact that user participation (UP) has been highlighted as an important aspect in innovation, previous findings on its relationship with service innovation performance…

1044

Abstract

Purpose

Despite the fact that user participation (UP) has been highlighted as an important aspect in innovation, previous findings on its relationship with service innovation performance (SIP) are inconsistent. This study aims to investigate the relationships among UP, knowledge management capability (KMC) and SIP, especially in the digital age, inspired by the theories of knowledge-based and absorptive capacity.

Design/methodology/approach

Based on a sample of 252 Chinese e-commerce enterprises, this study adopts a hierarchical regression analysis and bootstrap method to test the theoretical framework and research hypotheses.

Findings

UP and KMC have positive effects on SIP, respectively. KMC plays a mediating role in the effect of UP on SIP. Furthermore, the intermediary role of KMC varies in different sub-paths between UP and SIP.

Originality/value

First, this study provides some explanations for inconsistent arguments on the relationship between UP and service innovation. Second, with the consideration of specific dimensions of UP and SIP, the mediation role of KMC varies in different sub-paths has been recognized, which provides a deeper understanding of the relationship between UP and SIP. Third, this study opens the discussion about how to realize SIP more effectively in the digital age, advancing theoretical and practical developments on service innovation.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 34 no. 4
Type: Research Article
ISSN: 1355-5855

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Article
Publication date: 6 June 2022

Nazan Colmekcioglu, Denitsa Dineva and Xiaoming Lu

The purpose of this paper is to provide a critical synthesis of research conducted within the hospitality and tourism industries in response to the impact of the COVID-19…

2668

Abstract

Purpose

The purpose of this paper is to provide a critical synthesis of research conducted within the hospitality and tourism industries in response to the impact of the COVID-19 pandemic, identify key perspectives and themes relating to the recovery and resilience of the two sectors and put forward recommendations that help address organizational and consumer behavior changes produced by the pandemic.

Design/methodology/approach

This study adopted a critical reflection approach to identify, select and synthesize relevant research based on which recommendations are drawn.

Findings

This study offers a contemporary framework discussing three distinct themes that emerged from existing research regarding the impact of COVID-19 on the hospitality and tourism industries: management, marketing and consumer behavior.

Practical implications

This study offers operational, practical and actionable recommendations for organizations about how to adapt and recover from the impact of the COVID-19 pandemic by guiding the industry in sustaining long-term resilience.

Originality/value

This study provides a critical and current synthesis of selected literature and theory that discuss key implications of the COVID-19 pandemic for the recovery and resilience-building of the hospitality and tourism sectors.

Details

International Journal of Contemporary Hospitality Management, vol. 34 no. 11
Type: Research Article
ISSN: 0959-6119

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