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1 – 10 of 12Zeyuan Zhou, Ying Wang and Zhijie Xia
This study aims to further refine the model, explore the influence of cutting parameters on the machining process, and apply it to practical engineering to improve the efficiency…
Abstract
Purpose
This study aims to further refine the model, explore the influence of cutting parameters on the machining process, and apply it to practical engineering to improve the efficiency and quality of titanium alloy machining.
Design/methodology/approach
This paper establishes a comprehensive thermo-mechanical fully coupled orthogonal cutting model. This paper aims to couple the modified Johnson–Cook constitutive model, damage model and contact model to construct a two-dimensional orthogonal cutting thermo-mechanical coupling model for high-speed cutting of Ti6Al4V. The model considers the evolution of microstructures such as plastic deformation, grain dislocation rearrangement, dynamic recrystallization, as well as stress softening and hardening occurring continuously in Ti6Al4V metal during high-speed cutting. Additionally, the model incorporates friction and contact between the tool and the workpiece. It can be used to predict parameters such as cutting process, cutting force, temperature distribution, stress and strain in titanium alloy machining. The study establishes the model and implements corresponding functions by writing Abaqus VUMAT and VFRICTION subroutines.
Findings
The use of different material constitutive models can significantly impact the prediction of the cutting process. Some models may more accurately describe the mechanical behavior of the material, thus providing more reliable prediction results, while other models may exhibit larger deviations. Compared to the Tanh model, the proposed model achieves a maximum improvement of 8.9% in the prediction of cutting force and a maximum improvement of 20.9% in the prediction of chip morphology parameters. Compared to experiments, the proposed model achieves a minimum prediction error of 2.8% for average cutting force and a minimum error of 0.57% for sawtooth parameters. This study provides a comprehensive theoretical foundation and practical guidance for orthogonal cutting of titanium alloys. The model not only helps engineers and researchers better understand various phenomena in the cutting process but also serves as an important reference for optimizing cutting processes.
Originality/value
The originality of this research is guaranteed, as it has not been previously published in any journal or publication.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0168/
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Zeyuan Zhou, Ying Wang and Zhijie Xia
This study aims to establish a thermally coupled two-dimensional orthogonal cutting model to further improve the modeling process for systematic evaluation of material damage…
Abstract
Purpose
This study aims to establish a thermally coupled two-dimensional orthogonal cutting model to further improve the modeling process for systematic evaluation of material damage, stiffness degradation, equivalent plastic strain and other material properties, along with cutting temperature distribution and cutting forces. This enhances modeling efficiency and accuracy.
Design/methodology/approach
A two-dimensional orthogonal cutting thermo-mechanical coupled finite element model is established in this study. The tanh material constitutive model is used to simulate the mechanical properties of the material. Velocity-dependent friction model between the workpiece and the tool is considered. Material characteristics such as material damage, stiffness degradation, equivalent plastic strain and temperature field during cutting are evaluated through computation. Contact pressure and shear stress on the tool surface are extracted for friction analysis.
Findings
Speed-dependent friction models predict cutting force errors as low as 8.6%. The prediction errors of various friction models increase with increasing cutting forces and depths of cut, and simulation results tend to be higher than experimental data.
Social implications
The current research results provide insights into understanding and controlling tool-chip friction in metal cutting, offering practical recommendations for friction modeling and machining simulation work.
Originality/value
The originality of this research is guaranteed, as it has not been previously published in any journal or publication.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0162/
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Abstract
Purpose
With a mass of electronic multi-topic documents available, there is an increasing need for evaluating emerging analysis tools to help users and digital libraries analyze these documents better. The purpose of this paper is to evaluate the effectiveness, efficiency and user satisfaction of THC-DAT, a within-document analysis tool, in reading a multi-topic document.
Design/methodology/approach
The authors reviewed related literature first, then performed a user-centered, comparative evaluation of two within-document analysis tools, THC-DAT and BOOKMARK. THC-DAT extracts a topic hierarchy tree using hierarchical latent Dirichlet allocation (hLDA) method and takes the context information into account. BOOKMARK provides similar functionality to the Table of Contents bookmarks in Adobe Reader. Three novel kinds of tasks were devised for participants to finish on two tools, with objective results to assess reading effectiveness and efficiency. And post-system questionnaires were employed to obtain participants’ subjective judgments about the tools.
Findings
The results confirm that THC-DAT is significantly more effective than BOOKMARK, while not inferior in efficiency. There is some evidence that suggests THC-DAT can slow down the process of approaching cognitive overload and improve users’ willingness to undertake difficult task. Based on qualitative data from questionnaires, the results indicate that users were more satisfied when using THC-DAT than BOOKMARK.
Practical implications
Adopting THC-DAT in digital libraries or electrical document reading systems contributes to promoting users’ reading performance, willingness to undertake difficult task and general satisfaction. Moreover, THC-DAT is of great value to addressing cognitive overload problem in the information retrieval field.
Originality/value
This paper evaluates a novel within-document analysis tool in analyzing a multi-topic document, and proved that this tool is superior to the benchmark in effectiveness and user satisfaction, and not inferior in efficiency.
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Sihui Li, Yajing Bu, Zeyuan Zhang and Yangjie Huang
With the development of the digital economy, digital entrepreneurship has become increasingly popular. For college students preparing for digital entrepreneurship, it is necessary…
Abstract
Purpose
With the development of the digital economy, digital entrepreneurship has become increasingly popular. For college students preparing for digital entrepreneurship, it is necessary to cope with the uncertainty of the start-up process through meaningful managing learning and continuous entrepreneurship education. The purpose of this study is to examine the relationship between Chinese college students' digital entrepreneurship intention and digital entrepreneurship behavior, as well as the role of managing learning and entrepreneurship education in this relationship.
Design/methodology/approach
Based on the existing literature, this study established the digital entrepreneurship hypothesis model and investigated the digital entrepreneurship behavior of college students.
Findings
The results showed that managing learning and entrepreneurship education can promote the transformation of the digital entrepreneurship intention to digital entrepreneurship behavior. Managing learning and entrepreneurship education played a driving role in the transformation of the digital entrepreneurship intention to digital entrepreneurship behavior.
Originality/value
This study explored the complex mechanism of the relationship between digital entrepreneurship intention and digital entrepreneurship behavior among Chinese college students. Based on survey data from 235 college students in China, the empirical results supported theoretical research hypotheses on the relationship between college students and digital entrepreneurship intention, digital entrepreneurship behavior, managing learning and entrepreneurship education.
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Linfeng Deng, Jie Su and Zeyuan Jin
The purpose of this paper is to study the impact of different types of textures on the friction lubrication performance of cylindrical roller bearings.
Abstract
Purpose
The purpose of this paper is to study the impact of different types of textures on the friction lubrication performance of cylindrical roller bearings.
Design/methodology/approach
In the present study, the composite texture hydrodynamic lubrication model that takes into account the effects of surface roughness is established, and the Reynolds equation for the oil film is numerically solved using the finite difference method. The study investigates the oil film carrying capacity and maximum pressure of bearings under two different arrangements of four composite textures and conducts a comparative analysis of the oil film characteristics under various texture parameters and surface roughness levels.
Findings
When the roughness of the inner texture surface and the contact surface are equal, the bearing capacity of the composite texture is intermediate between the two textures. The impact trend of surface roughness on fluid dynamic pressure effects varies with the type of composite texture; the internal roughness of the texture affects the micro-hydrodynamic pressure action. Composite textures with different depths exhibit improved bearing capacities; elliptical cylindrical parallel and elliptical hemispherical parallel textures perform better when their area densities are similar, while other types of composite textures show enhanced bearing performance as the ratio of their area densities increases.
Originality/value
This paper contributes to the theoretical investigations and analyses on designing the textured rolling bearings with high lubrication performance.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2024-0050
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Wenbin Xu, Xudong Li, Liang Gong, Yixiang Huang, Zeyuan Zheng, Zelin Zhao, Lujie Zhao, Binhao Chen, Haozhe Yang, Li Cao and Chengliang Liu
This paper aims to present a human-in-the-loop natural teaching paradigm based on scene-motion cross-modal perception, which facilitates the manipulation intelligence and robot…
Abstract
Purpose
This paper aims to present a human-in-the-loop natural teaching paradigm based on scene-motion cross-modal perception, which facilitates the manipulation intelligence and robot teleoperation.
Design/methodology/approach
The proposed natural teaching paradigm is used to telemanipulate a life-size humanoid robot in response to a complicated working scenario. First, a vision sensor is used to project mission scenes onto virtual reality glasses for human-in-the-loop reactions. Second, motion capture system is established to retarget eye-body synergic movements to a skeletal model. Third, real-time data transfer is realized through publish-subscribe messaging mechanism in robot operating system. Next, joint angles are computed through a fast mapping algorithm and sent to a slave controller through a serial port. Finally, visualization terminals render it convenient to make comparisons between two motion systems.
Findings
Experimentation in various industrial mission scenes, such as approaching flanges, shows the numerous advantages brought by natural teaching, including being real-time, high accuracy, repeatability and dexterity.
Originality/value
The proposed paradigm realizes the natural cross-modal combination of perception information and enhances the working capacity and flexibility of industrial robots, paving a new way for effective robot teaching and autonomous learning.
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Hekun Jia, Zeyuan Zhou, Bifeng Yin, Huiqin Zhou and Bo Xu
The purpose of this study is to investigate the influence of dimple radius, depth and density on the lubrication performance of the plunger.
Abstract
Purpose
The purpose of this study is to investigate the influence of dimple radius, depth and density on the lubrication performance of the plunger.
Design/methodology/approach
A lubrication model was adopted to consider eccentricity and deformation during the working process of the plunger, and a rig test was performed to confirm the simulation results. The texture was fabricated using laser surface texturing.
Findings
The simulation results suggested that when dimple radius or depth increases, oil film thickness of the plunger increases before decreasing, and asperity friction displays an opposite trend. Therefore, appropriate microdimple texture could facilitate lubrication performance improvement and reduce the wear. Microdimples were then lased on the plunger surface, and a basic tribological test was conducted to validate the simulation results. The experimental results suggested that the average friction coefficient decreased from 0.18 to 0.13, a reduction of 27.8%.
Social implications
The introduction of microdimple on a plunger couple to reduce friction and improve lubrication is expected to provide a new approach to developing high-performance plunger couple and improve the performance of the internal combustion engine. If applied, the surface texture could help reduce friction by around 27% and cap the cost relative to the plugger friction.
Originality/value
The microdimple texture was introduced into the plunger couple of a vehicle to reduce the friction and improve the performance. Findings suggested that surface texture could be used in the automotive industry to improve oil efficiency and lubrication performance.
Peer review
The peer review history for this article is available at: http://dx.doi.org/10.1108/ILT-07-2020-0259.
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Yue Chen and Zeyuan Liu
The purpose of this paper is to recognize the concepts and disciplinary position of management, for faculty members in management circles, which can help them develop their…
Abstract
Purpose
The purpose of this paper is to recognize the concepts and disciplinary position of management, for faculty members in management circles, which can help them develop their academic career.
Design/methodology/approach
Based on review and clarification of domestic and international disciplinary concepts on management, this paper takes data from academic journals of international management as the sample, making use of the latest mapping knowledge domains method.
Findings
Reveals the disciplinary boundary of modern management and disciplinary position of general management as a basic discipline, demonstrates the relationship between management and other relevant disciplines, such as psychology, sociology, economics, mathematics, etc. shows the trend of ascending position of management in mankind's knowledge system as an independent discipline.
Originality/value
This paper identifies concepts and information in management sciences which will provide inspiration for management in China, to move forward to the international academic frontline.
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Shenmeng Xu, Xianwen Wang, Zeyuan Liu and Chunjuan Luan
– The purpose of this paper is to analyze the network structure of technology in and between different fields, as well as the evolution of their relations.
Abstract
Purpose
The purpose of this paper is to analyze the network structure of technology in and between different fields, as well as the evolution of their relations.
Design/methodology/approach
Using the patent data in Derwent Innovation Index (DII) from 1991 to 2010, this paper analyzes the co-classification of Derwent Manual Code (DMC) of patents in all technology fields. Large-scaled co-classification matrices are employed to generate the DMC co-classification networks. In addition, analyses are pursued at different levels of aggregation in four five-year windows: 1991-1995, 1996-2000, 2001-2005 and 2006-2010. Using Girvan-Newman algorithm in the clustering process, the structure transformations over time are detected.
Findings
The paper identifies the key technological knowledge in certain fields and finds out how different technological fields are connected and integrated. What is more, the dynamic evolution between networks in different time periods reveals the trend of generic technology development in the macroscopic level.
Originality/value
The paper investigates a large quantity of data – all the patent data in DII from 1991 to 2010 in this paper. The paper applies Girvan-Newman algorithm in the co-classification analysis and uses co-classification networks to reveal technology network structures. Evolution coincident with the realistic technological shifts can be observed.
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Yang Can and Angela Yung Chi Hou
The advance in higher education in Asian countries is of major interest because it reveals increasing global political and cultural influence in recent years. The review explores…
Abstract
Purpose
The advance in higher education in Asian countries is of major interest because it reveals increasing global political and cultural influence in recent years. The review explores the characteristics of publications from 2013–2018 concerned with the internationalisation of higher education in Asia. The study aims to analyse the current trajectory, including the size, growth trends, and regional networking of this domain, with a goal of identifying the influential journals, authors, and documents, as well exploring the thematic structure and topical issues and trends of this domain.
Design/methodology/approach
241 Scopus-indexed documents were selected and reviewed using a quantitative descriptive way. These documents were analysed by VOS viewer software.
Findings
The results show the most topical issues and trends concern about “Asian immigration and mobility”, “transnational education”, “international students and acculturation”, and “international branch campuses”. Seven main schools of thought were identified and are clearly explained herein, which provides a baseline for future research for new scholars.
Social implications
The present study suggests that trans-regional cooperation is the future of internationalisation in higher education. Asian scholars are recommended to increase cooperation and exchanges with each other, expand channels of contact, further understand and optimise their own advantages, achieve win-win cooperation and make Asia's voice heard in the world in higher education field.
Originality/value
This bibliometric review can predict the main trends in higher education internationalisation in the future and encourage implication of interdisciplinary research in higher education internationalisation.
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