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Article
Publication date: 1 February 2002

H. Zhan and W. Zhao

Turbine blisks designed for advanced liquid rocket engine turbopumps are usually of a timed structure with twisted blades, and they can be machined effectively with the electrical…

597

Abstract

Turbine blisks designed for advanced liquid rocket engine turbopumps are usually of a timed structure with twisted blades, and they can be machined effectively with the electrical discharge machining (EDM) process. After the machining specifications have been designated, the EDM process of a turbopump turbine blisk is discussed, in which the kernel problems are the design of the electrode and the searching of an interference free path to feed the electrode to machine the blisk.

Details

Aircraft Engineering and Aerospace Technology, vol. 74 no. 1
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 June 2000

H. Zhan, W. Zhao and G. Wang

Various techniques for manufacturing integrally bladed turbine disks (turbine blisks) are described, followed by a discussion of the development trend of turbine blisk…

2664

Abstract

Various techniques for manufacturing integrally bladed turbine disks (turbine blisks) are described, followed by a discussion of the development trend of turbine blisk manufacture. Analysis shows that powder metallurgy near‐net‐shape hot isostatic pressing will be the focus of future research for turbine blisk blanking, while electrical discharge machining still will be the most competitive technology for turbine blisk finishing.

Details

Aircraft Engineering and Aerospace Technology, vol. 72 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 24 October 2023

Quan-Pu Liu, Jia Kang, Long-Xu Tan, Si-Yu Wang, Otto Bruhns and Heng Xiao

This paper aims to present a direct analysis to demonstrate why markedly different tensile and compressive behaviors of concretes could not be simulated with the Drucker–Prager…

60

Abstract

Purpose

This paper aims to present a direct analysis to demonstrate why markedly different tensile and compressive behaviors of concretes could not be simulated with the Drucker–Prager yield criterion.

Design/methodology/approach

This study proposed an extended form of the latter for establishing a new elastoplasticity model with evolving yield strengths.

Findings

Explicit closed-form solutions to non-symmetric tensile and compressive responses of uniaxial specimens at finite strain are for the first time obtained from hardening to softening.

Originality/value

With such exact solutions, the yield strengths in tension and compression can be explicitly prescribed by uniaxial tensile and compressive stress-strain functions. Then, the latter two are further provided in explicit forms toward accurately simulating tensile and compressive behaviors. Numerical examples are supplied for meso-scale heterogeneous concrete (MSHC) and high-performance concrete (HPC), etc. Model predictions are in good agreement with test data.

Details

Multidiscipline Modeling in Materials and Structures, vol. 19 no. 6
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 5 June 2023

Zengkun Zhang, Dongru Li, Jianjun Wu, Muzamil Muhammad and Yang Li

When bending a large diameter thin-walled tube, the thickn ess of outer side wall will reduce greatly, which leads to a decrease of structural strength of the tube. To solve this…

79

Abstract

Purpose

When bending a large diameter thin-walled tube, the thickn ess of outer side wall will reduce greatly, which leads to a decrease of structural strength of the tube. To solve this problem, this paper investigated the deformation principles of an eccentric tube in the rotary draw bending process, trying to find a way to reduce the wall thickness difference between inner and outer diameters.

Design/methodology/approach

An finite element model is established for analyzing the deformation of an eccentric tube in rotary draw bending process. The wall thickness distribution of the formed pipe was analyzed along the axis and diameter, respectively.

Findings

It is found that there exists an optimal eccentricity between the inner and outer circle center of the tube cross-section. If the eccentricity of the tube is chosen properly, it is possible to get a bent tube with equal thickness of inner and outer side walls. In addition, it is also found the optimal eccentricity on the cross-section can be influenced by bending radius, wall thickness, diameter and bending angle. The optimal eccentricity increases greatly with the decreasing of bending radius, the increase of outer diameter and the increase of wall thickness. The influence of bending angle on the optimal eccentricity can be divided into two situations. When the bending angle is small, the optimal eccentricity increases with the increase of bending angle. When the bending angle exceeds a certain value, the pipe enters a stable forming state. The optimal eccentricity of the stable forming region does not change with the bending angle.

Originality/value

Such a research is beneficial for reducing the thickness difference between inner and outer side walls in the rotary draw bending process.

Details

Engineering Computations, vol. 40 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 18 March 2021

Junliang Du, Sifeng Liu and Yong Liu

The purpose of this paper is to advance a novel grey variable dual precision rough set model for grey concept.

236

Abstract

Purpose

The purpose of this paper is to advance a novel grey variable dual precision rough set model for grey concept.

Design/methodology/approach

To obtain the approximation of a grey object, the authors first define the concepts of grey rough membership degree and grey degree of approximation on the basic thinking logic of variable precision rough set. Based on grey rough membership degree and grey degree of approximation, the authors proposed a grey variable dual precision rough set model. It uses a clear knowledge concept to approximate a grey concept, and the output result is also a clear concept.

Findings

The result demonstrates that the proposed model may be closer to the actual decision-making situation, can effectively improve the rationality and scientificity of the approximation and reduce the risk of decision-making. It can effectively achieve the whitenization of grey objects. The model can be degenerated to traditional variable precision rough fuzzy set model, variable precision rough set model and classic Pawlak rough set, when some specific conditions are met.

Practical implications

The method exposed in the paper can be used to solve multi-criteria decision problems with grey decision objects and provide a decision rule. It can also help us better realize knowledge discovery and attribute reduction. It can effectively achieve the whitenization of grey object.

Originality/value

This method proposed in this paper implements a rough approximation of grey decision object and obtains low-risk probabilistic decision rule. It can effectively achieve a certain degree of whitenization of some grey objects.

Details

Grey Systems: Theory and Application, vol. 12 no. 1
Type: Research Article
ISSN: 2043-9377

Keywords

Available. Open Access. Open Access
Article
Publication date: 4 January 2024

Ahmed A. Khalifa and Mariam A. Ibrahim

The study aims to evaluate PubMed publications on ChatGPT or artificial intelligence (AI) involvement in scientific or medical writing and investigate whether ChatGPT or AI was…

2345

Abstract

Purpose

The study aims to evaluate PubMed publications on ChatGPT or artificial intelligence (AI) involvement in scientific or medical writing and investigate whether ChatGPT or AI was used to create these articles or listed as authors.

Design/methodology/approach

This scoping review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. A PubMed database search was performed for articles published between January 1 and November 29, 2023, using appropriate search terms; both authors performed screening and selection independently.

Findings

From the initial search results of 127 articles, 41 were eligible for final analysis. Articles were published in 34 journals. Editorials were the most common article type, with 15 (36.6%) articles. Authors originated from 27 countries, and authors from the USA contributed the most, with 14 (34.1%) articles. The most discussed topic was AI tools and writing capabilities in 19 (46.3%) articles. AI or ChatGPT was involved in manuscript preparation in 31 (75.6%) articles. None of the articles listed AI or ChatGPT as an author, and in 19 (46.3%) articles, the authors acknowledged utilizing AI or ChatGPT.

Practical implications

Researchers worldwide are concerned with AI or ChatGPT involvement in scientific research, specifically the writing process. The authors believe that precise and mature regulations will be developed soon by journals, publishers and editors, which will pave the way for the best usage of these tools.

Originality/value

This scoping review expressed data published on using AI or ChatGPT in various scientific research and writing aspects, besides alluding to the advantages, disadvantages and implications of their usage.

Details

Arab Gulf Journal of Scientific Research, vol. 42 no. 4
Type: Research Article
ISSN: 1985-9899

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Article
Publication date: 10 July 2023

Surabhi Singh, Shiwangi Singh, Alex Koohang, Anuj Sharma and Sanjay Dhir

The primary aim of this study is to detail the use of soft computing techniques in business and management research. Its objectives are as follows: to conduct a comprehensive…

402

Abstract

Purpose

The primary aim of this study is to detail the use of soft computing techniques in business and management research. Its objectives are as follows: to conduct a comprehensive scientometric analysis of publications in the field of soft computing, to explore the evolution of keywords, to identify key research themes and latent topics and to map the intellectual structure of soft computing in the business literature.

Design/methodology/approach

This research offers a comprehensive overview of the field by synthesising 43 years (1980–2022) of soft computing research from the Scopus database. It employs descriptive analysis, topic modelling (TM) and scientometric analysis.

Findings

This study's co-citation analysis identifies three primary categories of research in the field: the components, the techniques and the benefits of soft computing. Additionally, this study identifies 16 key study themes in the soft computing literature using TM, including decision-making under uncertainty, multi-criteria decision-making (MCDM), the application of deep learning in object detection and fault diagnosis, circular economy and sustainable development and a few others.

Practical implications

This analysis offers a valuable understanding of soft computing for researchers and industry experts and highlights potential areas for future research.

Originality/value

This study uses scientific mapping and performance indicators to analyse a large corpus of 4,512 articles in the field of soft computing. It makes significant contributions to the intellectual and conceptual framework of soft computing research by providing a comprehensive overview of the literature on soft computing literature covering a period of four decades and identifying significant trends and topics to direct future research.

Details

Industrial Management & Data Systems, vol. 123 no. 8
Type: Research Article
ISSN: 0263-5577

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Book part
Publication date: 2 June 2015

Jaclyn Koopmann, Mo Wang, Yihao Liu and Yifan Song

In this chapter, we summarize and build on the current state of the customer mistreatment literature in an effort to further future research on this topic. First, we detail the…

Abstract

In this chapter, we summarize and build on the current state of the customer mistreatment literature in an effort to further future research on this topic. First, we detail the four primary conceptualizations of customer mistreatment. Second, we present a multilevel model of customer mistreatment, which distinguishes between the unfolding processes at the individual employee level and the service encounter level. In particular, we consider the antecedents and outcomes unique to each level of analysis as well as mediators and moderators. Finally, we discuss important methodological concerns and recommendations for future research.

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Article
Publication date: 16 May 2022

Heng Xiao, Zi-Tao Li, Lin Zhan and Si-Yu Wang

The purpose of this study is to show how gradual strength degradation of metal beams under cyclic bending up to fatigue failure is simulated based on a new elastoplasticity model…

89

Abstract

Purpose

The purpose of this study is to show how gradual strength degradation of metal beams under cyclic bending up to fatigue failure is simulated based on a new elastoplasticity model free of any yield criterion.

Design/methodology/approach

A new approach is proposed toward accurately and explicitly prescribing evolution of non-uniform stress distribution on beam cross-section under cyclic bending and, as such, gradual degradation of the bending strength can be directly determined.

Findings

Explicit results for the bending response in a whole cyclic process up to fatigue failure are obtained and the fatigue characteristic curve is for the first time simulated directly between the curvature amplitude and the cycle number to failure.

Originality/value

First, explicit and accurate determination of the non-uniform stress distribution on beam cross-section is achieved with asymptotic softening effects. Second, degradation of the bending strength can be directly deduced cycle by cycle. Finally, the relationship between the bending moment and the curvature is calculated using new and efficient numerical algorithms, thus bypassing usual time-consuming calculations with finite element procedures. Numerical results are presented and in good agreement with experimental data.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 3
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 21 May 2024

Gan Zhan, Zhihua Chen, Zhenyu Zhang, Jigang Zhan, Wentao Yu and Jiehao Li

This study aims to address the issue of random movement and non coordination between docking mechanisms and locking mechanisms, and proposes a comprehensive dynamic docking…

106

Abstract

Purpose

This study aims to address the issue of random movement and non coordination between docking mechanisms and locking mechanisms, and proposes a comprehensive dynamic docking control architecture that integrates perception, planning, and motion control.

Design/methodology/approach

Firstly, the proposed dynamic docking control architecture uses laser sensors and a charge-coupled device camera to perceive the pose of the target. The sensor data are mapped to a high-dimensional potential field space and fused to reduce interference caused by detection noise. Next, a new potential function based on multi-dimensional space is developed for docking path planning, which enables the docking mechanism based on Stewart platform to rapidly converge to the target axis of the locking mechanism, which improves the adaptability and terminal docking accuracy of the docking state. Finally, to achieve precise tracking and flexible docking in the final stage, the system combines a self-impedance controller and an impedance control algorithm based on the planned trajectory.

Findings

Extensive simulations and experiments have been conducted to validate the effectiveness of the dynamic docking system and its control architecture. The results indicate that even if the target moves randomly, the system can successfully achieve accurate, stable and flexible dynamic docking.

Originality/value

This research can provide technical guidance and reference for docking task of unmanned vehicles under the ground conditions. It can also provide ideas for space docking missions, such as space simulator docking.

Details

Industrial Robot: the international journal of robotics research and application, vol. 51 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

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