1,720,997 research outputs found
Editorial for Special Issue: Performance Enhancement of Advanced Composites and Bio-Based Composites through a Hybrid Approach: Opportunities and Challenges
No full textThe hybridisation of two or more fibres is a technique in which the benefits of each reinforcing material can be combined to achieve a composite that demonstrates better and improved properties for various advanced engineering applications [...
Post-impact static and cyclic flexural characterisation of hemp fibre reinforced laminates
No full textThe suitability for use of plant fibre composites after an impact event is still an open issue in literature. In this work, hemp fibre reinforced laminates have been subjected to cyclic flexural tests following falling weight impact at 12, 16 and 20J. At these energies, still quite far from penetration, which was at about 40J, damage starts to be increasingly apparent on both laminate surfaces. Post-impact flexural tests have been monitored using acoustic emission. Laminates with a sufficiently strong fibre-matrix interface have been obtained, as revealed from the impact hysteresis cycles and electron microscopy damage characterisation. However, a quite significant decrease of flexural properties and an increase of unrecoverable deformation after cyclical loading were also revealed with growing impact energies, in particular passing from 12 to 16J. (C) 2011 Elsevier Ltd. All rights reserved
Influence of Water Absorption on the Low Velocity Falling Weight Impact Damage Behaviour of Flax/Glass Reinforced Vinyl Ester Hybrid Composites
No full textDue to rigorous new environmental legislations, automotive, marine, aerospace, and construction sectors have redirected their focus into using more recyclable, sustainable, and environmentally friendly lightweight materials driven by strengthening resource efficiency drive. In this study, the influence of moisture absorption on flax and flax/glass hybrid laminates is presented with the aim to investigating their low velocity impact behaviour. Three different types of composite laminates namely, flax fibre reinforced vinyl ester, flax fibre hybridised glass fibre and glass fibre reinforced vinyl ester composites were fabricated using resin infusion technique. The moisture immersion tests were undertaken by immersing the different specimens in sea water bath at room temperature and 70 °C at different time durations. The low velocity falling weight impact testing was performed at 25 Joules of incident energy level and impact damage behaviour was evaluated at both ageing conditions using scanning electron microscopy (SEM) and X-ray microcomputed tomography (micro CT). The percentage of moisture uptake was decreased for flax vinyl ester specimens with glass fibre hybridisation. The maximum percentage of weight gain for flax fibre, flax/glass hybrid and glass fibre reinforced composites immersed at room temperature for 696 h is recorded at 3.97%, 1.93%, and 0.431%, respectively. The hybrid composite exhibited higher load and energy when compared flax/vinyl ester composite without hybridisation, indicating the hybrid system as a valid strategy towards achieving improved structural performance of natural fibre composites. The moisture absorption behaviour of these composites at room was observed to follow Fickian behaviour
Effects of Hybridisation on the Low Velocity Falling Weight Impact and Flexural Properties of Flax-Carbon/Epoxy Hybrid Composites
No full textThe trend of research and adoption of natural plant-based fibre reinforced composites is increasing, with traditional synthetic fibres such as carbon and glass experiencing restrictions placed on their manufacture and use by legislative bodies due to their environmental impact through the entire product life cycle. Finding suitable alternatives to lightweight and high-performance synthetic composites will be of benefit to the automotive, marine and aerospace industries. This paper investigates the low-velocity impact (LVI) and flexural properties and damage characteristics of flax-carbon/epoxy hybrid composites to be used in structural lightweight applications. LVI, for example, is analogous to several real-life situations, such as damage during manufacture, feasibly due to human error such as the dropping of tools and mishandling of the finished product, debris strikes of aircraft flight, or even the collision of a vessel with another. Carbon fibre has been hybridised with flax fibres to achieve enhanced impact and flexural performance. The failure mechanisms of woven flax and flax-carbon epoxy hybrid composites have been further analysed using Scanning Electron Microscopy (SEM). It was observed from the experimental results that carbon fibre hybridisation has a significant effect on the impact and flexural properties and their damage modes. The results obtained from this study exhibited that the flexural strength and modulus of plain flax/epoxy composite increase significantly from 95.66 MPa to 425.87 MPa and 4.78 GPa to 17.90 GPa, respectively, with carbon fibre hybridisation. This significant improvement in flexural properties would provide designers with important information to make informed decisions during material selection for lightweight structural applications
Unsaturated Polyester Resins: Blends, Interpenetrating Polymer Networks, Composites, and Nanocomposites
No full textPlastic Pollution and Framework Towards Sustainable Plastic Waste Management in Nigeria: Case Study
No full textPlastic pollution and its environmental consequence are on the rise globally. In Nigeria, the proliferation of plastic bottle and sachet water (PBSW) manufacturing companies in various parts of the country has led to an increase in plastic waste generation. Existing studies have identified challenges and the critical need for the adoption of sustainable solutions to mitigate its adverse environmental impact, especially for developing countries. Therefore, the motivation for this study stems from the urgent need for a progressive shift in the studies focused on feasible solutions to the common challenges and strategies for implementation. This study aims to investigate the identified challenges of a lack of awareness and waste management of single-use plastics in Nigeria, towards achieving a circular economy of plastic waste whilst considering its socio-economic context. This study used a mixed method approach combining quantitative and qualitative data through interviews and questionnaires to investigate awareness on the impact of plastic pollution amongst key stakeholders in plastic waste management in the UNN. The potential of introducing a DRS in the sustainable collection of single-use plastic bottle and sachet water waste was also explored. The result reveals the perceived consequence of plastic pollution is short-term, at the level of mesoplastics, physically observed as plastic litter (68.2%), leading to a blockage of canals (65.0%), an excessive rate of flooding (19.1%) and other related issues; effective channels of creating awareness and educating the public on plastic pollution are social media (48.3%), school education (23.3%), mass media (21.7%), and others (6%). An implementation framework for sustainable plastic waste collection was developed from the research findings, adapting the Norwegian Deposit Return Scheme (DRS) to suit the current socio-economic context of the population. Additionally, awareness can be increased through targeted government policies that reward sustainable plastic waste management practices, public awareness campaigns, and the use of social media
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