Ebrahim Vahabli and Sadegh Rahmati
To improve the quality of the additive manufacturing (AM) products, it is necessary to estimate surface roughness distribution in advance. Although surface roughness estimation…
Abstract
Purpose
To improve the quality of the additive manufacturing (AM) products, it is necessary to estimate surface roughness distribution in advance. Although surface roughness estimation has been previously studied, factors leading to the creation of a rough surface and a comprehensive test for model validation have not been adequately investigated. Therefore, this paper aims to establish a robust model using empirical data based on optimized artificial neural networks (ANNs) to estimate the surface roughness distribution in fused deposition modelling parts. Accordingly, process parameters such as time, cost and quality should be optimized in the process planning stage.
Design/methodology/approach
Process parameters were selected via a literature review of surface roughness estimation modelling by analytical and empirical methods, and then a specific test part was fabricated to provide a complete evaluation of the proposed model. The ANN structure was optimized by trial and error method and evolutionary algorithms. A novel methodology based on the combination of the intelligent algorithms including the ANN, linked to the particle swarm optimization (PSO) and imperialist competitive algorithm (ICA), was developed. The PSOICA algorithm was implemented to increase the capability of the ANN to perform much faster and converge more precisely to favorable results. The performances of the ANN models were compared to the most well-known analytical models at build angle intervals of equal size. The most effective process variable was found by sensitivity analysis. The validity of proposed model was studied comprehensively where different truncheon parts and medical case studies including molar tooth, skull, femur and a custom-made hip stem were built.
Findings
This paper presents several improvements in surface roughness distribution modelling including a more suitable method for process parameter selection according to the design criteria and improvements in the overall surface roughness of parts as compared to analytical methods. The optimized ANN based on the proposed advanced algorithm (PSOICA) represents precise estimation and faster convergence. The validity assessment confirms that the proposed methodology performs better in varied conditions and complex shapes.
Originality/value
This research fills an important gap in surface roughness distribution estimation modelling by using a test part designed for that purpose and optimized ANN models which uses purely empirical data. The novel PSOICA combination enhances the ability of the ANN to perform more accurately and quickly. The advantage in using actual surface roughness values is that all factors resulting in the creation of a rough surface are included, which is impossible if other methods are used.
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Yuanbin Wang, Robert Blache and Xun Xu
This study aims to review the existing methods for additive manufacturing (AM) process selection and evaluate their suitability for design for additive manufacturing (DfAM). AM…
Abstract
Purpose
This study aims to review the existing methods for additive manufacturing (AM) process selection and evaluate their suitability for design for additive manufacturing (DfAM). AM has experienced a rapid development in recent years. New technologies, machines and service bureaus are being brought into the market at an exciting rate. While user’s choices are in abundance, finding the right choice can be a non-trivial task.
Design/methodology/approach
AM process selection methods are reviewed based on decision theory. The authors also examine how the user’s preferences and AM process performances are considered and approximated into mathematical models. The pros and cons and the limitations of these methods are discussed, and a new approach has been proposed to support the iterating process of DfAM.
Findings
All current studies follow a sequential decision process and focus on an “a priori” articulation of preferences approach. This kind of method has limitations for the user in the early design stage to implement the DfAM process. An “a posteriori” articulation of preferences approach is proposed to support DfAM and an iterative design process.
Originality/value
This paper reviews AM process selection methods in a new perspective. The users need to be aware of the underlying assumptions in these methods. The limitations of these methods for DfAM are discussed, and a new approach for AM process selection is proposed.
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Yuran Jin, Xin Li, R. Ian Campbell and Shoufeng Ji
3D printing is believed to be driving the third industrial revolution. However, a scientometric visualizing of 3D printing research and an exploration its hotspots and emerging…
Abstract
Purpose
3D printing is believed to be driving the third industrial revolution. However, a scientometric visualizing of 3D printing research and an exploration its hotspots and emerging trends are lacking. This study aims to promote the theory development of 3D printing, help researchers to determine the research direction and provide a reference for enterprises and government to plan the development of 3D printing industry by a comprehensive understanding of the hotspots and trends of 3D printing.
Design/methodology/approach
Based on the theory of scientometrics, 2,769 literatures on the 3D printing theme were found in the Web of Science Core Collection’ Science Citation Index Expanded (SCI-EXPANDED) index between 1995-2016. These were analyzed to explore the research hotspots and emerging trends of 3D printing with the software CiteSpaceIII.
Findings
Hotspots had appeared first in 1993, grew rapidly from 2005 and peaked in 2013; hotspots in the “medical field” appeared earliest and have remained extremely active; hotspots have evolved from “drug”, “printer”, “rapid prototyping” and “3D printing” in the 1990s, through “laser-induced consolidation”, “scaffolds”, “sintering” and “metal matrix composites” in the 2000s, to the current hotspots of “stereolithography”, “laser additive manufacturing”, “medical images”; “3D bioprinting”, “titanium”, “Cstem cell” and “chemical reaction” were the emerging hotspots in recent years; “Commercial operation” and “fusion with emerging technology such as big data” may create future hotspots.
Research limitations/implications
It is hard to avoid the possibility of missing important research results on 3D printing. The relevant records could be missing if the query phrases for topic search do not appear in records. Besides, to improve the quality of data, this study selected articles and reviews as the research objects, which may also omit some records.
Originality/value
First, this is the first paper visualizing the hotspots and emerging trends of 3D printing using scientometric tools. Second, not only “burst reference” and “burst keywords” but also “cluster” and “landmark article” are selected as the evaluation factors to judge the hotspots and trends of a domain comprehensively. Third, overall perspective of hotspots and trends of 3D printing is put forward for the first time.
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Khalil Mustafa Abdulkarem Algunaid and Jichang Liu
This study aims to develop a system framework to organise, manage and evaluate 3D printing (3DP) services in the cloud and help users select the best service according to…
Abstract
Purpose
This study aims to develop a system framework to organise, manage and evaluate 3D printing (3DP) services in the cloud and help users select the best service according to application requirements.
Design/methodology/approach
Users can personalise their 3DP services based on their application requirements. The user is supplied with the performance capabilities and trust of all possible services. If the user is unable to select a service directly from the list of possible 3DP services, he/she can assign preference values for the application requirements to make a trade-off between the performance capabilities of services provided in terms of response time, manufacturing capabilities, lead time, cost and data integrity. After obtaining the finished product, the performance trust of the selected service are modified based on consumer feedback regarding their satisfaction. The accumulated input of a service's users is used to dynamically update its performance trust and is offered to new customers as a guide.
Findings
An industry case study is applied to verify the proposed methodology. The systematic order of the system framework demonstrated its efficiency in customising production based on trusted 3DP service providers.
Originality/value
The system upgraded the conventional 3DP service evaluation and selection approach. It considers the evaluation criteria of 3DP resources and the trust of service performance in the cloud context. The system favours 3DP cloud service providers. A registry tool is proposed to allow 3DP service providers to comprehensively define their services. By implementing a trust evaluation approach, 3DP service providers' trust are regularly updated based on their historical performances. In addition, a punishment mechanism is designed to motivate service providers to publish their true performance capabilities, therefore promoting a competitive environment and resulting in more reliable services.
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Michelle McClelland, Sara Grobbelaar and Natasha Sacks
This paper aims to explore the growth of the South African additive manufacturing (AM) industry over the past 31 years through the lens of the innovation system (IS) perspective…
Abstract
Purpose
This paper aims to explore the growth of the South African additive manufacturing (AM) industry over the past 31 years through the lens of the innovation system (IS) perspective, examining the actor dynamics and mechanisms that facilitated or hindered the industry’s development.
Design/methodology/approach
The study used a case study research approach, analysing semi-structured interviews with eight South African AM experts and documentary evidence. The IS framework and the realist evaluation perspective were used, using a context-intervention-mechanism-outcome (CIMO)-based event history analysis (EHA) framework to explore the actor dynamics and mechanisms of the case study.
Findings
The study used a case study research approach, analysing semi-structured interviews with eight South African AM experts and documentary evidence. The IS framework and the realist evaluation perspective were used, using a CIMO-based EHA framework to explore the actor dynamics and mechanisms of the case study.
Originality/value
This paper contributes to the South African AM industry literature by providing an overview of the industry events over the past three decades and analysing the industry through the IS framework. The study is among the first to analyse the development of the South African AM industry, presenting innovation scholars and managers with valuable decision-making support by providing insights into the innovation activities performed during each stage of the industry’s development, who performed them, the sequence in which they were performed and the outcomes they delivered.
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Alberto Boschetto, Veronica Giordano and Francesco Veniali
The paper aims to predict the surface roughness of fused deposition modelling prototypes. Since average roughness is not comprehensive, this study aims to extend the…
Abstract
Purpose
The paper aims to predict the surface roughness of fused deposition modelling prototypes. Since average roughness is not comprehensive, this study aims to extend the characterization to all the roughness parameters obtainable by a profilometric analysis.
Design/methodology/approach
A theoretical model of the 3D profile is supplied as a function of process parameters and part shape. A suitable geometry was designed and prototyped for validation. Data were measured by a profilometer and complemented by microscopic analysis. A methodology based on the proposed model was applied to optimise prototype fabrication in two practical cases.
Findings
The proposed profile is effective in describing the micro‐geometrical surface of fused deposition modelling prototypes. The third dimension enables the calculation of amplitude, spatial and hybrid roughness parameters.
Research limitations/implications
Because of mathematical assumptions and technological aspects, the validity of the model presents limitations related to the deposition angle.
Practical implications
The method is an effective tool in the process planning stage: it enables knowing in advance how to assure part specifications delivering a set of technical choices. Two practical applications point out the usability in the product development and process parameters optimisation.
Originality/value
This work fulfils an identified need to predict a complete surface characterization of fused deposition modelling technology.
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This chapter is dedicated to presenting the essential features and technical capabilities of the prototype ‘Integrated early price assessment system’, with an overview of how the…
Abstract
This chapter is dedicated to presenting the essential features and technical capabilities of the prototype ‘Integrated early price assessment system’, with an overview of how the machine learning system interacts with an expert evaluation system. The functional structure of the prototype’s operation is presented by means of an overview of the prototype’s communication flow diagram.
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This is the fourth comprehensive register of current research in marketing to appear in this Journal. It is hoped that it will prove useful as a source of information to all those…
Abstract
This is the fourth comprehensive register of current research in marketing to appear in this Journal. It is hoped that it will prove useful as a source of information to all those with interests in the subject. The projects listed do not include research work undertaken by commercial organisations or studies conducted in educational institutions where the results are not intended to be generally available. Otherwise, every effort has been made to obtain basic information from research workers willing to discuss their efforts with other interested individuals.