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Article
Publication date: 28 August 2023

ShuYu Guo, Lin Fan, Yan He, BoHan Geng, MingQi Chen and Yuhang Wang

This study aims to investigate the effect of microtextured tools on the geometric morphology of serrated chips, and further improve the cutting performance of polycrystalline…

Abstract

Purpose

This study aims to investigate the effect of microtextured tools on the geometric morphology of serrated chips, and further improve the cutting performance of polycrystalline cubic boron nitride (PCBN) tool and extend the tool life and the surface quality of the machined surface.

Design/methodology/approach

A three-dimensional finite element cutting model of hardened steel AISI D2 with microtextured PCBN tools were established using the finite element software Abaqus, and cutting tests were carried out. Furthermore, the stress distribution in the primary deformation zone was investigated based on the triaxiality of stress, and the influence of microtexture on the geometric morphology of serrated chips and crack development was researched.

Findings

The results show that compared with nontexture tools, elliptical pits and wavy grooves microtexture tools have lower serrated degree Gs, higher serrated frequency f per unit length and more miniature serrated step Pc. The serrated phenomenon is intensified because the tensile stress zone of chips generated by nontextured tools is longer than that of elliptic pits and wavy grooves microtexture tools. Simultaneously, the maximum value of triaxiality in the tensile stress zone achieved by nontexture tools is larger than that of the two microtexture tools, and chips obtained by nontextured tools are more susceptible to propagation fractures.

Originality/value

This paper mainly studies the effect of microtexture on chip microgeometry, which is relatively little studied at present. At the same time, this paper has a certain engineering significance for PCBN tool turning hardening steel.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0149/

Details

Industrial Lubrication and Tribology, vol. 75 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 22 August 2023

Feng Shuang, Yang Du, Shaodong Li and Mingqi Chen

This study aims to introduce a multi-configuration, three-finger dexterous hand with integrated high-dimensional sensors and provides an analysis of its design, modeling and…

Abstract

Purpose

This study aims to introduce a multi-configuration, three-finger dexterous hand with integrated high-dimensional sensors and provides an analysis of its design, modeling and kinematics.

Design/methodology/approach

A mechanical design scheme of the three-finger dexterous hand with a reconfigurable palm is proposed based on the existing research on dexterous hands. The reconfigurable palm design enables the dexterous hand to achieve four grasping modes to adapt to multiple grasping tasks. To further enhance perception, two six-axis force and torque sensors are integrated into each finger. The forward and inverse kinematics equations of the dexterous hand are derived using the D-H method for kinematics modeling, thus providing a theoretical model for index analysis. The performance is evaluated using three widely applied indicators: workspace, interactivity of fingers and manipulability.

Findings

The results of kinematics analysis show that the proposed hand has excellent dexterity. Additionally, three different experiments are conducted based on the proposed hand. The performance of the dexterous hand is also verified by fingertip force, motion accuracy test, grasping and in-hand manipulation experiments based on Feix taxonomy. The results show that the dexterous hand has good grasping ability, reproducing 82% of the natural movement of the human hand in daily grasping activities and achieving in-hand manipulations such as translation and rotation.

Originality/value

A novel three-finger dexterous hand with multi-configuration and integrated high-dimensional sensors is proposed. It performs better than the previously designed dexterous hand in actual experiments and kinematic performance analysis.

Details

Industrial Robot: the international journal of robotics research and application, vol. 50 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 14 June 2011

Weihui Dai, Mingqi Chen and Nan Ye

The purpose of this paper is to define and analyze the innovation system of China's software industry in order to build its innovation capability.

770

Abstract

Purpose

The purpose of this paper is to define and analyze the innovation system of China's software industry in order to build its innovation capability.

Design/methodology/approach

From a complex adaptive systems (CAS) perspective, the authors researched the constitution and operating mechanism of China's software industry innovation system. By using methods and theories of CAS theory, the innovation problems of the software industry in China were analyzed and valuable suggestions put forth for its future development.

Findings

Innovation system is one kind of complex systems and it has the characteristics of CAS.

Research limitations/implications

Quantitative analysis of the software industry innovation system should be emphasized in the next stage of research.

Practical implications

The paper provides a new perspective and useful advice for technology policymakers.

Originality/value

The paper applies CAS theory to the area of social management and provides a new approach to study industrial innovation systems.

Details

Kybernetes, vol. 40 no. 5/6
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 11 August 2020

Mingqi Gu, Wei Zhang, Shang Hao, Xiaochen Liu, Zichao Zhang and Fenjuan Shao

This study aims to explore the infrared imaging effect of fabrics coated with phase change material microcapsules (PCM-MCs), which are prepared by the initiation of ultraviolet…

Abstract

Purpose

This study aims to explore the infrared imaging effect of fabrics coated with phase change material microcapsules (PCM-MCs), which are prepared by the initiation of ultraviolet (UV) light.

Design/methodology/approach

PCM-MCs were prepared by UV polymerization using paraffin (PA) as core material, polymethyl methacrylate as wall material and ferric chloride as photoinitiator. The effects of emulsifier dosage and emulsification temperature on the properties of PA emulsion were investigated. Scanning electron microscopy, particle size analysis, infrared spectroscopy, differential scanning calorimetry and infrared imaging test were used to characterize the properties of microcapsules.

Findings

The PCM-MCs with good morphology and particle size were prepared with 25 cm of the distance between light source and the liquid. The average particle size was 1.066 µm and the latent heat of phase transition was 19.96 J/g. After 100 accelerated thermal cycles, the latent heat only decreased by 1.8%. It had good heat storage stability and thermal stability. The fabric coated by the microcapsules exhibited a variable temperature hysteresis effect when placed in the sun, and presented a color close to the infrared images of the human palm under the external environment temperature close to the human body temperature.

Research limitations/implications

The PCM-MCs prepared based on UV light initiation showed good thermal properties and its coated fabrics had an infrared decoy effect below the temperature of the human body.

Practical implications

This study explored the application of microcapsules in textiles.

Originality/value

The microcapsules had a certain application potential in infrared decoy effect.

Details

Pigment & Resin Technology, vol. 50 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 14 April 2014

Yujia He

Rare earths are essential materials for many high-tech industries critical to both economic development and national defense. China, the world's dominant supplier of rare earths…

Abstract

Purpose

Rare earths are essential materials for many high-tech industries critical to both economic development and national defense. China, the world's dominant supplier of rare earths, has recently been imposing stricter controls over its production and export. The purpose of this paper is to examine the domestic roots of the changes in China's rare earth industry production and exports in its three-decade rise to the current global monopoly.

Design/methodology/approach

This paper adopts the historical institutionalism approach to analyze the trajectory of industry and trade development. The author analyzes data collected from government whitepapers and reputed scholarly and news sources.

Findings

This paper argues that the Chinese rare earth industry has gone through three periods of development, in which the state attempted to control the market and industry through reformulating rules and institutions to achieve state goals. Domestic state institutions, combined with macroeconomic environment and state governance strategy shaped the three-decade experience of rare earth industry and trade development in China.

Originality/value

This paper builds on existing findings about Chinese state regulations to provide a novel analytical framework to analyze the role of the state in industry and trade development in the rare earth industry. The focus on a single strategic industry seldom studied in the current literature also provides ample empirical value to further scholarly understanding about this industry.

Details

International Journal of Emerging Markets, vol. 9 no. 2
Type: Research Article
ISSN: 1746-8809

Keywords

Article
Publication date: 11 October 2011

Mirela Galic, Pavao Marovic and Zeljana Nikolic

The main aim of this paper is to present a three‐dimensional numerical material model for concrete which combines plasticity with a classical orthotropic smeared crack…

1161

Abstract

Purpose

The main aim of this paper is to present a three‐dimensional numerical material model for concrete which combines plasticity with a classical orthotropic smeared crack formulation. A further aim is to raise a discussion leading to the creation of a comprehensive computer programme for the analyses of reinforced and prestressed concrete structures.

Design/methodology/approach

A new numerical material model for concrete is developed and main theoretical explanations are given to aid in understanding the algorithm. The model is based on Mohr‐Coulomb criterion for dominant compression and Rankine criterion for dominant tension influences. A multi‐surface presentation of the model is implemented which permits the rapid convergence of the mathematical procedure. The model includes associated and non‐associated flow rules, strain hardening and softening where the development of the plastic strain was described by the function of cohesion.

Findings

Provides information about developing a new numerical material model for concrete.

Practical implications

The model is implemented into the computer programme PRECON3D for the three‐dimensional nonlinear analysis of the reinforced and prestressed concrete structures.

Originality/value

In this model, the very complex behaviour of concrete is defined by elementary material parameters which can be obtained by a standard uniaxial test. The presented model enables a very detailed and precise analysis of reinforced and prestressed concrete structures until crushing with a high accuracy, so that the expensive experimental tests can be reduced. The paper could be very valuable to researchers in this field as a benchmark for their analyses.

Details

Engineering Computations, vol. 28 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Open Access
Article
Publication date: 14 October 2021

Sakhri Aicha and Ahcene Merad

This study describes the applicability of the a priori estimate method on a nonlocal nonlinear fractional differential equation for which the weak solution's existence and…

Abstract

Purpose

This study describes the applicability of the a priori estimate method on a nonlocal nonlinear fractional differential equation for which the weak solution's existence and uniqueness are proved. The authors divide the proof into two sections for the linear associated problem; the authors derive the a priori bound and demonstrate the operator range density that is generated. The authors solve the nonlinear problem by introducing an iterative process depending on the preceding results.

Design/methodology/approach

The functional analysis method is the a priori estimate method or energy inequality method.

Findings

The results show the efficiency of a priori estimate method in the case of time-fractional order differential equations with nonlocal conditions. Our results also illustrate the existence and uniqueness of the continuous dependence of solutions on fractional order differential equations with nonlocal conditions.

Research limitations/implications

The authors’ work can be considered a contribution to the development of the functional analysis method that is used to prove well-positioned problems with fractional order.

Originality/value

The authors confirm that this work is original and has not been published elsewhere, nor is it currently under consideration for publication elsewhere.

Details

Arab Journal of Mathematical Sciences, vol. 29 no. 2
Type: Research Article
ISSN: 1319-5166

Keywords

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