To further understand the granular flow lubrication mechanism in metal contact pairs, the effect of sliding-rolling ratio on the force chain properties was investigated.
Abstract
Purpose
To further understand the granular flow lubrication mechanism in metal contact pairs, the effect of sliding-rolling ratio on the force chain properties was investigated.
Design/methodology/approach
The parallel inter-plate model of the granular flow lubrication was established with discrete element method. Then, the correlation law between sliding-rolling ratio and force chain evolution properties was calculated and analyzed with PFC2D software platform.
Findings
Numerical calculation results show that the dynamic fluctuation property of force chain is existed, and the shock frequency of it is increased with the increase of sliding-rolling ratio. The same evolution law is also occurred for the bearing rate of strong force chain in the initial expansion and final compression phases, and the opposite phenomena is obtained for the overall expansion phase. Moreover, the directivity of strong force chain is changed by the sliding-rolling ratio. With the increase of sliding-rolling ratio, the directivity of strong force chain is first tended to y-axis, and then inclined to the x-axis in the whole phases. The basic reason is that a clamping up and downward movement impact for the neighbor particles are the essence of the above phenomenon.
Originality/value
The main contribution of this work is to lay a theory foundation of interfacial lubrication mechanism with granular flow.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0133/
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Wenchao Zhang, Enming Cui, Cheng Wang, Baoquan Zhang, Jiwei Jin, Pengfei Zhang, Wending Wu and Mingwei Wang
An investigation was conducted into the impact of various process parameters on the surface and subsurface quality of glass-ceramic materials, as well as the mechanism of material…
Abstract
Purpose
An investigation was conducted into the impact of various process parameters on the surface and subsurface quality of glass-ceramic materials, as well as the mechanism of material removal and crack formation, through the use of ultrasonic-assisted grinding.
Design/methodology/approach
A mathematical model of crack propagation in ultrasonic-assisted grinding was established, and the mechanism of crack formation was described through the model. A series of simulations and experiments were conducted to investigate the impact of process parameters on crack depth, surface roughness, and surface topography during ultrasonic-assisted surface and axial grinding. Additionally, the mechanism of crack formation was explored.
Findings
During ultrasonic-assisted grinding, the average grinding forces are between 0.4–1.0 N, which is much smaller than that of ordinary grinding (1.0–3.5 N). In surface grinding, the maximum surface stresses between the workpiece and the tool gradually decrease with the tool speed. The surface stresses of the workpiece increase with the grinding depth, and the depth of subsurface cracks increases with the grinding depth. With the increase of the axial grinding speed, the subsurface damage depth increases. The roughness increases from 0.780um/1.433um.
Originality/value
A mathematical model of crack propagation in ultrasonic-assisted grinding was established, and the mechanism of crack formation was described through the model. The deformation involved in the grinding process is large, and the FEM-SPH modeling method is used to solve the problem that the results of the traditional finite element method are not convergent and the calculation efficiency is low.
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Huizhong Zhang, Yu Zuo, Pengfei Ju, Jian Zhang, Xuhui Zhao, Yuming Tang and Xiaofeng Zhang
The purpose of this paper is to study the variations of composition and properties of the passive film on 316 L stainless steel surface in 80°C, 0.5 mol L-1 H2SO4 + 2 mg L-1 NaF…
Abstract
Purpose
The purpose of this paper is to study the variations of composition and properties of the passive film on 316 L stainless steel surface in 80°C, 0.5 mol L-1 H2SO4 + 2 mg L-1 NaF solution, is helpful to understand the mechanisms of corrosion resistancethe of plated Pd on 316 L ss.
Design/methodology/approach
The variations of composition and properties of the passive film on 316 L stainless steel surface in 80°C, 0.5 mol L-1 H2SO4 + 2 mg L-1 NaF solution after connected to Pd electrode were studied with methods of potential monitor, X-ray photoelectron spectroscopy analysis and electrochemical impedance spectrum (EIS) measurement.
Findings
By connecting to a Pd electrode, the potential of the SS sample increased from the active region to the passive region. By connecting to the Pd electrode, the contents of Cr, Cr(OH)3 and Fe3O4 in passive film increased obviously. With increased Pd/SS area ratio, the Cr(OH)3 content in passive film increased but the Fe3O4 content changed little. The results show that after connecting to Pd the corrosion resistance of the passive film on 316 L stainless steel increases obviously, which may be attributed to the more compact passive film because of higher Cr, Cr(OH)3 and Fe3O4 contents and less point defects in the film.
Originality/value
The effects and mechanism of Pd on passivation of SS was studied.
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Jing Luan, Jie Xiao, Pengfei Tang and Meng Li
A counterintuitive finding of existing research is that negative reviews can produce positive effects; for example, they can increase purchase likelihood and sales by increasing…
Abstract
Purpose
A counterintuitive finding of existing research is that negative reviews can produce positive effects; for example, they can increase purchase likelihood and sales by increasing product awareness. It is important to continue highlighting this fact and to develop further insights into this positive effect, as a more thorough analysis can provide online retailers with a more comprehensive understanding of how to effectively manage and use negative reviews. Thus, by using an eye-tracking method, this paper attempts to provide a further thorough analysis of positive effects of negative reviews from a cognitive perspective.
Design/methodology/approach
An eye-tracking experiment with two tests over a time delay was performed to examine whether negative reviews have some positive effects. Review valence (positive vs. negative), brand popularity (popular vs. unpopular) and advertising exposure (no repetition vs. repetition) were considered in the experiment.
Findings
The results show that a cognitive process of attention allocation happens when consumers deal with brand popularity cues and that arousal evoking and attention allocation occur when handling review valence. Allocation of more attention to unpopular brands helps improve brand awareness and enhance brand memory, and larger arousal from negative reviews narrows attention and leads to a better memory of products and brands. However, with the passage of time, the memory of review valence can dissociate and fade, and the remaining awareness of and familiarity with unpopular brands with negative reviews contribute to a positive reversion, which leads to the production of positive effects from negative reviews.
Originality/value
This paper contributes to the literature on online reviews by examining the visual processing of review valence and brand popularity with an eye-tracking method and by revealing the cognitive mechanism of positive effects of negative reviews from a visual attention perspective.
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Kai Wang, Xiang Wang, Chao Tan, Shijie Dong, Fang Zhao and Shiguo Lian
This study aims to streamline and enhance the assembly defect inspection process in diesel engine production. Traditional manual inspection methods are labor-intensive and…
Abstract
Purpose
This study aims to streamline and enhance the assembly defect inspection process in diesel engine production. Traditional manual inspection methods are labor-intensive and time-consuming because of the complex structures of the engines and the noisy workshop environment. This study’s robotic system aims to alleviate these challenges by automating the inspection process and enabling easy remote inspection, thereby freeing workers from heavy fieldwork.
Design/methodology/approach
This study’s system uses a robotic arm to traverse and capture images of key components of the engine. This study uses anomaly detection algorithms to automatically identify defects in the captured images. Additionally, this system is enhanced by digital twin technology, which provides inspectors with various tools to designate components of interest in the engine and assist in defect checking and annotation. This integration facilitates smooth transitions from manual to automatic inspection within a short period.
Findings
Through evaluations and user studies conducted over a relatively long period, the authors found that the system accelerates and improves the accuracy of engine inspections. The results indicate that the system significantly enhances the efficiency of production processes for manufacturers.
Originality/value
The system represents a novel approach to engine inspection, leveraging robotic technology and digital twin enhancements to address the limitations of traditional manual inspection methods. By automating and enhancing the inspection process, the system offers manufacturers the opportunity to improve production efficiency and ensure the quality of diesel engines.
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Xuewei Fang, Zhengying Wei, Jun Du, Lu Bingheng, Pengfei He, Bowen Wang, Jian Chen and Ruwei Geng
This paper aimed to propose a novel fused-coating-based additive manufacturing (FCAM); the study of key process parameters and mechanical tests are performed to determine the…
Abstract
Purpose
This paper aimed to propose a novel fused-coating-based additive manufacturing (FCAM); the study of key process parameters and mechanical tests are performed to determine the proper parameters when building metal components.
Design/methodology/approach
Sn63Pb37 alloy is deposited in an induction heating furnace with a fused-coating nozzle to build metal parts on a copper-clad substrate. The process parameters including nozzle pressure, nozzle and substrate temperature and nozzle gap between substrate are analyzed and found to have great influence on parts quality. The mechanical property tests between the fused-coating and casting parts are performed in horizontal and vertical directions. Also, the optical microscopy images are used to ascertain under which conditions good bonding can be achieved.
Findings
A FCAM method is proposed, and the exploration study about the manufacturing process is carried out. The critical parameters are analyzed, and microscopy images prove the suitable temperature range that requires to fabricate metal parts. The mechanical tests confirm that tensile strength of printing parts is improved by 20.4 and 11.9 per cent in horizontal and vertical direction than casting parts. The experimental results indicate that there is a close relationship between process parameters and mechanical properties.
Originality/value
This paper proves that FCAM provides an alternative way to quickly make functional metal parts with good quality and flexibility compared with other additive manufacturing methods. Moreover, good mechanical property is achieved than conventional casting parts.
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Hongjing Dong, Xi Chen, Guangying Yang, Dandan He, Ying Dai and Pengfei He
The purpose of this paper is to obtain a constitutive model of cement-based material in the rheological stage, which owns the different water-cement ratio (w/c) and temperature…
Abstract
Purpose
The purpose of this paper is to obtain a constitutive model of cement-based material in the rheological stage, which owns the different water-cement ratio (w/c) and temperature and have a significant impact on the workability of concrete materials.
Design/methodology/approach
It is introduced a modified Arrhenius equation into the Herschel–Bulkley model, which is widely applied in rheological analysis and constructed an ordinary differential equation (ODE) of w/c from the Navier–Stokes equation. By solving the ODE, an approximate constitutive relation of cement-based materials included w/c and temperature is derived. Compared with the experimental results, the present model is validated.
Findings
The shear stress and shear rate curves with different w/c and temperature are simulated by the present method, and the present model can be applied to analyze the changes of apparent viscosity in cement-based material slurry as the w/c and temperature varying.
Originality/value
This work gives a mathematical model, which can effectively approximate the shear stress–shear rate relation with different w/c and temperature in the rheological stage of cement-based material.
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Pengfei Deng, Peng Zheng and Dan Xie
The issue of excessive carbon emissions continues to be a critical global challenge. As a prominent mode of transportation for long-distance travel, aircraft is widely…
Abstract
Purpose
The issue of excessive carbon emissions continues to be a critical global challenge. As a prominent mode of transportation for long-distance travel, aircraft is widely acknowledged as a significant source of these emissions. Carbon offset initiatives function as ecological measures, helping to reduce the negative environmental impact. This study aims to explore how benefit appeals (BA) within the aviation industry impact tourists’ carbon offset payment intentions (COPIt).
Design/methodology/approach
In Studies 1 and 2, scenario-based experiments were conducted to explore how goal framing (GF) and (BA) interact to influence COPIt. Study 2 further investigated the mediating roles of moral responsibility and trust in airlines within this interaction. Study 3 used real-world surveys to examine the moderating influence of moral elevation, thereby supporting the interactive effects and mediation mechanisms identified in the earlier studies.
Findings
Across three studies, the authors consistently identified pivotal factors shaping COPIt in the context of air travel. Study 1 revealed that the combination of BA and GF significantly impacts COPIt, with egoistic appeals linked to loss framing and altruistic appeals connected to gain framing being particularly effective in encouraging COPIt. Study 2 extended these insights by showing that moral responsibility and trust in airlines serve as mediators between BA, GF and COPIt. In Study 3, moral elevation was found to moderate the influence of BA and GF on both moral responsibility and COPIt, deepening the understanding of these dynamics.
Originality/value
This study expands the range of factors affecting COPIt and delves into the underlying mechanisms through which BA and GF shape COPIt. Additionally, it advances current understanding by revealing the intricate processes influenced by moral elevation. The findings not only contribute to the existing knowledge on COPIt determinants but also offer practical guidance for the aviation industry and related sectors in promoting tourists’ participation in carbon offset programs.
研究目的
本研究探讨航空业中不同利益诉求(利他 vs. 利己)和目标框架(收益 vs. 损失)如何影响游客的碳补偿支付意向, 以应对航空业作为主要碳排放源的环境挑战。
设计/方法
通过三项实验分析利益诉求与目标框架对碳补偿支付意向的影响, 前两项研究探讨利益诉求与目标框架的交互作用以及道德责任感和信任的中介作用, 第三项在机场调研中考察道德提升感的调节作用。
发现
结果显示, 利他诉求与收益框架、利己诉求与损失框架的匹配显著提高游客的支付意向, 道德责任感和信任为中介, 且道德提升感调节了这一影响。
原创性/价值
本研究丰富了碳补偿支付意向的理论, 揭示利益诉求与目标框架的交互作用机制, 并为航空业提供了有效推动碳补偿项目的实践建议。
Objetivo del studio
Este estudio analiza cómo los intereses (altruismo vs. egoísmo) y el marco objetivo (ganancia vs. pérdida) influyen en la intención de pago de compensación de carbono de los turistas en la industria aérea.
Diseño/método
Se emplearon métodos experimentales en dos estudios iniciales para explorar la interacción entre intereses y marco objetivo, y el papel mediador de la responsabilidad moral y la confianza en la aerolínea. Un tercer estudio en un aeropuerto evaluó el efecto moderador de la elevación moral.
Resultados
Los intereses y el marco objetivo influyen conjuntamente en la intención de pago de compensación de carbono. La combinación de altruismo con un marco de ganancia y egoísmo con un marco de pérdida aumenta esta intención. La responsabilidad moral y la confianza en la aerolínea median estos efectos, mientras que la elevación moral modera su impacto.
Originalidad/valor
Este estudio amplía la investigación sobre la compensación de carbono, revelando cómo la interacción entre intereses y marco objetivo afecta la intención de pago, ofreciendo recomendaciones prácticas para la industria aérea.
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Baogang Wen, Hongjun Ren, Pengfei Dang, Xu Hao and Qingkai Han
The oil film thickness provides a key performance indicator of a ball bearing lubrication condition. This paper aims to propose an approach to calculate and measure the oil film…
Abstract
Purpose
The oil film thickness provides a key performance indicator of a ball bearing lubrication condition. This paper aims to propose an approach to calculate and measure the oil film thickness of the bearing.
Design/methodology/approach
On a specially designed test rig, measurement of the capacitance is used to monitor the oil film thickness of ball bearing. A corrected film thickness formula taking account of the influences of non-Newtonian shear thinning and thermal is introduced to predict the oil film thickness of ball bearing. And then the film thickness distribution and the corresponding capacitances are calculated.
Findings
Measurement and calculation of oil film thickness in a ball bearing are carried out under various rotating speeds and external loads. By comparing the calculated capacitances with measured results, it can be concluded that the calculated results obtained by the amended film thickness formula are much closer to the test findings than the classical computed values according to Hamrock–Dowson.
Originality/value
A new corrected film thickness formula is introduced in predicting oil film thickness of ball bearing and verified by the series of experiments according to capacitance method.
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Xiuyun Yang and Qi Han
The purpose of this study is to investigate whether the corporate environmental, social and governance (ESG) performance of enterprise is influenced by the enterprise digital…
Abstract
Purpose
The purpose of this study is to investigate whether the corporate environmental, social and governance (ESG) performance of enterprise is influenced by the enterprise digital transformation. In addition, this study explains how enterprise digital transformation affects ESG performance.
Design/methodology/approach
The sample covers 4,646 nonfinancial companies listed on China’s A-share market from 2009 to 2021. The study adopts the fixed-effects multiple linear regression to perform the data analysis.
Findings
The study finds that enterprise digital transformation has a significant inverted U-shaped impact on ESG performance. Moderate digital transformation can improve enterprise ESG performance, whereas excessive digital transformation will bring new organizational conflicts and increase enterprise costs, which is detrimental to ESG performance. This inverted U-shaped effect is more pronounced in industrial cities, manufacturing industries and enterprises with less financing constraints and executives with financial backgrounds. Enterprise digital transformation mainly affects ESG performance by affecting the level of internal information communication and disclosure, the level of internal control and the principal-agent cost.
Practical implications
The government should take multiple measures to encourage enterprises to choose appropriate digital transformation based on their own production behaviors and development strategies, encourage them to innovate and upgrade their organizational management and development models in conjunction with digital transformation and guide them to use digital technology to improve ESG performance.
Social implications
This study shows that irrational digital transformation cannot effectively improve the ESG performance of enterprises and promote the sustainable development of the country. Enterprises should carry out reasonable digital transformation according to their own development needs and finally improve the green and sustainable development ability of enterprises and promote the sustainable development of society.
Originality/value
This study examines the relationship between enterprise digital transformation and ESG performance. Different from the linear relationship between the two in previous major studies, this study proves the inverse U-shaped relationship between enterprise digital transformation and ESG performance through mathematical theoretical model derivation and empirical test. This study also explores in detail how corporate digital transformation affects ESG performance, as well as discusses heterogeneity at the city, industry and firm levels. It is proposed that enterprises should take into account their own characteristics and carry out reasonable digital transformation according to their development needs.