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Article
Publication date: 16 January 2017

Shahrain Mahmood, A.J. Qureshi, Kheng Lim Goh and Didier Talamona

This paper aims to discuss the effect of changes of a comprehensive list of process parameters on part scalability and tensile strength of fused filament fabrication (FFF) printed…

838

Abstract

Purpose

This paper aims to discuss the effect of changes of a comprehensive list of process parameters on part scalability and tensile strength of fused filament fabrication (FFF) printed parts. A number of parameters hitherto not studied such as cross-sectional area and its interaction with number of shells and infill density are presented and studied.

Design/methodology/approach

From a preliminary investigation, results have shown that varying the process parameters affects the ultimate tensile strength (UTS) of a FFF printed component, with component scale and number of shells as the two most significant parameters affecting the UTS. A further investigation based on the interactions of four process parameters, specimen width, b, specimen thickness, h, number of shells, n, and infill density, i, and their effects on the UTS was performed. Taguchi’s design of experiment was used to develop an experimental plan in this investigation. Specimens were printed and tested for their tensile strength until fracture and the results analyzed.

Findings

Results obtained support an inverse relationship between part scalability, change in cross-sectional area and the UTS of a FFF printed part. The UTS results were calculated in line with conventional method based on the gross cross-sectional area of A = (b × h).

Originality/value

The paper investigates the effect of part scalability on the UTS of FFF printed parts and evaluates the conventional method of calculating material tensile strength of FFF printed parts using the gross cross-sectional area of A = (b × h). The results of this findings show that the conventional method cannot be used as FFF printed parts consists of partially filled parts and not a solid component.

Details

Rapid Prototyping Journal, vol. 23 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 18 April 2017

Shahrain Mahmood, A.J. Qureshi, Kheng Lim Goh and Didier Talamona

This paper aims to investigate the tensile strength of partially filled fused filament fabrication (FFF) printed parts with respect of cross-sectional geometry of partially filled…

336

Abstract

Purpose

This paper aims to investigate the tensile strength of partially filled fused filament fabrication (FFF) printed parts with respect of cross-sectional geometry of partially filled test pieces. It was reported in the authors’ earlier work that the ultimate tensile strength (UTS) is inversely proportional to the cross-sectional area of a specimen, whereas the number of shells and infill density are directly proportional to the UTS with all other parameters being held constant. Here, the authors present an in-depth evaluation of the phenomenon and a parametric model that can provide useful estimates of the UTS of the printed part by accounting for the dimensions of the solid floor/roof layers, shells and infills.

Design/methodology/approach

It was found that partially filled FFF printed parts consist of hollow sections. Because of these voids, the conventional method of determining the UTS via the gross cross-sectional area given by A = b × h, where b and h are the width and thickness of the printed part, respectively, cannot be used. A mathematical model of a more accurate representation of the cross-sectional area of a partially filled part was formulated. Additionally, the model was extended to predict the dimensions as well as the lateral distortion of the respective features within a printed part using input values from the experimental data.

Findings

The result from this investigation shows that to calculate the UTS of a partially filled FFF part, the calculation based on the conventional approach is not sufficient. A new meta-model is proposed which takes into account the geometry of the internal features to give an estimate of the strength of a partially filled printed part that is closer to the value of the strength of the material that is used for fabricating the part.

Originality/value

This paper investigates the tensile strength of a partially filled FFF printed part. The results have shown that the tensile strength of a partially filled part can be similar to that of a solid part, at a lower cost: shorter printing time and lower material usage. By taking into account the geometries within a printed part, the cross-sectional area can be accurately represented. The mathematical model which was developed would aid end-users to predict the tensile strength for a given set of input values of the process parameters.

Details

Rapid Prototyping Journal, vol. 23 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 8 July 2014

Hui Lin and Brendan Luyt

– The purpose of this paper is to investigate the role of the National Library of Singapore in the life of Singaporeans.

1440

Abstract

Purpose

The purpose of this paper is to investigate the role of the National Library of Singapore in the life of Singaporeans.

Design/methodology/approach

The paper uses historical research. McMillan and Chavis’ theory of sense of community is adopted as the analytical framework to delineate the role of the National Library of Singapore.

Findings

The paper finds that the National Library of Singapore plays an important role in fostering a sense of community among Singaporeans. The transformation of the library to a truly public institution in 1950s effectively enlarged its boundaries. Upon joining the community of the library, local Singaporeans underwent a bidirectional process of influencing and being influenced. The library made strenuous efforts to meet the needs of Singaporeans in myriad ways, resulting in reinforcement of the sense of community among Singaporeans. A shared emotional connection in the community was engendered as a result of the frequent contact and high-quality interaction.

Originality/value

While being influenced by various social and cultural frameworks under which it operates, the library actively takes part in and influences the society. The study of the library in the life of the users via the lens of sense of community provides a perspective to further understand the potential and power of libraries and how libraries can positively contribute to the society at large.

Details

Journal of Documentation, vol. 70 no. 4
Type: Research Article
ISSN: 0022-0418

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Article
Publication date: 19 June 2007

Dahlia Shamsuddin

240

Abstract

Details

Reference Reviews, vol. 21 no. 5
Type: Research Article
ISSN: 0950-4125

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Article
Publication date: 22 April 2022

Wee-Kheng Tan and Chun Yu Hsu

Coronavirus disease 2019-related fake news consistently appears on social media. This study uses appraisal theory to analyze the impact of such rumors on individuals' emotions…

1347

Abstract

Purpose

Coronavirus disease 2019-related fake news consistently appears on social media. This study uses appraisal theory to analyze the impact of such rumors on individuals' emotions, motivations, and intentions to share fake news. Furthermore, the concept of psychological distance and construal level theory are used in combination with appraisal theory to compare toilet paper shortages and celebrity scandal rumors.

Design/methodology/approach

Data collected from 299 Taiwanese respondents to 150 toilet paper shortage-related and 149 celebrity gossip-related questionnaires were processed using partial least squares regression and multigroup analysis.

Findings

In both cases, surprise is felt most intensely. However, unlike in the celebrity fake news scenario, worry plays a prominent role in driving the altruistic sharing motivation related to the toilet paper shortage rumor. Furthermore, while emotional attributes (basic or self-conscious, concrete, or abstract) serve as a guide for how emotions change with psychological distance, the degree to which an emotion is relevant to the fake news context is key to its manifestation.

Originality/value

This study examines the impact of individuals' emotions on their motivations and intention to share fake news, applying the appraisal theory and the psychological distance concept in a single study to fake news sharing intention. It evaluates the relationship between psychological distance and emotions, revealing that it is not absolute and need not necessarily shift according to psychological distance change; rather, the relationship is context-sensitive.

Details

Online Information Review, vol. 47 no. 1
Type: Research Article
ISSN: 1468-4527

Keywords

Available. Content available
Book part
Publication date: 9 September 2024

Muhammad Hassan Raza

Free Access. Free Access

Abstract

Details

The Multilevel Community Engagement Model
Type: Book
ISBN: 978-1-83797-698-0

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Article
Publication date: 27 January 2021

Irina Tatiana Garces and Cagri Ayranci

A review on additive manufacturing (AM) of shape memory polymer composites (SMPCs) is put forward to highlight the progress made up to date, conduct a critical review and show the…

1142

Abstract

Purpose

A review on additive manufacturing (AM) of shape memory polymer composites (SMPCs) is put forward to highlight the progress made up to date, conduct a critical review and show the limitations and possible improvements in the different research areas within the different AM techniques. The purpose of this study is to identify academic and industrial opportunities.

Design/methodology/approach

This paper introduces the reader to three-dimensional (3 D) and four-dimensional printing of shape memory polymers (SMPs). Specifically, this review centres on manufacturing technologies based on material extrusion, photopolymerization, powder-based and lamination manufacturing processes. AM of SMPC was classified according to the nature of the filler material: particle dispersed, i.e. carbon, metallic and ceramic and long fibre reinforced materials, i.e. carbon fibres. This paper makes a distinction for multi-material printing with SMPs, as multi-functionality and exciting applications can be proposed through this method. Manufacturing strategies and technologies for SMPC are addressed in this review and opportunities in the research are highlighted.

Findings

This paper denotes the existing limitations in the current AM technologies and proposes several directions that will contribute to better use and improvements in the production of additive manufactured SMPC. With advances in AM technologies, gradient changes in material properties can open diverse applications of SMPC. Because of multi-material printing, co-manufacturing sensors to 3D printed smart structures can bring this technology a step closer to obtain full control of the shape memory effect and its characteristics. This paper discusses the novel developments in device and functional part design using SMPC, which should be aided with simple first stage design models followed by complex simulations for iterative and optimized design. A change in paradigm for designing complex structures is still to be made from engineers to exploit the full potential of additive manufactured SMPC structures.

Originality/value

Advances in AM have opened the gateway to the potential design and fabrication of functional parts with SMPs and their composites. There have been many publications and reviews conducted in this area; yet, many mainly focus on SMPs and reserve a small section to SMPC. This paper presents a comprehensive review directed solely on the AM of SMPC while highlighting the research opportunities.

Details

Rapid Prototyping Journal, vol. 27 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

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