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Article
Publication date: 5 February 2018

Zhiyong Wang, Jing Gu, Cheng Hou and Ming Song

The purpose of this paper is to propose the interaction integral method combing with a XFEM-based local mesh replacement method to evaluate both the stress intensity factors…

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Abstract

Purpose

The purpose of this paper is to propose the interaction integral method combing with a XFEM-based local mesh replacement method to evaluate both the stress intensity factors (SIFs) and T-stress at the crack tip near a circular inclusion.

Design/methodology/approach

Special attention is pay to the effect of T-stress on crack initiation angle in 2D composite medium. The generalized maximum tangential stress criterion is employed during the simulation which simultaneously involves the effects of the mixed-mode SIFs, the T-stress and a physical length scale rc (the size of the fracture process zone).

Findings

It is shown that T-stress could affect the crack initiation angle significantly for mixed-mode conditions. Varies types of material mismatch are also considered and their influences on T-stress are given quantitatively.

Originality/value

The proposed numerical method allows a considerable flexibility for such problems and provides a basic framework for quasi-static crack growth in materials containing complex interfaces.

Details

Multidiscipline Modeling in Materials and Structures, vol. 14 no. 2
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 15 September 2022

Zhiyong Wang, Yuankai Zhou and Xue Zuo

The purpose of this paper is to study the tribological effect of zinc borate ultrafine powder (ZBUP) oil additive on the running-in quality.

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Abstract

Purpose

The purpose of this paper is to study the tribological effect of zinc borate ultrafine powder (ZBUP) oil additive on the running-in quality.

Design/methodology/approach

The running-in quality was assessed by friction coefficient and surface topography. Fractal parameters including fractal dimension, the width of multifractal, the multifractal difference, multifractal parameters, phase trajectory and correlation dimension were used to extract the nonlinear characteristics of surface topography and friction coefficient.

Findings

When the ZBUP additive was added, the convergence degree of the phase trajectory and the stability of the running in were higher than that of base oil. It indicates that the ZBUP additive can improve the running-in quality of sliding bearing. Besides, the ZBUP additive can shorten the running-in time. A boundary protective film, which has good friction-reducing and anti-wear effects, was generated on the surface when the ZBUP additive was added.

Originality/value

The results have a great significance to improve the running-in quality and prolong the service life of the sliding bearing.

Details

Industrial Lubrication and Tribology, vol. 74 no. 10
Type: Research Article
ISSN: 0036-8792

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Publication date: 23 October 2020

Zhiyong Yang, Ying Wang and Jiyoung Hwang

Generation Z makes up 20% of China’s population, and accounts for the highest share of household spend at 13% (vs. 3% for the United Kingdom and 4% for the United States). To…

Abstract

Generation Z makes up 20% of China’s population, and accounts for the highest share of household spend at 13% (vs. 3% for the United Kingdom and 4% for the United States). To advance marketers’ understanding about this group of consumers and capitalise on China’s booming market, this chapter uses rich statistics and information to show that China’s Generation Z has distinct behaviour patterns, which can be attributed to the unique background in which they grew up: (1) rigidity of social stratification, (2) abundance of materialism, (3) digital era, (4) limited (vs. extended) family, and (5) heavy schoolwork. Growing up in such a background, Generation Z’s lifestyle and consumption-related attitudes and behaviour are distinct from their predecessors. The chapter presents specific actions that marketers can take when targeting this distinct group of consumers in China, along with useful guidelines to HR managers for hiring them.

Details

The New Generation Z in Asia: Dynamics, Differences, Digitalisation
Type: Book
ISBN: 978-1-80043-221-5

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Article
Publication date: 23 October 2015

Shu Yi, Lin Xiao, Yong Zhang, Dujuan Duan and Maksim G. Blokhin

This paper describes the organic geochemical characteristics and their roles on barium enrichment in the No. 2 Coal from Huanglong Jurassic Coalfield, China. A total of 18 bench…

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Abstract

This paper describes the organic geochemical characteristics and their roles on barium enrichment in the No. 2 Coal from Huanglong Jurassic Coalfield, China. A total of 18 bench samples were taken from Huangling Mine 2. The average content of barium (3701 mg/kg) was about 23 times higher than that of common world coals. Terrestrial higher plants were the main coal-forming parent material. Relying on the parameters of OEP, Pr/Ph and so on, there is little correlation between organic geochemical characteristics and barium enrichment. Therefore, organic material has little influence on the process of coal-forming and the enrichment of barium.

Details

World Journal of Engineering, vol. 12 no. 5
Type: Research Article
ISSN: 1708-5284

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Available. Content available
Book part
Publication date: 23 October 2020

Abstract

Details

The New Generation Z in Asia: Dynamics, Differences, Digitalisation
Type: Book
ISBN: 978-1-80043-221-5

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Article
Publication date: 20 April 2012

Hur‐Li Lee

This study aims to understand the epistemic foundation of the classification applied in the first Chinese library catalogue, the Seven Epitomes (Qilue).

1050

Abstract

Purpose

This study aims to understand the epistemic foundation of the classification applied in the first Chinese library catalogue, the Seven Epitomes (Qilue).

Design/methodology/approach

Originating from a theoretical stance that situates knowledge organization in its social context, the study applies a multifaceted framework pertaining to five categories of textual data: the Seven Epitomes; biographical information about the classificationist Liu Xin; and the relevant intellectual, political, and technological history.

Findings

The study discovers seven principles contributing to the epistemic foundation of the catalogue's classification: the Han imperial library collection imposed as the literary warrant; government functions considered for structuring texts; classicist morality determining the main classificatory structure; knowledge perceived and organized as a unity; objects, rather than subjects, of concern affecting categories at the main class level; correlative thinking connecting all text categories to a supreme knowledge embodied by the Six Classics; and classicist moral values resulting in both vertical and horizontal hierarchies among categories as well as texts.

Research limitations/implications

A major limitation of the study is its focus on the main classes, with limited attention to subclasses. Future research can extend the analysis to examine subclasses of the same scheme. Findings from these studies may lead to a comparison between the epistemic approach in the target classification and the analytic one common in today's bibliographic classification.

Originality/value

The study is the first to examine in depth the epistemic foundation of traditional Chinese bibliographic classification, anchoring the classification in its appropriate social and historical context.

Details

Journal of Documentation, vol. 68 no. 3
Type: Research Article
ISSN: 0022-0418

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Article
Publication date: 13 May 2014

Jun Wu, Yingli Pan and Qi Zhu

– The purpose of this paper is to identify the determinants for currency internationalization and forecast the potential of RMB as an international reserve currency.

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Abstract

Purpose

The purpose of this paper is to identify the determinants for currency internationalization and forecast the potential of RMB as an international reserve currency.

Design/methodology/approach

This paper performs linear or non-linear regressions of the shares of eight major international reserve currencies as the reserve assets in global central banks on the macro economic and financial variables of their corresponding countries to identify the determinants for their international positions, and conducts an “counter-factual simulation” for the potential of RMB as an international reserve currency.

Findings

This paper finds that the economic size and the “network externalities” are the most important determinants for the international status of a reserve currency; that exchange rate volatility has negative impacts; the conditions for the RMB internationalization are basically available. The simulation for the potential of RMB as an international reserve currency reveals that the international role of RMB could surpass that of the Japanese Yen and the British Pound, and get close to Euro in the coming 15 years. Based on the empirical evidence, this paper suggests a promoting strategy for RMB internationalization.

Research limitations/implications

This paper has not taken the influence of economic systemic and political factors on the process of RMB internationalization into account.

Practical implications

RMB internationalization promotion should follow the strategy of “stably create RMB international demand in the initial period and dramatically release the RMB overseas supply in the latter period” in the coming 15 years.

Originality/value

The conclusions and policy implications are from the results of the empirical analysis on the 45-year historical experience on the eight main international currencies.

Details

China Finance Review International, vol. 4 no. 2
Type: Research Article
ISSN: 2044-1398

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Article
Publication date: 1 January 2024

Shi Chen, Zhiyong Han, Qiang Zeng, Bing Wang, Liming Wang, Liuyang Guo and Yimin Shao

Hydro-viscous drive (HVD) clutches are widely used in equipment requiring soft start, such as fans and pumps, to transmit torque and adjust speed by changing the gap distance…

157

Abstract

Purpose

Hydro-viscous drive (HVD) clutches are widely used in equipment requiring soft start, such as fans and pumps, to transmit torque and adjust speed by changing the gap distance between friction pairs. This paper aims to propose a novel two-parameter evaluation method for HVD during the mixed lubrication stage. The objective is to develop an effective model that establishes the relationship between these parameters and the actual surface topography.

Design/methodology/approach

In the presented methods, the fractal features of the real manufacturing surface are calculated based on the power spectrum function by the ultra-depth three-dimensional microscope. After that, the hybrid friction model of the friction plate is established based on mixed elasto-hydrodynamic lubrication theory, boundary friction model and fractal theory. Then the torque and load bearing characteristics of the clutch are obtained, and the influences of the surface fractal features are investigated and discussed. Finally, the Weierstrass–Mandelbrot function is adopted for the surface topography characterization and evaluation.

Findings

The results indicate that the proposed method exhibits good accuracy, while the speed difference between the friction pair exceeds 2,500 rpm. It is concluded that this paper proposed a way to evaluate the torque and loading capacity of HVD considering the real manufacturing surface topography and is helpful for surface optimization.

Originality/value

The originality and value of this study lie in its development of a novel torque and load bearing capacity evaluation method for HVD in mixed lubrication stage, considering manufacturing surface topography and describing the real manufacturing surface.

Details

Industrial Lubrication and Tribology, vol. 76 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 10 July 2017

Chaoran Liu, Yufeng Su, Jinzhao Yue, Junjie Wang, Weiwei Xia, Dongxue Li, Wen Wang, Pan Wang and Zhiyong Duan

A self-adaptive piston is designed for the compressional gas cushion press nanoimprint lithography system. It avoids the lube pollution and high wear of traditional piston.

89

Abstract

Purpose

A self-adaptive piston is designed for the compressional gas cushion press nanoimprint lithography system. It avoids the lube pollution and high wear of traditional piston.

Design/methodology/approach

The self-adaptive piston device consists of symmetrical piston bodies, piston rings and other parts. The two piston bodies are linked by a ball-screw. The locking nut adjusts the distance between two piston bodies to avoid the piston rings from being stuck. The piston rings are placed between two piston bodies.

Findings

The simulation results based on COMSOL indicate that cylinder vibration caused by self-adaptive piston is 15.9 times smaller than the one caused by a traditional piston.

Originality/value

The self-adaptive piston is superior to the traditional piston in decreasing cylinder vibration.

Details

Industrial Lubrication and Tribology, vol. 69 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 15 October 2024

Mengli Wu, Yilong Xu, Xuhao Wang, Hao Liu, Guanhao Li, Chengfa Wang, Yiran Cao and Zhiyong Guo

This paper aims to present the mechanical design and kinematics of a novel rigid-flexible coupling hybrid robot to develop a promising aeroengine blades in situ repair technology.

96

Abstract

Purpose

This paper aims to present the mechanical design and kinematics of a novel rigid-flexible coupling hybrid robot to develop a promising aeroengine blades in situ repair technology.

Design/methodology/approach

According to requirements analysis, a novel rigid-flexible coupling hybrid robot is proposed by combining a three degrees of freedom (DOF) parallel mechanism with a flexible continuum section. Then the kinematics models of both parallel mechanism and flexible continuum section are derived respectively. Finally, based on equivalent joint method, a two-step numerical iterative inverse kinematics algorithm is proposed for the whole robot: (1) the flexible continuum section is equivalently transformed to a 2-DOF spherical joint, thus the approximate analytical inverse kinematic solution can be obtained; (2) the accurate solution is derived by an iterative derivation of both parallel mechanism and flexible continuum section.

Findings

To verify structure scheme and the proposed kinematics modeling method, numerical simulations and prototype experiments are implemented. The results show that the proposed kinematics algorithm has sufficient accuracy and computational efficiency in the whole available workspace, that is end-effector position error and orientation error are less than 0.2 mm and 0.01° respectively, and computation time is less than 0.22s.

Originality/value

A novel rigid-flexible coupling hybrid robot for aeroengine blades in situ repair is designed. A two-step numerical iterative inverse kinematics algorithm is proposed for this unique hybrid robots, which has good accuracy and computational efficiency.

Details

Engineering Computations, vol. 41 no. 10
Type: Research Article
ISSN: 0264-4401

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