Peng Cai, Pingjie Zhang, Xiong Xiao, Wenneng Yang, Xiaohan Wu, Lingli Ni and Fei Zheng
The purpose of this paper is to investigate the effect of mullite on the mechanical properties and friction of carbon fiber (CF)-reinforced friction material.
Abstract
Purpose
The purpose of this paper is to investigate the effect of mullite on the mechanical properties and friction of carbon fiber (CF)-reinforced friction material.
Design/methodology/approach
CF-reinforced friction materials with varying content of mullite were fabricated by hot press molding, and then the tribological properties were tested on the MRH-3-type tribometer under ambient conditions with the ring-on-block configuration.
Findings
The experimental results indicated that the addition of mullite increased the density and compressive strength of friction material. However, the flexural strength of friction material decreased by 16% with the addition of 15 Wt.% mullite. The friction coefficient was proportional to the mullite content. Friction material with 12.5 Wt.% mullite showed the highest friction stability under different loads, whereas friction material with 10 Wt.% mullite exhibited the highest friction stability under different sliding speeds.
Originality/value
By boosting the resistance to deformation under load and increasing the specific heat capacity, mullite contributed significantly to the friction stability of the friction material.
Details
Keywords
Peng Cai, Zhongfan Luo, Xuhua Duan and Xinshao Qin
The purpose of this paper is to investigate the effect of reciprocating and unidirectional sliding motions on friction and wear of phenolic resin-based composite.
Abstract
Purpose
The purpose of this paper is to investigate the effect of reciprocating and unidirectional sliding motions on friction and wear of phenolic resin-based composite.
Design/methodology/approach
The phenolic resin-based composite was fabricated by hot press molding, and then the tribological properties were tested on a CSM tribometer with two types of friction motion modes – reciprocating friction and unidirectional friction.
Findings
The results showed that the composite exhibited low friction coefficient in unidirectional test. However, the wear factor recorded under unidirectional sliding condition was 12-16 times higher than the reciprocating friction results. The SEM and optical microscopy test results showed that changing the relative motion mode resulted in different topography of transfer film, which is responsible for the different friction and wear characteristics of the composite under reciprocating and unidirectional friction conditions.
Originality/value
Effect of different friction modes, reciprocating friction and unidirectional friction, on friction characteristics of the composite is sought. Different topography of transfer film formed under reciprocating and unidirectional friction conditions contributed to the different friction characteristics.
Details
Keywords
Peng Cai, Chengpeng Xu, Fei Zheng, Jingfu Song and Gai Zhao
The purpose of this paper is to investigate the effect of lanthana (La2O3) on the mechanical and tribological properties of polyimide (PI).
Abstract
Purpose
The purpose of this paper is to investigate the effect of lanthana (La2O3) on the mechanical and tribological properties of polyimide (PI).
Design/methodology/approach
The mechanical and tribological properties of PI nanocomposites filled with La2O3 were studied by molecular dynamic simulations to explore the deep mechanisms from an atomic or molecular view.
Findings
The results showed that the hardness of the PI matrix increased after La2O3 modification with a decrease of 72.4% nanoindentation depth. Besides, the friction coefficient of PI decreased by 72.2% after filling La2O3, and the shear deformation was largely reduced under the same conditions. The adsorption effect of La2O3 on the PI molecular, which reduced the atomic relative concentration, velocity, interaction with counterpart Fe layer and the temperature rise in the frictional interface, contributed to the improvement of the mechanical and tribological performance.
Originality/value
This study reveals the friction and wear mechanism of PI composites filled with rare earth oxide at the nanoscale.
Details
Keywords
Clinton Cassar and Mario Thomas Vassallo
Undeniably, plastic usage is predominant in our daily lives, featuring in an endless list of items such as bottles, disposables, packaging and fabric. At prima facie, plastic…
Abstract
Undeniably, plastic usage is predominant in our daily lives, featuring in an endless list of items such as bottles, disposables, packaging and fabric. At prima facie, plastic disposal causes irreversible damage to the natural environment, especially oceans. However, it also impacts human health and wellbeing, especially since its toxins or microplastics find themselves in the food chain. Since plastic causes a myriad of negative effects on the natural environment and human health, the urgency to ban it has been addressed by international organizations and the European Union (EU). Being the smallest member state within the EU, Malta presents an insightful case study of how different levels of governance and a plethora of state and non-state actors engage in a game-like interaction. To this effect, this chapter sheds light on the implications of plastic pollution vis-á-vis sustainability and wellbeing, addressed through multi-level governance. The research core revolves around an investigation on the institutional intricacies in addressing the wicked problem of single-use plastic by mapping out the different layers of policy-making mechanisms that are involved, ranging from local to European and international governance, and from governmental to civil society centric strategies. A positivist ontology is activated to underpin the exploratory nature of this study. Through the application of content analysis of selected documentation, the extent of coordination and synergies among the different policy actors across a multi-layered governance platform is put under scrutiny. Quantitative findings are utilized to validate or contradict the original set of hypotheses and to propose a number of policy and governance recommendations that are useful to researchers and practitioners in the fields of public policy, politics, environmental science, public health and wellbeing, as well as insurance and risk management.
Details
Keywords
In family firms, growth is intricately linked not only to strategic business decisions but also to the dynamics of generational involvement and entrepreneurial orientation (EO)…
Abstract
In family firms, growth is intricately linked not only to strategic business decisions but also to the dynamics of generational involvement and entrepreneurial orientation (EO). While previous research has explored the connection between family firm growth and EO, it often overlooks the moderating role that generational involvement could play in this relationship. To address this gap in the literature and investigate its potential impact, this study aims to examine how generational involvement shapes the effects of EO on growth. Based on a quantitative study involving 150 Tunisian family firms and employing a questionnaire-based approach along with structural equation modeling using SPSS 22 and AMOS software, the findings reveal that not all dimensions of EO equally contribute to growth. Specifically, proactiveness, competitive aggressiveness, and autonomy influence growth directly and in the presence of generational involvement as moderators. The effectiveness of these dimensions in driving growth is contingent upon the active and collaborative participation of diverse family generations in the entrepreneurial activities of the family firm. This research pinpoints the importance of family firms that wish to ensure long-term EO when multiple generations are involved. It also reaffirms the importance of these notions within family firms for sustaining long-term EO. Furthermore, this study advocates for additional empirical research on the potential role of generational involvement in establishing professionalization and family governance mechanisms. It seeks to explore their impact on the sustainability of entrepreneurial family firms.
Details
Keywords
Yu Feng, Shaolei Wu, Honglei Nie, Chaochao Peng and Wei Wang
The phenomenon of friction and wear in parallel groove clamps under wind vibration in 10 kV distribution networks represents a significant challenge that can lead to their…
Abstract
Purpose
The phenomenon of friction and wear in parallel groove clamps under wind vibration in 10 kV distribution networks represents a significant challenge that can lead to their failure. This study aims to elucidate the wear mechanism of parallel groove clamps under wind-induced vibration through simulation and experimentation.
Design/methodology/approach
FLUENT software was used to simulate the flow around the conductor and the parallel groove fixture, and the Karman vortex street phenomenon was discussed. The stress fluctuations of each component under breeze vibration conditions were investigated using ANSYS, and fretting experimentations were conducted at varying amplitudes.
Findings
The results demonstrate that the impact of breeze vibration on the internal stress of the parallel groove clamps is considerable. The maximum stress observed on the lower clamping block was found to be up to 300 MPa. As wind speed increased, the maximum vibration frequency was observed to reach 72.6 Hz. Concurrently, as the vibration amplitude increased, the damage in the contact zone of the lower clamping block also increased, with the maximum contact resistance reaching 78.0 µO at a vibration amplitude of 1.2 mm. This was accompanied by a shift in the wear mechanism from adhesive wear to oxidative wear and fatigue wear.
Originality/value
This study presents a comprehensive analysis of the fretting wear phenomenon associated with parallel groove clamps under wind vibration. The findings provide a reference basis for the design and protection of parallel groove clamps.
Details
Keywords
Xin Chen, En Xie, Mike W. Peng and Brian C. Pinkham
The purpose of this paper is to examine an important yet underexplored research question in the literature: What determines the length of contract governing buyer–supplier…
Abstract
Purpose
The purpose of this paper is to examine an important yet underexplored research question in the literature: What determines the length of contract governing buyer–supplier relationships during market transitions? The length of contract is a solid indicator of the comprehensiveness of a contract. By integrating transaction costs economics, the embeddedness perspective and the institution-based view, the paper develops a model that incorporates specific investments and perceived opportunism, strategies to select suppliers and buyer firms’ confidence in the institutional environment. It further posits how buyer firms’ dependence on suppliers moderates these relationships.
Design/methodology/approach
Data were collected nationwide via face-to-face interviews with 328 executives in 164 Chinese firms who shared information pertaining to 774 buyer–supplier contracts. A fine-grained mixed-empirical method was designed to test the proposed hypotheses, to confirm the reliability and to generalize the research findings.
Findings
All the proposed factors significantly influence the length of the contract. Results obtained through a moderated mediating model suggest that buyers with supplier-specific investments and that choose market-based selection relative to a relationship-based tend to perceive more opportunism in buyer–supplier relationships, which will lead to shortening the length of the contract. However, the buyer’s perception of opportunism will decrease when buyers perceive higher levels of confidence in their legal institutions.
Practical implications
The study discusses several practical implications for B2B managers who typically involve in interfirm exchanges as well as for emerging economies’ institutions.
Originality/value
Leveraging theoretical insights from transaction cost economics, the institution-based view and buyer–supplier relationships literature, this empirical study adds unique contributions to B2B research in general and emerging economies’ institutional literature in particular.
Details
Keywords
Ren Hong, Wang Peng, Cai Weiguang, Li Dandan, Du Yongjie, Sun Junqiao and Daniel Abramson
Visitor center plays an important role in the normal operation and sustainable development of scenic spots, especially as a portal image of its management. This paper presents…
Abstract
Visitor center plays an important role in the normal operation and sustainable development of scenic spots, especially as a portal image of its management. This paper presents resilience theory for visitor centers to identify some common issues in designing visitor centers in China scenic spots, including the lack of function, loss of architectural characteristics, and difficultly in adapting to changes in the number of visitors with periodic variations. The framework of resilience theory was set from four dimensions, namely, resilience and match in the composition of ontology function, the extended function, integration of buildings into the surrounding environment, and alternative construction technologies and materials. This theory was explained and analyzed with the application of the theory in practice in combination with the design of Mount Hua visitor center. Results showed that resilience theory yields good application effect.
Details
Keywords
Sheng Peng, Lu-jun Cai, Tian-hua Jiang and Xu Kai
The purpose of this paper is to investigate the explosive performance and explosion damage mechanism of T-beam bridge structure.
Abstract
Purpose
The purpose of this paper is to investigate the explosive performance and explosion damage mechanism of T-beam bridge structure.
Design/methodology/approach
On the basis of the existing specification, two T-beam bridge models were designed and fabricated. Test specimens of different explosive dosage and different blast height were carried out. The mechanical process, failure mode, blast damage model, damage identification mechanism and blast evolution law and quantitative evaluation were taken into account.
Findings
The results revealed that the web plate fracture failure is the key to the unstable failure of the whole T-beam bridge. The explosion failure phenomenon and blast damage evaluation criterion of RC T-beam bridge was divided into five stages: the original cracks stage of concrete material (D = 0 ∼ 0.1), the fractures initiation stage of concrete material (D = 0.1 ∼ 0.3), the stable expansion stage of cracks in concrete material (D = 0.3 ∼ 0.55), the unstable expansion stage of cracks in concrete material (D = 0.55 ∼ 0.8), the explosion fracture of steel bars and the overall instability and damage of the bridge (D = 0.8 ∼ 1.0), which can also be described as basically intact, slight damage, moderate damage, severe damage and collapsed.
Social implications
The research result will provide basis for the antiknock evaluation and damage repair technical specifications of the RC T-beam bridge.
Originality/value
The research results of damage evaluation serve as a basis for damage repair and reinforcement of bridge structures after explosion.
Details
Keywords
Fei Xie and Haijun Wei
Using computer technology to realize ferrographic intelligent fault diagnosis technology is fundamental research to inspect the operation of mechanical equipment. This study aims…
Abstract
Purpose
Using computer technology to realize ferrographic intelligent fault diagnosis technology is fundamental research to inspect the operation of mechanical equipment. This study aims to effectively improve the technology of deep learning technology in the field of ferrographic image recognition.
Design/methodology/approach
This paper proposes a binocular image classification model to solve ferrographic image classification problems.
Findings
This paper creatively proposes a binocular model (BesNet model). The model presents a more extreme situation. On the one hand, the model is almost unable to identify cutting wear particles. On the other hand, the model can achieve 100% accuracy in identifying Chunky and Nonferrous wear particles. The BesNet model is a bionic model of the human eye, and the used training image is a specially processed parallax image. After combining the MCECNN model, it is changed to BMECNN model, and its classification accuracy has reached the highest level in the industry.
Originality/value
The work presented in this thesis is original, except as acknowledged in the text. The material has not been submitted, either in whole or in part, for a degree at this or any other university. The BesNet model developed in this article is a brand new system for ferrographic image recognition. The BesNet model adopts a method of imitating the eyes to view ferrography images, and its image processing method is also unique. After combining the MCECNN model, it is changed to BMECNN model, and its classification accuracy has reached the highest level in the industry.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0150/