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Article
Publication date: 12 June 2017

Fabienne Touchard, Michel Boustie, Laurence Chocinski-Arnault, Pedro Pascual González, Laurent Berthe, Davi de Vasconcellos, Luigi Sorrentino, Pawel Malinowski and Wieslaw Ostachowicz

The purpose of this paper is to study the damage induced in “green” and synthetic composites under impact loading.

Abstract

Purpose

The purpose of this paper is to study the damage induced in “green” and synthetic composites under impact loading.

Design/methodology/approach

The study was focussed on epoxy-based composites reinforced with woven hemp or glass fibres. Six assessment techniques were employed in order to analyse and compare impact damages: eye observation, back face relief, terahertz spectroscopy, laser vibrometry, x-ray micro-tomography and microscopic observations.

Findings

Different damage detection thresholds for each material and technique were obtained. Damage induced by mechanical and laser impacts showed relevant differences, but the damage mechanisms are similar in both types of impact: matrix cracks, fibre failure, debonding at the fibres/matrix interface and delamination. Damage shape on back surfaces is similar after mechanical or laser impacts, but differences were detected inside samples.

Originality/value

The combination of these six diagnoses provides complementary information on the damage induced by mechanical or laser impacts in the studied green and synthetic composites.

Details

International Journal of Structural Integrity, vol. 8 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 11 November 2014

R. Ecault, M. Boustie, L. Berthe, F. Touchard, L. Chocinski-Arnault, H. Voillaume and B. Campagne

The purpose of this paper is to develop a laser shock adhesion test (LASAT) and evaluate its ability to reveal various bond qualities of stuck carbon fiber reinforced…

Abstract

Purpose

The purpose of this paper is to develop a laser shock adhesion test (LASAT) and evaluate its ability to reveal various bond qualities of stuck carbon fiber reinforced polymer (CFRP) industrial assemblies.

Design/methodology/approach

Four grades of adhesion were prepared by release agent contamination of CFRP prior to assembly. Laser shots were performed at different intensities on these samples.

Findings

To characterize and quantify the damage created by the propagation of shock waves in the bonded material, several diagnoses were used (confocal microscopy, ultra-sound inspection and cross-sections microscopy). These three post-mortem techniques are complementary and provide consistent results.

Originality/value

The combination of these diagnoses along with the LASAT technique provides relevant information on the bond quality in agreement with GIC values measured by the University of Patras.

Details

International Journal of Structural Integrity, vol. 5 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 27 January 2020

Ankang Liu, Bing Wang and Fei Li

This paper aims to study the effect of elevated temperature on the compression behaviour of carbon fibre polyphenylene sulphide (CF/PPS) laminates notched and unnotched…

Abstract

Purpose

This paper aims to study the effect of elevated temperature on the compression behaviour of carbon fibre polyphenylene sulphide (CF/PPS) laminates notched and unnotched specimens made by film stacking method (FSM).

Design/methodology/approach

The surface of CF was coated with a silane coupling agent to form an effective transition layer with PPS, so as to enhance the interfacial interaction between CF and PPS. Considering the influence of fabrication pressure, forming temperature and cooling rate on the properties of laminates to obtain a reasonable preparation process. Conducting a compressive experiment of notched and unnotched specimens at different temperatures, which failure modes were examined by scanning electron microscope and stereo microscope.

Findings

The experimental observations highlight that with the increase of temperature, the transition failure mode from fibre broken to kink-band appeared in unnotched specimens, which were closely attributed to the matrix state. The notched specimens appeared more complex failure mode, which can be attributed to the joint effect of temperature and opening hole.

Research implications

A simple way of FSM for composite material laminates has been developed by using woven CF and PPS films.

Originality/value

The outcome of this study will help to understand the compression response mechanism of composite materials made by FSM at different temperature.

Details

Pigment & Resin Technology, vol. 50 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 3 December 2018

Magdalena Mieloszyk, Katarzyna Majewska and Wieslaw Ostachowicz

The purpose of this paper is to discuss the application of THz spectroscopy for the inspection and evaluation of the internal structure of complex samples with honeycomb fillers.

Abstract

Purpose

The purpose of this paper is to discuss the application of THz spectroscopy for the inspection and evaluation of the internal structure of complex samples with honeycomb fillers.

Design/methodology/approach

Three complex samples with honeycomb fillers are investigated using THz spectrometer in order to determine the applicability of chosen non-destructive method for the analysis of internal structure of structural components. The first analysed sample has aluminium honeycomb filler with some cells filled with water. The aim of the analysis is to distinguish empty and full cells. The other two sandwich samples are made of different non-metallic components and for them the possibility of THz spectroscopy application is analysed.

Findings

The empty and full cells in metal honeycomb filler were easily distinguished due to different absorption coefficients of electromagnetic waves in THz range for air and water. It was especially visible for frequency domain. The THz spectroscopy was able to inspect the non-metallic samples internal structures and distinguish skins (with layers), honeycomb fillers and adhesive layers between them. It was also possible to detect, localise and determine the size of a local damage of honeycomb walls due to impact influence.

Originality/value

The present study is an original research work. There are very limited literature papers which present analyses of internal structures of sandwich elements using THz spectroscopy and investigate utility of the method for mechanical damage and contamination (water) detection and localisation.

Details

International Journal of Structural Integrity, vol. 9 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 19 July 2021

Kawaljit Singh Randhawa and Ashwin Patel

The mechanical and tribological properties of polymers and polymer composites vary with different environmental conditions. This paper aims to review the influence of…

Abstract

Purpose

The mechanical and tribological properties of polymers and polymer composites vary with different environmental conditions. This paper aims to review the influence of humidity/water conditions on various polymers and polymer composites' mechanical properties and tribological behaviors.

Design/methodology/approach

The influence of humidity and water absorption on mechanical and tribological properties of various polymers, fillers and composites has been discussed in this paper. Tensile strength, modulus, yield strength, impact strength, COF and wear rates of polymer composites are compared for different environmental conditions. The interaction between the water molecules and hydrophobic polymers is also represented.

Findings

Pure polymer matrices show somewhat mixed behavior in humid environments. Absorbed moisture generally plasticizes the epoxies and polyamides and lowers the tensile strength, yield strength and modulus. Wear rates of PVC generally decrease in humid environments, while for polyamides, it increases. Fillers like graphite and boron-based compounds exhibit low COF, while MoS2 particulate fillers exhibit higher COF at high humidity and water conditions. The mechanical properties of fiber-reinforced polymer composites tend to decrease as the rate of humidity increases while the wear rates of fiber-reinforced polymer composites show somewhat mixed behavior. Particulate fillers like metals and advanced ceramics reinforced polymer composites exhibit low COF and wear rates as the rate of humidity increases.

Originality/value

The mechanical and tribological properties of polymers and polymer composites vary with the humidity value present in the environment. In dry conditions, wear loss is determined by the hardness of the contacting surfaces, which may not effectively work for high humid environments. The tribological performance of composite constituents, i.e. matrix and fillers in humid environments, defines the overall performance of polymer composite in said environments.

Details

Industrial Lubrication and Tribology, vol. 73 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 January 1992

M.J. Ridley

The QUALCAT project at the University of Bradford attempted to apply automated quality control to databases of bibliographic records. Sets of records, putative duplicates…

Abstract

The QUALCAT project at the University of Bradford attempted to apply automated quality control to databases of bibliographic records. Sets of records, putative duplicates, that appeared to be for the same monograph were grouped together and an expert system used to determine whether they were in fact duplicates, and if so which were the best records. This paper outlines the expert system used and discusses problems and further developments in automated examination of bibliographic records.

Details

Program, vol. 26 no. 1
Type: Research Article
ISSN: 0033-0337

Article
Publication date: 1 March 2022

Paulo Mourao

In this article, the author discusses the influence of technological development on the survival of European parties since the Second World War.

Abstract

Purpose

In this article, the author discusses the influence of technological development on the survival of European parties since the Second World War.

Design/methodology/approach

The database comprises more than 200 parties and the political forces observed in 20 countries.

Findings

The author find that Internet users as a proportion of the population and a higher value of secure servers in an economy tend to strengthen the duration of parties since their first electoral participation.

Originality/value

This is the first paper discussing parties' survival in democratic regimens as depending on the technological development.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 24 May 2013

Christina Goulding, Avi Shankar and Robin Canniford

Studies of marketplace cultures emphasize the benefits of communal consumption and explain the ways that brand managers can leverage subcultures and brand communities. The…

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Abstract

Purpose

Studies of marketplace cultures emphasize the benefits of communal consumption and explain the ways that brand managers can leverage subcultures and brand communities. The ephemeral and often non‐commercial nature of consumer tribes means that they are more difficult to manage. This paper, aims to suggest that a necessary pre‐requisite for understanding how to engage with consumer tribes is to identify how consumers become members of tribes.

Design/methodology/approach

Data are drawn from a five‐year ethnographic study of the archetypical club culture tribe that utilized a variety of data collection methods including participant observation and in‐depth interviewing.

Findings

The paper identifies “learning to be tribal” as a communal practice that occurs through three interconnected processes of engagement, imagination and alignment.

Originality/value

This paper makes three contributions: it clearly distinguishes between the three main forms of communal consumption found in the marketing literature; it identifies how consumer tribes are formed; and it questions received wisdom and shows how tribal theory can guide managers to offer products and services as learning resources that facilitate tribal practices.

Details

European Journal of Marketing, vol. 47 no. 5/6
Type: Research Article
ISSN: 0309-0566

Keywords

Article
Publication date: 7 May 2019

Rune Dall Jensen, Sissel Ravn and Mette Krogh Christensen

Education of the surgeon and development of surgical expertise have been debated for centuries. Today, research in surgical education applies terms and methods from other…

Abstract

Purpose

Education of the surgeon and development of surgical expertise have been debated for centuries. Today, research in surgical education applies terms and methods from other performance domains such as sport and music. However, there still seems to be a lack of consensus as to how talent may be brought into the discourse about surgical education. Especially, when it comes to identifying and developing trainees who in the future will perform better than the average surgeon.

Design/methodology/approach

This five-step scoping study aims to map existing literature about talent identification, talent development and development of expertise in the domains of surgery, sport and music in the period of 1985-2014.

Findings

A total of 242 studies, divided in the four domains of surgery (69 studies), sport (115 studies), music (34 studies) and cross-disciplinary studies (24 studies) published in the period 1985-2014 were included.

Originality/value

Informed by the performance domains of sports and music and their inclusion of a holistic, ecological approach to research, this study suggests that research in surgical education may benefit from broadening its view on talent by including psychosocial variables and environmental, demographic and structural influencers when considering how surgical talent may be identified and developed.

Details

European Journal of Training and Development, vol. 43 no. 3/4
Type: Research Article
ISSN: 2046-9012

Keywords

Article
Publication date: 6 June 2016

Martin Skote and Imran Halimi Ibrahim

The cylindrical wake flow is an important part of many engineering applications, including wake turbulence, acoustic noise, and lift/drag forces on bodies. The suppression…

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Abstract

Purpose

The cylindrical wake flow is an important part of many engineering applications, including wake turbulence, acoustic noise, and lift/drag forces on bodies. The suppression of von Kármán vortex street (VKS) is an important goal for flow control devices. The paper aims to discuss these issues.

Design/methodology/approach

The linear plasma synthetic jet actuator (L-PSJA) is utilized as a flow control device to suppress the VKS formation. Different configurations of the device is studied numerically.

Findings

Of the 12 configurations that were investigated, five configurations were able to suppress the formation of the VKS.

Originality/value

For the first time, the L-PSJA has been shown (through numerical simulations) to be able to suppress VKS.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

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