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1 – 10 of 26Abdurra’uf Mukhtar Gora, Jayaprakash Jaganathan, Mohammed Parvez Anwar and Hau Y. Leung
The purpose of this paper is to present the results of experimental and theoretical studies on the flexural capacity of reinforced concrete (RC) beams strengthened using…
Abstract
Purpose
The purpose of this paper is to present the results of experimental and theoretical studies on the flexural capacity of reinforced concrete (RC) beams strengthened using externally bonded bi-directional glass fibre reinforced polymer (GFRP) composites and different end anchorage systems.
Design/methodology/approach
A series of nine RC beams with a length of 1,600 mm and a cross-section of 200 mm depth and 100 mm width were prepared and externally strengthened in flexure with bi-directional GFRP composites. These strengthened beams were anchored with three different end anchorage systems namely closed GFRP wraps, GFRP U-wraps and mechanical anchors. All these beams were tested with four-point bending system up to failure. The experimental results are compared with the theoretical results obtained using the relevant design guidelines.
Findings
The experimental results demonstrate a significant increase in the flexural performance of the GFRP strengthened beams with regard to the ultimate load carrying capacity and stiffness. The results also show that GFRP strengthened beams without end anchorages experienced intermediate concrete debonding failure at the GFRP plate end, whereas all the GFRP strengthened beams with different end anchorage systems failed in rupture of GFRP with concrete crushing. The theoretical results revealed no significant difference among the relevant design guidelines with regard to the predicted ultimate moment capacities of the bi-directional GFRP strengthened RC beams. However, the results show that ACI Committee 440 Report (2008) design recommendation provides reasonably acceptable predictions for the ultimate moment capacities of the tested beams strengthened externally with bi-directional GFRP reinforcement followed by FIB Bulletin 14 (2001) and eventually by JSCE (1997).
Originality/value
The research work presented in this manuscript is authentic and could contribute to the understanding of the overall behaviour of RC beams strengthened with FRP and different end anchorage systems under flexural loading.
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Isaac Ferreira, Margarida Machado, Fernando Alves and António Torres Marques
In industry, fused filament fabrication (FFF) offers flexibility and agility by promoting a reduction in costs and in the lead-time (i.e. time-to-market). Nevertheless, FFF parts…
Abstract
Purpose
In industry, fused filament fabrication (FFF) offers flexibility and agility by promoting a reduction in costs and in the lead-time (i.e. time-to-market). Nevertheless, FFF parts exhibit some limitations such as lack of accuracy and/or lower mechanical performance. As a result, some alternatives have been developed to overcome some of these restrictions, namely, the formulation of high performance polymers, the creation of fibre-reinforced materials by FFF process and/or the design of new FFF-based technologies for printing composite materials. This work aims to analyze these technologies.
Design/methodology/approach
This work aims to study and understand the advances in the behaviour of 3D printed parts with enhanced performance by its reinforcement with several shapes and types of fibres from nanoparticles to continuous fibre roving. Thus, a comprehensive survey of significant research studies carried out regarding FFF of fibre-reinforced thermoplastics is provided, giving emphasis to the most relevant and innovative developments or adaptations undergone at hardware level and/or on the production process of the feedstock.
Findings
It is shown that the different types of reinforcement present different challenges for the printing process with different outcomes in the part performance.
Originality/value
This review is focused on joining the most important researches dedicated to the process of FFF-printed parts with different types reinforcing materials. By dividing the reinforcements in categories by shape/geometry and method of processing, it is possible to better quantify performance improvements.
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Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…
Abstract
Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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Examines the thirteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…
Abstract
Examines the thirteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder…
Abstract
This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder metallurgy and composite material processing are briefly discussed. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for 1994‐1996, where 1,370 references are listed. This bibliography is an updating of the paper written by Brannberg and Mackerle which has been published in Engineering Computations, Vol. 11 No. 5, 1994, pp. 413‐55.
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B.C. Samanta, T. Maity, S. Dalai and A.K. Banthia
The purpose of this paper is to evaluate the mechanical properties of glass fibre reinforced epoxy composites modified with amine‐terminated poly (ethylene glycol) benzoate…
Abstract
Purpose
The purpose of this paper is to evaluate the mechanical properties of glass fibre reinforced epoxy composites modified with amine‐terminated poly (ethylene glycol) benzoate (ATPEGB) along with their thermal stability.
Design/methodology/approach
ATPEGB prepared from poly (ethylene glycol) (PEG) of different molecular weights (200, 400, 600, 4,000 and 20,000) were used as modifiers for glass fibre epoxy composite here. For toughening, 12.5 parts per hundred grams (phr) of epoxy resin of each ATPEGB was added to epoxy and pre‐reacted with it. The impact, tensile and flexural strengths of modified and unmodified composite were characterised and compared for each ATPEGB.
Findings
Modified resin displayed a significant improvement in fracture toughness with glass fibre over unmodified epoxy. The modification caused the formation of oligomer domains having relatively round shapes in the matrix. These oligomer domains led to improved strength and toughness due mainly to the “rubber toughening” effect in the brittle epoxy matrix. The optimum results were obtained for composite modified with ATPEGB‐2 prepared from PEG of molecular weight 400.
Research limitations/implications
In the present context, only 12.5 phr concentration of each ATPEGB was used to modify composite and the composites were made sing three layers of glass fibre. Besides, modification could also be done using other concentrations and more layers of glass fibre could also be used to make composite.
Originality/value
The method for enhancing toughness of epoxy glass fibre composite was novel and finds numerous applications as surface coatings, casting and adhesive onto an intricate structure, etc.
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M.P. Jenarthanan, A. Lakshman Prakash and R. Jeyapaul
This paper aims to develop a mathematical model for analysing surface roughness during end milling by using response surface methodology (RSM) and to determine how the input…
Abstract
Purpose
This paper aims to develop a mathematical model for analysing surface roughness during end milling by using response surface methodology (RSM) and to determine how the input parameters (cutting speed, depth of cut and feed rate) influence the output parameter (surface roughness) in the machining of hybrid glass fibre reinforced plastic (GFRP; Abaca and Glass) composite by using solid carbide end mill cutter.
Design/methodology/approach
Three factors and a three-level Box–Behnken design in RSM were used to carry out the experimental investigation. Handysurf E-35A was used to measure the surface roughness of the machined hybrid GFRP composites. The “Design Expert 8.0” was used to analyse the data collected graphically. Analysis of variance was carried out to validate the model and determine the most significant parameter.
Findings
The response surface model was used to predict the input factors influencing the surface roughness of the machined surfaces of hybrid GFRP composite at different cutting conditions with a chosen range of 95 per cent confidence intervals. Analysis of the influences of the entire individual input machining parameters on the surface roughness carried out using RSM.
Originality/value
The effect of the milling of hybrid GFRP composite on the surface roughness with solid carbide end mill by using RSM has not been analysed yet.
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M.P. Jenarthanan, A. Lakshman Prakash and R. Jeyapaul
This paper aims to develop a mathematical model for delamination during end milling by using response surface methodology (RSM) and to determine how the input parameters (cutting…
Abstract
Purpose
This paper aims to develop a mathematical model for delamination during end milling by using response surface methodology (RSM) and to determine how the input parameters (cutting speed, depth of cut and feed rate) influence the output response (delamination) in machining of hybrid glass fibre reinforced plastic (GFRP; abaca and glass) composite using solid carbide end mill cutter.
Design/methodology/approach
Three factors, three levels Box–Behnken design in RSM is used to carry out the experimental investigation. Shop microscope Mitutoyo TM-500 is used to measure the width of maximum damage of the machined hybrid GFRP composites. The “Design Expert 8.0” is used to analyse the data collected graphically. Analysis of variance is carried out to validate the model and for determining the most significant parameter.
Findings
The RSM is used to predict the input factors influencing the delamination on the machined surfaces of hybrid GFRP composite at different cutting conditions with the chosen range of 95 per cent confidence intervals. Analysis on the influences of the entire individual input machining parameters on the delamination has been carried out using RSM.
Originality/value
Effect of milling of hybrid GFRP composite on delamination with solid carbide end mill has not been analysed yet using RSM.
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Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or…
Abstract
Purpose
Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.
Design/methodology/approach
The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.
Findings
Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.
Originality/value
This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.
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Jenarthanan Mugundhu, R. Jeyapaul and Naresh Neeli
The purpose of this paper is to develop a mathematical model for delamination through response surface methodology (RSM) and analyse the influences of the entire individual input…
Abstract
Purpose
The purpose of this paper is to develop a mathematical model for delamination through response surface methodology (RSM) and analyse the influences of the entire individual input machining parameters (cutting speed, depth of cut and feed rate) on the responses in milling of glass fibre reinforced plastics (GFRP) composites with solid carbide end mill cutter coated with polycrystalline diamond (PCD).
Design/methodology/approach
Three factors, three levels face-centered central composite design matrix in RSM is employed to carry out the experimental investigation. Shop microscope is used to examine the delamination of GFRP composites. The “Design Expert 8.0” software was used for regression and graphical analysis of the data collected. Analysis of variance is used to check the validity of the model and for finding the significant parameters.
Findings
The developed second-order response surface model is used to calculate the delamination of the machined surfaces at different cutting conditions with the chosen range of 95 per cent confidence intervals. Analysis of the influences of the entire individual input machining parameters on the delamination has been carried out using RSM.
Originality/value
Influence of solid carbide end mill coated with PCD on delamination of bi-directional GFRP composite during milling has not been analysed yet using RSM.
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