scholarly journals Opuntia spp. Fibre Characterisation to Obtain Sustainable Materials in the Composites Field

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2085
Author(s):  
Jessica Castellano ◽  
María D. Marrero ◽  
Zaida Ortega ◽  
Francisco Romero ◽  
Antonio N. Benitez ◽  
...  

Some studies have evaluated the use of Opuntia as reinforcement for polymeric matrices, obtaining good results in energy absorption tests and increasing the tensile elastic modulus. However, no studies focusing on the previous characterisation of the fibres and their treatment to improve compatibility with polymeric matrices have been found. This work analyses the chemical composition of Opuntia maxima (OM) and Opuntia dillenii (OD) cladodes and fibre, studying how different treatments influence it. AOAC 2000 methods were used to determine non-structural components and the Van Soest method was used to estimate structural components. Surface characteristics of the samples were also evaluated by Fourier Transform Infrared Spectroscopy (FTIR). Opuntia fibre presented higher cellulose (50–66%) and lignin (6–14%) content and lower hemicellulose (8–13%) content than Opuntia cladodes (9–14% cellulose, 20–50% hemicellulose, 1–4% lignin). Despite the variability of lignocellulosic materials, OD cladodes treated with water and acetic acid achieved an increase in the structural components. Alkaline fibre treatment removed pectin and hemicellulose from the fibre surface, slightly increasing the cellulose content. Future research should evaluate whether the treated Opuntia fibre can improve the mechanical properties of reinforced polymer.

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1022
Author(s):  
Hoang T. Nguyen ◽  
Kate T. Q. Nguyen ◽  
Tu C. Le ◽  
Guomin Zhang

The evaluation and interpretation of the behavior of construction materials under fire conditions have been complicated. Over the last few years, artificial intelligence (AI) has emerged as a reliable method to tackle this engineering problem. This review summarizes existing studies that applied AI to predict the fire performance of different construction materials (e.g., concrete, steel, timber, and composites). The prediction of the flame retardancy of some structural components such as beams, columns, slabs, and connections by utilizing AI-based models is also discussed. The end of this review offers insights on the advantages, existing challenges, and recommendations for the development of AI techniques used to evaluate the fire performance of construction materials and their flame retardancy. This review offers a comprehensive overview to researchers in the fields of fire engineering and material science, and it encourages them to explore and consider the use of AI in future research projects.


2021 ◽  
Author(s):  
Justin Carter ◽  
Kumar Vikram Singh ◽  
Fazeel Khan

Abstract The exploration of structures made of multiple materials is a growing area of research as additive manufacturing processing technologies such as fused deposition modeling (FDM) 3D printing allows for their fabrication. Such a technology allows for rapid prototyping of structural components with complex geometries or spatially distributed materials with different properties and functionalities. By selecting suitable spatial distribution of materials, the performance of structural components can be manipulated and enhanced as per different engineering application needs. For a low-cost design of structural prototypes using 3D printing processes, viscoelastic polymeric materials are often used, having inherent damping properties. In this research, vibration characteristics of thin plates which are axially graded with multiple polymeric materials are investigated. The goal is to understand the influence of material grading on the frequency and damping characteristics of graded plates. Although in literature, material grading along the thickness in designing composite laminates and their vibration characteristics are available, the performance of plates having axially graded viscoelastic polymers have not been investigated yet. Through systematic modeling and experimental plans, vibration characteristics of axially graded viscoelastic plates are presented here. In particular, the damping performance for different grading schemes is evaluated. It is anticipated that such analysis will allow accurate modeling and testing of design prototypes of structural components for future research, such as design and testing of graded panels for enhanced flutter characteristics.


2020 ◽  
Vol 10 (7) ◽  
pp. 2489 ◽  
Author(s):  
Francesca Sciarretta

This paper presents a study on the potentiality of seismic retrofitting solutions with pultruded Fiber Reinforced Polymer (FRP) profiles. This material can be used in connected frames providing lightweight, corrosion-free and reversible retrofitting of masonry buildings with the moderate requirements of surface preservation. In a hypothetical case study, an experimental program was designed; monotonic shear tests on a half-size physical model of the sample wall were performed to assess the structural performance before and after retrofitting with a basic frame of pultruded Glass Fiber Reinforced Polymer (GFRP) C-shaped profiles, connected to the masonry by steel threaded bar connections. During the tests, the drift, the diagonal displacements in the masonry and the micro-strain in the profiles were measured. The retrofitted system has proven very effective in delaying crack appearance, increasing the maximum load (+85% to +93%) and ultimate displacement (up to +303%). The failure mode switches from rocking to a combination of diagonal cracking and bed joint sliding. The gauge recordings show a very limited mechanical exploitation of the GFRP material, despite the noticeable effectiveness of the retrofit. The application seems thus promising and worth a deeper research focus. Finally, a finite element modelling approach has been developed and validated, and it will be useful to envisage the effects of the proposed solution in future research.


2020 ◽  
Vol 10 (6) ◽  
pp. 2082 ◽  
Author(s):  
Jaber E. Abu Qudeiri ◽  
Aiman Zaiout ◽  
Abdel-Hamid I. Mourad ◽  
Mustufa Haider Abidi ◽  
Ahmed Elkaseer

Electric discharge machining (EDM) is one of the most efficient manufacturing technologies used in highly accurate processing of all electrically conductive materials irrespective of their mechanical properties. It is a non-contact thermal energy process applied to a wide range of applications, such as in the aerospace, automotive, tools, molds and dies, and surgical implements, especially for the hard-to-cut materials with simple or complex shapes and geometries. Applications to molds, tools, and dies are among the large-scale initial applications of this process. Machining these items is especially difficult as they are made of hard-to-machine materials, they have very complex shapes of high accuracy, and their surface characteristics are sensitive to machining conditions. The review of this kind with an emphasis on tool and die materials is extremely useful to relevant professions, practitioners, and researchers. This review provides an overview of the studies related to EDM with regard to selection of the process, material, and operating parameters, the effect on responses, various process variants, and new techniques adopted to enhance process performance. This paper reviews research studies on the EDM of different grades of tool steel materials. This article (i) pans out the reported literature in a modular manner with a focus on experimental and theoretical studies aimed at improving process performance, including material removal rate, surface quality, and tool wear rate, among others, (ii) examines evaluation models and techniques used to determine process conditions, and (iii) discusses the developments in EDM and outlines the trends for future research. The conclusion section of the article carves out precise highlights and gaps from each section, thus making the article easy to navigate and extremely useful to the related research community.


2014 ◽  
Vol 587-589 ◽  
pp. 1424-1429 ◽  
Author(s):  
Li Hua Yang

Fiber reinforced polymer (FRP) has widely used in civil engineering due to their high strength-to-weight, high stiffness-to-weight ratios, and corrosion resistance. To solve the corrosion of the reinforcing steel in the bridge engineering and reduce the initial cost, FRP-concrete composite structure has been considered as the most effective composite form. A detailed research status survey of FRP-concrete composite beam/deck systems and their construction applications in civil engineering is presented. Several problems in future research are put forward.


Author(s):  
N. Selva Kumar ◽  
T. M. Sakthi Muruga ◽  
S. Ganapathy ◽  
K. Arulkumar

Our Experimentation finds, reaction of fibre external analysis on tensile, flexural and chemical resistance properties were studied for sisal fibre reinforced composites. Fibre surface analysis has done to produce link between fibre and the matrix to improve the mechanical properties. Fibre surface analysis were done by boiled the sisal fibres in different % of NaOH and treated the fibres in different % of NaOH, treated in acetic acid and methanol. Polyester resin have used as the matrix for preparing the composites and these properties for Natural sisal fibre reinforced composites were also studied. From the results it was observed that 25% NaOH boiled sisal fibre reinforced composites have higher tensile, flexural properties than other composites. Natural sisal fibre composites show fewer properties than treated composites. Chemical inertness properties indicate that all sisal fibre reinforced composites are resistance to all chemical agents except carbon tetra chloride.


2007 ◽  
pp. 85-95
Author(s):  
Marina Stamenovic ◽  
Slavisa Putic ◽  
Branislav Bajceta ◽  
Dragana Vitkovic

Mechanical properties of composite materials are conditioned by their structure and depend on the characteristics of structural components. In this paper is presented a numerical model by which the bending properties can be predicted on the basis of known mechanical properties of tension and pressure. Determining the relationship between these properties is justified having in mind the mechanics of fracture during bending, where the fracture takes place on the outer layer which is subjected to bending while the break ends on the layer subjected to pressure. The paper gives the values of tension, pressure and bending properties obtained by the corresponding mechanical test. A comparison of the numerical results of bending properties obtained on the basis of the model with the experimental ones, shows their satisfactory agreement. Therefore, this model can be used for some future research to predict bending properties without experiments.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2771 ◽  
Author(s):  
Bidita Salahuddin ◽  
Shaikh N. Faisal ◽  
Tajwar A. Baigh ◽  
Mohammed N. Alghamdi ◽  
Mohammad S. Islam ◽  
...  

Carbon fibre reinforced polymer composites have high mechanical properties that make them exemplary engineered materials to carry loads and stresses. Coupling fibre and matrix together require good understanding of not only fibre morphology but also matrix rheology. One way of having a strongly coupled fibre and matrix interface is to size the reinforcing fibres by means of micro- or nanocarbon materials coating on the fibre surface. Common coating materials used are carbon nanotubes and nanofibres and graphene, and more recently carbon black (colloidal particles of virtually pure elemental carbon) and graphite. There are several chemical, thermal, and electrochemical processes that are used for coating the carbonous materials onto a carbon fibre surface. Sizing of fibres provides higher interfacial adhesion between fibre and matrix and allows better fibre wetting by the surrounded matrix material. This review paper goes over numerous techniques that are used for engineering the interface between both fibre and matrix systems, which is eventually the key to better mechanical properties of the composite systems.


2001 ◽  
Vol 10 (5) ◽  
pp. 096369350101000 ◽  
Author(s):  
J. Bousoulas ◽  
P. A. Tarantili ◽  
A. G. Andreopoulos

A comparative study was made in order to evaluate the interfacial characteristics of treated aramid fibres and epoxy resins. Surface treatment by coating with phenolic resins was performed using the following two systems: a) alkaline aqueous solution of resole resin and b) solution of novolac resin containing hexamethylene-tetramine as cross-linking agent. After these treatments, the modified aramid fibres were used for the preparation of reinforced epoxy specimens. The flexural properties of these specimens were determined and the results were discussed taking into consideration the surface characteristics of the modified fibres, as derived from pull-out tests and contact angle measurements. It was shown that both coatings are adequate to promote interfacial adhesive bonding to epoxy matrices due to the chemical reactivity of phenolic resins to the epoxy matrix as well as to their affinity with the aramid fibre surface. Resole appeared more efficient than novolac as it produces uniform continuous films, shows increased reactivity due to its higher hydroxyl content and can be easily processed because it is soluble in alkaline water solutions.


2007 ◽  
Vol 23 (02) ◽  
pp. 72-81
Author(s):  
Mark Smith ◽  
Parsaoran Hutapea

Recently, many nations along with private shipbuilders have begun developing large maritime vessels using composite materials structurally. Concurrently, the US Navy has a need for research on bonded metal-composite joints. For these reasons, a literature review was conducted to establish a fundamental knowledge base of adhesive bonding and failure theories along with surface cleaning and engineering processes that would be valuable for metal-composite joint designs. It is believed that by understanding bonding and failure fundamentals, optimal surface characteristics can be targeted. Furthermore, by knowing the available cleaning and surface engineering processes, in conjunction with understanding their resulting surface topographies and compositions, creative and novel joints can be designed. This report provides the results of the literature review performed, which serves as a platform for future research aimed at optimizing bonded joints for use in naval applications.


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