Dongju Chen, Yueqiang Sun, You Zhao, Kun Sun and Jinwei Fan
The accuracy of the machining process is significantly impacted by the performance of hydrostatic bearings. This paper aims to analyze the influence of micro-textured on the…
Abstract
Purpose
The accuracy of the machining process is significantly impacted by the performance of hydrostatic bearings. This paper aims to analyze the influence of micro-textured on the performance of the hydrostatic bearing, and the performance of the bearing is improved by designing the arrangement of micro-textured.
Design/methodology/approach
Different designs have been used while creating micro-textured bearings. The finite element models of bearing with smooth and micro-textured were established and solved using the computational fluid dynamics method. The arrangement scheme of the micro-textured was evaluated by comparing the influence of the distribution position and arrangement of the micro-textured on the bearing performance.
Findings
To improve the performance of the bearing, the bearing capacity was significantly increased, and the friction coefficient of the bearing was decreased when the micro-textured was distributed in the form of an obtuse angle arrangement in the maximum pressure area of the bearing. The experimental findings validate the analysis method.
Originality/value
In this paper, the effect of irregularly arranged micro-textured on bearing performance is investigated to improve the bearing capacity and lubrication status.
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Peng Wang, Dongju Chen, Jinwei Fan, Kun Sun, Shuiyuan Wu, Jia Li and Yueqiang Sun
The purpose of this paper is to improve the performance and quality of Ti-6Al-4V fabricated by laser powder bed fusion.
Abstract
Purpose
The purpose of this paper is to improve the performance and quality of Ti-6Al-4V fabricated by laser powder bed fusion.
Design/methodology/approach
Single-track experiments were conducted during the fabrication process to obtain the single tracks with excellent wettability to narrow the process parameter window. The effects of process parameters on the build surface, cross-section, relative density, defects, surface roughness, microstructure and mechanical properties of the parts were analyzed through multilayer fabrication experiments and surface optimization experiments.
Findings
The point distance has the greatest influence on the build surface of the fabricated parts, and the unmelted defects can be eliminated when the point distance is 35 µm. The relative density of the fabricated parts decreased with the increase of the point distance, and the hatch spacing has different characteristics with respect to the relative density of the fabricated parts under different laser powers. It was observed that the most of experimental groups with higher relative densities than 99%, and the highest density could reach 99.99%. The surface roughness can be reduced to less than 10 µm through remelting optimization.
Originality/value
The research results can provide theoretical support for scientific researchers and data support for engineers.
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Dongju Chen, Yupeng Zhao, Kun Sun, Ri Pan and Jinwei Fan
To enhance the performance of hydrostatic bearings, graphene serves as a lubricant additive. Using the high thermal conductivity of graphene, the purpose of this study is to focus…
Abstract
Purpose
To enhance the performance of hydrostatic bearings, graphene serves as a lubricant additive. Using the high thermal conductivity of graphene, the purpose of this study is to focus on the impact of graphene nano-lubricating oil hydrostatic bearing temperature rise at various speeds and eccentricities.
Design/methodology/approach
The thermal conductivity of graphene nano-lubricating oil was calculated by molecular dynamics method and based on the viscosity–temperature effect, the coupled heat transfer finite element model of hydrostatic bearing was established; temperature rise of pure lubricating oil and graphene nano-lubricating oil hydrostatic bearing were analysed at different speed and eccentricity based on computational fluid dynamics method.
Findings
With the increase of speed and eccentricity, the temperature rise of 0.2% graphene nano-lubricating oil bearings is lower than that of pure lubricating oil bearings; in addition with the increase of graphene mass fraction, the temperature rise of graphene nano-lubricating oil bearings is always higher than that of pure lubricating oil bearings, and the higher the speed, the more obvious the phenomenon.
Originality/value
The effects of graphene as a lubricant additive on the thermal conductivity of nano-lubricating oil and the variation of the temperature rise of graphene nano-lubricating oil bearings compared to pure lubricating oil bearings were analysed by combining micro and macro methods.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2023-0388
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Dongju Chen, Xuan Zhang, Kun Sun and Jinwei Fan
This paper aims to study the influence degree of three factors affecting the vibration amplitude of aerostatic spindle and optimizes each factor.
Abstract
Purpose
This paper aims to study the influence degree of three factors affecting the vibration amplitude of aerostatic spindle and optimizes each factor.
Design/methodology/approach
The vibration amplitude of the spindle is characterized according to internal structure and operating characteristics of aerostatic spindle. The radial and axial vibration models of aerostatic spindle were established by the spring-damper system. The influence degree of main influencing factors on the spindle vibration amplitude was investigated through correlation analysis.
Findings
The results indicate that the crucial factor is aerostatic spindle speed and experiments validated that increasing spindle speed can enhance spindle stability. The influence of three factors on radial vibration is greater than that on axial vibration. Finally, the values of optimal working parameters were obtained by genetic algorithm.
Originality/value
The method in this article can effectively predict aerostatic spindle vibration amplitude and perfect the stability of aerostatic spindle.
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Dongju Chen, Xuan Zhang, Ri Pan, Kun Sun and Jinwei Fan
This research aims to combine the throttling structure with the elastic element to enhance the load performance of aerostatic radial bearing.
Abstract
Purpose
This research aims to combine the throttling structure with the elastic element to enhance the load performance of aerostatic radial bearing.
Design/methodology/approach
In this research, a fluid–solid coupling model of the elastic throttling structure is established while considering the interaction between the elastic element and the flow field. The effects of elastic element structural parameters on the stiffness and load capacity of aerostatic radial bearing are then researched. Finally, the effect of elastic element modulus on air film load performance and elastic element deformation is analyzed.
Findings
The results indicate that the aerostatic radial bearing with elastic element can significantly improve the load capacity and stiffness when compared to the common aerostatic bearing. By choosing the proper combination of parameters, the load performance can be improved by at least 16%.
Originality/value
The throttling structure of aerostatic bearing is optimized in this work, which significantly enhances the load performance of the aerostatic bearing.
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Zhaoyang Sun, Haiyang Zhou, Tianchen Yang, Kun Wang and Yubo Hou
The shape of a product plays a crucial role in shaping consumer behavior. Despite the voluminous research on factors influencing consumers’ shape preferences, there remains a…
Abstract
Purpose
The shape of a product plays a crucial role in shaping consumer behavior. Despite the voluminous research on factors influencing consumers’ shape preferences, there remains a limited understanding of how the busy mindset, a mentality increasingly emphasized by marketing campaigns, works. This study aims to fill this gap by exploring the relationship between a busy mindset and the preference for angular-shaped versus circular-shaped products and brand logos.
Design/methodology/approach
This research consists of seven experimental studies using various shape stimuli, distinct manipulations of busy mindset, different assessments of shape preference and samples drawn from multiple countries.
Findings
The findings reveal that a busy mindset leads to a preference for angular shapes over circular ones by amplifying the need for uniqueness. In addition, these effects are attenuated when products are scarce.
Originality/value
This research represents one of the pioneering efforts to study the role of a busy mindset on consumers’ aesthetic preferences. Beyond yielding insights for practitioners into visual marketing, this research contributes to the theories on the busy mindset and shape preference.
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Kun Sun, Dichen Li, Haihua Wu, Minjie Wang and Xiaoyong Tian
The purpose of this paper is to bring up the concept of multi‐material electromagnetic band‐gap structure (EBGs) and develop a method for its fabrication. Meanwhile, its microwave…
Abstract
Purpose
The purpose of this paper is to bring up the concept of multi‐material electromagnetic band‐gap structure (EBGs) and develop a method for its fabrication. Meanwhile, its microwave properties were studied and compared with the traditional EBGs consisting of two kinds of material.
Design/methodology/approach
Stereolithography (SL) and gel casting were used to fabricate 3D multi‐material EBGs. Resin mold was designed and fabricated based on SL process, slurries loaded with 55vol per cent Al2O3 and 55vol per cent TiO2, respectively, were prepared, and using gel casting, multilayer EBGs with diamond structure were fabricated. T/R method was used to obtain the characteristic parameter S21 of the EBGs; meanwhile, characters of their band structure were studied based on plane wave expansion method.
Findings
The fabricated EBGs with a TiO2‐resin‐air structure showed a band gap from 11.7 GHz to 16.0 GHz along <1, 1, 0> direction; the EBGs with a TiO2‐resin‐Al2O3 structure showed a band gap from 11.4 GHz to 11.9 GHz along <1, 1, 0> direction. Both of them agreed well with the simulation result. Also, through the study of multi‐material EBGs' microwave properties, it could be seen that this structure was a good approach to adjust the band gap.
Originality/value
With the concept of multi‐material EBG structure brought up, multilayer 3D EBGs were designed and fabricated based on SL combined with gel casting. It could be seen that multi‐material EBGs was a good approach to adjust the band gap. Also, the fact that the testing result matched the simulation validates the feasibility of the process.
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Kun Sun, Bo Li, Liang Fang and Qingguang Ye
Expanded polystyrene (EPS) is a low‐density and cheap material, which has been widely used in commercial areas. As the demand for small‐batch, flexible and quick production…
Abstract
Purpose
Expanded polystyrene (EPS) is a low‐density and cheap material, which has been widely used in commercial areas. As the demand for small‐batch, flexible and quick production increases, producing EPS products with metals moulds has become unaffordable. The purpose of this paper is to describe the development of an EPS rapid prototyping (ERP) process, with an electric heating tool.
Design/methodology/approach
Two new cutting strategies for the ERP process, constant angle mode and constant thickness mode, are proposed. The methods to generate tool path of those models are also discussed. In order to improve accuracy and cutting effectiveness, experiments have been carried out to investigate the thermal characteristics in the ERP process. Consequently, the relationships between the size of material removal area and process parameters are obtained. Suitable processing parameters for the ERP system are also conducted.
Findings
It is found that the ERP process can rapidly produce complex three‐dimensional parts in one‐off clamping without post‐processing procedures as in traditional rapid prototyping, such as, extra support removing, step texture finishing and distortion regulating.
Originality/value
The paper provides several examples to explain and illustrate the applicability and workflow of the ERP system.
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Keywords
Guojun Zeng, Frank Go and Christian Kolmer
This study aims to explain the impact of the Beijing Olympic Games 2008 on China's image in the international TV media. It applies agenda-setting theory to analyse foreign TV…
Abstract
This study aims to explain the impact of the Beijing Olympic Games 2008 on China's image in the international TV media. It applies agenda-setting theory to analyse foreign TV coverage of the Olympics in nine countries. Using Rivenburgh's national image richness construct, it attempts to make sense of the coverage before and after Beijing 2008, particularly its impact on the image of the host country. The study concludes that the breadth and attribution of China's image remained relatively stable, that these factors did not improve China's national image directly but that indirectly they raised awareness of China in the international media and framed the host country's image more clearly.
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Tianyun Shi, Zhoulong Wang, Jia You, Pengyue Guo, Lili Jiang, Huijin Fu and Xu Gao
The safety of high-speed rail operation environments is an important guarantee for the safe operation of high-speed rail. The operating environment of the high-speed rail is…
Abstract
Purpose
The safety of high-speed rail operation environments is an important guarantee for the safe operation of high-speed rail. The operating environment of the high-speed rail is complex, and the main factors affecting the safety of high-speed rail operating environment include meteorological disasters, perimeter intrusion and external environmental hazards. The purpose of the paper is to elaborate on the current research status and team research progress on the perception of safety situation in high-speed rail operation environment and to propose directions for further research in the future.
Design/methodology/approach
In terms of the mechanism and spatio-temporal evolution law of the main influencing factors on the safety of high-speed rail operation environments, the research status is elaborated, and the latest research progress and achievements of the team are introduced. This paper elaborates on the research status and introduces the latest research progress and achievements of the team in terms of meteorological, perimeter and external environmental situation perception methods for high-speed rail operation.
Findings
Based on the technical route of “situational awareness evaluation warning active control,” a technical system for monitoring the safety of high-speed train operation environments has been formed. Relevant theoretical and technical research and application have been carried out around the impact of meteorological disasters, perimeter intrusion and the external environment on high-speed rail safety. These works strongly support the improvement of China’s railway environmental safety guarantee technology.
Originality/value
With the operation of CR450 high-speed trains with a speed of 400 km per hour and the application of high-speed train autonomous driving technology in the future, new and higher requirements have been put forward for the safety of high-speed rail operation environments. The following five aspects of work are urgently needed: (1) Research the single factor disaster mechanism of wind, rain, snow, lightning, etc. for high-speed railways with a speed of 400 kms per hour, and based on this, study the evolution characteristics of multiple safety factors and the correlation between the high-speed driving safety environment, revealing the coupling disaster mechanism of multiple influencing factors; (2) Research covers multi-source data fusion methods and associated features such as disaster monitoring data, meteorological information, route characteristics and terrain and landforms, studying the spatio-temporal evolution laws of meteorological disasters, perimeter intrusions and external environmental hazards; (3) In terms of meteorological disaster situation awareness, research high-precision prediction methods for meteorological information time series along high-speed rail lines and study the realization of small-scale real-time dynamic and accurate prediction of meteorological disasters along high-speed rail lines; (4) In terms of perimeter intrusion, research a multi-modal fusion perception method for typical scenarios of high-speed rail operation in all time, all weather and all coverage and combine artificial intelligence technology to achieve comprehensive and accurate perception of perimeter security risks along the high-speed rail line and (5) In terms of external environment, based on the existing general network framework for change detection, we will carry out research on change detection and algorithms in the surrounding environment of high-speed rail.