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Sample records for fibre reinforced epoxy

  1. THERMOMECHANICAL PROPERTIES OF JUTE/BAGASSE HYBRID FIBRE REINFORCED EPOXY THERMOSET COMPOSITES

    OpenAIRE

    Sudhir Kumar Saw; Chandan Datta

    2009-01-01

    Natural fibres are partly replacing currently used synthetic fibres as reinforcement for polymer composites. Jute fibre bundles were high-cellulose-content modified by alkali treatment, while the bagasse fibre bundles were modified by creating quinones in the lignin portions of fibre surfaces and reacting them with furfuryl alcohol (FA) to increase their adhesiveness. The effects of different fibre bundle loading and modification of bagasse fibre surfaces in hybrid fibre reinforced epoxy comp...

  2. Investigation of Thermal Behavior for Natural Fibres Reinforced Epoxy using Thermogravimetric and Differential Scanning Calorimetric Analysis

    Directory of Open Access Journals (Sweden)

    Fauzi F.A.

    2016-01-01

    Full Text Available This paper presented the research works on the investigation of the thermal behavior of the natural fibres; i.e. pineapple leaf fibre, kenaf fibre and mengkuang fibres reinforced epoxy. The thermogravimetric analysis and differential scanning calorimetric analysis were used to measure the thermal behavior of the treated and untreated pineapple, kenaf and mengkuang fibres reinforced epoxy. The samples for both analysis were subjected to maximum temperature 600°C at the heating rate of 10°C/min. The results showed that the treated fibres show higher maximum peak temperature as compared to the untreated fibres. Additionally, the glass transition temperature showed a lower value for all treated fibre. It can be concluded that investigation of thermal properties of these natural fibres could improve the utilization of natural fibre composites in various applications i.e. sports applications.

  3. Tensile properties of compressed moulded Napier/glass fibre reinforced epoxy composites

    Science.gov (United States)

    Fatinah, T. S.; Majid, M. S. Abdul; Ridzuan, M. J. M.; Hong, T. W.; Amin, N. A. M.; Afendi, M.

    2017-10-01

    This paper describes the experimental investigation of the tensile properties of compressed moulded Napier grass fibres reinforced epoxy composites. The effect of treatment 5% sodium hydroxide (NaOH) concentrated solution and hybridization of Napier with CSM E-glass fibres on tensile properties was also studied. The untreated and treated Napier fibres with 25% fibre loading were fabricated with epoxy resin by a cold press process. 7% fibre loading of CSM glass fibre was hybrid as the skin layer for 18% fibre loading of untreated Napier grass fibre. The tensile tests were conducted using Universal Testing Machine in accordance with ASTM D638. The tensile properties of the untreated Napier/epoxy composites were compared with treated Napier/epoxy and untreated Napier/CSM/epoxy composites. The results demonstrated that the tensile performance of untreated Napier fibre composites was significantly improved by both of the modification; alkali treatment and glass fibre hybridization. Napier grass fibres showed promising potentials to be used as reinforcement in the polymer based composites.

  4. Mechanical properties of short random oil palm fibre reinforced epoxy composites

    International Nuclear Information System (INIS)

    Mohd Zuhri Mohamed Yusoff; Mohd Sapuan Salit; Napsiah Ismail; Riza Wirawan

    2010-01-01

    This paper presents the study of mechanical properties of short random oil palm fibre reinforced epoxy (OPF/epoxy) composites. Empty fruit bunch (EFB) was selected as the fibre and epoxy as the matrix. Composite plate with four different volume fractions of oil palm fibre was fabricated, (5 vol %, 10 vol %, 15 vol % and 20 vol %). The fabrication was made by hand-lay up techniques. The tensile and flexural properties showed a decreasing trend as the fibre loading was increased. The highest tensile properties was obtained for the composite with fibre loading of 5 vol % and there were no significant effect for addition of more than 5 vol % to the flexural properties. Interaction between fibre and matrix was observed from the scanning electron microscope (SEM) micrograph. (author)

  5. Mechanical properties of woven banana fibre reinforced epoxy composites

    International Nuclear Information System (INIS)

    Sapuan, S.M.; Leenie, A.; Harimi, M.; Beng, Y.K.

    2006-01-01

    In this paper, the experiments of tensile and flexural (three-point bending) tests were carried out using natural fibre with composite materials (Musaceae/epoxy). Three samples prepared from woven banana fibre composites of different geometries were used in this research. From the results obtained, it was found that the maximum value of stress in x-direction is 14.14 MN/m 2 , meanwhile the maximum value of stress in y-direction is 3.398 MN/m 2 . For the Young's modulus, the value of 0.976 GN/m 2 in x-direction and 0.863 GN/m 2 in y-direction were computed. As for the case of three-point bending (flexural), the maximum load applied is 36.25 N to get the deflection of woven banana fibre specimen beam of 0.5 mm. The maximum stress and Young's modulus in x-direction was recorded to be 26.181 MN/m 2 and 2.685 GN/m 2 , respectively. Statistical analysis using ANOVA-one way has showed that the differences of results obtained from those three samples are not significant, which confirm a very stable mechanical behaviour of the composites under different tests. This shows the importance of this product and allows many researchers to develop an adequate system for producing a good quality of woven banana fibre composite which maybe used for household utilities

  6. Mechanical Property Analysis on Sandwich Structured Hybrid Composite Made from Natural Fibre, Glass Fibre and Ceramic Fibre Wool Reinforced with Epoxy Resin

    Science.gov (United States)

    Bharat, K. R.; Abhishek, S.; Palanikumar, K.

    2017-06-01

    Natural fibre composites find wide range of applications and usage in the automobile and manufacturing industries. They find lack in desired properties, which are required for present applications. In current scenario, many developments in composite materials involve the synthesis of Hybrid composite materials to overcome some of the lacking properties. In this present investigation, two sandwich structured hybrid composite materials have been made by reinforcing Aloe Vera-Ceramic Fibre Wool-Glass fibre with Epoxy resin matrix and Sisal fibre-Ceramic Fibre Wool-Glass fibre with Epoxy resin matrix and its mechanical properties such as Tensile, Flexural and Impact are tested and analyzed. The test results from the two samples are compared and the results show that sisal fibre reinforced hybrid composite has better mechanical properties than aloe vera reinforced hybrid composite.

  7. FLEXURAL PROPERTIES OF ALKALINE TREATED SUGAR PALM FIBRE REINFORCED EPOXY COMPOSITES

    Directory of Open Access Journals (Sweden)

    D. Bachtiar

    2010-06-01

    Full Text Available A study of the effect of alkaline treatment on the flexural properties of sugar palm fibre reinforced epoxy composites is presented in this paper. The composites were reinforced with 10% weight fraction of the fibres. The fibres were treated using sodium hydroxide (NaOH with 0.25 M and 0.5 M concentration solution for 1 hour, 4 hours and 8 hours soaking time. The purpose of treating fibres with alkali was to enhance the interfacial bonding between matrix and fibre surfaces. The maximum flexural strength occurred at 0.25 M NaOH solution with 1 hour of soaking time, i.e 96.71 MPa, improving by 24.41% from untreated fibre composite. But, the maximum flexural modulus took place at 0.5 M NaOH solution with 4 hours soaking time, i.e. 6948 MPa, improving by 148% from untreated composite.

  8. Influence of alkali treatment and fibre length on mechanical properties of short Agave fibre reinforced epoxy composites

    International Nuclear Information System (INIS)

    Mylsamy, K.; Rajendran, I.

    2011-01-01

    Highlights: → New renewable and biodegradable Agave americana fibre. → The mechanical properties of alkali treated composites increase 10-15% to compare untreated composites. → The influence fibre length is contributing the strength of short fibre composites. → Future scope in light weight materials manufacture. -- Abstract: Composites based on short Agave fibres (untreated and alkali treated) reinforced epoxy resin using three different fibre lengths (3 mm, 7 mm and 10 mm length) are prepared by using hand lay up and compression mould technique. The materials were characterized in terms of tensile, compressive, flexural, impact, water absorption properties and machinability behaviour. All mechanical tests showed that alkali treated fibre composites withstand more fracture strain than untreated fibre composites. As evidenced by the dynamic mechanical analysis (DMA) tests, the thermo-mechanical properties of the composite with alkali treated Agave fibre were considerably good as alkali treatment had facilitated more sites of fibre resin interface. The machinability and atomic force microscope (AFM) studies were carried out to analyze the fibre-matrix interaction in untreated and alkali treated Agave fibre-epoxy composites.

  9. Mechanical, thermal and microstructural characteristics of cellulose fibre reinforced epoxy/organoclay nanocomposites

    KAUST Repository

    Alamri, H.

    2012-10-01

    Epoxy nanocomposites reinforced with recycled cellulose fibres (RCFs) and organoclay platelets (30B) have been fabricated and investigated in terms of WAXS, TEM, mechanical properties and TGA. Results indicated that mechanical properties generally increased as a result of the addition of nanoclay into the epoxy matrix. The presence of RCF significantly enhanced flexural strength, fracture toughness, impact strength and impact toughness of the composites. However, the inclusion of 1 wt.% clay into RCF/epoxy composites considerably increased the impact strength and toughness. The presence of either nanoclay or RCF accelerated the thermal degradation of neat epoxy, but at high temperature, thermal stability was enhanced with increased char residue over neat resin. The failure micromechanisms and energy dissipative processes in these nanocomposites were discussed in terms of microstructural observations. © 2012 Published by Elsevier Ltd. All rights reserved.

  10. Morphology and Properties of Geopolymer Coatings on Glass Fibre-Reinforced Epoxy (GRE) pipe

    OpenAIRE

    Shahedan Noor Fifinatasha; Abdullah Mohd Mustafa Al Bakri; Ghazali Che Mohd Ruzaidi; Binhussain Mohammed; Al Husaini Mohammed; Hussin Kamarudin; Ramasamy Shamala

    2016-01-01

    Geopolymer coatings were coated on glass fibre-reinforced epoxy (GRE) pipe by using kaolin, white clay and silica sand as source materials and sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as alkaline solution. The microstructure and mechanical property of geopolymer coating on GRE pipe were methodically investigated through morphology analysis, and flexural strength test. The result indicates the microstructure and interfacial layer between geopolymer coating and GRE pipe significant...

  11. The mechanical properties, deformation and thermomechanical properties of alkali treated and untreated Agave continuous fibre reinforced epoxy composites

    International Nuclear Information System (INIS)

    Mylsamy, K.; Rajendran, I.

    2011-01-01

    Research highlights: → New renewable and biodegradable Agave americana fibre. → Environmentally free materials. → Good mechanical properties of Agave fibre reinforced epoxy composite materials. → Surface modification of the fibre (Alkali treatment) imported good mechanical properties. → Future scope in light weight materials manufacture. -- Abstract: The mechanical properties such as tensile, compressive, flexural, impact strength and water absorption of the alkali treated continuous Agave fibre reinforced epoxy composite (TCEC) and untreated continuous Agave fibre reinforced epoxy composite (UTCEC) were analysed. A comparison of the surfaces of TCEC and UTCEC composites was carried out by dynamic mechanical analysis (DMA), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The thermomechanical properties of the composite reinforced with sodium hydroxide (NaOH) treated Agave fibres were considerably good as the shrinkage of the fibre during alkali treatment had facilitated more points of fibre resin interface. The SEM micrograph and FTIR spectra of the impact fracture surfaces of TCEC clearly demonstrate the better interfacial adhesion between fibre and the matrix. In both analyses the TCEC gave good performance than UTCEC and, thus, there is a scope for its application in light weight manufacture in future.

  12. Morphology and Properties of Geopolymer Coatings on Glass Fibre-Reinforced Epoxy (GRE pipe

    Directory of Open Access Journals (Sweden)

    Shahedan Noor Fifinatasha

    2016-01-01

    Full Text Available Geopolymer coatings were coated on glass fibre-reinforced epoxy (GRE pipe by using kaolin, white clay and silica sand as source materials and sodium hydroxide (NaOH and sodium silicate (Na2SiO3 as alkaline solution. The microstructure and mechanical property of geopolymer coating on GRE pipe were methodically investigated through morphology analysis, and flexural strength test. The result indicates the microstructure and interfacial layer between geopolymer coating and GRE pipe significantly influence the mechanical property of geopolymer coating. However, different source materials gave different microstructure and property in geopolymer coating.

  13. Shape memory performance of asymmetrically reinforced epoxy/carbon fibre fabric composites in flexure

    Directory of Open Access Journals (Sweden)

    M. Fejos

    2013-06-01

    Full Text Available In this study asymmetrically reinforced epoxy (EP/carbon fibre (CF fabric composites were prepared and their shape memory properties were quantified in both unconstrained and fully constrained flexural tests performed in a dynamic mechanical analyser (DMA. Asymmetric layering was achieved by incorporating two and four CF fabric layers whereby setting a resin- and reinforcement-rich layer ratio of 1/4 and 1/2, respectively. The recovery stress was markedly increased with increasing CF content. The related stress was always higher when the CF-rich layer experienced tension load locally. Specimens with CF-rich layers on the tension side yielded better shape fixity ratio, than those with reinforcement layering on the compression side. Cyclic unconstrained shape memory tests were also run up to five cycles on specimens having the CF-rich layer under local tension. This resulted in marginal changes in the shape fixity and recovery ratios.

  14. Effect of water absorption on the mechanical properties of nanoclay filled recycled cellulose fibre reinforced epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.

    2013-01-01

    Recycled cellulose fibre (RCF) reinforced epoxy/clay nanocomposites were successfully synthesized with different weight percentages (0%, 1%, 3% and 5%) of organoclay platelets (30B). The objective of this study was to investigate the effect of water absorption on the physical and mechanical properties of the RCF reinforced epoxy/clay nanocomposites. TEM images indicated a well-intercalated structure of nanoclay/epoxy matrix with some exfoliated regions. Water absorption was found to decrease as the clay content increased. The flexural strength, flexural modulus and fracture toughness significantly decreased as a result of water absorption. However, the properties of impact strength and impact toughness were found to increase after exposing to water. The addition of nanoclay slightly minimized the effect of moisture on the mechanical properties. SEM images showed that water absorption severely damaged the cellulose fibres and the bonding at fibres-matrix interfaces in wet composites. © 2012 Elsevier Ltd. All rights reserved.

  15. Tensile and Flexural Properties of Chopped Strand E-glass Fibre Mat Reinforced CNSL-Epoxy Composites.

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    Nayak Suhas Yeshwant

    2018-01-01

    Full Text Available Glass fibres have the principal advantages such as high tensile strength, high chemical resistance, low cost, and excellent insulating properties which makes them an important constituent in fibre reinforced plastic and composite industry. In this study, E-glass fibre in the form of Chopped Strand Mat (CSM with different weight fractions such as 15%, 30%, and 45% were used as reinforcement in CNSL-epoxy resin composites. Fabrication of the composites was done by hand layup technique. Micro-hardness, tensile and flexural properties were investigated for all the composite panels of different compositions. The results clearly indicated an improvement in micro hardness, tensile and flexural properties with the increase in fibre content.

  16. Thermo-Mechanical Behaviour of Flax-Fibre Reinforced Epoxy Laminates for Industrial Applications

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    Giuseppe Pitarresi

    2015-11-01

    Full Text Available The present work describes the experimental mechanical characterisation of a natural flax fibre reinforced epoxy polymer composite. A commercial plain woven quasi-unidirectional flax fabric with spun-twisted yarns is employed in particular, as well as unidirectional composite panels manufactured with three techniques: hand-lay-up, vacuum bagging and resin infusion. The stiffness and strength behaviours are investigated under both monotonic and low-cycle fatigue loadings. The analysed material has, in particular, shown a typical bilinear behaviour under pure traction, with a knee yield point occurring at a rather low stress value, after which the material tensile stiffness is significantly reduced. In the present work, such a mechanism is investigated by a phenomenological approach, performing periodical loading/unloading cycles, and repeating tensile tests on previously “yielded” samples to assess the evolution of stiffness behaviour. Infrared thermography is also employed to measure the temperature of specimens during monotonic and cyclic loading. In the first case, the thermal signal is monitored to correlate departures from the thermoelastic behaviour with the onset of energy loss mechanisms. In the case of cyclic loading, the thermoelastic signal and the second harmonic component are both determined in order to investigate the extent of elastic behaviour of the material.

  17. Three-body abrasion on wear and frictional performance of treated betelnut fibre reinforced epoxy (T-BFRE) composite

    International Nuclear Information System (INIS)

    Yousif, B.F.; Nirmal, Umar; Wong, K.J.

    2010-01-01

    This work aims to investigate the wear and frictional behaviour of a new epoxy composite based on treated betelnut fibres subjected to three-body abrasion using different abrasive particle sizes (500 μm, 714 μm and 1430 μm) and sliding velocities (0.026-0.115 m s -1 ) at constant applied load (5 N) using a newly developed Linear Tribo Machine. The worn surfaces of the composite were studied using scanning electron microscope. The work revealed that the predominant wear mechanism of treated betelnut fibre reinforced epoxy (T-BFRE) composite sliding against grain sands was plastic deformation, pitting and pullout of betelnut fibres. The composite exhibited higher values in frictional coefficient when it was subjected against coarse sand. Besides, the abrasive wear of the composite is depending on the size of abrasive particles and sliding velocity. Higher weight loss is noticed at high sliding velocities. The specific wear rate for the composite subjected to three different sand particles follow the order of: coarse > grain > fine sands respectively.

  18. sisal fibre- epoxy compos

    African Journals Online (AJOL)

    eobe

    2015-10-04

    Oct 4, 2015 ... 2, 4 PHYSICS ADVANCED LABORATORY, SHEDA SCIENCE AND TECHNOLOGY COMPLEX, SHEDA, ABUJA FCT NIGERIA. 3NUCLEAR .... [33]. However, polyesters, vinyl ester and other thermosetting resins can also be used for fiber reinforced composite materials. The choice of epoxy matrix in this ...

  19. Interface Bond Improvement of Sisal Fibre Reinforced Polylactide Composites with Added Epoxy Oligomer.

    Science.gov (United States)

    Hao, Mingyang; Wu, Hongwu; Qiu, Feng; Wang, Xiwen

    2018-03-07

    To improve the interfacial bonding of sisal fiber-reinforced polylactide biocomposites, polylactide (PLA) and sisal fibers (SF) were melt-blended to fabricate bio-based composites via in situ reactive interfacial compatibilization with addition of a commercial grade epoxy-functionalized oligomer Joncryl ADR @ -4368 (ADR). The FTIR (Fourier Transform infrared spectroscopy) analysis and SEM (scanning electron microscope) characterization demonstrated that the PLA molecular chain was bonded to the fiber surface and the epoxy-functionalized oligomer played a hinge-like role between the sisal fibers and the PLA matrix, which resulted in improved interfacial adhesion between the fibers and the PLA matrix. The interfacial reaction and microstructures of composites were further investigated by thermal and rheological analyses, which indicated that the mobility of the PLA molecular chain in composites was restricted because of the introduction of the ADR oligomer, which in turn reflected the improved interfacial interaction between SF and the PLA matrix. These results were further justified with the calculation of activation energies of glass transition relaxation (∆ E a ) by dynamic mechanical analysis. The mechanical properties of PLA/SF composites were simultaneously reinforced and toughened with the addition of ADR oligomer. The interfacial interaction and structure-properties relationship of the composites are the key points of this study.

  20. Interface Bond Improvement of Sisal Fibre Reinforced Polylactide Composites with Added Epoxy Oligomer

    Directory of Open Access Journals (Sweden)

    Mingyang Hao

    2018-03-01

    Full Text Available To improve the interfacial bonding of sisal fiber-reinforced polylactide biocomposites, polylactide (PLA and sisal fibers (SF were melt-blended to fabricate bio-based composites via in situ reactive interfacial compatibilization with addition of a commercial grade epoxy-functionalized oligomer Joncryl ADR@-4368 (ADR. The FTIR (Fourier Transform infrared spectroscopy analysis and SEM (scanning electron microscope characterization demonstrated that the PLA molecular chain was bonded to the fiber surface and the epoxy-functionalized oligomer played a hinge-like role between the sisal fibers and the PLA matrix, which resulted in improved interfacial adhesion between the fibers and the PLA matrix. The interfacial reaction and microstructures of composites were further investigated by thermal and rheological analyses, which indicated that the mobility of the PLA molecular chain in composites was restricted because of the introduction of the ADR oligomer, which in turn reflected the improved interfacial interaction between SF and the PLA matrix. These results were further justified with the calculation of activation energies of glass transition relaxation (∆Ea by dynamic mechanical analysis. The mechanical properties of PLA/SF composites were simultaneously reinforced and toughened with the addition of ADR oligomer. The interfacial interaction and structure–properties relationship of the composites are the key points of this study.

  1. Morphology and contact angle studies of poly(styrene-co-acrylonitrile modified epoxy resin blends and their glass fibre reinforced composites

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available In this study, the surface characteristics of blends and composites of epoxy resin were investigated. Poly(styrene-co-acylonitrile (SAN was used to modify diglycedyl ether of bisphenol-A (DGEBA type epoxy resin cured with diamino diphenyl sulfone (DDS and the modified epoxy resin was used as the matrix for fibre reinforced composites (FRP’s. E-glass fibre was used as the fibre reinforcement. The scanning electron micrographs of the fractured surfaces of the blends and composites were analyzed. Morphological analysis revealed different morphologies such as dispersed, cocontinuous and phase-inverted structures for the blends. Contact angle studies were carried out using water and methylene iodide at room temperature. The solid surface energy was calculated using harmonic mean equations. Blending of epoxy resin increases its contact angle. The surface free energy, work of adhesion, interfacial free energy, spreading coefficient and Girifalco-Good’s interaction parameter were changed significantly in the case of blends and composites. The incorporation of thermoplastic and glass fibre reduces the wetting and hydrophilicity of epoxy resin.

  2. Insulation Characteristics of Sisal Fibre/Epoxy Composites

    Directory of Open Access Journals (Sweden)

    A. Shalwan

    2017-01-01

    Full Text Available Using natural fibres in civil engineering is the aim of many industrial and academics sectors to overcome the impact of synthetic fibres on environments. One of the potential applications of natural fibres composites is to be implemented in insulation components. Thermal behaviour of polymer composites based on natural fibres is recent ongoing research. In this article, thermal characteristics of sisal fibre reinforced epoxy composites are evaluated for treated and untreated fibres considering different volume fractions of 0–30%. The results revealed that the increase in the fibre volume fraction increased the insulation performance of the composites for both treated and untreated fibres. More than 200% insulation rate was achieved at the volume fraction of 20% of treated sisal fibres. Untreated fibres showed about 400% insulation rate; however, it is not recommended to use untreated fibres from mechanical point of view. The results indicated that there is potential of using the developed composites for insulation purposes.

  3. The Effects of Thermophysical Properties and Environmental Conditions on Fire Performance of Intumescent Coatings on Glass Fibre-Reinforced Epoxy Composites

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    Baljinder K. Kandola

    2015-08-01

    Full Text Available Intumescent coatings are commonly used as passive fire protection systems for steel structures. The purpose of this work is to explore whether these can also be used effectively on glass fibre-reinforced epoxy (GRE composites, considering the flammability of the composites compared to non-flammable steel substrate. The thermal barrier and reaction-to-fire properties of three commercial intumescent coatings on GRE composites have been studied using a cone calorimeter. Their thermophysical properties in terms of heating rate and/or temperature dependent char expansion ratios and thermal conductivities have been measured and correlated. It has been suggested that these two parameters can be used to design coatings to protect composite laminates of defined thicknesses for specified periods of time. The durability of the coatings to water absorption, peeling, impact, and flexural loading were also studied. A strong adhesion between all types of coatings and the substrate was observed. Water soaking had a little effect on the fire performance of epoxy based coatings. All types of 1 mm thick coatings on GRE helped in retaining ~90% of the flexural property after 2 min exposure to 50 kW/m2 heat flux whereas the uncoated laminate underwent severe delamination and loss in structural integrity after 1 min.

  4. The Effects of Thermophysical Properties and Environmental Conditions on Fire Performance of Intumescent Coatings on Glass Fibre-Reinforced Epoxy Composites.

    Science.gov (United States)

    Kandola, Baljinder K; Luangtriratana, Piyanuch; Duquesne, Sophie; Bourbigot, Serge

    2015-08-11

    Intumescent coatings are commonly used as passive fire protection systems for steel structures. The purpose of this work is to explore whether these can also be used effectively on glass fibre-reinforced epoxy (GRE) composites, considering the flammability of the composites compared to non-flammable steel substrate. The thermal barrier and reaction-to-fire properties of three commercial intumescent coatings on GRE composites have been studied using a cone calorimeter. Their thermophysical properties in terms of heating rate and/or temperature dependent char expansion ratios and thermal conductivities have been measured and correlated. It has been suggested that these two parameters can be used to design coatings to protect composite laminates of defined thicknesses for specified periods of time. The durability of the coatings to water absorption, peeling, impact, and flexural loading were also studied. A strong adhesion between all types of coatings and the substrate was observed. Water soaking had a little effect on the fire performance of epoxy based coatings. All types of 1 mm thick coatings on GRE helped in retaining ~90% of the flexural property after 2 min exposure to 50 kW/m² heat flux whereas the uncoated laminate underwent severe delamination and loss in structural integrity after 1 min.

  5. The Effect of Customized Woven and Stacked Layer Orientation on Tensile and Flexural Properties of Woven Kenaf Fibre Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    A. Hamdan

    2016-01-01

    Full Text Available The synthetic fibres have created some issues including risk of inhalation during fabrication process, renewability, biodegradability, and recyclability in composites industry. The usage of biocomposites as a replacement to synthetic fibres is beginning to be widespread. However, it is noted that lesser attention has been devoted to evaluating the mechanical properties of woven kenaf composites at various woven and stacked layer orientation. Thus, the research objective is to identify the effect of woven and stacked layer orientation on tensile and flexural properties of kenaf composites. Two types of fibre orientation are employed; type A contains a higher yarn density and type B contains a low yarn density. The tensile and flexural tests are conducted to analyze the mechanical properties of woven kenaf fibre composites and compare them to random chopped kenaf composites. The fracture interface between fibre and matrix epoxy is further investigated via scanning electron microscope. Type A kenaf improved up to 199% and 177% as compared to random chopped kenaf for flexural strength and tensile strength, respectively. Scanning electron microscopy analysis shows that resin matrix is properly induced into kenaf fibre gap hence giving additional strength to woven kenaf as compared to random chopped kenaf.

  6. Thermal conductivity behavior of oil palm/jute fibre-reinforced hybrid composites

    Science.gov (United States)

    Jawaid, M.; Saba, N.; Alothman, Othman Y.; Khalil, H. P. S. Abdul; Mariatti, M.

    2017-12-01

    In this study epoxy matrix, oil palm empty fruit bunch (EFB) fibres, jute fibres and oil palm EFB/jute fibre reinforced epoxy hybrid composites in different layering pattern at EFB: jute ratio (50:50) fabricated by hand lay-up technique. The thermal conductivity of epoxy matrix, oil palm EFB, jute and oil palm EFB/jute hybrid reinforced epoxy composites has been evaluated by Hot Disk Thermal Constants Analyser (Hot Disk TPS2500 S) equipped with Hot Disk Analysis Software version 5.9. Obtained results indicated that thermal conductivity of epoxy matrix increased with reinforcing of oil palm EFB and jute fibres. Hybridization of oil palm EFB with jute fibres allows an increased in thermal conductivity of oil palm EFB/jute hybrid composites. We concluded that oil palm EFB/jute hybrid composites can be used for thermal applications in automotive and construction industry to save energy.

  7. Electron beam irradiation in natural fibres reinforced polymers (NFRP)

    Energy Technology Data Exchange (ETDEWEB)

    Kechaou, B. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Salvia, M. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Fakhfakh, Z. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); Juve, D. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Boufi, S. [LSME-Faculte des Sciences de Sfax, 3018 Sfax (Tunisia); Kallel, A. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); Treheux, D. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France)], E-mail: daniel.treheux@ec-lyon.fr

    2008-11-15

    This study focuses on the electric charge motion in unsatured polyester and epoxy composites reinforced by natural fibres of Alfa type, treated by different coupling agents. The electric charging phenomenon is studied by scanning electron microscopy mirror effect (SEMME) coupled with the induced current method (ICM). Previously, using the same approach, glass fibre reinforced epoxy (GFRE) was studied to correlate mechanical [B. Kchaou, C. Turki, M. Salvia, Z. Fakhfakh, D. Treheux, Composites Science and Technology 64 (2004) 1467], or tribological [B. Kchaou, C. Turki, M. Salvia, Z. Fakhfakh, D. Treheux, Dielectric and friction behaviour of unidirectionalglass fibre reinforced epoxy (GFRE), Wear, 265 (2008) 763.] properties and dielectric properties. It was shown that the dielectric properties of the fibre-matrix interfaces play a significant role in the optimization of the composite. This result seems to be the same for natural fibre composites: the fibre-matrix interfaces allow a diffusion of the electric charges which can delocalize the polarization energy and consequently delay the damage of the composite. However, a non-suited sizing can lead to a new trapping of electric charges along these same interfaces with, as a consequence, a localization of the polarisation energy. The optimum composite is obtained for one sizing which helps, at the same time, to have a strong fibre-matrix adhesion and an easy flow of the electric charges along the interface.

  8. Plasma treatment of carbon fibres and glass-fibre-reinforced polyesters at atmospheric pressure for adhesion improvement

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Løgstrup Andersen, Tom; Toftegaard, Helmuth Langmaack

    2014-01-01

    composites before assembling them to build wind turbine blades. In the present work, unsized carbon fibres are continuously treated using a dielectric barrier discharge plasma in helium at atmospheric pressure, and carbon fibre reinforced epoxy composite plates are manufactured for the mechanical test....... The plasma treatment improved fracture toughness, indicating that adhesion between the fibres and the epoxy was enhanced by the treatment. In addition, glass-fibre-reinforced polyester plates are treated using a gliding arc and an ultrasound enhanced dielectric barrier discharge, improving the wettability...... and/or the adhesive strength with a vinylester resin....

  9. Continuous jute fibre reinforced laminated paper composite

    Indian Academy of Sciences (India)

    Plastic bags create a serious environmental problem. The proposed jute fibre reinforced laminated paper composite and reinforcement-fibre free paper laminate may help to combat the war against this pollutant to certain extent. The paper laminate, without reinforcement fibre, exhibited a few fold superiority in tensile ...

  10. Plasma treatment of carbon fibres and glass-fibre-reinforced polyesters at atmospheric pressure for adhesion improvement

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Løgstrup Andersen, Tom; Toftegaard, Helmuth Langmaack

    2014-01-01

    Atmospheric pressure plasma treatment is useful for adhesion improvement, because cleaning, roughening and addition of polar functional groups can be expected at the surfaces. Its possible applications in the wind energy industry include plasma treatment of fibres and fibre-reinforced polymer....... The plasma treatment improved fracture toughness, indicating that adhesion between the fibres and the epoxy was enhanced by the treatment. In addition, glass-fibre-reinforced polyester plates are treated using a gliding arc and an ultrasound enhanced dielectric barrier discharge, improving the wettability...... composites before assembling them to build wind turbine blades. In the present work, unsized carbon fibres are continuously treated using a dielectric barrier discharge plasma in helium at atmospheric pressure, and carbon fibre reinforced epoxy composite plates are manufactured for the mechanical test...

  11. Experimental study of bamboo using banana and linen fibre reinforced polymeric composites

    Directory of Open Access Journals (Sweden)

    Ramachandran M.

    2016-09-01

    Full Text Available The application of natural fibres such as bamboo, jute, banana, coir, linen and the like in Fibre Reinforced Polymeric (FRP composites have become so vital due to their high effective stiffness and strength, availability, low cost, specific strength, better dimensional stability and mechanical properties, eco-friendly and biodegradable as compared with synthetic fibres. The interest in natural fibre reinforced polymeric composites is rapidly springing up in terms of research and industrial applications. The increased applications of these natural fibres in such composites are a proof to this claim. The paper deals with the detailed study of bamboo fibre, banana fibre and linen fibre cut into 2−4 mm of length with epoxy resin having random orientations. Various tests like Impact test (IZOD and CHARPY test, Fourier Transform Infra-Red (FTIR test and Rockwell Hardness test were conducted on 10 specimens of bamboo epoxy resin composite, bamboo−banana epoxy resin composite and bamboo−linen epoxy resin composite. It is analysed and proved that bamboo−banana epoxy resin composite shows better results in Impact test with values of 4 Joules for Izod test and 5 Joules for Charpy test and in FTIR test, compatibility of fibres with polymers in bamboo−banana epoxy resin composite are the best while bamboo−linen epoxy resin composite shows better result in Rockwell hardness test with value of 40 RHN.

  12. Epoxy-based carbon nanotubes reinforced composites

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2011-04-01

    Full Text Available developed strategy offering promising results is to reinforce epoxy matrices with nano-sized organic and inorganic particles such as carbon nanotubes (CNTs), carbon nanofibres (CNFs), nanoclays, metal oxide nanoparticles, etc. and make new materials...

  13. Modified glass fibre reinforced polymer composites

    Science.gov (United States)

    Cao, Yumei

    traditional and modern techniques at the same time, the newly developed modified glass fibre reinforced epoxy matrix composites (MGFRECs) have much improved comprehensive properties. The flexural strength, the flexural modulus, the shear modulus and the impact energy (Izod impact test) of the composites were improved up to 87%, 74%, 30% and 89% respectively when modified samples were compared to the samples made by the traditional methods.

  14. Degradation Behavior of Epoxy Resins in Fibre Metal Laminates Under Thermal Conditions

    NARCIS (Netherlands)

    Zhu, G.; Xiao, Y.; Yang, Y.; Wang, J.; Sun, B.; Boom, R.

    2012-01-01

    GLARE (glass fibre/epoxy reinforced aluminum laminate) is a member of the fiber metal laminate (FML) family, and is built up of alternating metal and fiber layers. About 500m2 GLARE is employed in each Airbus A380 because of the superior mechanical properties over the monolithic aluminum alloys,

  15. Concretes reinforced with acrylic fibres

    Directory of Open Access Journals (Sweden)

    Amat, T.

    1997-12-01

    Full Text Available This article is based on works, carried out at the IETcc, aimed to evaluate the behaviour of concretes reinforced with acrylic polyacrylonitrile fibres, and to study the influence they have on concrete physical and mechanical properties.

    El presente artículo está basado en trabajos realizados en el Instituto de Ciencias de la Construcción Eduardo Torroja, teniendo por objetivo evaluar el comportamiento de los hormigones reforzados con fibras acrílicas de poliacrilonitrilo, estudiando la influencia que tiene sobre sus propiedades físicas y mecánicas.

  16. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    Durability studies are carried out at BKM as part of the research project "Design Methods for Fibre Reinforced Concrete" (FRC) involving BKM, The Concrete Research Center at DTI, Building Technology at Aalborg University, Rambøll, 4K-Beton and Rasmussen & Schiøtz. Concrete beams with or without...... fibre reinforcement are exposed to a combination of mechanical and environmental load to indicate whether fibre reinforcement will improve the durability of cracked concrete structures. Secondly, it is the aim to identify important mechanisms for the effect of the fibre reinforcement on the durability......) and polypropylene fibres (PP) are used in the concrete beams as well as main reinforcement. Results of the durability tests on cracked FRC-beams are compared with results for uncracked FRC-beams and beams without fibres....

  17. Durability of fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Hansen, Kurt Kielsgaard

    1996-01-01

    The planned research will indicate, whether fibre reinforced concrete has better or worse durability than normal concrete. Durability specimens will be measured on cracked as well as uncracked specimens. Also the pore structure in the concrete will be characterized.Keywords: Fibre reinforced...... concrete, durability, pore structure, mechanical load...

  18. Fundamentals of fibre-reinforced soil engineering

    CERN Document Server

    Shukla, Sanjay Kumar

    2017-01-01

    This book is intended to serve as a one-stop reference on fibre-reinforced soils. Over the past 30-35 years, the engineering behaviour of randomly distributed/oriented fibre-reinforced soil, also called simply fibre-reinforced soil, has been investigated in detail by researchers and engineers worldwide. Waste fibres (plastic waste fibres, old tyre fibres, etc.) create disposal and environmental problems. Utilization of such fibres in construction can help resolve these concerns. Research studies and some field applications have shown that the fibres can be utilized in large quantities in geotechnical and civil engineering applications in a cost-effective and environmentally friendly manner. This book covers a complete description of fibres, their effects when included within a soil or other similar materials such as the fly ash, and their field applications. It gives a detailed view of fibre-reinforced soil engineering. The book will be useful to students, professional, and researchers alike, and can also ser...

  19. Fibre reinforced concrete exposed to elevated temperature

    Science.gov (United States)

    Novák, J.; Kohoutková, A.

    2017-09-01

    Although concrete when subject to fire performs very well, its behaviour and properties change dramatically under high temperature due to damaged microstructure and mesostructure. As fibre reinforced concrete (FRC) represents a complex material composed of various components with different response to high temperature, to determine its behaviour and mechanical properties in fire is a demanding task. The presented paper provides a summary of findings on the fire response of fibre FRC. Namely, the information on steel fibre reinforced concrete (SFRC), synthetic fibre reinforced concrete and hybrid (steel + synthetic) fibre reinforced concrete have been gathered from various contributions published up to date. The mechanical properties including the melting point and ignition point of fibres affect significantly the properties of concrete composites with addition of fibres. The combination of steel and synthetic fibres represents a promising alternative how to ensure good toughness of a concrete composite before heating and improve its residual mechanical behaviour and spalling resistance as well as the ductility after heating. While synthetic fibres increase concrete spalling resistance, steel fibres in a concrete mix leads to an improvement in both mechanical properties and resistance to heating effects.

  20. Electron processing of fibre-reinforced advanced composites

    International Nuclear Information System (INIS)

    Singh, A.; Saunders, C.B.; Barnard, J.W.; Lopata, V.J.; Kremers, W.; McDougall, T.E.; Chung, M.; Tateishi, Miyoko

    1996-01-01

    Advanced composites, such as carbon-fibre-reinforced epoxies, are used in the aircraft, aerospace, sporting goods, and transportation industries. Though thermal curing is the dominant industrial process for advanced composites, electron curing of similar composites containing acrylated epoxy matrices has been demonstrated by our work. The main attraction of electron processing technology over thermal technology is the advantages it offers which include ambient temperature curing, reduced curing times, reduced volatile emissions, better material handling, and reduced costs. Electron curing technology allows for the curing of many types of products, such as complex shaped, those containing different types of fibres and up to 15 cm thick. Our work has been done principally with the AECL's 10 MeV, 1 kW electron accelerator; we have also done some comparative work with an AECL Gammacell 220. In this paper we briefly review our work on the various aspects of electron curing of advanced composites and their properties. (Author)

  1. Fatigue behaviour of uni-directional flax fibre/epoxy composites

    DEFF Research Database (Denmark)

    Ueki, Yosuke; Lilholt, Hans; Madsen, Bo

    2015-01-01

    A study related to the fatigue behaviour of natural fibre-reinforced composites was conducted to expand their range of product applications. A uni-directional flax-epoxy composite was fabricated and several conditions of tension-tension fatigue tests were performed. During fatigue testing......, the composite showed an increase of stiffness, a typical observation for natural fibre-reinforced composites, and this was found to be accompanied by accumulation of residual strain. A clear linear relationship was found between the stiffening effect and the residual strain. In addition, it was revealed...... that the fatigue behaviour was clearly influenced by the frequency of cyclic loading. Lower frequencies induced more significant stiffening and shorter fatigue life. These results suggest that fatigue damaging is progressing simultaneously with the stiffening effect in natural fibre-reinforced composites...

  2. Design Methods for Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Stang, Henrik

    1996-01-01

    The present paper describes the outline of a research project on Fibre Reinforced Concrete (FRC) currently being carried out in Denmark under the supervision of Danish Council of Technology, Danish Technical Research Council and Danish Natural Science Research Counsil.......The present paper describes the outline of a research project on Fibre Reinforced Concrete (FRC) currently being carried out in Denmark under the supervision of Danish Council of Technology, Danish Technical Research Council and Danish Natural Science Research Counsil....

  3. Compressive behaviour of unidirecterional flax fibre reinforced composites

    NARCIS (Netherlands)

    Bos, H.L.; Molenveld, K.; Teunissen, W.; Wingerde, van A.M.; Delft, van D.R.V.

    2004-01-01

    The compressive strength of unidirectional flax fibre epoxy composites was studied. The compressive strength is influenced negatively by the presence of kink bands in the flax fibres. Improvement of the adhesion between the fibres and the epoxy resin can be achieved easily by removing the thin wax

  4. DESIGN OF COMPOSITION OF CONCRETE USING POLYPROPYLENE FIBRE REINFORCEMENT

    OpenAIRE

    Dang Van Thanh1,*, Vu Hoang Hiep2, Nguyen Van Bac1, Hoang Gia Duong1

    2016-01-01

    Fibre-reinforced concrete is an emerging trend that delivers new materials with high quality for construction. Polyporpylene fibre, an organic textile, has high potential to be used for reinforcing concrete, but there has been little research conducted into using this fibre for concrete reinforcement worldwide and no research work on this fibre reinforced concrete has been published in Vietnam. Thereofore, researchinginto Polyporylene fibre reinforced concrete to establish fundamental underst...

  5. Study of flax hybrid preforms reinforced epoxy composites

    International Nuclear Information System (INIS)

    Muralidhar, B. A

    2013-01-01

    Highlights: • We examine the thermal, viscoelastic and mechanical behaviour of flax preform hybrid composites. • The thermal stability of the matrix decrease with increasing volume fraction of flax preforms. • The effect of number of preform layers and the lay-up architecture were studied.. • Morphological study on the fractured surface of the composite laminate is carried out. - Abstracts: This study investigates the thermal, mechanical and thermomechanical properties of flax hybrid preform reinforced epoxy composites. Flax plain weave fabric and 1 × 1 weft rib knitted structures were together used as reinforcements and the composites were produced using hand lay-up technique. Specimen preparation and testing were carried out as per ASTM standards. Thermogravimetric analysis (TGA) indicates a decrease in thermal stability of the matrix polymer with the incorporation of flax hybrid preform. The dynamic mechanical analysis revealed a shift in the T g with the addition of flax hybrid preforms. Mechanical data obtained showed that tensile strength and stiffness is a product of the fibre/matrix synergy, whereas the compressive strength and stiffness are contributed by the reinforcing matrix. Additionally, investigation show that laminate with knitted preform as skin layer exhibits superior mechanical properties. However, improved tensile properties at lower fibre volume fraction, reinforces the opinion that hybrid preform composites can offer significant benefits in terms of performance, weight and overall cost. The failure mechanism was analysed, by scanning electron microscope (SEM)

  6. Recent Development of Flax Fibres and Their Reinforced Composites Based on Different Polymeric Matrices

    Directory of Open Access Journals (Sweden)

    Hrushikesh Abhyankar

    2013-11-01

    Full Text Available This work describes flax fibre reinforced polymeric composites with recent developments. The properties of flax fibres, as well as advanced fibre treatments such as mercerization, silane treatment, acylation, peroxide treatment and coatings for the enhancement of flax/matrix incompatibility are presented. The characteristic properties and characterizations of flax composites on various polymers including polypropylene (PP and polylactic acid, epoxy, bio-epoxy and bio-phenolic resin are discussed. A brief overview is also given on the recent nanotechnology applied in flax composites.

  7. Thermoplastic impact property improvement in hybrid natural fibre epoxy composite bumper beam

    Energy Technology Data Exchange (ETDEWEB)

    Davoodi, M M; Sapuan, S M; Ali, Aidy [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia 43400 UPM Serdang, Selangor (Malaysia); Ahmad, D; Khalina, A, E-mail: makinejadm2@asme.org [Department of Biological and Agricultural Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2010-05-15

    Utilization of thermoset resin as a bumper beam composite matrix is currently more dominated in car manufacturer suppliers, because of availability, easy processing, low material cost and production equipment investment. Moreover, low viscosity, shrinkage and excellent flow facilitate better fibre impregnation and proper surface resin wetting. Three-dimensional cross linking curing increase impact, creep and environmental stress cracking resistance properties. Low impact properties of natural fibre epoxy composite, are main issues in its employment for automotive structural components. Impact properties in epoxy composite bumper beam could be increased by modifying the resin, reinforcement and manufacturing process as well as geometry parameters such as cross section, thickness, added ribs and fixing method optimizations could strengthen impact resistance. There are two main methods, flexibilisation and toughening, as modifying the resin in order to improve the impact properties of epoxy composite, which form single phase or two-phase morphology to make modifier as epoxy or from separate phase to keep the thermo-mechanical properties. Liquid rubber, thermoplastic, core shell particle and rigid particle are different methods of toughening improvements. In this research, thermoplastic toughening has used to improve impact properties in hybrid natural fibre epoxy composite for automotive bumper beam and has achieved reasonable impact improvements.

  8. Thermoplastic impact property improvement in hybrid natural fibre epoxy composite bumper beam

    International Nuclear Information System (INIS)

    Davoodi, M M; Sapuan, S M; Ali, Aidy; Ahmad, D; Khalina, A

    2010-01-01

    Utilization of thermoset resin as a bumper beam composite matrix is currently more dominated in car manufacturer suppliers, because of availability, easy processing, low material cost and production equipment investment. Moreover, low viscosity, shrinkage and excellent flow facilitate better fibre impregnation and proper surface resin wetting. Three-dimensional cross linking curing increase impact, creep and environmental stress cracking resistance properties. Low impact properties of natural fibre epoxy composite, are main issues in its employment for automotive structural components. Impact properties in epoxy composite bumper beam could be increased by modifying the resin, reinforcement and manufacturing process as well as geometry parameters such as cross section, thickness, added ribs and fixing method optimizations could strengthen impact resistance. There are two main methods, flexibilisation and toughening, as modifying the resin in order to improve the impact properties of epoxy composite, which form single phase or two-phase morphology to make modifier as epoxy or from separate phase to keep the thermo-mechanical properties. Liquid rubber, thermoplastic, core shell particle and rigid particle are different methods of toughening improvements. In this research, thermoplastic toughening has used to improve impact properties in hybrid natural fibre epoxy composite for automotive bumper beam and has achieved reasonable impact improvements.

  9. FOAM CONCRETE REINFORCEMENT BY BASALT FIBRES

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2012-10-01

    Full Text Available The authors demonstrate that the foam concrete performance can be improved by dispersed reinforcement, including methods that involve basalt fibres. They address the results of the foam concrete modeling technology and assess the importance of technology-related parameters. Reinforcement efficiency criteria are also provided in the article. Dispersed reinforcement improves the plasticity of the concrete mix and reduces the settlement crack formation rate. Conventional reinforcement that involves metal laths and rods demonstrates its limited application in the production of concrete used for thermal insulation and structural purposes. Dispersed reinforcement is preferable. This technology contemplates the infusion of fibres into porous mixes. Metal, polymeric, basalt and glass fibres are used as reinforcing components. It has been identified that products reinforced by polypropylene fibres demonstrate substantial abradability and deformability rates even under the influence of minor tensile stresses due to the low adhesion strength of polypropylene in the cement matrix. The objective of the research was to develop the type of polypropylene of D500 grade that would demonstrate the operating properties similar to those of Hebel and Ytong polypropylenes. Dispersed reinforcement was performed by the basalt fibre. This project contemplates an autoclave-free technology to optimize the consumption of electricity. Dispersed reinforcement is aimed at the reduction of the block settlement in the course of hardening at early stages of their operation, the improvement of their strength and other operating properties. Reduction in the humidity rate of the mix is based on the plasticizing properties of fibres, as well as the application of the dry mineralization method. Selection of optimal parameters of the process-related technology was performed with the help of G-BAT-2011 Software, developed at Moscow State University of Civil Engineering. The authors also

  10. Life cycle strain monitoring in glass fibre reinforced polymer laminates using embedded fibre Bragg grating sensors from manufacturing to failure

    DEFF Research Database (Denmark)

    Nielsen, Michael Wenani; Schmidt, Jacob Wittrup; Høgh, Jacob Herold

    2013-01-01

    A holistic approach to strain monitoring in fibre-reinforced polymer composites is presented using embedded fibre Bragg grating sensors. Internal strains are monitored in unidirectional E-glass/epoxy laminate beams during vacuum infusion, curing, post-curing and subsequent loading in flexure unti...... Bragg gratings within the loading regime. This study confirms the effectiveness of composite life cycle strain monitoring for developing consistent manufacturing processes....... failure. The internal process-induced strain development is investigated through use of different cure schedules and tool/part interactions. The fibre Bragg grating sensors successfully monitor resin flow front progression during infusion, and strain development during curing, representative...... of the different cure temperatures and tool/part interfaces used. Substantial internal process-induced strains develop in the transverse fibre direction, which should be taken into consideration when designing fibre-reinforced polymer laminates. Flexure tests indicate no significant difference in the mechanical...

  11. Frost resistance of fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1999-01-01

    Frost resistance of fibre reinforced concrete with 2.5-4.2% air and 6-9% air (% by volume in fresh concrete) casted in the laboratory and in-situ is compared. Steel fibres with hooked ends (ZP, length 30 mm) and polypropylene fibres (PP, CS, length 12 mm) are applied. It is shown that· addition...... of 0.4-1% by volume of fibres cannot replace air entrainment in order to secure a frost resistant concrete; the minimum amount of air needed to make the concrete frost resistant is not changed when adding fibres· the amount of air entrainment must be increased when fibres are added to establish...

  12. Frost resistance of fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1999-01-01

    of 0.4-1% by volume of fibres cannot replace air entrainment in order to secure a frost resistant concrete; the minimum amount of air needed to make the concrete frost resistant is not changed when adding fibres· the amount of air entrainment must be increased when fibres are added to establish......Frost resistance of fibre reinforced concrete with 2.5-4.2% air and 6-9% air (% by volume in fresh concrete) casted in the laboratory and in-situ is compared. Steel fibres with hooked ends (ZP, length 30 mm) and polypropylene fibres (PP, CS, length 12 mm) are applied. It is shown that· addition...

  13. Halloysite reinforced epoxy composites with improved mechanical properties

    Directory of Open Access Journals (Sweden)

    Saif Muhammad Jawwad

    2016-03-01

    Full Text Available Halloysite nanotubes (HNTs reinforced epoxy composites with improved mechanical properties were prepared. The prepared HNTs reinforced epoxy composites demonstrated improved mechanical properties especially the fracture toughness and flexural strength. The flexural modulus of nanocomposite with 6% mHNTs loading was 11.8% higher than that of neat epoxy resin. In addition, the nanocomposites showed improved dimensional stability. The prepared halloysite reinforced epoxy composites were characterized by thermal gravimetric analysis (TGA. The improved properties are attributed to the unique characteristics of HNTs, uniform dispersion of reinforcement and interfacial coupling.

  14. Fatigue micromechanism characterisation in carbon fibre reinforced polymers using synchrotron radiation computed tomography

    OpenAIRE

    Garcea, S.C.; Mavrogordato, M.N.; Scott, A.E.; Sinclair, I.; Spearing, S.M.

    2014-01-01

    In situ synchrotron radiation computed tomography (SRCT) has been used to evaluate fatigue damage micromechanisms in [90/0]s carbon fibre reinforced epoxy double-edge notched specimens. Interactions between cracks and toughening particles have been identified within the epoxy, particularly: particles de-bonding ahead of the main crack tip, creating a preferential damage path, and the bridging of cracks by un-failed ligaments. The critical mechanism of fatigue crack growth appears to be the de...

  15. Characterisation of natural fibre reinforced PLA foams prepared by supercritical CO2 assisted extrusion

    Directory of Open Access Journals (Sweden)

    K. Bocz

    2016-09-01

    Full Text Available Natural fibre reinforced polylactic acid (PLA foams, as potential green replacements for petroleum-based polymer foams, were investigated. Highly porous (ε > 95% microcellular PLA foams were manufactured by supercritical CO2 assisted extrusion process. To overcome the inherently low melt strength of PLA, epoxy-functionalized chain extender was applied, while talc was added to improve its crystallization kinetics. The combined application of chain extender and talc effectively promoted the formation of uniform cell structures. The effect of cellulose and basalt fibre reinforcement on the foamability, morphology, structure and mechanical properties of the PLA foams were investigated as well. The addition of 5 wt% natural fibres promoted the cell nucleation, but caused non-uniform distribution of cell size due to the microholes induced by local fibre-matrix debonding. The compression strength of the manufactured basalt fibre reinforced PLA foams reached 40 kPa.

  16. Analysis of filler--fibre interaction in fly ash filled short fibre-epoxy ...

    Indian Academy of Sciences (India)

    These properties showed an improvement of about 30-40% as compared to the ones where a single reinforcement either ash or fibre was used. Further, they exhibited uniform distribution of defects whose population was least compared to the situation where only one component (either filler or fibre) as reinforcement was ...

  17. Evaluation of Defects in Multilayer Carbon Fibre Epoxy for Aeronautics Applications

    Directory of Open Access Journals (Sweden)

    M. Buonsanti

    2009-01-01

    Full Text Available Production of carbon fibre reinforced polymers is an elaborate process unfree from faults and problems. Problems during the manufacturing, such as plies' overlapping, can cause flaws in the resulting material, so compromising its integrity. Compared with metallic materials, carbon epoxy composites show a number of advantages. Within this framework, ultrasonic tests are effective to identify the presence of defects. In this paper a Finite Element Method approach is proposed for evaluating the most effective incidence angle of an ultrasonic probe with regard to defects' identification. According to our goal, the analysis has been carried out considering a single-line plane emitting source varying the probe angle of inclination. The proposed model looks promising to specially emphasize the presence of delaminations as well as massive breaking in a specimen of multilayer carbon fibre epoxy. Subsequently, simulation parameters and results have been exploited and compared, respectively, for a preliminary experimental in-lab campaign of measurements with encouraging results.

  18. Properties of self-compacting fibre reinforced concrete

    OpenAIRE

    Vandewalle, Lucie; Heirman, Gert

    2009-01-01

    The postcracking behaviour of fibre reinforced concrete is particularly influenced by the fibre distribution and the fibre orientation. One could suppose that in self-compacting fibre reinforced concrete (SCFRC) fibres orient along the flow due to the wall-effect, the flow direction and the velocity profile in the concrete. To investigate the fresh and hardened characteristics (mechanical properties, orientation and distribution of the fibres) of SCFRC and to relate them to those of tradition...

  19. The role of the epoxy resin: Curing agent ratio in composite interfacial strength by single fibre microbond test

    DEFF Research Database (Denmark)

    Minty, Ross; Thomason, James L.; Petersen, Helga Nørgaard

    2015-01-01

    This paper focuses on an investigation into the role of the epoxy resin: curing agent ratio in composite interfacial shear strength of glass fibre composites. The procedure involved changing the percentage of curing agent (Triethylenetetramine [TETA]) used in the mixture with several different...... percentages used, ranging from 4% up to 30%, including the stoichiometric ratio. It was found by using the microbond test, that there may exist a relationship between the epoxy resin to curing agent ratio and the level of adhesion between the reinforcing fibre and the polymer matrix of the composite....

  20. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    Wintec

    green composites involving Hibiscus sabdariffa fibre as a reinforcing material in urea–formaldehyde (UF) resin based polymer ... mixed Hibiscus sabdariffa fibre reinforced polymer composites such as tensile, compressive and wear proper- ties were ... in natural fibres and its applications in various fields. Natural fibres are ...

  1. Continuous jute fibre reinforced laminated paper composite and ...

    Indian Academy of Sciences (India)

    Plastic bags create a serious environmental problem. The proposed jute fibre reinforced laminated paper composite and reinforcement-fibre free paper laminate may help to combat the war against this pollutant to certain extent. The paper laminate, without reinforcement fibre, exhibited a few fold superiority in tensile ...

  2. Self-compacting fibre-reinforced concrete

    NARCIS (Netherlands)

    Grunewald, S.; Walraven, J.C.

    2001-01-01

    The project 'self-compacting fibre-reinforced concrete (SCFRC)' is part of the Dutch STW/PPM program - 'cement-bonded materials' - DCT.4010. Subproject III to which the project ,SCFRC' belongs deals with the development of new high performance concretes. The project 'SCFRC' aims at investigating the

  3. Effect of elevated temperature on the tensile strength of Napier/glass-epoxy hybrid reinforced composites

    Science.gov (United States)

    Ridzuan, M. J. M.; Majid, M. S. Abdul; Afendi, M.; Firdaus, A. Z. Ahmad; Azduwin, K.

    2017-11-01

    The effects of elevated temperature on the tensile strength of Napier/glass-epoxy hybrid reinforced composites and its morphology of fractured surfaces are discussed. Napier/glass-epoxy hybrid reinforced composites were fabricated by using vacuum infusion method by arranging Napier fibres in between sheets of woven glass fibres. Napier and glass fibres were laminated with estimated volume ratios were 24 and 6 vol. %, respectively. The epoxy resin was used as matrix estimated to 70 vol. %. Specimens were tested to failure under tension at a cross-head speed of 1 mm/min using Universal Testing Machine (Instron) with a load cell 100 kN at four different temperatures of RT, 40°C, 60°C and 80°C. The morphology of fractured surface of hybrid composites was investigated by field emission scanning electron microscopy. The result shows reduction in tensile strength at elevated temperatures. The increase in the temperature activates the process of diffusion, and generates critical stresses which cause the damage at first-ply or at the centre of the hybrid plate, as a result lower the tensile strength. The observation of FESEM images indicates that the fracture mode is of evolution of localized damage, from fibre/matrix debonding, matric cracking, delamination and fibre breakage.

  4. Multi scale analysis by acoustic emission of damage mechanisms in natural fibre woven fabrics/epoxy composites.

    Directory of Open Access Journals (Sweden)

    Touchard F.

    2010-06-01

    Full Text Available This paper proposes to develop an experimental program to characterize the type and the development of damage in composite with complex microstructure. A multi-scale analysis by acoustic emission has been developed and applied to hemp fibre woven fabrics/epoxy composite. The experimental program consists of tensile tests performed on single yarn, neat epoxy resin and composite materials to identify their AE amplitude signatures. A statistical analysis of AE amplitude signals has been realised and correlated with microscopic observations. Results have enabled to identify three types of damage in composites and their associated AE amplitudes: matrix cracking, interfacial debonding and reinforcement damage and fracture. Tracking of these damage mechanisms in hemp/epoxy composites has been performed to show the process of damage development in natural fibre reinforced composites.

  5. Machining of Fibre Reinforced Plastic Composite Materials.

    Science.gov (United States)

    Caggiano, Alessandra

    2018-03-18

    Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented.

  6. Machining of Fibre Reinforced Plastic Composite Materials

    Directory of Open Access Journals (Sweden)

    Alessandra Caggiano

    2018-03-01

    Full Text Available Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented.

  7. Machining of Fibre Reinforced Plastic Composite Materials

    Science.gov (United States)

    2018-01-01

    Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented. PMID:29562635

  8. Surface treated polypropylene (PP) fibres for reinforced concrete

    Energy Technology Data Exchange (ETDEWEB)

    López-Buendía, Angel M., E-mail: buendia@uv.es [AIDICO Technological Institute of Construction, Benjamin Franklin 17, 46380 Paterna, Valencia (Spain); Romero-Sánchez, María Dolores [AIDICO Technological Institute of Construction, Marble Technical Unit, Camí de Castella 4, 03660 Novelda. Alicante (Spain); Climent, Verónica [Lafarge Cementos, Polígono Sepes, Isaac Newton s/n, 46500 Sagunto, Valencia (Spain); Guillem, Celia [AIDICO Technological Institute of Construction, Marble Technical Unit, Camí de Castella 4, 03660 Novelda. Alicante (Spain)

    2013-12-15

    Surface treatments on a polypropylene (PP) fibre have contributed to the improvement of fibre/concrete adhesion in fibre-reinforced concrete. The treatments to the PP fibre were characterized by contact angle measurements, ATR-IR and XPS to analyse chemical alterations. The surface topography and fibre/concrete interaction were analysed by several microscopic techniques, namely optical petrographic, and scanning electron microscopy. Treatment modified the surface chemistry and topography of the fibre by introducing sodium moieties and created additional fibre surface roughness. Modifications in the fibre surface led to an increase in the adhesion properties between the treated fibres and concrete and an improvement in the mechanical properties of the fibre-reinforced concrete composite as compared to the concrete containing untreated PP fibres. Compatibility with the concrete and increased roughness and mineral surface was also improved by nucleated portlandite and ettringite mineral association anchored on the alkaline PP fibre surface, which is induced during treatment.

  9. Effect of resin system on the mechanical properties and water absorption of kenaf fibre reinforced laminates

    International Nuclear Information System (INIS)

    Rassmann, S.; Paskaramoorthy, R.; Reid, R.G.

    2011-01-01

    The objective of this study is to compare the mechanical and water absorption properties of kenaf (Hibiscus cannabinus L.) fibre reinforced laminates made of three different resin systems. The use of different resin systems is considered so that potentially complex and expensive fibre treatments are avoided. The resin systems used include a polyester, a vinyl ester and an epoxy. Laminates of 15%, 22.5% and 30% fibre volume fraction were manufactured by resin transfer moulding. The laminates were tested for strength and modulus under tensile and flexural loading. Additionally, tests were carried out on laminates to determine the impact energy, impact strength and water absorption. The results revealed that properties were affected in markedly different ways by the resin system and the fibre volume fraction. Polyester laminates showed good modulus and impact properties, epoxy laminates displayed good strength values and vinyl ester laminates exhibited good water absorption characteristics. Scanning electron microscope studies show that epoxy laminates fail by fibre fracture, polyester laminates by fibre pull-out and vinyl ester laminates by a combination of the two. A comparison between kenaf and glass laminates revealed that the specific tensile and flexural moduli of both laminates are comparable at the volume fraction of 15%. However, glass laminates have much better specific properties than the kenaf laminates at high fibre volume fractions for all three resins used.

  10. Tensile properties of structural fibre reinforced concrete

    Science.gov (United States)

    Tipka, M.; Vašková, J.

    2017-09-01

    The paper deals with the comparison of several loading tests, which are using for determination of tensile strength of cementitious composites. The paper describes several test methods, their advantages, disadvantages and possible outputs. In the experimental program several recipes of concrete and fibre reinforced concrete were tested in splitting test, 3-point and 4-point bending tests and in 2 variants of axial tension test. Tension strength ratios and conversion factors between loading tests were determined for each recipe, based on test results.

  11. Design of fibre reinforced PV concepts for building integrated applications

    NARCIS (Netherlands)

    Reinders, Angelina H.M.E.; de Wit, H.; de Boer, Andries; Ossenbrink Sinke, W.; Helm, P.

    2009-01-01

    Fibre reinforced polymers present an interesting encapsulation medium for PV-modules. Glass fibres can provide increased strength and stiffness to thin polymer layers overcoming the brittleness and limited deformability of glass-panes. Glass fibre reinforced polymers allows for transparency over a

  12. Fibre-reinforced hydrogels for tissue engineering

    Science.gov (United States)

    Waters, Sarah; Byrne, Helen; Chen, Mike; Dias Castilho, Miguel; Kimpton, Laura; Please, Colin; Whiteley, Jonathan

    2017-11-01

    Tissue engineers aim to grow replacement tissues in vitro to replace those in the body that have been damaged through age, trauma or disease. One approach is to seed cells within a scaffold consisting of an interconnected 3D-printed lattice of polymer fibres, cast in a hydrogel, and subject the construct (cell-seeded scaffold) to an applied load in a bioreactor. A key question is to understand how this applied load is distributed throughout the construct to the mechanosensitive cells. To address this, we exploit the disparate length scales (small inter-fibre spacing compared with construct dimensions). The fibres are treated as a linear elastic material and the hydrogel as a poroelastic material. We employ homogenisation theory to derive equations governing the material properties of a periodic, elastic-poroelastic composite. To validate the mobel, model solutions are compared to experimental data describing the unconfined compression of the fibre-reinforced hydrogels. The model is used to derive the bulk mechanical properties of a cylindrical construct of the composite material for a range of fibre spacings, and the local mechanical environment experienced by cells embedded within the construct is determined. Funded by the European Union Seventh Framework Programme (FP7/2007-2013).

  13. Comparison of two novel approaches to model fibre reinforced concrete

    NARCIS (Netherlands)

    Radtke, F.K.F.; Simone, A.; Sluys, L.J.

    2009-01-01

    We present two approaches to model fibre reinforced concrete. In both approaches, discrete fibre distributions and the behaviour of the fibre-matrix interface are explicitly considered. One approach employs the reaction forces from fibre to matrix while the other is based on the partition of unity

  14. Mechanical properties of thermoplastic composites reinforced with Entada Mannii fibre

    Directory of Open Access Journals (Sweden)

    Oluwayomi BALOGUN

    2017-06-01

    Full Text Available The mechanical properties and fracture mechanisms of thermoplastic composites reinforced with Entada mannii fibres was investigated. Polypropylene reinforced with 1, 3, 5, and 7 wt% KOH treated and untreated Entada mannii fibres were processed using a compression moulding machine. The tensile properties, impact strength, and flexural properties of the composites were evaluated while the tensile fracture surface morphology was examined using scanning electron microscopy. The results show that reinforcing polypropylene with Entada mannii fibres resulted in improvement of the tensile strength and elastic modulus. This improvement is remarkable for 5 wt% KOH treated Entada mannii fibre reinforced composites by 28 % increase as compared with the unreinforced polypropylene. The composites reinforced with Entada mannii fibres also had impact strength values of 70 % higher than the unreinforced polypropylene. However, the polypropylene reinforced with 5 and 7wt% KOH treated fibres exhibited significantly higher flexural strength and Young’s modulus by 53% and 52% increase as compared with the unreinforced polypropylene. The fracture surface of the polypropylene composites reinforced with untreated Entada mannii fibres were characterized by fibre debonding, fibre pull-out and matrix yielding while less voids and fibre pull-outs are observed in the composites reinforced with KOH treated Entada mannii fibres. v

  15. Investigation of digital light processing using fibre-reinforced polymers

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pedersen, David Bue; Nielsen, Jakob Skov

    2016-01-01

    -reinforced polymers in digital light processing (DLP) are limited. Fibre-reinforced polymer composites were manufactured into test objects using digital light processing. Short fibres were used in an unordered manner. An anisotropic property due to fibre orientation within the material was observed. The importance......Literature research shows multiple applications of fibre-reinforced polymers (FRP) respectively in fused deposition modelling and gypsum printing influencing the quality of the products in terms of stress and strain resistance as well as flexibility. So far, applications of fibre...... of fibre length and shape compared to layer thickness has been investigated including concepts to circumvent clustering of the fibres.This research contributes to the implementation of fibre-reinforced polymers in additive manufacturing technologies. Digital light processing allows generation...

  16. Thermal expansion of fibre-reinforced composites

    International Nuclear Information System (INIS)

    Schneider, B.

    1991-07-01

    The integral thermal expansion and the coefficient of thermal expansion (CTE) of carbon and Kevlar fibre-reinforced composites were measured with high accuracy from 5 K to room temperature. For this, a laser dilatometer and a sophisticated measuring procedure were used. CTE dependence on the orientation angle ω of angle-ply laminates was determined for samples with 5 different fibre alignments (UD 0deg, +/-30deg, +/-45deg, +/-60deg and UD 90deg). A high variability of the CTE with the orientation angle was shown. At angles of approximately +/-30deg even negative CTEs were found. With suitable reinforcing fibres being selected, their absolute values rose up to 30-100% of the positive CTEs of metals. Hence, composites of this type would be suitable as compensating materials in metal constructions where little thermal expansion is desired. To check the lamination theory, theoretical computations of the CTE- ω -dependence were compared with the measured values. An excellent agreement was found. Using the lamination theory, predictions about the expansion behaviour of angle-ply laminates can be made now, if the thermal and mechanical properties of the unidirectional (UD) laminate are known. Furthermore, it is possible to carry out simulation computations aimed at investigating the influence of a single parameter of the UD-laminate (e.g. shear modulus) on the expansion of the angle-ply laminate. (orig.) [de

  17. Fibre reinforced concrete in flexure and single fibre pull-out test: a correlation

    Science.gov (United States)

    Manca, M.; Ciancio, D.; Dight, P.

    2017-09-01

    The aim of the present work is to assess whether a single fibre pull-out test can be related to the behaviour of multiple fibres in fibre reinforced concrete under bending condition. A simple model based on the stress block theory is described and compared with experimental results on three point bending tests with aligned fibres.

  18. Effect of Glass Reinforced Epoxy (GRE) pipe filled with Geopolymer Materials for Piping Application: Compression Properties

    OpenAIRE

    Abu Hashim Mohammad Firdaus; Abdullah Mohd Mustafa Al Bakri; Ghazali Che Mohd Ruzaidi; Hussin Kamarudin; Binhussain Mohammed; Omar Mohd Firdaus

    2016-01-01

    The aim of this paper is to achieve the highest compressive strength of glass reinforced epoxy pipe with the geopolymer filler content of weight percentage that were used in glass reinforced epoxy pipe. The samples were prepared by using the filament winding method. The effect of weight percentage of geopolymer materials in epoxy hardener was studied under mechanical testing, which is using the compression test. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled wi...

  19. Influence of fibre orientation on the performance of steel fibre-reinforced concrete

    OpenAIRE

    Grünewald, Steffen; Laranjeira de Oliveira, Filipe; Walraven, Joost; Aguado de Cea, Antonio; Molins i Borrell, Climent

    2012-01-01

    The performance of fibre-reinforced materials in the hardened state depends on the material behaviour, the production method and influences related to the structure. The position and the orientation of fibres in a structure can differ from the homogenous distribution and the random orientation in a mixer. Due to the flow of the concrete, fibres are able to orient which makes the prediction of the structural behaviour of fibre-reinforced concrete more complex, but it also offers the potential ...

  20. optimisation of thickness of fibre reinforced polymer sheets

    African Journals Online (AJOL)

    user

    2017-01-01

    Jan 1, 2017 ... OPTIMISATION OF THICKNESS OF FIBRE REINFORCED POLYMER SHEETS FOR. STRENGTHENING REINFORCED CONCRETE BEAMS WITH FLEXURAL DEFICIENCY. J. M. Kaura. DEPARTMENT OF CIVIL ENGINEERING, AHMADU BELLO UNIVERSITY, ZARIA, KADUNA STATE. NIGERIA.

  1. Experimental Investigation and Taguchi Optimisation of Drilling Properties on Teak Wood Reinforced Epoxy Resin

    Science.gov (United States)

    Lilly Mercy, J.; Shaqir Tanvir, Mohamed; Swaroopkanth, K.

    2017-05-01

    The drilling properties of teak reinforced epoxy resin composite are explored in this work. The thrust force and temperature during the drilling process was found and optimised. Nine holes were drilled in accordance with L9 orthogonal array on Medium Density Fibre board and Teak wood reinforced epoxy composite board and the thrust force and temperature induced during drilling is measured. Drilling experiments were conducted using CNC Vertical drilling machine and the thrust force was measured using dynamometer and temperature using infra-red thermometer. The experiments were conducted with varying levels of spindle speed and feed rate and optimised using Taguchi optimisation. It was observed that higher thrust and temperature were observed while drilling teak wood composite due to the high mechanical strength of teak wood. The hard and brittle properties of the resin seemed to be more pronounced in the composite. The experimental results were optimised to find the best combination of input parameters for reduced thrust and temperature. When speed increases, thrust force decreases and temperature increases. When feed increases, thrust force increases and temperature decreases. Experimental findings encouragesto use teak wood reinforced epoxy resin as a substitute for the traditionally used Medium Density Fibre Board. The percentage of mixing of teak dust can be increased with various resin combinations to arrive at the best suitable combination for obtaining optimal mechanical properties.

  2. Self Healing Fibre-reinforced Polymer Composites: an Overview

    Science.gov (United States)

    Bond, Ian P.; Trask, Richard S.; Williams, Hugo R.; Williams, Gareth J.

    Lightweight, high-strength, high-stiffness fibre-reinforced polymer composite materials are leading contenders as component materials to improve the efficiency and sustainability of many forms of transport. For example, their widespread use is critical to the success of advanced engineering applications, such as the Boeing 787 and Airbus A380. Such materials typically comprise complex architectures of fine fibrous reinforcement e.g. carbon or glass, dispersed within a bulk polymer matrix, e.g. epoxy. This can provide exceptionally strong, stiff, and lightweight materials which are inherently anisotropic, as the fibres are usually arranged at a multitude of predetermined angles within discrete stacked 2D layers. The direction orthogonal to the 2D layers is usually without reinforcement to avoid compromising in-plane performance, which results in a vulnerability to damage in the polymer matrix caused by out-of-plane loading, i.e. impact. Their inability to plastically deform leaves only energy absorption via damage creation. This damage often manifests itself internally within the material as intra-ply matrix cracks and inter-ply delaminations, and can thus be difficult to detect visually. Since relatively minor damage can lead to a significant reduction in strength, stiffness and stability, there has been some reticence by designers for their use in safety critical applications, and the adoption of a `no growth' approach (i.e. damage propagation from a defect constitutes failure) is now the mindset of the composites industry. This has led to excessively heavy components, shackling of innovative design, and a need for frequent inspection during service (Richardson 1996; Abrate 1998).

  3. Epoxy-based carbon nanotubes reinforced composites

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2011-04-01

    Full Text Available Epoxy or polyepoxide is a thermosetting epoxide polymer that cures (polymerizes and cross-links) when mixed with a curing agent or "hardener". Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. A newly...

  4. Oxidation of lignin in hemp fibres by laccase: effects on mechanical properties of hemp fibres and unidirectional fibre/epoxy composites

    DEFF Research Database (Denmark)

    Liu, Ming; Baum, Andreas; Odermatt, Jürgen

    2017-01-01

    Laccase activity catalyzes oxidation and polymerization of phenols. The effect of laccase treatment on the mechanical properties of hemp fibres and hemp fibre/epoxy composites was examined. Laccase treatment on top of 0.5% EDTA + 0.2% endo-polygalacturonase (EPG) treatments increased the mechanical...... properties of hemp fibres and fibre/epoxy composites. Comparing all fibre treatments, composites with 0.5% EDTA + 0.2% EPG + 0.5% laccase treated fibres had highest stiffness of 42 GPa and highest ultimate tensile strength (UTS) of 326 MPa at a fibre volume content of 50%. The thermal resistance of hemp...... hemp fibres and their composites were due to laccase catalyzed polymerization of lignin moieties in hemp fibres....

  5. Mechanical property analysis of kenaf–glass fibre reinforced ...

    Indian Academy of Sciences (India)

    mechanical properties and are used as reinforcing materials in polymer composites [3–5]. However, the products made from natural fibre composite are still limited to the structural applications, owing to their poor mechanical prop- erties [6]. To solve this issue, the natural fibres are hybridized with synthetic fibres to make the ...

  6. Crack Formation During Hardening in Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Olesen, John Forbes; Stang, Henrik

    1996-01-01

    The objective of this project is to establish models for the development of cracks in the early age of fibre reinforced concrete due to restrained shrinkage and temperature variations. These models will be based on measurements of age dependant material properties including the post crack response...... of the fibre reinforced concrete....

  7. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  8. Microanalytical investigation of fibre-reinforced ceramic materials

    International Nuclear Information System (INIS)

    Meier, B.; Grathwohl, G.

    1989-01-01

    Microanalytical investigations have been made on samples of ceramic fibres (SiC fibres, (Nicalon) C fibre coated with TiN) and fibre-reinforced ceramics (SiC-and glass-matrices). High resolution Auger electron spectroscopy (HRAES), electron probe microanalysis (EPMA) and scanning electron microscopy were employed for these examinations. Analysis was best performed with HRAES on account of its lateral and depth resolution. Some of the problems involved in this technique are discussed e.g. electron beam effects. AES depth profiles of ceramic fibres are reported and compared with the surface analysis of fibres in the composites after being broken in situ. (orig.)

  9. Non-Destructive Testing of Steel Fibre Reinforced Concrete

    Science.gov (United States)

    Corbett, D.; Tronca, G.

    2017-09-01

    For standard reinforced concrete, there are several non-destructive test (NDT) methods available for measuring the concrete cover and for locating subsurface objects and defects. Whether or not these methods may also be applied to fibre reinforced concrete has been the subject of a recent study. The results and a recommendation for the most suitable technology for use with fibre reinforced concrete is the topic of this paper.

  10. Fibre-matrix interface properties in a wood fibre reinforced cement matrix

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Schlangen, H.E.J.G.

    2010-01-01

    Wood fibres can be a low cost reinforcement for cementitious materials for structural applications. In order to design a ductile cementitious material reinforced with softwood fibres the fibrematrix interface properties are studied. Pullout tests have been carried out to determine the bond strength

  11. Axial Compression Tests on Corroded Reinforced Concrete Columns Consolidated with Fibre Reinforced Polymers

    Directory of Open Access Journals (Sweden)

    Bin Ding

    2017-06-01

    Full Text Available Reinforced concrete structure featured by strong bearing capacity, high rigidity, good integrity, good fire resistance, and extensive applicability occupies a mainstream position in contemporary architecture. However, with the development of social economy, people need higher requirements on architectural structure; durability, especially, has been extensively researched. Because of the higher requirement on building material, ordinary reinforced concrete structure has not been able to satisfy the demand. As a result, some new materials and structures have emerged, for example, fibre reinforced polymers. Compared to steel reinforcement, fibre reinforced polymers have many advantages, such as high tensile strength, good durability, good shock absorption, low weight, and simple construction. The application of fibre reinforced polymers in architectural structure can effectively improve the durability of the concrete structure and lower the maintenance, reinforcement, and construction costs in severe environments. Based on the concepts of steel tube concrete, fibre reinforced composite material confined concrete, and fibre reinforced composite material tubed concrete, this study proposes a novel composite structure, i.e., fibre reinforced composite material and steel tube concrete composite structure. The structure was developed by pasting fibre around steel tube concrete and restraining core concrete using fibre reinforced composite material and steel tubes. The bearing capacity and ultimate deformation capacity of the structure was tested using column axial compression test.

  12. Additive manufacturing of short and mixed fibre-reinforced polymer

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, James; Duoss, Eric B.; Rodriguez, Jennifer Nicole; Worsley, Marcus A.; King, Michael J.

    2018-01-09

    Additive manufacturing of a fiber-reinforced polymer (FRP) product using an additive manufacturing print head; a reservoir in the additive manufacturing print head; short carbon fibers in the reservoir, wherein the short carbon fibers are randomly aligned in the reservoir; an acrylate, methacrylate, epoxy, cyanate ester or isocyanate resin in the reservoir, wherein the short carbon fibers are dispersed in the acrylate, methacrylate, epoxy, cyanate ester or isocyanate resin; a tapered nozzle in the additive manufacturing print head operatively connected to the reservoir, the tapered nozzle produces an extruded material that forms the fiber-reinforced polymer product; baffles in the tapered nozzle that receive the acrylate, methacrylate, epoxy, cyanate ester or isocyanate resin with the short carbon fibers dispersed in the acrylate, methacrylate, epoxy, cyanate ester or isocyanate resin; and a system for driving the acrylate, methacrylate, epoxy, cyanate ester or isocyanate resin with the short carbon fibers dispersed in the acrylate, methacrylate, epoxy, cyanate ester or isocyanate resin from the reservoir through the tapered nozzle wherein the randomly aligned short carbon fibers in the acrylate, methacrylate, epoxy, cyanate ester or isocyanate resin are aligned by the baffles and wherein the extruded material has the short carbon fibers aligned in the acrylate, methacrylate, epoxy, cyanate ester or isocyanate resin that forms the fiber-reinforced polymer product.

  13. Thermal Conductivity of Structural Glass/Fibre Epoxy Composite as a Function of Fibre Orientation

    CERN Document Server

    Cugnet, D; Kuijper, A; Parma, Vittorio; Vandoni, Giovanna

    2002-01-01

    The LHC, the new superconducting particle accelerator presently under construction at CERN, makes use of some 1200 dipole magnets for orbit bending and 500 quadrupole magnets for focusing/defocusing of the circulating high-energy proton beams. Two or three column-type support posts sustain each cryomagnet. The choice of a convenient material for these supports is critical, because of the required high positioning accuracy of the magnets in their cryostats and stringent thermal budget requirements imposed by the LHC cryogenic system. A glass-fibre/epoxy resin composite has been chosen for its good combination of high stiffness and low thermal conductivity over the 2-293 K temperature range. Plies of long glass-fibres are stacked optimally yielding the best mechanical behaviour. However, heat leaks from the supports are influenced by the thermal characteristics of the composite, which in turn depend on the orientation of the fibres. To study the dependence of the thermal conductivity on fibre's orientation, we ...

  14. Ductile behavior of polyethylene fibre reinforced geopolymer composite

    Directory of Open Access Journals (Sweden)

    Ahmed Shaikh Faiz Uddin

    2017-01-01

    Full Text Available This paper presents the effects of various volume fractions of polyethylene (PE fibres of 0.5%, 1%, 1.5% and 2% on tensile, flexure and compressive behavior of PE fibres reinforced geopolymer composites (PE-FRGC. Results show that the 1% PE fibre by volume is the optimum fibre volume fraction for fly ash geopolymer composite, which exhibit superior strain and deflection hardening behavior in uni-axial tension and three-point bending, respectively. Results also show that the compressive strength of the composites decreases with increase in volume fractions of PE fibre. The fibre surface examination of PE fibre in the gopolymer matrix using scanning electron microscope (SEM and energy dispersive spectroscopy (EDS revealed no significant damage of PE fibre in the alkaline geopolymer matrix.

  15. Effect of Sodium bicarbonate on Fire behaviour of tilled E- Glass Reinforced Epoxy Composites

    Science.gov (United States)

    Girish, S.; Devendra, K.; Bharath, K. N.

    2016-09-01

    Composites such as fibre reinforced polymers give us the good mechanical properties, but their fire behaviour is not appreciable and needs to be improved. In this work, E- glass fiber is used as a reinforcement material and Epoxy resin is used as a matrix with particulate sodium bi-carbonate (NaHCO3) is used as additive. The hand lay-up technique is adopted for the development of composites by varying percentage of additive. All the tests were conducted according to ASTM standards to study the Fire behaviour of the developed composites. The different fire properties like Ignition time, mass loss rate and flame propagation rate of Fiber Reinforced Polymers (FRP) with NaHCO3 are compared with neat FRPs. It is found that the ignition time increases as the percentage of additive is increased.

  16. Experimental Characterization of Carbon Fibre T700 / Epoxy towpreg for Space Applications

    OpenAIRE

    S.Sankar Reddy; Dr.C.Yuvraj

    2015-01-01

    This document covers detailed experimental characterization of Carbon Fibre T 700/Epoxy towpreg.The experimental characterization of carbon fibre T 700/Epoxy towpreg composite material is necessary required for generation of mechanical properties data for analysis, design, and fabrication of structural components using that material and for quality control of the material. The testing of composite materials offers unique surprises because of the special characteristics of composit...

  17. Rheology of Carbon Fibre Reinforced Cement-Based Mortar

    International Nuclear Information System (INIS)

    Banfill, Phillip F. G.; Starrs, Gerry; McCarter, W. John

    2008-01-01

    Carbon fibre reinforced cement based materials (CFRCs) offer the possibility of fabricating 'smart' electrically conductive materials. Rheology of the fresh mix is crucial to satisfactory moulding and fresh CFRC conforms to the Bingham model with slight structural breakdown. Both yield stress and plastic viscosity increase with increasing fibre length and volume concentration. Using a modified Viskomat NT, the concentration dependence of CFRC rheology up to 1.5% fibre volume is reported

  18. Continuous jute fibre reinforced laminated paper composite and ...

    Indian Academy of Sciences (India)

    Administrator

    laminates and composites was done by tensile test. 2. Experimental. 2.1 Materials. In the present investigation, two different types of kraft papers and an ONP (old news paper) were fibre- reinforced using jute fibre of average diameter, 0⋅045 mm and tensile strength, 470 MPa. Thickness, tensile strength and weight of ...

  19. Effect of moisture on natural fibre reinforced plastics | Ogakwu | West ...

    African Journals Online (AJOL)

    In this research, the rate of moisture absorption of the composites reinforced with natural fibres – Ukam plant fibres (chochlostermum placoni) were studied and determined.Composite cubes and plates of different sizes were prepared, then immersed in water for 24 hours at room temperature in order to determine the extent ...

  20. Service life prediction and fibre reinforced cementitious composites

    DEFF Research Database (Denmark)

    Stoklund Larsen, E.

    The present Ph.D.thesis addresses the service life concept on the fibre reinforced cementitious composites. The advantages and problems of adding fibre to a cementitious matrix and the influence on service life are described. In SBI Report 221, Service life prediction and cementitious somposites,...

  1. GLASS-FIBRE REINFORCED COMPOSITES: THE EFFECT OF ...

    African Journals Online (AJOL)

    The primary objective of this research work is to analyse the effect of fibre loading and orientation on the tensile and impact strength of the polymeric composite materials. Fibre reinforced composite materials have been reported to have attracted many applications in view of its low weight and superior strength when ...

  2. Stereology of concrete reinforced with short steel fibres

    NARCIS (Netherlands)

    Stroeven, P.

    1986-01-01

    Mechanical tests on steel fibre reinforced concrete (SFRC) can only be interpreted on the basis of a structural analysis. Stereological tools are available for that purpose. Results of recent investigations will be presented, revealing quite complex characteristics of the fibre dispersion in the

  3. Characterization of Epoxy Composites Reinforced with Wax Encapsulated Microcrystalline Cellulose

    Directory of Open Access Journals (Sweden)

    Yuanfeng Pan

    2016-11-01

    Full Text Available The effect of paraffin wax encapsulated microcrystalline cellulose (EMC particles on the mechanical and physical properties of EMC/epoxy composites were investigated. It was demonstrated that the compatibility between cellulose and epoxy resin could be maintained due to partial encapsulation resulting in an improvement in epoxy composite mechanical properties. This work was unique because it was possible to improve the physical and mechanical properties of the EMC/epoxy composites while encapsulating the microcrystalline cellulose (MCC for a more homogeneous dispersion. The addition of EMC could increase the stiffness of epoxy composites, especially when the composites were wet. The 1% EMC loading with a 1:2 ratio of wax:MCC demonstrated the best reinforcement for both dry and wet properties. The decomposition temperature of epoxy was preserved up to a 5% EMC loading and for different wax:MCC ratios. An increase in wax encapsulated cellulose loading did increase water absorption but overall this absorption was still low (<1% for all composites.

  4. Adhesion strength improvement of epoxy resin reinforced with nanoelastomeric copolymer

    International Nuclear Information System (INIS)

    Khoee, Sepideh; Hassani, Narges

    2010-01-01

    Research highlights: → Elastomeric nanoparticle (ENP) was prepared via miniemulsion polymerization. → ENP was added to epoxy resin (ER) with different amounts. → The lap shear strength (LSS) of different ENP/ER was measured. → The fractured surfaces were examined by scanning electron microscopy (SEM). - Abstract: Nano-sized copoly(styrene-butylacrylate-ethylenglycoldimethacrylate) (St-BA-EGDMA) particles were added at different contents to improve the toughness of diglycidyl ether of bisphenol A epoxy resin (ER) using piperidine as a curing agent. Transmission electron microscopy (TEM) proved that nanoelastomer was finely dispersed in the epoxy adhesive. To compare the adhesion strength of different adherents utilizing both modified and unmodified epoxy adhesive, the lap shear strength (LSS) test was measured as a function of elastomeric nanoparticles (ENP) amount. Scanning electron microscopy (SEM) and FTIR were used to investigate the interface morphology and chemical composition of adherent and epoxy adhesive. The result indicated that the adhesion strength was increased dramatically by addition of nanoparticles compared with that of pure epoxy adhesive. The highest adhesion strength was obtained with 20 wt% elastomeric nanoparticles. It was found that reinforcement with nanoparticles improved the fracture toughness.

  5. The effect of ion implantation on the tribomechanical properties of carbon fibre reinforced polymers

    International Nuclear Information System (INIS)

    Mistica, R.; Sood, D.K.; Janardhana, M.N.

    1993-01-01

    Graphite fibre reinforced epoxy composite material (GFRP) is used extensively in the aerospace and other industries for structural application. The trend is to address the 20 to 30 year life endurance of this material in service. Mechanical joints in air crafts are exposed to dynamic loads during service and wear may be experienced by the composite material joint. Generally it has been shown that graphite fibre reinforced polymers have superior wear and friction properties as compared with the unfilled polymers. In the described experiment, ion implantation was used as a novel surface treatment. Wear and friction of a polymer composite material (GFRP) was studied and ion implantation was used in order to observe the effect on the tribomechanical properties of the material. It was found that ion implantation of C on GFRP sliding against Ti changes the tribological properties of the system, and in particular decreases the coefficient of friction and wear. 4 refs., 2 figs

  6. The effect of ion implantation on the tribomechanical properties of carbon fibre reinforced polymers

    Energy Technology Data Exchange (ETDEWEB)

    Mistica, R.; Sood, D.K. [Royal Melbourne Inst. of Tech., VIC (Australia); Janardhana, M.N. [Deakin University, Geelong, VIC (Australia). School of Engineering and Technology

    1993-12-31

    Graphite fibre reinforced epoxy composite material (GFRP) is used extensively in the aerospace and other industries for structural application. The trend is to address the 20 to 30 year life endurance of this material in service. Mechanical joints in air crafts are exposed to dynamic loads during service and wear may be experienced by the composite material joint. Generally it has been shown that graphite fibre reinforced polymers have superior wear and friction properties as compared with the unfilled polymers. In the described experiment, ion implantation was used as a novel surface treatment. Wear and friction of a polymer composite material (GFRP) was studied and ion implantation was used in order to observe the effect on the tribomechanical properties of the material. It was found that ion implantation of C on GFRP sliding against Ti changes the tribological properties of the system, and in particular decreases the coefficient of friction and wear. 4 refs., 2 figs.

  7. Compressive behaviour at High Temperatures of Fibre Reinforced Concretes

    Directory of Open Access Journals (Sweden)

    S. O. Santos

    2009-01-01

    Full Text Available This paper summarizes the research that is being carried out at the Universities of Coimbra and Rio de Janeiro, on fibre reinforced concretes at high temperatures. Several high strength concrete compositions reinforced with fibres (polypropylene, steel and glass fibres were developed. The results of compressive tests at high temperatures (300 °C, 500 °C and 600 °C and after heating and cooling down of the concrete are presented in the paper. In both research studies, the results indicated that polypropylene fibers prevent concrete spalling. 

  8. A validation of the fibre orientation and fibre length attrition prediction for long fibre-reinforced thermoplastics

    International Nuclear Information System (INIS)

    Hopmann, Ch.; Weber, M.; Haag, J. van; Schöngart, M.

    2015-01-01

    To improve the mechanical performance of polymeric parts, fibre reinforcement has established in industrial applications during the last decades. Next to the widely used Short Fibre-reinforced Thermoplastics (SFT) the use of Long Fibre-reinforced Thermoplastics (LFT) is increasingly growing. Especially for non-polar polymeric matrices like polypropylene (PP), longer fibres can significantly improve the mechanical performance. As with every kind of discontinuous fibre reinforcement the fibre orientations (FO) show a high impact on the mechanical properties. On the contrary to SFT where the local fibre length distribution (FLD) can be often neglected, for LFT the FLD show a high impact on the material’s properties and has to be taken into account in equal measure to the FOD. Recently numerical models are available in commercial filling simulation software and allow predicting both the local FOD and FLD in LFT parts. The aim of this paper is to compare i.) the FOD results and ii) the FLD results from available orientation- and fibre length attrition-models to those obtained from experimental data. The investigations are conducted by the use of different injection moulded specimens made from long glass fibre reinforced PP. In order to determine the FOD, selected part sections are examined by means of Computed Tomographic (CT) analyses. The fully three dimensional measurement of the FOD is then performed by digital image processing using grey scale correlation. The FLD results are also obtained by using digital image processing after a thermal pyrolytic separation of the polymeric matrix from the fibres. Further the FOD and the FLD are predicted by using a reduced strain closure (RSC) as well as an anisotropic rotary diffusion - reduced strain closure model (ARD-RSC) and Phelps-Tucker fibre length attrition model implemented in the commercial filling software Moldflow, Autodesk Inc., San Rafael, CA, USA

  9. Stainless steel reinforcement as a replacement for epoxy coated steel in bridge decks : final report.

    Science.gov (United States)

    2013-08-01

    The corrosion resistance of 2304 stainless steel reinforcement and stainless steel clad reinforcement was compared to conventional and epoxy-coated reinforcement (ECR). 2304 stainless steel was tested in both the as-received condition (dark mottled f...

  10. Creep behaviour of macro glass fibre reinforced concrete beams

    Science.gov (United States)

    Löber, P.; Heiden, B.; Holschemacher, K.

    2017-09-01

    This paper aims to present a creep study on structural concrete reinforced with macro glass fibres and wants to contribute to the understanding of creep behaviour of fibre reinforced concrete (FRC). Fibre reinforced concrete beams have been subjected to bending and tested in cracked state under defined stress levels. Therefore, a four-point-bending test setup was chosen and the creep period was 372d. The aim was to determine creep coefficients and to test residual strength values afterwards. Results show a dependence of residual strength and applied stress level. It turned out, that the beams failed due to tertiary creep at stress levels between 65 and 70% of residual crack load at 0.5 mm pre-crack deflection. Nevertheless, all remaining specimens showed increased loads after creep period. Finally, the evaluation is conducted in comparison to other fibre types.

  11. safety of carbon fibre reinforced plastic hollow sections in compression

    African Journals Online (AJOL)

    ADMINUSER

    2014-01-06

    Jan 6, 2014 ... new material in civil engineering applications [1]. This paper investigates the compressive performances of CFRP hollow sections and modes of failure of reinforced concrete structural elements after strengthening with externally bonded carbon fibre- reinforced plastic (CFRP) tubes, and the effectiveness.

  12. Self-compacting fibre reinforced concrete applied in thin plates

    NARCIS (Netherlands)

    Grunewald, S.; Shionaga, R.; Walraven, J.C.

    2013-01-01

    Floor panels produced with traditionally vibrated concrete are relatively thick due to the need to reinforce concrete and consequently, heavy. Without the need to place rebars in panels and by applying self-compacting fibre reinforced concrete (SCFRC) the production process becomes more efficient.

  13. Mechanical behaviour of fibre reinforced concrete using soft - drink can

    Science.gov (United States)

    Ilya, J.; Cheow Chea, C.

    2017-11-01

    This research was carried out to study the behaviour of concrete, specifically compressive and flexural strength, by incorporating recycled soft drink aluminium can as fibre reinforcement in the concrete. Another aim of the research is to determine the maximum proportion of fibres to be added in the concrete. By following standard mix design, Ordinary Portland Cement (OPC) concrete was made to have a target mean strength of 30 N/mm2 with not more than 30 mm of slump. Having the same workability, OPC concrete with 0%, 1% and 2% of soft drink can aluminium fibre was prepared based on weight of cement. The specimens were tested for compressive strength and flexural strength. Laboratory test results based on short term investigation reveals that the compressive strength and flexural strength of concrete containing fibre are higher than of normal OPC concrete. Among two volume fractions, concrete with 1% of soft drink can fibre have performed better result in compressive strength and flexural strength compared with 2% amount of soft drink can fibre. The optimum proportion of aluminium fibre to be added in the concrete as fibre reinforcement is 1% fibre content by weight of cement which gave all the positive response from all the tests conducted.

  14. Flow modelling of steel fibre reinforced self-compacting concrete

    DEFF Research Database (Denmark)

    Svec, Oldrich

    in concrete can efficiently substitute or supplement conventional steel reinforcement, such as reinforcement bars. Ordinary concrete composition further makes the material stiff and non-flowable. Self-compacting concrete is an alternative material of low yield stress and plastic viscosity that does flow...... the fibre orientation and distribution in structural elements made of fibre reinforced self-compacting concrete. The existence of a such numerical tool is essential for the wider usage of the material. The developed numerical framework is capable of simulating free-surface flow of a suspension of explicitly...

  15. Characterization of the dynamic behaviour of flax fibre reinforced composites using vibration measurements

    Science.gov (United States)

    El-Hafidi, Ali; Birame Gning, Papa; Piezel, Benoit; Fontaine, Stéphane

    2017-10-01

    Experimental and numerical methods to identify the linear viscoelastic properties of flax fibre reinforced epoxy (FFRE) composite are presented in this study. The method relies on the evolution of storage modulus and loss factor as observed through the frequency response. Free-free symmetrically guided beams were excited on the dynamic range of 10 Hz to 4 kHz with a swept sine excitation focused around their first modes. A fractional derivative Zener model has been identified to predict the complex moduli. A modified ply constitutive law has been then implemented in a classical laminates theory calculation (CLT) routine.

  16. Shear Capacity of Steel and Polymer Fibre Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Kragh-Poulsen, Jens C.; Hoang, Cao Linh; Goltermann, Per

    2011-01-01

    This paper deals with the application of a plasticity model for shear strength estimation of fibre reinforced concrete beams without stirrups. When using plastic theory to shear problems in structural concrete, the so-called effective strengths are introduced, usually determined by calibrating...... of the tensile stress-crack opening relationship found from wedge splitting tests. To determine the effective compressive strength of FRC, it is proposed to adopt the formula used for conventional concrete and modify it by introducing a fibre enhancement factor to describe the effect of fibres on the compressive...... softening behaviour of FRC. The enhancement factor is determined as the ratio of the areas below the stress–strain curves for FRC and for conventional concrete. The outlined approach has been verified by shear testing of beams containing no fibres, 0.5% steel fibre volume and 0.5% polymer fibre volume...

  17. Fire Retardancy of Natural Fibre Reinforced Sheet Moulding Compound

    Science.gov (United States)

    Hapuarachchi, T. D.; Ren, G.; Fan, M.; Hogg, P. J.; Peijs, T.

    2007-07-01

    Due to environmental awareness and economical considerations, natural fibre reinforced polymer composites seem to present a viable alternative to synthetic fibre reinforced polymer composites such as glass fibres. This is a feasibility study to asses the potential application of natural fibre reinforced sheet moulding compound materials (NF-SMC) for the use in building applications, with particular emphases to their reaction to fire. The reinforcing fibres in this study were industrial hemp fibres. The cone calorimeter which asses the fire hazard of materials by Heat Release Rate (HRR) was used, radiant heat fluxes of 25 and 50 kW/m2 were utilised to simulate an ignition source and fully developed room fire conditions respectively. The results acquired here demonstrate that the NF-SMC can compete with current building materials in terms of their fire behaviour. The peak heat release value for the fire retardant (FR) NF-SMC was 176 kW/m2 conversely for a non-FR NF-SMC was 361 kW/m2.

  18. ELASTICITY of SHORT FIBRE REINFORCED POLYAMIDE: MORPHOLOGICAL AND NUMERICAl ANALYSIS OF FIBRE ORIENTATION EFFECTS

    Directory of Open Access Journals (Sweden)

    Francesca Cosmi

    2010-10-01

    Full Text Available The fatigue behaviour of injection moulded short fibre reinforced polymers depends upon fibre orientation, as shown in experiments conducted with notched specimens injected through different injection gates. The different fatigue behaviour is mainly related to the different local elastic properties, as determined by the different fibre orientation patterns, resulting into different strain distributions. In order to quantify the relationship between fibre orientation and elastic constants, the Cell Method was applied to volumes extracted from the specimens, reconstructed by micro-tomography.

  19. EVALUATION OF FIBRE LENGTH DISTRIBUTION IN A SHORT GLASS FIBRE REINFORCED PA-6

    Directory of Open Access Journals (Sweden)

    Camilla Ravalico

    2015-09-01

    Full Text Available The aim of this work is to evaluate the fibre length distribution in a polyamide reinforced by short glass fibre. The fibre length and the fibre orientation distributions strongly influence the mechanical properties of short fibre reinforced composites. The sample investigated is a 30GFPA6 (polyamide-6 reinforced by 30 % by weight glass fibre, extracted from an injection-moulded plate. The digital reconstruction of the three-dimensional structure of the sample was obtained by synchrotron radiation micro-computed tomography (micro-CT, a high spatial resolution non-destructive technique. One global and one local method have been tested for the automatic evaluation of the fibre length distribution in our sample. The global method is based on the mean fibre length distribution computed from the Star Length Distribution (SLD, a morphological parameter. The local method is based on a 3D skeletonize function. The results are discussed in the light of the experimental data available in literature.

  20. Micromechanics of the Interface in Fibre-Reinforced Cement Materials

    DEFF Research Database (Denmark)

    Stang, Henrik; Shah, S.P.

    1996-01-01

    In fibre reinforced brittle matrix composites the mechanicalbehaviour of the interface between the fibres and the matrix has avery significant influence on the overall mechanical behaviour ofthe composite material. Since brittle matrix composites are designed primarilywith the aim of improving...... the strength and ductility of the brittlematrix material rather than changing the overall stiffness,the ability of the fibres to interact with cracking processes in thematrix material is essential. Furthermore, since matrix cracking in afibre reinforced material can only take place with simultaneousinterfacial...... debonding of the fibre-matrix interface, it is clear thatspecial emphasis should be put on the mechanical and strengthproperties of the interface. The present paper gives an overview of the different modelsapplied in the literature in the description of interfaces incementitious composite materials...

  1. Reinforcing effect of nanosilica on polypropylene-nylon fibre composite

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Sinto [Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi-22, Kerala (India); Suma, K.K. [Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi-22, Kerala (India); Department of Chemistry, Maharaja' s college, Ernakulam, Kerala (India); Mendez, Jude Martin [Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi-22, Kerala (India); Department of Chemistry, St. Alberts college, Ernakulam, Kerala (India); George, K.E., E-mail: kegeorge@cusat.ac.i [Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi-22, Kerala (India)

    2010-04-15

    Polymer composites reinforced by both the micro and nano fillers is the subject of this paper. Polypropylene (PP)-nylon micro-fibre composites modified with nanosilica and modified nanosilica (using silane coupling agent) were prepared by melt compounding. The nanosilica prepared in the laboratory was used as reinforcing filler in PP-nylon fibre composites. The compounding characteristics and mechanical properties of the composites were studied. The equilibrium torque during compounding increased with the addition of nanosilica and modified nanosilica. The use of two types of fillers leads to synergistic effect on the mechanical properties of the composite. Composites with 1 wt.% nanosilica and 30 wt.% nylon fibre show high tensile strength, tensile modulus, flexural strength and flexural modulus. Composites modified with 1 wt.% nanosilica and 10 wt.% nylon fibre-PP composite show higher impact strength.

  2. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Nielsen, Laila

    1997-01-01

    (capillary water uptake) is used, involving an in-situ method and a laboratory method. Three different concrete qualities as well as steel fibres (ZP) and polypropylene fibres (PP) are used. Results of the durability tests on cracked FRC-beams are compared to results for uncracked FRC-beams and beams without......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by exposing beams to il-point bending until a predefined crack width is reached, using a newly developed test setup. As environmental load, exposure to water...... fibres and the influence of fibres and cracks on the water uptake is discussed....

  3. Effect of Glass Reinforced Epoxy (GRE pipe filled with Geopolymer Materials for Piping Application: Compression Properties

    Directory of Open Access Journals (Sweden)

    Abu Hashim Mohammad Firdaus

    2016-01-01

    Full Text Available The aim of this paper is to achieve the highest compressive strength of glass reinforced epoxy pipe with the geopolymer filler content of weight percentage that were used in glass reinforced epoxy pipe. The samples were prepared by using the filament winding method. The effect of weight percentage of geopolymer materials in epoxy hardener was studied under mechanical testing, which is using the compression test. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled with 10 – 40 weight percentage geopolymer filler which is white clay were prepared. The compression strength of the glass reinforced epoxy pipe filled geopolymer materials is determined using Instron Universal Testing under compression mode. It was found that compressive strength for samples with white clay geopolymer filler are much higher compare to glass reinforced epoxy pipe without geopolymer filler. Moreover, the compressive strength of glass reinforced epoxy pipe filled with white clay geopolymer filler was increased from 10 wt% to 30 wt% of geopolymer content. However, the compressive strength of glass reinforced epoxy pipe with white clay geopolymer filler suddenly decreased when added to 40 wt%. The results indicated that the blending of geopolymer materials in epoxy system can be obtained in this study.

  4. Woven Structures from Natural Fibres for Reinforcing Composites

    OpenAIRE

    Bernava, Aina; Manins, Maris; Strazds, Guntis

    2015-01-01

    The increase of production of woven structures from natural fibres for reinforced composites can be noticed in different sectors of economy. This can be explained by limited sources of raw materials and different environmental issues, as well as European Union guidelines for car manufacture [4]. This research produced 2D textile structures of hemp yarn and polypropylene yarn and tested the impact of added glass fibre yarn on the mechanical properties of the woven structur...

  5. Mechanical properties of pineapple leaf fibre reinforced polypropylene composites

    International Nuclear Information System (INIS)

    Arib, R.M.N.; Sapuan, S.M.; Ahmad, M.M.H.M.; Paridah, M.T.; Zaman, H.M.D. Khairul

    2006-01-01

    Pineapple leaf fibre, which is rich in cellulose, relative inexpensive and abundantly available has the potential for polymer-reinforced composite. The present study investigates the tensile and flexural behaviours of pineapple leaf fibre-polypropylene composites as a function of volume fraction. The tensile modulus and tensile strength of the composites were found to be increasing with fibre content in accordance with the rule of mixtures. The tensile modulus and tensile strength with a volume fraction 10.8% are 687.02 and 37.28 MPa, respectively. The flexural modulus gives higher value at 2.7% volume fraction. The flexural strength of the composites containing 5.4% volume fraction was found to be higher than that of pure polypropylene resin by 5.1%. Scanning electron microscopic studies were carried out to understand the fibre-matrix adhesion and fibre breakage

  6. Dimensional stability of pineapple leaf fibre reinforced phenolic composites

    Science.gov (United States)

    Asim, M.; Jawaid, M.; Abdan, K.; Ishak, M. R.

    2017-12-01

    In this research, pineapple leaves fibre (PALF)/phenolic resin (PF) composites were fabricated by hand lay-up method. The aim of this work is to investigate the physical properties (water absorption and thickness swelling) of PALF reinforced phenolic resin composites. Long-term water absorption (WA) and thickness swelling (TS) behaviours of the PALF/PF composites were investigated at several water immersion times. The effects of different fibre loading on WA and TS of PALF/PF composites were also analyzed. Obtained results indicated that the WA and TS of PALF/PF composites vary with fibres content and water immersion time before reaching to equilibrium. WA and TS of PALF/PF composites were increased by increasing fibre loading. Results obtained in this study will be used for further study on hybridization of PALF and Kenaf fibre based phenolic composites.

  7. Mechanical properties of pineapple leaf fibre reinforced polypropylene composites

    Energy Technology Data Exchange (ETDEWEB)

    Arib, R.M.N. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sapuan, S.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)]. E-mail: sapuan@eng.upm.edu.my; Ahmad, M.M.H.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Paridah, M.T. [Faculty of Forestry, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Zaman, H.M.D. Khairul [Radiation Processing Technology Division, Malaysian Institute for Nuclear Technology Research (MINT), Bangi 43000 Kajang, Selangor (Malaysia)

    2006-07-01

    Pineapple leaf fibre, which is rich in cellulose, relative inexpensive and abundantly available has the potential for polymer-reinforced composite. The present study investigates the tensile and flexural behaviours of pineapple leaf fibre-polypropylene composites as a function of volume fraction. The tensile modulus and tensile strength of the composites were found to be increasing with fibre content in accordance with the rule of mixtures. The tensile modulus and tensile strength with a volume fraction 10.8% are 687.02 and 37.28 MPa, respectively. The flexural modulus gives higher value at 2.7% volume fraction. The flexural strength of the composites containing 5.4% volume fraction was found to be higher than that of pure polypropylene resin by 5.1%. Scanning electron microscopic studies were carried out to understand the fibre-matrix adhesion and fibre breakage.

  8. (nanoclay and CaSiO3)-reinforced E-glass-reinforced epoxy ...

    Indian Academy of Sciences (India)

    Manufacturer. E-glass fibre. 195 μm. 2.48. 7-mil plain weaves unidirectional fabric Suntech Fibers Pvt Ltd, Chennai, India. CaSiO3. 75–150 μm. 2.9. Powder. Prince Chemicals, Bangalore, India. Organomodified clay 15–20 nm. 0.2–0.5. Powder. Sigma-Aldrich, Bangalore, India. Lapox L-12. (unmodified epoxy resin). —. 1.29.

  9. Durability of cracked fibre reinforced concrete structures exposed to chlorides

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Ekman, Tom; Hansen, Kurt Kielsgaard

    1999-01-01

    Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by exposing beams to 4-point bending until a predefined crack width is reached, using a newly developed test setup. Exposure to a concentrated chloride solution...... is used as environmental load. The chloride penetration is characterized both qualitatively (UV-test) and quantitatively (chloride profile) and by microscopy. The test programme involves three different concrete qualities. Both steel fibres and polypropylene fibres are used in the concrete beams as well...... as main reinforcement. The effect of the cracks, the fibres and the concrete quality on the chloride penetration is studied....

  10. Investigation of crack paths in natural fibre-reinforced composites

    Directory of Open Access Journals (Sweden)

    S. Keck

    2015-10-01

    Full Text Available Nowadays, fibre-reinforced composite materials are widely used in many fields, e.g. automotive and aerospace. Natural fibres such as flax and hemp provide good density specific mechanical properties. Additionally, the embodied production energy in natural fibres is much smaller than in synthetic ones. Within this paper the fracture mechanical behaviour of flax fibre-reinforced composites is discussed. Especially, this paper focuses on the determination and investigation of crack paths in compact tension specimens with three different fibre directions under a static as well as fatigue load. Differences and similarities in the obtained crack paths under different loading conditions are presented. Due to the pronounced orthotropic behaviour of those materials the crack path is not only governed by the stress state, but practically determined by the fibre direction and fibre volume fraction. Therefore, the well-known stress intensity factor solutions for the standard specimens are not applicable. It is necessary to carry out extensive numerical simulations to evaluate the stress intensity factor evolution along the growing crack in order to be able to determine fatigue crack growth rate curves. Those numerical crack growth simulations are performed with the three-dimensional crack simulation program ADAPCRACK3D to gain energy release rates and in addition stress intensity factors

  11. Structural Applications of Fibre Reinforced Concrete in the Czech Republic

    Science.gov (United States)

    Kohoutková, A.; Broukalová, I.

    2017-09-01

    The paper presents improvement of function and performance of the precast structural members by using fibre reinforced concrete (FRC) instead of ordinary reinforced concrete and attempts to transfer innovative technologies from laboratory in academic sphere into real industrial production which is cost-effective and brings about savings of labour and material. Three examples of successful technology transfer are shown - application of FRC in an element without common rebar reinforcement, in the element with steel rebar reinforcement and SFRC pre-tensioned structural element. Benefits of FRC utilization are discussed.

  12. Effects of Extrusion on Fibre Length in Sisal Fibre-Reinforced Polypropylene Composites

    Science.gov (United States)

    Pathi, Sridhar; Jayaraman, Krishnan

    Natural fibre reinforced thermoplastic composites find a wide array of applications in the automobile, building and construction industries. These composites are mostly produced by injection moulding or extrusion through properly designed dies. During these production processes, the shear forces exerted by the screw or ram leads to the degradation of the natural fibres. A screwless extruder that minimises fibre degradation and employs a reliable and low technology process has already been developed. However, the fibre degradation caused by the screwless extruder has not been compared with that of the conventional extruders. So, this study is focused on the influence of extrusion processes on the degradation of natural fibres in thermoplastic composites. Sisal fibres of 10 mm length were extruded with polypropylene, to furnish extrudates with a fibre mass fraction of 25%, using conventional single screw and screwless extruders. Polypropylene in the extrudates was dissolved in Xylene in a Sohxlet process; the fibres that were extracted were analysed for length variations. While fibre degradation in the form of fibre length variation is similar in both cases, this can be minimised in screwless extrusion by extending the gap between the front face of the cone and the orifice plate.

  13. Design Basis for Fibre Reinforced Concrete (FRC) Pavements

    DEFF Research Database (Denmark)

    Bendixen, Søren; Stang, Henrik

    1996-01-01

    opening relationship can beused to descibe the properties of fibre reinforced concrete (FRC) intension and how the stress-crack opening relationship can beapplied in a simple design scheme for pavements. The projectincludes development of design tools, experiments to determine thestress-crack opening......The paper summarises a Ph.D. project on development of a new design basis for fibre reinforced concrete ground slabs. The stress-crack openingrelationship is a well know basic material property of theso-called fictitious crack model for concrete. In the presentstudy it is shown how the stress-crack...

  14. Seismic Behaviour of Composite Steel Fibre Reinforced Concrete Shear Walls

    Science.gov (United States)

    Boita, Ioana-Emanuela; Dan, Daniel; Stoian, Valeriu

    2017-10-01

    In this paper is presented an experimental study conducted at the “Politehnica” University of Timisoara, Romania. This study provides results from a comprehensive experimental investigation on the behaviour of composite steel fibre reinforced concrete shear walls (CSFRCW) with partially or totally encased profiles. Two experimental composite steel fibre reinforced concrete walls (CSFRCW) and, as a reference specimen, a typical reinforced concrete shear wall (RCW), (without structural reinforcement), were fabricated and tested under constant vertical load and quasi-static reversed cyclic lateral loads, in displacement control. The tests were performed until failure. The tested specimens were designed as 1:3 scale steel-concrete composite elements, representing a three storeys and one bay element from the base of a lateral resisting system made by shear walls. Configuration/arrangement of steel profiles in cross section were varied within the specimens. The main objective of this research consisted in identifying innovative solutions for composite steel-concrete shear walls with enhanced performance, as steel fibre reinforced concrete which was used in order to replace traditional reinforced concrete. A first conclusion was that replacing traditional reinforcement with steel fibre changes the failure mode of the elements, as from a flexural mode, in case of element RCW, to a shear failure mode for CSFRCW. The maximum lateral force had almost similar values but test results indicated an improvement in cracking response, and a decrease in ductility. The addition of steel fibres in the concrete mixture can lead to an increase of the initial cracking force, and can change the sudden opening of a crack in a more stable process.

  15. Vibrated and self-compacting fibre reinforced concrete: experimental investigation on the fibre orientation

    Science.gov (United States)

    Conforti, A.; Plizzari, G. A.; Zerbino, R.

    2017-09-01

    In addition to the fibre type and content, the residual properties of fibre reinforced concrete are influenced by fibre orientation. Consequently, the performance fibre reinforced concrete can be affected by its fresh properties (workability, flowing capacity) and by casting and compaction processes adopted. This paper focuses on the study of the orientation of steel or macro-synthetic fibres in two materials characterized by very different fresh properties: vibrated and self-compacting concrete. Four rectangular slabs 1800 mm long, 925 mm wide and 100 mm high were produced changing concrete and fibre type. From each slab, eighteen small prisms (550 mm long) were firstly cut either orthogonal or parallel to casting direction and, secondly, notched and tested in bending according to EN 14651. Experimental results showed that the toughness properties of a thin slab significantly varies both in vibrated and self-compacting concrete, even if in case of self-compacting concrete this variation resulted higher. Steel fibres led to greater variability of results compared to polymer one, underlining a different fibre orientation. A discussion on the relative residual capacity measured on the prisms sawn from the slabs and the parameters obtained from standard specimens is performed.

  16. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Nielsen, Laila

    1997-01-01

    (capillary water uptake) is used, involving an in-situ method and a laboratory method. Three different concrete qualities as well as steel fibres (ZP) and polypropylene fibres (PP) are used. Results of the durability tests on cracked FRC-beams are compared to results for uncracked FRC-beams and beams without......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by exposing beams to il-point bending until a predefined crack width is reached, using a newly developed test setup. As environmental load, exposure to water...

  17. Corrosion performance of epoxy-coated reinforcement in aggressive environments

    Science.gov (United States)

    Vaca Cortes, Enrique

    The objective of this research was to investigate the integrity and corrosion performance of epoxy-coated reinforcement in aggressive environments. A series of experimental studies were conducted: (a) hot water immersion and knife adhesion testing for assessment of coating adhesion; (b) materials and procedures for repairing coating damage; (c) degree of mechanical damage caused during concrete placement when using metal head and rubber head vibrators; (d) accelerated corrosion of coated bars embedded in macrocell and beam specimens placed in a corrosive environment for more than four years. The effects of coating condition and amount of damage, repaired vs. unrepaired damage, bar fabrication, and concrete cracking were studied. Regardless of coating condition, the performance of epoxy-coated bars was better than that of uncoated bars. Unlike black bars, coated bars did not exhibit deep pitting or substantial loss of cross section at crack locations. Damage to epoxy coating was the most significant factor affecting corrosion performance. Bars with coating in good condition, without any visible damage, performed best. The greater the size and frequency of damage, the more severe and extensive the amount of corrosion. The performance of bars that were fabricated or bent after coating was worse than that of coated straight bars. Mixing coated and uncoated bars in the same concrete member led to undesirable performance. Patching damaged coating reduced but did not prevent corrosion, particularly at bar ends. The most important factor in coating repair was the type and properties of the patching material. Surface preparation prior to coating had little effect. The absence of cracks in the concrete delayed, but did not prevent the onset of corrosion of coated bars. During consolidation of concrete, rubber head vibrators caused less damage to epoxy-coated reinforcement than did comparable metal heads. Hot water and adhesion tests were useful and practical for evaluating

  18. The effect of fibre loading and graphene on the mechanical properties of goat hair fibre epoxy composite

    Science.gov (United States)

    Jayaseelan, J.; Vijayakumar, K. R.; Ethiraj, N.; Sivabalan, T.; nallayan, W. Andrew

    2017-12-01

    Composite materials are heterogenous materials containing one or more solid phases. In recent years cost-effective composite making is an ideal task. Hence we have come out with a natural fibre composite, which contains goat hair and epoxy as a binding element, with the combination of Graphene as a main source of enhanced mechanical property. Fabrication of natural composite consists of five layers of goat hair sandwiched in epoxy matrix. These composites made are tested for mechanical properties including Tensile strength, Flexural strength, Inter laminar shear and Impact strength. The mechanical properties of the six composite sets are analyzed and reported.

  19. Compressive Failure of Fibre Reinforced Materials

    DEFF Research Database (Denmark)

    Jensen, Henrik Myhre

    2003-01-01

    Compressive failure of uni-directional fibre composites by the kink band mechanism is analysed taking into account effects of residual stresses. Two criteria for determining the strength of the composite material have been investigated: Kink band formation at a bifurcation stress in a composite...

  20. Mechanical properties of SiC long fibre reinforced copper

    Energy Technology Data Exchange (ETDEWEB)

    Brendel, A. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany)], E-mail: Annegret.Brendel@ipp.mpg.de; Paffenholz, V.; Koeck, Th.; Bolt, H. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany)

    2009-04-30

    SiC fibre reinforced copper is a potential novel heat sink material for the divertor of future fusion reactors to reinforce the zone between plasma facing material (W) and heat sink material (CuCrZr). The metal matrix composite (MMC) should be able to withstand heat loads up to 15 MW/m{sup 2} at operating temperatures of up to 550 deg. C. SCS6 fibres were coated by magnetron sputtering with a titanium interlayer and the copper matrix was deposited by electroplating. The composite was consolidated by hot-isostatic pressing. The average ultimate tensile strength of composite samples with 20% fibre reinforcement is 640 MPa and for the Young's modulus 162 GPa was determined. The Young's modulus decreases with increasing temperature and reaches 113 GPa at 550 deg. C. Fracture area analysis after tensile tests show the failure of the SCS 6 fibres at the interface between the two outer carbon layers. Titanium as interlayer led to an improved bonding between the outer carbon coating of the SiC fibres and the copper matrix.

  1. Effect of the loading rate on fibre reinforced concrete beams

    Science.gov (United States)

    Juhász, K. P.; Schaul, P.; Nagy, L.

    2017-09-01

    Fibre reinforced concrete has become a widely used material since the end of the 20th century. The uniformly distributed steel or macro synthetic fibres in the concrete structures can give the concrete a residual flexural strength after the first cracks. The different behaviour of materials subjected to different loading rates is a well-known phenomenon, both with steel, synthetic and concrete materials. Standards usually present a recommendation for the loading speed in for different tests. Concrete elements show higher performance due to the high speed of loading or impact loads, their fracture energy and therefore their overall capacity appears greater than the specimens loaded at standard speeds. Fibre reinforced concrete structures are widely used in tramlines and railways, where the speed of the loading is high and therefore of impact by nature. It is important to know what the effect of this high speed loading is for fibre reinforced concrete structures: do these structures have additional capacity, or has the designer overestimated their performance? This article will present an investigation into the effect of the loading rate on case of using fibres with different materials in concrete beams.

  2. safety of carbon fibre reinforced plastic hollow sections in compression

    African Journals Online (AJOL)

    ADMINUSER

    2014-01-06

    Jan 6, 2014 ... much stiffer and corrosion resistant. There is, however, some hesitation among the engineering community about using these new materials until more real life evaluations have been done. A number of researchers have demonstrated that carbon fibre reinforced polymer (CFRP) materials can be used to ...

  3. simulation models for presiction of structrual fibre-reinforced come

    African Journals Online (AJOL)

    user

    the analysis and design of palmnut fibre-reinforced cement composites. 1.0 INTRODUCTION ... associated with the use of some of these materials. For example, asbestos dust from asbestos cement sheets results in health hazards such as asbestosis and mesothelioma. In a bid .... F-statistic test was also conducted and the ...

  4. Mechanical property analysis of kenaf–glass fibre reinforced ...

    Indian Academy of Sciences (India)

    Department of Mechanical Engineering, Sri Sai Ram Engineering College, Chennai 600 044, Tamil Nadu, India. MS received 29 June 2015; accepted 29 ... contributes to a healthier environment [13]. Kenaf fibre is a good reinforcement ..... From the figure, it is observed that there is the grad- ual increase in the displacement, ...

  5. Structural Glass Beams with Embedded Glass Fibre Reinforcement

    NARCIS (Netherlands)

    Louter, P.C.; Leung, Calvin; Kolstein, M.H.; Vambersky, J.N.J.A.; Bos, Freek; Louter, Pieter Christiaan; Veer, Fred

    2010-01-01

    This paper investigates the possibilities of pultruded glass fibre rods as embedded reinforcement in SentryGlas (SG) laminated glass beams. To do so, a series of pullout tests, to investigate the bond strength of the rods to the laminate, and a series of beam tests, to investigate the post-breakage

  6. Fabrication and characterization of S. cilliare fibre reinforced ...

    Indian Academy of Sciences (India)

    In the recent times, there has been an ever-increasing interest in green composite materials for its applications in the field of industries, aerospace, sports, household etc and in many other fields. In this paper, fabrication of Saccharum cilliare fibre reinforced green polymer composites using resorcinol formaldehyde (RF) as ...

  7. The extrinsic influence of carbon fibre reinforced plastic laminates to ...

    Indian Academy of Sciences (India)

    Abstract. The intrinsic advantages of strengthening the steel-based structures by the use of fibre reinforced plastic (FRP) material have not yet been fully exploited. In this paper, a succinct overview of recent studies made to enhance the strength of steel beams using FRP laminates is presented. The results presented and ...

  8. Drilling analysis of coir–fibre-reinforced polyester composites

    Indian Academy of Sciences (India)

    Administrator

    The short coir–fibre-reinforced composites exhibited the tensile, flexural and impact strength of. 16\\1709 MPa, 29\\2611 MPa and ... ties such as tensile strength, flexural strength and impact strength, and their work was limited from .... design of all information-gathering exercises where varia- tion is present, whether under the ...

  9. Fabrication and characterization of S. cilliare fibre reinforced ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. In the recent times, there has been an ever-increasing interest in green composite materials for its applications in the field of industries, aerospace, sports, household etc and in many other fields. In this paper, fabrication of Saccharum cilliare fibre reinforced green polymer composites using resorcinol formaldehyde.

  10. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    In the present communication, a study on the synthesis and mechanical properties of new series of green composites involving Hibiscus sabdariffa fibre as a reinforcing material in urea–formaldehyde (UF) resin based polymer matrix has been reported. Static mechanical properties of randomly oriented intimately mixed ...

  11. Impact fatigue behaviour of carbon fibre-reinforced vinylester resin

    Indian Academy of Sciences (India)

    Two types of unidirectional carbon fibre, one of high strength (DHMS) and another of medium strength (VLMS) reinforced vinylester resin composites have been examined for their impact fatigue behaviour over 104 impact cycles for the first time. The study was conducted using a pendulum type repeated impact apparatus ...

  12. Finite element modelling of fibre-reinforced brittle materials

    NARCIS (Netherlands)

    Kullaa, J.

    1997-01-01

    The tensile constitutive behaviour of fibre-reinforced brittle materials can be extended to two or three dimensions by using the finite element method with crack models. The three approaches in this study include the smeared and discrete crack concepts and a multi-surface plasticity model. The

  13. Fabrication and characterization of S. cilliare fibre reinforced

    Indian Academy of Sciences (India)

    In the recent times, there has been an ever-increasing interest in green composite materials for its applications in the field of industries, aerospace, sports, household etc and in many other fields. In this paper, fabrication of Saccharum cilliare fibre reinforced green polymer composites using resorcinol formaldehyde (RF) as ...

  14. Synthesis of carbon fibre-reinforced, silicon carbide composites by ...

    Indian Academy of Sciences (India)

    Verrilli M J, Opila E J, Calomino A and Kiser J D 2004 Effect of environment on the stress–rupture behavior of a carbon-fibre-reinforced silicon carbide ceramic matrix composite, J. Am. Ceram. Soc. 87(8): 1536–. 1542. Zhang Q and Li G 2009 A review of the application of C/SiC composites in thermal protection system,.

  15. Fabrication and characterization of S. cilliare fibre reinforced ...

    Indian Academy of Sciences (India)

    Administrator

    Keeping in view the eco-friendly advantages of green materials a large number of ... polymer composites (Singha et al 2008a, b). Keeping in view the easy availability and many other ecofriendly advantages, we have used this fibre as reinforcing mate-. *Author for ..... 3.3c Flexural strength: Similar trends as obtained in.

  16. Surface waves in fibre-reinforced anisotropic elastic media

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    MS received 1 March 2002. Abstract. In the paper under discussion, the problem of surface waves in fibre- reinforced anisotropic elastic media has been studied. The authors express the plane strain displacement components in terms of two scalar potentials to decouple the plane motion into P and SV waves. In the present ...

  17. Impact fatigue behaviour of carbon fibre-reinforced vinylester resin ...

    Indian Academy of Sciences (India)

    Two types of unidirectional carbon fibre, one of high strength (DHMS) and another of medium strength (VLMS) reinforced vinylester resin composites have been examined ... Department of Materials Science, Indian Association for the Cultivation of Science, 2A & B, Raja SC Mallick Road, Calcutta 700 032, India; Indian Jute ...

  18. Tensile Strength of Epoxy Composites Reinforced with Fique Fibers

    Science.gov (United States)

    Altoé, Giulio Rodrigues; Netto, Pedro Amoy; Teles, Maria Carolina Andrade; Borges, Luiz Gustavo Xavier; Margem, Frederico Muylaert; Monteiro, Sergio Neves

    Environmentally friendly composites, made from natural fibers, are among the most investigated and applied today. Natural fibers have showed advantages, such as, flexibility and toughness, if compared with synthetic fibers. This work investigates the tensile strength of epoxy composites reinforced with Fique fibers. The Fique fiber was extracted from Fique leaf presents some significant characteristic, but until now only few studies on Fique fiber were performed. Composites reinforced with up to 30% in volume of long, continuous and aligned Fique fibers were tested in an Instron machine at room temperature. The incorporation of Fique fibers increases the tensile strength of the composite. After fracture the specimens were analyzed by a SEM (scanning electron microscope).

  19. Improvement of the piezoelectric properties of glass fiber-reinforced epoxy composites by poling treatment

    International Nuclear Information System (INIS)

    Oh, S M; Hwang, H Y

    2013-01-01

    Recently, a new non-destructive method has been proposed for damage monitoring of glass fiber-reinforced polymer composite materials using the piezoelectric characteristics of a polymeric matrix. Several studies of the piezoelectric properties of unidirectional glass fiber epoxy composites and damage monitoring of double-cantilever beams have supported the claim that the piezoelectric method is feasible and powerful enough to monitor the damage of glass fiber epoxy composites. Generally, conventional piezoelectric materials have higher piezoelectric characteristics through poling treatment. In this work, we investigated the change of the piezoelectric properties of glass fiber-reinforced epoxy composites before and after poling treatment. The piezoelectric constants (d 33 ) of glass fiber-reinforced epoxy composites increased by more than 400%. Also, x-ray diffraction tests revealed that poling treatment changed the degree of crystallinity of the epoxy matrix, and this led to the improvement of the piezoelectric characteristics of glass fiber-reinforced epoxy composites. (paper)

  20. Investigations on d.c. conductivity behaviour of milled carbon fibre ...

    Indian Academy of Sciences (India)

    This paper reports the d.c. conductivity behaviour of milled carbon fibre reinforced polysulphide modified epoxy gradient composites. Milled carbon fibre reinforced composites having 3 vol. % of milled carbon fibre and poly sulphide modified epoxy resin have been developed. D.C. conductivity measurements are conducted ...

  1. Experimental investigation on bond of reinforcement in steel fibre-reinforced lightweight concrete

    Science.gov (United States)

    Holschemacher, K.; Ali, A.

    2017-10-01

    Bond behaviour of reinforcement is crucial parameter for load bearing reinforced concrete members. Many parameters like anchorage of reinforcement, lap splices, deflection or tension stiffening are influenced by the bond properties. It is well known that the ductility of bond can be improved by steel fibres. In this context almost innumerable experiments were performed for investigation of bond in normal weight concrete. However, the bond behaviour of reinforcement in steel fibre-reinforced lightweight concrete (SFRLWC) has received much less attention. For this reason, an experimental program dealing with bond in SFRLWC has been started at HTWK Leipzig/Germany. Main parts of the investigation were pull-out tests with various bar sizes and application of different steel fibre-reinforced lightweight and normal weight concretes. The paper reports the details of experimental investigations and evaluates the test results. As one of the most important outcomes that can be noted is that there is pronounced effect of bar size and steel fibre amount on bond properties in general. But those effects are more pronounced for SFRLWC in comparison to normal weight concrete with and without steel fibres.

  2. The influence of stiffeners on axial crushing of glass-fabric-reinforced epoxy composite shells

    Directory of Open Access Journals (Sweden)

    A. Vasanthanathan

    2017-01-01

    Full Text Available A generic static and impact experimental procedure has been developed in this work aimed at improving the stability of glass fabric reinforced epoxy shell structures by bonding with axial stiffeners. Crashworthy structures fabricated from composite laminate with stiffeners would offer energy absorption superior to metallic structures under compressive loading situations. An experimental material characterisation of the glass fabric reinforced epoxy composite under uni-axial tension has been carried out in this study. This work provides a numerical simulation procedure to describe the static and dynamic response of unstiffened glass fabric reinforced epoxy composite shell (without stiffeners and stiffened glass fabric reinforced epoxy composite shell (with axial stiffeners under static and impact loading using the Finite Element Method. The finite element calculation for the present study was made with ANSYS®-LS-DYNA® software. Based upon the experimental and numerical investigations, it has been asserted that glass fabric reinforced epoxy shells stiffened with GFRP stiffeners are better than unstiffened glass fabric reinforced epoxy shell and glass fabric reinforced epoxy shell stiffened with aluminium stiffeners. The failure surfaces of the glass fabric reinforced epoxy composite shell structures tested under impact were examined by SEM.

  3. Effect of pectin and hemicellulose removal from hemp fibres on the mechanical properties of unidirectional hemp/epoxy composites

    DEFF Research Database (Denmark)

    Liu, Ming; Meyer, Anne S.; Fernando, Dinesh

    2016-01-01

    The objective of this study was to investigate the effect of pectin and hemicellulose removal from hemp fibres on the mechanical properties of hemp fibre/epoxy composites. Pectin removal by EDTA and endo-polygalacturonase (EPG) removed epidermal and parenchyma cells from hemp fibres and improved...

  4. Strengthening Techniques of RC Columns Using Fibre Reinforced Polymeric Materials

    Directory of Open Access Journals (Sweden)

    Ciprian Cozmanciuc

    2009-01-01

    Full Text Available Fibre reinforced composite materials are becoming more frequently used in civil engineering structures. One of the most practical applications of these new materials concerns the strengthening of reinforced concrete columns by means of confinement with fibre composite sheets. In the literature, various theoretical models have been proposed to describe the behaviour of confined concrete columns. The principal advantages of this technique are the high strength-to-weight ratio, good fatigue properties, non-corroding characteristics of the fibre reinforced polymers (FRP, and the facility of its application. The maximum efficiency of confining systems using FRP materials is reached in case of columns with circular cross-section and is explained by the fact that the entire section of the column is involved into the confinement effect. Rectangular confining reinforcement is less efficient as the confinement action is mostly located at the corners This paper reveals the most utilized techniques of performing composite confining systems for reinforced concrete columns, with their advantages and also disadvantages.

  5. Quantification of cracking localization in fibre-reinforced concrete beams

    Science.gov (United States)

    Werzbrger, S.; Karinski, Y. S.; Dancygier, A. N.

    2017-09-01

    The paper presents an analysis of cracking localization in beams made of fibre-reinforced concrete with conventional reinforcement. This phenomenon has been quantified by the ratio m/n between the number of the significantly wide cracks and the total number of flexural cracks that developed within the constant moment zone of the beams. It is shown that beams with larger reinforcement ratio had larger values of m/n, that is, lower cracking localization. For the given concrete mix, when the reinforcement ratios ρ were larger than ∼2% cracking localization was diminished. Furthermore, for low values of ρ, m/n ratios of the specimens with lower fibre contents are somewhat larger than those of the specimens with larger content. It is also shown that as the reinforcement ratio decreases below ∼0.5% the normalized mid-span ultimate deflections decreases as well, which corresponds with the observation of the cracking localization phenomenon for low reinforcement ratios. For larger reinforcement ratio, when m/n increases above ∼0.6, there is no effect of cracking localization on the ultimate deflection. Moreover, in this range of r the values of d are ≳ 1.0, as commonly expected for RFC structural elements. It is noted that the ultimate deflection of the beams corresponds to their flexural ductility.

  6. Rheological characteristics of pulp-fibre-reinforced polyamide composite

    Science.gov (United States)

    Cherizol, Robenson

    Recently, there has been increasing interest in utilizing pulp-fibre-reinforced, higher-melting-temperature engineering thermoplastics, such as polyamide 11 and polyamide 6 in the automotive, aerospace and construction industries. Moreover, the rheological characteristics of those composites were not fully investigated in relation to processing approaches and pulp-fibre aspect ratio. Two processing approaches were used in this thesis: the extrusion compounding process and the Brabender mixer technique using inorganic salt lithium chloride (LiCl). The fibre-length distribution and content, and the densities of the PA11 and modified bio-based PA11 after compounding, were investigated and found to coincide with the final properties of the resultant composites. The effects of fibre content, fibre aspect ratio, and fibre length on rheological properties were studied. The rheological properties of high-yield-pulp (HYP) -reinforced bio-based Polyamide 11 (PA11) composite (HYP/PA11) were experimentally investigated using a capillary rheometer. Experimental test results showed a steep decrease in shear viscosity with increasing shear rate; this melt-flow characteristic corresponds to shear-thinning behavior in HYP/PA11. The morphological properties of HYP/PA11 composite were examined using SEM: no fibre pullout was observed. This was due to the presence of the hydrogen bond, which created excellent compatibility between high-yield pulp fibre and bio-based Nylon 11. The viscoelastic characteristics of biocomposites derived from natural-fibre-reinforced thermoplastic polymers and of predictive models were reviewed to understand their rheological behavior. Novel predicted multiphase rheological-model-based polymer, fibre, and interphasial phases were developed. Rheological characteristics of the composite components influenced the development of resultant microstructures; this in turn affected the mechanical characteristics of a multiphase composite. Experimental and

  7. Characterisation of the mechanical and fracture properties of a uni-weave carbon fibre/epoxy non-crimp fabric composite

    Directory of Open Access Journals (Sweden)

    Thomas Bru

    2016-03-01

    Full Text Available A complete database of the mechanical properties of an epoxy polymer reinforced with uni-weave carbon fibre non-crimp fabric (NCF is established. In-plane and through-the-thickness tests were performed on unidirectional laminates under normal loading and shear loading. The response under cyclic shear loading was also measured. The material has been characterised in terms of stiffness, strength, and failure features for the different loading cases. The critical energy release rates associated with different failure modes in the material were measured from interlaminar and translaminar fracture toughness tests. The stress–strain data of the tensile, compressive, and shear test specimens are included. The load–deflection data for all fracture toughness tests are also included. The database can be used in the development and validation of analytical and numerical models of fibre reinforced plastics (FRPs, in particular FRPs with NCF reinforcements.

  8. Effect of Steel Fibres Distribution on Impact Resistance Performance of Steel Fibre Reinforced Concrete (SFRC)

    Science.gov (United States)

    Che Muda, Zakaria; Liyana Mohd Kamal, Nur; Syamsir, Agusril; Shao Yang, Chen; Beddu, Salmia; Nasharuddin Mustapha, Kamal; Thiruchelvam, Sivadass; Usman, Fathoni; Itam, Zarina; Ashraful Alam, Md; Birima, Ahmed H.; Zaroog, O. S.

    2016-03-01

    This paper investigate the effect of the mesh distribution on the impact performance of steel fibre reinforced concrete (SFRC) for the concrete slab of 300mm × 300mm size reinforced with varied thickness and fraction volume subjected to low impact projectile test. A self-fabricated drop-weight impact test rig with a steel ball weight of 1.236 kg drop at 0.57 m height has been used in this research work. The objective of this research is to study the effect of the mesh distribution on the impact resistance SFRC for various slab thickness and fraction volume. Random fibre distribution is the more effective than the top and bottom fibre distribution in terms of absorption of impact energy, crack resistance, the ability to control crack formation and propagation against impact energy.

  9. Corrosion resistance of steel fibre reinforced concrete - A literature review

    DEFF Research Database (Denmark)

    Marcos Meson, Victor; Michel, Alexander; Solgaard, Anders

    2017-01-01

    Steel fibre reinforced concrete (SFRC) is increasingly being used in the construction of civil infrastructure. However, there are inconsistencies among international standards and guidelines regarding the consideration of carbon-steel fibres for the structural verification of SFRC exposed...... an overall agreement among academics and regulators regarding the durability of uncracked SFRC exposed to chlorides and carbonation. Contrariwise, the durability of cracked SFRC is under discussion at the technical and scientific level, as there is a large dispersion on the experimental results and some...

  10. Effect of fibre content and alkali treatment on mechanical properties ...

    Indian Academy of Sciences (India)

    Roystonea regia fibre; epoxy resin; alkali treatment; mechanical properties. Abstract. The present paper investigates the effect of fibre content and alkali treatment on tensile, flexural and impact properties of unidirectional Roystonea regia natural-fibre-reinforced epoxy composites which are partially biodegradable.

  11. Glass fibre reinforced acrylic resin complete dentures: a 5-year clinical study.

    Science.gov (United States)

    Goguţă, Luciana Maria; Bratu, Dorin; Jivănescu, Anca; Erimescu, Raluca; Mărcăuţeanu, Corina

    2012-03-01

    The aim of the study was to establish the wear resistance of the glass fiber reinforced complete dentures comparative to the traditional acrylic complete dentures. Complete new dentures were made to replace old fractured 'un'-reinforced acrylic dentures. The total number of dentures was 30 and woven E-glass fibre reinforcements were used in maxillary complete dentures. Unidirectional E-glass fibre reinforcements were used as partial fibre reinforcements in mandibular complete dentures. Ten complete acrylic un-reinforced dentures were used as control. The follow-up period was 5 years and the recalls were made at 6 months. After 5 years of wearing the new dentures, the control dentures suffered seven fractures. After 5 years all the mandibular reinforced dentures were in good shape. The maxillary complete reinforced dentures suffered four partial fractures. Fracture lines were restricted by the glass fibre net and the patients could still use their dentures. Pre-impregnated E-glass fibre nets and polymer pre-impregnated E-glass unidirectional fibres are useful in reinforcing acrylic resin complete dentures especially were heavy occlusal forces are involved. Glass fibre reinforcement will be applied on the tension side in both cases (total fibre reinforcement and partial fibre reinforcement). The reinforcement cannot replace the necessary linings and occlusal adjustments. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  12. Tungsten fibre-reinforced composites for advanced plasma facing components

    Directory of Open Access Journals (Sweden)

    R. Neu

    2017-08-01

    Full Text Available The European Fusion Roadmap foresees water cooled plasma facing components in a first DEMO design in order to provide enough margin for the cooling capacity and to only moderately extrapolate the technology which was developed and tested for ITER. In order to make best use of the water cooling concept copper (Cu and copper-chromium-zirconium alloy (CuCrZr are envisaged as heat sink whereas as armour tungsten (W based materials will be used. Combining both materials in a high heat flux component asks for an increase of their operational range towards higher temperature in case of Cu/CuCrZr and lower temperatures for W. A remedy for both issues- brittleness of W and degrading strength of CuCrZr- could be the use of W fibres (Wf in W and Cu based composites. Fibre preforms could be manufactured with industrially viable textile techniques. Flat textiles with a combination of 150/70 µm W wires have been chosen for layered deposition of tungsten-fibre reinforced tungsten (Wf/W samples and tubular multi-layered braidings with W wire thickness of 50 µm were produced as a preform for tungsten-fibre reinforced copper (Wf /Cu tubes. Cu melt infiltration was performed together with an industrial partner resulting in sample tubes without any blowholes. Property estimation by mean field homogenisation predicts strongly enhanced strength of the Wf/CuCrZr composite compared to its pure CuCrZr counterpart. Wf /W composites show very high toughness and damage tolerance even at room temperature. Cyclic load tests reveal that the extrinsic toughening mechanisms counteracting the crack growth are active and stable. FEM simulations of the Wf/W composite suggest that the influence of fibre debonding, which is an integral part of the toughening mechanisms, and reduced thermal conductivity of the fibre due to the necessary interlayers do not strongly influence the thermal properties of future components.

  13. Glass Reinforcement of Various Epoxy Resins-Polyurea Systems

    Science.gov (United States)

    Joshi, Medha; Jauhari, Smita

    2012-07-01

    Polyureas (PUs) were prepared by the polycondensation reaction of disperse dyes containing -NH2 group and toluene 2, 4-diisocyanate. The disperse dyes have been prepared by coupling of various 2-diazobenzothiazoles with 1,3-benzenediamine. All the PUs were characterized by elemental analysis, spectral studies, number average molecular weight ( {overline{{Mn}} } ), and thermogravimetry. Further reaction of PUs was carried out with an epoxy resin (i.e., DGEBA). The curing study of prepared resins was monitored by differential scanning calorimeter (DSC). Based on DSC, thermograms glass fiber-reinforced composites have been laminated and characterized by chemical, mechanical, and electrical properties. The unreinforced cured resins were subjected to thermogravimetric analysis (TGA). The laminated composites showed excellent resistance properties against chemicals and good mechanical and electrical properties.

  14. A viscoelastic-viscoplastic model for short-fibre reinforced polymers with complex fibre orientations

    Directory of Open Access Journals (Sweden)

    Nciri M.

    2015-01-01

    Full Text Available This paper presents an innovative approach for the modelling of viscous behaviour of short-fibre reinforced composites (SFRC with complex distributions of fibre orientations and for a wide range of strain rates. As an alternative to more complex homogenisation methods, the model is based on an additive decomposition of the state potential for the computation of composite’s macroscopic behaviour. Thus, the composite material is seen as the assembly of a matrix medium and several linear elastic fibre media. The division of short fibres into several families means that complex distributions of orientation or random orientation can be easily modelled. The matrix behaviour is strain-rate sensitive, i.e. viscoelastic and/or viscoplastic. Viscoelastic constitutive laws are based on a generalised linear Maxwell model and the modelling of the viscoplasticity is based on an overstress approach. The model is tested for the case of a polypropylene reinforced with short-glass fibres with distributed orientations and subjected to uniaxial tensile tests, in different loading directions and under different strain rates. Results demonstrate the efficiency of the model over a wide range of strain rates.

  15. Processing, structure and flexural strength of CNT and carbon fibre ...

    Indian Academy of Sciences (India)

    Administrator

    Epoxy composites; carbon fibre; CNT; hand lay-up technique; unidirectional weaving; micro- ... CNT reinforced, epoxy matrix hybrid composite is evalu- ... of the epoxy resin) of diethyl toluene diamine (DETDA) hardener (industrial designation – LY5200) was mixed to the above epoxy mixture. Dispersion of CNTs was ...

  16. Fracture Resistance Evaluation of Fibre Reinforced Brittle Matrix Composites

    Czech Academy of Sciences Publication Activity Database

    Dlouhý, Ivo; Chlup, Zdeněk

    2005-01-01

    Roč. 290, - (2005), s. 167-174 ISSN 1013-9826. [Fractography of Advanced Ceramic s /2./. Stará Lesná, 03.10.2004-06.10.2004] R&D Projects: GA AV ČR(CZ) IAA2041003; GA ČR(CZ) GA101/02/0683 Keywords : fibre-reinforced ceramic s * glass matrix composites * chevron notch Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.224, year: 2005

  17. Experimental Study on Fibre-reinforced Cementitious Matrix Confined Concrete Columns under Axial Compression

    Directory of Open Access Journals (Sweden)

    Lan Zeng

    2017-03-01

    Full Text Available Poor fire resistance of fibre-reinforced polymer (FRP restricts its further application in construction structures. In this paper, a novel fibre-reinforced cementitious matrix confined concrete column (FRCMCC using fireproof grout as the fibre matrix was developed, and experiments were conducted to establish its performance and analyse the mechanical properties under axial compression. The test results show that its failure mode was more moderate compared to the traditional fibre-reinforced resinous matrix confined concrete column (FRRMCC, and the concrete columns confined with multi-layer fibres and end reinforcement could provide both good strength and ductility.

  18. Rotation capacity of self-compacting steel fibre reinforced concrete beams

    NARCIS (Netherlands)

    Schumacher, P.; Walraven, J.C.; Den Uijl, J.A.; Bigaj-van Vliet, A.

    2009-01-01

    Steel fibres are known to enhance the toughness of concrete in compression and in tension. Steel fibres also improve the bond properties between concrete matrix and reinforcing steel bars. In order to investigate the effect of steel fibres on the rotation capacity of reinforced concrete members,

  19. Woven hybrid composites: Tensile and flexural properties of oil palm-woven jute fibres based epoxy composites

    International Nuclear Information System (INIS)

    Jawaid, M.; Abdul Khalil, H.P.S.; Abu Bakar, A.

    2011-01-01

    Highlights: → Woven hybrid composites show good tensile and flexural properties. → Hybridization with 20% woven jute gives rise to sufficient modulus to composites. → Layering pattern affect mechanical properties of hybrid composites. → Statistical analysis shows that there is significant difference between composites. - Abstract: In this research, tensile and flexural performance of tri layer oil palm empty fruit bunches (EFB)/woven jute (Jw) fibre reinforced epoxy hybrid composites subjected to layering pattern has been experimentally investigated. Sandwich composites were fabricated by hand lay-up technique in a mould and cured with 105 deg. C temperatures for 1 h by using hot press. Pure EFB and woven jute composites were also fabricate for comparison purpose. Results showed that tensile and flexural properties of pure EFB composite can be improved by hybridization with woven jute fibre as extreme woven jute fibre mat. It was found that tensile and flexural properties of hybrid composite is higher than that of EFB composite but less than woven jute composite. Statistical analysis of composites done by ANOVA-one way, it showed significant differences between the results obtained. The fracture surface morphology of the tensile samples of the hybrid composites was performed by using scanning electron microscopy.

  20. Finite Element Analysis of Drilling of Carbon Fibre Reinforced Composites

    Science.gov (United States)

    Isbilir, Ozden; Ghassemieh, Elaheh

    2012-06-01

    Despite the increased applications of the composite materials in aerospace due to their exceptional physical and mechanical properties, the machining of composites remains a challenge. Fibre reinforced laminated composites are prone to different damages during machining process such as delamination, fibre pull-out, microcracks, thermal damages. Optimization of the drilling process parameters can reduces the probability of these damages. In the current research, a 3D finite element (FE) model is developed of the process of drilling in the carbon fibre reinforced composite (CFC). The FE model is used to investigate the effects of cutting speed and feed rate on thrust force, torque and delamination in the drilling of carbon fiber reinforced laminated composite. A mesoscale FE model taking into account of the different oriented plies and interfaces has been proposed to predict different damage modes in the plies and delamination. For validation purposes, experimental drilling tests have been performed and compared to the results of the finite element analysis. Using Matlab a digital image analysis code has been developed to assess the delamination factor produced in CFC as a result of drilling.

  1. Modelling of volumetric composition and mechanical properties of unidirectional hemp/epoxy composites - Effect of enzymatic fibre treatment

    DEFF Research Database (Denmark)

    Liu, Ming; Thygesen, Anders; Meyer, Anne S.

    2016-01-01

    The objective of the present study is to assess the effect of enzymatic fibre treatments on the fibre performance in unidirectional hemp/epoxy composites by modelling the volumetric composition and mechanical properties of the composites. It is shown that the applied models can well predict...... the changes in volumetric composition and mechanical properties of the composites when differently treated hemp fibres are used. The decrease in the fibre correlated porosity factor with the enzymatic fibre treatments shows that the removal of pectin by pectinolytic enzymes results in a better fibre...

  2. Crack Growth Monitoring by Embedded Optical Fibre Bragg Grating Sensors: Fibre Reinforced Plastic Crack Growing Detection

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to asses a crack growing/damage event in fibre reinforced plastic, or adhesive using Fibre Bragg Grating (FBG) sensors embedded in a host material. Different features of the crack mechanism that induce a change in the FBG response were identified. Double...... caused by the crack, and to correlate with the FBG sensor. A Material-Sensor model was developed in order to predict the sensor output response under a crack/delamination situation, which can be used as an analysis tool for future application of this measurement technology in more complex structures....

  3. Cytotoxicity of coated and uncoated fibre-reinforced composites.

    Science.gov (United States)

    Frese, Cornelia; Wolff, Diana; Zingler, Sebastian; Krueger, Tanja; Stucke, Kathrin; Lux, Christopher J; Staehle, Hans Joerg; Erber, Ralf

    2014-07-01

    Currently, there are many fibre-reinforced composites (FRCs) available which differ in the type and volume fraction of fibres, pre-treatment of fibres and matrix composition. The aims of this in vitro investigation were to determine whether there is a difference in biocompatibility of FRCs and if coating FRCs with resin composites influences their cytotoxic potential. Five different FRC materials were tested which were either uncoated or coated with flowable or viscous resin composite. Artificial saliva extracts were prepared according to USP-XXIII and ISO-10993 to determine cytotoxicity by testing cell viability and growth of primary human gingival fibroblasts (HGF) using MTT assay, LIVE/DEAD(®) assay and cell proliferation assay. The influence of eluates on fibres of the cytoskeleton was investigated by vimentin, tubulin and actinin immunostainings. A two-way ANOVA followed by Scheffe's post-hoc test, which included the factors FRC material and coating procedure, was performed to assess cytotoxicity. All extracts of FRC materials displayed minor cytotoxic potential on HGF cell viability, cell proliferation and integrity of the cytoskeleton. The type of FRC material significantly influenced cell viability (MTT assay) (p material resulted in altered cell viability. Distribution and organization of cytosolic fibres was not affected after HGF exposure to eluates. There is a lack of knowledge about the leaching behaviour of commonly available fully pre-impregnated FRCs and their interactions with coating materials. The coating of FRCs with resin composite materials did not impact biocompatibility.

  4. Punching Shear in Steel Fibre Reinforced Concrete Slabs Without Traditional Reinforcement

    Science.gov (United States)

    Tan, K. H.; Venkateshwaran, A.

    2017-09-01

    The punching shear capacity of steel fibre reinforced concrete (SFRC) slabs without traditional steel bar reinforcement was investigated by conducting central point-load tests on twelve square slabs. The test parameters covered fibres with different multi-hook ends, concrete compressive strength, reinforcing index and slab thickness. The statistical performance of two existing models for the prediction of punching shear capacity of SFRC slabs without traditional reinforcement was examined. The load carrying capacity of these slabs were also assessed using the yield line theory. It is noted that the slabs failed primarily in flexure and the yield line theory predicted the load carrying capacities of the slabs most accurately. The reason for a flexural failure in SFRC slabs without steel bars is attributed to the lesser energy required in the propagation of an existing flexural cracks than in the creation of a new circumferential cracks around the column face.

  5. RETROFITTING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLYMER (FRP COMPOSITES - A REVIEW

    Directory of Open Access Journals (Sweden)

    Namasivayam Aravind

    2013-01-01

    Full Text Available Rehabilitation and strengthening of old structures using advanced materials is a contemporary research in the field of Structural Engineering. During past two decades, much research has been carried out on shear and flexural strengthening of reinforced concrete beams using different types of fibre reinforced polymers and adhesives. Strengthening of old structures is necessary to obtain an expected life span. Life span of Reinforced Concrete (RC structures may be reduced due to many reasons, such as deterioration of concrete and development of surface cracks due to ingress of chemical agents, improper design and unexpected external lateral loads such as wind or seismic forces acting on a structure, which are also the reasons for failure of structural members. The superior properties of polymer composite materials like high corrosion resistance, high strength, high stiffness, excellent fatigue performance and good resistance to chemical attack etc., has motivated the researchers and practicing engineers to use the polymer composites in the field of rehabilitation of structures. This paper reviews fourteen articles on rehabilitation of reinforced concrete (RC beams. The paper reviews the different properties of Glass Fibre Reinforced Polymer (GFRP and Carbon Fibre Reinforced Polymer (CFRP composites and adhesives, influence of dimensions of beams and loading rate causing failure. The paper proposes an enhanced retrofitting technique for flexural members and to develop a new mathematical model.

  6. RETROFITTING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLYMER (FRP COMPOSITES – A REVIEW

    Directory of Open Access Journals (Sweden)

    Namasivayam Aravind

    2013-06-01

    Full Text Available Rehabilitation and strengthening of old structures using advanced materials is a contemporary research in the field of Structural Engineering. During past two decades, much research has been carried out on shear and flexural strengthening of reinforced concrete beams using different types of fibre reinforced polymers and adhesives. Strengthening of old structures is necessary to obtain an expected life span. Life span of Reinforced Concrete (RC structures may be reduced due to many reasons, such as deterioration of concrete and development of surface cracks due to ingress of chemical agents, improper design and unexpected external lateral loads such as wind or seismic forces acting on a structure, which are also the reasons for failure of structural members. The superior properties of polymer composite materials like high corrosion resistance, high strength, high stiffness, excellent fatigue performance and good resistance to chemical attack etc., has motivated the researchers and practicing engineers to use the polymer composites in the field of rehabilitation of structures. This paper reviews fourteen articles on rehabilitation of reinforced concrete (RC beams. The paper reviews the different properties of Glass Fibre Reinforced Polymer (GFRP and Carbon Fibre Reinforced Polymer (CFRP composites and adhesives, influence of dimensions of beams and loading rate causing failure. The paper proposes an enhanced retrofitting technique for flexural members and to develop a new mathematical model.

  7. Impact Resistance Performance of Kenaf Fibre Reinforced Concrete

    Science.gov (United States)

    Che Muda, Zakaria; Liyana Mohd Kamal, Nur; Syamsir, Agusril; Sheng, Chiam Yung; Beddu, Salmia; Nasharuddin Mustapha, Kamal; Thiruchelvam, Sivadass; Usman, Fathoni; Ashraful Alam, Md; Birima, Ahmed H.; Zaroog, O. S.

    2016-03-01

    This paper investigate the performance of kenaf fibre mesh reinforced concrete (KFMRC) with varied kenaf fibre mesh reinforcement content for the concrete slab of 300mm × 300mm size reinforced with different mesh diameter at constant spacing with varied slab thickness subjected to low impact projectile test. A self-fabricated drop-weight impact test rig with a steel ball weight of 1.236 kg drop at 0.40 m height has been used in this research work. The main variables for the study is to find the relationship of the impact resistance against the amount of mesh reinforcement and slab thickness. A linear relationship has been established between first and ultimate crack resistance against kenaf fiber diameters by the experiment. The linear relationship has also been established between the service (first) crack and ultimate crack resistance against the slab thickness. The threshold (highest) values for service crack and ultimate crack is 47.9 N/mm2 and 130.58 N/mm2 respectively observed and computed for 50 mm slab with 7 mm diameter mesh.

  8. Crack Growth Monitoring by Embedded Optical Fibre Bragg Grating Sensors: Fibre Reinforced Plastic Crack Growing Detection

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to asses a crack growing/damage event in fibre reinforced plastic, or adhesive using Fibre Bragg Grating (FBG) sensors embedded in a host material. Different features of the crack mechanism that induce a change in the FBG response were identified. Double...... Cantilever Beams specimens made with glass fibre glued with structural adhesive, were instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. A digital image correlation technique was used to determine the presence of the specific phenomena...... caused by the crack, and to correlate with the FBG sensor. A Material-Sensor model was developed in order to predict the sensor output response under a crack/delamination situation, which can be used as an analysis tool for future application of this measurement technology in more complex structures....

  9. Application of fibre reinforced plastic sandwich structures for automotive crashworthiness applications

    NARCIS (Netherlands)

    Lukaszewicz, D.; Blok, L.G.; Kratz, J.; Ward, C.; Kassapoglou, C.; Elmarakbi, A.; Araújo, A.L.

    2016-01-01

    In this work the application of fibre reinforced plastic (FRP) sandwich
    structures, with particular focus on aramid fibre tufted sandwiches is being studied for
    automotive crashworthiness applications using impact testing and numerical simulation.

  10. Study of the shear behaviour of fibre reinforced concrete beams

    Directory of Open Access Journals (Sweden)

    Barragán, B.

    2008-12-01

    Full Text Available This study presents a series of tests for characterizing the structural behaviour of fibre reinforced concrete beams subjected to shear loading. The experimental program involves three types of fibres; two steel fibres and a polypropylene fibre. As a reference, plain concrete and conventionally reinforced concrete specimens have also been tested. The ultimate shear capacity of the beams is calculated and these values compared with those predicted by existing formulations. The study confirms that the toughness and shear crack resistance of the material is greatly enhanced by the fibres. However, the incorporation of 1% of fibres yielded lower shear strength than conventionally reinforced beams with the same amount of steel in the form of transversal stirrups. Existing design methods seem sufficiently robust to estimate the maximum shear load, even when using material properties (toughness, tensile strength extrapolated from code formulae.Este trabajo presenta una serie de ensayos para caracterizar el comportamiento estructural de vigas realizadas con hormigón reforzado con fibras sometidas a cortante. El programa de ensayos incluía tres tipos de fibras, dos de acero y una de polipropileno. Asimismo, se realizó una serie de ensayos con una viga confeccionada con hormigón armado convencional. La resistencia a cortante de las vigas es comparada con los valores que la formulación existente predice. El estudio confirma que la tenacidad y la resistencia a cortante son incrementadas tras la adición de fibras al hormigón. Sin embargo, la incorporación de un 1% en volumen de fibras conduce a valores de resistencia última a cortante inferiores a los obtenidos con vigas de hormigón convencional con la misma cantidad de acero dispuesta en forma de cercos de cortante. Los actuales métodos de cálculo parecen lo suficientemente precisos para evaluar la carga de cortante último, incluso cuando los parámetros mecánicos utilizados en las f

  11. Durability of fibre reinforced concrete structures exposed to combined mechanical and environmental load

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Hansen, Kurt Kielsgaard

    1999-01-01

    The main conclusions from a research project on durability of cracked fibre reinforced concrete structures exposed to chlorides, water or freeze-thaw are presented. The effect of fibres and cracks on the durability of concrete is studied.......The main conclusions from a research project on durability of cracked fibre reinforced concrete structures exposed to chlorides, water or freeze-thaw are presented. The effect of fibres and cracks on the durability of concrete is studied....

  12. Development of glass fibre reinforced composites using microwave heating technology

    Science.gov (United States)

    Köhler, T.; Vonberg, K.; Gries, T.; Seide, G.

    2017-10-01

    Fibre reinforced composites are differentiated by the used matrix material (thermoplastic versus duroplastic matrix) and the level of impregnation. Thermoplastic matrix systems get more important due to their suitability for mass production, their good shapeability and their high impact resistance. A challenge in the processing of these materials is the reduction of the melt flow paths of the thermoplastic matrix. The viscosity of molten thermoplastic material is distinctly higher than the viscosity of duroplastic material. An approach to reduce the flow paths of the thermoplastic melt is given by a commingling process. Composites made from commingling hybrid yarns consist of thermoplastic and reinforcing fibres. Fabrics made from these hybrid yarns are heated and consolidated by the use of heat pressing to form so called organic sheets. An innovative heating system is given by microwaves. The advantage of microwave heating is the volumetric heating of the material, where the energy of the electromagnetic radiation is converted into thermal energy inside the material. In this research project microwave active hybrid yarns are produced and examined at the Institute for Textile Technology of RWTH Aachen University (ITA). The industrial research partner Fricke und Mallah Microwave Technology GmbH, Peine, Germany develops an innovative pressing systems based on a microwave heating system. By implementing the designed microwave heating technology into an existing heat pressing process, FRTCs are being manufactured from glass and nanomodified polypropylene fibre woven fabrics. In this paper the composites are investigated for their mechanical and optical properties.

  13. Corrosion protection service life of epoxy-coated reinforcing steel in Virginia bridge decks.

    Science.gov (United States)

    2003-01-01

    The corrosion protection service life extension provided by epoxy-coated reinforcement (ECR) was determined by comparing ECR and bare steel bars from 10 Virginia bridge decks built between 1981 and 1995. The objective was to determine the corrosion p...

  14. Parameters governing the corrosion protection efficiency of fusion-bonded epoxy coatings on reinforcing steel.

    Science.gov (United States)

    2008-01-01

    The purpose of this study was to investigate various epoxy coating and exposure parameters to determine their effects on the corrosion of reinforcing steel. The parameters investigated were: chloride content at the bar depth, coated bar corroded area...

  15. Cellulose Fibre-Reinforced Biofoam for Structural Applications

    Directory of Open Access Journals (Sweden)

    Jasmina Obradovic

    2017-06-01

    Full Text Available Traditionally, polymers and macromolecular components used in the foam industry are mostly derived from petroleum. The current transition to a bio-economy creates demand for the use of more renewable feedstocks. Soybean oil is a vegetable oil, composed mainly of triglycerides, that is suitable material for foam production. In this study, acrylated epoxidized soybean oil and variable amounts of cellulose fibres were used in the production of bio-based foam. The developed macroporous bio-based architectures were characterised by several techniques, including porosity measurements, nanoindentation testing, scanning electron microscopy, and thermogravimetric analysis. It was found that the introduction of cellulose fibres during the foaming process was necessary to create the three-dimensional polymer foams. Using cellulose fibres has potential as a foam stabiliser because it obstructs the drainage of liquid from the film region in these gas-oil interfaces while simultaneously acting as a reinforcing agent in the polymer foam. The resulting foams possessed a porosity of approximately 56%, and the incorporation of cellulose fibres did not affect thermal behaviour. Scanning electron micrographs showed randomly oriented pores with irregular shapes and non-uniform pore size throughout the samples.

  16. Design Fatigue Lives of Polypropylene Fibre Reinforced Polymer Concrete Composites

    Directory of Open Access Journals (Sweden)

    Raman Bedi

    2014-09-01

    Full Text Available Flexural fatigue behavior of Poly-propylene fibre reinforced polymer concrete composites (PFRPCC has been investigated at various stress levels and the statistical analysis of the data thus obtained has been carried out. Polymer Concrete Composite (PCC samples without addition of any type of fibres were also tested for flexural fatigue.  Forty specimens of PCC and One hundred and Forty One specimens of PFRPCC containing 0.5%, 1.0% and 2.0% polypropylene fibres were tested in fatigue using a MTS servo controlled test system. Fatigue life distributions of PCC as well as PFRPCC are observed to approximately follow a two parameter Weibull distribution with correlation coefficient exceeding 0.9. The parameters of the Weibull distribution have been obtained by various methods. Failure probability, which is an important parameter in the fatigue design of materials, has been used to obtain the design fatigue lives for the material. Comparison of design fatigue life of PCC and PFRPCC has been carried out and it is observed that addition of fibres enhances the design fatigue life of PCC.

  17. Connections in Precast Buildings using Ultra High-Strength Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Hansen, Lars Pilegaard

    1995-01-01

    Ultra high-strength concrete adds new dimensions to the design of concrete structures. It is a brittle material but introducing fibres into the matrix changes the material into a highly ductile material. Furthermore, the fibre reinforcement increases the anchorage of traditional reinforcement bars...... and the fire resistance. Such a fibre reinforced ultra high-strength material has been used to develop a simple joint solution between slab elements in a column - slab building system....

  18. Development of fibre reinforced concrete overpacks in France

    International Nuclear Information System (INIS)

    Boudry, J.C.; Pech, R.

    1991-01-01

    Radioactive waste conditioning is a major step in the processes implemented in nuclear installations. The objective is to contain the radioactive materials in nuclear waste as satisfactory as possible for man and the environment contained ensuring containment integrity having to be guaranteed over very long periods of time. Medium-level (ML) and even very low-level (LL) waste is no exception to this rule. Cogema thus conducted research for many years and developed a novel process to condition nuclear waste in containers reinforced with metal fibres, called fibre concrete containers. This process, welcomed by the French Safety Authorities and ANDRA, the French Radioactive Waste Management Agency, currently appears to be the best way to condition low and medium-level solid waste. (author)

  19. Constructive applications of composite gypsum reinforced with Typha Latifolia fibres

    Directory of Open Access Journals (Sweden)

    Garcia Santos, A.

    2004-03-01

    Full Text Available The present research analyses the possibility to reinforce gypsum using enea fibres (Typha Latifolia creating a compound material in wich the fibres contribute to increase mechanical resistance, producing as well a reduction of the weight and a possible regulation of the set time.

    La investigación presente analiza la posibilidad de reforzar los morteros de escayola mediante la utilización dé fibras de Typha Latifolia, creando un material compuesto en el que las fibras contribuyen al aumento de resistencia mecánica, a la vez que se produce una reducción del peso y una regulación de los tiempos de fraguado. Las propiedades de estos materiales hacen que, en determinadas aplicaciones, su utilización resulte ventajosa con respecto a materiales tradicionales.

  20. Steel Fibre Reinforced Concrete Simulation with the SPH Method

    Science.gov (United States)

    Hušek, Martin; Kala, Jiří; Král, Petr; Hokeš, Filip

    2017-10-01

    Steel fibre reinforced concrete (SFRC) is very popular in many branches of civil engineering. Thanks to its increased ductility, it is able to resist various types of loading. When designing a structure, the mechanical behaviour of SFRC can be described by currently available material models (with equivalent material for example) and therefore no problems arise with numerical simulations. But in many scenarios, e.g. high speed loading, it would be a mistake to use such an equivalent material. Physical modelling of the steel fibres used in concrete is usually problematic, though. It is necessary to consider the fact that mesh-based methods are very unsuitable for high-speed simulations with regard to the issues that occur due to the effect of excessive mesh deformation. So-called meshfree methods are much more suitable for this purpose. The Smoothed Particle Hydrodynamics (SPH) method is currently the best choice, thanks to its advantages. However, a numerical defect known as tensile instability may appear when the SPH method is used. It causes the development of numerical (false) cracks, making simulations of ductile types of failure significantly more difficult to perform. The contribution therefore deals with the description of a procedure for avoiding this defect and successfully simulating the behaviour of SFRC with the SPH method. The essence of the problem lies in the choice of coordinates and the description of the integration domain derived from them – spatial (Eulerian kernel) or material coordinates (Lagrangian kernel). The contribution describes the behaviour of both formulations. Conclusions are drawn from the fundamental tasks, and the contribution additionally demonstrates the functionality of SFRC simulations. The random generation of steel fibres and their inclusion in simulations are also discussed. The functionality of the method is supported by the results of pressure test simulations which compare various levels of fibre reinforcement of SFRC

  1. Preparation and Property Study of Graphene Oxide Reinforced Epoxy Resin Insulation Nanocomposites with High Heat Conductivity

    Science.gov (United States)

    Shan, Xinran; Liu, Yongchang; Wu, Zhixiong; Liu, Huiming; Zhang, Zhong; Huang, Rongjin; Huang, Chuanjun; Liu, Zheng; Li, Laifeng

    2017-02-01

    In this paper, graphene oxide reinforced epoxy resin nanocomposites were successfully prepared. Compared with unmodified epoxy resin, the heat conductivity of the graphene oxide reinforced epoxy resin nanocomposites had been improved while keeping the insulation performance. The tensile strength was investigated at both room temperature (300 K) and liquid nitrogen temperature (77 K). And the fracture surfaces were examined by scanning electron microscopy (SEM). Results showed that the materials had excellent mechanical properties, which could be advantages for the applications as insulating layer in low temperature superconducting magnets.

  2. Observations on the electrical resistivity of steel fibre reinforced concrete

    DEFF Research Database (Denmark)

    Solgaard, Anders Ole Stubbe; Geiker, Mette Rica; Edvardsen, Carola

    2014-01-01

    Steel fibre reinforced concrete (SFRC) is in many ways a well-known construction material, and its use has gradually increased over the last decades. The mechanical properties of SFRC are well described based on the theories of fracture mechanics. However, knowledge on other material properties...... fraction and the moisture content of the SFRC on its electrical resistivity. The electrical resistivity was measured by alternating current (AC) at 126 Hz. Moreover, an analytical model for the prediction of the electrical resistivity of SFRC is presented. The analytical model is capable of predicting...

  3. Surface waves in fibre-reinforced anisotropic elastic media

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    The absence of stress over the free surface enables us to replace the right-hand side of (20) and (21) by zero, giving. 2rA + (s2 − 1)B = 0,. (24). [(λ + α) + r2(λ + 2µT )A − (2µT − α)s = 0. (25). Eliminating A and B from (24) and (25) we obtain the Rayleigh type of waves in the fibre-reinforced elastic medium as. (1 − s2)[(λ + α) + ...

  4. The fracture of boron fibre-reinforced 6061 aluminium alloy

    Science.gov (United States)

    Wright, M. A.; Welch, D.; Jollay, J.

    1979-01-01

    The fracture of 6061 aluminium alloy reinforced with unidirectional and cross-plied 0/90 deg, 0/90/+ or - 45 deg boron fibres has been investigated. The results have been described in terms of a critical stress intensity, K(Q). Critical stress intensity factors were obtained by substituting the failure stress and the initial crack length into the appropriate expression for K(Q). Values were obtained that depended on the dimensions of the specimens. It was therefore concluded that, for the size of specimen tested, the values of K(Q) did not reflect any basic materials property.

  5. Study of injection moulded long glass fibre-reinforced polypropylene and the effect on the fibre length and orientation distribution

    Science.gov (United States)

    Parveeen, B.; Caton-Rose, P.; Costa, F.; Jin, X.; Hine, P.

    2014-05-01

    Long glass fibre (LGF) composites are extensively used in manufacturing to produce components with enhanced mechanical properties. Long fibres with length 12 to 25mm are added to a thermoplastic matrix. However severe fibre breakage can occur in the injection moulding process resulting in shorter fibre length distribution (FLD). The majority of this breakage occurs due to the melt experiencing extreme shear stress during the preparation and injection stage. Care should be taken to ensure that the longer fibres make it through the injection moulding process without their length being significantly degraded. This study is based on commercial 12 mm long glass-fibre reinforced polypropylene (PP) and short glass fibre Nylon. Due to the semi-flexiable behaviour of long glass fibres, the fibre orientation distribution (FOD) will differ from the orientation distribution of short glass fibre in an injection molded part. In order to investigate the effect the change in fibre length has on the fibre orientation distribution or vice versa, FOD data was measured using the 2D section image analyser. The overall purpose of the research is to show how the orientation distribution chnages in an injection moulded centre gated disc and end gated plaque geometry and to compare this data against fibre orientation predictions obtained from Autodesk Moldflow Simulation Insight.

  6. Comparison of traditional field retting and Phlebia radiata Cel 26 retting of hemp fibres for fibre-reinforced composites

    DEFF Research Database (Denmark)

    Liu, Ming; Ale, Marcel Tutor; Kołaczkowski, Bartłomiej

    2017-01-01

    Classical field retting and controlled fungal retting of hemp using Phlebia radiata Cel 26 (a mutant with low cellulose degrading ability) were compared with pure pectinase treatment with regard to mechanical properties of the produced fibre/epoxy composites. For field retting a classification...

  7. The effects of steel fibre reinforced concrete on system ductility

    Directory of Open Access Journals (Sweden)

    Yilmaz, U. S.

    2007-03-01

    Full Text Available Steel fibre-reinforced concrete is being used extensively today in both field applications and experimental studies on concrete strength and ductility. The state of passive confinement generated by the fibre delays cracking and enhances ductility. The present paper reports on both experimental and analytical studies. In the former, a series of 16 steel-fibre reinforced concrete prismatic specimens were subjected to axial loads and the respective axial load-unit strain diagrams were subsequently plotted to determine the effect of steel fibres on reinforced concrete column ductility. Secondly, an analytical study was run to determine the additional ductility accruing to a frame system when steel fibres are included in the concrete. Analytical models were generated for 16 two-storey, single-span reinforced concrete frames. The columns in these frames were designed to the same characteristics as the specimens used in the experimental tests. Non-linear static (pushover analyses were performed for each frame to obtain load-displacement curves and determine the effect of steel fibres on reinforced concrete column ductility.El hormigón reforzado con fibra de acero se emplea actualmente tanto en obra como en los trabajos experimentales para estudiar la resistencia mecánica y ductilidad del hormigón. El estado de confinamiento pasivo producido por la fibra retrasa la fisuración y aumenta la ductilidad. El presente trabajo es de índole tanto experimental como analítica. En primer lugar, en la parte experimental se aplica una fuerza axial a 16 probetas prismáticas (160 x 160 x 840 mm de hormigón reforzado con fibra de acero para determinar su comportamiento, obteniéndose las curvas de fuerza axial-deformación unitaria correspondientes a partir de los resultados observados. A partir de una evaluación de dichos resultados experimentales, se determina el efecto que ejercen las fibras de acero sobre la ductilidad de las probetas de hormigón armado

  8. Modelling of volumetric composition and mechanical properties of unidirectional hemp/epoxy composites - Effect of enzymatic fibre treatment

    Science.gov (United States)

    Liu, M.; Thygesen, A.; Meyer, AS; Madsen, B.

    2016-07-01

    The objective of the present study is to assess the effect of enzymatic fibre treatments on the fibre performance in unidirectional hemp/epoxy composites by modelling the volumetric composition and mechanical properties of the composites. It is shown that the applied models can well predict the changes in volumetric composition and mechanical properties of the composites when differently treated hemp fibres are used. The decrease in the fibre correlated porosity factor with the enzymatic fibre treatments shows that the removal of pectin by pectinolytic enzymes results in a better fibre impregnation by the epoxy matrix, and the mechanical properties of the composites are thereby increased. The effective fibre stiffness and strength established from the modelling show that the enzymatic removal of pectin also leads to increased mechanical properties of the fibres. Among the investigated samples, the composites with hydrothermally pre-treated and enzymatically treated fibres have the lowest porosity factor of 0.08 and the highest mechanical properties. In these composites, the effective fibre stiffness and strength are determined to be 83 GPa and 667 MPa, respectively, when the porosity efficiency exponent is set equal to 2. Altogether, it is demonstrated that the applied models provide a concept to be used for the evaluation of performance of treated fibres in composites.

  9. Drying Shrinkage Behaviour of Fibre Reinforced Concrete Incorporating Polyvinyl Alcohol Fibres and Fly Ash

    Directory of Open Access Journals (Sweden)

    Amin Noushini

    2014-01-01

    Full Text Available The current study assesses the drying shrinkage behaviour of polyvinyl alcohol fibre reinforced concrete (PVA-FRC containing short-length (6 mm and long-length (12 mm uncoated monofilament PVA fibres at 0.125%, 0.25%, 0.375%, and 0.5% volumetric fractions. Fly ash is also used as a partial replacement of Portland cement in all mixes. PVA-FRC mixes have been compared to length change of control concrete (devoid of fibres at 3 storage intervals: early-age (0–7 days, short-term (0–28 days, and long-term (28–112 days intervals. The shrinkage results of FRC and control concrete up to 112 days indicated that all PVA-FRC mixes exhibited higher drying shrinkage than control. The shrinkage exhibited by PVA-FRC mixes ranged from 449 to 480 microstrain, where this value was only 427 microstrain in the case of control. In addition, the longer fibres exhibited higher mass loss, thus potentially contributing to higher shrinkage.

  10. The effect of fibre content, fibre size and alkali treatment to Charpy impact resistance of Oil Palm fibre reinforced composite material

    Science.gov (United States)

    Fitri, Muhamad; Mahzan, Shahruddin

    2016-11-01

    In this research, the effect of fibre content, fibre size and alkali treatment to the impact resistance of the composite material have been investigated, The composite material employs oil palm fibre as the reinforcement material whereas the matrix used for the composite materials are polypropylene. The Oil Palm fibres are prepared for two conditions: alkali treated fibres and untreated fibres. The fibre sizes are varied in three sizes: 5mm, 7mm and 10mm. During the composite material preparation, the fibre contents also have been varied into 3 different percentages: 5%, 7% and 10%. The statistical approach is used to optimise the variation of specimen determined by using Taguchi method. The results were analyzed also by the Taguchi method and shows that the Oil Palm fibre content is significantly affect the impact resistance of the polymer matrix composite. However, the fibre size is moderately affecting the impact resistance, whereas the fibre treatment is insignificant to the impact resistance of the oil palm fibre reinforced polymer matrix composite.

  11. Glass fibres reinforced polyester composites degradation monitoring by surface analysis

    Energy Technology Data Exchange (ETDEWEB)

    Croitoru, Catalin [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania); Patachia, Silvia, E-mail: st.patachia@unitbv.ro [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Papancea, Adina [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Baltes, Liana; Tierean, Mircea [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania)

    2015-12-15

    Highlights: • Glass fibre-reinforced polyester composites surface analysis by photographic method. • The composites are submitted to accelerated ageing by UV irradiation at 254 nm. • The UV irradiation promotes differences in the surface chemistry of the composites. • MB dye is differently adsorbed on surfaces with different degradation degrees. • Good correlation between the colouring degree and surface chemistry. - Abstract: The paper presents a novel method for quantification of the modifications that occur on the surface of different types of gel-coated glass fibre-reinforced polyester composites under artificial UV-ageing at 254 nm. The method implies the adsorption of an ionic dye, namely methylene blue, on the UV-aged composite, and computing the CIELab colour space parameters from the photographic image of the coloured composite's surface. The method significantly enhances the colour differences between the irradiated composites and the reference, in contrast with the non-coloured ones. The colour modifications that occur represent a good indicative of the surface degradation, alteration of surface hydrophily and roughness of the composite and are in good correlation with the ATR-FTIR spectroscopy and optical microscopy results. The proposed method is easier, faster and cheaper than the traditional ones.

  12. THE USE OF SISAL FIBRE AS REINFORCEMENT IN CEMENT BASED COMPOSITES

    Directory of Open Access Journals (Sweden)

    Romildo Dias Tolêdo Filho

    1999-08-01

    Full Text Available ABSTRACT The inclusion of fibre reinforcement in concrete, mortar and cement paste can enhance many of the engineering properties of the basic materials, such as fracture toughness, flexural strength and resistance to fatigue, impact, thermal shock and spalling. In recent years, a great deal of interest has been created worldwide on the potential applications of natural fibre reinforced, cement based composites. Investigations have been carried out in many countries on various mechanical properties, physical performance and durability of cement based matrices reinforced with naturally occurring fibres including sisal, coconut, jute, bamboo and wood fibres. These fibres have always been considered promising as reinforcement of cement based matrices because of their availability, low cost and low consumption of energy. In this review, the general properties of the composites are described in relation to fibre content, length, strength and stiffness. A chronological development of sisal fibre reinforced, cement based matrices is reported and experimental data are provided to illustrate the performance of sisal fibre reinforced cement composites. A brief description on the use of these composite materials as building products has been included. The influence of sisal fibres on the development of plastic shrinkage in the pre-hardened state, on tensile, compressive and bending strength in the hardened state of mortar mixes is discussed. Creep and drying shrinkage of the composites and the durability of natural fibres in cement based matrices are of particular interest and are also highlighted. The results show that the composites reinforced with sisal fibres are reliable materials to be used in practice for the production of structural elements to be used in rural and civil construction. This material could be a substitute asbestos-cement composite, which is a serious hazard to human and animal health and is prohibited in industrialized countries. The

  13. Mechanical Reinforcement of Epoxy Composites with Carbon Fibers and HDPE

    Science.gov (United States)

    He, R.; Chang, Q.; Huang, X.; Li, J.

    2018-01-01

    Silanized carbon fibers (CFs) and a high-density polyethylene with amino terminal groups (HDPE) were introduced into epoxy resins to fabricate high-performance composites. A. mechanical characterization of the composites was performed to investigate the effect of CFs in cured epoxy/HDPE systems. The composites revealed a noticeable improvement in the tensile strength, elongation at break, flexural strength, and impact strength in comparison with those of neat epoxy and cured epoxy/HDPE systems. SEM micrographs showed that the toughening effect could be explained by yield deformations, phase separation, and microcracking.

  14. Reuse of polyethylene fibres from discarded fishing nets as reinforcement in gypsym-based materials

    DEFF Research Database (Denmark)

    Bertelsen, Ida Maria Gieysztor; Ottosen, Lisbeth M.

    In this study, the potential of reusing plastic fibres from discarded waste fishing nets of polyethylene (PE) as fibre reinforcement in gypsum-based building materials is investigated. The fishing nets were not reprocessed, but simply washed and cut to monofilament fibres by an industrial operation...

  15. How to predict the orientation factor of non-rigid macro-synthetic fibre reinforced concrete

    Science.gov (United States)

    Alberti, M. G.; Enfedaque, A.; Gálvez, J. C.

    2017-09-01

    Polyolefin fibre reinforced concrete can met the requirements set in the standards that enable to consider the residual strengths in structural design. Such residual load-bearing capacity of fibre reinforced concrete is assessed by flexural tensile tests in which the presence of fibres can bridge the crack formed and provide strengths that are directly related with the number of fibres and their positioning in the fracture surface. Therefore, the orientation and distribution of the fibres is decisive in the mechanical behaviour of fibre-reinforced concrete and this can be estimated by means of the orientation factor. Several classical models have been extensively used for the case of rigid steel fibres. The increasing interest in structural synthetic fibres that can bend demands new considerations in this matter. A probabilistic model that considers the previous research with stereographical assumptions has been performed allowing the use of fibres that can bend. This study has developed significant tools for design with the aim of predicting such number of fibres crossing a vertical surface using fibre reinforced concrete with steel and polyolefin fibres. The model has been verified with experimental data and represents with accuracy the existence of boundaries, the type of concrete and compaction methods used to cast the moulds.

  16. Fibre Length Reduction in Natural Fibre-Reinforced Polymers during Compounding and Injection Moulding—Experiments Versus Numerical Prediction of Fibre Breakage

    Directory of Open Access Journals (Sweden)

    Katharina Albrecht

    2018-03-01

    Full Text Available To establish injection-moulded, natural fibre-reinforced polymers in the automotive industry, numerical simulations are important. To include the breakage behaviour of natural fibres in simulations, a profound understanding is necessary. In this study, the length and width reduction of flax and sisal fibre bundles were analysed experimentally during compounding and injection moulding. Further an optical analysis of the fibre breakage behaviour was performed via scanning electron microscopy and during fibre tensile testing with an ultra-high-speed camera. The fibre breakage of flax and sisal during injection moulding was modelled using a micromechanical model. The experimental and simulative results consistently show that during injection moulding the fibre length is not reduced further; the fibre length was already significantly reduced during compounding. For the mechanical properties of a fibre-reinforced composite it is important to overachieve the critical fibre length in the injection moulded component. The micromechanical model could be used to predict the necessary fibre length in the granules.

  17. Mechanical properties of ramie fiber reinforced epoxy lamina composite for socket prosthesis

    Directory of Open Access Journals (Sweden)

    Tresna Soemardi

    2010-10-01

    Full Text Available This paper presents an investigation into the application of natural fiber composite especially ramie fiber reinforced epoxy lamina composite for socket prosthesis. The research focuses on the tensile and shear strength from ramie fiber reinforced epoxy lamina composite which will be applied as alternative material for socket prosthesis. The research based on American Society for Testing Material (ASTM standard D 3039/D 3039M for tensile strength and ASTM D 4255/D 4255M-83 for shear strength. The ramie fiber applied is a fiber continue 100 % Ne14'S with Epoxy Resin Bakelite EPR 174 as matrix and Epoxy Hardener V-140 as hardener. The sample composite test made by hand lay up method. Multiaxial characteristic from ramie fiber reinforced epoxy composite will be compared with ISO standard for plastic/polymer for health application and refers strength of material application at Prosthetics and Orthotics. The analysis was completed with the mode of the failure and the failure criterion observation by using Scanning Electron Microscope (SEM. Based on results of the research could be concluded that ramie fiber reinforced epoxy composite could be developed further as the alternative material for socket prosthesis on Vf 40-50%. Results of the research will be discussed in more detail in this paper.

  18. Fibre Bragg Grating Sensor Signal Post-processing Algorithm: Crack Growth Monitoring in Fibre Reinforced Plastic Structures

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2016-01-01

    that enables crack detection was developed. Double Cantilever Beams specimens made with glass fibre and bonded with structural adhesive, were instrumented with a Fibre Bragg Grating array embedded in the host material, and tested using an experimental fracture procedure. This method was successfully validated......A novel method to assess a crack growing/damage event in fibre reinforced plastic, using conventional single mode Fibre Bragg Grating sensors embedded in the host material is presented in this article. Three different damage mechanisms that can change the sensor output, longitudinal strain εxx...... in three different loading conditions, where were obtained very promising results that enable crack growth monitoring....

  19. Tensile Properties of Unsaturated Polyester and Epoxy Resin Reinforced with Recycled Carbon-Fiber-Reinforced Plastic

    Science.gov (United States)

    Okayasu, Mitsuhiro; Kondo, Yuta

    2017-08-01

    To better understand the mechanical properties of recycled carbon-fiber-reinforced plastic (rCFRP), CFRP crushed into small pieces was mixed randomly in different proportions (0-30 wt%) with two different resins: unsaturated polyester and epoxy resin. Two different sizes of crushed CFRP were used: 0.1 mm × 0.007 mm (milled CFRP) and 30 mm × 2 mm (chopped CFRP). The tensile strength of rCFRP was found to depend on both the proportion and the size of the CFRP pieces. It increased with increasing proportion of chopped CFRP, but decreased with increasing proportion of milled CFRP. There was no clear dependence of the tensile strength on the resin that was used. A low fracture strain was found for rCFRP samples made with chopped CFRP, in contrast to those made with milled CFRP. The fracture strain was found to increase with increasing content of milled CFRP up to 20 wt%, at which point, coalescence of existing microvoids occurred. However, there was a reduction in fracture strain for rCFRP with 30 wt% of milled CFRP, owing to the formation of defects (blow holes). Overall, the fracture strain was higher for rCFRPs based on epoxy resin than for those based on unsaturated polyester with the same CFRP content, because of the high ductility of the epoxy resin. The different tensile properties reflected different failure characteristics, with the use of chopped CFRP leading to a complicated rough fracture surface and with milled CFRP causing ductile failure through the presence of tiny dimple-like fractures. However, for a high content of milled CFRP (30 wt%), large blow holes were observed, leading to low ductility.

  20. Analysis of filler--fibre interaction in fly ash filled short fibre-epoxy ...

    Indian Academy of Sciences (India)

    Size and aspect ratio are believed to influence the rheology or the flow in the mixture and in turn the mechanical performance of the composites. Fillers and fibres when used in combination are expected to complement each other's performance resulting in better properties for the composite. They also reduce the extent of ...

  1. A Particle Element Approach for Modelling the 3D Printing Process of Fibre Reinforced Polymer Composites

    OpenAIRE

    Yang, D; Wu, K; Wan, L; Sheng, Y

    2017-01-01

    This paper presents a new numerical approach for modelling the 3D printing process of fibre reinforced polymer composites by fused deposition modelling (FDM). The approach is based on the coupling between two particle methods, namely smoothed particle hydrodynamics (SPH) and discrete element method (DEM). The coupled SPH-DEM model has distinctive advantages in dealing with the free surface flow, large deformation of fibres, and/or fibre-fibre interaction that are involved in the FDM process. ...

  2. A Micro Raman Investigation of Viscoelasticity in Short Fibre Reinforced Polymer Matrix Composites

    DEFF Research Database (Denmark)

    Schjødt-Thomsen, Jan

    The purpose of the present Ph.D. project is to investigate the load transfer mechanisms between the fibre and matrix and the stress/strain fields in and around single fibres in short fibre reinforced viscoelastic polymer matrix composites subjected to various loading histories. The materials...... considered are high modulus carbon fibres embedded in a polypropylene matrix. The polypropylene matrix displays nonlinear viscoelasticity and its constitutive behaviour is modelled using the Schapery model....

  3. Development of sugar palm yarn/glass fibre reinforced unsaturated polyester hybrid composites

    Science.gov (United States)

    Nurazzi, N. Mohd; Khalina, A.; Sapuan, S. Mohd; Rahmah, M.

    2018-04-01

    This study investigates the effect of fibre hybridization for sugar palm yarn fibre with glass fibre reinforced with unsaturated polyester composites. In this work, unsaturated polyester resin are reinforced with fibre at a ratio of 70:30 wt% and 60:40 wt%. The hybrid composites were characterized in terms of physical (density and water absorption), mechanical (tensile, flexural and compression) and thermal properties through thermal gravimetry analysis (TGA). Density determination showed that density increased with higher wt% of glass fibre. The inherently higher density of glass fibre increased the density of hybrid composite. Resistance to water absorption is improved upon the incorporation of glass fibre and the hybrid composites were found to reach equilibrium absorption at days 4 and 5. As for mechanical performance, the highest tensile strength, tensile modulus, flexural strength, flexural modulus and compression strength were obtained from 40 wt% of fibres reinforcement with ratio of 50:50 wt% of sugar palm yarn fibre and glass fibre reinforced unsaturated polyester composites. The increase of glass fibre loading had a synergistic effect on the mechanical properties to the composites structure due to its superior strength and modulus. The thermal stability of hybrid composites was improved by the increase of onset temperature and the reduction of residues upon increase in temperature.

  4. Enhanced Flexural Strength of Tellurium Nanowires/epoxy Composites with the Reinforcement Effect of Nanowires

    Science.gov (United States)

    Balguri, Praveen Kumar; Harris Samuel, D. G.; Aditya, D. B.; Vijaya Bhaskar, S.; Thumu, Udayabhaskararao

    2018-02-01

    Investigating the mechanical properties of polymer nanocomposite materials has been greatly increased in the last decade. In particular, flexural strength plays a major role in resisting bending and shear loads of a composite material. Here, one dimensional (1D) tellurium nanowires (TeNWs) reinforced epoxy composites have been prepared and the flexural properties of resulted TeNWs/epoxy nanocomposites are studied. The diameter and length of the TeNWs used to make TeNWs/epoxy nanocomposites are 21±2.5 nm and 697±87 nm, respectively. Plain and TeNWs/epoxy nanocomposites are characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). Furthermore, significant enhancement in the flexural strength of TeNWs/epoxy nanocomposite is observed in comparison to plain epoxy composite, i.e. flexural strength is increased by 65% with the addition of very little amount of TeNWs content (0.05 wt.%) to epoxy polymer. Structural details of plain and TeNWs/epoxy at micrometer scale were examined by scanning electron microscopy (SEM). We believe that our results provide a new type of semiconductor nanowires based high strength epoxy polymer nanocomposites.

  5. CARBON-FIBRE-REINFORCED POLYMER PARTS EFFECT ON SPACECRAFT OPTOELECTRONIC MODULE LENS SCATTERING

    Directory of Open Access Journals (Sweden)

    S. S. Kolasha

    2016-01-01

    Full Text Available Spacecraft optoelectronic modules traditionally have aluminum alloy or titanium alloy casing which substantial weight increases fuel consumption required to put them into orbit and, consequently, total cost of the project. Carbon fiber reinforced polymer based composite constructive materials is an efficient solution that allows reducing weight and dimensions of large optoelectronic modules 1,5–3 times and the coefficient of linear thermal expansion 15–20 times if compared with metals. Optical characteristic is a crucial feature of carbon-fibre-reinforced polymer that determines composite material interaction with electromagnetic emission within the optical range. This work was intended to develop a method to evaluate Carbon fiber reinforced polymer optoelectronic modules casing effect on lens scattering by computer simulation with Zemax application software package. Degrees of scattered, reflected and absorbed radiant flux effect on imaging quality are described here. The work included experimental study in order to determine bidirectional reflectance distribution function by goniometric method for LUP-0.1 carbon fabric check test pieces of EDT-69U epoxy binder with EPOFLEX-0.4 glue layer and 5056-3.5-23-A aluminium honeycomb filler. The scattered emission was registered within a hemisphere above the check test piece surface. Optical detection direction was determined with zenith (0º < θ < 90º and azimuth (0º < φ < 180º angles with 10° increment. The check test piece surface was proved to scatter emission within a narrow angle range (approximately 20° with clear directivity. Carbon fiber reinforced polymers was found to feature integrated reflectance coefficient 3 to 4 times greater than special coatings do. 

  6. UV curing silicon-containing epoxy resin and its glass cloth reinforced composites

    International Nuclear Information System (INIS)

    Yang Guang; Tang Zhuo; Huang Pengcheng

    2007-01-01

    A UV-curable cationic silicon-containing epoxy resin formulation was developed. The gel conversion of the cured resin after 10-min UV irradiation reached 80% in the presence of 5% diaryliodonium salt photoinitiator and 5.5% polyol chain transfer agent by cationic ring-opening polymerization. The glass cloth-reinforced composites were fabricated with the silicon-containing epoxy resin using the wet lay-up technique and UV irradiation. The mechanical properties of the composites were evaluated. Compared with glass cloth reinforced bisphenol A epoxy resin matrix composites, the silicon-containing epoxy resin matrix composites possessed higher tensile strength and interlayer shear strength which was 158.5MPa and 9.9MPa respectively while other mechanical properties such as flexural property and tensile modulus were similar. (authors)

  7. The effect of fiber treatment on abrasive wear properties of palm fiber reinforced epoxy composite

    Science.gov (United States)

    Razak, Muhammad Firdaus Abdul; Bakar, Mimi Azlina Abu; Kasolang, Salmiah; Ahmad, Mohamad Ali

    2017-12-01

    Oil palm industries generate at least 30 million tons of lignocellulosic biomass annually in the form of oil palm trunks (OPT), empty fruit bunches (EFB), oil palm fronds (OPF) and palm pressed fibres (PPF). The palm fiber is one of the natural fibers used as reinforcement in composite materials in order to decrease environmental issues and promotes utilization of renewable resources. This paper presents a study on the effect of alkaline treatment on wear properties of palm fiber reinforced epoxy resin composite. Abrasive wear testing was deployed to investigate the wear profile of the composite surfaces. Testing was carried out which focused on the effect of alkaline treatment to the palm fiber under different amounts of fiber loading i.e. 1 wt%, 3 wt%, 5 wt% and 7 wt%. The palm fibers were soaked into 6 % of alkaline solution or natrium hydroxide (NaOH) for 12 hours. The fiber was treated in order to remove amorphous materials such as hemicelluloses, lignins and pectins of the fiber. The wear test samples were fabricated using hand lay-up technique and cured at room temperature for 24 hours. Surface roughness of the composite material was also measured using the surface measuring instrument. Dry sliding wear test was performed at room temperature at a constant velocity of 1.4 m/s with a constant load of 10 N by using the Abrasion Test Machine. Result shows that 5 wt% and 7 wt% treated palm fiber loadings have better specific wear rate compared to lower fiber loadings. The finding of this study contributes towards material development and utilization in promoting `waste into wealth' which is in line with national aspiration.

  8. MECHANICAL CHARACTERIZATION AND ANALYSIS OF RANDOMLY DISTRIBUTED SHORT BANANA FIBER REINFORCED EPOXY COMPOSITES

    Directory of Open Access Journals (Sweden)

    R. K. Misra

    2014-03-01

    Full Text Available Short banana fiber reinforced composites have been prepared in laboratory to determine mechanical properties. It has been observed that as soon as the percentage of the banana fiber increases slightly there is a tremendous increase in ultimate tensile strength, % of strain and young modulus of elasticity. Reinforcement of banana fibers in epoxy resin increases stiffness and decreases damping properties of the composites. Therefore, 2.468% banana fiber reinforced composite plate stabilizes early as compared to 7.7135 % banana fiber reinforced composite plate but less stiff as compared to 7.7135 % banana fiber reinforced composite plate

  9. REPAIR AND STRENGTHENING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLIMER (FRP MATERIALS

    Directory of Open Access Journals (Sweden)

    Nihat ÇETİNKAYA

    2004-03-01

    Full Text Available The use of Fibre Reinforced Polimer (FRP materials for the repair and strengthening of Reinforced Concrete structures has become widespread recently. FRP materials are being prefered because they have very high tensile strength, resistance to corrosion and they do not affect the use of the building during the repair and strengthening process. Four reinfoced concrete beams repaired and strengthened with FRP materials have been used in this study which were performed at Pamukkale University-Faculty of Engineering- Civil Engineering Department- Structural Engineering Laboratuary. The behaviour of the beams before and after repair and strengthening was compared by obtaining the load- displacement curves under static loading. In this study, it was observed that the repair and strengthening of reinforced concrete beams by using FRP materials had increased the load carrying capacity significantly.

  10. ENVIRONMENTAL IMPACT OF FIBRE-REINFORCED POLYMER STRENGTHENING SOLUTIONS OF REINFORCED CONCRETE COLUMNS

    Directory of Open Access Journals (Sweden)

    Sebastian George MAXINEASA

    2015-11-01

    Full Text Available The construction sector is considered by many as one of the key factors in fulfilling the three dimensions of sustainability. Notwithstanding its indisputable influence over economy and society at large, the statement above is most importantly justified by the massive impact the construction industry exerts over the environment. Strengthening existing reinforced concrete structures with composites and reusing them instead of building new ones is one of the ways by which the impact of the built environment over the natural one can be successfully decreased. This paper aims at determining if the extension of the life span of the reinforced concrete columns by applying different carbon fibre-reinforced polymer (CFRP strengthening systems can be considered a viable solution in terms of the ecological dimension of sustainability. The results obtained after conducting Life Cycle Assessment (LCA studies encourage the usage of the composite systems hereby analysed in the context of achieving the environmental aspect of sustainability in the construction sector.

  11. Flexural behaviour and punching shear of selfcompacting concrete ribbed slab reinforced with steel fibres

    Directory of Open Access Journals (Sweden)

    Ahmad Hazrina

    2017-01-01

    Full Text Available This paper investigates the effects of steel fibres as a replacement to the conventional reinforcement under flexural behaviour and punching shear in self-compacting (SCC ribbed slab reinforced with steel fibres. Four ribbed slabs with similar dimensions of 2.8 m length × 1.2 m width and 0.2m thickness were constructed. Two of the samples were considered as control samples (conventionally reinforced with reinforcement bars and welded mesh while another two samples were fully reinforced with 1% (80 kg/m3 volume of steel fibres incorporated to the SCC mix. For the flexural behaviour study, the ribbed slab samples were subjected to two line loads under four point bending. Meanwhile, for the punching shear analysis, the ribbed slab samples were subjected to a point load to simulate loading from the column. The analysis of the experimental results displayed that steel fibres incorporation had been found to effectively delay the first crack occurrence under both flexural and punching shear. The steel fibre replacement has been proven to be able to sustain up to 80% and 73% of the ultimate load resistance for flexural and punching shear, respectively, in comparison to conventionally reinforced ribbed slab structure. The visual observation carried out during the experiment exhibited similar failure mode for both steel fibre reinforced and control samples. This was observed for both flexural and punching shear samples. Overall, it can be concluded that the steel fibres had displayed a promising potential to effectively replace the conventional reinforcements.

  12. Carbon fibre-reinforced, alkali-activated slag mortars

    Directory of Open Access Journals (Sweden)

    Garcés, P.

    2007-12-01

    Full Text Available The paper describes the effect of carbon fibre on alkaliactivated slag mortar (AAS mechanical strength, volume stability and reinforcing steel corrosion, compared to its effect on the same properties in Portland cement (PC properties. Mechanical strength and volume stability tests were performed as set out in the respective Spanish UNE standards. The corrosion rate of steel embedded in the specimens studied was determined from polarization resistance analysis. One of the findings of the study performed was that carbon fibre failed to improve AAS or CP mortar strength. As far as volume stability is concerned, the inclusion of carbon fibres in AAS with a liquid/solid ratio of 0.5 reduced drying shrinkage by about 50%. The effect of carbon fibre on PC mortars differed from its effect on AAS mortars. Studies showed that in the presence of carbonation, steel corrosion reached higher levels in carbon-fibre reinforced AAS mortars; the inclusion of 1% carbon fibre improved corrosion resistance perceptibly in these same mortars, however, when exposed to chloride attack.Se ha estudiado el efecto de la incorporación de fibras de carbón en el comportamiento mecánico, estabilidad de volumen y nivel de corrosión de la armadura en morteros de escorias activadas alcalinamente (AAS. Se evalúa la influencia de las fibras de carbón en el comportamiento de morteros alcalinos en comparación con el efecto que producen en morteros de Portland (CP. Los ensayos mecánicos y de estabilidad de volumen se han realizado según lo establecido en la norma UNE que los regula. Se ha utilizado la técnica de la Resistencia a la Polarización para determinar la velocidad de corrosión del acero embebido en las muestras estudiadas. Como consecuencia del estudio realizado, se ha podido concluir que la adición de fibras de carbón a morteros de AAS y CP no mejora las características resistentes de los mismos. En relación con la estabilidad de volumen, la incorporación de

  13. Fiber-Reinforced Epoxy Composites and Methods of Making Same Without the Use of Oven or Autoclave

    Science.gov (United States)

    Barnell, Thomas J. (Inventor); Rauscher, Michael D. (Inventor); Stienecker, Rick D. (Inventor); Nickerson, David M. (Inventor); Tong, Tat H. (Inventor)

    2016-01-01

    Method embodiments for producing a fiber-reinforced epoxy composite comprise providing a mold defining a shape for a composite, applying a fiber reinforcement over the mold, covering the mold and fiber reinforcement thereon in a vacuum enclosure, performing a vacuum on the vacuum enclosure to produce a pressure gradient, insulating at least a portion of the vacuum enclosure with thermal insulation, infusing the fiber reinforcement with a reactive mixture of uncured epoxy resin and curing agent under vacuum conditions, wherein the reactive mixture of uncured epoxy resin and curing agent generates exothermic heat, and producing the fiber-reinforced epoxy composite having a glass transition temperature of at least about 100.degree. C. by curing the fiber reinforcement infused with the reactive mixture of uncured epoxy resin and curing agent by utilizing the exothermically generated heat, wherein the curing is conducted inside the thermally insulated vacuum enclosure without utilization of an external heat source or an external radiation source.

  14. Space charge distributions in glass fibre/epoxy resin composites under dc 10 kV mm-1 electric field

    International Nuclear Information System (INIS)

    Tanaka, Hidesato; Ohki, Yoshimichi; Fukunaga, Kaori; Maeno, Takashi; Okamoto, Kenji

    2007-01-01

    In this paper, the authors discuss one- and three-dimensional space charge distributions in glass fibre/epoxy resin composites. By the conventional pulsed electroacoustic (PEA) method, only a one-dimensional distribution of the average charge over a whole area parallel to the two electrodes can be observed. Therefore, the authors have developed a new PEA system capable of measuring a three-dimensional space charge distribution. Using this system, they measured the charge distribution in glass fibre/epoxy resin composites made of lattice-woven glass fibre and epoxy resin. It has become clear that spatial variation in signal intensity observed depends on the internal structure of the composite. There appear repetitious positions where a high charge density is observed on the same lateral cross section along the vertical direction in the composite. Such positions are consistent with the intersections of the glass fibres. Accumulation of mobile charge carriers or appearance of polarization charge due to mismatch of the ratio of the conductivity and permittivity between the glass fibre and the epoxy resin is thought to be responsible for the PEA signals

  15. THE LHC CRYOMAGNET SUPPORTS IN GLASS-FIBER REINFORCED EPOXY: A LARGE SCALE INDUSTRIAL PRODUCTION WITH HIGH REPRODUCIBILITY IN PERFORMANCE

    International Nuclear Information System (INIS)

    Poncet, A.; Struik, M.; Parma, V.; Trigo, J.

    2008-01-01

    The about 1700 LHC main ring super-conducting magnets are supported within their cryostats on 4700 low heat in leak column-type supports. The supports were designed to ensure a precise and stable positioning of the heavy dipole and quadrupole magnets while keeping thermal conduction heat loads within budget. A trade-off between mechanical and thermal properties, as well as cost considerations, led to the choice of glass fibre reinforced epoxy (GFRE). Resin Transfer Moulding (RTM), featuring a high level of automation and control, was the manufacturing process retained to ensure the reproducibility of the performance of the supports throughout the large production.The Spanish aerospace company EADS-CASA Espacio developed the specific RTM process, and produced the total quantity of supports between 2001 and 2004.This paper describes the development and the production of the supports, and presents the production experience and the achieved performance

  16. The Lhc Cryomagnet Supports in Glass-Fiber Reinforced Epoxy: a Large Scale Industrial Production with High Reproducibility in Performance

    Science.gov (United States)

    Poncet, A.; Struik, M.; Trigo, J.; Parma, V.

    2008-03-01

    The about 1700 LHC main ring super-conducting magnets are supported within their cryostats on 4700 low heat in leak column-type supports. The supports were designed to ensure a precise and stable positioning of the heavy dipole and quadrupole magnets while keeping thermal conduction heat loads within budget. A trade-off between mechanical and thermal properties, as well as cost considerations, led to the choice of glass fibre reinforced epoxy (GFRE). Resin Transfer Moulding (RTM), featuring a high level of automation and control, was the manufacturing process retained to ensure the reproducibility of the performance of the supports throughout the large production. The Spanish aerospace company EADS-CASA Espacio developed the specific RTM process, and produced the total quantity of supports between 2001 and 2004. This paper describes the development and the production of the supports, and presents the production experience and the achieved performance.

  17. The LHC Cryomagnet Supports in Glass-Fiber Reinforced Epoxy A Large Scale Industrial Production with High Reproducibility in Performance

    CERN Document Server

    Poncet, A; Trigo, J; Parma, V

    2008-01-01

    The about 1700 LHC main ring super-conducting magnets are supported within their cryostats on 4700 low heat in leak column-type supports. The supports were designed to ensure a precise and stable positioning of the heavy dipole and quadrupole magnets while keeping thermal conduction heat loads within budget. A trade-off between mechanical and thermal properties, as well as cost considerations, led to the choice of glass fibre reinforced epoxy (GFRE). Resin Transfer Moulding (RTM), featuring a high level of automation and control, was the manufacturing process retained to ensure the reproducibility of the performance of the supports throughout the large production. The Spanish aerospace company EADS-CASA Espacio developed the specific RTM process, and produced the total quantity of supports between 2001 and 2004. This paper describes the development and the production of the supports, and presents the production experience and the achieved performance.

  18. Effect on mechanical properties of glass reinforced epoxy (GRE) pipe filled with different geopolymer filler molarity for piping application

    Science.gov (United States)

    Hashim, M. F. Abu; Abdullah, M. M. A.; Ghazali, C. M. R.; Hussin, K.; Binhussain, M.

    2017-04-01

    This study investigated the use of a novel white clay geopolymer as a filler to produce high strength glass reinforced epoxy pipe. It was found that using white clay geopolymer as filler gives better compressive strength to the glass reinforced epoxy pipe. The disadvantages of current glass reinforced epoxy pipes such low compressive strength which can be replaced by the composite pipes. Geopolymerization is an innovative technology that can transform several aluminosilicate materials into useful products called geopolymers or inorganic polymers. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled with 10 - 40 weight percentages white clay geopolymer filler with 4 Molarity and 8 Molarity were prepared. Morphology of white clay geopolymer filler surface was indicates using scanning electron microscopy. The additions of white clay geopolymer filler for both 4 Molarity and 8 Molarity show higher compressive strength than glass reinforced epoxy pipe without any geopolymer filler. The compressive test of these epoxy geopolymer pipe samples was determined using Instron Universal Testing under compression mode. Nonetheless, the compressive strength of glass reinforced epoxy pipe with white clay geopolymer filler continues to drop when added to 40 wt% of the geopolymer filler loading for both 4 Molarity and 8 Molarity. These outcomes showed that the mixing of geopolymer materials in epoxy system can be attained in this research.

  19. A Review of the Flammability Factors of Kenaf and Allied Fibre Reinforced Polymer Composites

    Directory of Open Access Journals (Sweden)

    C. H. Lee

    2014-01-01

    Full Text Available Natural fibre is a well-known reinforcement fibre in polymer-matrix Composites (PMC lately. Natural fibre has fast growing and abundance properties which make it available at very low cost. For kenaf fibre there is long lists of research projects which have been done regarding its behaviour, and properties and modification made to it. In this paper, fire flammability is the main concern for natural fibre reinforced polymer (NFRP composites especially kenaf fibre. To estimate its flammability, a wide range of factors can be considered such as fibre content, type of matrices, pH conditions, treatment, and fire retardant (FR filler’s type. The most important criteria are the ignition time, rate of propagation, and fire behavior. thermogravimetric analysis (TGA, different scanning calorimetric (DSC, and dynamic mechanical analysis (DMA are the three most famous methods used to investigate the fire behaviour of composites.

  20. Oblique crushing performances of hybrid woven Kenaf fibre reinforced aluminium hollow cylinder

    Directory of Open Access Journals (Sweden)

    Ismail Al Emran

    2017-01-01

    Full Text Available This paper presents crushing performances of hybrid woven kenaf fibre reinforced aluminium tubes under axial and oblique compression. According to open literature, lack number of works conducted to study the crushing responses when kenaf fibre in the form of woven is used to reinforce aluminium tubes. There are important parameters are used such as fibre orientations and oblique compression angles. Kenaf fibre in the form of woven is firstly wetted with polyester resin before it is wrapped around the tubes. After composite hardened, the hybrid tubes are quasi-statically compressed and force-displacement curves are recorded. Energy absorption performances are then determined and discussed in term of different fibre orientations and oblique angles. It is found that [±30°] fibre orientations capable to produce higher force-displacement responses and hybrid tubes are produced lower force ratio indicating the role of natural fibre in increasing the capability of energy absorptions.

  1. Effect of Aging Process in Different Solutions on Kenaf Fibre Structure and Its Interfacial Adhesion in Epoxy Composites

    Directory of Open Access Journals (Sweden)

    A. Shalwan

    2018-01-01

    Full Text Available Interfacial adhesion of kenaf fibres in epoxy composites was investigated using single fibre pull-out test. Several aged kenaf fibres were tested in this work. Two types of kenaf fibres were used in the work, those treated with 6% NaOH and those untreated kenaf fibres. Kenaf fibres were aged in engine oil, water, salt water, and diesel. The pull-out tests were performed using microtensile tests. The tests were performed at 1 mm/min loading rate. Scanning electron microscopy was used to observe the damage on the fibres and the effect of the treatment. The general results revealed that aging of the fibres reduced their strength and interfacial adhesion. Salt water showed the least effect on the strength of the fibres. At most cases, the breakage in the fibres is the main failure. In other words, there is no remarkable effect of aging on the interfacial adhesion since the most impact was on the structure of the fibres.

  2. Structural and electronic properties of carbon nanotube-reinforced epoxy resins.

    Science.gov (United States)

    Suggs, Kelvin; Wang, Xiao-Qian

    2010-03-01

    Nanocomposites of cured epoxy resin reinforced by single-walled carbon nanotubes exhibit a plethora of interesting behaviors at the molecular level. We have employed a combination of force-field-based molecular mechanics and first-principles calculations to study the corresponding binding and charge-transfer behavior. The simulation study of various nanotube species and curing agent configurations provides insight into the optimal structures in lieu of interfacial stability. An analysis of charge distributions of the epoxy functionalized semiconducting and metallic tubes reveals distinct level hybridizations. The implications of these results for understanding dispersion mechanism and future nano reinforced composite developments are discussed.

  3. Blast impact behaviour of concrete with different fibre reinforcement

    Directory of Open Access Journals (Sweden)

    Drdlová Martina

    2015-01-01

    Full Text Available The paper summarizes the results of the development of special concrete intended for the explosion resistance applications, with the emphasis on minimal secondary fragments formation at the explosion. The fine-grained concrete matrix has been reinforced by various types of short dispersed fibers (metallic, mineral and polymer of different sizes and by their combination and the effect of the fibre reinforcement on the physico-mechanical properties and blast resistance was observed. The concrete prism specimens have been subjected to the determination of mechanical parameters (compressive and flexural strength at quasi-static load. The blast tests were conducted on the slab specimens prepared from selected mixtures. The material characteristics and explosion test data have been used for numerical investigation, which defined the optimal wall composition and dimensions of the concrete element which should resist the explosion defined by type, size, weight and placement of the blast. In the next step the test elements resistance was verified by real explosion test.

  4. Assessment of fibre orientation in reinforced concrete using Fourier image transform.

    Science.gov (United States)

    Redon; Chermant; Chermant; Coster

    1998-09-01

    In this study, ribbon-shaped amorphous cast-iron fibres were used to reinforce a concrete matrix. X-ray photographs have been taken to detect fibres in situ. Their orientation has been investigated by automatic image analysis methods. However, this measurement should not be influenced by the digitization on the square frame of the analyser. For that purpose, the Fourier transform was used rather than the rose of direction method. This analysis revealed the transverse isotropic nature of the spatial arrangement of these fibres, whose axis of revolution corresponds to the concrete casting axis. Such a morphological characterization of the fibre-reinforced concrete reveals its mechanical behaviour.

  5. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    Wintec

    forcing materials such as glass fibre, carbon fibre etc are their specific ... this is the substitution of inorganic fibres such as glass or aramid fibres by .... friction. The samples were tested with different loads vary- ing from 1–3 kg. For each load the machine was allowed to run for 15 min and the readings were recorded. After.

  6. Fiber-Reinforced Reactive Nano-Epoxy Composites

    Science.gov (United States)

    Zhong, Wei-Hong

    2011-01-01

    An ultra-high-molecular-weight polyethylene/ matrix interface based on the fabrication of a reactive nano-epoxy matrix with lower surface energy has been improved. Enhanced mechanical properties versus pure epoxy on a three-point bend test include: strength (25 percent), modulus (20 percent), and toughness (30 percent). Increased thermal properties include higher Tg (glass transition temperature) and stable CTE (coefficient of thermal expansion). Improved processability for manufacturing composites includes faster wetting rates on macro-fiber surfaces, lower viscosity, better resin infusion rates, and improved rheological properties. Improved interfacial adhesion properties with Spectra fibers by pullout tests include initial debonding force of 35 percent, a maximum pullout force of 25 percent, and energy to debond at 65 percent. Improved mechanical properties of Spectra fiber composites (tensile) aging resistance properties include hygrothermal effects. With this innovation, high-performance composites have been created, including carbon fibers/nano-epoxy, glass fibers/nano-epoxy, aramid fibers/ nano-epoxy, and ultra-high-molecularweight polyethylene fiber (UHMWPE).

  7. Fibre Bragg Gratings in Embedded Microstructured Optical Fibres Allow Distinguishing between Symmetric and Anti-Symmetric Lamb Waves in Carbon Fibre Reinforced Composites.

    Science.gov (United States)

    De Pauw, Ben; Goossens, Sidney; Geernaert, Thomas; Habas, Dimitrios; Thienpont, Hugo; Berghmans, Francis

    2017-08-24

    Conventional contact sensors used for Lamb wave-based ultrasonic inspection, such as piezo-electric transducers, measure omnidirectional strain and do not allow distinguishing between fundamental symmetric and anti-symmetric modes. In this paper, we show that the use of a single fibre Bragg grating created in a dedicated microstructured optical fibre allows one to directly make the distinction between these fundamental Lamb wave modes. This feature stems from the different sensitivities of the microstructured fibre to axial and transverse strain. We fabricated carbon fibre-reinforced polymer panels equipped with embedded microstructured optical fibre sensors and experimentally demonstrated the strain waves associated with the propagating Lamb waves in both the axial and transverse directions of the optical fibre.

  8. Effect of fibre coating and geometry on the tensile properties of hybrid carbon nanotube coated carbon fibre reinforced composite

    International Nuclear Information System (INIS)

    Shazed, M.A.; Suraya, A.R.; Rahmanian, S.; Mohd Salleh, M.A.

    2014-01-01

    Highlights: • Growth of CNT on carbon fibre (CF) was conducted via floating catalyst CVD process. • CNT-coated CF reinforced polypropylene composites were fabricated and characterized. • Theoretical prediction of composite tensile properties was conducted via mathematical approach. • Acceptable validation was found between experimental and estimated tensile properties. - Abstract: Hierarchically structured hybrid composites are ideal engineered materials to carry loads and stresses due to their high in-plane specific mechanical properties. Growing carbon nanotubes (CNTs) on the surface of high performance carbon fibres (CFs) provides a means to tailor the mechanical properties of the fibre–resin interface of a composite. The growth of CNT on CF was conducted via floating catalyst chemical vapor deposition (CVD). The mechanical properties of the resultant fibres, carbon nanotube (CNT) density and alignment morphology were shown to depend on the CNT growth temperature, growth time, carrier gas flow rate, catalyst amount, and atmospheric conditions within the CVD chamber. Carbon nanotube coated carbon fibre reinforced polypropylene (CNT-CF/PP) composites were fabricated and characterized. A combination of Halpin–Tsai equations, Voigt–Reuss model, rule of mixture and Krenchel approach were used in hierarchy to predict the mechanical properties of randomly oriented short fibre reinforced composite. A fractographic analysis was carried out in which the fibre orientation distribution has been analyzed on the composite fracture surfaces with Scanning Electron Microscope (SEM) and image processing software. Finally, the discrepancies between the predicted and experimental values are explained

  9. Manufacturing Flax Fibre-Reinforced Polypropylene Composites by Hot-Pressing

    Science.gov (United States)

    Jolly, Marc; Jayaraman, Krishnan

    The renewable characteristic of natural fibres, such as flax, and the recyclable nature of thermoplastic polymers, such as polypropylene, provide an attractive eco-friendly quality to the resulting composite materials. Common methods for manufacturing natural fibre-reinforced thermoplastic composites, injection moulding and extrusion, tend to degrade the fibres during processing. Development of a simple manufacturing technique for these composites, that minimises fibre degradation, is the main objective of this study. Flax fibres were conditioned, cut into lengths ranging from 1 mm to 30 mm with scissors and a pelletiser, and shaped into randomly oriented mats using a drop feed tower. Polypropylene in sheet form, was added to the fibres to furnish polypropylene/flax/polypropylene sandwiches with a fibre mass fraction of 25%, which were then consolidated by the hot pressing technique. Tensile, flexural and impact properties of these composite sheets were determined as functions of fibre length and processing temperature.

  10. The behavior of Aluminium Carbon/Epoxy fibre metal laminate under quasi-static loading

    Science.gov (United States)

    Romli, N. K.; Rejab, M. R. M.; Bachtiar, D.; Siregar, J.; Rani, M. F.; Harun, W. S. W.; Salleh, Salwani Mohd; Merzuki, M. N. M.

    2017-10-01

    One of major concerns that related to the flight safety is impact of birds. To minimize the risks, there is need to increase the impact resistance of aircraft by developing a new material and has the good structural design of aircraft structures. The hybrid laminates are potential candidate material to be applied for the aircraft structures susceptible to bird strikes. The fibre metal laminate was fabricated by a compression moulding technique. The carbon fibre and aluminium alloy 2024-0 was laminated by using thermoset epoxy. A compression moulding technique was used for the FML fabrication. The aluminium sheet metal has been roughening by a metal sanding method which to improve the bonding between the fibre and metal layer. The main objective of this paper is to determine the failure response of the laminate under five variations of the crosshead displacement in the quasi-static loading. The FML was modelled and analysed by using Explicit solver. Based on the experimental data of the quasi-static test, the result of 1 mm/min was 11.85 kN and higher than 5, 10, 50 and 100 mm/min which because of the aluminium ductility during the impact loading response. The numerical simulations were generally in good agreement with the experimental measurements.

  11. Bending test in epoxy composites reinforced with continuous and aligned PALF fibers

    Directory of Open Access Journals (Sweden)

    Gabriel Oliveira Glória

    2017-10-01

    Full Text Available Sustainable actions aiming to prevent increasing worldwide pollution are motivating the substitution of environmentally friendly materials for conventional synthetic ones. A typical example is the use of natural lignocellulosic fiber (LCF as reinforcement of polymer composites that have traditionally been reinforced with glass fiber. Both scientific research and engineering applications support the use of numerous LCFs composites. The pineapple fiber (PALF, extracted from the leaves of Ananas comosus, is considered a LCF with potential for composite reinforcement. However, specific mechanical properties and microstructural characterization are still necessary for this purpose. Therefore, the objective of this short work is to evaluate the flexural properties, by means of three points, bend tests, of epoxy composites incorporated with up to 30 vol% of PALF. Results reveal that continuous and aligned fibers significantly increase the flexural strength. Scanning electron microscopy disclosed the fracture mechanism responsible for this reinforcement. Keywords: Pineapple fibers, PALF, Flexural properties, Bending test, Epoxy composites, Fracture mechanism

  12. Friction and Wear Behavior of Carbon Fabric-Reinforced Epoxy Composites

    Science.gov (United States)

    Şahin, Y.; De Baets, Patrick

    2017-12-01

    Besides intrinsic material properties, weight/energy savings and wear performance play an important role in the selection of materials for any engineering application. The tribological behavior of carbon fabric-reinforced epoxy composites produced by molding technique was investigated using a reciprocating pin-on-plate configuration. It was shown that the wear rate considerably decreased (by a factor of approx. 8) with the introduction of the reinforcing carbon fabric into the epoxy matrix. It was observed that the wear rate of the tested composites increased with an increase in normal load. Moreover, the coefficient of friction for epoxy/steel and composites/steel tribo-pairs was also determined and decreased with increasing load. By means of scanning electron microscopy of the wear tracks, different wear mechanisms such as matrix wear, matrix fatigue and cracking, matrix debris formation for neat epoxy together with fabric/fiber thinning, fabric breakage and fabric/matrix debonding for the reinforced epoxy could be distinguished.

  13. Effect of Moisture Absorption Behavior on Mechanical Properties of Basalt Fibre Reinforced Polymer Matrix Composites

    Directory of Open Access Journals (Sweden)

    Amuthakkannan Pandian

    2014-01-01

    Full Text Available The study of mechanical properties of fibre reinforced polymeric materials under different environmental conditions is much important. This is because materials with superior ageing resistance can be satisfactorily durable. Moisture effects in fibre reinforced plastic composites have been widely studied. Basalt fibre reinforced unsaturated polyester resin composites were subjected to water immersion tests using both sea and normal water in order to study the effects of water absorption behavior on mechanical properties. Composites specimens containing woven basalt, short basalt, and alkaline and acid treated basalt fibres were prepared. Water absorption tests were conducted by immersing specimens in water at room temperature for different time periods till they reached their saturation state. The tensile, flexural, and impact properties of water immersed specimens were conducted and compared with dry specimens as per the ASTM standard. It is concluded that the water uptake of basalt fibre is considerable loss in the mechanical properties of the composites.

  14. Application of the fluid dynamics model to the field of fibre reinforced self-compacting concrete

    DEFF Research Database (Denmark)

    Svec, Oldrich; Skocek, Jan; Stang, Henrik

    with the fibre reinforced selfcompacting concrete. A computational tomography scanner together with an image analysis were used to obtain a field of fibre orientation tensors. These tensors were compared to the tensors obtained by the simulation. The comparison shows the ability of the model to predict the real......Ability to properly simulate a form filling process with steel fibre reinforced self-compacting concrete is a challenging task. Such simulations may clarify the evolution of fibre orientation and distribution which in turn significantly influences final mechanical properties of the cast body. We...... have developed such a computational model and briefly introduce it in this paper. The main focus of the paper is towards validation of the ability of the model to properly mimic the flow of the fibre reinforced self-compacting concrete. An experiment was conducted where a square slab was filled...

  15. Use of coconut fibre reinforced concrete and coconut-fibre ropes for seismic-resistant construction

    Directory of Open Access Journals (Sweden)

    Ali, Majid

    2016-03-01

    Full Text Available Earthquake-resistant and economical housing is the most desirable need in rural areas of developing countries. These regions often suffer significant loss of life during a seismic event. To enable an efficient and cost-effective solution, a new concept of construction, i.e. a wallette of interlocking blocks with movability at the interface and rope reinforcement, is investigated. The novel interlocking block is made of coconut fibre reinforced concrete (CFRC. The reason for using coconut fibre is their highest toughness amongst natural fibres. This paper describes the in-plane behaviour of the interlocking wallette under earthquake loadings. The wallette response is measured in terms of induced acceleration, block uplift, top maximum relative displacement and rope tension. The applied earthquake loadings cannot produce any damage in the structure, i.e. blocks and/or ropes. The response of the wallette is explained in detail along with correlation of materials aspect with structural behaviour.En las zonas rurales de los países en desarrollo, entre las características principales que deben reunir las viviendas es que sean tanto económicas como sismoresistentes, ya que en estas zonas la pérdida de vidas humanas debido a los terremotos es aun elevada. A fin de hallar una solución que cumple con estos requisitos de manera técnica y económicamente efectiva, se ha investigado un nuevo concepto constructivo: un murete de bloques conjugados con movilidad en el interfaz y reforzado con cuerda. Este novedoso bloque conjugable está realizado en hormigón reforzado con fibra de coco (CFRC, elegida por su alta tenacidad, la mayor de entre las fibras naturales. El artículo describe el comportamiento dentro del plano del murete conjugado frente a las cargas sísmicas. La respuesta de esta estructura se ha medido en función de la aceleración inducida, el levantamiento de los bloques, el desplazamiento relativo máximo y la tensión de las cuerdas

  16. Thermal and dynamic mechanical properties of cellulose nanofibers reinforced epoxy composites.

    Science.gov (United States)

    Saba, N; Safwan, Ahmad; Sanyang, M L; Mohammad, F; Pervaiz, M; Jawaid, M; Alothman, O Y; Sain, M

    2017-09-01

    The current study presents about the effect of cellulose nanofibers (CNFs) filler on the thermal and dynamic mechanical analysis (DMA) of epoxy composites as a function of temperature. In this study hand lay-up method was used to fabricate CNF reinforced Epoxy nanocomposites with CNF loading of 0.5%, 0.75%, and 1% into epoxy resin. The obtained thermal and DMA results illustrates that thermal stability, char content, storage modulus (E'), loss modulus (E") and glass transition temperature (Tg) increases for all CNF/epoxy nanocomposites compared to the pure epoxy. Thermal results revealed that 0.75% offers superior resistance or stability towards heat compared to its counterparts. In addition, 0.75% CNF/epoxy nanocomposites confers highest value of storage modulus as compared to 0.5% and 1% filler loading. Hence, it is concluded that 0.75% CNFs loading is the minimal to enhance both thermal and dynamic mechanical properties of the epoxy composites and can be utilized for advance material applications where thermal stability along with renewability are prime requirements. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Multiscale carbon nanotube-carbon fiber reinforcement for advanced epoxy composites.

    Science.gov (United States)

    Bekyarova, E; Thostenson, E T; Yu, A; Kim, H; Gao, J; Tang, J; Hahn, H T; Chou, T-W; Itkis, M E; Haddon, R C

    2007-03-27

    We report an approach to the development of advanced structural composites based on engineered multiscale carbon nanotube-carbon fiber reinforcement. Electrophoresis was utilized for the selective deposition of multi- and single-walled carbon nanotubes (CNTs) on woven carbon fabric. The CNT-coated carbon fabric panels were subsequently infiltrated with epoxy resin using vacuum-assisted resin transfer molding (VARTM) to fabricate multiscale hybrid composites in which the nanotubes were completely integrated into the fiber bundles and reinforced the matrix-rich regions. The carbon nanotube/carbon fabric/epoxy composites showed approximately 30% enhancement of the interlaminar shear strength as compared to that of carbon fiber/epoxy composites without carbon nanotubes and demonstrate significantly improved out-of-plane electrical conductivity.

  18. Optimisation of mechanical properties of bamboo fibre reinforced-PLA biocomposites

    Science.gov (United States)

    Nurnadia M., J.; Fazita, M. R. Nurul; Abdul Khalil H. P., S.; Mohamad Haafiz M., K.

    2017-12-01

    The majority of the raw materials that have been widely used in industries are petroleum-based. Growing environmental awareness, the depletion of fossil fuels, and climate change are the key drivers to seek more ecologically friendly materials, such as natural fibres to replace synthetic fibres in polymeric composite. Among the natural fibres available, bamboo fibre has relatively high strength. Poly (lactic) acid (PLA), one of the well-known biopolymers, has been used as a matrix in order to produce totally biodegradable biocomposites. In this study, bamboo fibres were compounded with PLA by a twin screw extruder. The bamboo fibre reinforced PLA composites were then manufactured via the compression moulding method. The influences of screw speed and die temperature during extrusion on the mechanical properties, the tensile and flexural of the biocomposites, were studied. The effects of fibre content and fibre length were also investigated. Taguchi experimental design approach was adopted to determine the optimum set of conditions to achieve the "best" mechanical properties of the composites. Tensile and flexural properties were characterised based on the D638-10 and D790-10 standards, respectively. It was observed that the fibre aspect ratio and fibre content significantly affected the mechanical performance of bamboo fibres reinforced PLA composites.

  19. Analysis of Glass-Reinforced Epoxy Material for Radio Frequency Resonator

    Directory of Open Access Journals (Sweden)

    M. R. Zaman

    2014-01-01

    Full Text Available A radio frequency (RF resonator using glass-reinforced epoxy material for C and X band is proposed in this paper. Microstrip line technology for RF over glass-reinforced epoxy material is analyzed. Coupling mechanism over RF material and parasitic coupling performance is explained utilizing even and odd mode impedance with relevant equivalent circuit. Babinet’s principle is deployed to explicate the circular slot ground plane of the proposed resonator. The resonator is designed over four materials from different backgrounds which are glass-reinforced epoxy, polyester, gallium arsenide (GaAs, and rogers RO 4350B. Parametric studies and optimization algorithm are applied over the geometry of the microstrip resonator to achieve dual band response for C and X band. Resonator behaviors for different materials are concluded and compared for the same structure. The final design is fabricated over glass-reinforced epoxy material. The fabricated resonator shows a maximum directivity of 5.65 dBi and 6.62 dBi at 5.84 GHz and 8.16 GHz, respectively. The lowest resonance response is less than −20 dB for C band and −34 dB for X band. The resonator is prototyped using LPKF (S63 drilling machine to study the material behavior.

  20. Performance evaluation of Iowa bridge decks constructed with epoxy-coated reinforcing bars.

    Science.gov (United States)

    2011-08-01

    Epoxy coatings have been used on the embedded reinforcing bars of bridge decks since the mid-1970s to : mitigate deterioration caused by chloride-induced corrosion. The use of chloride-based deicers became : common in the early 1960s and caused corro...

  1. Enhancement of mechanical properties and interfacial adhesion by chemical odification of natural fibre reinforced polypropylene composites

    CSIR Research Space (South Africa)

    Erasmus, E

    2008-11-01

    Full Text Available , to improve their mechanical properties. Various chemical treatments with acrylic acid, 4-pentanoic acid, 2,4-pentadienoic acid and 2-methyl-4-pentanoic acid were investigated. The natural fibre reinforced polypropylene composites were processed by compression...

  2. Surface topography of machined fibre reinforced plastics obtained by stylus instruments and optical profilometers

    DEFF Research Database (Denmark)

    Eriksen, Else; Hansen, Hans Nørgaard

    1998-01-01

    by stylus instruments and by optical profilometers. The measurements were performed on machined surfaces with three distinct different roughness levels. The materials were two thermoplastics, polyoxymethylene and polypropylene, reinforced with short glass fibres. The two stylus instruments gave almost...

  3. Synthesis and Characterization of Short Saccaharum Cilliare Fibre Reinforced Polymer Composites

    OpenAIRE

    Singha, A. S.; Thakur, Vijay Kumar

    2009-01-01

    This paper deals with the synthesis of short Saccaharum Cilliare fibre (SC) reinforced Urea-Formaldehyde (UF) matrix based polymer composites. Present work reveals that mechanical properties such as: tensile strength, compressive strength, flexural strength and wear resistance of the UF matrix increase up to 30% fibre loading(in terms of weight) and then decreases for higher loading when fibers are incorporated into the matrix polymer. Morphological and Thermal studies of the matrix, fibre ...

  4. Numerical Investigation of Thermal and Thermo-mechanical Effective Properties for Short Fibre Reinforced Composite

    Science.gov (United States)

    Ioannou, Ioannis; Hodzic, Alma; Gitman, Inna M.

    2017-10-01

    This study aims to investigate the thermal conductivity and the linear coefficient of thermal expansion for short fibre reinforced composites. The study combines numerical and statistical analyses in order to primarily examine the representative size and the effective properties of the volume element. Effects of various micromechanical parameters, such as fibre's aspect ratio and fibre's orientation, on the minimum representative size are discussed. The numerically acquired effective properties, obtained for the representative size, are presented and compared with analytical models.

  5. Prediction of fire spalling in fibre-reinforced high strength concrete

    Directory of Open Access Journals (Sweden)

    Mugume R.B.

    2013-09-01

    Full Text Available This paper presents results of a study which investigates spalling in small scale specimens of fibre-reinforced high strength concrete exposed to elevated temperatures. A relationship to predict relative maximum pressures was developed, which takes into account parameters such as concrete strength, fibre type and fibre geometry. Also, a blowtorch spalling test method was utilized to investigate spalling in small scale specimens, and a clear relationship between relative maximum pore pressures and spalling was observed.

  6. Development of hemp fibre reinforced polypropylene composite - Journal Article

    CSIR Research Space (South Africa)

    Hargitai, H

    2005-06-01

    Full Text Available Nonwoven mats from hemp and polypropylene fibres in various proportions were produced and hot pressed to make composite material. The effect of fibre content and the anisotropy in nonwoven mat resulting from the carding technology were examined...

  7. Experimental characterization of fibre-reinforced composites improved with nanofibres or nanotubes

    NARCIS (Netherlands)

    Koysin, V.; Warnet, Laurent; Akkerman, Remko

    2010-01-01

    A review is presented on the testing and mechanical properties of continuous fibre reinforced composites modified with nanotubes or nanofibres either dispersed in the resin or grown on the microfibres. The nano-level cross-links are shown to be able to (1) increase the fibre/matrix interfacial

  8. Hardening in Two-Phase Materials. I. Strength Contributions in Fibre-Reinforced Copper-Tungsten

    DEFF Research Database (Denmark)

    Lilholt, Hans

    1977-01-01

    Cyclic tests (Bauschinger tests) were conducted at 77 K and at room temperature on the fibre-reinforced material of single crystal Cu with long W-fibres of diameter 20 mum and volume fractions up to 4%. These tests enabled two important contributions to the total strength of the unrelaxed material...

  9. Towards an integrated simulation of casting and structural performance of flowable fibre-reinforced concrete

    NARCIS (Netherlands)

    Vidal Sarmiento, E.; Hendriks, M.A.N.; Geiker, M. R.; Kanstad, T.

    2016-01-01

    Most recent studies on fibre-reinforced self-compacting concrete agree on the impact of the casting conditions on the fibre orientation and distribution, and its consequence thereof on the structural performance. A substantial number of investigations are continuously contributing to gain experience

  10. Comparison of impact strength of acrylic resin reinforced with kevlar and polyethylene fibres.

    Science.gov (United States)

    Kamath, G; Bhargava, K

    2002-01-01

    The present study was done to evaluate the impact strengths of heat-activated acrylic resins reinforced with Kevlar fibres, polyethylene fibres and unreinforced heat activated acrylic resin. Each of three groups had 25 specimens. Brass rods of uniform length of 40 mm and diameter of 8 mm were used to prepare the moulds. A combination of long fibres (40 mm length) and short fibres (6 mm length) were used. The total amount of fibres incorporated was limited to 2% by weight of the resin matrix. Short and long fibres of equal weight were incorporated. The short fibres were mixed with polymer and monomer and packed into the mould, while, the long axis of the specimen, perpendicular to the applied force. The specimens were then processed. Impact strength testing was done on Hounsfield's impact testing machine. Kevlar fibre reinforced heat activated acrylic resin specimens recorded higher mean impact strength of 0.8464 Joules, while polyethylene fibres reinforced heat activated acrylic resin recorded mean impact strength of 0.7596 joules. The unreinforced heat activated acrylic resin recorded mean impact strength of 0.3440 Joules.

  11. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    During the last few years, natural fibres have received much more attention than ever before from the research community all over the world. These natural fibres offer a number of advantages over traditional synthetic fibres. In the present communication, a study on the synthesis and mechanical properties of new series of ...

  12. Mechanical properties of short-flax-fibre reinforced compounds

    NARCIS (Netherlands)

    Bos, H.L.; Müssig, J.; Oever, van den M.J.A.

    2006-01-01

    The mechanical properties of flax/polypropylene compounds, manufactured both with a batch kneading and an extrusion process were determined and compared with the properties of Natural fibre Mat Thermoplastic (NMT) composites. The fibre length and width distributions of the fibres from the compounds

  13. Study of damping characteristics of fibre reinforced composite aerospace structure

    International Nuclear Information System (INIS)

    Khan, M.Z.; Saleh, S.; Munir, A.

    2006-01-01

    Composite materials are used in a variety of high demanding structural applications. Apart from their other preferable properties, they have high-energy dissipation characteristics, which is important aspect when we repeatedly wiggle the system back and forth. It is important to have thorough understanding of material damping behavior; in general materials damping tends to be complex nonlinear function of vibration amplitude, frequency of loading and material formulation. There are number of mathematical models available in literature to obtain hysteresis curves. One approach for identifying damping characteristics used mechanical hysteresis curves. In present work, a phenomenon was observed during testing of fibre reinforced composite beam of an aerospace structure, that for increase load in structure, the path of Force vs. Displacement curve is different than the path of unloading. A plot is generated which indicate the hysteresis loop representing the steady state dynamic behavior of material. The area enclosed by such curves is proportional to energy dissipation per cycle. However, the specific shape of the curve also has important implications for characterizing the specific functional form of the damping. Therefore, it is important to develop methods for accurately accounting for such effects. The current work explores the damping characteristics both theoretically and experimentally. (author)

  14. Nanosilica reinforced epoxy floor coating composites: preparation and thermophysical characterization

    Directory of Open Access Journals (Sweden)

    Mir Mohammad Alavi Nikje

    2012-01-01

    Full Text Available In this study, flooring grade epoxy/nanoSiO2 nanocomposites were prepared by in-situ polymerization method. Nano silica was treated by coupling agent in order to surface treating and introducing of reactive functional groups to achieving adequate bonding between polar inorganic nano particles and epoxy organic polymer. γ-Aminopropyltriethoxysilane (Amino A-100 was used as an effective and commercially available coupling agent and nano silica treated in acetone media. SEM observations of cured samples revealed that the nano silica was completely dispersed into polymer matrix into nanoscale particles. Thermal and physical properties of prepared samples were investigated and data showed improvements in physical and mechanical properties of the flooring samples in comparison with unfilled resin.

  15. REINFORCING FIBRES AS PART OF TECHNOLOGY OF CONCRETES

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2012-07-01

    It was identified that the basalt fibre consumption rate influences both the strength and the density of products made of cellular concrete. The length of the basalt fibre impacts the strength of products. A nomogram was developed to identify the consumption rate of the basalt fibre driven by the strength of products and the Portland cement consumption rate. The authors also studied the influence of the consumption rate of Portland cement and basalt fibre onto the structural quality ratio of the foamed fibre concrete.

  16. Computational modelling of fibre-reinforced cementitious composites : An analysis of discrete and mesh-independent techniques

    NARCIS (Netherlands)

    Radtke, F.K.F.

    2012-01-01

    Failure patterns and mechanical behaviour of high performance fibre-reinforced cementitious composites depend to a large extent on the distribution of fibres within a specimen. A discrete treatment of fibres enables us to study the influence of various fibre distributions on the mechanical

  17. Fire-retardant Polyester Composites from Recycled Polyethylene Terephthalate (PET) Wastes Reinforced with Coconut Fibre

    International Nuclear Information System (INIS)

    Nurul Munirah Abdullah; Ishak Ahmad

    2013-01-01

    Coconut fibre reinforced composite was prepared by blending unsaturated polyester resin (UPR) from waste PET with 0.3 v % of coconut fibre. The coconut fibres were pre-treated with sodium hydroxide followed by silane prior to inclusion into the UPR. The untreated coconut fibres reinforced composite were used as a control. DriconR as a phosphate type of flame retardant was then added to the composite to reduce the flammability of the composite. The amount of DriconR was varied from 0 to 10 wt % of the overall mass of resin. The burning properties and limiting oxygen index (LOI) of the treated and untreated composites increased with the addition of Dricon. The tensile strength and modulus of both composites were also increased with the addition of DriconR. The treated fibre composite with 5 wt % DriconR showed the highest burning time and LOI with the values of 101.5 s and 34 s, respectively. The optimum tensile strength and modulus for treated fibre composite was at 5 wt % DriconR whereas the untreated fibre composite was at 2.5 wt % loading of DriconR. Thermogravimetry (TGA) analysis indicated that the degradation temperature increased with the addition of DriconR up to 5 wt % into UPR/ coconut fibre composites. Morphological observations indicated better distribution of DriconR for treated fibre composite resulted in enhancement of the tensile properties of the treated fibre composite. (author)

  18. Temperature Distribution in Fibre-glass Composite Impregnated with Epoxy-Cyanate ester Blend

    Directory of Open Access Journals (Sweden)

    Priyanka Brahmbhatt

    2014-01-01

    Full Text Available Cyanate ester and epoxy blends have been identified as an attractive insulating material for fusion grade magnet winding packs. An insulation system comprising of fibre glass composites and cyanate ester and blend has been analyzed during its vacuum pressure impregnation and curing. The transient one dimensional distribution of temperature and extent of cure has been evaluated both analytically and experimentally in this paper. The one dimensional transient (1-D heat transfer characteristics evaluation has been carried out on 60:40 (epoxy : cyanate which has been optimally prescribed blend for fusion grade winding process. The analytical formulation solves the heat transfer differential equations incorporating internal heat generation resulting from the exothermic chemical reaction in both chemical and diffusional kinetic regimes. In support to the analytical formulation, carefully designed experiments have been carried out on such samples. On comparing the results obtained from analytical formulism and those measured during experiments have been found to be matching well. These results have the potential to design the vacuum pressure impregnation of large size fusion relevant winding packs.

  19. Charpy impact tenacity of epoxy matrix composites reinforced with aligned jute fibers

    Directory of Open Access Journals (Sweden)

    Artur Camposo Pereira

    2017-10-01

    Full Text Available Natural fiber reinforced polymer matrix composites are gaining attention as engineering materials for advanced applications, including components of high performance ballistic armors. This requires superior mechanical properties, such as tenacity. Composites reinforced with jute fiber are currently being investigated as possible advanced engineering materials. Therefore, the objective of the present work was to evaluate the impact resistance of epoxy matrix composites reinforced with up to 30 vol% of continuous and aligned jute fibers. This evaluation was performed by measuring the Charpy absorbed impact energy of standard ASTM notched specimens. The results indicated a significant increase in the absorbed impact energy with the volume fraction of jute fibers. The microstructural mechanism related to this performance was revealed by scanning electron microscopy analysis. Keywords: Jute fiber, Epoxy composites, Charpy, Impact test

  20. Static and cyclic performance of cementitious composites reinforced with glass-fibres

    OpenAIRE

    Arabi, N.

    2018-01-01

    This paper concerns an experimental study of the influence of short glass-fibres randomly oriented of a reinforced cement-based composite on the mechanical behaviour. The matrix material parameters used are: cement/sand ratio and water/cement ratio fixed at 0.5; the glass-fibre content (0%, 0.5%, 1.0%, 1.5%, 2% and 2.5%) and fibre lengths (3, 6 and 12 mm). Composites mechanical characterisation under static behaviour at flexural and compression tests, shows that the reinforcement effect is be...

  1. Challenges and opportunities of fibre-reinforced polymers in additive manufacturing with focus on industrial applications

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pedersen, David Bue; Tosello, Guido

    2017-01-01

    Functional parts made by additive manufacturing of polymers have entered the area of industrial applications in recent years providing a wide range of materials with various mechanical, thermal, and electrical properties. These additive manufacturing processes can be combined with known fibre......-reinforcements applying modified material parameters with the use of fibre-reinforced polymers. An increase of tensile strength and Young’s modulus result from the application of short fibres in a polymer matrix opening up perspectives for a variety of industrial applications such as injection moulding, biomedical...

  2. Fibres reinforced dentures investigated with en-face optical coherence tomography

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Hughes, Michael; Bradu, Adrian; Goguta, Luciana; Rominu, Mihai; Negru, Radu; Podoleanu, Adrian Gh.

    2008-04-01

    The complete dentures are currently made using different technologies. In order to avoid deficiencies of the prostheses made using the classical technique, several alternative procedures have been devised. In order to enhance the mechanical strength, complete denture bases are reinforced with fibres. Their material and structure vary wildly, which makes the investigation difficult. In this study, optical coherence tomography (OCT) is evaluated as a possible non-invasive technique to assess the biomechanical behaviour of the reinforcing fibres. OCT images demonstrate structural defects between fibres and the acrylic material in all dentures bases investigated. We conclude that OCT can successfully be used as a noninvasive analysis method.

  3. Thermomechanical response and toughening mechanisms of a carbon nano bead reinforced epoxy composite

    Energy Technology Data Exchange (ETDEWEB)

    Goyat, M.S., E-mail: goyatmanjeetsingh@gmail.com [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667 (India); Suresh, Sumit; Bahl, Sumit [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667 (India); Halder, Sudipta [Department of Mechanical Engineering, National Institute of Technology, Silchar, 788010, Assam (India); Ghosh, P.K. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667 (India)

    2015-09-15

    The current research on carbon nano beads (CNB) is focused on various applications such as high strength nanocomposites, electronic devices, lubricants, semiconductors, and high-performance batteries, etc. The commercial uses of CNB are yet juvenile for the market. Only limited results have been published so far on CNB reinforced polymers [1]. This study highlights the synthesis of uniform size, spherical CNB using chemical vapour deposition (CVD) method. The synthesized CNB are introduced into epoxy matrix by ultrasonic dual mode mixing route to produce CNB/epoxy nanocomposite. The CNB are characterized by X-ray diffraction, Energy dispersive X-ray analysis and field emission scanning electron microscope (FESEM). Morphology, thermal and mechanical properties of the CNB/epoxy nanocomposites is characterized by FESEM, Thermo-gravimetric analyzer and tensile and bending tests respectively. A noticeable improvement in thermal and mechanical properties of CNB reinforced epoxy matrix with low nanofiller content is observed. Several toughening mechanisms such as particle pull out, crack deflection, particle bridging, crack pinning, shear yielding or plastic deformation, and microcracking are identified. But, only the crack deflection, particle bridging and shear yielding or plastic deformations are recognized as the leading toughening mechanisms for CNB/epoxy nanocomposite. These results can be considered as symptomatic of a potential CNB espousal in new composites. - Highlights: • Synthesis of uniform size, spherical CNB using chemical vapour deposition method. • Fabrication of CNB/epoxy nanocomposites by ultrasonic dual mode mixing route. • Significant enhancement in thermomechanical properties of CNB/epoxy nanocomposite. • Main toughening mechanisms: Crack deflection, particle bridging and shear yielding.

  4. Effect of filler geometry on coefficient of thermal expansion in carbon nanofiber reinforced epoxy composites.

    Science.gov (United States)

    Cho, M; Jang, J; Suhr, J

    2011-02-01

    This study involves the investigation of the geometry effect of nano-fillers on thermally induced dimensional stability of epoxy composites by experimentally evaluating the linear coefficient of thermal expansion (CTE). Carbon nanofibers (CNF) were chosen as the filler in epoxy matrix to investigate the effect of an aspect ratio on the CTE of the nanocomposites at three different volume fractions of 0.5, 1, and 2% of the nano-filler. The composites were fabricated using a mechanical mixing method. The CTE values were evaluated by measuring thermal strains of the composites and also compared with a micromechanics model. It was observed that the composites with short CNF (average L/d = 10) show better thermal stability than one of the composites with long CNF (average L/d = 70), and the thermal stability of the composites was proportional to the volume fraction of the filler in each composite. In addition, the CTE of mutliwalled carbon nanotubes (MWNT) reinforced epoxy composites was evaluated and compared with the CTE of the CNF reinforced composites. Interestingly, the MWNT reinforced composites show the greatest thermal stability with an 11.5% reduction in the CTE over the pure epoxy. The experimental data was compared with micromechanics model.

  5. Imidazolium Ionic Liquid Modified Graphene Oxide: As a Reinforcing Filler and Catalyst in Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Qing Lyu

    2017-09-01

    Full Text Available Surface modification of graphene oxide (GO is one of the most important issues to produce high performance GO/epoxy composites. In this paper, the imidazole ionic liquid (IMD-Si was introduced onto the surface of GO sheets by a cheap and simple method, to prepare a reinforcing filler, as well as a catalyst in epoxy resin. The interlayer spacing of GO sheets was obviously increased by the intercalation of IMD-Si, which strongly facilitated the dispersibility of graphene oxide in organic solvents and epoxy matrix. The addition of 0.4 wt % imidazolium ionic liquid modified graphene oxide (IMD-Si@GO, yielded a 12% increase in flexural strength (141.3 MPa, a 26% increase in flexural modulus (4.69 GPa, and a 52% increase in impact strength (18.7 kJ/m2, compared to the neat epoxy. Additionally the IMD-Si@GO sheets could catalyze the curing reaction of epoxy resin-anhydride system significantly. Moreover, the improved thermal conductivities and thermal stabilities of epoxy composites filled with IMD-Si@GO were also demonstrated.

  6. Optimizing the Processing Conditions for the Reinforcement of Epoxy Resin by Multi walled Carbon Nano tubes

    International Nuclear Information System (INIS)

    Arun, S.; Maharana, M.; Kanagaraj, S.

    2013-01-01

    The reinforcement of epoxy by MWCNTs is done to obtain the required properties of composites. However, the homogeneous dispersion of MWCNTs in epoxy is a critical problem. Hence, an attempt is made to optimize the processing conditions for dispersing the MWCNTs in epoxy by solvent dispersion technique. The epoxy/MWCNTs mixture was prepared using three methods: (1) magnetic stirring at 55°C, (2) hot air oven process at 55°C, and (3) vacuum oven process at room temperature. The nano composites having 0.1 and 0.2 wt.% of MWCNTs were prepared, for each method. The mechanical properties of nano composites were studied as per ASTM-D695, and the thermal conductivity was measured using KD2 probe. It is observed that the compressive strength, Young’s modulus, and thermal conductivity of 0.2 wt.% of MWCNTs prepared by vacuum oven method were found to be enhanced by 39.4, 10.7, and 59.2%, respectively, compared to those of pure epoxy. Though the properties of nano composites were increased with MWCNTs’ concentration irrespective of the processing techniques, the vacuum-processed sample showed the most enhanced properties compared to any other method. It is concluded that a unique method for the dispersion of MWCNTs in epoxy is the solvent dispersion technique with vacuum drying process.

  7. Short and long carbon fibre reinforced Cu-matrix composites: microstructural results and structural origin of properties

    International Nuclear Information System (INIS)

    Buchgraber, W.

    1997-01-01

    Carbon fibre reinforced copper matrix composites possess properties of copper, i.e. excellent thermal and electrical conductivities, and properties of carbon fibre, i.e. a small thermal expansion coefficient. Since the desirable properties of the composite can be obtained by selecting the amount, type and orientation of the carbon fibres, it is considered to be suitable for use as electric and electronic materials. This lecture focuses on two-dimensional isotropic carbon fibre reinforced copper matrix composites with long or short carbon fibres. Short carbon fibre reinforced copper matrix composites have been produced by hot-pressing of copper coated short carbon fibres. During hot-pressing, the carbon fibres take on a preferred orientation in a plane perpendicular to the hot pressing direction. Within this plane the fibre orientation is random. Long carbon fibre reinforced copper matrix composites have been made by hot pressing of monolayers consisting of copper coated long carbon fibres. Different orientations of the monolayers will be compared. Both the physical and mechanical properties of the discussed composites are strongly influenced not only by the properties of its individual constituents, but also by the microstructure and properties of the fibre matrix interface. The problem of poor wettability of the carbon fibre by the copper matrix will be discussed. The microstructure of several types of carbon fibre reinforced copper matrix composites will be discussed. Their thermophysical properties will be compared with microstructural results. (author)

  8. Controlled retting of hemp fibres: Effect of hydrothermal pre-treatmen tand enzymatic retting on the mechanical properties of unidirectiona lhemp/epoxy composites

    DEFF Research Database (Denmark)

    Liu, Ming; Silva, Diogo Alexandre Santos; Fernando, Dinesh

    2016-01-01

    The objective of this work was to investigate the use of hydrothermal pre-treatment and enzymatic retting to remove non-cellulosic compounds and thus improve the mechanical properties of hemp fibre/epoxy composites. Hydrothermal pre-treatment at 100 kPa and 121 °C combined with enzymatic retting...... produced fibres with the highest ultimate tensile strength (UTS) of 780 MPa. Compared to untreated fibres, this combined treatment exhibited a positive effect on the mechanical properties of hemp fibre/epoxy composites, resulting in high quality composites with low porosity factor (αpf) of 0.08.Traditional...

  9. Design and fabrication of the PDX poloidal field solenoid utilizing fiberglass reinforced epoxy

    International Nuclear Information System (INIS)

    Young, K.S.C.

    1975-11-01

    This paper discusses the basic design of the Poloidal Field Solenoid Coil. It will be mainly concerned with the more unique features of the Solenoid such as the copper coil windings and the design of the epoxy-glass structural support mandrels. The center solenoid coil of the PDX machine consists of five different coil systems (OH No. 8, No. 9; NF No. 11; DF No. 7; EF Solenoid and CF No. 9). Three concentric fiberglass reinforced epoxy cylinders fabricated in-house will act as mandrels to support and to house the coils that will result as an integral unit

  10. Strength and toughness of structural fibres for composite material reinforcement.

    Science.gov (United States)

    Herráez, M; Fernández, A; Lopes, C S; González, C

    2016-07-13

    The characterization of the strength and fracture toughness of three common structural fibres, E-glass, AS4 carbon and Kevlar KM2, is presented in this work. The notched specimens were prepared by means of selective carving of individual fibres by means of the focused ion beam. A straight-fronted edge notch was introduced in a plane perpendicular to the fibre axis, with the relative notch depth being a0/D≈0.1 and the notch radius at the tip approximately 50 nm. The selection of the appropriate beam current during milling operations was performed to avoid to as much as possible any microstructural changes owing to ion impingement. Both notched and un-notched fibres were submitted to uniaxial tensile tests up to failure. The strength of the un-notched fibres was characterized in terms of the Weibull statistics, whereas the residual strength of the notched fibres was used to determine their apparent toughness. To this end, the stress intensity factor of a fronted edge crack was computed by means of the finite-element method for different crack lengths. The experimental results agreed with those reported in the literature for polyacrylonitrile-based carbon fibres obtained by using similar techniques. After mechanical testing, the fracture surface of the fibres was analysed to ascertain the failure mechanisms. It was found that AS4 carbon and E-glass fibres presented the lower toughness with fracture surfaces perpendicular to the fibre axis, emanating from the notch tip. The fractured region of Kevlar KM2 fibres extended along the fibre and showed large permanent deformation, which explains their higher degree of toughness when compared with carbon and glass fibres. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. © 2016 The Author(s).

  11. Dimensional change of acrylic resin plate after the reinforcement of glass fibre

    Directory of Open Access Journals (Sweden)

    Dwiyanti Feriana Ratwita

    2007-06-01

    Full Text Available The effect of fibre reinforcement of polymethyl methacrylate was investigated. Glass fibres have been studied as strengthening material added to polymethyl methacrylate. The purpose of this study was to evaluate dimensional change of acrylic resin plate after glass fibre reinforcement. As a research subject is an acrylic resin plate of 65 × 10 × 2.5 mm with the number of 32 samples were distributed randomly in 4 experimental groups. Each group consisted of 8 samples and control groups. Group 1: acrylic resin plate and 1 sheet glass fibre; group 2: acrylic resin plate and 2 sheet glass fibre; group 3: acrylic resin plate and 3 sheet glass fibre. Control group which was not given treatment. Dimensional change was measured by profile projector. The data was analyzed by One-Way ANOVA and LSD test showed that there was significant difference in dimensional change (p < 0.005. The conclusion suggested that dimensional change of the acrylic resin plates after glass fibre reinforcement minimally done 1 sheet glass fibre.

  12. VALIDATION AND IMPLEMENTATION OF FAILURE PARAMETERS IN INTEGRATED SIMULATIONS FOR SHORT FIBRE REINFORCED POLYPROPYLENE

    Directory of Open Access Journals (Sweden)

    Anna Kalteis

    2016-12-01

    Full Text Available Nowadays short fibre reinforced polymers are often used in load carrying structural parts. Compared to continuous fibre reinforced polymers they exhibit a more complex morphology. Hence the determination of the strength is a difficult but important task. Therefore this was the objective of this research. The strength of short fibre reinforced polymers was numerically determined for low-speed to high-speed strain rates for specimens with different fibre orientations. For the failure modelling the micromechanical approach “First pseudo grain failure” in Digimat was used. The parameters for the material and failure description were determined with the reverse engineering method. Integrated finite element simulationswere performed to validate the material and failure models by tensile and bending tests with different specimens. The comparison of the results of the experiments and simulations showed low deviation.

  13. Analysis of acoustic emission cumulative signal strength of steel fibre reinforced concrete (SFRC) beams strengthened with carbon fibre reinforced polymer (CFRP)

    Science.gov (United States)

    Abdul Hakeem, Z.; Noorsuhada, M. N.; Azmi, I.; Noor Syafeekha, M. S.; Soffian Noor, M. S.

    2017-12-01

    In this study, steel fibre reinforced concrete (SFRC) beams strengthened with carbon fibre reinforced polymer (CFRP) were investigated using acoustic emission (AE) technique. Three beams with dimension of 150 mm width, 200 mm depth and 1500 mm length were fabricated. The results generated from AE parameters were analysed as well as signal strength and cumulative signal strength. Three relationships were produced namely load versus deflection, signal strength versus time and cumulative signal strength with respect to time. Each relationship indicates significant physical behaviour as the crack propagated in the beams. It is found that an addition of steel fibre in the concrete mix and strengthening of CFRP increase the ultimate load of the beam and the activity of signal strength. Moreover, the highest signal strength generated can be identified. From the study, the occurrence of crack in the beam can be predicted using AE signal strength.

  14. Reflection of plane waves at the free surface of a fibre-reinforced ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. The propagation of plane waves in fibre-reinforced, anisotropic, elas- tic media is discussed. The expressions for the phase velocity of quasi-P (qP) and quasi-SV (qSV) waves propagating in a plane containing the reinforcement direction are obtained as functions of the angle between the propagation and rein-.

  15. A two-dimensional problem for a fibre-reinforced anisotropic ...

    Indian Academy of Sciences (India)

    dicted by Green–Naghdi theory of the two types (GNII without energy dissipation) and (GNIII with energy dissipation). We found that the reinforcement has great effect on the distribution of field quantities. Results carried out in this paper can be used to design various fibre-reinforced anisotropic thermoelastic elements under ...

  16. A built-in sensor with carbon nanotubes coated by Ag clusters for deformation monitoring of glass fibre/epoxy composites

    Science.gov (United States)

    Slobodian, P.; Riha, P.; Matyas, J.; Olejnik, R.; Lloret Pertegás, S.; Schledjewski, R.; Kovar, M.

    2018-03-01

    A multiwalled carbon nanotube network embedded in a polyurethane membrane was integrated into a glass fibre reinforced epoxy composite by means of vacuum infusion to become a part of the composite and has been serving for a strain self-sensing functionality. Besides the pristine nanotubes also nanotubes with Ag nanoparticles attached to their surfaces were used to increase strain sensing. Moreover, the design of the carbon nanotube/polyurethane sensor allowed formation of network micro-sized cracks which increased its reversible electrical resistance resulted in an enhancement of strain sensing. The resistance sensitivity, quantified by a gauge factor, increased more than hundredfold in case of a pre-strained sensor with Ag decorated nanotubes in comparison with the sensor with pristine nanotubes.

  17. Determination of material properties for short fibre reinforced C/C-SiC

    Directory of Open Access Journals (Sweden)

    Hausherr J.-M.

    2015-01-01

    Full Text Available Determining the mechanical properties of short fibre reinforced CMC using standard sized coupons has always been a challenge due to a high statistical scattering of the measured values. Although the random orientation of short fibres results in a quasi-isotropic material behavior of 2D-structures with a sufficiently large volume, the small volume typical for test coupons usually results in a non-isotropic fibre orientation in the tested volume. This paper describes a method for manufacturing unidirectional oriented short fibre reinforced CMC materials and presents material properties of UD-C/C-SiC. After verifying the fibre orientation of the CMC using micro-computed tomography, coupons were extracted to determine the orthotropic material properties. These orthotropic material properties were then used to predict the properties of C/C-SiC with randomly distributed short fibres. To validate the method, micro-computed tomography is used to quantitatively determine the fibre orientation within coupons extracted from randomly distributed short fibre C/C-SiC. After mechanical three-point-bending tests, the measured stiffness and bending strength is compared with the predicted properties. Finally, the data are used to devise a method suited for reducing the inherent large spread of material properties associated with the measurement of CMC materials with randomly distributed short fibres.

  18. Replacement of minimum steel bar reinforcement with steel fibres in structural concrete members

    Science.gov (United States)

    Junker, F.; Holschemacher, K.; Müller, T.; Kieslich, H.

    2017-09-01

    Using lightweight concrete enables a decrease in dead load and thermal conductivity in the case of the manufacturing of structural concrete members. With the addition of steel fibres in concrete, its properties are altered from brittle to ductile, so that the use of additional minimum reinforcement for securing ductility and crack control can be avoided. This study is aimed at investigating the possibility of replacing conventional minimum steel bar reinforcement with steel fibre reinforcement in lightweight aggregate concrete under flexural loading. Therefore, six full-scaled beams with two different lightweight aggregate concretes (LWAC) (oven-dry densities of beam with traditional steel bars, a beam with steel fibres and a beam with a combination of steel fibre reinforcement and reduced steel bar reinforcement were produced. The cracking behaviour of the lightweight concrete beams was studied in a four-point bending test. The results of this study show that it is possible to replace a high amount of the conventional mesh or bar reinforcement with steel fibres.

  19. Preparation and characterization of carbon nanotube-hybridized carbon fiber to reinforce epoxy composite

    International Nuclear Information System (INIS)

    An, Feng; Lu, Chunxiang; Li, Yonghong; Guo, Jinhai; Lu, Xiaoxuan; Lu, Huibin; He, Shuqing; Yang, Yu

    2012-01-01

    Highlights: → CNTs were uniformly grown onto the carbon fibers. → No obvious mechanical properties of carbon fiber were observed after CNT growth. → The IFSS of multiscale epoxy composite was measured by single fiber pull-out tests. → Observing fractography of composite, the fracture modes of CNTs were discussed. -- Abstract: The multiscale carbon nanotube-hybridized carbon fiber was prepared by a newly developed aerosol-assisted chemical vapour deposition. Scanning electron microscopy and transmission electron microscope were carried out to characterize this multiscale material. Compared with the original carbon fibers, the fabrication of this hybrid fiber resulted in an almost threefold increase of BET surface area to reach 2.22 m 2 /g. Meanwhile, there was a slight degradation of fiber tensile strength within 10%, while the fiber modulus was not significantly affected. The interfacial shearing strength of a carbon fiber-reinforced polymer composite with carbon nanotube-hybridized carbon fiber and an epoxy matrix was determined from the single fiber pull-out tests of microdroplet composite. Due to an efficient increase of load transfer at the fiber/matrix interfaces, the interracial shear strength of composite reinforced by carbon nanotube-hybridized carbon fiber is almost 94% higher than that of one reinforced by the original carbon fiber. Based on the fractured morphologies of the composites, the interfacial reinforcing mechanisms were discussed through proposing different types of carbon nanotube fracture modes along with fiber pulling out from epoxy composites.

  20. Corrosion protection performance of corrosion inhibitors and epoxy-coated reinforcing steel in a simulated concrete pore water solution.

    Science.gov (United States)

    1998-06-01

    We used a simulated concrete pore water solution to evaluate the corrosion protection performance of concrete corrosion-inhibiting admixtures and epoxy-coated reinforcing bars (ECR). We evaluated three commercial corrosion inhibitors, ECR from three ...

  1. Cellulose kraft pulp reinforced polylactic acid (PLA composites: effect of fibre moisture content

    Directory of Open Access Journals (Sweden)

    Elias Retulainen

    2016-06-01

    Full Text Available PLA offers a competitive and CO2 neutral matrix to commonly used polyolefin polymer based composites. Moreover, the use of PLA reduces dependency on oil when producing composite materials. However, PLA has a tendency of hydrolytic degradation under melt processing conditions in the presence of moisture, which remains a challenge when processing PLA reinforced natural fibre composites. Natural fibres such as cellulose fibres are hygroscopic with 6–10 wt% moisture content at 50–70% relative humidity conditions. These fibres are sensitive to melt processing conditions and fibre breakage (cutting also occur during processing. The degradation of PLA, moisture absorption of natural fibres together with fibre cutting and uneven dispersion of fibres in polymer matrix, deteriorates the overall properties of the composite. In the given research paper, bleached softwood kraft pulp (BSKP reinforced PLA compounds were successfully melt processed using BSKP with relatively high moisture contents. The effect of moist BSKP on the molecular weight of PLA, fibre length and the mechanical properties of the composites were investigated. By using moist never-dried kraft pulp fibres for feeding, the fibre cutting was decreased during the melt compounding. Even though PLA degradation occurred during the melt processing, the final damage to the PLA was moderate and thus did not deteriorate the mechanical properties of the composites. However, comprehensive moisture removal is required during the compounding in order to achieve optimal overall performance of the PLA/BSKP composites. The economic benefit gained from using moist BSKP is that the expensive and time consuming drying process steps of the kraft pulp fibres prior to processing can be minimized.

  2. Comparison of tensile strength of different carbon fabric reinforced epoxy composites

    Directory of Open Access Journals (Sweden)

    Jane Maria Faulstich de Paiva

    2006-03-01

    Full Text Available Carbon fabric/epoxy composites are materials used in aeronautical industry to manufacture several components as flaps, aileron, landing-gear doors and others. To evaluate these materials become important to know their mechanical properties, for example, the tensile strength. Tensile tests are usually performed in aeronautical industry to determinate tensile property data for material specifications, quality assurance and structural analysis. For this work, it was manufactured four different laminate families (F155/PW, F155/HS, F584/PW and F584/HS using pre-impregnated materials (prepregs based on F155TM and F584TM epoxy resins reinforced with carbon fiber fabric styles Plain Weave (PW and Eight Harness Satin (8HS. The matrix F155TM code is an epoxy resin type DGEBA (diglycidil ether of bisphenol A that contains a curing agent and the F584TM code is a modified epoxy resin type. The laminates were obtained by handing lay-up process following an appropriate curing cycle in autoclave. The samples were evaluated by tensile tests according to the ASTM D3039. The F584/PW laminates presented the highest values of tensile strength. However, the highest modulus results were determined for the 8HS composite laminates. The correlation of these results emphasizes the importance of the adequate combination of the polymeric matrix and the reinforcement arrangement in the structural composite manufacture. The microscopic analyses of the tested specimens show valid failure modes for composites used in aeronautical industry.

  3. Mechanical, degradation and cytocompatibility properties of magnesium coated phosphate glass fibre reinforced polycaprolactone composites.

    Science.gov (United States)

    Liu, Xiaoling; Hasan, Muhammad S; Grant, David M; Harper, Lee T; Parsons, Andrew J; Palmer, Graham; Rudd, Chris D; Ahmed, Ifty

    2014-11-01

    Retention of mechanical properties of phosphate glass fibre reinforced degradable polyesters such as polycaprolactone and polylactic acid in aqueous media has been shown to be strongly influenced by the integrity of the fibre/polymer interface. A previous study utilising 'single fibre' fragmentation tests found that coating with magnesium improved the fibre and matrix interfacial shear strength. Therefore, the aim of this study was to investigate the effects of a magnesium coating on the manufacture and characterisation of a random chopped fibre reinforced polycaprolactone composite. Short chopped strand non-woven phosphate glass fibre mats were sputter coated with degradable magnesium to manufacture phosphate glass fibre/polycaprolactone composites. The degradation behaviour (water uptake, mass loss and pH change of the media) of these polycaprolactone composites as well as of pure polycaprolactone was investigated in phosphate buffered saline. The Mg coated fibre reinforced composites revealed less water uptake and mass loss during degradation compared to the non-coated composites. The cations released were also explored and a lower ion release profile for all three cations investigated (namely Na(+), Mg(2+) and Ca(2+)) was seen for the Mg coated composite samples. An increase of 17% in tensile strength and 47% in tensile modulus was obtained for the Mg coated composite samples. Both flexural and tensile properties were investigated and a higher retention of mechanical properties was obtained for the Mg coated fibre reinforced composite samples up to 10 days immersion in PBS. Cytocompatibility study showed both composite samples (coated and non-coated) had good cytocompatibility with human osteosarcoma cell line. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  4. Izod Impact Test in Epoxi Matrix Composites Reinforced with Hemp Fiber

    Science.gov (United States)

    Rohen, Lázaro A.; Margem, Frederico M.; Neves, Anna C. C.; Monteiro, Sérgio N.; Gomes, Maycon A.; de Castro, Rafael G.; Maurício, F. V. Carlos; de Paula, Fernanda

    Synthetic fiber has been gradually replaced by natural fiber, such as lignocellulosic fiber. In comparison with synthetic fiber, natural fiber has shown economic and environmental advantages. The natural fiber presents interfacial characteristics with polymeric matrices that favor a high impact energy absorption by the composite structure. However, until now little has been evaluated about the hemp fiber incorporated in polymeric matrices. This study has the purpose of evaluate the impact resistance of this kind of epoxy matrix composite reinforced with different percentages of hemp fibers. The impact resistance has substantially increased the relative amount of hemp fiber incorporated as reinforcement in the composite. This performance was associated with the difficulty of rupture imposed by the fibers resulting from the interaction of hemp fiber / epoxy matrix that helps absorb the impact energy.

  5. Two-dimensional magnesium oxide nanosheets reinforced epoxy nanocomposites for enhanced fracture toughness

    Science.gov (United States)

    Balguri, Praveen Kumar; Harris Samuel, D. G.; Guruvishnu, T.; Aditya, D. B.; Mahadevan, S. M.; Thumu, Udayabhaskararao

    2018-01-01

    Metal oxide nanoparticles have been used as excellent reinforcements to enhance mechanical properties of polymers, natural composites, and ceramics. To date, a major portion of metal oxides used as nanofillers is three dimensional spherical nanoparticles. In the last decade, two-dimensional (2D) materials such as graphene have been widely investigated to improve the mechanical and electrical properties of polymer materials. In this paper, 2D Magnesium oxide (MgO) nanosheets reinforced epoxy composites (0.1, 0.2 and 0.4 wt%) are fabricated and studied for their ability to resist the propagation of preexisting flaw by conducting fracture toughness test for K IC, critical stress intensity factor. This property is an important mechanical property for designing applications in various engineering technologies. Our results show that the MgO with 0.2 wt% is the optimized level to improve the fracture toughness of the epoxy polymer by 47%.

  6. Mechanical characterization of epoxy composite with multiscale reinforcements: Carbon nanotubes and short carbon fibers

    International Nuclear Information System (INIS)

    Rahmanian, S.; Suraya, A.R.; Shazed, M.A.; Zahari, R.; Zainudin, E.S.

    2014-01-01

    Highlights: • Multiscale composite was prepared by incorporation of carbon nanotubes and fibers. • Carbon nanotubes were also grown on short carbon fibers to enhance stress transfer. • Significant improvements were achieved in mechanical properties of composites. • Synergic effect of carbon nanotubes and fibers was demonstrated. - Abstract: Carbon nanotubes (CNT) and short carbon fibers were incorporated into an epoxy matrix to fabricate a high performance multiscale composite. To improve the stress transfer between epoxy and carbon fibers, CNT were also grown on fibers through chemical vapor deposition (CVD) method to produce CNT grown short carbon fibers (CSCF). Mechanical characterization of composites was performed to investigate the synergy effects of CNT and CSCF in the epoxy matrix. The multiscale composites revealed significant improvement in elastic and storage modulus, strength as well as impact resistance in comparison to CNT–epoxy or CSCF–epoxy composites. An optimum content of CNT was found which provided the maximum stiffness and strength. The synergic reinforcing effects of combined fillers were analyzed on the fracture surface of composites through optical and scanning electron microscopy (SEM)

  7. Effect of Curing Period on Properties of Steel and Polypropylene Fibre Reinforced Ultra-High Performance Concrete

    Science.gov (United States)

    Smarzewski, Piotr

    2017-10-01

    This study has investigated the effect of curing period on the mechanical properties of straight polypropylene and hooked-end steel fibre reinforced ultra-high performance concrete (UHPC). Various physical properties are evaluated, i.e. absorbability, apparent density and open porosity. Compressive strength, tensile splitting strength, flexural strength and modulus of elasticity were determined at 28, 56 and 730 days. Comparative strength development of fibre reinforced mixes at 0.5%, 1%, 1.5% and 2% by volume fractions in relation to the mix without fibres was observed. Good correlations between the compressive strength and the modulus of elasticity are established. Steel and polypropylene fibres significantly increased the compressive strength, tensile splitting strength, flexural strength and modulus of elasticity of UHPC after two years curing period when fibre content volume was at least 1%. It seems that steel fibre reinforced UHPC has better properties than the polypropylene fibre reinforced UHPC.

  8. Experimental Study on the Strength Characteristics and Water Permeability of Hybrid Steel Fibre Reinforced Concrete.

    Science.gov (United States)

    Singh, M P; Singh, S P; Singh, A P

    2014-01-01

    Results of an investigation conducted to study the effect of fibre hybridization on the strength characteristics such as compressive strength, split tensile strength, and water permeability of steel fibre reinforced concrete (SFRC) are presented. Steel fibres of different lengths, that is, 12.5 mm, 25 mm, and 50 mm, having constant diameter of 0.6 mm, were systematically combined in different mix proportions to obtain mono, binary, and ternary combinations at each of 0.5%, 1.0%, and 1.5% fibre volume fraction. A concrete mix containing no fibres was also cast for reference purpose. A total number of 1440 cube specimens of size 100∗100∗100 mm were tested, 480 each for compressive strength, split tensile strength, and water permeability at 7, 28, 90, and 120 days of curing. It has been observed from the results of this investigation that a fibre combination of 33% 12.5 mm + 33% 25 mm + 33% 50 mm long fibres can be adjudged as the most appropriate combination to be employed in hybrid steel fibre reinforced concrete (HySFRC) for optimum performance in terms of compressive strength, split tensile strength and water permeability requirements taken together.

  9. Effects of Hybrid Fibre Reinforcement on Fire Resistance Performance and Char Morphology of Intumescent Coating

    Directory of Open Access Journals (Sweden)

    Amir N.

    2016-01-01

    Full Text Available Recent researches of fire retardant intumescent coatings reinforced by single Rockwool and single glass wool fibre at various weight percentages and lengths showed some improvements to the mechanical properties of the coatings and the char produced. Therefore, in this research the fibres were combined together in intumescent coating formulation at several weight percentages and fibre lengths to study their effects towards fire resistance performance and char morphology. The hybrid fibre reinforced intumescent coatings were subjected to two types of fire tests; Bunsen burner at 1000°C and the electric furnace at 800°C for 1 hour, respectively. Steel temperature of the coated samples during Bunsen burner test was recorded to determine the fire resistance performance. Thermal stability of the intumescent coatings and chars was determined by Thermogravimetric Analysis (TGA. The morphology of the coatings and char was then examined by using Scanning Electron Microscopy (SEM and Energy Dispersive Spectrometry (EDS was conducted to obtain elemental composition of the samples. This research concluded that long-hybrid fibre at 12-mm length and 0.6% fibre-weight produced the top performing hybrid fibre intumescent formulation. The hybrid fibres form survived at elevated temperature, hence helped to provide structure and strengthen the char with the highest fire resistance was recorded at steel temperature of 197°C.

  10. Experimental Study on the Strength Characteristics and Water Permeability of Hybrid Steel Fibre Reinforced Concrete

    Science.gov (United States)

    Singh, M. P.; Singh, S. P.; Singh, A. P.

    2014-01-01

    Results of an investigation conducted to study the effect of fibre hybridization on the strength characteristics such as compressive strength, split tensile strength, and water permeability of steel fibre reinforced concrete (SFRC) are presented. Steel fibres of different lengths, that is, 12.5 mm, 25 mm, and 50 mm, having constant diameter of 0.6 mm, were systematically combined in different mix proportions to obtain mono, binary, and ternary combinations at each of 0.5%, 1.0%, and 1.5% fibre volume fraction. A concrete mix containing no fibres was also cast for reference purpose. A total number of 1440 cube specimens of size 100∗100∗100 mm were tested, 480 each for compressive strength, split tensile strength, and water permeability at 7, 28, 90, and 120 days of curing. It has been observed from the results of this investigation that a fibre combination of 33% 12.5 mm + 33% 25 mm + 33% 50 mm long fibres can be adjudged as the most appropriate combination to be employed in hybrid steel fibre reinforced concrete (HySFRC) for optimum performance in terms of compressive strength, split tensile strength and water permeability requirements taken together. PMID:27379298

  11. Graphene Oxide as Reinforcement in Epoxy Based Nanocomposites.

    OpenAIRE

    Svendsen, Elizabeth Martine

    2014-01-01

    Graphene oxide has received much attention in recent years because of its many promising properties. Graphene oxide can be used to produce graphene in large quantities, and in addition graphene oxide has many promising properties itself, such as its high level of dispersion in polar solvents, and good compatibility with various polymers. Addition of nanoparticles in composite materials have been tested for many years, and in recent years carbon nanotubes have been in focus as a reinforcement....

  12. Influence of the curing cycles on the fatigue performance of unidirectional glass fiber reinforced epoxy composites

    DEFF Research Database (Denmark)

    Hüther, Jonas; Brøndsted, Povl

    2016-01-01

    During the manufacturing process of fiber reinforced polymers the curing reaction of the resin results in shrinkage of the resin and introduces internal stresses in the composites. When curing at higher temperatures in order to shorten up the processing time, higher curing stresses and thermal...... stresses are built up and frozen, as residual stresses occur. In the present work, a glass fiber reinforced epoxy composite laminate with an unidirectional architecture based on non-crimp fabrics with backing fibers is investigated. Three different curing cycles (time-temperature cycles) are used, leading...

  13. Shear Strengthening of Corbels with Carbon Fibre Reinforced Polymers (CFRP

    Directory of Open Access Journals (Sweden)

    Nawaz, A.

    2010-09-01

    Full Text Available Corbels constitute what are known as “disturbed” regions in concrete structures, where typical shear failure may be anticipated on the grounds of small shear span-to-depth ratios. The concentration of stress induced by the weight of girders on the very small loadbearing areas in corbels often causes cracking in bridges and other structures. Little experimental research can be found in the literature on the shear strengthening of corbels. In the present study, nine such members were tested. Two had no carbon fibre reinforced polymers attached, while CFRP laminates were externally bonded to the other seven, in a number of different spatial arrangements. Ultimate shear strength was found and compared for all specimens. The results showed that CFRP configuration and geometry directly affected corbel shear strength, which was higher in all the CFRPstrengthened corbels than in the controls. The highest strength values were recorded for specimens whose shear-critical area was wrapped in CFRP.

    Las ménsulas constituyen lo que conocemos como regiones de “distorsión” en las estructuras de hormigón, zonas en que pueden preverse roturas por cortante debido a las bajas relaciones luz de cortante-canto presentes en ellas. La concentración de solicitaciones producida por el peso de las vigas sobre superficies de carga muy reducidas en las ménsulas a menudo provoca el agrietamiento de puentes y otras estructuras de obra civil. En la literatura especializada sobre el refuerzo a cortante de las ménsulas existen escasos ejemplos de estudios experimentales. Para la presente investigación se han realizado ensayos con nueve elementos de este tipo. Dos de ellos no incluían polímeros reforzados con fibra de carbono (CFRP, mientras que los siete restantes llevaban láminas externas de CFRP, dispuestas siguiendo distintas configuraciones espaciales. Los resultados indican que la configuración y la disposición geométrica de los CFRP repercuten

  14. Shrinkage Behaviour of Fibre Reinforced Concrete with Recycled Tyre Polymer Fibres

    OpenAIRE

    Marijana Serdar; Ana Baričević; Marija Jelčić Rukavina; Martina Pezer; Dubravka Bjegović; Nina Štirmer

    2015-01-01

    Different types of fibres are often used in concrete to prevent microcracking due to shrinkage, and polypropylene fibres are among the most often used ones. If not prevented, microcracks can lead to the development of larger cracks as drying shrinkage occurs, enabling penetration of aggressive substances from the environment and reducing durability of concrete structures. The hypothesis of the present research is that polypropylene fibres, used in concrete for controlling formation of microcr...

  15. Shrinkage Behaviour of Fibre Reinforced Concrete with Recycled Tyre Polymer Fibres

    Directory of Open Access Journals (Sweden)

    Marijana Serdar

    2015-01-01

    Full Text Available Different types of fibres are often used in concrete to prevent microcracking due to shrinkage, and polypropylene fibres are among the most often used ones. If not prevented, microcracks can lead to the development of larger cracks as drying shrinkage occurs, enabling penetration of aggressive substances from the environment and reducing durability of concrete structures. The hypothesis of the present research is that polypropylene fibres, used in concrete for controlling formation of microcracks due to shrinkage, can be replaced with recycled polymer fibres obtained from end-of-life tyres. To test the hypothesis, concrete mixtures containing polypropylene fibres and recycled tyre polymer fibres were prepared and tested. Experimental programme focused on autogenous, free, and restrained shrinkage. It was shown that PP fibres can be substituted with higher amount of recycled tyre polymer fibres obtaining concrete with similar shrinkage behaviour. The results indicate promising possibilities of using recycled tyre polymer fibres in concrete products. At the same time, such applications would contribute to solving the problem of waste tyre disposal.

  16. Corrosion resistance of steel fibre reinforced concrete – a literature review

    DEFF Research Database (Denmark)

    Marcos Meson, Victor; Michel, Alexander; Solgaard, Anders

    2016-01-01

    Steel fibre reinforced concrete (SFRC) is increasingly being used in the construction of prefabricated segmental linings for bored tunnels, since it entails simplified production processes and higher quality standards. However, international standards and guidelines are not consistent regarding...... literature concerning chloride-induced corrosion on steel fibres, as well as the impact of steel fibre corrosion on the residual-tensile strength of SFRC. The review confirms the agreement among academics and regulators regarding the superior durability of un-cracked SFRC exposed to chlorides, relative...... to conventional reinforcement. However, the durability of cracked SFRC is still under discussion, as the mechanisms governing the corrosion of carbon-steel fibres in cracks and its effects on the fracture behaviour of SFRC are still unclear. Nevertheless, there is insight among several researchers concerning...

  17. Finite element analysis of bond behavior in a steel reinforced concrete structure strengthened carbon fibre reinforced polymer (CFRP strips

    Directory of Open Access Journals (Sweden)

    P. Pastorek

    2017-01-01

    Full Text Available The article deals with the analysis of influence of carbon-fibre reinforced polymer (CFRP on stress distribution in a steel reinforced concrete beam loaded by four-point bending flexural test. Simulation of the delamination is modelled by FEM with a cohesion zone material model. Distribution of cracks with CFRP strengthening is analysed, too. Finally, the fatigue life tests analysis was executed for the steel specimen (W.Nr. 1.0429 – concrete steel, which was used in the reinforced concrete beam. The fatigue test results are used to plot the fatigue life curve.

  18. Preparation and characterization of glass fibers – polymers (epoxy bars (GFRP reinforced concrete for structural applications

    Directory of Open Access Journals (Sweden)

    Alkjk Saeed

    2016-06-01

    Full Text Available The paper presents some of the results from a large experimental program undertaken at the Department of Civil Engineering of Damascus University. The project aims to study the ability to reinforce and strengthen the concrete by bars from Epoxy polymer reinforced with glass fibers (GFRP and compared with reinforce concrete by steel bars in terms of mechanical properties. Five diameters of GFRP bars, and steel bars (4mm, 6mm, 8mm, 10mm, 12mm tested on tensile strength tests. The test shown that GFRP bars need tensile strength more than steel bars. The concrete beams measuring (15cm wide × 15cm deep × and 70cm long reinforced by GFRP with 0.5 vol.% ratio, then the concrete beams reinforced by steel with 0.89 vol.% ratio. The concrete beams tested on deflection test. The test shown that beams which reinforced by GFRP has higher deflection resistance, than beams which reinforced by steel. Which give more advantage to reinforced concrete by GFRP.

  19. Fibre Bragg grating sensors for reinforcement corrosion monitoring in civil engineering structures

    International Nuclear Information System (INIS)

    Grattan, S K T; Basheer, P; Taylor, S E; Zhao, W; Sun, T; Grattan, K T V

    2007-01-01

    Fibre optic strain sensors offer a number of advantages over the current electrical resistance type gauges, yet are not widely used in civil engineering applications. The use of fibre optic strain sensors (with a cross comparison with the output of electrical resistance gauges) to monitor the production of corrosion by-products in civil engineering concrete structures containing reinforcement bars has been investigated and results reported

  20. Corrosion resistance of steel fibre reinforced concrete – a literature review

    OpenAIRE

    Marcos Meson, Victor; Michel, Alexander; Solgaard, Anders; Fischer, Gregor; Edvardsen, Carola; Skovhus, Torben Lund

    2016-01-01

    Steel fibre reinforced concrete (SFRC) is increasingly being used in the construction of prefabricated segmental linings for bored tunnels, since it entails simplified production processes and higher quality standards. However, international standards and guidelines are not consistent regarding the consideration of steel fibres for the structural verification of SFRC elements exposed to corrosive environments, hampering the development of civil infrastructure built of SFRC. In particular, the...

  1. Behaviour of hybrid fibre reinforced concrete beam–column joints under reverse cyclic loads

    International Nuclear Information System (INIS)

    Ganesan, N.; Indira, P.V.; Sabeena, M.V.

    2014-01-01

    Highlights: • Developed a high performance hybrid fibre reinforced cementitious composite. • Exterior beam-column joints have been tested under reversed cyclic loading. • Ductility factor, energy dissipation and stiffness degradation have been evaluated. • Contribution to reduce congestion of reinforcement in beam column joints. - Abstract: An experimental investigation was carried out to study the effect of hybrid fibres on the strength and behaviour of High performance concrete beam column joints subjected to reverse cyclic loads. A total of 12 reinforced concrete beams column joints were cast and tested in the present investigation. High performance concrete of M60 grade was designed using the modified ACI method suggested by Aïtcin. Crimped steel fibres and polypropylene fibres were used in hybrid form. The main variables considered were the volume fraction of (i) crimped steel fibres viz. 0.5% (39.25 kg/m 3 ) and 1.0% (78.5 kg/m 3 ) and (ii) polypropylene fibres viz. 0.1% (0.9 kg/m 3 ), 0.15% (1.35 kg/m 3 ), and 0.2% (1.8 kg/m 3 ). Addition of fibres in hybrid form improved many of the engineering properties such as the first crack load, ultimate load and ductility factor of the composite. The combination of 1% (78.5 kg/m 3 ) volume fraction of steel fibres and 0.15% (1.35 kg/m 3 ) volume fraction of polypropylene fibres gave better performance with respect to energy dissipation capacity and stiffness degradation than the other combinations

  2. An exploration of the relationship of chemical and physical parameters in the micromechanical characterisation of the apparent interfacial strength in glass fibre epoxy systems

    Science.gov (United States)

    Thomason, J. L.; Yang, L.; Bryce, D.; Minty, R.

    2016-07-01

    This paper focuses on the cure shrinkage and the thermomechanical properties of an amine cured epoxy resin system and its adhesion to glass fibre. The fibre-matrix interfacial shear strength (IFSS) was characterized using the microbond test over a range of test temperatures and a range of amine:epoxy ratios. The apparent IFSS in this glass-epoxy system was shown to be strongly dependent on the testing temperature and the matrix stoichiometry. High levels of cure shrinkage were measured in the IFSS microdroplets which resulted in internal stresses causing significant levels of droplet deformation. The results presented here can be interpreted as providing further support for the hypothesis that a significant fraction of the interfacial stress transfer capability in epoxy composites can be attributed to a combination of residual radial compressive stress and static friction at the fibre-matrix interface.

  3. The influence of fibre orientation on the post-cracking tensile behaviour of steel fibre reinforced self-compacting concrete

    Directory of Open Access Journals (Sweden)

    A. Abrishambaf

    2015-01-01

    Full Text Available Adding fibres to concrete provides several advantages, especially in terms of controlling the crack opening width and propagation after the cracking onset. However, distribution and orientation of the fibres toward the active crack plane are significantly important in order to maximize its benefits. Therefore, in this study, the effect of the fibre distribution and orientation on the post-cracking tensile behaviour of the steel fibre reinforced self-compacting concrete (SFRSCC specimens is investigated. For this purpose, several cores were extracted from distinct locations of a panel and were subjected to indirect (splitting and direct tensile tests. The local stress-crack opening relationship (σ-w was obtained by modelling the splitting tensile test under the finite element framework and by performing an Inverse Analysis (IA procedure. Afterwards the σ-w law obtained from IA is then compared with the one ascertained directly from the uniaxial tensile tests. Finally, the fibre distribution/orientation parameters were determined adopting an image analysis technique.

  4. High strength oil palm shell concrete beams reinforced with steel fibres

    Directory of Open Access Journals (Sweden)

    S. Poh-Yap

    2017-10-01

    Full Text Available The utilization of lightweight oil palm shell to produce high strength lightweight sustainable material has led many researchers towards its commercialization as structural concrete. However, the low tensile strength of Oil Palm Shell Concrete (OPSC has hindered its development. This study aims to enhance the mechanical properties and flexural behaviours of OPSC by the addition of steel fibres of up to 3% by volume, to produce oil palm shell fibre-reinforced concrete (OPSFRC. The experimental results showed that the steel fibres significantly enhanced the mechanical properties of OPSFRC. The highest compressive strength, splitting tensile and flexural strengths of 55, 11.0 and 18.5 MPa, respectively, were achieved in the OPSFRC mix reinforced with 3% steel fibres. In addition, the flexural beam testing on OPSFRC beams with 3% steel fibres showed that the steel fibre reinforcement up to 3% produced notable increments in the moment capacity and crack resistance of OPSFRC beams, but accompanied by reduction in the ductility.

  5. Kenaf Fibre Reinforced Polypropylene Composites: Effect of Cyclic Immersion on Tensile Properties

    Directory of Open Access Journals (Sweden)

    W. H. Haniffah

    2015-01-01

    Full Text Available This research studied the degradation of tensile properties of kenaf fibre reinforced polypropylene composites due to cyclic immersion into two different solutions, as well as comparison of the developed composites’ tensile properties under continuous and cyclic immersion. Composites with 40% and 60% fibre loadings were immersed in tap water and bleach for 4 cycles. Each cycle consisted of 3 days of immersion and 4 days of conditioning in room temperature (28°C and 55% humidity. The tensile strength and modulus of composites were affected by fibre composition, type of liquid of immersion, and number of cycles. The number of immersion cycles and conditioning caused degradation to tensile strength and modulus of kenaf fibre reinforced polypropylene composites. Continuous and cyclic immersion in bleach caused tensile strength of the composites to differ significantly whereas, for tensile modulus, the difference was insignificant in any immersion and fibre loadings. However, continuous immersion in the bleach reduced the tensile strength of composites more compared to cyclic immersion. These preliminary results suggest further evaluation of the suitability of kenaf fibre reinforced polypropylene composites for potential bathroom application where the composites will be exposed to water/liquid in cyclic manner due to discontinuous usage of bathroom.

  6. Durability of cracked fibre reinforced concrete exposed to freeze-thaw and deicing salt

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    -thaw and deicing salt. The concrete has a water-powder ratio of 0.38 including both fly ash and silica fume. Both steel fibres (ZP, 0.4 vol%) and polypropylene fibres (PP, 1 vol%) are used as well as main reinforcement. The freeze-thaw test emphasizes the need for a critical evaluation of the mix design and mixing...... methods when designing FRC-structures. The scaling is increased by a factor 5 to 10 when adding fibres to the concrete while the air content is below 4% by volume. The variation of the scaling increases when adding fibres. Capillary water uptake in uncracked specimens of FRC was 20-30% higher at 1°C than...... at 20°C for both ZP- and PP-fibres, while the temperature had no effect on the water uptake in plain concrete.(This abstract is a short version of the published abstract)...

  7. Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads

    Directory of Open Access Journals (Sweden)

    Marco Romano

    2014-07-01

    Full Text Available This paper deals with experimental investigations concerning energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high-velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt fibres. Therefore test panels, using the same thermoset resin, were built up and cured by autoclave processing. The fibre volume content of the test panels has been determined. Furthermore the influence of a separating layer at selected positions in the hybrid stacked panels was investigated. The results show the influence and the energy dissipation capacity of each single kind of fibre and the enhanced properties for the hybrid layups by hybrid stacking sequences and the use of a separating core material.

  8. Treatments of non-wood plant fibres used as reinforcement in composite materials

    Directory of Open Access Journals (Sweden)

    Marie-Ange Arsène

    2013-01-01

    Full Text Available This paper presents a summary of the knowledge on fibres and pulps of non wood tropical plants used as reinforcement in cementitious composites accumulated during the recent years by Guadeloupean and Brazilian teams participating in collaborative work. Vegetable fibres represent a good alternative as non-conventional materials for the construction of ecological and sustainable buildings. The use of such renewable resources contributes to the development of sustainable technologies. The main objective of the paper is to emphasize the use of agricultural wastes in the production of cement based composites. The botanical, chemical, physical, morphological and mechanical properties of fibres from various plants are described. The effects of different treatments on physical, chemical and mechanical properties of fibres are presented. The most effective treatments in influencing the mechanical and physical properties are pyrolysis and alkaline ones, according to the type of plant. The final choice will have to consider fibre availability, and treatment costs.

  9. Post-cracking Behaviour and Fracture Energy of Synthetic Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Marta KOSIOR-KAZBERUK

    2016-11-01

    Full Text Available The paper reports the results of experimental programme focused on the effect of various synthetic fibres on fracture properties and ductility of concrete. The fracture energy was assessed on beams with initial notches in three-point bend test. The incorporation of synthetic fibres had a slight effect on mechanical properties of concrete but, at the same time, it had a significant influence on the fracture energy by modification of post-cracking behaviour of concrete. It was found that the modern synthetic fibres might be able to impart significant toughness and ductility to concrete. However, the beneficial effect of fibres depends on their length and flexibility. The analysis of load-deflection curves obtained made it possible to fit the simple function, describing the post-peak behaviour of fibre reinforced concrete, which can be useful for the calculation of GF value.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.13246

  10. Modelling and simulation of randomly oriented carbon fibre-reinforced composites under thermal load

    Science.gov (United States)

    Treffler, R.; Fröschl, J.; Drechsler, K.; Ladstätter, E.

    2016-03-01

    Carbon fibre-reinforced sheet moulding compounds (CF-SMC) already exhibit a complex material behaviour under uniaxial loads due to the random orientation of the fibres in the matrix resin. Mature material models for metallic materials are generally not transferable. This paper proposes an approach for modelling the fatigue behaviour of CF-SMC based on extensive static and cyclic tests using low cost secondary carbon fibres (SCF). The main focus is on describing the stiffness degradation considering the dynamic modulus of the material. Influence factors such as temperature, orientation, rate dependence and specimen thickness were additionally considered.

  11. Static and cyclic performance of cementitious composites reinforced with glass-fibres

    OpenAIRE

    Arabi , Nourredine

    2018-01-01

    International audience; This paper concerns an experimental study of the influence of short glass-fibres randomly oriented of a reinforced cement-based composite on the mechanical behaviour. The matrix material parameters used are: cement/sand ratio and water/cement ratio fixed at 0.5; the glass-fibre content (0%, 0.5%, 1.0%, 1.5%, 2% and 2.5%) and fibre lengths (3, 6 and 12 mm). Composites mechanical characterisation under static behaviour at flexural and compression tests, shows that the re...

  12. EFFECTIVE FRACTURE ENERGY OF ULTRA-HIGH-PERFORMANCE FIBRE-REINFORCED CONCRETE UNDER INCREASED STRAIN RATES

    Directory of Open Access Journals (Sweden)

    Radoslav Sovják

    2014-10-01

    Full Text Available The main objective of this paper is to contribute to the development of ultra-high performance fibre reinforced concrete (UHPFRC with respect to its effective fracture energy. Effective fracture energy was investigated in this paper considering different fibre volume fractions and different strain rates. It was concluded that the effective fracture energy is dependent on the strain rate. In addition, it was found that higher fibre volume fractions tend to decrease the sensitivity of the UHPFRC to increased strain rates.

  13. Low-weight Impact Behaviour of Carbon Fibre Reinforced Methyl Methacrylate Nanocomposites

    Directory of Open Access Journals (Sweden)

    Virginija Jankauskaitė

    2015-06-01

    Full Text Available Inthis study, the carbon fibre reinforced methyl methacrylate (CF/MMA compositetoecap for safety shoes was manufactured to increase the energy absorptioncapacity during impact. Different types of nanofillers such as organic andinorganic nanotubes, unmodified and organically modified nanoclays were appliedto modify matrix impact properties. The drop-weight impact tests of thenanocomposite toecap were performed with respect to nanofiller nature andcarbon fibre stacking sequence. It was found that the most influence on thestiffness and impact damage of the carbon fibre methyl methacrylatenanocomposite toecaps besides stacking sequence show organic and inorganic nanotubesor unmodified nanoclay.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.7075

  14. Mechanical properties of soil buried kenaf fibre reinforced thermoplastic polyurethane composites

    International Nuclear Information System (INIS)

    Sapuan, S.M.; Pua, Fei-ling; El-Shekeil, Y.A.; AL-Oqla, Faris M.

    2013-01-01

    Highlights: • We developed composites from kenaf and thermoplastic polyurethane. • Soil burial of composites after 80 days shows increase in flexural strength. • Soil burial of composites after 80 days shows increase in flexural modulus. • Tensile properties of composites degrade after soil burial tests. • We investigate the morphological fracture through scanning electron microscopy. - Abstract: A study on mechanical properties of soil buried kenaf fibre reinforced thermoplastic polyurethane (TPU) composites is presented in this paper. Kenaf bast fibre reinforced TPU composites were prepared via melt-mixing method using Haake Polydrive R600 internal mixer. The composites with 30% fibre loading were prepared based on some important parameters; i.e. 190 °C for reaction temperature, 11 min for reaction time and 400 rpm for rotating speed. The composites were subjected to soil burial tests where the purpose of these tests was to study the effect of moisture absorption on the mechanical properties of the composites. Tensile and flexural properties of the composites were determined before and after the soil burial tests for 20, 40, 60 and 80 days. The percentages of both moisture uptake and weight gain after soil burial tests were recorded. Tensile strength of kenaf fibre reinforced TPU composite dropped to ∼16.14 MPa after 80 days of soil burial test. It was also observed that there was no significant change in flexural properties of soil buried kenaf fibre reinforced TPU composite specimens

  15. Drilling analysis of coir–fibre-reinforced polyester composites

    Indian Academy of Sciences (India)

    Administrator

    mized for studying drilling characteristics of coir–polyester composites using the Taguchi approach. A drill bit diameter of 6 mm, spindle speed of 600 ... epoxy resin and made suggestions for low-load applica- tions. They assessed only the limited .... the multi-channel charge amplifier. A Rapid-I machine vision system from ...

  16. Tribological and mechanical behaviours of rattan-fibre-reinforced friction materials under dry sliding conditions

    Science.gov (United States)

    Ma, Yunhai; Wu, Siyang; Tong, Jin; Zhao, Xiaolou; Zhuang, Jian; Liu, Yucheng; Qi, Hongyan

    2018-03-01

    This work was mainly aimed to study the physical, mechanical and tribological behaviours of the friction materials reinforced by different contents of rattan fibre. These friction materials were fabricated by a compression moulder and tested using a constant speed tester at different friction temperatures. It was found that the friction coefficients of the friction materials added with rattan fibre were relatively stable and no obvious fade was observed in comparison with specimen F-0 (containing 0 wt.% rattan fibres). The fade ratio of specimen F-5 (containing 5 wt.% rattan fibres) was 10.3% and its recovery ratio was 92.4%, indicating the excellent performances of fade resistance and recovery. And the specimen F-5 exhibited the lowest wear rate (0.541 × 10‑7 cm3(N · m)‑1 at 350 °C) among all tested specimens. The worn surface morphologies of the friction materials showed that the appropriate addition of rattan fibres effectively reduced abrasive wear and adhesion wear. The specimen F-5 had a smooth worn surface (Sa = 1.885 μm) with the superior fibre-matrix interfacial adhesion and a lot of secondary contact plateaus, which indicated the highest wear resistance property. The rattan-fibre-reinforced friction materials could be widely applied to automotive friction brake field according to their economic, environmental and social benefits.

  17. Towards reinforcement solutions for urban fibre/fabric waste using bio-based biodegradable resins.

    Science.gov (United States)

    Agrawal, Pramod; Hermes, Alina; Bapeer, Solaf; Luiken, Anton; Bouwhuis, Gerrit; Brinks, Ger

    2017-10-01

    The main research question is how to systematically define and characterize urban textile waste and how to effectively utilise it to produce reinforcement(s) with selected bio-based biodegradable resin(s). Several composite samples have been produced utilising predominantly natural and predominantly synthetic fibres by combining loose fibres with PLA, nonwoven fabric with PLA, woven fabric with PLA, two-layer composite & four-layer composite samples. Physio-chemical characterisations according to the established standards have been conducted. The present work is a step toward the circular economy and closing the loop in textile value chain.

  18. The influence of powder liquid ratio on the flexural strength of fibre reinforced acrylic resin material.

    Science.gov (United States)

    Geerts, G A V M; du Rand, M

    2009-04-01

    Often the powder liquid (P/L) ratio of polymethyl methacrylate (PMMA) resins is changed to modify the handling properties of the material. While it is known that this may influence the mechanical properties of unreinforced PMMA resin, little is known about its effect on fibre reinforced resin. The purpose of this study was to determine how different P/L ratios influence the flexural strength (FS) of a glass fibre reinforced autopolymerizing PMMA resin used for fabricating fixed partial dentures. Two main groups of PMMA resin, 1 unreinforced and 1 reinforced with glass fibre, had 3 subgroups (n=21) each representing a different P/L ratio. The manufacturer's recommended ratio served as control. The specimens were prepared for a 3-point bending test. Using a universal testing machine, maximum force was recorded and the FS was calculated. Median FS values were compared by means of non-parametric analysis of variance (Kruskal-Wallis). A p-value of less than 0.05 was considered significant. FS values of all reinforced subgroups were significantly higher than the values of the unreinforced subgroups (p0.05). Within the reinforced group there was a significant difference between the control group, which had a higher median FS value than the two other subgroups (presin with glass fibre, it is important to use the recommended P/L ratio. For unreinforced PMMA resin the P/L ratio can be changed within limits without adverse effects on the FS.

  19. Experimentation and numerical simulation of steel fibre reinforced concrete pipes

    International Nuclear Information System (INIS)

    Fuente, A. de la; Domingues de Figueiredo, A.; Aguado, A.; Molins, C.; Chama Neto, P. J.

    2011-01-01

    The results concerning on an experimental and a numerical study related to SFRCP are presented. Eighteen pipes with an internal diameter of 600 mm and fibre dosages of 10, 20 and 40 kg/m3 were manufactured and tested. Some technological aspects were concluded. Likewise, a numerical parameterized model was implemented. With this model, the simulation of the resistant behaviour of SFRCP can be performed. In this sense, the results experimentally obtained were contrasted with those suggested by means MAP reaching very satisfactory correlations. Taking it into account, it could be said that the numerical model is a useful tool for the optimal design of the SFRCP fibre dosages, avoiding the need of the systematic employment of the test as an indirect design method. Consequently, the use of this model would reduce the overall cost of the pipes and would give fibres a boost as a solution for this structural typology. (Author) 27 refs.

  20. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation.

    Directory of Open Access Journals (Sweden)

    G F Pereira

    Full Text Available In a fibre-reinforced polymer (FRP structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material's mechanical properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics: the damage mechanism (delamination of FRP, the structural health monitoring technology (fibre Bragg gratings to detect delamination, and the finite element method model of the structure that incorporates these concepts into a final and integrated damage-monitoring concept. A novel method for assessing a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored by the end-user. Conjointly, a novel model for sensor output prediction (virtual sensor was developed using this FBG sensor crack monitoring concept and implemented in a finite element method code. The monitoring method was demonstrated and validated using glass fibre double cantilever beam specimens instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model.

  1. Strengthening Performance of PALF-Epoxy Composite Plate on Reinforced Concrete Beams

    Science.gov (United States)

    Chin, Siew C.; Tong, Foo S.; Doh, Shu I.; Gimbun, Jolius; Ong, Huey R.; Serigar, Januar P.

    2018-03-01

    This paper presents the effective strengthening potential of pineapple leaves fiber (PALF)-epoxy composite plate on reinforced concrete (RC) beam. At first the PALF is treated with alkali (NaOH) and its morphology is observed via scanning electron microscope (SEM). The composite plates made of PALF and epoxy with fiber loading ranging from 0.1 to 0.4 v/v was tested for its flexural behaviour. The composite was then used for external RC beam strengthening. The structural properties of RC beams were evaluated and all the beams were tested under four-point bending. It was found that the flexural strength increased as the fiber volume ratio increases. The maximum flexural strength (301.94 MPa) was obtained at the fiber volume ratio of 40%. The beam strengthened with PALF-epoxy composite plate has a 7% higher beam capacity compared to the control beam. Cracks formed at the edge of the plate of PALF-strengthened beams resulted in diagonal cracking. Result from this work shows that the PALF-epoxy composite plate has the potential to be used as external strengthening material for RC beam.

  2. Enhancement of mechanical and electrical properties of continuous-fiber-reinforced epoxy composites with stacked graphene

    Directory of Open Access Journals (Sweden)

    Naum Naveh

    2017-09-01

    Full Text Available Impregnation of expandable graphite (EG after thermal treatment with an epoxy resin containing surface-active agents (SAAs enhanced the intercalation of epoxy monomer between EG layers and led to further exfoliation of the graphite, resulting in stacks of few graphene layers, so-called “stacked” graphene (SG. This process enabled electrical conductivity of cured epoxy/SG composites at lower percolation thresholds, and improved thermo-mechanical properties were measured with either Kevlar, carbon or glass-fiber-reinforced composites. Several compositions with SAA-modified SG led to higher dynamic moduli especially at high temperatures, reflecting the better wetting ability of the modified nanoparticles. The hydrophilic/hydrophobic nature of the SAA dictates the surface energy balance. More hydrophilic SAAs promoted localization of the SG at the Kevlar/epoxy interface, and morphology seems to be driven by thermodynamics, rather than the kinetic effect of viscosity. This effect was less obvious with carbon or glass fibers, due to the lower surface energy of the carbon fibers or some incompatibility with the glass-fiber sizing. Proper choice of the surfactant and fine-tuning of the crosslink density at the interphase may provide further enhancements in thermo-mechanical behavior.

  3. A strategy for prediction of the elastic properties of epoxy-cellulose nanocrystal-reinforced fiber networks

    Science.gov (United States)

    Johnathan E. Goodsell; Robert J. Moon; Alionso Huizar; R. Byron Pipes

    2014-01-01

    The reinforcement potential of cellulose nanocrystal (CNC) additions on an idealized 2-dirmensional (2-D) fiber network structure consisting of micron sized fiber elements was investigated. The reinforcement mechanism considered in this study was through the stiffening of the micron sized fiber elements via a CNC-epoxy coating. A hierarchical analytical modeling...

  4. Chemical recycling of carbon fibers reinforced epoxy resin composites in oxygen in supercritical water

    International Nuclear Information System (INIS)

    Bai, Yongping; Wang, Zhi; Feng, Liqun

    2010-01-01

    The carbon fibers in carbon fibers reinforced epoxy resin composites were recovered in oxygen in supercritical water at 30 ± 1 MPa and 440 ± 10 o C. The microstructure of the recovered carbon fibers was observed using scanning electron microscopy (SEM) and atom force microscopy (AFM). The results revealed that the clean carbon fibers were recovered and had higher tensile strength relative to the virgin carbon fibers when the decomposition rate was above 85 wt.%, although the recovered carbon fibers have clean surface, the epoxy resin on the surface of the recovered carbon fibers was readily observed. As the decomposition rate increased to above 96 wt.%, no epoxy resin was observed on the surface of the carbon fibers and the oxidation of the recovered carbon fibers was readily measured by X-ray photoelectron spectroscopy (XPS) analysis. The carbon fibers were ideally recovered and have original strength when the decomposition rates were between 94 and 97 wt.%. This study clearly showed the oxygen in supercritical water is a promising way for recycling the carbon fibers in carbon fibers reinforced resin composites.

  5. Injection moulding of long glass fibre reinforced polyamide 6-6: guidelines to improve flexural properties

    Directory of Open Access Journals (Sweden)

    2007-07-01

    Full Text Available Based on a previous optimisation of set-up parameters for injection moulding of polyamide 6-6 (PA 6-6 reinforced with 40-wt% of 10 mm long glass fibre, the aim of this paper is to define suitable guidelines to further improve the mechanical performances of PA 6-6/glass long fibre thermoplastic (LFT injection mouldings. Different solutions have been considered: screw and non-return valve design modification so as to adapt them to LFT processing, increase of the initial fibre content (up to 50 wt% and length (up to 25 mm in the LFT pellets. Using a LFT dedicated plasticating unit has allowed decreasing the fibre breakage amount by about 80% at the nozzle exit, however without improving the flexural properties. Increasing the initial fibre content has logically permitted to improve the flexural properties. Increasing the initial fibre length has not brought any improvement of the properties and has even amplified the structural heterogeneities and anisotropy of the parts. These trends have been explained on the basis of cavity pressure records highlighting significantly different rheological behaviours, and of resulting residual fibre lengths and through-the-thickness fibre orientation profiles modifications.

  6. Evaluation of a Tramway’s Track Slab in Conventionally Reinforced Concrete or Steel Fibre Concrete

    OpenAIRE

    Zioris, Stavros; Vranjkovina, Alija

    2015-01-01

    The dominant reinforcement used widely for concrete structures is conventional steel bars (rebars). Nevertheless, the perpetual effort toward evolution and development could not exclude the engineering field, thus new innovative and sophisticated methods are introduced. It is true that, due to lack of extended regulations and standards, the fibre reinforced concrete (FRC) was limited to non-structural applications. However, the last years the situation is changing rapidly and already the appl...

  7. optimisation of thickness of fibre reinforced polymer sheets for ...

    African Journals Online (AJOL)

    The use of Fiber Reinforced Polymer (FRP) is becoming a widely accepted solution for repairing and strengthening of deteriorated reinforced concrete members, to restore their load carrying capacities. One of the major concerns in the use of FRP is its cost. This therefore calls for the use of efficient and cost effective design ...

  8. Synthesis of carbon fibre-reinforced, silicon carbide composites by ...

    Indian Academy of Sciences (India)

    to meet such challenges for preparing Cf-SiC as well as Cf-SiC with different additional phases .... phases in the concerned powders, suggesting hindrance to grain growth in the composites by the fibres and additional ... of the stress–strain curve for Cf-SiC unlike Cf-tow is considered to originate from matrix micro- cracking ...

  9. Continuous jute fibre reinforced laminated paper composite and ...

    Indian Academy of Sciences (India)

    Administrator

    Jute fibre; laminated paper composite; plastic bag pollution. 1. Introduction. Since the development of plastic in the ... that contaminate soils and water bodies and enter even the food chains. It may also be noted that a very ... poor tear resistance are major hurdles in their use as widely acceptable wrapping and packaging ...

  10. Effect of Moisture on Natural Fibre Reinforced Plastics.

    African Journals Online (AJOL)

    2016-12-01

    Dec 1, 2016 ... thermoplastic and thermoset matrix composites provide positive environmental benefits with respect to ultimate disposability and raw material utilization [6]. 2.0 Materials And Methods. The materials used in this work include: i. Ukam plant fibres (chochlostermum placoni) ii. Polyester resin. iii. Catalyst ...

  11. Behaviour of E-glass fibre reinforced vinylester resin composites ...

    Indian Academy of Sciences (India)

    Unknown

    (S–N) behaviour, having a progressive endurance below the threshold single cycle impact fracture stress with decreasing applied stress has been demonstrated. Fractographic analysis revealed fracture by primary debonding having fibre breakage ... fatigue life and stiffness reduction during fatigue loading. (Talreja 1985 ...

  12. Fatigue mechanisms in unidirectional glass-fibre-reinforced polypropylene

    DEFF Research Database (Denmark)

    Gamstedt, E.K.; Berglund, L.A.; Peijs, T.

    1999-01-01

    of stiffness reduction and fatigue-life curves. The results showed that the longitudinal Young's modulus degraded more rapidly for glass-fibre/PP, which was caused by a higher degree of damage growth and accumulation. The improvement in monotonic strength was negligible, but the fatigue life was prolonged...

  13. GLASS-FIBRE REINFORCED COMPOSITES: THE EFFECT OF ...

    African Journals Online (AJOL)

    HOD

    Application of polymer materials in many engineering application have enhanced the corrosion resistance and improved strength of many structures as witnessed in construction and building industries. Key of the factors that influence the properties of these composites are determined by fibre loading and orientation.

  14. Surface waves in fibre-reinforced anisotropic elastic media

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. Though the decoupling of displacement potentials in case of fibre- reinfoced anisotropic elastic media is not possible in the general case, an attempt has been made to decouple the equation as a particular case. The assumptions made in this paper satisfy both set of equations formed by the displacement ...

  15. Behaviour of E-glass fibre reinforced vinylester resin composites ...

    Indian Academy of Sciences (India)

    A well-defined impact fatigue (S–N) behaviour, having a progressive endurance below the threshold single cycle impact fracture stress with decreasing applied stress has been demonstrated. Fractographic analysis revealed fracture by primary debonding having fibre breakage and pullout at the tensile zone, but a shear ...

  16. Natural Mallow Fiber-Reinforced Epoxy Composite for Ballistic Armor Against Class III-A Ammunition

    Science.gov (United States)

    Nascimento, Lucio Fabio Cassiano; Holanda, Luane Isquerdo Ferreira; Louro, Luis Henrique Leme; Monteiro, Sergio Neves; Gomes, Alaelson Vieira; Lima, Édio Pereira

    2017-10-01

    Epoxy matrix composites reinforced with up to 30 vol pct of continuous and aligned natural mallow fibers were for the first time ballistic tested as personal armor against class III-A 9 mm FMJ ammunition. The ballistic efficiency of these composites was assessed by measuring the dissipated energy and residual velocity after the bullet perforation. The results were compared to those in similar tests of aramid fabric (Kevlar™) commonly used in vests for personal protections. Visual inspection and scanning electron microscopy analysis of impact-fractured samples revealed failure mechanisms associated with fiber pullout and rupture as well as epoxy cracking. As compared to Kevlar™, the mallow fiber composite displayed practically the same ballistic efficiency. However, there is a reduction in both weight and cost, which makes the mallow fiber composites a promising material for personal ballistic protection.

  17. Water Absorption Behaviour and Its Effect on the Mechanical Properties of Flax Fibre Reinforced Bioepoxy Composites

    Directory of Open Access Journals (Sweden)

    E. Muñoz

    2015-01-01

    Full Text Available In the context of sustainable development, considerable interest is being shown in the use of natural fibres like as reinforcement in polymer composites and in the development of resins from renewable resources. This paper focuses on eco-friendly and sustainable green composites manufacturing using resin transfer moulding (RTM process. Flax fibre reinforced bioepoxy composites at different weight fractions (40 and 55 wt% were prepared in order to study the effect of water absorption on their mechanical properties. Water absorption test was carried out by immersion specimens in water bath at room temperature for a time duration. The process of water absorption of these composites was found to approach Fickian diffusion behavior. Diffusion coefficients and maximum water uptake values were evaluated; the results showed that both increased with an increase in fibre content. Tensile and flexural properties of water immersed specimens were evaluated and compared to dry composite specimens. The results suggest that swelling of flax fibres due to water absorption can have positive effects on mechanical properties of the composite material. The results of this study showed that RTM process could be used to manufacture natural fibre reinforced composites with good mechanical properties even for potential applications in a humid environment.

  18. Corn gluten meal as a biodegradable matrix material in wood fibre reinforced composites

    Energy Technology Data Exchange (ETDEWEB)

    Beg, M.D.H. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand); Pickering, K.L. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand)]. E-mail: klp@waikato.ac.nz; Weal, S.J. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand)

    2005-12-05

    This study was undertaken to investigate corn gluten meal (CGM) as a biodegradable matrix material for wood fibre reinforced composites. CGM was used alone, as well as hybridized with polypropylene, and reinforced with radiata pine (Pinus Radiata) fibre using a twin-screw extruder followed by injection moulding. Tensile testing, scanning electron microscopy and differential scanning calorimetry were carried out to assess the composites. For composites from CGM and wood fibres, extrusion was carried out with the aid of the following plasticizers: octanoic acid, glycerol, polyethylene glycol and water. Windows of processability for the different plasticizers were obtained for all plasticizers. These were found to lie between 20 and 50 wt.% of plasticizer with a maximum of approximately 20% wood fibre reinforcement. The best mechanical properties were obtained with a matrix containing 10 wt.% octanoic acid and 30 wt.% water, which gave a tensile strength and Young's modulus of 18.7 MPa and 4 GPa, respectively. Hybrid matrix composites were compounded with a maleated polypropylene coupling agent and benzoyl peroxide as a cross-linking agent. The highest tensile strength and Young's modulus obtained from hybrid matrix composites were 36.9 MPa and 5.8 GPa with 50 wt.% fibre.

  19. Conduction noise absorption by fiber-reinforced epoxy composites with carbon nanotubes

    International Nuclear Information System (INIS)

    Lee, Ok Hyoung; Kim, Sung-Soo; Lim, Yun-Soo

    2011-01-01

    Nearly all electronic equipment is susceptible to malfunction as a result of electromagnetic interference. In this study, glass fiber, and carbon fiber as a type reinforcement and epoxy as a matrix material were used to fabricate composite materials. In an attempt to increase the conduction noise absorption, carbon nanotubes were grown on the surface of glass fibers and carbon fibers. A microstrip line with characteristic impedance of 50 Ω in connection with network analyzer was used to measure the conduction noise absorption. In comparing a glass fiber/epoxy composite with a GF-CNT/Ep composite, it was demonstrated that the CNTs significantly influence the noise absorption property mainly due to increase in electric conductivity. In the carbon fiber composites, however, the effectiveness of CNTs on the degree of electric conductivity is negligible, resulting in a small change in reflection and transmission of an electromagnetic wave. - Research Highlights: → In this study, glass fiber and carbon fiber as a type reinforcement and epoxy as a matrix material were used to fabricate composite materials. In an attempt to increase the conduction noise absorption, carbon nanotubes (CNTs) were grown on the surface of glass fibers and carbon fibers. A microstrip line with characteristic impedance of 50 Ω in connection with network analyzer was used to measure the conduction noise absorption. → In comparing a glass fiber/epoxy composite with a GF-CNT/Ep composite, it was demonstrated that the CNTs significantly influence the noise absorption property mainly due to increase in electric conductivity. In the carbon fiber composites, however, the effectiveness of CNTs on the degree of electric conductivity is negligible, resulting in a small change in reflection and transmission of an electromagnetic wave.

  20. The study of mechanical properties of pineapple leaf fibre reinforced tapioca based bioplastic resin composite

    Directory of Open Access Journals (Sweden)

    Mathivanan D.

    2016-01-01

    Full Text Available Natural fibre reinforced composite has brought the material engineering to a high new level of research. Natural fibres are compatible with matrices like polypropylene and can be used as reinforcement material to reduce the composition of plastic in a material. Natural fibres such as kenaf, pineapple leaf, and coir already found its importance in reducing the dependence of petroleum based products. However the biodegradability of the product at the end of the intended lifespan is still questionable. This has led many researches to look for a suitable replacement for synthetic fibres and achieve better adhesion between fibre and matrix. In this study, fiber and matrix which are hydrophilic in nature was used and the mixture was extruded and hot compressed to acquire better mechanical properties. The specimens were fabricated and tested according to ASTM D638. The 30% composition illustrates the best average modulus value among other composition and from this result it can be concluded that the increase of PALF fibre in TBR composite increases the modulus strength of the composite.

  1. Ballistic impact velocity response of carbon fibre reinforced aluminium alloy laminates for aero-engine

    Science.gov (United States)

    Mohammed, I.; Abu Talib, A. R.; Sultan, M. T. H.; Saadon, S.

    2017-12-01

    Aerospace and other industries use fibre metal laminate composites extensively due to their high specific strength, stiffness and fire resistance, in addition to their capability to be tailored into different forms for specific purposes. The behaviours of such composites under impact loading is another factor to be considered due to the impacts that occur in take-off, landing, during maintenance and operations. The aim of the study is to determine the specific perforation energy and impact strength of the fibre metal laminates of different layering pattern of carbon fibre reinforced aluminium alloy and hybrid laminate composites of carbon fibre and natural fibres (kenaf and flax). The composites are fabricated using the hand lay-up method in a mould with high bonding polymer matrix and compressed by a compression machine, cured at room temperature for one day and post cure in an oven for three hours. The impact tests are conducted using a gun tunnel system with a flat cylindrical bullet fired using a helium gas at a distance of 14 inches to the target. Impact and residual velocity of the projectile are recorded by high speed video camera. Specific perforation energy of carbon fibre reinforced aluminium alloy (CF+AA) for both before and after fire test are higher than the specific perforation energy of the other composites considered before and after fire test respectively. CF +AA before fire test is 55.18% greater than after. The same thing applies to impact strength of the composites where CF +AA before the fire test has the highest percentage of 11.7%, 50.0% and 32.98% as respectively compared to carbon fibre reinforced aluminium alloy (CARALL), carbon fibre reinforced flax aluminium alloy (CAFRALL) and carbon fibre reinforced kenaf aluminium alloy (CAKRALL), and likewise for the composites after fire test. The considered composites in this test can be used in the designated fire zone of an aircraft engine to protect external debris from penetrating the engine

  2. Morphological and mechanical analyses of laminates manufactured from randomly positioned carbon fibre/epoxy resin prepreg scraps

    Science.gov (United States)

    Souza, Christiane S. R.; Cândido, Geraldo M.; Alves, Wellington; Marlet, José Maria F.; Rezende, Mirabel C.

    2017-10-01

    This study aims to contribute to sustainability by proposing the reuse of composite prepreg scrap as an added value from discards. The research evaluates the microstructure and mechanical properties of laminates processed by the reuse of uncured carbon fibre/F155-epoxy resin prepreg scraps, waste from the ply cutting area of an aeronautical industry. The composite scraps were used as collected and were randomly positioned to produce laminates to be cured at an autoclave. The mechanical characterization shows a decrease of 39% for the compression property due to the discontinuous fibres in the laminate and an increase of 34% for the interlaminar shear strength, when compared to continuous fibre laminates. This increase is attributed to the higher crosslink density of the epoxy resin, as a result of the cure temperature used in autoclave (60 °C higher than suggested by supplier) and also to the randomly positioned scraps. Microscopic analyses confirm the consolidation of laminates, although show resin rich areas with different sizes and shapes attributed to the overlapping of the scraps with different sizes and shapes. These resin rich areas may contribute to decrease the mechanical properties of laminates. The correlation between mechanical and morphological results shows potential to be used on non-critical structural application, as composite jigs, contributing to sustainability.

  3. Modelling the post-cracking behaviour of steel fibre reinforced concrete for structural design purposes

    NARCIS (Netherlands)

    Kooiman, A.G.; Walraven, C.

    2000-01-01

    With the increasing number of applications in practice, the demand for standardised test methods and design rules for Steel Fibre Reinforced Concrete (SFRC) arises. Test methods need to be practical, which means that they have to be relatively cheap and simple to carry out. Design models should be

  4. 50-Hz plasma treatment of glass fibre reinforced polyester at atmospheric pressure enhanced by ultrasonic irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Norrman, Kion; Singh, Shailendra Vikram

    2011-01-01

    Glass fibre reinforced polyester (GFRP) plates are treated using a 50-Hz dielectric barrier discharge at peak-to-peak voltage of 30 kV in helium at atmospheric pressure with and without ultrasonic irradiation to study adhesion improvement. The ultrasonic waves at the fundamental frequency of around...

  5. Modelling the behaviour of steel fibre reinforced precast beam-to-column connection

    Science.gov (United States)

    Chai, C. E.; Sarbini, NN; Ibrahim, I. S.; Ma, C. K.; Tajol Anuar, M. Z.

    2017-11-01

    The numerical behaviour of steel fibre reinforced concrete (SFRC) corbels reinforced with different fibre volume ratio subjected to vertical incremental load is presented in this paper. Precast concrete structures had become popular in the construction field, which offer a faster, neater, safer, easier and cheaper construction work. The construction components are prefabricated in controlled environment under strict supervision before being erected on site. However, precast beam-column connections are prone to failure due to the brittle properties of concrete. Finite element analysis (FEA) is adopted due to the nonlinear behaviour of concrete and SFRC. The key objective of this research is to develop a reliable nonlinear FEA model to represent the behaviour of reinforced concrete corbel. The developed model is validated with experimental data from previous researches. Then, the validated FEA model is used to predict the behaviour of SFRC corbel reinforced with different fibre volume ratio by changing the material parameters. The results show that the addition of steel fibre (SF) increases the load carrying capacity, ductility, stiffness, and changed the failure mode of corbel from brittle bending-shear to flexural ductile. On the other hand, the increasing of SF volume ratio also leads to increased load carrying capacity, ductility, and stiffness of corbel.

  6. Asset management business model for design, realization, and maintenance of fibre reinforced polymer bridges

    NARCIS (Netherlands)

    Sebastian, R.

    2013-01-01

    This paper particularly addresses the market implementation of Fibre Reinforced Polymer (FRP) for bridges. It presents the concept of demand and supply chain innovation as being investigated within two ongoing European collaborative research projects (FP7) titled Trans-IND and PANTURA. FRP has

  7. Static And Dynamic Characteristics Of Waste Ceramic Aggregate Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Cichocki Krzysztof

    2015-12-01

    Full Text Available There are multiple obstacles associated both with technology and properties of waste ceramic aggregate concrete preventing its wide production and application. In the research programme these limitations were addressed through utilizing steel fibre reinforcement and the phenomenon of internal curing. After laboratory tests of mechanical properties a numerical analysis of composites in question was conducted.

  8. Numerical analyses of interaction of steel-fibre reinforced concrete slab model with subsoil

    Directory of Open Access Journals (Sweden)

    Jana Labudkova

    2017-01-01

    Full Text Available Numerical analyses of contact task were made with FEM. The test sample for the task was a steel-fibre reinforced concrete foundation slab model loaded during experimental loading test. Application of inhomogeneous half-space was used in FEM analyses. Results of FEM analyses were also confronted with the values measured during the experiment.

  9. Dual energy CT inspection of a carbon fibre reinforced plastic composite combined with metal components

    Czech Academy of Sciences Publication Activity Database

    Vavřík, Daniel; Jakůbek, J.; Kumpová, Ivana; Pichotka, M.

    6, Part B, November (2016), s. 47-55 ISSN 2214-6571 R&D Projects: GA MŠk(CZ) LO1219; GA ČR(CZ) GA15-07210S Keywords : dual energy computed tomography * carbon fibre reinforced plastic composite * metal artefact suppression Subject RIV: JI - Composite Material s http://www.sciencedirect.com/science/article/pii/S2214657116300107

  10. Fracture resistance of reattached incisor fragments with mini fibre-reinforced composite anchors.

    NARCIS (Netherlands)

    Fennis, W.M.M.; Kreulen, C.M.; Wolke, J.G.C.; Fokkinga, W.A.; Machado, C.; Creugers, N.H.J.

    2009-01-01

    OBJECTIVES: Fractured coronal fragments of incisors can be adhered to the remaining tooth with resin composite, but are prone to failure. This study explores whether mini fibre-reinforced composite (FRC) anchors increase fracture resistance of reattached fragments. METHODS: Forty-five extracted

  11. Mechanical spectroscopy of thermal stress relaxation in aluminium alloys reinforced with short alumina fibres

    Energy Technology Data Exchange (ETDEWEB)

    Carreno-Morelli, E.; Schaller, R. [Ecole Polytechnique Federale, Lausanne (Switzerland). Inst. de Genie Atomique; Urreta, S.E.

    1998-05-01

    The mechanical behaviour under low temperature thermal cycling of aluminium-based composites reinforced with short Al{sub 2}O{sub 3} SAFFIL fibres has been investigated by mechanical spectroscopy (mechanical loss and elastic shear modulus measurements). A mechanical loss maximum has been observed during cooling which originates in the relaxation of thermal stresses at the interfaces due to the differential thermal expansion between matrix and reinforcement. The maximum height increases with the volumetric fibre content. In addition, if the matrix strength is increased by the appropriated choice of alloy and thermal treatment, the maximum diminishes and shifts to lower temperatures. No damage accumulation at the interfaces has been detected during long period thermal cycling in the range 100 to 500 K. A description of the damping behaviour is made in terms of the development of microplastic zones which surround the fibres. (orig.) 9 refs.

  12. (nanoclay and CaSiO3)-reinforced E-glass-reinforced epoxy ...

    Indian Academy of Sciences (India)

    forming friction-reducing transfer films. Thus, the combined effects of strengthening and transfer film reduce the wear rate significantly. Wetzel et al [14] have studied the syner- gistic effects of micron-size CaSiO3 (4–15 μm) and nanosize. Al2O3 (13 nm) particles additions on mechanical and tribo- logical behaviour of epoxy ...

  13. Mechanical Behavior of Hybrid Glass/Steel Fiber Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    Amanda K. McBride

    2017-04-01

    Full Text Available While conventional fiber-reinforced polymer composites offer high strength and stiffness, they lack ductility and the ability to absorb energy before failure. This work investigates hybrid fiber composites for structural applications comprised of polymer, steel fiber, and glass fibers to address this shortcoming. Varying volume fractions of thin, ductile steel fibers were introduced into glass fiber reinforced epoxy composites. Non-hybrid and hybrid composite specimens were prepared and subjected to monolithic and half-cyclic tensile testing to obtain stress-strain relationships, hysteresis behavior, and insight into failure mechanisms. Open-hole testing was used to assess the vulnerability of the composites to stress concentration. Incorporating steel fibers into glass/epoxy composites offered a significant improvement in energy absorption prior to failure and material re-centering capabilities. It was found that a lower percentage of steel fibers (8.2% in the hybrid composite outperformed those with higher percentages (15.7% and 22.8% in terms of energy absorption and re-centering, as the glass reinforcement distributed the plasticity over a larger area. A bilinear hysteresis model was developed to predict cyclic behavior of the hybrid composite.

  14. Surface waves in fibre-reinforced anisotropic elastic media

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    reinforced solid elastic media. First, the theory of general surface waves has been derived and applied to study the particular cases of surface waves –. Rayleigh, Love and Stoneley types. The wave velocity equations are found to.

  15. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics...... a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG) sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored...... instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model....

  16. DURABILITY PROPERTIES OF FIBRE-REINFORCED POND ASH-MODIFIED CONCRETE

    Directory of Open Access Journals (Sweden)

    A. SOFI

    2016-10-01

    Full Text Available This paper presents an experimental study on the durability properties of pond ash-modified concrete randomly reinforced with steel fibres. Durability properties such as drying shrinkage, water absorption, permeable voids and acid attack were studied. The specimens were cast with three different pond ash contents of 10%, 20% and 30% by weight of cement. Grooved type steel fibres were added as 0.5%, 1% and 2% by volume of concrete to all the specimens. The results obtained were compared with those obtained with the conventional concrete. Change in length was measured for time periods of 1 day, 7 days, 14 days, 28 days, 56 days, 90 days and 180 days. The results indicated that drying shrinkage decreased with increase in pond ash content and fibre content. A pond ash content of 30% yielded good values of water absorption and permeable voids. Acid attack studies revealed that weight loss significantly decreased with increasing pond ash content and fibre content.

  17. Experimental Studies on Punching Shear and Impact Resistance of Steel Fibre Reinforced Slag Based Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Srinivasan Karunanithi

    2017-01-01

    Full Text Available The study was focused on slag based geopolymer concrete with the addition of steel fibre. The slag based geopolymer concrete was under shear load and sudden impact load to determine its response. The punching shear represents the load dissipation of the material and the energy absorption capacity of the geopolymer concrete to impact load. The various percentage of steel fibre in the slag based geopolymer concrete was 0.5%, 1.0%, and 1.5%. Overall the dosage 0.5% of steel fibre reinforced slag based geopolymer shows better results with a punching shear of 224 kN and 1.0% of steel fibre incorporated geopolymer concrete had the better energy absorption capacity with 3774.40 N·m for first crack toughness and 4123.88 N·m for ultimate failure toughness.

  18. Numerical and Experimental Investigation of the Hydrostatic Performance of Fibre Reinforced Tubes

    Science.gov (United States)

    Pavlopoulou, S.; Roy, S. S.; Gautam, M.; Bradshaw, L.; Potluri, P.

    2017-04-01

    The increasing demands in subsea industry such as oil and gas, led to a rapidly growing need for the use of advanced, high performance, lightweight materials such as composite materials. E-glass fibre laminated pre-preg, filament wound and braided tubes were tested to destruction under hydrostatic external pressure in order to study their buckling and crushing behaviour. Different fibre architectures and wind angles were tested at a range of wall thicknesses highlighting the advantage that hoop reinforcement offers. The experimental results were compared with theoretical predictions obtained from classic laminate theory and finite element analysis (ABAQUS) based on the principal that the predominant failure mode was buckling. SEM analysis was further performed to investigate the resulting failure mechanisms, indicating that the failure mechanisms can be more complex with a variety of observed modes taking place such as fibre fracture, delamination and fibre-matrix interface failure.

  19. Properties of Recycled Aggregate Concrete Reinforced with Polypropylene Fibre

    Directory of Open Access Journals (Sweden)

    Wan Mohammad Wan Nur Syazwani

    2016-01-01

    Full Text Available This research work is aimed to investigate how the addition of various proportion of polypropylene fibre affects the mechanical strength and permeability characteristics of recycled aggregate concrete (RAC which has been produced with treated coarse recycled concrete aggregate (RCA. Further research on RAC properties and their applications is of great importance as the scarcity of virgin aggregate sources in close proximity to major urban centers is becoming a worldwide problem. In this study, the hardened RAC properties at the curing age of 7 and 28 days such as compressive strength, flexural strength, ultrasonic pulse velocity (UPV, water absorption and total porosity were evaluated and compare with control specimens. Experimental result indicates that although the inclusion of the treated coarse RCA can enhance the mechanical strength and permeability properties of RAC, Further modification by addition of polypropylene fibre can optimize the results.

  20. Bamboo Fibre Reinforced Cement Used as a Roofing Sheet | Alade ...

    African Journals Online (AJOL)

    ... bamboo fibre-roofing sheet could be used as a low cost roofing sheet. It is however imperative that the roofing system should be at slope of 45o – 60o to ensure speedy flow of water down the slope and also reduce the shock effect when a lateral load falls on it. Journal of Civil Engineering Research and Practice Vol.1(2)

  1. Fractography of Alumina Fibre Reinforced Ex-polysiloxane Matrix Composites

    Czech Academy of Sciences Publication Activity Database

    Rudnayová, E.; Glogar, Petr

    2002-01-01

    Roč. 223, - (2002), s. 119-124 ISSN 1013-9826. [Fractography of Advanced Ceramic s 2001. Stará Lesná, 13.05.2001-16.05.2001] R&D Projects: GA ČR GA104/00/1140; GA ČR GA106/99/0096 Institutional research plan: CEZ:AV0Z3046908 Keywords : alumina fibre * fibrous composite * fracture features Subject RIV: JI - Composite Materials Impact factor: 0.497, year: 2002

  2. Characterization of Fibre-Direction Dependent Damping of Glass-Fibre Composites at Low Temperatures and Low Frequencies

    DEFF Research Database (Denmark)

    Kliem, Mathias; Høgsberg, Jan Becker; Dannemann, Martin

    2016-01-01

    This paper deals with the characterization of the fibre-direction dependent damping capability of glass fibre reinforced plastics (GFRP) to be used in electrical power transmission pylons. A fibre-direction dependent damping analysis of unidirectional (UD) GFRP samples was carried out using...... a Dynamic Mechanical Analysis (DMA) for five different fibre orientations (0˚ | 30˚ | 45˚ | 60˚ and 90˚) and two different matrix systems (epoxy and a vinyl ester resin). Based on the dynamic characteristics the damping performance of the various composite materials was studied at three temperatures (-10˚C......, 0˚C and 10˚C) and three vibration frequencies (1 Hz, 10 Hz and 30 Hz). It was observed that the loss factor of Glass Fibre Reinforced Vinyl-Ester (GF-VE) was in general slightly higher compared to the Glass Fibre Reinforced Epoxy (GF-EP). The loss factor increased slightly with temperature, while...

  3. Performance of mechanical behavior of kenaf fibre reinforced foamed composite

    Science.gov (United States)

    Mahzabin, Mst. Sadia; Hock, Lim Jee; Kang, Lim Siong; Jarghouyeh, Ehsan Nikbakht

    2017-10-01

    This paper investigates the mechanical properties of lightweight foamed composite (LFC) with the inclusion of kenaf fibres and superplasticizer. NaOH treated kenaf fibre contents of 0.4%, 0.45% and 0.5% (by weight of cement) with 5cm length were used in composite. The density of 1000kg/m3 to 2000kg/m3 foamed concrete was used for all the tested specimens. The ratio of cement, sand and water used was 1:1.5:0.45. All the experiments were set up in accordance with International standard methods of testing. In reference to the results and discussion, the different percentages of fibre used were proven to have a lesser contribution towards compressive strength or might even have reduced the result. The results also showed that water absorption and density of the composite mortar increased as the volume of fiber increased from 0.4% to 0.5% However, a higher percentage of fiber inclusions had been recorded to have a positive contribution towards flexural and tensile splitting properties of composites.

  4. Behaviour of Steel Fibre Reinforced Rubberized Continuous Deep Beams

    Science.gov (United States)

    Sandeep, MS; Nagarajan, Praveen; Shashikala, A. P.

    2018-03-01

    Transfer girders and pier caps, which are in fact deep beams, are critical structural elements present in high-rise buildings and bridges respectively. During an earthquake, failure of lifeline structures like bridges and critical structural members like transfer girders will result in severe catastrophes. Ductility is the key factor that influences the resistance of any structural member against seismic action. Structural members cast using materials having higher ductility will possess higher seismic resistance. Previous research shows that concrete having rubber particles (rubcrete) possess better ductility and low density in comparison to ordinary concrete. The main hindrance to the use of rubcrete is the reduction in compressive and tensile strength of concrete due to the presence of rubber. If these undesirable properties of rubcrete can be controlled, a new cementitious composite with better ductility, seismic performance and economy can be developed. A combination of rubber particles and steel fibre has the potential to reduce the undesirable effect of rubcrete. In this paper, the effect of rubber particles and steel fibre in the behaviour of two-span continuous deep beams is studied experimentally. Based on the results, optimum proportions of steel fibre and rubber particles for getting good ductile behaviour with less reduction in collapse load is found out.

  5. Mechanical properties of unidirectional oil palm empty fruit bunch (OPEFB) fiber reinforced epoxy composite

    Science.gov (United States)

    Hassan, C. S.; Yeo, C. W.; Sahari, B.; Salit, M. S.; Aziz, N. Abdul

    2017-06-01

    Natural fibers have proven to be an excellent reinforcement material for various polymers. In this study, OPEFB fiber with unidirectional alignment was incorporated in epoxy and an investigation on tensile and flexural characteristics of the composite has been carried out. A fiber surface modification utilizing alkaline treatment with 1 sodium hydroxide solution was used in order to increase the fiber matrix bond in the composite. The investigation was carried out for 0°, 45° and 90° fiber orientation. Result showed that the higher the angle of the fiber orientation, the higher the tensile strength and flexural strength the composite will yield.

  6. Impacts of Temperature Disparity on Surface Modification of Short Jute Fiber-Reinforced Epoxy Composites

    Science.gov (United States)

    Basak, Reshmi; Choudhury, P. L.; Pandey, K. M.

    2017-08-01

    Chase for manufacturing composite materials without negotiating on the physio-mechanical performance has been prevailing since long. Short jute fiber-reinforced epoxy based composites are prepared and their mechanical properties have been analyzed. The fibers are peroxide-silane treated under varying conditions of temperature from low to high. Results display that the jute composites set at higher temperature values indicate higher values of mechanical properties compared to those synthesized under lower temperature range. The same can be cited for liquid retaining capacity.

  7. Mechanical and dielectric characterization of hemp fibre reinforced polypropylene (HFRPP by dry impregnation process

    Directory of Open Access Journals (Sweden)

    2010-03-01

    Full Text Available Natural fibres such as jute, coir, sisal, bamboo and pineapple are known to have high specific strength and can be effectively used in composites in various applications. The use of hemp fibres to reinforce the polymer aroused great interest and expectations amongst scientists and materials engineers. In this paper, composites with isotactic polypropylene (iPP matrix and hemp fibres were studied. These materials were manufactured via the patented FIBROLINE process based on the principle of the dry impregnation of a fibre assembly with a thermoplastic powder (iPP, using an alternating electric field. The aim of this paper is to show the influence of fibre/matrix interfaces on dielectric properties coupled with mechanical behaviours. Fibres or more probably the fibre/matrix interfaces allow the diffusion of electric charges and delocalise the polarisation energy. In this way, damages are limited during mechanical loading and the mechanical properties of the composites increase. The structure of composite samples was investigated by X-ray and FTIR analysis. The mechanical properties were analysed by quasistatic and dynamic tests. The dielectric investigations were carried out using the SEMME (Scanning Electron Microscope Mirror Effect method coupled with the measurement of the induced current (ICM.

  8. Effect of Red Mud and Copper Slag Particles on Physical and Mechanical Properties of Bamboo-Fiber-Reinforced Epoxy Composites

    OpenAIRE

    Sandhyarani Biswas; Amar Patnaik; Ritesh Kaundal

    2012-01-01

    In the present work, a series of bamboo-fiber-reinforced epoxy composites are fabricated by using red mud and copper slag particles as filler materials. A filler plays an important role in determining the properties and behavior of particulate composites. The effects of these two fillers on the mechanical properties of bamboo-epoxy composites are investigated. Comparative analysis shows that with the incorporation of these fillers, the tensile strength of the composites increases significantl...

  9. MECHANICAL AND THERMO–MECHANICAL PROPERTIES OF BI-DIRECTIONAL AND SHORT CARBON FIBER REINFORCED EPOXY COMPOSITES

    Directory of Open Access Journals (Sweden)

    G. AGARWAL

    2014-10-01

    Full Text Available This paper based on bidirectional and short carbon fiber reinforced epoxy composites reports the effect of fiber loading on physical, mechanical and thermo-mechanical properties respectively. The five different fiber loading, i.e., 10wt. %, 20wt. %, 30wt. %, 40wt. % and 50wt. % were taken for evaluating the above said properties. The physical and mechanical properties, i.e., hardness, tensile strength, flexural strength, inter-laminar shear strength and impact strength are determined to represent the behaviour of composite structures with that of fiber loading. Thermo-mechanical properties of the material are measured with the help of Dynamic Mechanical Analyser to measure the damping capacity of the material that is used to reduce the vibrations. The effect of storage modulus, loss modulus and tan delta with temperature are determined. Finally, Cole–Cole analysis is performed on both bidirectional and short carbon fiber reinforced epoxy composites to distinguish the material properties of either homogeneous or heterogeneous materials. The results show that with the increase in fiber loading the mechanical properties of bidirectional carbon fiber reinforced epoxy composites increases as compared to short carbon fiber reinforced epoxy composites except in case of hardness, short carbon fiber reinforced composites shows better results. Similarly, as far as Loss modulus, storage modulus is concerned bidirectional carbon fiber shows better damping behaviour than short carbon fiber reinforced composites.

  10. Analysis and modeling of delamination factor in drilling of woven kenaf fiber reinforced epoxy using Box Behnken experimental design

    Science.gov (United States)

    Suhaily, M.; Che Hassan, C. H.; Jaharah, A. G.; Afifah, M. A.; Nor Khairusshima, M. K.

    2018-01-01

    In this research study, it presents a comprehensive mathematical model for correlating the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates using the Box Behnken experimental design. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated HSS drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs.

  11. An Investigation of the Mechanical Properties of Sisal Fibre, Loofah ...

    African Journals Online (AJOL)

    The mechanical properties of sisal fibre, loofah matt, epoxy resin and their resulting composites were determined experimentally. The influence of volume fraction of the reinforcing fibres and matt on the mechanical properties of the composites was investigated. It was found that loofah matt reduces the mechanical ...

  12. Effect of aging PET fibre on the mechanical properties of PET fibre reinforced cement composite

    Czech Academy of Sciences Publication Activity Database

    Machovič, Vladimír; Andertová, J.; Kopecký, L.; Černý, Martin; Borecká, Lenka; Přibyl, Oldřich; Kolář, František; Svítilová, Jaroslava

    2008-01-01

    Roč. 52, č. 3 (2008), s. 172-182 ISSN 0862-5468 R&D Projects: GA ČR GA106/05/2618 Institutional research plan: CEZ:AV0Z30460519 Keywords : cement composite * PET fibre * aging Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.644, year: 2008 http://www.ceramics-silikaty.cz/

  13. Fibre reinforced self-compacting concrete flow simulations in comparison with l-box experiments using carbopol

    DEFF Research Database (Denmark)

    Svec, Oldrich; Skocek, Jan; Olesen, John Forbes

    conducted and analysed by means of digital image analysis. Orientation tensor fields coming from the digital image analysis were compared with the simulation to verify the ability of the model to properly represent the flow of the fibre reinforced self-compacting concrete.......An evolution of distribution and orientation of fibres in the fibre reinforced self-compacting concrete during the casting process is an important matter as the final orientation and distribution of fibres can significantly influence mechanical properties of the structural elements. A two...

  14. Characterisation of Microstructure of We43 Magnesium Matrix Composites Reinforced with Carbon Fibres

    Directory of Open Access Journals (Sweden)

    Gryc A.

    2016-06-01

    Full Text Available In the paper the microstructures of WE43 matrix composites reinforced with carbon fibres have been characterised. The influence of reinforcement type and T6 heat treatment (a solution treatment at 525°C for 8 h, a hot water quench and a subsequent ageing treatment at 250°C for 16 h on microstructure have been evaluated. The light microscope and scanning electron microscope investigations have been carried out. No significant differences in samples reinforced with non-coated textiles have been reported. The substantial changes in sample reinforced with nickel-coated textile have been observed. The segregation of alloying elements to the matrix-reinforcement layer has been identified. The T6 heat treatment caused the appearance of disperse precipitates of β phase, but the process cannot be considered as satisfactory (irregular distribution, low volume fraction, relatively large size.

  15. Synthesis, characterization and antibacterial activity of biodegradable starch/PVA composite films reinforced with cellulosic fibre.

    Science.gov (United States)

    Priya, Bhanu; Gupta, Vinod Kumar; Pathania, Deepak; Singha, Amar Singh

    2014-08-30

    Cellulosic fibres reinforced composite blend films of starch/poly(vinyl alcohol) (PVA) were prepared by using citric acid as plasticizer and glutaraldehyde as the cross-linker. The mechanical properties of cellulosic fibres reinforced composite blend were compared with starch/PVA crossed linked blend films. The increase in the tensile strength, elongation percentage, degree of swelling and biodegradability of blend films was evaluated as compared to starch/PVA crosslinked blend films. The value of different evaluated parameters such as citric acid, glutaraldehyde and reinforced fibre to starch/PVA (5:5) was found to be 25 wt.%, 0.100 wt.% and 20 wt.%, respectively. The blend films were characterized using Fourier transform-infrared spectrophotometry (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA/DTA/DTG). Scanning electron microscopy illustrated a good adhesion between starch/PVA blend and fibres. The blend films were also explored for antimicrobial activities against pathogenic bacteria like Staphylococcus aureus and Escherichia coli. The results confirmed that the blended films may be used as exceptional material for food packaging. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Surface waves in fibre-reinforced anisotropic elastic media

    Indian Academy of Sciences (India)

    reinforced solid elastic media. First, the theory of general surface waves has been derived and applied to study the particular cases of surface waves – Rayleigh, Love and Stoneley types. The wave velocity equations are found to be in agreement with ...

  17. Tribo-performance of epoxy hybrid composites reinforced with carbon fibers and potassium titanate whiskers

    Science.gov (United States)

    Suresha, B.; Harshavardhan, B.; Ravishankar, R.

    2018-04-01

    The present investigation deals with the fabrication and characterization of epoxy reinforced with bidirectional carbon fiber mat (CF/Ep) and filled with 2.5, 5 and 7.5 wt% potassium titanate whiskers (PTw) composites. The effect of PTw loading on hardness, tensile properties and dry sliding wear behaviour of CF/Ep composite were carefully investigated in expectation of providing valuable information for the application of hybrid CF/Ep composites. Results indicated that the incorporation of PTw actually improved the hardness, tensile strength and tensile modulus of CF/Ep composites. Meanwhile, the specific wear rate of CF/Ep filled by 5 wt % PTw reached to 6.3× 10-14 m3/N-m, which is 41% lower than that of CF/Ep composite at the same dry sliding condition. It also seen that the fiber and filler worked synergistically to enhance the wear resistance. Further, for all composites the friction coefficient increases with increase in load and sliding velocity. However, PTw reinforced CF/Ep exhibited considerably higher coefficient of friction compared to unfilled ones, while PTw filler loading of 5 wt% was effective in reducing the specific wear rate of CF/Ep composite. The carbon fiber carried the applied load between the contact surfaces and protected the epoxy from severe abrasion of the counterface. At the same time, the exposed PTw out of the epoxy matrix around the fiber inhibited the direct scraping between the fiber and counterface so that the fibers could be less directly impacted during the subsequent wear process and they were protected from severe damage.

  18. Carbon nanofiber reinforced epoxy matrix composites and syntactic foams - mechanical, thermal, and electrical properties

    Science.gov (United States)

    Poveda, Ronald Leonel

    The tailorability of composite materials is crucial for use in a wide array of real-world applications, which range from heat-sensitive computer components to fuselage reinforcement on commercial aircraft. The mechanical, electrical, and thermal properties of composites are highly dependent on their material composition, method of fabrication, inclusion orientation, and constituent percentages. The focus of this work is to explore carbon nanofibers (CNFs) as potential nanoscale reinforcement for hollow particle filled polymer composites referred to as syntactic foams. In the present study, polymer composites with high weight fractions of CNFs, ranging from 1-10 wt.%, are used for quasi-static and high strain rate compression analysis, as well as for evaluation and characterization of thermal and electrical properties. It is shown that during compressive characterization of vapor grown carbon nanofiber (CNF)/epoxy composites in the strain rate range of 10-4-2800 s-1, a difference in the fiber failure mechanism is identified based on the strain rate. Results from compression analyses show that the addition of fractions of CNFs and glass microballoons varies the compressive strength and elastic modulus of epoxy composites by as much as 53.6% and 39.9%. The compressive strength and modulus of the syntactic foams is also shown to generally increase by a factor of 3.41 and 2.96, respectively, with increasing strain rate when quasi-static and high strain rate testing data are compared, proving strain rate sensitivity of these reinforced composites. Exposure to moisture over a 6 month period of time is found to reduce the quasi-static and high strain rate strength and modulus, with a maximum of 7% weight gain with select grades of CNF/syntactic foam. The degradation of glass microballoons due to dealkalization is found to be the primary mechanism for reduced mechanical properties, as well as moisture diffusion and weight gain. In terms of thermal analysis results, the

  19. Experimentation and numerical simulation of steel fibre reinforced concrete pipes

    Directory of Open Access Journals (Sweden)

    de la Fuente, Albert

    2011-06-01

    Full Text Available The results concerning on an experimental and a numerical study related to SFRCP are presented. Eighteen pipes with an internal diameter of 600 mm and fibre dosages of 10, 20 and 40 kg/m3 were manufactured and tested. Some technological aspects were concluded. Likewise, a numerical parameterized model was implemented. With this model, the simulation of the resistant behaviour of SFRCP can be performed. In this sense, the results experimentally obtained were contrasted with those suggested by means MAP reaching very satisfactory correlations. Taking it into account, it could be said that the numerical model is a useful tool for the optimal design of the SFRCP fibre dosages, avoiding the need of the systematic employment of the test as an indirect design method. Consequently, the use of this model would reduce the overall cost of the pipes and would give fibres a boost as a solution for this structural typology.

    En este artículo se presentan los resultados principales de un estudio experimental y numérico del comportamiento de tubos hormigón reforzado con fibras de acero (THFA. Se fabricaron y ensayaron 18 tubos de 600 mm de diámetro con cuantías de 10, 20 y 40 kg/m3 de fibras, concluyéndose varios aspectos tecnológicos relacionados con la fabricación y el ensayo así como del comportamiento resistente. Por otra parte, se ha desarrollado el modelo numérico MAP que permite la simulación del comportamiento resistente de THFA sometidos al ensayo de aplastamiento. Los resultados han sido satisfactorios para cualquier régimen de carga, permitiendo concluir que el modelo es una herramienta útil para el diseño óptimo de este tipo de tubos. Se concluye que el uso del modelo conduce a una reducción del coste del armado y da un impulso al uso de fibras como elemento de refuerzo en esta tipología estructural.

  20. Embedded Fibre Bragg Grating Sensor Response Model: Crack Growing Detection in Fibre Reinforced Plastic Materials

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to simulate the sensor output response of a Fibre Bragg Grating (FBG) sensor when embedded in a host material (Composite material or adhesive), during a crack growing/damage event. A finite element model of the crack growth mechanisms was developed...... the applicability of this technique to more complicated structures, and to be used as a structural health monitoring design tool....

  1. Mechanical and electrical properties of spandex reinforced GMWNT/epoxy shape memory composites

    Science.gov (United States)

    Sun, Jian; Xu, Yanyi; Chen, Yijin; Liu, Yanju; Leng, Jinsong

    2012-04-01

    In this presented paper, spandex fibers with high elasticity and high recovery ratio were added into shape memory epoxy resin, and the mechanical properties were improved obviously compared with pure shape memory resin. Compared with pure material, elastic modulus of the sample with 20vol% spandex was increased by 28.2%, tensile stress by 49.7%, and fracture strain by 16.4%. Then graphitized multi-walled carbon nanotubes (GMWNTs) were mixed into the spandex reinforced SMPCs to make it conductive. It was found that surface-modified (by acid treatment) GMWNTs incorporated very well with resin, and dispersion was achieved by high-energy sonication. In order to study the electrical conductivity, the Four-point Probe Method was conducted on the surface-modified GMWTs reinforced composites. ( an order of 6.86 x104 Ω •cm was obtained in samples with 4.5wt% modified-GMWNTs). In comparison with the pure spandex reinforced SMPCs, the elastic modulus of the surface-modified GMWTs (4.5wt%) reinforced composites was increased by 300%, the tensile stress by 26%. However, the elongation at break of the SMPCs was decreased when GWMNTs were mixed in it.

  2. Synthesis of carbon fibre-reinforced, silicon carbide composites by ...

    Indian Academy of Sciences (India)

    The aim of the present work centers on synthesizing and characterizing carbon fibre (Cf) reinforced, silicon carbide matrix composites which are considered to have potential applications in aerospace and automobile industry. A series of composites, namely the Cf-SiC, Cf-(SiC+ZrC), Cf-(SiC+ZrB2), and Cf-(SiC+ZrO2), have ...

  3. Effect of Coconut Fillers on Hybrid Coconut Kevlar Fiber Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    S. P. Jani

    2015-12-01

    Full Text Available This project focuses on the conversion of naturally available coconut fibers and shells into a useful composite. In addition to it, some mechanical properties of the resultant composite is determined and also the effect of coconut shell fillers on the composite is also investigated. The few portion of the composite is incorporated with synthetic Kevlar fiber, thus the coconut fiber is hybridized to enhance the mechanical properties of coconut. In this work two types of composite is fabricate, kevelar coconut fibre (kc composite and kevelarcoco nut fibre coconut shell filler (kccsf composite. Coconut fibers have low weight and considerable properties among the natural fibers, while coconut fillers have a good ductile and impact property. The natural fibers and fillers are treated with Na-OH to make it free of organic impurities. Epoxy resin is used as the polymer matrix. Two composite are produced one with fillers and the other without the fillers using compression molding method. Mechanical properties like tensile strength, flexural strength and water absorption tests are done with ASTM standard. It is observed that that the addition of filler materials improves the adhesiveness of the fibers leading to the increase in the above mentioned properties. The density of the composite is also low hence the strength to weight ratio is very high. The water absorption test also showed that the resultant composite had a small adhesion to water and absorption of water.

  4. Toughening of carbon fiber-reinforced epoxy polymer composites via copolymers and graphene nano-platelets

    Science.gov (United States)

    Downey, Markus A.

    Carbon fiber-reinforced epoxy composites currently play a significant role in many different industries. Due to their high cross-link density, aromatic epoxy polymers used as the matrix in composite materials are very strong and stiff however they lack toughness. This dissertation investigates three areas of the carbon fiber-reinforced composite, which have the potential to increase toughness: the carbon fiber surface; the fiber/matrix interphase; and the matrix material. Approaches to improving each area are presented which lead to enhancing the overall composite toughness without reducing other composite mechanical properties. The toughening of the base matrix material, DGEBA/mPDA, was accomplished by two methods: first, using low concentrations of aliphatic copolymers to enhance energy absorption and second by adding graphene nano-platelets (GnP) to act as crack deflection agents. 1wt% copolymer concentration was determined to substantially increase the notched Izod impact strength without reducing other static-mechanical properties. Toughening of DGEBA/mPDA using 3wt% GnP was found to be dependent on the aspect ratio of GnP and treatment of GnP with tetraethylenepentamine (TEPA). GnP C750 enhanced flexural properties but not fracture toughness because the small aspect ratio cannot effectively deflect cracks. TEPA-grafting enhanced GnP/matrix bonding. Larger aspect ratio GnP M5 and M25 showed significant increases in fracture toughness due to better crack deflection but also decreased flexural strength based on limited GnP/matrix bonding. TEPA-grafting mitigated some of the flexural strength reductions for GnP M5, due to enhanced GnP/matrix adhesion. In the high-fiber volume fraction composite, the fiber/matrix bonding was enhanced with UV-ozone surface treatment by reducing a weak fiber surface boundary layer and increasing the concentration of reactive oxygen groups on the fiber surface. Further increases in Mode I fracture toughness were seen with the

  5. Finite element investigations on the microstructure of fibre-reinforced composites

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available The effect of residual stress due to the curing process on damage evolution in unidirectional (UD fibre-reinforced polymer-matrix composites under longitudinal and transverse loading has been investigated using a three-dimensional micromechanical representative volume element (RVE model with a hexagonal packing geometry and the finite element method. Residual stress has been determined by considering two contributions: volume shrinkage of matrix resin from the crosslink polymerization during isothermal curing and thermal contraction of both resin and fibre as a result of cooling from the curing temperature to room temperature. To examine the effect of residual stress on failure, a study based on different failure criteria and a stiffness degradation technique has been used for damage analysis of the RVE subjected to mechanical loading after curing for a range of fibre volume fractions. Predicted damage initiation and evolution are clearly influenced by the presence of residual stress.

  6. Electron beam processing of carbon fibre reinforced braided composites beams

    International Nuclear Information System (INIS)

    Halasz, L.; Zsigmond, B.; Czvikovszky, T.

    2002-01-01

    Complete text of publication follows. In this paper the possibility of producing a new type carbon fiber reinforced composite is examined by applying braiding, a well-known process of textile technology. The appearance of the new Hungarian carbon fiber with excellent mechanical properties in the market enables the development of newer type carbon fiber reinforced composites in the continuously widening range of engineering applications. Advanced hollow profiles, pipes and other composite products can be manufactured in continuous operation. A new way of composite production of this kind is the manufacturing of reinforcing structure by braiding technology producing a composite with sufficient mechanical properties from this cross directional fabric-like textile structure by impregnation. This manufacturing process can complete the variety of hollow products serving the same purpose as pultrusion or filament winding. This way a profile type framework element with a hollow cross section is manufactured having favorable mechanical properties. Owing to its small mass and high specific strength this product can be applied in dynamically loaded structures e.g. in the automotive industry. For crosslinking of the matrix the method of high-speed electron beam curing has been examined in order to reach continuous operation. The field of use and application of carbon fiber braided structures has a great chance especially in machine engineering and in the automotive industry. The main reason for this is that braiding processes are capable of producing structures having good mechanical properties at a low processing price. The mass of the composite load-bearing structure produced this way is one fifth of the steel product having similar geometry, and its specific mechanical properties are nearly as good as that of the most commonly applied semiproduct and structural component, the welded steel profile

  7. Effect of Mesh Distribution on Impact Resistance Performance of Kenaf Fibre Reinforced Concrete

    Science.gov (United States)

    Che Muda, Zakaria; Thiruchelvam, Sivadass; Syamsir, Agusril; Sheng, Chiam Yung; Beddu, Salmia; Nasharuddin Mustapha, Kamal; Usman, Fathoni; Liyana Mohd Kamal, Nur; Ashraful Alam, Md; Birima, Ahmed H.; Zaroog, O. S.

    2016-03-01

    This paper investigate the effect of the mesh distribution on the impact performance of kenaf fibre mesh reinforced concrete (KFMRC) for the concrete slab of 300mm × 300mm size reinforced with varied thickness and mesh diameter subjected to low impact projectile test. A self-fabricated drop-weight impact test rig with a steel ball weight of 1.236 kg drop at 0.40 m height has been used in this research work. The objective of this research is to study the effect of the mesh distribution on the impact resistance kenaf fibre mesh concrete for various slab thickness and mesh diameter. 2-layers one Top and one Bottom mesh distribution kenaf mesh is the most efficient in the ability to control crack formation and propagation against impact energy followed by 1-layer Middle mesh distribution and lastly the 1-layer Top mesh distribution is the least effective.

  8. Performance of kevlar fibre-reinforced rubber composite armour against shaped-charge jet penetration

    Directory of Open Access Journals (Sweden)

    Xu-dong Zu

    Full Text Available AbstractThe protective capability of the Kevlar fibre-reinforced rubber composite armour (KFRRCA at different obliquities is studied using depth-of-penetration experiments method against a 56 mm-diameter standard-shaped charge. Efficiency factors are calculated to evaluate the protection capability of the KFRRCA at different obliquities. Meanwhile, an X-ray experiment is used to observe the deformation, fracture, and scatter of the shaped-charge jet as it penetrates the composite armour. Finally, scanning electron microscopy (SEM is used to analyse the effect of the Kevlar fibre-reinforced rubber for the composite armour to resist jet penetration. The results showed that the KFEECA can be used as additional armour, because it has excellent protection capability, and it can disturb the stability of the middle part of the shaped charge jet (SCJ obviously especially when the armour at 30°and 68° obliquities.

  9. Residual characteristic properties of ternary blended steel fibre reinforced concrete subjected to sustained elevated temperature

    Directory of Open Access Journals (Sweden)

    Sinha Deepa A.

    2013-09-01

    Full Text Available To study the behavior of ternary blended steel fibre reinforced concrete when subjected to 800 Deg.C and 1000 Deg.C for 3 hours. It has been found that the ternary blended steel fibre reinforced concrete containing (FA+GGBFS and (FA+MK offer higher resistance to sustained elevated temperatures upto 800 Deg.C, where as the blend containing (FA+SF does not offer any resistance at this temperature. The study reveals that the blend containing (FA+GGBFS and (FA+MK gives highest resistance at replacement levels of (10+20 and (15+15 respectively at sustained exposure to 800 Deg.C.

  10. Cost efficient carbon fibre reinforced thermoplastics with in-situ polymerization of polyamide

    Science.gov (United States)

    Köhler, T.; Akdere, M.; Röding, T.; Gries, T.; Seide, G.

    2017-10-01

    Lightweight design has gained more and more relevance over the last decades. Especially in automotive industry it is of paramount importance to reduce weight and save fuel. At the same time the demand for safety and performance increases the components’ weight. To reach a trade-off between driving comfort and efficiency new lightweight materials have to be developed. One possible solution is the usage of carbon fibre reinforced thermoplastics (CFRTP) as a lightweight substitute material. In contrast to conventional carbon fibre reinforced plastics (CFRP), CFRTPs are cheaper and have a higher impact resistance. Furthermore they are characterized by hot forming ability, weldability and recyclability. However, the impregnation of the textile requires high pressure, because of the melted polymer’s high viscosity. A new innovative approach for CFRTP is the usage of in-situ polymerization with ɛ-caprolactam as matrix, which has a much lower viscosity and thus requires much lower pressure for impregnation and consolidation.

  11. Thermo-mechanical correlations to erosion performance of short carbon fibre reinforced vinyl ester resin composites

    International Nuclear Information System (INIS)

    Kumar, Sandeep; Satapathy, Bhabani K.; Patnaik, Amar

    2011-01-01

    Research highlights: → Composite with 30 wt.% of short carbon fibres exhibit highest energy dissipation. → Optimum erosion resistance conditions have been found. → A direct correlation emerged between erosive wear rate and loss-modulus inverse. → Mechanistic equivalence between erosion and dynamic loading modes is established. -- Abstract: Thermo-mechanical properties and erosion performance of short carbon fibre reinforced vinyl ester resin based isotropic polymer composites with four different fibre weight fractions have been investigated. The storage, loss and damping characteristics were analysed to assess the energy absorption/viscous recoverable energy dissipation and reinforcement efficiency of the composites as a function of fibre content in the temperature range of 0-140 o C. The composite with 30 wt.% of short carbon fibres has been observed to exhibit superior thermo-mechanical response with highest energy dissipation/damping ability accompanied with a constant storage modulus without any substantial decay till 60 o C. The erosion rates (Er) of these composites are evaluated at different impingement angles (30-90 o ), fibre loadings (20-50 wt.%), impact velocities (43-76 m/s), stand-off distances (55-85 mm) and erodent sizes (250-600 μm) following the erosion test schedule in an air jet type test rig. An optimal parameter combination is determined and subsequently validated for erosion rate minimization following Taguchi method and by conducting confirmation experiments. A correlation between the loss-modulus inverse and the erosion rate has been observed which conceptually establishes a possible mechanistic equivalence between erosion and dynamic mechanical loading modes. The morphologies of eroded surface are examined by the scanning electron microscopy to investigate the nature of wear-craters, material damage mode and other qualitative attributes responsible for promoting erosion.

  12. Static, Fire and Fatigue Tests of Ultra High-Strength Fibre Reinforced Concrete and Ribbed Bars

    DEFF Research Database (Denmark)

    Hansen, Lars Pilegaard; Heshe, Gert

    2001-01-01

    A new building system has been developed during the last 10 years. This new system consists of a column / slab system with 6 x 6 m distance between the columns. The slabs are precast concrete elements of size 2.9 x 5.9 m connected through joints of ultra high strength fibre reinforced concrete...... tests of tensile specimens consisting of reinforcing bars embedded in Densit Joint Cast ®. The objective of these fatigue tests is to show that the system / connection can presumably also be used in structures subjected to dominant time- varying loads and thus for example in earthquake regions....

  13. The effect of processing route and reinforcement geometry on isothermal creep behaviour of particulate and short fibre MMCs

    Energy Technology Data Exchange (ETDEWEB)

    Whitehouse, A.F. [Leicester Univ. (United Kingdom). Dept. of Engineering; Winand, H.M.A.; Clyne, T.W. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom)

    1998-02-01

    Isothermal creep tests were performed on discontinuously reinforced Al composites at 270 and 300 C. Axial and transverse strain were monitored simultaneously during testing using laser scanning extensometry. Damage mechanisms were found to dominate the creep behaviour rather than load transfer considerations. The effect of powder-processing versus squeeze infiltration on composite creep behaviour was characterised. The effect of interfacial bond strength was investigated by comparing carbon and Saffil (alumina) short fibre reinforcements. The effect of reinforcement shape, size and aspect ratio was also investigated by comparing short fibre, whisker and particulate reinforcements. (orig.) 27 refs.

  14. Designing of epoxy composites reinforced with carbon nanotubes grown carbon fiber fabric for improved electromagnetic interference shielding

    Directory of Open Access Journals (Sweden)

    B. P. Singh

    2012-06-01

    Full Text Available In this letter, we report preparation of strongly anchored multiwall carbon nanotubes (MWCNTs carbon fiber (CF fabric preforms. These preforms were reinforced in epoxy resin to make multi scale composites for microwave absorption in the X-band (8.2-12.4GHz. The incorporation of MWCNTs on the carbon fabric produced a significant enhancement in the electromagnetic interference shielding effectiveness (EMI-SE from −29.4 dB for CF/epoxy-composite to −51.1 dB for CF-MWCNT/epoxy multiscale composites of 2 mm thickness. In addition to enhanced EMI-SE, interlaminar shear strength improved from 23 MPa for CF/epoxy-composites to 50 MPa for multiscale composites indicating their usefulness for making structurally strong microwave shields.

  15. Performance of kevlar fibre-reinforced rubber composite armour against shaped-charge jet penetration

    OpenAIRE

    Zu,Xu-dong; Huang,Zheng-xiang; Zhai,Wen

    2015-01-01

    AbstractThe protective capability of the Kevlar fibre-reinforced rubber composite armour (KFRRCA) at different obliquities is studied using depth-of-penetration experiments method against a 56 mm-diameter standard-shaped charge. Efficiency factors are calculated to evaluate the protection capability of the KFRRCA at different obliquities. Meanwhile, an X-ray experiment is used to observe the deformation, fracture, and scatter of the shaped-charge jet as it penetrates the composite armour. Fin...

  16. FTIR and Thermal Studies on Nylon-66 and 30% Glass Fibre Reinforced Nylon-66

    OpenAIRE

    Charles, Julie; Ramkumaar, G. R.; Azhagiri, S.; Gunasekaran, S.

    2009-01-01

    The present study deals with the characterization of the polymeric materials viz., nylon-66 and 30% glass fibre reinforced nylon-66 (GF Nylon-66) by employing FTIR and thermal measurements. The complete vibrational band assignment made available for nylon-66 and GF nylon-66 using FTIR spectra confirm their chemical structure. FTIR spectroscopy provides detailed information on polymer structure through the characteristic vibrational energies of the various groups present in the molecule. The t...

  17. Behaviour of timber and steel fibre reinforced concrete composite constructions with screwed connections

    Czech Academy of Sciences Publication Activity Database

    Caldová, E.; Blesák, L.; Wald, F.; Kloiber, Michal; Urushadze, Shota; Vymlátil, P.

    2014-01-01

    Roč. 59, č. 4 (2014), s. 639-659 ISSN 1336-4561 R&D Projects: GA MŠk(CZ) LO1219; GA ČR(CZ) GAP105/10/2159 Keywords : timber * steel fibre reinforced concrete (SFRC) * screws * numerical model Subject RIV: JN - Civil Engineering Impact factor: 0.364, year: 2014 http://www.woodresearch.sk/articles.php?volume=12&issue=47

  18. Studies on mechanical, thermal and dynamic mechanical properties of untreated (raw) and treated coconut sheath fiber reinforced epoxy composites

    International Nuclear Information System (INIS)

    Suresh Kumar, S.M.; Duraibabu, D.; Subramanian, K.

    2014-01-01

    Highlights: • UTCSE and TCSE composites have been fabricated by compression molding technique. • The prepared specimens were characterized by FTIR, DMA, TGA and SEM techniques. • TCSE composite showed higher mechanical properties compared to UTCSE composite. • DMA showed that TCSE composite exhibited higher storage modulus than UTCSE composite. • TCSE composite showed higher thermal stability than UTCSE composite. - Abstract: The untreated (raw) coconut sheath fiber reinforced epoxy (UTCSE) composite and treated coconut sheath fiber reinforced epoxy (TCSE) composite have been fabricated using hand layup followed by compression molding technique. The prepared specimens were characterized by Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques. The prepared specimens are cut as per ASTM Standards to measure tensile, flexural and impact strengths by using universal testing machine and izod impact tester respectively. The treated coconut sheath fiber reinforced epoxy composite (TCSE) posses higher mechanical strength and thermal stability compared to untreated (raw) coconut sheath fiber reinforced epoxy composite (UTCSE). In the SEM fracture analysis, TCSE composite showed better fiber–matrix bonding and absence of voids compared to UTCSE composite

  19. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    International Nuclear Information System (INIS)

    Hopmann, Ch.; Kerschbaum, M.; Küsters, K.

    2014-01-01

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization

  20. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    Energy Technology Data Exchange (ETDEWEB)

    Hopmann, Ch., E-mail: kerschbaum@ikv.rwth-aachen.de; Kerschbaum, M., E-mail: kerschbaum@ikv.rwth-aachen.de; Küsters, K., E-mail: kerschbaum@ikv.rwth-aachen.de [Institute of Plastics Processing at RWTH Aachen University (IKV), Pontstrasse 49, 52064 Aachen (Germany)

    2014-05-15

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization.

  1. A Study on the Mechanical Properties of Oil Palm Mesocarp Fibre-Reinforced Thermoplastic

    Directory of Open Access Journals (Sweden)

    Olusola Femi Olusunmade

    2016-01-01

    Full Text Available Oil palm mesocarp fibre obtained from a palm oil processing mill was washed with detergent and water to remove the oil and sun-dried to enhance good adhesion to Linear Low Density Polyethylene (LLDPE. The fibre was pulverized and filtered through a sieve of pore size 300 microns. The Oil Palm Mesocarp Fibre Reinforced Thermoplastic (OPMFRT was produced with a form of hand lay-up method and varying fibres weight ratio in the matrix from 5 wt% to 25 wt% in steps of 5 wt%. Tensile test was carried out to determine the tensile strength, tensile modulus, and elongation at break of the material. The hardness and impact strength of the composite were also determined. The results showed that tensile modulus and hardness of the OPMFRT increased by 50% and 24.56%, respectively, while tensile strength, impact strength, and percentage elongation of the OPMFRT decreased by 36.78%, 39.07%, and 95.98%, respectively, as fibre loading increased from 5 wt% to 25 wt%. The study concluded that the application of the OPMFRT developed should be restricted to areas demanding high rigidity and wear resistance.

  2. A finite deformation continuum modelling framework for curvature effects in fibre-reinforced nanocomposites

    Science.gov (United States)

    Asmanoglo, Tobias; Menzel, Andreas

    2017-10-01

    Motivated by experimental findings on one-dimensional nano-materials, this contribution focusses on the elaboration of a fibre curvature based higher-order gradient contribution to the stored energy function in a finite deformation setting. The presented approach is based on the fundamental theoretical developments for fibre-reinforced composites presented by Spencer and Soldatos (2007), which take into account the fibre-bending stiffness in addition to the directional dependency induced by the fibres. A mixed-type finite element formulation is then used for the solution of the resulting system of coupled partial differential equations. A specific form of the stored energy function is introduced such that well-interpretable contributions to the stress- and the couple stress tensor are obtained. It is shown that this framework may, in principle, account for fibres of different diameters and induces a natural length scale into the model. Such continuum theory covering size-effects is of special interest since experiments for different materials suggest significant size-effects at small length scales.

  3. Mallow Fiber-Reinforced Epoxy Composites in Multilayered Armor for Personal Ballistic Protection

    Science.gov (United States)

    Nascimento, Lucio Fábio Cassiano; Louro, Luis Henrique Leme; Monteiro, Sergio Neves; Lima, Édio Pereira; da Luz, Fernanda Santos

    2017-10-01

    Lighter and less expensive polymer composites reinforced with natural fibers have been investigated as possible components of a multilayered armor system (MAS) for personal protection against high-velocity ammunition. Their ballistic performance was consistently found comparable with that of conventional Kevlar® synthetic aramid fiber. Among the numerous existing natural fibers with the potential for reinforcing polymer composites to replace Kevlar® in MAS, mallow fiber has not been fully investigated. Thus, the objective of this work is to evaluate the ballistic performance of epoxy composites reinforced with 30 vol.% of aligned mallow fibers as a second MAS layer backing a front ceramic plate. The results using high-velocity 7.62 ammunition show a similar indentation to a Kevlar® layer with the same thickness. An impedance matching calculation supports the similar ballistic performance of mallow fiber composite and Kevlar®. Reduced MAS costs associated with the mallow fiber composite are practical advantages over Kevlar®.

  4. The effects of stacking sequence and thermal cycling on the flexural properties of laminate composites of aluminium-epoxy/basalt-glass fibres

    Science.gov (United States)

    Abdollahi Azghan, Mehdi; Eslami-Farsani, Reza

    2018-02-01

    The current study aimed at investigating the effects of different stacking sequences and thermal cycling on the flexural properties of fibre metal laminates (FMLs). FMLs were composed of two aluminium alloy 2024-T3 sheets and epoxy polymer-matrix composites that have four layers of basalt and/or glass fibres with five different stacking sequences. For FML samples the thermal cycle time was about 6 min for temperature cycles from 25 °C to 115 °C. Flexural properties of samples evaluated after 55 thermal cycles and compared to non-exposed samples. Surface modification of aluminium performed by electrochemical treatment (anodizing) method and aluminium surfaces have been examined by scanning electron microscopy (SEM). Also, the flexural failure mechanisms investigated by the optical microscope study of fractured surfaces. SEM images indicated that the porosity of the aluminium surface increased after anodizing process. The findings of the present study showed that flexural modulus were maximum for basalt fibres based FML, minimum for glass fibres based FML while basalt/glass fibres based FML lies between them. Due to change in the failure mechanism of basalt/glass fibres based FMLs that have glass fibres at outer layer of the polymer composite, the flexural strength of this FML is lower than glass and basalt fibres based FML. After thermal cycling, due to the good thermal properties of basalt fibres, flexural properties of basalt fibres based FML structures decreased less than other composites.

  5. Study of wear mechanism of chopped fiber reinforced epoxy composite filled with graphite and bronze

    Science.gov (United States)

    Patil, Nitinchand; Prasad, Krishna

    2018-04-01

    The combined effect of graphite and sintered bronze with a short glass fiber reinforced epoxy composites was investigated in this work. A pin on disc wear test was carried out to study the wear behaviour and mechanism of the composites. The objective of this work is to develop an alternate friction resistance material for the application of sliding bearing. It was observed that the addition of sintered bronze improved mechanical and thermal stability of the composites as bronze has low contact resistance with graphite and has high thermal conductivity. It was observed from the test results that increased volume percentage of graphite and presence of bronze are play significant role in wear mechanism of the composites. It was observed from the scanning electronic microscopes (SEM) that the abrasive and adhesive wear mechanism was prominent in this study. It was also evident from the result that the frictional force remains stable irrespective of the applied normal load.

  6. Boron-epoxy-reinforced titanium aircraft landing-gear drag strut

    International Nuclear Information System (INIS)

    Howell, W.E.

    1976-11-01

    The structural performance of a boron-epoxy-reinforced titanium drag strut, containing a bonded scarf joint and designed to the criteria of a large commercial transport, has been evaluated experimentally and analytically. The strut was exposed to two lifetimes of fatigue loading and was statically loaded to the tensile and compressive design ultimate loads. Throughout the test program no evidence of any damage in the drag strut was detected by strain-gage measurements, ultrasonic inspection, or visual observation. The bonded joint was analyzed using the NASTRAN computer program. A comparison of the strains predicted by the NASTRAN computer program with the experimentally determined values shows excellent agreement. An analytical study indicated that the nonlinear behavior of a structural spacer at each end of the strut could be explained by the inelastic behavior and possible creep of the adhesive

  7. Characterization of Nylon 6 Nano Fiber/E-Glass Fiber Reinforced Epoxy Composites

    Science.gov (United States)

    Vinod Kumar, T.; Chandrasekaran, M.; Santhanam, V.; Udayakumar, N.

    2017-03-01

    In the paper thermoplastic polymer Nylon-6 is generated in the form of Nanofibers by using an electro spinning method, and concentration of a solution is 4% as a constant then, by varying the process parameters such as flow rate (0.8 ml/hr, 1ml/hr and 1.2 ml/hr) of the solution. The results indicated Nanofibers with 4% concentration and 1 ml/hr produced optimum fibers due to continuous fiber formation. Composites Plates are fabricated by using a Hand lay-up method with different volume fraction (0.5, 1, 2 % v/v) of Nanofibers ratio. Then, the optimum Nanofibers volume ratio (2 % v/v) is reinforced with E-glass fibers and epoxy resin as a matrix. In order to find Nanofibers effect, Mechanical properties like (Tensile, Flexural and Impact) is performed and evaluated.

  8. Pengaruh One Direction Pre-Tension pada Reinforcement Fibre terhadap Kekuatan Tarik dan Impact Fibre-Powder Reinforcement Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Gilang Gumilar

    2017-12-01

    Full Text Available Nowadays, industrial manufacturing needs environmentally and friendly material and has special properties which are difficult to obtain from the metal material. Composite is one of the alternative materials that can be used to meet those needs. A structural composite material consisting of a combination of two or more elements bonded material at the macroscopic level. This study was conducted to determine the effect of pre-tension one direction on a hybrid composite reinforcement against tensile strength and impact strength. Composite materials prepared by C-Glass fiber types woven rovings, coconut shell powder and vinyl ester resin. manufacturing composite using hand lay-up methods. The variation of the tension given 0N, 50N, 100N, 150N, and 200N. A tensile test based on the reference standard ASTM D 3039 while testing the impact based on ASTM D 6110-04. The results were obtained giving tension to the hybrid composite reinforcement increases tensile strength and impact strength of the material. The lowest tensile strength of the composite obtained in 0N treatment (without treatment ranged 71,58N / mm², and the greatest tensile strength is obtained in the pre-tension 200N, ranging from 106.05 N / mm2. As for the lowest impact on specimens obtained without treatment ranges 1,34J / mm2 and provision of pre-tension 200N biggest impact strength values obtained, ranging 15,09J / mm2.

  9. A novel zirconia fibre-reinforced resin composite for dental use.

    Science.gov (United States)

    Wang, Ting; Tsoi, James Kit-Hon; Matinlinna, Jukka Pekka

    2016-01-01

    The purpose of this study was to evaluate and compare some biomechanical properties such as fracture toughness, Vickers hardness and compressive strength of an experimental fibre-reinforced composite (FRC) filled with various percentages (0 wt%, 1 wt%, 3 wt%, and 5 wt%) of zirconia (ZrO2) fibres. A resin matrix (78.4 wt% bis-GMA, 19.6 wt% MMA, 1-wt% CEMA and 1 wt% CQ) with different percentages of silanized zirconia fibres (0%, 1%, 3%, and 5% by weight of the resin matrix) was prepared. Silanization was carried out using an experimental silane blend (0.5 vol% bis-1,2-(triethoxysilyl)ethane+1.0 vol% 3-acryloxypropyltrimethoxysilane in ethanol, at pH 4.0). Each group of specimens was stored in two conditions - either at room temperature for one day or water storage at 37 °C for 7 days. They were randomly divided into study groups according to the test method. For fracture toughness, a notchless triangular prism (NTP) test (n=6) was undertaken. Hardness values (n=6) were measured by using a Vickers hardness testing machine and compressive strength (n=6) was tested. Scanning electron microscopy (SEM) images were taken at the fracture sites after fracture toughness test. The data were analysed by 1-way ANOVA (analysis of variance) and Bonferroni post-hoc tests (α=0.05). The ANOVA test revealed that the experimental FRCs with 1 wt% and 3 wt% zirconia fibres showed statistically significant differences in Vickers hardness at dry condition and NTP fracture toughness after 7-day water storage, respectively. However, compressive strength of experimental groups exhibited no significant difference (p>0.05). Silanized zirconia fibres reinforcement in resin is a novel FRC which have shown promising biomechanical properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Strengthening of beam - column joint with steel fibre reinforced concrete under seismic loading

    Science.gov (United States)

    Prasanna, K.; Ramasubramani, R.; Anandh, K. S.; Saisabarish; Krupaker Maddu, Vijay

    2017-07-01

    Earthquakes not only kill the human beings but the structures too. Considering this above fact, there is a necessity to take care of the beam column joint region in a structure. Under seismic excitation, the bar segment joint district is subjected to even and the vertical shear force extents are normally commonly greater than those in the adjoining bits of the structural segments. In the event that the joint is not precisely nitty gritty, the shaft segment joint may end up plainly frail. To keep this, an adequate control ought to be given in the joint area. The seismic examination and outline technique ought to be utilised as a part of the plan of the building structures and their segments ought to be recommended in the segment. The building structures incorporate finish sidelong and vertical drive opposing frameworks fit for giving satisfactory quality. Stiffness and the vitality dissemination ability to withstand the outline ground movements inside the recommended furthest reaches of twisting and quality request. The plan ground movements are accepted to happen along any even headings of a building structure. This work focuses on behaviour of M20 concrete in beam-column joint subjected to seismic loading, by using steel fibre (1.5%). The specimens detailed as per IS: 456-2000 and IS: 13920-1993 were casted and tested under cyclic and reverse cyclic loading. The parameters analysed were ductility, energy dissipation, load v/s displacement curve, beam-column reinforcement strain and crack pattern. From the experimental investigation, it is found that the fibre reinforced beam-column joint with fibre (1.50% of steel fibre) performs better ductility, load carrying capacity, energy dissipation and strength by 10% more than conventional reinforced beam-column joint.

  11. Compressive Behaviour of RC Column with Fibre Reinforced Concrete Confined by CFRP Strips

    Directory of Open Access Journals (Sweden)

    A. M. Vasumathi

    2014-01-01

    Full Text Available The structural application of synthetic fibre reinforced concrete (FRC has become widespread in the construction industry in order to satisfy the requirement of the earthquake resistant structures. Research conducted so far are focused on the structural behaviour of RC column externally confined with FRP composites, while studies are needed to address the behaviour of FRP strengthened RC column fabricated using fibre reinforced concrete. With the intention that the experimental investigation was carried out to evaluate the feasibility use of CFRP composite strips in strengthening of RC column made with fibre reinforced concrete. Circular synthetic Polypropylene fibre was used in the rate of 0.50% in the volume of concrete. CFRP strips having a width of 50 mm were used to confine the column and the experimental parameters were effective spacing between the CFRP strips (20 mm and 30 mm and the number of CFRP layers (one, two and three. The externally bonded CFRP strips counteract the lateral expansion of the concrete significantly by providing restraining effect and thus effect enhanced the stiffness of the column. The column strengthened with CFRP strips showed a maximum of 198.87% and 91.75% enhancement in axial deformation control and ultimate strength, respectively, compared to that of reference column. From the test results obtained, it is suggested that CFRP strips with the spacing of 20 mm and 30 mm can be used in strengthening of RC column made with FRC; however the column confined with 30 mm spacing provides an economical advantage compared to that of 20 mm spacing.

  12. Multidimensional Nanocomposites of Epoxy Reinforced with 1D and 2D Carbon Nanostructures for Improve Fracture Resistance

    Directory of Open Access Journals (Sweden)

    Juventino López-Barroso

    2018-03-01

    Full Text Available A hybrid nanocomposites based on epoxy reinforced with a combination of 1D and 2D carbon nanomaterials for improving impact resistance are reported. Multi-walled carbon nanotubes and oxidized-multi-walled carbon nanotubes are used as 1D nanoreinforcements, and graphene derivative materials such as graphene oxide and reduced graphene oxide are utilized as 2D nanoreinforcements. In this research, the impact resistance of epoxy matrix reinforced with 1D or 2D and the mixture of both nanomaterials is studied. The research is focused on evaluation of the influence of adding different combinations of nanomaterials into epoxy resin and their Izod impact response. Moreover, fracture surface of nanocomposites is observed by scanning electron microscopy. Images show differences between the surfaces of brittle nature on thermoset epoxy polymer and tough nanocomposites. Synergy created with 1D and 2D nanomaterials produces stable dispersions in the processing, reflected in the interface. The interactions in nanocomposites are evidenced by infrared spectra, principally on the peaks related to oxygenated functional groups present in nanomaterials and absent in polymer matrix. Consequently, an increase of 138% in fracture strength of nanocomposites is exhibited, in comparison to the neat epoxy matrix. In addition, hybrid nanocomposites were synthesized in two different methods to evaluate the influence of manufacturing method on final properties of nanocomposites.

  13. The effect of particle addition and fibrous reinforcement on epoxy-matrix composites for severe sliding conditions

    DEFF Research Database (Denmark)

    Larsen, Thomas Ricco Ølholm; Løgstrup Andersen, Tom; Thorning, Bent

    2008-01-01

    . The purpose is to systematically compare the performance of the differently reinforced materials while going from mild to severe sliding conditions. It is found that the coefficient of friction (mu) on average is reduced by 35% by substituting the glass fiber weave with the carbon/aramid weave. The latter...... pv conditions all tested composites show signs of decomposition. Despite this, glass fiber reinforcement has a relatively steady behavior while carbon/aramid reinforcement gives raise to a gradually increasing frictional force, which ultimately results in complete failure of the test-specimen. (c......This paper reports production and tribological testing of epoxy-matrix composites for dry-sliding conditions. The examined composites are produced using the following components: epoxy resin (EP), glass fiber weave (G), carbon/aramid hybrid weave (CA), PTFE particles and nano-scale CuO particles...

  14. Evaluation of Thermal and Thermomechanical Behaviour of Bio-Based Polyamide 11 Based Composites Reinforced with Lignocellulosic Fibres

    Directory of Open Access Journals (Sweden)

    Helena Oliver-Ortega

    2017-10-01

    Full Text Available In this work, polyamide 11 (PA11 and stone ground wood fibres (SGW were used, as an alternative to non-bio-based polymer matrices and reinforcements, to obtain short fibre reinforced composites. The impact of the reinforcement on the thermal degradation, thermal transitions and microstructure of PA11-based composites were studied. Natural fibres have lower degradation temperatures than PA11, thus, composites showed lower onset degradation temperatures than PA11, as well. The thermal transition and the semi-crystalline structure of the composites were similar to PA11. On the other hand, when SGW was submitted to an annealing treatment, the composites prepared with these fibres increased its crystallinity, with increasing fibre contents, compared to PA11. The differences between the glass transition temperatures of annealed and untreated composites decreased with the fibre contents. Thus, the fibres had a higher impact in the composites mechanical behaviour than on the mobility of the amorphous phase. The crystalline structure of PA11 and PA11-SGW composites, after annealing, was transformed to α’ more stable phase, without any negative impact on the properties of the fibres.

  15. Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

    Energy Technology Data Exchange (ETDEWEB)

    Arun Prakash, V.R., E-mail: vinprakash101@gmail.com; Rajadurai, A., E-mail: rajadurai@annauniv.edu.in

    2016-10-30

    Highlights: • Particles dimension have reduced using Ball milling process. • Importance of surface modification was explored. • Surface modification has been done to improve adhesion of fiber/particles with epoxy. • Mechanical properties has been increased by adding modified fiber and particles. • Thermal properties have been increased. - Abstract: In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and <100 nm has been prepared by high energy ball milling and sol-gel methods respectively. To enhance better dispersion of particles and improve adhesion of fibers and fillers with epoxy matrix surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee’s disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved

  16. Effect of Red Mud and Copper Slag Particles on Physical and Mechanical Properties of Bamboo-Fiber-Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    Sandhyarani Biswas

    2012-01-01

    Full Text Available In the present work, a series of bamboo-fiber-reinforced epoxy composites are fabricated by using red mud and copper slag particles as filler materials. A filler plays an important role in determining the properties and behavior of particulate composites. The effects of these two fillers on the mechanical properties of bamboo-epoxy composites are investigated. Comparative analysis shows that with the incorporation of these fillers, the tensile strength of the composites increases significantly, whereas the flexural strength and impact strength decrease with increase in filler content (red mud and copper slag fillers in the epoxy-bamboo fiber composites. The density and hardness are also affected by the type and content of filler particles. It is found that the addition of copper slag filler improves the hardness of the bamboo-epoxy composites, whereas the addition of red mud filler reduces the hardness value of bamboo-epoxy composites. The study reveals that the addition of copper slag filler in bamboo-epoxy composites shows better physical and mechanical properties as compared to the red-mud-filled composites.

  17. Embedded Fibre Bragg Grating Sensor Response Model: Crack Growing Detection in Fibre Reinforced Plastic Materials

    Science.gov (United States)

    Pereira, G.; Mikkelsen, L. P.; McGugan, M.

    2015-07-01

    This article presents a novel method to simulate the sensor output response of a Fibre Bragg Grating (FBG) sensor when embedded in a host material (Composite material or adhesive), during a crack growing/damage event. A finite element model of the crack growth mechanisms was developed, and different fracture modes were addressed. Then an output algorithm was developed to predict the sensor spectrum change during the different stages of the crack growing. Thus, it is possible to identify specific phenomenon that will only happen within the proximity of a crack, as compression field ahead the crack or non-uniform strain, and then identify the presence of such damage in the structure. Experimental tests were conducted in order to validate this concept and support the model. The FBG sensor response model was applied in a delamination of a Wind Turbine trailing edge, to demonstrate the applicability of this technique to more complicated structures, and to be used as a structural health monitoring design tool.

  18. Prestressing effect of cold-drawn short NiTi SMA fibres in steel reinforced mortar beams

    Science.gov (United States)

    Choi, Eunsoo; Kim, Dong Joo; Hwang, Jin-Ha; Kim, Woo Jin

    2016-08-01

    This study investigated the prestressing effect of cold-drawn short NiTi shape memory alloy (SMA) fibres in steel reinforced mortar beams. The SMA fibres were mixed with 1.5% volume content in a mortar matrix with the compressive strength of 50 MPa. The SMA fibres had an average length of 34 mm, and they were manufactured with a dog-bone shape: the diameters of the end- and middle-parts were 1.024 and 1.0 mm, respectively. Twenty mortar beams with the dimensions of 40 mm × 40 mm × 160 mm (B × H × L) were prepared. Two types of tests were conducted. One was to investigate the prestressing effect of the SMA fibres, and the beams with the SMA fibres were heated at the bottom. The other was to assess the bending behaviour of the beams prestressed by the SMA fibres. The SMA fibres induced upward deflection and cracking at the top surface by heating at the bottom; thus, they achieved an obvious prestressing effect. The beams that were prestressed by the SMA fibres did not show a significant difference in bending behaviour from that of the SMA fibre reinforced beams that were not subjected to heating. Stress analysis of the beams indicated that the prestressing effect decreased in relation to the cooling temperature.

  19. Tannin-based flax fibre reinforced composites for structural applications in vehicles

    Science.gov (United States)

    Zhu, J.; Abhyankar, H.; Nassiopoulos, E.; Njuguna, J.

    2012-09-01

    Innovation is often driven by changes in government policies regulating the industries, especially true in case of the automotive. Except weight savings, the strict EU regulation of 95% recyclable material-made vehicles drives the manufactures and scientists to seek new 'green materials' for structural applications. With handing at two major drawbacks (production cost and safety), ECHOSHELL is supported by EU to develop and optimise structural solutions for superlight electric vehicles by using bio-composites made of high-performance natural fibres and resins, providing enhanced strength and bio-degradability characteristics. Flax reinforced tannin-based composite is selected as one of the candidates and were firstly investigated with different fabric lay-up angles (non-woven flax mat, UD, [0, 90°]4 and [0, +45°, 90°, -45°]2) through authors' work. Some of the obtained results, such as tensile properties and SEM micrographs were shown in this conference paper. The UD flax reinforced composite exhibits the best tensile performance, with tensile strength and modulus of 150 MPa and 9.6 MPa, respectively. It was observed that during tension the oriented-fabric composites showed some delamination process, which are expected to be eliminated through surface treatment (alkali treatment etc.) and nanotechnology, such as the use of nano-fibrils. Failure mechanism of the tested samples were identified through SEM results, indicating that the combination of fibre pull-out, fibre breakage and brittle resins failure mainly contribute to the fracture failure of composites.

  20. Tannin-based flax fibre reinforced composites for structural applications in vehicles

    International Nuclear Information System (INIS)

    Zhu, J; Abhyankar, H; Nassiopoulos, E; Njuguna, J

    2012-01-01

    Innovation is often driven by changes in government policies regulating the industries, especially true in case of the automotive. Except weight savings, the strict EU regulation of 95% recyclable material-made vehicles drives the manufactures and scientists to seek new 'green materials' for structural applications. With handing at two major drawbacks (production cost and safety), ECHOSHELL is supported by EU to develop and optimise structural solutions for superlight electric vehicles by using bio-composites made of high-performance natural fibres and resins, providing enhanced strength and bio-degradability characteristics. Flax reinforced tannin-based composite is selected as one of the candidates and were firstly investigated with different fabric lay-up angles (non-woven flax mat, UD, [0, 90°] 4 and [0, +45°, 90°, −45°] 2 ) through authors' work. Some of the obtained results, such as tensile properties and SEM micrographs were shown in this conference paper. The UD flax reinforced composite exhibits the best tensile performance, with tensile strength and modulus of 150 MPa and 9.6 MPa, respectively. It was observed that during tension the oriented-fabric composites showed some delamination process, which are expected to be eliminated through surface treatment (alkali treatment etc.) and nanotechnology, such as the use of nano-fibrils. Failure mechanism of the tested samples were identified through SEM results, indicating that the combination of fibre pull-out, fibre breakage and brittle resins failure mainly contribute to the fracture failure of composites.

  1. Tensile behaviour of drawn tungsten wire used in tungsten fibre-reinforced tungsten composites

    Science.gov (United States)

    Riesch, J.; Feichtmayer, A.; Fuhr, M.; Almanstötter, J.; Coenen, J. W.; Gietl, H.; Höschen, T.; Linsmeier, Ch; Neu, R.

    2017-12-01

    In tungsten fibre-reinforced tungsten composites (Wf/W) the brittleness problem of tungsten is solved by utilizing extrinsic toughening mechanisms. The properties of the composite are very much related to the properties of the drawn tungsten wire used as fibre reinforcements. Its high strength and capability of ductile deformation are ideal properties facilitating toughening of Wf/W. Tensile tests have been used for determining mechanical properties and study the deformation and the fracture behaviour of the wire. Tests of as-fabricated and straightened drawn wires with a diameter between 16 and 150 μm as well as wire electrochemically thinned to a diameter of 5 μm have been performed. Engineering stress–strain curves and a microscopic analysis are presented with the focus on the ultimate strength. All fibres show a comparable stress–strain behaviour comprising necking followed by a ductile fracture. A reduction of the diameter by drawing leads to an increase of strength up to 4500 MPa as a consequence of a grain boundary hardening mechanism. Heat treatment during straightening decreases the strength whereas electrochemical thinning has no significant impact on the mechanical behaviour.

  2. An experimental investigation on flexural behaviour of fibre-reinforced pond ash-modified concrete

    Directory of Open Access Journals (Sweden)

    A. Sofi

    2015-12-01

    Full Text Available The flexural behaviour of plain and fibre-reinforced pond ash concrete (FRC beams under monotonic loading condition was analysed. Sixteen beams reinforced with top and bottom longitudinal deformed steel bars and transverse steel stirrups were tested. The beams were cast using three different percentages of pond ash, namely, 10%, 20% and 30% by weight of cement. Grooved type steel fibres were incorporated at different percentages of 0.5%, 1% and 2% by volume of concrete. Beams of cross section 150 mm × 150 mm and length 700 mm were tested in flexure under three-point bending system (one loading point plus two simple supports. Addition of fibres increased the failure load of the beams and ensured ductile behaviour. Ductility index and flexural rigidity of the beams were also studied. The predicted crack width (ACI 224 R-01 was compared with the measured crack width, and a good correlation was obtained.

  3. Bioresorbable screws reinforced with phosphate glass fibre: manufacturing and mechanical property characterisation.

    Science.gov (United States)

    Felfel, R M; Ahmed, I; Parsons, A J; Rudd, C D

    2013-01-01

    Use of bioresorbable screws could eliminate disadvantages associated with metals such as removal operations, corrosion, MRI interference and stress shielding. Mechanical properties of bioresorbable polymers alone are insufficient for load bearing applications application as screws. Thus, reinforcement is necessary to try and match or surpass the mechanical properties of cortical bone. Phosphate based glass fibres were used to reinforce polylactic acid (PLA) in order to produce unidirectionally aligned (UD) and unidirectionally plus randomly distributed (UD/RM) composite screws (P40 UD and P40 UD/RM). The maximum flexural and push-out properties for the composite screws (P40 UD and P40 UD/RM) increased by almost 100% in comparison with the PLA screws. While the pull-out strength and stiffness of the headless composite screws were ∼80% (strength) and ∼130% (stiffness) higher than for PLA, those with heads exhibited properties lower than those for PLA alone as a result of failure at the heads. An increase in the maximum shear load and stiffness for the composite screws (∼30% and ∼40%) in comparison to the PLA screws was also seen. Maximum torque for the PLA screws was ∼1000 mN m, while that for the composite screws were slightly lower. The SEM micrographs for P40 UD and P40 UD/RM screws revealed small gaps around the fibres, which were suggested to be due to buckling of the UD fibres during the manufacturing process. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Initial study of new bio-based epoxy in carbon fiber reinforced composite panel manufactured by vacuum assisted resin transfer moulding

    Science.gov (United States)

    Hafiezal, M. R. M.; Abdan, Khalina; Azaman, M. D.; Abidin Z., Z.; Hanafee, Z. M.

    2017-09-01

    This research paper is about carbon fiber reinforced composite panels with novel bio-based epoxy derived from Malaysian crude Jatropha oil (Epoxidized Jatropha Oil) which is mixed with synthetic epoxy as matrix. Its manufacturability performances were then verified by tensile test, flexural test and burnt off test. Two composite panels (fiber carbon with 100 wt. % of synthetic epoxy and fiber carbon with 18 wt. % bio-epoxy blend with synthetic epoxy) were fabricated by vacuum assisted resin transfer moulding. Samples were cut according to respective ASTM dimensioning and were tested. It was found that the new composite panel performed well in manufacturability aspect with fiber volume fraction achieved was around 40 - 45%. Although its tensile and flexural performances are a bit lower but comparable, we could conclude that the novel bio-epoxy as matrix in fiber carbon reinforcement could be fabricated by using this process for further research.

  5. In-plane mechanics of soft architectured fibre-reinforced silicone rubber membranes.

    Science.gov (United States)

    Bailly, L; Toungara, M; Orgéas, L; Bertrand, E; Deplano, V; Geindreau, C

    2014-12-01

    Silicone rubber membranes reinforced with architectured fibre networks were processed with a dedicated apparatus, allowing a control of the fibre content and orientation. The membranes were subjected to tensile loadings combined with continuous and discrete kinematical field measurements (DIC and particle tracking). These tests show that the mechanical behaviour of the membranes is hyperelastic at the first order. They highlight the influence of the fibre content and orientation on both the membrane in-plane deformation and stress levels. They also prove that for the considered fibrous architectures and mechanical loadings, the motion and deformation of fibres is an affine function of the macroscale transformation. These trends are fairly well described by the micromechanical model proposed recently in Bailly et al. (JMBBM, 2012). This result proves that these materials are very good candidates for new biomimetic membranes, e.g. to improve aortic analogues used for in vitro experiments, or existing textiles used for vascular (endo)prostheses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Comparative Investigation of Tungsten Fibre Nets Reinforced Tungsten Composite Fabricated by Three Different Methods

    Directory of Open Access Journals (Sweden)

    Linhui Zhang

    2017-07-01

    Full Text Available Tungsten fibre nets reinforced tungsten composites (Wf/W containing four net layers were fabricated by spark plasma sintering (SPS, hot pressing (HP and cold rolling after HP (HPCR, with the weight fraction of fibres being 17.4%, 10.5% and 10.5%, respectively. The relative density of the HPCRed samples is the highest (99.8% while that of the HPed composites is the lowest (95.1%. Optical and scanning electron microscopy and electron back scattering diffraction were exploited to characterize the microstructure, while tensile and hardness tests were used to evaluate the mechanical properties of the samples. It was found that partial recrystallization of fibres occurred after the sintering at 1800 °C. The SPSed and HPed Wf/W composites begin to exhibit plastic deformation at 600 °C with tensile strength (TS of 536 and 425 MPa and total elongation at break (TE of 11.6% and 23.0%, respectively, while the HPCRed Wf/W composites exhibit plastic deformation at around 400 °C. The TS and TE of the HPCRed Wf/W composites at 400 °C are 784 MPa and 8.4%, respectively. The enhanced mechanical performance of the Wf/W composites over the pure tungsten can be attributed to the necking, cracking, and debonding of the tungsten fibres.

  7. Durability of cracked fibre reinforced concrete exposed to freeze-thaw and deicing salt

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by subjecting beams to 4-point bending until a predefined crack width is reached. Specimens sawn from the beams after unloading are exposed to freeze-thaw and deic......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by subjecting beams to 4-point bending until a predefined crack width is reached. Specimens sawn from the beams after unloading are exposed to freeze......-thaw and deicing salt. The concrete has a water-powder ratio of 0.38 including both fly ash and silica fume. Both steel fibres (ZP, 0.4 vol%) and polypropylene fibres (PP, 1 vol%) are used as well as main reinforcement. The freeze-thaw test emphasizes the need for a critical evaluation of the mix design and mixing...... methods when designing FRC-structures. The scaling is increased by a factor 5 to 10 when adding fibres to the concrete while the air content is below 4% by volume. The variation of the scaling increases when adding fibres. Capillary water uptake in uncracked specimens of FRC was 20-30% higher at 1°C than...

  8. Investigation on Thermal Properties of Kenaf Fibre Reinforced Polyurethane Bio-Composites

    Science.gov (United States)

    Athmalingam, Mathan; Vicki, W. V.

    2018-01-01

    This research focuses on the effect of Kenaf fibre on thermal properties of Polyurethane (PU) reinforced kenaf bio-composites. The samples were prepared using the polymer casting method with different percentages of kenaf fibre content (5 wt%, 10 wt%, 15 wt%). The thermal properties of Kenaf/PU bio-composite are determined through the Thermogravimetric Analysis and Differential Scanning Calorimeter test. The TGA results revealed that 10 wt% Kenaf/PU bio-composite appeared to be more stable. DSC results show that the glass transition temperature (Tg) value of 10 wt% Kenaf/PU composite is significant to pure polyurethane. It can be said that the thermal stability of 10 wt% Kenaf/PU bio-composite exhibits higher thermal stability compared to other samples.

  9. Assessment of the exit defects in carbon fibre-reinforced plastic plates caused by drilling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Houjiang; Zhang Liangchi [Sydney Univ. (Australia). Dept. of Mechanical and Mechatronic Engineering; Chen Wuyi; Chen Dingchang [Beijing Univ. of Aeronautics and Astronautics, BJ (China). Dept. of Manufacturing Engineering

    2001-07-01

    This paper investigates the formation of the exit defects in carbon fibre-reinforced plates and characterizes their features in terms of drilling conditions. It was found that spalling and fuzzing are the major mechanisms of exit defects. The spalling, consisting of a main region and a secondary region, is caused by chisel and cutting edge actions, in which the former plays a key role. The fuzzing, however, exists in the cutting region where the included angle between the fibre direction of the surface layer and that of the cutting speed is acute. A severer spalling damage corresponds to a high spindle speed, a large feed rate and a great thrust force. Some empirical relationships, including a dimensionless formula, were developed for assessing the characteristic dimension of the spalling damage based on the known drilling conditions. (orig.)

  10. Application of WST-method fore fracture testing of fibre-reinforced concrete

    DEFF Research Database (Denmark)

    Löfgren, Ingemar; Olesen, John Forbes; Flansbjer, Mathias

    be drawn from this study are that: § the wedge-splitting test method is a suitable test method for assessment of fracture properties of steel fibre-reinforced concrete; § the test method is easy to handle and relatively fast to execute § the test can be run with CMOD-control or without, in a machine...... more than three times the fibre length; § using inverse analysis, the tensile fracture properties can be interpreted from the test result as a bi-linear stress-crack opening relationship.......To evaluate the reproducibility of the wedge-splitting test method and to provide guidelines, a round robin study was conducted in which three labs participated. The participating labs were: § DTU – the Technical University of Denmark, Department of Civil Engineering; § CTH – Chalmers University...

  11. Strain development in a filled epoxy resin curing under constrained and unconstrained conditions as assessed by Fibre Bragg Grating sensors

    Directory of Open Access Journals (Sweden)

    2007-04-01

    Full Text Available The influence of adhesion to the mould wall on the released strain of a highly filled anhydride cured epoxy resin (EP, which was hardened in an aluminium mould under constrained and unconstrained condition, was investigated. The shrinkage-induced strain was measured by fibre optical sensing technique. Fibre Bragg Grating (FBG sensors were embedded into the curing EP placed in a cylindrical mould cavity. The cure-induced strain signals were detected in both, vertical and horizontal directions, during isothermal curing at 75 °C for 1000 minutes. A huge difference in the strain signal of both directions could be detected for the different adhesion conditions. Under non-adhering condition the horizontal and vertical strain-time traces were practically identical resulting in a compressive strain at the end of about 3200 ppm, which is a proof of free or isotropic shrinking. However, under constrained condition the horizontal shrinkage in the EP was prevented due to its adhesion to the mould wall. So, the curing material shrunk preferably in vertical direction. This resulted in much higher released compressive strain signals in vertical (10430 ppm than in horizontal (2230 ppm direction. The constrained cured EP resins are under inner stresses. Qualitative information on the residual stress state in the molding was deduced by exploiting the birefringence of the EP.

  12. Hybrid MoS2/h-BN Nanofillers As Synergic Heat Dissipation and Reinforcement Additives in Epoxy Nanocomposites.

    Science.gov (United States)

    Ribeiro, Hélio; Trigueiro, João Paulo C; Silva, Wellington M; Woellner, Cristiano F; Owuor, Peter S; Cristian Chipara, Alin; Lopes, Magnovaldo C; Tiwary, Chandra S; Pedrotti, Jairo J; Villegas Salvatierra, Rodrigo; Tour, James M; Chopra, Nitin; Odeh, Ihab N; Silva, Glaura G; Ajayan, Pulickel M

    2017-09-26

    Two-dimensional (2D) nanomaterials as molybdenum disulfide (MoS 2 ), hexagonal boron nitride (h-BN), and their hybrid (MoS 2 /h-BN) were employed as fillers to improve the physical properties of epoxy composites. Nanocomposites were produced in different concentrations and studied in their microstructure, mechanical and thermal properties. The hybrid 2D mixture imparted efficient reinforcement to the epoxy leading to increases of up to 95% in tensile strength, 60% in ultimate strain, and 58% in Young's modulus. Moreover, an enhancement of 203% in thermal conductivity was achieved for the hybrid composite as compared to the pure polymer. The incorporation of MoS 2 /h-BN mixture nanofillers in epoxy resulted in nanocomposites with multifunctional characteristics for applications that require high mechanical and thermal performance.

  13. Analysis of the mechanical and thermal properties of jute and glass fiber as reinforcement epoxy hybrid composites.

    Science.gov (United States)

    Braga, R A; Magalhaes, P A A

    2015-11-01

    This work describes the study to investigate and compare the mechanical and thermal properties of raw jute and glass fiber reinforced epoxy hybrid composites. To improve the mechanical properties, jute fiber was hybridized with glass fiber. Epoxy resin, jute and glass fibers were laminated in three weight ratios (69/31/0, 68/25/7 and 64/18/19) respectively to form composites. The tensile, flexural, impact, density, thermal and water absorption tests were carried out using hybrid composite samples. This study shows that the addition of jute fiber and glass fiber in epoxy, increases the density, the impact energy, the tensile strength and the flexural strength, but decreases the loss mass in function of temperature and the water absorption. Morphological analysis was carried out to observe fracture behavior and fiber pull-out of the samples using scanning electron microscope. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Investigation of production of continuous off axis fibre reinforced thermoplastic material

    Science.gov (United States)

    McDonald, Philip C.

    Fibre reinforced composites have been used in the engineering industry for many years since the discovery of glass fibre in 1930 and its first use to reinforce phenolic resin to form Bakelite. Since then thermoplastic and thermosetting composites have spread into almost every industry from marine to aerospace, automotive to motorsport, luggage to the hobby industry and even fashion. This vast range of applications for composite materials is due to their high strength to weight ratio, excellent impact absorption properties, lack of corrosion, and reformability. In recent years a government directive has forced automotive manufacturers to look at lighter and more efficient vehicles to reduce carbon emissions. This can be achieved by using fibre reinforced thermoplastics to replace steel panels throughout the vehicle.Steel panels from a Nissan Qashqai were tested to determine the failure loads of each panel which the replacement thermoplastic material had to match or better. After extensive testing in a laboratory a tailored laminate lay-up with 5 laminate layers has been developed to replace structural steel components in vehicles. This tailored laminate stack up has a higher failure load than the steel components tested from the Nissan Qashqai while reducing the mass by at least 50%. The key drivers within the automotive industry are fuel savings and reduced vehicle mass, the use of this material and the potential it has in the mass production automotive industry can have a high impact on the overall mass of the vehicle which would invariably have a positive effect to the fuel consumption, thereby improving fuel economy in petrol and diesel vehicles, and increasing the range of electric vehicles.Throughout this project a prototype machine was developed and built to achieve mass production of this 5 ply laminate at a rate of more than 345,000 laminates per year with a processing cost of 3 1p making it available to the mass production market. The estimated production

  15. Investigation of mechanical properties of aluminium reinforced glass fibre polymer composites

    Science.gov (United States)

    Kumar, G. B. Veeresh; Pramod, R.

    2017-07-01

    This paper presents the recent work about reinforcing E-glass into Aluminium foil to attain high strength to weight ratio. Aluminium is corrosion resistant, light in weight and ductile, also when alloyed through other metals deliver the greater strengths as desirable for high-tech applications. The density of pure Aluminium is 2.7 g cm3. Electrical grade glass formally known as E-glass, is by far the most used fiber in reinforced plastic composites. It is a high strength material with light weight compared to steel and corrosive resistant. The matrix and reinforcement is bonded with a resin, named Araldite Ly556, which has density at 25 °C, 1.15-1.20 g cm3. Thus gives a good binding structure. In the present work, Aluminium, E-Glass and Epoxy are combined to fabricate a laminate by Hand-Lay process. Hand-lay is the oldest and simplest method used for producing reinforced plastic laminates. The fabricated metal matrix composites are tested for their mechanical properties. The metal laminate is found to render high strength, hardness, flexural strength and increased wear resistance. Further theoretical simulations was carried out to validate the experimental results.

  16. Mechanical properties of uniaxial natural fabric Grewia tilifolia reinforced epoxy based composites: Effects of chemical treatment

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2014-07-01

    Full Text Available The effects of chemical treatment on the mechanical, morphological, and chemical resistance properties of uniaxial natural fabrics, Grewia tilifolia/epoxy composites, were studied. In order to enhance the interfacial bonding between the epoxy matrix...

  17. Optimization of Recycled Glass Fibre-Reinforced Plastics Gear via Integration of the Taguchi Method and Grey Relational Analysis

    Science.gov (United States)

    Mizamzul Mehat, Nik; Syuhada Zakarria, Noor; Kamaruddin, Shahrul

    2018-03-01

    The increase in demand for industrial gears has resulted in the increase in usage of plastic-matrix composites particularly glass fibre-reinforced plastics as the gear materials. The usage of these synthetic fibers is to enhance the mechanical strength and the thermal resistance of the plastic gears. Nevertheless, the production of large quantities of these synthetic fibre-reinforced composites poses a serious threat to the ecosystem. Comprehending to this fact, the present work aimed at investigating the effects of incorporating recycled glass fibre-reinforced plastics in various compositions particularly on dimensional stability and mechanical properties of gear produced with diverse injection moulding processing parameters setting. The integration of Grey relational analysis (GRA) and Taguchi method was adopted to evaluate the influence of recycled glass fibre-reinforced plastics and variation in processing parameters on gear quality. From the experimental results, the blending ratio was found as the most influential parameter of 56.0% contribution in both improving tensile properties as well as in minimizing shrinkage, followed by mould temperature of 24.1% contribution and cooling time of 10.6% contribution. The results obtained from the aforementioned work are expected to contribute to accessing the feasibility of using recycled glass fibre-reinforced plastics especially for gear application.

  18. Structural optimization of the fibre-reinforced composite substructure in a three-unit dental bridge.

    Science.gov (United States)

    Shi, Li; Fok, Alex S L

    2009-06-01

    Failures of fixed partial dentures (FPDs) made of fibre-reinforced composites (FRC) have been reported in many clinical and in vitro studies. The types of failure include debonding at the composite-tooth interface, delamination of the veneering material from the FRC substructure and fracture of the pontic. The design of the FRC substructure, i.e. the position and orientation of the fibres, will affect the fracture resistance of the FPD. The purpose of this study was to find an optimal arrangement of the FRC substructure, by means of structural optimization, which could minimize the failure-initiating stresses in a three-unit FPD. A structural optimization method mimicking biological adaptive growth was developed for orthotropic materials such as FRC and incorporated into the finite element (FE) program ABAQUS. Using the program, optimization of the fibre positions and directions in a three-unit FPD was carried out, the aim being to align the fibre directions with those of the maximum principal stresses. The optimized design was then modeled and analyzed to verify the improvements in mechanical performance of the FPD. Results obtained from the optimization suggested that the fibres should be placed at the bottom of the pontic, forming a U-shape substructure that extended into the connectors linking the teeth and the pontic. FE analyses of the optimized design indicated stress reduction in both the veneering composite and at the interface between the veneer and the FRC substructure. The optimized design obtained using FE-based structural optimization can potentially improve the fracture resistance of FPDs by reducing some of the failure-initiating stresses. Optimization methods can therefore be a useful tool to provide sound scientific guidelines for the design of FRC substructures in FPDs.

  19. Development of a slim window frame made of glass fibre reinforced polyester

    DEFF Research Database (Denmark)

    Appelfeld, David; Hansen, Christian Skodborg; Svendsen, Svend

    2010-01-01

    This paper presents the development of an energy efficient window frame made of a glass fibre reinforced polyester (GFRP) material. Three frame proposals were considered. The energy and structural performances of the frames were calculated and compared with wooden and aluminium reference frames...... carried out an analysis of the potential energy savings of the frame. The calculations for a reference office building showed that the heating demand was considerably lower with a window made of GFRP than with the reference frames. It was found that GFRP is suitable for window frames, and windows made...

  20. Gliding arc discharge — Application for adhesion improvement of fibre reinforced polyester composites

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Teodoru, Steluta; Leipold, Frank

    2008-01-01

    production, and surface treatment. However, the application for adhesion improvement of structural materials has been rarely reported. In the present work, glass fibre reinforced polyester plates were treated using atmospheric pressure gliding arcs with high speed air flow for adhesion improvement...... with vinylester resin. It is found that the treatment increased the density of oxygen-containing polar functional groups at the composite surfaces, the polar component of the surface energy, and adhesive strength with a vinylester resin. The treatment effect highly depended on the temperatures of the electrodes...

  1. Fire resistance of ultra-high performance fibre reinforced concrete due to heating and cooling

    Directory of Open Access Journals (Sweden)

    Nazri Fadzli Mohamed

    2017-01-01

    Full Text Available This study investigated the performance of ultra-high performance fibre reinforced concrete (UHPFRC at elevated temperatures. The specimens were exposed to high temperatures, specifically 200, 400, and 600 °C, for 2 h.The fire resistance performance of the specimens was classified on the basis of their compressive strength, spalling, and weight loss; residual strength after heating was also examined. Results showed that UHPFRC processes excellent fire resistance in terms of flame spread and fire growth. While strength loss was not significant at low temperatures, the specimen subjected to high temperature spalled severly and showed deterioration because of heat.

  2. Effects of postcuring on mechanical properties of pultruded fiber-reinforced epoxy composites and the neat resin

    Science.gov (United States)

    Long, Edward R., Jr.; Long, Sheila Ann T.; Funk, Joan G.; Collins, William D.; Gray, Stephanie L.

    1989-01-01

    The effects of postcuring on mechanical properties of pultruded fiber-reinforced epoxy-resin composites have been investigated. Composites with carbon, glass, and aramid reinforcement fibers were individually studied. The epoxy was a commercially-available resin that was especially developed for pultrusion fabrication. The pultrusions were conducted at 400 F with postcures at 400, 450, 500, and 550 F. Measurements of the flexural, shear, and interlaminar fracture-toughness properties showed that significant postcuring can occur during the pultrusion process. All three mechanical properties were degraded by the higher (500 and 550 F) temperatures; photomicrographs suggest that the degradation was caused at the fiber-resin interface for all three fiber types.

  3. Highly transparent and rollable PVA-co-PE nanofibers synergistically reinforced with epoxy film for flexible electronic devices.

    Science.gov (United States)

    Xiong, Bing; Zhong, Weibing; Zhu, Qing; Liu, Ke; Li, Mufang; Sun, Gang; Wang, Dong

    2017-12-14

    The development of electronics towards a more functions-integrated, flexible and stretchable direction requires mechanically flexible substrates with high thermal and dimensional stability and optical transparency. Herein, rolls of an optically transparent PVA-co-PE nanofibrous membrane/epoxy composite with synergistically enhanced thermal stability, very low CTE, and outstanding mechanical properties are reported. The nanoscale size, the unique inter-stack structure, and the strong interfacial interactions between the PVA-co-PE nanofibers and the epoxy contribute to the synergistic effects. Because of the match between the refractive index (RI) of the PVA-co-PE nanofibers and the epoxy matrix, the visible light transmittance of nanocomposite film could be as high as 85% and the composite film was still optically transparent with a nanofiber loading content of up to 61.7 wt%. The break strength and compliance matrix of the composite film with a high fiber loading of 61.7 wt% increased by 2.3 times of that of the neat epoxy film and exceeded 3000 m 2 N -1 , respectively. PVA-co-PE nanofibers have a very low CTE value (3.634 × 10 -6 K -1 ) and could be applicable as a reinforcement to reduce the thermal expansion of epoxy. Furthermore, we developed a flexible alternating current electroluminescent (ACEL) device based on the transparent composite film and the experimental results showed that the transparent composite film could serve as substrate for flexible electronic devices. In addition, their electrical and optical properties were evaluated.

  4. A nonlinear theory for fibre-reinforced magneto-elastic rods

    Science.gov (United States)

    Ciambella, Jacopo; Favata, Antonino; Tomassetti, Giuseppe

    2018-01-01

    We derive a model for the finite motion of a fibre-reinforced magneto-elastic rod. The reinforcing particles are assumed weakly and uniformly magnetized, rigid and firmly embedded into the elastomeric matrix. We deduce closed-form expressions of the quasi-static motion of the rod in terms of the external magnetic field and of the body forces. The dependences of the motion on the shape of the inclusions, their orientation, their anisotropic magnetic properties and the Young modulus of the matrix are analysed and discussed. Two case studies are presented, in which the rod is used as an actuator suspended in a cantilever configuration. This work can foster new applications in the field of soft-actuators.

  5. Influence of steel fibres on the blast response of normal-strength and high-strength reinforced concrete columns

    Science.gov (United States)

    Hammoud, A.; Aoude, H.

    2017-09-01

    This paper examines the influence of steel fibres on the blast performance of normal-strength concrete and high-strength concrete columns. As part of the study, four normal-strength and high-strength concrete columns built with and without steel fibres are tested under simulated blast loads using the shock-tube facility at the University of Ottawa. The specimens include two columns built with plain concrete and two columns built with steel fibre-reinforced concrete. The results show that the addition of steel fibres in reinforced concrete columns leads to important enhancements in blast performance, with improved control of mid-span displacements at equivalent blasts and increased damage tolerance.

  6. A statistical analysis of fibre size and shape distribution after compounding in composites reinforced by natural fibres

    NARCIS (Netherlands)

    Moigne, Le N.; Oever, van den M.J.A.; Budtova, T.

    2011-01-01

    Using high resolution optical microscopy coupled with image analysis software and statistical methods, fibre length and aspect ratio distributions in polypropylene composites were characterized. Three types of fibres, flax, sisal and wheat straw, were studied. Number and surface weighted

  7. Short and long term behaviour of externally bonded fibre reinforced polymer laminates with bio-based resins for flexural strengthening of concrete beams

    Science.gov (United States)

    McSwiggan, Ciaran

    The use of bio-based resins in composites for construction is emerging as a way to reduce of embodied energy produced by a structural system. In this study, two types of bio-based resins were explored: an epoxidized pine oil resin blend (EP) and a furfuryl alcohol resin (FA) derived from corn cobs and sugar cane. Nine large-scale reinforced concrete beams strengthened using externally bonded carbon and glass fibre reinforced bio-based polymer (CFRP and GFRP) sheets were tested. The EP resin resulted in a comparable bond strength to conventional epoxy (E) when used in wet layup, with a 7% higher strength for CFRP. The FA resin, on the other hand, resulted in a very weak bond, likely due to concrete alkalinity affecting curing. However, when FA resin was used to produce prefabricated cured CFRP plates which were then bonded to concrete using conventional epoxy paste, it showed an excellent bond strength. The beams achieved an increase in peak load ranging from 18-54% and a 9-46% increase in yielding load, depending on the number of FRP layers and type of fibres and resin. Additionally, 137 concrete prisms with a mid-span half-depth saw cut were used to test CFRP bond durability, and 195 CFRP coupons were used to examine tensile strength durability. Specimens were conditioned in a 3.5% saline solution at 23, 40 or 50°C, for up to 240 days. Reductions in bond strength did not exceed 15%. Bond failure of EP was adhesive with traces of cement paste on CFRP, whereas that of FA was cohesive with a thicker layer of concrete on CFRP, suggesting that the bond between FA and epoxy paste is excellent. EP tension coupons had similar strength and modulus to E resin, whereas FA coupons had a 9% lower strength and 14% higher modulus. After 240 days of exposure, maximum reductions in tensile strength were 8, 19 and 10% for EP, FA and E resins, respectively. Analysis of Variance (ANOVA) was also performed to assess the significance of the reductions observed. High degrees of

  8. Design and evaluation of carbon fibre-reinforced launch packages with segmented, copper and molybdenum fibre armatures

    NARCIS (Netherlands)

    Koops, M.; Huijser, T.; Karthaus, W.

    1997-01-01

    Fibre armatures have been studied both dynamically and statically to gain insight in their electrothermal and mechanical behaviour. In the first part of this paper, the results of launch experiments with single and multi-segment copper and molybdenum fibre armatures integrated in carbon-fibre

  9. Influence of the physical structure of flax fibres on the mechanical properties of flax fibre reinforced polypropylene composites

    NARCIS (Netherlands)

    Oever, van den M.J.A.; Bos, H.L.; Kemenade, van M.J.J.M.

    2000-01-01

    This study investigates the influence of the physical structure of flax fibres on the mechanical properties of polypropylene (PP) composites. Due to their composite-like structure, flax fibres have relatively weak lateral bonds which are in particular present in flax fibres that are often used in

  10. Utilisation of Fibre Reinforced Sprayed Concrete for Primary Lining of the Považský Chlmec Tunnel

    Science.gov (United States)

    Baláž, M.; Uhrin, M.; Růžička, P.; Hilar, M.

    2017-09-01

    The aim of this paper is evaluation of the possibility to utilise fibre reinforced sprayed concrete for the primary lining of the Považský Chlmec Tunnel and comparison of such alternative design with the realised standard solution. The paper also includes a short description of the encountered geotechnical conditions and performed numerical modelling, which was necessary for determination of internal forces in the designed underground structure. The evaluation of fibre reinforced tunnel lining capacity is based on international standards. The paper also contains additional information about tunnel linings from fibre reinforced sprayed concrete such as standards and guidelines in the Czech Republic and abroad, project experience from the Czech Republic and abroad, details about design and construction or relevant laboratory testing.

  11. Use of steel fibres recovered from waste tyres as reinforcement in concrete: pull-out behaviour, compressive and flexural strength.

    Science.gov (United States)

    Aiello, M A; Leuzzi, F; Centonze, G; Maffezzoli, A

    2009-06-01

    The increasing amount of waste tyres worldwide makes the disposition of tyres a relevant problem to be solved. In the last years over three million tons of waste tyres were generated in the EU states [ETRA, 2006. Tyre Technology International - Trends in Tyre Recycling. http://www.etra-eu.org]; most of them were disposed into landfills. Since the European Union Landfill Directive (EU Landfill, 1999) aims to significantly reduce the landfill disposal of waste tyres, the development of new markets for the tyres becomes fundamental. Recently some research has been devoted to the use of granulated rubber and steel fibres recovered from waste tyres in concrete. In particular, the concrete obtained by adding recycled steel fibres evidenced a satisfactory improvement of the fragile matrix, mostly in terms of toughness and post-cracking behaviour. As a consequence RSFRC (recycled steel fibres reinforced concrete) appears a promising candidate for both structural and non-structural applications. Within this context a research project was undertaken at the University of Salento (Italy) aiming to investigate the mechanical behaviour of concrete reinforced with RSF (recycled steel fibres) recovered from waste tyres by a mechanical process. In the present paper results obtained by the experimental work performed up to now are reported. In order to evaluate the concrete-fibres bond characteristics and to determine the critical fibre length, pull-out tests were initially carried out. Furthermore compressive strength of concrete was evaluated for different volume ratios of added RSF and flexural tests were performed to analyze the post-cracking behaviour of RSFRC. For comparison purposes, samples reinforced with industrial steel fibres (ISF) were also considered. Satisfactory results were obtained regarding the bond between recycled steel fibres and concrete; on the other hand compressive strength of concrete seems unaffected by the presence of fibres despite their irregular

  12. Titanium Implant Osseointegration Problems with Alternate Solutions Using Epoxy/Carbon-Fiber-Reinforced Composite

    Directory of Open Access Journals (Sweden)

    Richard C. Petersen

    2014-12-01

    Full Text Available The aim of the article is to present recent developments in material research with bisphenyl-polymer/carbon-fiber-reinforced composite that have produced highly influential results toward improving upon current titanium bone implant clinical osseointegration success. Titanium is now the standard intra-oral tooth root/bone implant material with biocompatible interface relationships that confer potential osseointegration. Titanium produces a TiO2 oxide surface layer reactively that can provide chemical bonding through various electron interactions as a possible explanation for biocompatibility. Nevertheless, titanium alloy implants produce corrosion particles and fail by mechanisms generally related to surface interaction on bone to promote an inflammation with fibrous aseptic loosening or infection that can require implant removal. Further, lowered oxygen concentrations from poor vasculature at a foreign metal surface interface promote a build-up of host-cell-related electrons as free radicals and proton acid that can encourage infection and inflammation to greatly influence implant failure. To provide improved osseointegration many different coating processes and alternate polymer matrix composite (PMC solutions have been considered that supply new designing potential to possibly overcome problems with titanium bone implants. Now for important consideration, PMCs have decisive biofunctional fabrication possibilities while maintaining mechanical properties from addition of high-strengthening varied fiber-reinforcement and complex fillers/additives to include hydroxyapatite or antimicrobial incorporation through thermoset polymers that cure at low temperatures. Topics/issues reviewed in this manuscript include titanium corrosion, implant infection, coatings and the new epoxy/carbon-fiber implant results discussing osseointegration with biocompatibility related to nonpolar molecular attractions with secondary bonding, carbon fiber in vivo

  13. Titanium Implant Osseointegration Problems with Alternate Solutions Using Epoxy/Carbon-Fiber-Reinforced Composite.

    Science.gov (United States)

    Petersen, Richard C

    2014-12-01

    The aim of the article is to present recent developments in material research with bisphenyl-polymer/carbon-fiber-reinforced composite that have produced highly influential results toward improving upon current titanium bone implant clinical osseointegration success. Titanium is now the standard intra-oral tooth root/bone implant material with biocompatible interface relationships that confer potential osseointegration. Titanium produces a TiO 2 oxide surface layer reactively that can provide chemical bonding through various electron interactions as a possible explanation for biocompatibility. Nevertheless, titanium alloy implants produce corrosion particles and fail by mechanisms generally related to surface interaction on bone to promote an inflammation with fibrous aseptic loosening or infection that can require implant removal. Further, lowered oxygen concentrations from poor vasculature at a foreign metal surface interface promote a build-up of host-cell-related electrons as free radicals and proton acid that can encourage infection and inflammation to greatly influence implant failure. To provide improved osseointegration many different coating processes and alternate polymer matrix composite (PMC) solutions have been considered that supply new designing potential to possibly overcome problems with titanium bone implants. Now for important consideration, PMCs have decisive biofunctional fabrication possibilities while maintaining mechanical properties from addition of high-strengthening varied fiber-reinforcement and complex fillers/additives to include hydroxyapatite or antimicrobial incorporation through thermoset polymers that cure at low temperatures. Topics/issues reviewed in this manuscript include titanium corrosion, implant infection, coatings and the new epoxy/carbon-fiber implant results discussing osseointegration with biocompatibility related to nonpolar molecular attractions with secondary bonding, carbon fiber in vivo properties, electrical

  14. Mechanical behaviour of steel fibre-reinforced alkali activated slag concrete

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2009-03-01

    Full Text Available This study addressed the mechanical behaviour of a steel fibre-reinforced alternative concrete made from waterglass (Na2SiO3.nH2O+NaOH- activated Colombian blast furnace slag. The mixes studied were prepared with 400 kg of cement and the fibres were added in proportions of 40 and 120 kg per cubic metre of concrete. 7-, 14- and 28-day concrete was tested for compressive, splitting tensile and flexural strength. The results obtained showed that adding steel fibre to alkaline concrete lowered early age compressive strength, and that this decline was more intense with rising volumes of steel. Flexural and splitting tensile strength grew, however, enhancing the toughness of the material. As a general rule, the mechanical strength of the plain and fibre-reinforced alkaline concretes studied was higher than exhibited by conventional ordinary Portland cement concrete prepared with similar proportions of cement and fibre.En este estudio se investigó el comportamiento mecánico de hormigones alternativos reforzados con fibras de acero, basados en una escoria siderúrgica colombiana activada alcalinamente con waterglass (Na2SiO3.nH2O+NaOH. Las mezclas en estudio fueron preparadas con 400 kg de cemento y las fibras fueron incorporadas en proporciones de 40 kg y 120 kg por metro cúbico de hormigón, respectivamente. Se evaluó el comportamiento mecánico de los hormigones frente a esfuerzos de compresión, tracción indirecta y flexión a edades de curado de 7, 14 y 28 días. Los resultados obtenidos indican que la incorporación de fibras de acero en los hormigones alcalinos reduce la resistencia a la compresión a edades tempranas siendo superior la pérdida de resistencia a mayores volúmenes de fibra incorporados, mientras que la resistencia a la flexión y tracción indirecta se incrementan significativamente, mejorando la tenacidad del material. En términos generales, es posible concluir que el comportamiento mecánico exhibido por los hormigones

  15. Synthesis and Characterization of Fibre Reinforced Silica Aerogel Blankets for Thermal Protection

    Directory of Open Access Journals (Sweden)

    S. Chakraborty

    2016-01-01

    Full Text Available Using tetraethoxysilane (TEOS as the source of silica, fibre reinforced silica aerogels were synthesized via fast ambient pressure drying using methanol (MeOH, trimethylchlorosilane (TMCS, ammonium fluoride (NH4F, and hexane. The molar ratio of TEOS/MeOH/(COOH2/NH4F was kept constant at 1 : 38 : 3.73 × 10−5 : 0.023 and the gel was allowed to form inside the highly porous meta-aramid fibrous batting. The wet gel surface was chemically modified (silylation process using various concentrations of TMCS in hexane in the range of 1 to 20% by volume. The fibre reinforced silica aerogel blanket was obtained subsequently through atmospheric pressure drying. The aerogel blanket samples were characterized by density, thermal conductivity, hydrophobicity (contact angle, and Scanning Electron Microscopy. The radiant heat resistance of the aerogel blankets was examined and compared with nonaerogel blankets. It has been observed that, compared to the ordinary nonaerogel blankets, the aerogel blankets showed a 58% increase in the estimated burn injury time and thus ensure a much better protection from heat and fire hazards. The effect of varying the concentration of TMCS on the estimated protection time has been examined. The improved thermal stability and the superior thermal insulation of the flexible aerogel blankets lead to applications being used for occupations that involve exposure to hazards of thermal radiation.

  16. Preparation And Properties Of Bionanocomposite Films Reinforced With Nanocellulose Isolated From Moroccan Alfa Fibres

    Directory of Open Access Journals (Sweden)

    Youssef Benyoussif

    2015-09-01

    Full Text Available Nanocellulose (NC were extracted from the Moroccan Alfa plant (Stipa tenacissima L. and characterised. These Alfa cellulosic nanoparticles were used as reinforcing phase to prepare bionanocomposite films using carboxymethyl cellulose as matrix. These films were obtained by the casting/evaporation method. The crystallinity of NC was analysed by X-ray diffraction, the dimension of NC by atomic force microscopy, molecular interactions due to incorporation of NC in carboxymethyl cellulose (CMC matrix were supported by Fourier transforms infrared (FTIR spectroscopy. The properties of the ensuing bionanocomposite films were investigated using tensile tests, water vapour permeability (WVP study and thermogravimetric analysis. With the progress of purification treatment of cellulose, the crystallinity is improved compared to the untreated fibres; this can be explained by the disappearance of the amorphous areas in cellulose chain of the plant. Consequently, the tensile modulus and tensile strength of CMC film increased by 60 and 47%, respectively, in the bionanocomposite films with 10 wt% of NC, and decrease by 8.6% for WVP with the same content of NC. The NC obtained from the Moroccan Alfa fibres can be used as a reinforcing agent for the preparation of bionanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials.

  17. Elaboration of fiber-reinforced metallic materials; Elaboration des materiaux metalliques renforces par des fibres

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.M. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-08-01

    A bibliographic study on the elaboration of fiber reinforced metallic materials is presented in three parts: the theory of fiber reinforcement of metals in summarized, with emphasis on the mechanical and geometric factors which govern the behaviour and the performances to be expected from a given composite material; a second part is devoted to the study of the physical and chemical factors related to the structural stability of the material. Finally, the various processes of fabrication of such composites are presented and discussed. (author) [French] Cette etude bibliographique de l'elaboration des materiaux metalliques renforces par des fibres, comprend trois parties. Dans la premiere partie, la theorie du renforcement des metaux par des fibres est resumee de maniere a mettre en lumiere les facteurs mecaniques et geometriques qui determinent le comportement et les performances que l'on peut attendre d'un composite donne. La seconde partie est consacree a l'etude des facteurs physico-chimiques qui determinent la stabilite structurale d'un composite. Enfin, la troisieme partie est constituee par l'expose des differentes methodes d'elaboration des composites. (auteur)

  18. An Experimental Study on Concrete Flat Slabs Prestressed with Carbon Fibre Reinforced Polymer Sheets

    Directory of Open Access Journals (Sweden)

    Yin Shen

    2015-01-01

    Full Text Available Carbon fibre reinforced polymer (CFRP is currently used to reinforce buildings in civil engineering in the common forms of sheets, while the utilization efficiency of a CFRP materials greatly decreased when the CFRP material is directly bonded to the structure because of the lack of the effect of the exertion of a prestress. A paper spool-inspired anchoring method is proposed to overcome the shearing problem in the anchoring system through the friction between layers. Anchoring and jack-up tensioning devices for CFRP sheets are also designed and produced. A prestress is successfully applied to single and multiple CFRP sheets (80% tensioning strength is achieved, thus verifying the tensioning effect of the prestress. Based on these results, prestressed concrete flat slabs were designed with pretensioned CFRP sheets. The corresponding mechanical properties of the concrete flat slabs are tested to verify the feasibility of using CFRP sheets to apply a prestress. The results show that the uniformity of the fibre stress during the tensioning of the CFRP sheet is the key to the success of the application of the prestress.

  19. Adhesive Bonding Techniques in Hybrid Structures Made from Fibre Reinforced Polymeric Composites and Concrete

    Directory of Open Access Journals (Sweden)

    Ruxandra Oltean

    2009-01-01

    Full Text Available Mechanical joining techniques are used in construction industry all over the world on a daily basis. A further method of joining has proven to be highly successful – adhesive bonding. Known for thousands of years, adhesive bonding has become as important as other joining techniques as a result of the pace of developments in recent years. In many areas, this bonding technology has become a key technology. Virtually, all solid materials can be connected with one another using adhesives. Although bonding fibre reinforced polymeric composites to the concrete substrate is a relatively simple technique, the proper installation of the fibre reinforced polymeric composites is essential to ensure the adequate performance of the hybrid system. Since the installation procedures differ from one system to another, appropriate specifications will be clearly presented. The paper will include requirements to provide a quality joint assembly, meaning the special pre-treatments of the concrete surface. The material to be bonded is cleaned and prepared so that adhesives can adhere better to them.

  20. Particulate Filled Composite Plastic Materials from Recycled Glass Fibre Reinforced Plastics

    Directory of Open Access Journals (Sweden)

    Aare ARUNIIT

    2011-09-01

    Full Text Available Glass fibre reinforced plastic (GFRP scrap consisted of acrylic plastic with glass fibre reinforcement in polyester resin matrix was used in our experiments. The multi-functional DS-series disintegrator mills were used for mechanical processing of GFRP scrap. Preceding from the results characterization of the milled powder particles size, shape and other properties the numerical algorithm for modelling of the density of the new filler material was developed. The main goal of the current study is to develop new particulate filled composite plastic material from recycled GFRP scrap. With recovered plastic powder material the higher filler content in polyester resin matrix can be achieved. The new composite is modelled on basis of the properties of new material. Such an approach requires tests of the new material. The considered target characteristics of the new material are the tensile strength, elongation at break and the cost. The multicriteria optimization problem has been formulated and solved by use of physical programming techniques and Pareto optimality concept. The designed new composites were manufactured in different mixing ratios of powder and binder agent. The strength and stiffness properties of new composite material were tested. http://dx.doi.org/10.5755/j01.ms.17.3.593

  1. Effect of the surface roughness on interfacial properties of carbon fibers reinforced epoxy resin composites

    International Nuclear Information System (INIS)

    Song Wei; Gu Aijuan; Liang Guozheng; Yuan Li

    2011-01-01

    The effect of the surface roughness on interfacial properties of carbon fibers (CFs) reinforced epoxy (EP) resin composite is studied. Aqueous ammonia was applied to modify the surfaces of CFs. The morphologies and chemical compositions of original CFs and treated CFs (a-CFs) were characterized by Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS). Compared with the smooth surface of original CF, the surface of a-CF has bigger roughness; moreover, the roughness increases with the increase of the treating time. On the other hand, no obvious change in chemical composition takes place, indicating that the treating mechanism of CFs by aqueous ammonia is to physically change the morphologies rather than chemical compositions. In order to investigate the effect of surface roughness on the interfacial properties of CF/EP composites, the wettability and Interfacial Shear Strength (IFSS) were measured. Results show that with the increase of the roughness, the wettabilities of CFs against both water and ethylene glycol improves; in addition, the IFSS value of composites also increases. These attractive phenomena prove that the surface roughness of CFs can effectively overcome the poor interfacial adhesions between CFs and organic matrix, and thus make it possible to fabricate advanced composites based on CFs.

  2. Effect of Filler Loading on Mechanical and Tribological Properties of Wood Apple Shell Reinforced Epoxy Composite

    Directory of Open Access Journals (Sweden)

    Ojha Shakuntala

    2014-01-01

    Full Text Available During the last century, natural fibers and particulates are used as reinforcement in polymer composite that has been continuously growing in the composite industry. This polymer matrix composite has wide range of applications in hostile environment where they are exposed to external attacks such as solid particle erosion. Also, the mechanical properties of different polymer composites show the best alternate to replace the metal material. In the present investigation, an attempt has been made to improve the mechanical and tribological behaviour of polymer matrix composite using wood apple shell particles as a filler material in polymer matrix. Also the temperature variation of the dynamic-mechanical parameters of epoxy matrix composites incorporated with 5, 10, 15, and 20 wt% of wood apple shell particles was investigated by DMA test. It is clearly observed that the incorporation of wood apple shell particles tends to increase the tensile strength, flexural strength, erosive wear resistance, and viscoelastic stiffness of the polymer composite. To validate the results, SEM of the polymer matrix composite has been studied.

  3. Behaviour of alkaline cement mortars reinforced with acrylic and polypropylene fibres

    Directory of Open Access Journals (Sweden)

    Puertas, P.

    2000-09-01

    Full Text Available In the present work, the behaviour of alkaline cement mortars reinforced with fibres of different nature (acrylic and polypropylene fibres is studied. Also the chemical stability of those fibres in strong alkaline medium has been investigated. Three different matrixes have been used: glass blast furnace slag activated with NaOH 2M (room temperature, 22 ºC; fly ash activated with NaOH 8M, cured at 85ºC during 24 hours and 50% fly ash / 50% slag activated with NaOH 8M, room temperature. The fibre content was 0,2 and 1% in mortar volume. The tests carried out were: tenacity and tenacity index, impact resistance and drying shrinkage. On the specimens tested, a microstructural study by SEM/EDX was carried out. The results obtained have demonstrated the following: a The acrylic and polypropylene fibres are stable in strong basic media, although the first undergo hydrolysis/ hydration processes showed by the alteration of the surface texture, b with low fibre contents (0,2% in volume, tenacity and tenacity index of these mortars remain unaffected. With higher contents (1%, an increase of the corresponding values is produced. This increment is higher in mortars with alkaline activated slag, c For the three matrixes studied, the polypropylene fibres increase the impact strength in higher degree than the acrylic ones. The reinforcement effect is more significative in matrix A and when the fibre content is 1% in volume, d the shrinkage of these mortars is modified depending on the matrix and fibre type. In mortars of activated slag, fibres do not reduce the shrinkage. In mortars of activated fly ash reinforced with acrylic fibres, shrinkage is lower than those containing polypropylene fibres are. Finally, in mortars of fly ash/ activated slag, the two fibres decrease the drying shrinkage.

    En el presente trabajo se estudia el comportamiento de morteros de cementos alcalinos reforzados con fibras de distinta naturaleza (acrílica y de polipropileno

  4. Freestanding nanocellulose-composite fibre reinforced 3D polypyrrole electrodes for energy storage applications

    Science.gov (United States)

    Wang, Zhaohui; Tammela, Petter; Zhang, Peng; Huo, Jinxing; Ericson, Fredric; Strømme, Maria; Nyholm, Leif

    2014-10-01

    It is demonstrated that 3D nanostructured polypyrrole (3D PPy) nanocomposites can be reinforced with PPy covered nanocellulose (PPy@nanocellulose) fibres to yield freestanding, mechanically strong and porosity optimised electrodes with large surface areas. Such PPy@nanocellulose reinforced 3D PPy materials can be employed as free-standing paper-like electrodes in symmetric energy storage devices exhibiting cell capacitances of 46 F g-1, corresponding to specific electrode capacitances of up to ~185 F g-1 based on the weight of the electrode, and 5.5 F cm-2 at a current density of 2 mA cm-2. After 3000 charge/discharge cycles at 30 mA cm-2, the reinforced 3D PPy electrode material also showed a cell capacitance corresponding to 92% of that initially obtained. The present findings open up new possibilities for the fabrication of high performance, low-cost and environmentally friendly energy-storage devices based on nanostructured paper-like materials.It is demonstrated that 3D nanostructured polypyrrole (3D PPy) nanocomposites can be reinforced with PPy covered nanocellulose (PPy@nanocellulose) fibres to yield freestanding, mechanically strong and porosity optimised electrodes with large surface areas. Such PPy@nanocellulose reinforced 3D PPy materials can be employed as free-standing paper-like electrodes in symmetric energy storage devices exhibiting cell capacitances of 46 F g-1, corresponding to specific electrode capacitances of up to ~185 F g-1 based on the weight of the electrode, and 5.5 F cm-2 at a current density of 2 mA cm-2. After 3000 charge/discharge cycles at 30 mA cm-2, the reinforced 3D PPy electrode material also showed a cell capacitance corresponding to 92% of that initially obtained. The present findings open up new possibilities for the fabrication of high performance, low-cost and environmentally friendly energy-storage devices based on nanostructured paper-like materials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c

  5. Size and shape effect of specimen on the compressive strength of HPLWFC reinforced with glass fibres

    Directory of Open Access Journals (Sweden)

    Ali Jihad Hamad

    2017-10-01

    Full Text Available High performance lightweight foamed concrete (HPLWFC have a structural strength with low density and high flowability. HPLWFC is used in modern concrete technology and extensively in the construction applications of high-rise buildings, long-span concrete structures and road sub-bases among others. This present work investigated the effect of size and shape specimen on the compressive strength of HPLWFC reinforced with glass fibres. Foam agent (organic material was used to obtain lightweight concrete. The volume fractions of the glass fibres used were: 0.0%, 0.06%, 0.2%, 0.4%, and 0.6% by total volume of concrete. The fresh properties of HPLWFC were measured by flowability and fresh density tests. In this study, the size and shape of specimens used for compressive strength were cubes by size (150 × 150 × 150, 100 × 100 × 100 and 50 × 50 × 50 mm and cylinders by size (150 × 300 and 100 × 200 mm. The results of HPLWFC mixes showed the increase in the compressive strength for all sizes of specimens with glass fibre content. The small size of specimens gave higher compressive strength in comparison with other sizes. The disparity in the compressive strength for two sizes and shapes (cubes and cylinders were reduced with a rise in the volume fraction of the glass fibres.

  6. Analytical Modeling for Mechanical Strength Prediction with Raman Spectroscopy and Fractured Surface Morphology of Novel Coconut Shell Powder Reinforced: Epoxy Composites

    Science.gov (United States)

    Singh, Savita; Singh, Alok; Sharma, Sudhir Kumar

    2017-06-01

    In this paper, an analytical modeling and prediction of tensile and flexural strength of three dimensional micro-scaled novel coconut shell powder (CSP) reinforced epoxy polymer composites have been reported. The novel CSP has a specific mixing ratio of different coconut shell particle size. A comparison is made between obtained experimental strength and modified Guth model. The result shows a strong evidence for non-validation of modified Guth model for strength prediction. Consequently, a constitutive modeled equation named Singh model has been developed to predict the tensile and flexural strength of this novel CSP reinforced epoxy composite. Moreover, high resolution Raman spectrum shows that 40 % CSP reinforced epoxy composite has high dielectric constant to become an alternative material for capacitance whereas fractured surface morphology revealed that a strong bonding between novel CSP and epoxy polymer for the application as light weight composite materials in engineering.

  7. Development study of concrete reinforcement made of aramid fiber-reinforced plastic rods with high radiation resistance. 1. Epoxy resin compounds with a handling at room temperature impregnation

    International Nuclear Information System (INIS)

    Udagawa, Akira; Seguchi, Tadao; Moriya, Toshio; Matsubara, Sumiyuki; Hongou, Yoshihiko

    1999-03-01

    Aramid fiber-reinforced plastic (ArFRP) rods were developed in order to avoid from conduction current and/or magnetization of the metallic reinforcement using concrete constructions. For the polymer matrix, new epoxy resin compounds consist of tetraglycidyl diaminodiphenylmethane (30%), diglycidyl ether of bisphenol-A (60%), styrene oxide (10%) and aromatic diamine as a hardner were found to be the best formulation, and which were easily impregnated to the aramid fiber braiding yarn at room temperature. The ArFRP rods has a high radiation resistance, and the tensile strength was maintained to 98% (1.45 GPa) after irradiation dose of 100 MGy (absorbed energy MJ/kg), which is available for the reinforcement of concrete construction for the house of fusion reactor with super conducting magnets. (author)

  8. Testing temperature on interfacial shear strength measurements of epoxy resins at different mixing ratios

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Thomason, James L.; Minty, Ross

    2015-01-01

    The interfacial properties as Interfacial Shear Stress (IFSS) in fibre reinforced polymers are essential for further understanding of the mechanical properties of the composite. In this work a single fibre testing method is used in combination with an epoxy matrix made from Araldite 506 epoxy resin...... and triethylenetetramine (TETA) hardener. The IFSS was measured by a microbond test developed for a Thermal Mechanical Analyzer. The preliminary results indicate that IFSS has an inverse dependency of both testing temperature and the mixing ratio of hardener and epoxy resin. Especially interesting was the decreasing...

  9. Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites

    Directory of Open Access Journals (Sweden)

    Andrey E. Krauklis

    2018-04-01

    Full Text Available Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer–Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described.

  10. Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites.

    Science.gov (United States)

    Krauklis, Andrey E; Gagani, Abedin I; Echtermeyer, Andreas T

    2018-04-11

    Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR) spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR) spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer-Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described.

  11. Vegetable fibres from agricultural residues as thermo-mechanical reinforcement in recycled polypropylene-based green foams.

    Science.gov (United States)

    Ardanuy, Mònica; Antunes, Marcelo; Velasco, José Ignacio

    2012-02-01

    Novel lightweight composite foams based on recycled polypropylene reinforced with cellulosic fibres obtained from agricultural residues were prepared and characterized. These composites, initially prepared by melt-mixing recycled polypropylene with variable fibre concentrations (10-25 wt.%), were foamed by high-pressure CO(2) dissolution, a clean process which avoids the use of chemical blowing agents. With the aim of studying the influence of the fibre characteristics on the resultant foams, two chemical treatments were applied to the barley straw in order to increase the α-cellulose content of the fibres. The chemical composition, morphology and thermal stability of the fibres and composites were analyzed. Results indicate that fibre chemical treatment and later foaming of the composites resulted in foams with characteristic closed-cell microcellular structures, their specific storage modulus significantly increasing due to the higher stiffness of the fibres. The addition of the fibres also resulted in an increase in the glass transition temperature of PP in both the solid composites and more significantly in the foams. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Mechanical, morphological and structural properties of cellulose nanofibers reinforced epoxy composites.

    Science.gov (United States)

    Saba, N; Mohammad, F; Pervaiz, M; Jawaid, M; Alothman, O Y; Sain, M

    2017-04-01

    Present study, deals about isolation and characterization of cellulose nanofibers (CNFs) from the Northern Bleached Softwood Kraft (NBSK) pulp, fabrication by hand lay-up technique and characterization of fabricated epoxy nanocomposites at different filler loadings (0.5%, 0.75%, 1% by wt.). The effect of CNFs loading on mechanical (tensile, impact and flexural), morphological (scanning electron microscope and transmission electron microscope) and structural (XRD and FTIR) properties of epoxy composites were investigated. FTIR analysis confirms the introduction of CNFs into the epoxy matrix while no considerable change in the crystallinity and diffraction peaks of epoxy composites were observed by the XRD patterns. Additions of CNFs considerably enhance the mechanical properties of epoxy composites but a remarkable improvement is observed for 0.75% CNFs as compared to the rest epoxy nanocomposites. In addition, the electron micrographs revealed the perfect distribution and dispersion of CNFs in the epoxy matrix for the 0.75% CNFs/epoxy nanocomposites, while the existence of voids and agglomerations were observed beyond 0.75% CNFs filler loadings. Overall results analysis clearly revealed that the 0.75% CNFs filler loading is best and effective with respect to rest to enhance the mechanical and structural properties of the epoxy composites. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. In situ study of the epoxy cure process using a fibre-optic sensor

    Czech Academy of Sciences Publication Activity Database

    Chailleux, E.; Salvia, M.; Jaffrezic-Renault, N.; Matějec, Vlastimil; Kašík, Ivan

    2001-01-01

    Roč. 10, č. 2 (2001), s. 194-202 ISSN 0964-1726. [SPIE Annual International Symposium on Smart Structures and Materials /8./. Newport Beach, 04.03.2001-08.03.2001] R&D Projects: GA ČR GA102/99/0548; GA AV ČR KSK2067107 Projekt 07/01:4074 Institutional research plan: CEZ:AV0Z2067918 Keywords : fibre optic sensors * process monitoring Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.199, year: 2001

  14. Thermal and physico-mechanical stability of recycled high density polyethylene reinforced with oil palm fibres

    Directory of Open Access Journals (Sweden)

    R.O. Medupin

    2017-12-01

    Full Text Available The impressive physical and mechanical properties achievable with organic fillers make them a good choice for polymer composite reinforcement. In this study, oil palm fibres (OPF, often hardly thought of as having any reasonable economic value in developing economy was used as reinforcing fillers in recycled high density polyethylene (rHDPE. Thermal behaviour, physical and mechanical stability of rHDPE filled with OPF have been studied. Fourier Transform Infrared Spectroscopy (FTIR results present band spectra characteristic of OH stretching vibration in the cellulose of the fibre material. The absorption bands of the spectra are attributed to the presence of stretching vibration of CO group mostly found in the form of hemicelluloses and lignin structure in the fibre. Upon examination of the test specimens produced through compression moulding technique, it was found that the addition of OPF (filler into rHDPE (matrix increased the composites’ water absorption rate linearly for the first 16 days of exposure to the water environment. Stability was achieved for all the materials after this period. Thermal studies of the various compositions (OPF/rHDPE: 5/95, 10/90, 15/85, 20/80 and 25/75 using derivative thermogravimetric analysis (DTGA showed two main degradation peaks at 490 °C and 380 °C. The mechanical study revealed that the composite with 20 wt% filler contents was the most eco-friendly and had the best mechanical properties while that with 25 wt% was the most thermally stable. This material was thermally stable up to approximately 330 °C. Microstructure examination of the different components of the composites further explains the reason for good physical and mechanical strength of the sample with 20 wt% filler. It can, therefore, be inferred from the results of the various analyses conducted that OPF is a good reinforcing phase for rHDPE and a potential material for construction and automotive industries.

  15. Experimental investigation of the relation between damage at the concrete-steel interface and initiation of reinforcement corrosion in plain and fibre reinforced concrete

    International Nuclear Information System (INIS)

    Michel, A.; Solgaard, A.O.S.; Pease, B.J.; Geiker, M.R.; Stang, H.; Olesen, J.F.

    2013-01-01

    Highlights: •Cracked plain and steel fibre reinforced concrete flexural beams were investigated. •“Instrumented rebars” provided location- and time-dependent corrosion measurements. •Interfacial condition can be used as a reliable indicator to quantify the risk of corrosion. •Simulated interfacial conditions are in very good agreement with all experimental observations. -- Abstract: Cracks in covering concrete are known to hasten initiation of steel corrosion in reinforced concrete structures. To minimise the impact of cracks on the deterioration of reinforced concrete structures, current approaches in (inter)national design codes often limit the concrete surface crack width. Recent investigations however, indicate that the concrete-reinforcement interfacial condition is a more fundamental criterion related to reinforcement corrosion. This work investigates the relation between macroscopic damage at the concrete-steel interface and corrosion initiation of reinforcement embedded in plain and fibre reinforced concrete. Comparisons of experimental and numerical results indicate a strong correlation between corrosion initiation and interfacial condition

  16. Thermal properties of oil palm nano filler/kenaf reinforced epoxy hybrid nanocomposites

    Science.gov (United States)

    Saba, N.; Paridah, M. T.; Abdan, K.; Ibrahim, N. A.

    2016-11-01

    The aim of this research study was to fabricate nano oil palm empty fruit bunch (OPEFB)/kenaf/epoxy hybrid nanocomposites and to make comparative study on the thermal properties of nano OPEFB/kenaf/epoxy hybrid nanocomposites with the montmorillonite (MMT)/kenaf/epoxy hybrid nanocomposites and organically modified MMT (OMMT)/kenaf/epoxy hybrid nanocomposites. Epoxy based kenaf hybrid nanocomposites was prepared by dispersing the nano filler (nano OPEFB filler, MMT, OMMT) at 3% loading through high speed mechanical stirrer followed by hand lay-up technique. Thermal properties of hybrid nanocomposites were analyzed through thermogravimetry analyzer (TGA), and differential scanning calorimetry (DSC). Obtained results specified that addition of nano OPEFB filler improves the thermal stability and char yield of kenaf/epoxy composites. Furthermore, the increase in decomposition temperature by the nano OPEFB filler was quite comparable to the MMT/kenaf/epoxy but relatively less than OMMT/kenaf/epoxy hybrid nanocomposites. We concluded from overall consequences that the nano OPEFB filler can be used as the promising and innovative alternative of existing expensive nano filler, with relatively lesser impact on the environment having marked pronounced impact on the construction, automotive, aerospace, electronics and semiconducting sectors as future industries based on bio-wastes with satisfactory light weight and thermal stability on other side.

  17. Go with the flow: conservation of a floating sculpture from 1961 made from glass fibre-reinforced polyester resin

    NARCIS (Netherlands)

    Beerkens, L.; Stigter, S.; van Oosten, T.; van Keulen, H.; Keneghan, B.; Egan, L.

    2008-01-01

    Marta Pan’s Sculpture flottante, Otterlo was commissioned by the Kröller-Müller Museum for a pond at the entrance of the new sculpture garden that opened in June 1961. The floating sculpture is made from glass fibre-reinforced polyester resin and is now coated with white paint layers. The top is

  18. Modelling of ultrasonic beam propagation from an array through transversely isotropic fibre reinforced composites using Multi Gaussian beams

    NARCIS (Netherlands)

    Anand, C.; Shroff, S.; Groves, R.M.; Benedictus, R.

    2017-01-01

    Ultrasonic arrays are used for non-destructive evaluation of structures for aerospace and other applications. With the increase in the usage of fibre-reinforced composites in aerospace structures, this evaluation becomes complex due to the effects of attenuation and reflection from the layer

  19. Electrical and Mechanical Properties of 3D-Printed Graphene-Reinforced Epoxy

    Science.gov (United States)

    Compton, Brett G.; Hmeidat, Nadim S.; Pack, Robert C.; Heres, Maximilian F.; Sangoro, Joshua R.

    2018-03-01

    Recent developments in additive manufacturing have demonstrated the potential for thermoset polymer feedstock materials to achieve high strength, stiffness, and functionality through incorporation of structural and functional filler materials. In this work, graphene was investigated as a potential filler material to provide rheological properties necessary for direct-write three-dimensional (3D) printing and electrostatic discharge properties to the printed component. The rheological properties of epoxy/graphene mixtures were characterized, and printable epoxy/graphene inks formulated. Sheet resistance values for printed epoxy/graphene composites ranged from 0.67 × 102 Ω/sq to 8.2 × 103 Ω/sq. The flexural strength of printed epoxy/graphene composites was comparable to that of cast neat epoxy ( 80 MPa), suggesting great potential for these new materials in multifunctional 3D-printed devices.

  20. Electrical and Mechanical Properties of 3D-Printed Graphene-Reinforced Epoxy

    Science.gov (United States)

    Compton, Brett G.; Hmeidat, Nadim S.; Pack, Robert C.; Heres, Maximilian F.; Sangoro, Joshua R.

    2017-12-01

    Recent developments in additive manufacturing have demonstrated the potential for thermoset polymer feedstock materials to achieve high strength, stiffness, and functionality through incorporation of structural and functional filler materials. In this work, graphene was investigated as a potential filler material to provide rheological properties necessary for direct-write three-dimensional (3D) printing and electrostatic discharge properties to the printed component. The rheological properties of epoxy/graphene mixtures were characterized, and printable epoxy/graphene inks formulated. Sheet resistance values for printed epoxy/graphene composites ranged from 0.67 × 102 Ω/sq to 8.2 × 103 Ω/sq. The flexural strength of printed epoxy/graphene composites was comparable to that of cast neat epoxy ( 80 MPa), suggesting great potential for these new materials in multifunctional 3D-printed devices.