Search results

1 – 4 of 4
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 11 February 2020

Rafid Hussein, Sudharshan Anandan, Myranda Spratt, Joseph W. Newkirk, K. Chandrashekhara, Misak Heath and Michael Walker

Honeycomb cellular structures exhibit unique mechanical properties such as high specific strength, high specific stiffness, high energy absorption and good thermal and acoustic…

258

Abstract

Purpose

Honeycomb cellular structures exhibit unique mechanical properties such as high specific strength, high specific stiffness, high energy absorption and good thermal and acoustic performance. This paper aims to use numerical modeling to investigate the effective elastic moduli, in-plane and out-of-plane, for thick-walled honeycombs manufactured using selective laser melting (SLM).

Design/methodology/approach

Theoretical predictions were performed using homogenization on a sample scale domain equivalent to the as-manufactured dimensions. A Renishaw AM 250 machine was used to manufacture hexagonal honeycomb samples with wall thicknesses of 0.2 to 0.5 mm and a cell size of 3.97 mm using 304 L steel powder. The SLM-manufactured honeycombs and cylindrical test coupons were tested using flatwise and edgewise compression. Three-dimensional finite element and strain energy homogenization were conducted to determine the effective elastic properties, which were validated by the current experimental outcomes and compared to analytical models from the literature.

Findings

Good agreement was found between the results of the effective Young’s moduli ratios numerical modeling and experimental observations. In-plane effective elastic moduli were found to be more sensitive to geometrical irregularity compared to out-of-plane effective moduli, which was confirmed by the analytical models. Also, it was concluded that thick-walled SLM manufactured honeycombs have bending-dominated in-plane compressive behavior and a stretch-dominated out-of-plane compressive behavior, which matched well with the simulation and numerical models predictions.

Originality/value

This work uses three-dimensional finite element and strain energy homogenization to evaluate the effective moduli of SLM manufactured honeycombs.

Details

Rapid Prototyping Journal, vol. 26 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

Access Restricted. View access options
Article
Publication date: 27 April 2020

Myranda Spratt, Sudharshan Anandan, Rafid Hussein, Joseph W. Newkirk, K. Chandrashekhara, Misak Heath and Michael Walker

The purpose of this study is to analyze the build quality and compression properties of thin-walled 304L honeycomb structures manufactured by selective laser melting. Four…

135

Abstract

Purpose

The purpose of this study is to analyze the build quality and compression properties of thin-walled 304L honeycomb structures manufactured by selective laser melting. Four honeycomb wall thicknesses, from 0.2 to 0.5 mm, were built and analyzed.

Design/methodology/approach

The density of the honeycombs was changed by increasing the wall thickness of each sample. The honeycombs were tested under compression. Differences between the computer-assisted design model and the as-built structure were quantified by measuring physical dimensions. The microstructure was evaluated by optical microscopy, density measurements and microhardness.

Findings

The Vickers hardness of the honeycomb structures was 209 ± 14 at 50 g load. The compression ultimate and yield strength of the honeycomb material were shown to increase as the wall thickness of the honeycomb samples increased. The specific ultimate strength also increased with wall thickness, while the specific yield stress of the honeycomb remained stable at 42 ± 2.7 MPa/g/cm3. The specific ultimate strength minimized near 0.45 mm wall thickness at 82 ± 5 MPa/g/cm3 and increased to 134 ± 3 MPa/g/cm3 at 0.6 mm wall thickness.

Originality/value

This study highlights a single lightweight metal structure, the honeycomb, built by additive manufacturing (AM). The honeycomb is an interesting structure because it is a well-known building material in the lightweight structural composites field but is still considered a relatively complex geometric shape to fabricate. As shown here, AM techniques can be used to make complex geometric shapes with strong materials to increase the design flexibility of the lightweight structural component industry.

Details

Rapid Prototyping Journal, vol. 26 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

Access Restricted. View access options
Article
Publication date: 14 June 2021

Christina Louise Romero-Ivanova, Paul Cook and Greta Faurote

This study centers on high school pre-teacher education students’ reviews of their peers’ digital stories. The purpose of this study is twofold: to bring digital storytelling to…

462

Abstract

Purpose

This study centers on high school pre-teacher education students’ reviews of their peers’ digital stories. The purpose of this study is twofold: to bring digital storytelling to the forefront as a literacy practice within classrooms that seeks to privilege students’ voices and experiences and also to encapsulate the authors’ different experiences and perspectives as teachers. The authors sought to understand how pre-teacher education candidates analyzed, understood and made meaning from their classmates’ digital stories using the seven elements of digital storytelling (Dreon et al., 2011).

Design/methodology/approach

Using grounded theory (Charmaz, 2008) as a framework, the question of how do high school pre-teacher education program candidates reflectively peer review their classmates’ digital stories is addressed and discussed through university and high school instructors’ narrative reflections. Through peer reviews of their fellow classmates’ digital stories, students were able to use the digital storytelling guide that included the seven elements of digital storytelling planning to critique and offer suggestions. The authors used the 2018–2019 and 2019–2020 cohorts’ digital stories, digital storytelling guides and peer reviews to discover emerging categories and themes and then made sense of these through narrative analysis. This study looks at students’ narratives through the contexts of peer reviews.

Findings

The seven elements of digital storytelling, as noted by Dreon et al. (2011, p. 5), which are point of view, dramatic question, emotional content, the gift of your voice, the power of the soundtrack, economy and pacing, were used as starting points for coding students’ responses in their evaluations of their peers’ digital stories. Situated on the premise of 21st century technologies as important promoters of differentiated ways of teaching and learning that are highly interactive (Greenhow et al., 2009), digital stories and students’ reflective practices of peer reviewing were the foundational aspects of this paper.

Research limitations/implications

The research the authors have done has been in regards to reviewing and analyzing students’ peer reviews of their classmates’ digital stories, so the authors did not conduct a research study empirical in nature. What the authors have done is to use students’ artifacts (digital story, digital storytelling guides and reflections/peer reviews) to allow students’ authentic voices and perspectives to emerge without their own perspectives marring these. The authors, as teachers, are simply the tools of analysis.

Practical implications

In reading this paper, teachers of different grade levels will be able to obtain ideas on using digital storytelling in their classrooms first. Second, teachers will be able to obtain hands-on tools for implementing digital storytelling. For example, the digital storytelling guide to which the authors refer (Figure 1) can be used in different subject areas to help students plan their stories. Teachers will also be able to glean knowledge on using students’ peer reviews as a kind of authentic assessment.

Social implications

The authors hope in writing and presenting this paper is that teachers and instructors at different levels, K-12 through higher education, will consider digital storytelling as a pedagogical and learning practice to spark deeper conversations within the classroom that flow beyond margins and borders of instructional settings out into the community and beyond. The authors hope that others will use opportunities for storytelling, digital, verbal, traditional writing and other ways to spark conversations and privilege students’ voices and lives.

Originality/value

As the authors speak of the original notion of using students’ crucial events as story starters, this is different than prior research for digital storytelling that has focused on lesson units or subject area content. Also, because the authors have used crucial events, this is an entry point to students’ lives and the creation of rapport within the classroom.

Details

English Teaching: Practice & Critique, vol. 20 no. 2
Type: Research Article
ISSN: 1175-8708

Keywords

Access Restricted. View access options
Article
Publication date: 2 August 2013

Mark Tadajewski

Women and marketing have had a complicated relationship for a considerable time. They have often been involved with marketing‐type practices for longer than we have appreciated to…

462

Abstract

Purpose

Women and marketing have had a complicated relationship for a considerable time. They have often been involved with marketing‐type practices for longer than we have appreciated to date. Against considerable odds, some have carved out careers in academia and practice that have to be admired. The purpose of this paper is to explore the work of two pioneer contributors to marketing.

Design/methodology/approach

This paper engages in a close reading of the work of two female contributors. Their writing is placed in historical context which helps reveal the obstacles they had to overcome to succeed.

Findings

Female teachers, lecturers and practitioners had an important role to play in theorising consumer practice and helping people to successfully negotiate a complex marketplace replete with new challenges, difficulties and sometimes mendacious marketers seeking to profit from the limited knowledge consumers possessed.

Originality/value

This paper explores the writings of a practitioner and scholar respectively whose work has merited only limited attention previously. More than this, it links the arguments that are made to the papers that appear in the rest of the special issue.

Details

Journal of Historical Research in Marketing, vol. 5 no. 3
Type: Research Article
ISSN: 1755-750X

Keywords

1 – 4 of 4
Per page
102050