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Sample records for carbon fibre reinforced

  1. Multiwalled carbon nanotube reinforced biomimetic bundled gel fibres.

    Science.gov (United States)

    Kim, Young-Jin; Yamamoto, Seiichiro; Takahashi, Haruko; Sasaki, Naruo; Matsunaga, Yukiko T

    2016-08-19

    This work describes the fabrication and characterization of hydroxypropyl cellulose (HPC)-based biomimetic bundled gel fibres. The bundled gel fibres were reinforced with multiwalled carbon nanotubes (MWCNTs). A phase-separated aqueous solution with MWCNT and HPC was transformed into a bundled fibrous structure after being injected into a co-flow microfluidic device and applying the sheath flow. The resulting MWCNT-bundled gel fibres consist of multiple parallel microfibres. The mechanical and electrical properties of MWCNT-bundled gel fibres were improved and their potential for tissue engineering applications as a cell scaffold was demonstrated. PMID:27200527

  2. Advanced thermoplastic carbon fibre reinforced pultruded composites

    OpenAIRE

    Novo, P. J.; Silva, J F; Nunes, J. P.; MARQUES, A. T.

    2014-01-01

    The aim of this work is to optimize the production of new continuous carbon fibers reinforced thermoplastic matrix pre-impregnated materials (towpregs) continuously processed by dry deposition of polymer powders in a new equipment developed by the Institute for Polymers and Composites (IPC). The processing of the produced towpregs by pultrusion, in a developed prototype equipment existing in the Engineering School of the Polytechnic Institute of Porto (ISEP), was also optimized. Two differ...

  3. Electron beam processing of carbon fibre reinforced braided composites

    International Nuclear Information System (INIS)

    The possibility of producing a new type carbon fibre reinforced composite profile has been examined by applying braiding, a well-known process of textile technology. Pipe and hollow profile composite products can be manufactured this way by applying Electron Beam curing. The fabric-like braided reinforcing structure was manufactured out of Hungarian-made carbon fibre roving of 48,000 elementary fibres. The mutual irradiation of the system impregnated with epoxy-acrylate oligomer by 8 MeV EB resulted in better mechanical properties then conventional chemical curing. Owing to its low density and high specific strength this new composite product can possibly be applied in dynamically loaded structures e.g. in the automotive industry

  4. Low temperature properties of carbon fibre reinforced epoxide resins

    International Nuclear Information System (INIS)

    The material properties of carbon fibre reinforced epoxide resins are studied for applications at room temperature, as well as the high ratio of strength and stiffness to specific weight in structures. The test equipment, the specimens and the manufacturing procedures are described. Test equipment for low temperatures are illustrated in photos and charts. Results of mechanical and thermal tests are given and an investigation on lugs for a cryogenic tank for space application is proposed. Conclusions include the fact that most mechanical properties of unidirectional carbon fibre reinforced composites show higher values at low temperatures. Results of fatigue tests with glass-, carbon- and aramid compositions (Lugs) show a remarkable increase in fatigue life at low temperatures relative to room temperature

  5. Effects of fibre content on mechanical properties and fracture behaviour of short carbon fibre reinforced geopolymer matrix composites

    Indian Academy of Sciences (India)

    Tiesong Lin; Dechang Jia; Meirong Wang; Peigang He; Defu Liang

    2009-02-01

    Geopolymer matrix composites reinforced with different volume fractions of short carbon fibres (Cf/geopolymer composites) were prepared and the mechanical properties, fracture behaviour and microstructure of as-prepared composites were studied and correlated with fibre content. The results show that short carbon fibres have a great strengthening and toughening effect at low volume percentages of fibres (3.5 and 4.5 vol.%). With the increase of fibre content, the strengthening and toughening effect of short carbon fibres reduce, possibly due to fibre damage, formation of high shear stresses at intersect between fibres and strong interface cohesion of fibre/matrix under higher forming pressure. The property improvements are primarily based on the network structure of short carbon fibre preform and the predominant strengthening and toughening mechanisms are attributed to the apparent fibre bridging and pulling-out effect.

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

    International Nuclear Information System (INIS)

    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

  7. Fibre reinforced polymer nanocomposites

    NARCIS (Netherlands)

    Vlasveld, D.P.N.

    2005-01-01

    In this thesis the results are described of the research on a combination of two types of composites: thermoplastic nanocomposites and continuous fibre composites. In this three-phase composite the main reinforcing phase are continuous glass or carbon fibres, and the matrix consists of a polyamide 6

  8. 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

  9. Fibre reinforced polymer nanocomposites

    OpenAIRE

    Vlasveld, D.P.N.

    2005-01-01

    In this thesis the results are described of the research on a combination of two types of composites: thermoplastic nanocomposites and continuous fibre composites. In this three-phase composite the main reinforcing phase are continuous glass or carbon fibres, and the matrix consists of a polyamide 6 / layered silicate nanocomposite. To be able to produce and understand this new type of thermoplastic composite, the properties of the nanocomposite matrix materials have been investigated, follow...

  10. Development of textile-reinforced carbon fibre aluminium composites manufactured with gas pressure infiltration methods

    OpenAIRE

    W. Hufenbach; Gude, M.; A. Czulak; J. Śleziona; A. Dolata-Grosz; M. Dyzia

    2009-01-01

    Purpose: The aim of his paper is to show potential of textile-reinforced carbon fibre aluminium composite with advantage of the lightweight construction of structural components subjected to thermo-mechanical stress.Design/methodology/approach: The manufacture of specimens of the carbon fibre-reinforced aluminium was realised with the aid of an advanced differential gas pressure infiltration technique, which was developed at ILK, TU Dresden.Findings: The gas pressure infiltration technology e...

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

    International Nuclear Information System (INIS)

    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)

  12. Recycling of carbon fibre reinforced composites using water in subcritical conditions

    International Nuclear Information System (INIS)

    In this paper, a method of chemical recycling of thermosetting epoxy composite was discussed. Water was used to be reaction medium and the decomposition of carbon fibre reinforced epoxy composites was studied. Experiments were devised in order to identify the significant process parameters that affect fibre reinforced composite recovery potential including temperature, time, catalyst, feedstock, and pressure. Experiments were performed in a batch-type reactor without stirring. Under the condition that the temperature was 260 deg. C and the ratio of resin and water was 1:5 g/mL, the decomposition rate could reach 100 wt.% and the carbon fibres were obtained. The results from the Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM) measurements showed that the fibres were clean and no cracks or defects were found. The average tensile strength of the reclaimed fibres was about 98.2% than that of the virgin fibres.

  13. Deflection analysis of reinforced concrete beams strengthened with carbon fibre reinforced polymer under long-term load action

    Institute of Scientific and Technical Information of China (English)

    Mykolas DAUGEVI(C)IUS; Juozas VALIVONIS; Gediminas MAR(C)IUKAITIS

    2012-01-01

    This paper presents the results of an experimental research on reinforced concrete beams strengthened with an external carbon fibre reinforced polymer (CFRP) layer under long-term load action that lasted for 330 d.We describe the characteristics of deflection development of the beams strengthened with different additional anchorages of the external carbon fibre composite layer during the period of interest.The conducted experiments showed that the additional anchorage influences the slip of the extemal layer with respect to the strengthened element.Thus,concrete and carbon fibre composite interface stiffness decreases with a long-term load action.Therefore,the proposed method of analysis based on the built-up-bars theory can be used to estimate concrete and carbon fibre composite interface stiffness in the case of long-term load.

  14. 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

  15. 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.

  16. Processing, structure and flexural strength of CNT and carbon fibre reinforced, epoxy-matrix hybrid composite

    Indian Academy of Sciences (India)

    K Chandra Shekar; M Sai Priya; P K Subramanian; Anil Kumar; B Anjaneya Prasad; N Eswara Prasad

    2014-05-01

    Advanced materials such as continuous fibre-reinforced polymer matrix composites offer significant enhancements in variety of properties, as compared to their bulk, monolithic counterparts. These properties include primarily the tensile stress, flexural stress and fracture parameters. However, till date, there are hardly any scientific studies reported on carbon fibre (Cf) and carbon nanotube (CNT) reinforced hybrid epoxy matrix composites (unidirectional). The present work is an attempt to bring out the flexural strength properties along with a detailed investigation in the synthesis of reinforced hybrid composite. In this present study, the importance of alignment of fibre is comprehensively evaluated and reported. The results obtained are discussed in terms of material characteristics, microstructure and mode of failure under flexural (3-point bend) loading. The study reveals the material exhibiting exceptionally high strength values and declaring itself as a material with high strength to weight ratio when compared to other competing polymer matrix composites (PMCs); as a novel structural material for aeronautical and aerospace applications.

  17. Electron beam processing of carbon fibre reinforced braided composites beams

    International Nuclear Information System (INIS)

    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

  18. Low temperature properties of carbon fibre reinforced expoxide resins

    International Nuclear Information System (INIS)

    This chapter reports on the testing of two epoxide resin systems: the semiflexible epoxy CY221/HY979 and the rigid epoxy LY556/HY917. Discusses selection of materials and main properties; evaluation and stress analysis of different specimens; sample manufacture; test equipment for low temperatures; results of mechanical and thermal tests; and investigation on lugs for a cryogenic tank for space application. Finds that most mechanical properties of unidirectional Carbon Fiber Reinforced Composites show higher values at low temperatures. Concludes that interlaminar shear strength appears to reach a maximum at 218K; and that fatigue tests with glass-, carbon- and aramid composites (Lugs) show a remarkable increase in fatigue life at low temperatures relative to room temperature

  19. Investigations on d.c. conductivity behaviour of milled carbon fibre reinforced epoxy graded composites

    Indian Academy of Sciences (India)

    Navin Chand; Archana Nigrawal

    2008-08-01

    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 on the graded composites by using an Electrometer in the temperature range from 26°C to 150°C. D.C. conductivity increases with the increase of distance in the direction of centrifugal force, which shows the formation of graded structure with the composites. D.C. conductivity increases on increase of milled carbon fibre content from 0.45 to 1.66 vol.%. At 50°C, d.c. conductivity values were 1.85 × 10-11, 1.08 × 10-11 and 2.16 × 10-12 for samples 1, 2 and 3, respectively. The activation energy values for different composite samples 1, 2 and 3 are 0.489, 0.565 and 0.654 eV, respectively which shows decrease in activation energy with increase of fibre content.

  20. Carbide formation in tungsten coatings on carbon-fibre reinforced carbon substrates

    International Nuclear Information System (INIS)

    Tungsten coatings with molybdenum interlayer deposited on carbon-fibre reinforced carbon (CFC) substrates were selected as the first wall material for the divertor in the Wall Project at Joint European Torus (similar to the International Thermonuclear Experimental Reactor). For such a layered structure, diffusion of carbon from the CFC substrate towards the Mo and W deposits is expected during the operation of the reactor. As both molybdenum and tungsten form stable carbides, brittle compounds may form at the interface, thus strongly affecting the thermomechanical performance of the coated tiles. For the purpose of prediction of the operation time of such coated tiles, carbon diffusion and carbide formation kinetics need to be determined. In the present study, W/Mo/CFC samples were subjected to heat treatment at 1470 K for various annealing times. The Focused Ion Beam technique was used for sample preparation for electron microscopy examinations. Transmission electron microscopy observations supported with diffraction pattern analyses revealed the both W2C and WC carbides in the W coating, as well as that of Mo2C carbide in the Mo layer. The results were used to estimate the kinetics of coatings degradation. - Highlights: ► Thin Mo/W layers system on carbon-fibre reinforced carbon divertor tile ► Heat treatment at 1470 K results in two tungsten carbide creation — W2C and WC ► The total tungsten carbide creation is limited by carbon diffusion ► WC carbide creation is limited by W2C–WC reaction rate

  1. Assessment of adhesive setting time in reinforced concrete beams strengthened with carbon fibre reinforced polymer laminates

    International Nuclear Information System (INIS)

    Highlights: ► This study investigated the effect of adhesive setting time on the modal parameters. ► Modal parameters recommend the 18th day as the maturity age of the adhesive. ► Static data recommend 7th day as the maturity age of the adhesive. ► Setting time affects the modal parameters as tool for assessment repaired structures. ► Carrying the modal parameters after 1st day results in 55% loss of the actual improvement. -- Abstract: The strengthened effectiveness and the performance capacity of repaired Reinforced Concrete (RC) structures with Carbon Fibre Reinforced Polymer (CFRP) sheets is dependent on the properties of the adhesive interface layer. Adhesive material requires a specific setting time to achieve the maximum design capacity. Adhesive producer provides technical data which demonstrates the increase with time of the capacity, up to the maximum. The aim of this study is to investigate the effect of the adhesive setting time on the modal parameters as an indication of the effectiveness of CFRP on repaired RC beams. Firstly, datum modal parameters were determined on the undamaged beam and subsequently the parameters were obtained when damaged was induced on the RC beam by application of load until the appearance of the first crack. Finally, the RC beam is repaired with externally bonded CFRP sheets, and modal parameters are once again applied after 0.5, 1, 2, 3, 5, 8, 11, 15 and 18 days. The comparison is made with the data based on half day results in order to monitor the change in the modal parameters corresponding to the adhesive setting time. The modal parameters where used as indicators for the effectiveness of CFRP are affected by the adhesive time as shown in this study. Results are compared with the adhesive technical data provided by the adhesive producer.

  2. Statics and dynamics of carbon fibre reinforcement composites on steel orthotropic decks

    Czech Academy of Sciences Publication Activity Database

    Frýba, Ladislav; Pirner, Miroš; Urushadze, Shota

    Southampton : WIT Press, 2009 - (Carlomagno, G.; Brebbia, C.), s. 117-123 ISBN 978-1-84564-187-0. [International Conference Computational Methods and Experimental Measurements /14./. Algarve (PT), 10.06.2009-12.06.2009] Grant ostatní: GA ČR(CZ) GA103/08/1340 Institutional research plan: CEZ:AV0Z20710524 Keywords : carbon fibre reinforced composite * orthotropic deck * fatigue life * dynamic load * crack propagation Subject RIV: JM - Building Engineering

  3. Toughening of carbon fibre reinforced polymer composites with rubber nanoparticles for advanced industrial applications

    OpenAIRE

    N. G. Ozdemir; Zhang, T.; I. Aspin; Scarpa, F.; Hadavinia, H.; Song, Y.

    2016-01-01

    This study investigates the effects of nano carboxylic acrylonitrile butadiene rubber (CNBR-NP) and nano acrylonitrile butadiene rubber (NBR-NP) on the interlaminar shear strength and fracture toughness of carbon fibre reinforced polymer composites (CFRP) with dicyandiamide-cured epoxy matrix. The results show that nano-size dispersion of rubber significantly improved the Mode I delamination fracture toughness (GIC) of the CFRP by 250% and its Mode II delamination fracture toughness (GIIC) by...

  4. Predicting the mechanical behaviour of carbon fibre reinforced silicon carbide with interlaminar manufacturing defects

    OpenAIRE

    Hofmann Severin; Koch Dietmar

    2015-01-01

    A finite element approach based on experimental material data is presented in order to compute the mechanical reliability of carbon fibre reinforced silicon carbide, C/C-SiC, taking interlaminar manufacturing defects into account. The approach is evaluated on sample scale by modelling the flexural behaviour of C/C-SiC samples containing delaminations after liquid silicon infiltration (LSI) processing. The non-destructive evaluation methods, determination of fracture mechanical input data and ...

  5. Fatigue behaviour of carbon fibre reinforcement composites on steel orthotropic decks

    Czech Academy of Sciences Publication Activity Database

    Urushadze, Shota; Frýba, Ladislav; Pirner, Miroš

    Kuala Lumpur : ASEM, 2010 - (Daut Mohamad, D.; Ahmad, D.), s. 102-102 ISBN N. [International Conference on Experimental Mechanics 2010- ICEM 2010. Kuala Lumpur (MY), 29.11.2010-1.12.2010] R&D Projects: GA ČR(CZ) GA103/08/1340 Institutional research plan: CEZ:AV0Z20710524 Keywords : fatigue * carbon fibre reinforced composites (CFRC) * orthotropic decks. Subject RIV: JM - Building Engineering

  6. Thermo-mechanical correlations to erosion performance of short carbon fibre reinforced vinyl ester resin composites

    International Nuclear Information System (INIS)

    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 oC. 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 oC. The erosion rates (Er) of these composites are evaluated at different impingement angles (30-90o), 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.

  7. Fibre-reinforced thermoplastics

    OpenAIRE

    Røsand, Vegar Rydén

    2011-01-01

    This thesis presents experimental tests of fibre-reinforced polypropylene, as well as calibration of material coefficients and simulations of experimental tests. The focus is on exploring the dependence on loading direction to fibre direction and rate of strain, and on validation of the material coefficient.First the material and the experimental procedure is presented together with the results from the tests.Uniaxial tension tests, cyclic loading-unloading tests and components tests is perfo...

  8. Impact fatigue behaviour of carbon fibre-reinforced vinylester resin composites

    Indian Academy of Sciences (India)

    Rita Roy; B K Sarkar; A K Rana; N R Bose

    2001-02-01

    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 specially designed and constructed for the purpose. A well-defined impact fatigue behaviour (S–N type curve) curve has been demonstrated. It showed a plateau region of 10–102 cycles immediately below the single cycle impact strength, followed by progressive endurance with decreasing impact loads, culminating in an endurance limit at about 71% and 85% of the single impact strength for DHMS-48 and VLMS-48, respectively. Analysis of the fractured surfaces revealed primary debonding, fibre breakage and pull-out at the tensile zone of the samples and a shear mode of fracture with breakage of fibre bundles at the compressive zone of the samples. The occurrence of a few major macrocracks in the matrix with fibre breakage at the high load–low endurance region and development of multiple microcracks in the matrix, coalescing and fibre breakage at the low-load–high endurance region have been inferred to explain the fatigue behaviour of the composites examined.

  9. 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.

  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

    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...

  11. A Lamb waves based statistical approach to structural health monitoring of carbon fibre reinforced polymer composites.

    Science.gov (United States)

    Carboni, Michele; Gianneo, Andrea; Giglio, Marco

    2015-07-01

    This research investigates a Lamb-wave based structural health monitoring approach matching an out-of-phase actuation of a pair of piezoceramic transducers at low frequency. The target is a typical quasi-isotropic carbon fibre reinforced polymer aeronautical laminate subjected to artificial, via Teflon patches, and natural, via suitable low velocity drop weight impact tests, delaminations. The performance and main influencing factors of such an approach are studied through a Design of Experiment statistical method, considering both Pulse Echo and Pitch Catch configurations of PZT sensors. Results show that some factors and their interactions can effectively influence the detection of a delamination-like damage. PMID:25746761

  12. Toughening of carbon fibre reinforced polymer composites with rubber nanoparticles for advanced industrial applications

    Directory of Open Access Journals (Sweden)

    N. G. Ozdemir

    2016-05-01

    Full Text Available This study investigates the effects of nano carboxylic acrylonitrile butadiene rubber (CNBR-NP and nano acrylonitrile butadiene rubber (NBR-NP on the interlaminar shear strength and fracture toughness of carbon fibre reinforced polymer composites (CFRP with dicyandiamide-cured epoxy matrix. The results show that nano-size dispersion of rubber significantly improved the Mode I delamination fracture toughness (GIC of the CFRP by 250% and its Mode II delamination fracture toughness (GIIC by 80% with the addition of 20 phr of CNBR-NP. For the NBR-NP system, the GIC and GIIC delamination fracture toughness of the CFRP were increased by 200 and 80% respectively with the addition of 20 phr (parts per hundred rubber of nano rubber to the matrix. Scanning electron microscopy (SEM images of the fracture surface revealed that the toughening was mainly achieved by debonding of the nano rubber, crack path deflection and fibre bridging.

  13. A combined corrosion protection system for reinforced concrete structures using a carbon fibre mesh

    Energy Technology Data Exchange (ETDEWEB)

    Bruns, M.; Raupach, M. [Institut fuer Bauforschung der RWTH Aachen, IBAC, Institute of Building Materials Research of the Technical University of Aachen, Schinkelstrasse 3 Aachen (Germany)

    2004-07-01

    Cathodic Protection (CP) has become a world-wide used method to protect reinforced concrete structures against reinforcement corrosion. Another method to stop or reduce reinforcement corrosion, at least in case of lower chloride contents is the reduction of the water content of the concrete by applying sealing coatings on the concrete surface. At the Institute of Building Materials Research of Aachen University (IBAC) actually a surface protection system is investigated based on the combination of both methods mentioned above. The idea is to protect the reinforcement within the first years after system installation by cathodic protection until the water content of the concrete has decreased to a level due to the surface coating where the corrosion rate of the reinforcement is uncritical and does not lead to any damage. The system investigated, consists of a carbon fibre net embedded in a special mortar layer as impressed current anode for cathodic protection, covered by a 'dense' cement based polymer modified surface coating. In order to investigate the system, it has been installed on a test area on the weathered upper deck of a parking garage in Aachen, Germany. To investigate the effectiveness regarding the reduction of the water content of the concrete the test area was equipped with so called Multiring-Electrodes (MRE) for depth depended measurement of the concrete resistivity. Reference electrodes for potential and depolarization measurements as well a device for automatic measurement of the protection current were installed to investigate the effectiveness of the impressed current cathodic protection. Additionally 3 re bars were embedded into the concrete of the test area using mortar containing 1, 2 or 3 M.-% chloride by weight of cement respectively, to investigate the influence of the chloride content. First results of the MRE-measurements showing already within the first months after system installation a distinct drying of the concrete cover

  14. Prediction of failure in notched carbon-fibre-reinforced-polymer laminates under multi-axial loading.

    Science.gov (United States)

    Tan, J L Y; Deshpande, V S; Fleck, N A

    2016-07-13

    A damage-based finite-element model is used to predict the fracture behaviour of centre-notched quasi-isotropic carbon-fibre-reinforced-polymer laminates under multi-axial loading. Damage within each ply is associated with fibre tension, fibre compression, matrix tension and matrix compression. Inter-ply delamination is modelled by cohesive interfaces using a traction-separation law. Failure envelopes for a notch and a circular hole are predicted for in-plane multi-axial loading and are in good agreement with the observed failure envelopes from a parallel experimental study. The ply-by-ply (and inter-ply) damage evolution and the critical mechanisms of ultimate failure also agree with the observed damage evolution. It is demonstrated that accurate predictions of notched compressive strength are obtained upon employing the band broadening stress for microbuckling, highlighting the importance of this damage mode in compression. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. PMID:27242302

  15. Resistance welding of carbon fibre reinforced polyetheretherketone composites using metal mesh and PEI film

    Institute of Scientific and Technical Information of China (English)

    闫久春; 王晓林; 秦明; 赵新英; 杨士勤

    2004-01-01

    Weldability of polyetheretherketone(PEEK) with polyetherimide(PEI) is tested. And carbon fiber reinforced PEEK laminates are resistance welded using stainless steel mesh heating element. The effects of the welding time and welding pressure on the lap shear strength of joints are investigated. Results show that PEEK can heal with PEI well in welding condition and the lap shear strength of PEEK/CF(carbon fibre) joint increases linearly with welding time, but reaches a maximum value when welding pressure ranging from 0.3MPa to 0.5MPa with constant welding time. The fracture characteristics of surface are analyzed by SEM techniques, and four types of fracture modes of lap shear joints are suggested.

  16. Nylon 6,6 electrospun fibres reinforced by amino functionalised 1D and 2D carbon

    International Nuclear Information System (INIS)

    Nylon 6,6 electrospun nanocomposites were prepared and reinforced with 0.1, 0.5 and 1wt.% of 1D and 2D carbon. Both carbon nanotubes and graphene were functionalised with amino groups (f-CNT and f-Ge respectively). The morphology and graphitization changes of carbon nanomaterials were evaluated by transmission electron microscopy (TEM) and Raman spectroscopy; functional groups of modified nanomaterials was analysed by infrared spectroscopy. The mechanical response and the crystallinity of the fibres were measured by dynamical mechanical analysis, differential scanning calorimetry and wide angle x-ray diffraction. The morphology and dispersion of the nanomaterials in the nanofibres was studied by scanning electron microscopy and TEM. The storage modulus was improved by 118% for f-CNT and 116% for f-Ge. The mechanical response of the nanocomposites exhibited different behaviour upon loading of 1D and 2D carbon. This trend is consistent with the crystallinity of the nanofibres. This study showed f-CNT resulted in better mechanical properties at the lowest loading. On the other hand f-Ge showed improved reinforcing effect by increasing the filler loading. The two-dimensional structure of graphene was an important factor for the higher crystallinity in the electrospun nanofibres.

  17. Repeated self-healing of microvascular carbon fibre reinforced polymer composites

    International Nuclear Information System (INIS)

    A self-healing, high performance, carbon fibre reinforced polymer (CFRP) composite is demonstrated by embedding a Lewis-acid catalytic curing agent within a laminate, manufactured using out of autoclave (OOA) composite manufacturing methods. Two configurations of healing agent delivery, pre-mixed and autonomous mixing, are investigated via injection of a healing agent through bio-inspired microvascular channels exposed on Mode I fractured crack planes. Healing is effected when an epoxy resin-solvent healing agent mixture reaches the boundary of embedded solid-state scandium(III) triflate (Sc(OTf)3) catalyst, located on the crack plane, to initiate the ring-opening polymerisation (ROP) of epoxides. Tailored self-healing agents confer high healing efficiency values after multiple healing cycles (69–108%) to successfully mitigate against crack propagation within the composite microstructure. (paper)

  18. Cutting forces in ultrasonically assisted drilling of carbon fibre-reinforced plastics

    Science.gov (United States)

    Makhdum, Farrukh; Jennings, Luke T.; Roy, Anish; Silberschmidt, Vadim V.

    2012-08-01

    Ultrasonically assisted drilling (UAD) is a non-traditional hybrid machining process, which combines features of conventional drilling and vibratory machining techniques to obtain remarkable improvements in machinability of advanced materials. The experiments are conducted on commercially available samples of a carbon fibre-reinforced plastic (CFRP) at a feed rate of 16 mm/min. In this study, a thrust force reduction in excess of 60% is observed in UAD when compared to conventional drilling (CD). Lower delamination was observed when compared to CD techniques. Optical microscopy revealed that the material is removed as a continuous chip in UAD whereas in case of CD we observe powdered dust. Light and scanning electron microscopy of CFRP chips obtained in drilling elucidate fundamental differences in the underlying machining processes in UAD of CFRP.

  19. Cutting forces in ultrasonically assisted drilling of carbon fibre-reinforced plastics

    International Nuclear Information System (INIS)

    Ultrasonically assisted drilling (UAD) is a non-traditional hybrid machining process, which combines features of conventional drilling and vibratory machining techniques to obtain remarkable improvements in machinability of advanced materials. The experiments are conducted on commercially available samples of a carbon fibre-reinforced plastic (CFRP) at a feed rate of 16 mm/min. In this study, a thrust force reduction in excess of 60% is observed in UAD when compared to conventional drilling (CD). Lower delamination was observed when compared to CD techniques. Optical microscopy revealed that the material is removed as a continuous chip in UAD whereas in case of CD we observe powdered dust. Light and scanning electron microscopy of CFRP chips obtained in drilling elucidate fundamental differences in the underlying machining processes in UAD of CFRP.

  20. Predicting the mechanical behaviour of carbon fibre reinforced silicon carbide with interlaminar manufacturing defects

    Directory of Open Access Journals (Sweden)

    Hofmann Severin

    2015-01-01

    Full Text Available A finite element approach based on experimental material data is presented in order to compute the mechanical reliability of carbon fibre reinforced silicon carbide, C/C-SiC, taking interlaminar manufacturing defects into account. The approach is evaluated on sample scale by modelling the flexural behaviour of C/C-SiC samples containing delaminations after liquid silicon infiltration (LSI processing. The non-destructive evaluation methods, determination of fracture mechanical input data and the numerical cohesive zone approach are described. The numerical predictions of flexural stiffness and strength of samples with and without interlaminar defects were validated by bending tests of the respective samples. The difference between tensile and bending behaviour is explained by FE modelling for this group of CMC materials.

  1. Strengthening of steel–concrete composite girders using carbon fibre reinforced polymer (CFRP) plates

    Indian Academy of Sciences (India)

    S M Mosavi; A Sadeghi Nik

    2015-02-01

    Applying composites in order to strengthen and renew the infrastructures has globally been accepted. Traditional methods to strengthen the out-of-standard structures are costly, time consuming and requires a lot of labour. Today, new techniques are hired using light and strong substances which also resist against corrosion, known as Carbon Fibre Reinforced Polymer (CFRP) plates. Regarding the high tensile strength and proper module of elasticity, CFRP plates are considered as a suitable alternative to strengthen girders. The behaviour of steel–concrete composite girders being statically loaded and strengthened by CFRP plates in this study. The CFRP plates used in this study have been stuck, with epoxy adhesive, under the tensile sections of three steel girders. The results accompanied with analytical study of moment–curvature and numerical analysis done with ANSYS, show that CFRP plates with epoxy adhesive increases the ultimate loading capacity of steel–concrete composite girder. Plastic stiffness of the girders was also increased.

  2. High-power picosecond laser drilling/machining of carbon fibre-reinforced polymer (CFRP) composites

    Science.gov (United States)

    Salama, A.; Li, L.; Mativenga, P.; Sabli, A.

    2016-02-01

    The large differences in physical and thermal properties of the carbon fibre-reinforced polymer (CFRP) composite constituents make laser machining of this material challenging. An extended heat-affected zone (HAZ) often occurs. The availability of ultrashort laser pulse sources such as picosecond lasers makes it possible to improve the laser machining quality of these materials. This paper reports an investigation on the drilling and machining of CFRP composites using a state-of-the-art 400 W picosecond laser system. Small HAZs (drilled on sample of 6 mm thickness, whereas no HAZ was seen below the top surface on the cut surfaces. Multiple ring material removal strategy was used. Furthermore, the effect of laser processing parameters such as laser power, scanning speed and repetition rate on HAZ sizes and ablation depth was investigated.

  3. Exposure Assessment of Particulate Matter from Abrasive Treatment of Carbon and Glass Fibre-Reinforced Epoxy-Composites

    DEFF Research Database (Denmark)

    Jensen, Alexander C. Ø.; Levin, Marcus; Koivisto, Antti J.;

    2015-01-01

    The use of composites is ever increasing due to their important structural and chemical features. The composite component production often involves high energy grinding and sanding processes to which emissions workers are potentially exposed. In this study we investigated the machining of carbon...... and glass fibre-reinforced epoxy composite materials at two facilities. We measured particle number concentrations and size distributions of the released material in near field and far field during sanding of glass-and carbon fibre-reinforced composites. We assessed the means of reducing exposure...... 1.1% and 14.1% when comparing with a careful working style. Investigating the effect of the local exhaust ventilation showed that a maximum flow rate caused removal of close to 100% of particles from the working zone. A 28% reduction in the flow rate reduced particle removal efficiency more than 50...

  4. Interlaminar fracture micro-mechanisms in toughened carbon fibre reinforced plastics investigated via synchrotron radiation computed tomography and laminography

    OpenAIRE

    Borstnar, G.; M. N. Mavrogordato; Helfen, L.; Sinclair, I.; Spearing, S.M.

    2015-01-01

    Synchrotron Radiation Computed Tomography (SRCT) and Synchrotron Radiation Computed Laminography (SRCL) permit 3D non-destructive evaluation of fracture micro-mechanisms at high spatial resolutions. Two types of particle-toughened Carbon Fibre Reinforced Polymer (CFRP) composites were loaded to allow crack growth in Modes I and II to be isolated and observed in standard and non-standard specimen geometries. Both materials failed in complex and distinct failure modes, showing that interlaminar...

  5. Hidden defect identification in carbon fibre reinforced polymer plates using magnetic induction tomography

    International Nuclear Information System (INIS)

    Carbon fibre reinforced polymer (CFRP) materials pose new challenges to the non-destructive evaluation (NDE) techniques. This study addresses the issue of large defect identification in CFRP plates using electromagnetic measurements. A dual plane magnetic induction tomography (MIT) technique is proposed as a method for damage localization in composite parts, where two arrays of planar sensors are utilized to measure the changes in induced voltages due to the changes in electrical conductivity properties. This geometry meets the requirements of damage inspection in plate structures and thus makes the imaging process feasible. The electrical voltage measurements are used as input to inversely map the spatial resolution of the samples in the region of interest. The stability and detectability of the dual plane system is examined using small metallic cubes. Both individual and multiple instances of damage embedded in CFRP samples are created as a representation of the possible manufacturing defects. Experimental study shows that the presence of damage can be identified in both cases using the dual plane MIT system. With advanced sensing design, rapid data collection unit and improvement in resolution, MIT could become a rapid NDE technique for the integrity inspection of composite structures. (paper)

  6. Average Frequency – RA Value for Reinforced Concrete Beam Strengthened with Carbon Fibre Sheet

    Directory of Open Access Journals (Sweden)

    Mohamad M. Z.

    2016-01-01

    Full Text Available Acoustic Emission (AE is one of the tools that can be used to detect the crack and to classify the type of the crack of reinforced concrete (RC structure. Dislocation or movement of the material inside the RC may release the transient elastic wave. In this situation, AE plays important role whereby it can be used to capture the transient elastic wave and convert it into AE parameters such as amplitude, count, rise time and duration. Certain parameter can be used directly to evaluate the crack behavior. But in certain cases, the AE parameter needs to add and calculate by using related formula in order to observe the behavior of the crack. Using analysis of average frequency and RA value, the crack can be classified into tensile or shear cracks. In this study, seven phases of increasing static load were used to observe the crack behavior. The beams were tested in two conditions. For the first condition, the beams were tested in original stated without strengthened with carbon fibre sheet (CFS at the bottom of the beam or called as tension part of the beam. For the second condition, the beams were strengthened with CFS at the tension part of the beam. It was found that, beam wrapped with CFS enhanced the strength of the beams in term of maximum ultimate load. Based on the relationship between average frequency (AF and RA value, the cracks of the beams can be classified.

  7. Galvanic corrosion behaviour of carbon fibre reinforced polymer/magnesium alloys coupling

    International Nuclear Information System (INIS)

    Highlights: • The coupling of T300/648 and Mg–Li shows a large driving force for galvanic corrosion. • The galvanic activity of T300/648 coupled to Mg–Li increases with the increase of Li. • The duration of the current instability in T300/648 and magnesium coupling increases with the increase of Li. • The micro-arc oxidation film with double-layer exhibit good inhibiting effect on galvanic corrosion. - Abstract: The galvanic corrosion behaviour of carbon fibre reinforced polymer (CFRP, T300/648) in contact with different magnesium alloys (AZ31, LZ91 and LZ141) in a sodium chloride solution and the influence of micro-arc oxidation (MAO) film on the corrosion behaviour of CFRP/magnesium alloys coupling were investigated using the electrochemical method. The results showed that the galvanic activity of CFRP/magnesium alloys coupling increased with the increase of lithium concentrations. The duration of the inhibitory effect of MAO film on the corrosion of CFRP/Mg–Li coupling is longer than that of CFRP/Mg–Al coupling due to its double-layer structure

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

    International Nuclear Information System (INIS)

    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

  9. 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.

  10. Forming of UD fibre reinforced thermoplastics

    OpenAIRE

    Haanappel, S.P.

    2013-01-01

    Composite materials are a serious competitor for lightweight metals used in the aerospace and automotive industry. Uni-directional (UD) carbon fibre reinforced thermoplastics are favoured due to their high specific strength and stiffness, but also their good toughness, impact and chemical resistance properties. By heating UD reinforced thermoplastic laminates sufficiently above the melting point of the polymer, these can be stamp-formed to relatively complex geometries. The product is release...

  11. Forming of UD fibre reinforced thermoplastics

    NARCIS (Netherlands)

    Haanappel, S.P.

    2013-01-01

    Composite materials are a serious competitor for lightweight metals used in the aerospace and automotive industry. Uni-directional (UD) carbon fibre reinforced thermoplastics are favoured due to their high specific strength and stiffness, but also their good toughness, impact and chemical resistance

  12. Slender reinforced concrete columns strengthened with fibre reinforced polymers

    Science.gov (United States)

    Gajdošová, K.; Bilčík, J.

    2011-06-01

    The requirement for a long life with relatively low maintenance costs relates to the use of building structures. Even though the structure is correctly designed, constructed and maintained, the need for extensions of its lifetime can appear. The preservation of the original structure with a higher level of resistance or reliability is enabled by strengthening. Conventional materials are replaced by progressive composites - mainly carbon fibre reinforced polymers (CFRP). They are used for strengthening reinforced concrete columns in two ways: added reinforcement in the form of CFRP strips in grooves or CFRP sheet confinement and eventually their combination. This paper presents the effect of the mentioned strengthening methods on slender reinforced concrete columns.

  13. SEISMIC PERFORMANCE OF A PRECAST REINFORCED CONCRETE WALL WITH CUT-OUT OPENING RETROFITTED USING CARBON FIBRE STRIPS

    Directory of Open Access Journals (Sweden)

    Fofiu M.

    2015-05-01

    Full Text Available The Precast Reinforced Concrete Wall Panel (PRCWP presented in this paper is part of an experimental study regarding the seismic performance of precast reinforced concrete wall panels, strengthening strategies and investigation on the weakening induced by modifying the opening in these elements due to architectural demands, change of function of buildings or other reasons. The element presented is 1:1.2 scale typical Reinforced Concrete Wall Panel with a window opening used in Romania, in which the opening was changed to a door opening due to comfort considerations. The specimen was subjected to cyclic loading with the lateral loads being applied in displacement control of 0.1% drift ratio. This simulates the shear behaviour of the element. After testing the unstrengthen element we proceed to retrofit it using Carbon Fibre Strips anchored with Carbon Fibre Mash. The purpose of the paper is to present the strengthening strategy and restore the initial load bearing capacity of the element or even increase it. The experimental results of strengthen and unstrengthen specimens will be presented.

  14. The mechanics of fibre-reinforced sand

    OpenAIRE

    Dos Santos, APS; Consoli, NC; Baudet, BA

    2010-01-01

    Fibres can be an effective means of reinforcing soils. This paper presents data from laboratory triaxial tests on quartzitic sand reinforced with polypropylene fibres. By keeping the studied composite consistent throughout the study (host sand and fibre characteristics kept constant), it has been possible to develop a framework of behaviour for the sand-fibre material, which provides a solid base for future research on fibre-reinforced soils. Data from previous work and from new tests have be...

  15. Natural Fibre-Reinforced Biofoams

    Directory of Open Access Journals (Sweden)

    Anne Bergeret

    2011-01-01

    Full Text Available Starches and polylactic acids (PLAs represent the main biobased and biodegradable polymers with potential industrial availability in the next decades for “bio” foams applications. This paper investigates the improvement of their morphology and properties through processing and materials parameters. Starch foams were obtained by melt extrusion in which water is used as blowing agent. The incorporation of natural fibres (hemp, cellulose, cotton linter, sugarcane, coconut in the starch foam induced a density reduction up to 33%, a decrease in water absorption, and an increase in mechanical properties according to the fibre content and nature. PLA foams were obtained through single-screw extrusion using of a chemical blowing agent that decomposed at the PLA melting temperature. A void content of 48% for PLA and 25% for cellulose fibre-reinforced PLA foams and an improvement in mechanical properties were achieved. The influence of a fibre surface treatment was investigated for both foams.

  16. Energy efficient microwave heating of carbon fibre reinforced plastic; Energieeffiziente Mikrowellentemperierung von kohlenstofffaserverstaerkten Duroplasten

    Energy Technology Data Exchange (ETDEWEB)

    Danilov, Maksim

    2013-07-01

    The polymerization of carbon fiber reinforced thermosetting composites (CFRP) is a dull process step with high energy requirements within the production chain. His improvement would affect the economic and ecological balance of the fiber reinforced materials in a positive way. One possible approach investigated here is tempering of raw materials in a microwave oven. In this work the material to be processed - a carbon fiber-reinforced plastic laminate - is being characterized in the microwave field through electromagnetic and thermal parameters. The relationship between its design parameters (fiber orientation and number of layers), the energy levels (reflection, absorption and transmittance) and the thermal process parameters (temperature gradient achievable) will be established. Afterwards, constructive options will be examined and evaluated which are suitable to install a low-loss (both by means of wave reflections and heat losses) industrial process.

  17. Compressive Strength of Fibre Reinforced Concrete

    OpenAIRE

    Jelušič, Matjaž

    2009-01-01

    The thesis features an analysis of the time development of compressive strength of fibre reinforced normal and high strength concrete. Concrete mixtures, taken from the doctoral dissertation of assistant Dr Drago Saje, were used as comparable mixtures to fibre reinforced concrete mixtures with different volume shares of fibres. Two types of steel fibres were used, both featuring the same characteristics but having different lengths (16 and 30 mm), as well as polypropylene fibres. The percenta...

  18. Strength Evaluation of Steel-Nylon Hybrid Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Maniram Kumar

    2014-07-01

    Full Text Available When fibres like steel, glass, polypropylene, nylon, carbon, aramid, polyester, jute, etc are mixed with concrete known as fibre reinforced concrete. To overcome the deficiencies of concrete; fibres are added to improve the performance of concrete. In this research hybrid reinforced concrete is made by using steel and nylon 6 fibres. The inclusion of both steel and nylon 6 fibres are used in order to combine the benefits of both fibers; structural improvements provided by steel fibers and the resistance to plastic shrinkage improvements provided by nylon fibers. So the aim of this project is to investigate the mechanical properties (compressive strength, flexure strength and split tensile strength of hybrid fiber reinforced concrete under compression, flexure & tension. The total volume of fibre was taken 0.75 % of total volume of concrete. In this experimental work, four different concrete mix proportions were casted with fibres and one mix without fibres. Four different mix combinations of steel- nylon 6 fibres were 100-00%, 75-25%, 50-50% and 25-75%. Superplasticizer was used in all mixes to make concrete more workable. The results shown that compressive, split tensile and flexural strength of hybrid fibre reinforced concrete increase by increasing quantity of steel and nylon 6 fibres. The increase in compressive and tensile strength due to incorporation of steel fibre is greater than that of using nylon fibre. For the nylon 6 fibres, adding more fibres into the concrete has a limited improvement on splitting tensile strength. Inclusion of nylon 6 fibres along with steel fibres results in considerable improvement in flexural strength as compared to solo steel fibre.

  19. Hydrofluoric–nitric–sulphuric-acid surface treatment of tungsten for carbon fibre-reinforced composite hybrids in space applications

    Energy Technology Data Exchange (ETDEWEB)

    Kanerva, M., E-mail: Mikko.Kanerva@aalto.fi [Aalto University, School of Engineering, Department of Applied Mechanics, P.O.B. 14300, FI-00076 Aalto (Finland); Johansson, L.-S.; Campbell, J.M. [Aalto University, School of Chemical Technology, Department of Forest Products Technology, P.O.B. 16300, FI-00076 Aalto (Finland); Revitzer, H. [Aalto University, School of Chemical Technology, Department of Chemistry, P.O.B. 16300, FI-00076 Aalto (Finland); Sarlin, E. [Tampere University of Technology, Department of Materials Science, P.O.B. 589, FI-33101 Tampere (Finland); Brander, T.; Saarela, O. [Aalto University, School of Engineering, Department of Applied Mechanics, P.O.B. 14300, FI-00076 Aalto (Finland)

    2015-02-15

    Highlights: • XPS and AFM analysis of the effect of hydrofluoric–nitric–sulphuric-acid on tungsten. • Dreiling's model established 54.4% thinning of WO{sub 3} due to 67 s treatment. • Strain energy release rate increased ≈8.4 J/m{sup 2} at the interface. • Failure loci analysis expressed the oxide and carbon fibre surfaces as weak points. - Abstract: Hybrid material systems, such as combinations of tungsten foils and carbon fibre-reinforced plastic (CFRP), are replacing metal alloy concepts in spacecraft enclosures. However, a good adhesion between the tungsten oxide scale and the epoxy resin used is required. Here, the effects of a hydrofluoric–nitric–sulphuric-acid (HFNS) treatment on tungsten oxides and subsequent adhesion to CFRP are analysed using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fracture testing. The work shows that HFNS treatment results in decreased oxygen content, over 50% thinner tungsten trioxide (WO{sub 3}) layer and increased nano-roughness on thin tungsten foils. Fracture testing established a 39% increase in the average critical strain for tungsten–CFRP specimens after HFNS treatment was carried out on tungsten. The effect of the oxide scale modification regarding the critical strain energy release rate was ΔG{sub c}≈ 8.4 J/m{sup 2}.

  20. Hydrofluoric–nitric–sulphuric-acid surface treatment of tungsten for carbon fibre-reinforced composite hybrids in space applications

    International Nuclear Information System (INIS)

    Highlights: • XPS and AFM analysis of the effect of hydrofluoric–nitric–sulphuric-acid on tungsten. • Dreiling's model established 54.4% thinning of WO3 due to 67 s treatment. • Strain energy release rate increased ≈8.4 J/m2 at the interface. • Failure loci analysis expressed the oxide and carbon fibre surfaces as weak points. - Abstract: Hybrid material systems, such as combinations of tungsten foils and carbon fibre-reinforced plastic (CFRP), are replacing metal alloy concepts in spacecraft enclosures. However, a good adhesion between the tungsten oxide scale and the epoxy resin used is required. Here, the effects of a hydrofluoric–nitric–sulphuric-acid (HFNS) treatment on tungsten oxides and subsequent adhesion to CFRP are analysed using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fracture testing. The work shows that HFNS treatment results in decreased oxygen content, over 50% thinner tungsten trioxide (WO3) layer and increased nano-roughness on thin tungsten foils. Fracture testing established a 39% increase in the average critical strain for tungsten–CFRP specimens after HFNS treatment was carried out on tungsten. The effect of the oxide scale modification regarding the critical strain energy release rate was ΔGc≈ 8.4 J/m2

  1. Hydrofluoric-nitric-sulphuric-acid surface treatment of tungsten for carbon fibre-reinforced composite hybrids in space applications

    Science.gov (United States)

    Kanerva, M.; Johansson, L.-S.; Campbell, J. M.; Revitzer, H.; Sarlin, E.; Brander, T.; Saarela, O.

    2015-02-01

    Hybrid material systems, such as combinations of tungsten foils and carbon fibre-reinforced plastic (CFRP), are replacing metal alloy concepts in spacecraft enclosures. However, a good adhesion between the tungsten oxide scale and the epoxy resin used is required. Here, the effects of a hydrofluoric-nitric-sulphuric-acid (HFNS) treatment on tungsten oxides and subsequent adhesion to CFRP are analysed using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fracture testing. The work shows that HFNS treatment results in decreased oxygen content, over 50% thinner tungsten trioxide (WO3) layer and increased nano-roughness on thin tungsten foils. Fracture testing established a 39% increase in the average critical strain for tungsten-CFRP specimens after HFNS treatment was carried out on tungsten. The effect of the oxide scale modification regarding the critical strain energy release rate was ΔGc≈ 8.4 J/m2.

  2. Analysis of Failure Mechanisms and Hybrid Effects in Carbon Fibre Reinforced Thermoplastic Composites (Analyse van faalmechanismen en hybride effecten in koolstofvezelversterkte thermoplastische composieten)

    OpenAIRE

    Taketa, Ichiro

    2011-01-01

    First part of this thesis studies tensile failure mechanisms of unidirectional laminates made of carbon fibre reinforced thermoplastic composites. Global mechanical properties (such as 0° and 90° tensile strength), and microscopic mechanical properties (such as work of adhesion, matrix modulus, matrix residual stress, interfacial shear strength and interlaminar fracture toughness in mode II) are experimentally evaluated. Comparison of various prepreg systems using the same carbon fi...

  3. Flexural behaviour of partially bonded carbon fibre reinforced polymers strengthened concrete beams: Application to fire protection systems design

    International Nuclear Information System (INIS)

    Highlights: • The mechanical behaviour of partially bonded CFRP strengthened beams was modelled. • Two dimensional non-linear finite element models were developed. • Partially bonded beams can present similar flexural strength to fully bonded ones. • Relations between the bonded length and the strength reduction were proposed. • The proposed relations were used for the design of fire protection systems. - Abstract: Recent fire resistance tests on reinforced concrete (RC) beams strengthened with carbon fibre reinforced polymers (CFRP) laminates showed that it is possible to attain considerable fire endurance provided that thermal insulation is applied at the anchorage zones of the strengthening system. With such protection, although the CFRP laminate prematurely debonds in the central part of the beam, it transforms into a cable fixed at the extremities until one of the anchorage zones loses its bond strength. The main objective of this paper is to propose a simplified methodology for the design of fire protection systems for CFRP strengthened-RC beams, which is based on applying thicker insulation at the anchorage zones (promoting the above mentioned “cable behaviour”) and a thinner one at the current zone (avoiding tensile rupture of the carbon fibres). As a first step towards the validation of this methodology, finite element (FE) models were developed to simulate the flexural behaviour at ambient temperature of full-scale RC beams strengthened with CFRP laminates according to the externally bonded reinforcement (EBR) and near surface mounted (NSM) techniques, in both cases fully or partially bonded (the latter simulating the cable). The FE models were calibrated with results of 4-point bending tests on small-scale beams and then extended for different beam geometries, with spans (L) varying from 2 m to 5 m, in which the influence of the CFRP bonded length (lb) and the loading type (point or uniformly distributed) on the strength reduction was

  4. Durability of fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Hansen, Kurt Kielsgaard

    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...

  5. Continuous jute fibre reinforced laminated paper composite and reinforcement-fibre free paper laminate

    Indian Academy of Sciences (India)

    B B Verma

    2009-12-01

    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 properties than single paper strip. The studies further show that an appreciable improvement in tensile properties can be achieved by introducing continuous jute fibre in paper laminates.

  6. Scanning induction thermography (SIT) for imaging damages in carbon-fibre reinforced plastics (CFRP) components

    Science.gov (United States)

    Thomas, K. Renil; Balasubramaniam, Krishnan

    2015-03-01

    Scanning Induction Thermography (SIT) combines both Eddy Current Technique (ECT) and Thermographic Non-Destructive Techniques (TNDT) [1],[2]. This NDT technique has been earlier demonstrated for metallic components for the detection of cracks, corrosion, etc.[3]-[9] Even though Carbon-Fiber Reinforced Plastics (CFRP) has a relatively less electrical conductivity compared to metals, it was observed that sufficient heat could be generated using induction heating that can be used for nondestructive evaluation using the Induction Thermography technique. Also, measurable temperatures could be achieved using relatively less currents, when compared to metals. In Scanning Induction Thermography (SIT) technique, the induction coil moves over the sample at optimal speeds and the temperature developed in the sample due to Joule heating effects is captured as a function of time and distance using an IR camera in the form of video images. A new algorithm is also presented for the analysis of the video images for improved analysis of the data obtained. Several CFRP components were evaluated for detection of impact damage and delaminations using the SIT technique.

  7. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    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......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...... pore structure are made on specimens drilled or sawed from beams after unloading (mechanical load). The pore structure of the concretes will be studied by microscopy, sorption and suction curves. The test programme involves three different concrete qualities (water-cement ratios). Both steel fibres (ZP...

  8. Infrared thermography and ultrasonics to evaluate porosity of carbon fibre reinforced composites

    OpenAIRE

    Toscano, Cinzia

    2013-01-01

    Il presente lavoro di Tesi è incentrato sulle problematiche relative al controllo non distruttivo di materiali compositi, di tipo resina epossidica rinforzata con fibre di carbonio, affette da porosità. La porosità è un difetto che tipicamente viene riscontrato a valle del processo di fabbricazione di tali materiali, ed è genralmente causata da cicli di cura non ottimizzati o altre problematiche legate allo specifico processo di manifattura. La sua rivelazione è di primaria importanza in quan...

  9. Laser treatment of carbon fibre reinforced thermoplastic matrix for adhesive bonding

    Science.gov (United States)

    Genna, S.; Leone, C.; Ucciardello, N.; Giuliani, M.

    2016-05-01

    In the present study, laser surface treatment of CFRP made of PPS thermoplastic matrix by means of a 30 W Q-Switched Yb:YAG fiber laser, is investigated with the aim to improve adhesive bonding. The process parameters pulse power, scanning speed, hatch distance and scanning strategy, were varied to the aim to study the influence of the process condition on the first top resin layer removal and fibre damage. The operating window was experimentally determined. The effectiveness of laser treatment was verified by single lap shear test.

  10. Design Methods for Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Stang, Henrik

    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....

  11. 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

  12. Frost resistance of fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    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 the......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...

  13. The carbon fibre market and uses for composite wind blades

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, J.R. [Tenax Fibers Gmbh and Co. KG, Wuppertal (Germany)

    1996-09-01

    Due to its excellent fatigue properties, low weight and high stiffness, carbon fibre reinforced plastic (CFRP) is the ideal material to use for the manufacture of wind blades. The present use of CFRP in the wind energy sector however is very low in comparison to glass fibre reinforced plastic (GFRP) materials. The main reason for this low use of CFRP is cost since at present times carbon fibre is valued ten times as much as glass fibre. This paper introduces carbon fibre as an alternative material to glass and examines the use of CFRP components in other high fatigue applications. (au)

  14. Fracture characterisation of short bamboo fibre reinforced polyester composites

    International Nuclear Information System (INIS)

    In the study, fracture behaviour of short bamboo fibre reinforced polyester composites is investigated. The matrix is reinforced with fibres ranging from 10 to 50, 30 to 50 and 30 to 60 vol.% at increments of 10 vol.% for bamboo fibres at 4, 7 and 10 mm lengths respectively. The results reveal that at 4 mm of fibre length, the increment in fibre content deteriorates the fracture toughness. As for 7 and 10 mm fibre lengths, positive effect of fibre reinforcement is observed. The optimum fibre content is found to be at 40 vol.% for 7 mm fibre and 50 vol.% for 10 mm fibre. The highest fracture toughness is achieved at 10 mm/50 vol.% fibre reinforced composite, with 340% of improvement compared to neat polyester. Fractured surfaces investigated through the Scanning Electron Microscopy (SEM) describing different failure mechanisms are also reported.

  15. Radiation curing of carbon fibre composites

    International Nuclear Information System (INIS)

    Epoxy/carbon fibre reinforced composites were produced by means of e-beam irradiation through a pulsed 10 MeV electron beam accelerator. The matrix consisted of a difunctional epoxy monomer (DGEBA) and an initiator of cationic polymerisation, while the reinforcement was a unidirectional high modulus carbon fibre fabric. Dynamic mechanical thermal analysis was carried out in order to determine the cross-linking degree. The analysis pointed out a nonuniformity in the cross-linking degree of the e-beam cured panels, with the formation of clusters at low Tg (glass transition temperature) and clusters at high Tg. An out-of-mould post irradiation thermal treatment on e-beam cured samples provides a higher uniformity in the network although some slight degradation effects. Mode I delamination fracture toughness and Interlaminar Shear Strength (ISS) were also investigated by means of Double Cantilever Beam (DCB) and Short Beam Shear tests, respectively. Results from this mechanical characterisation allowed to correlate fracture toughness of the bulk matrix resin, cross-linking density and fibre/matrix interaction to the delamination fracture behaviour of the fibre reinforced material. - Highligths: • Epoxy/carbon fibre composites were produced by means of e-beam irradiation. • DMTA analysis pointed out a nonuniformity in the cross-linking degree of the material. • An out-of-mould post irradiation thermal treatment allows a higher uniformity. • Mechanical tests were interpreted on the basis of the cross-linking density and fibre/matrix interaction

  16. Reinforcing of Cement Composites by Estabragh Fibres

    Science.gov (United States)

    Merati, A. A.

    2014-04-01

    The influence of Estabragh fibres has been studied to improve the performance characteristics of the reinforced cement composites. The concrete shrinkage was evaluated by counting the number of cracks and measuring the width of cracks on the surface of concrete specimens. Although, the Estabragh fibres lose their strength in an alkali environment of cement composites, but, the ability of Estabragh fibres to bridge on the micro cracks in the concrete matrix causes to decrease the width of the cracks on the surface of the concrete samples in comparison with the plain concrete. However, considering the mechanical properties of specimens such as bending strength and impact resistance, the specimens with 0.25 % of Estabragh fibre performed better in all respects compared to the physical and mechanical properties of reinforced cement composite of concrete. Consequently, by adding 0.25 % of Estabragh fibres to the cement composite of concrete, a remarkable improvement in physical and mechanical properties of fibre-containing cement composite is achieved.

  17. 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

  18. Applications and Properties of Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Amit Rai1 ,

    2014-05-01

    Full Text Available In conventional concrete, micro-cracks develop before structure is loaded because of drying shrinkage and other causes of volume change. When the structure is loaded, the micro cracks open up and propagate because of development of such micro-cracks, results in inelastic deformation in concrete. Fibre reinforced concrete (FRC is cementing concrete reinforced mixture with more or less randomly distributed small fibres. In the FRC, a numbers of small fibres are dispersed and distributed randomly in the concrete at the time of mixing, and thus improve concrete properties in all directions. The fibers help to transfer load to the internal micro cracks. FRC is cement based composite material that has been developed in recent years. It has been successfully used in construction with its excellent flexural-tensile strength, resistance to spitting, impact resistance and excellent permeability and frost resistance. It is an effective way to increase toughness, shock resistance and resistance to plastic shrinkage cracking of the mortar. These fibers have many benefits. Steel fibers can improve the structural strength to reduce in the heavy steel reinforcement requirement. Freeze thaw resistance of the concrete is improved. Durability of the concrete is improved to reduce in the crack widths. Polypropylene and Nylon fibers are used to improve the impact resistance. Many developments have been made in the fiber reinforced concrete.

  19. STUDIES OF DURABILITY ASPECTS OF FIBRE REINFORCED CONCRETE

    Directory of Open Access Journals (Sweden)

    D. MARUTHACHALAM

    2012-02-01

    Full Text Available This paper presents a detailed experimental study on sulphate attack, depth of carbonation, alkalinity measurement on fibre reinforced concrete at ages 28 days, 56 days, and 90 days. The main variable investigated in this study is variation of fibre dosage of 0.1%, 0.2%, and 0.3%. The concrete produced by the addition of fly ash and metakaolin as a partial replacement of cement. The compressive strength, weight loss and hardness of concrete were studied. Test results indicate that use of fibre in concrete has improved performance of concrete. A simple regression equation has been proposed to study the behaviour of concrete under sulphate attack, depth of carbonation.

  20. 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.

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

    International Nuclear Information System (INIS)

    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

  2. Adhesion, differentiation and immune activation of human osteogenic cells in cultures on carbon-fibre reinforced carbon composites

    Czech Academy of Sciences Publication Activity Database

    Bačáková, Lucie; Starý, V.; Glogar, Petr; Lisá, Věra

    2003-01-01

    Roč. 6, - (2003), s. 8-9. ISSN 1429-7248. [Konferencja Naukowa "Biomaterialy w medycynie i weterynarii" /13./. Rytro, 09.10.2003-12.10.2003] R&D Projects: GA MŠk OC 527.130 Institutional research plan: CEZ:AV0Z3046908; CEZ:AV0Z5011922 Keywords : carbon-carbon composites * surface properties * bone tissue engineering Subject RIV: JI - Composite Materials

  3. Applications of magnetically active fibre reinforced composites

    Science.gov (United States)

    Etches, Julie; Bond, Ian; Mellor, Philip

    2005-05-01

    As the application of fibre reinforced polymer composites (FRP) becomes more widespread there is a desire to add functionality beyond that of simple mechanical properties in order to facilitate the development of 'smart' materials. For example, the functionality being discussed in this paper is the imparting of significant magnetic properties to a FRP. This can take the form of soft magnetic performance for use in electrical machines or hard magnetic performance for novel forms of sensing or power generation. It has been demonstrated that by using hollow glass fibres as a reinforcement, magnetic material can be introduced into these fibres without significant effects on the structural behaviour of the FRP. The current studies have included the assessment of such a magnetic FRP in a variety of applications. The addition of hard magnetic materials, e.g. magnetite and barium ferrite, has been achieved through the use of nanopowders and the resulting FRP has been assessed for morphing structures applications. The magnitude of magnetic performance that can be currently achieved is controlled by the availability of suitable magnetic materials in fine powder form and the volume of magnetic material which can be incorporated within the fibres.

  4. Fibre Reinforced Concrete: Optimization of fibre content and shear capacity of dapped-end beams

    OpenAIRE

    Boix Roca, Miguel

    2013-01-01

    Fibre reinforced concrete is a type of concrete which improves the fracture characteristics and structural behaviour through the fibres ability to bridge cracks: it offers a much more ductile response. Thus, the principal aim of this project has been to improve the current knowledge of the fresh and mechanical behaviour of fibre reinforced concrete. When casting FRC, the addition of fibres can substitute traditional reinforcement, which reduces the worker hours required and improves economic ...

  5. Extended proof of fibre-reinforced laminates with holes

    Directory of Open Access Journals (Sweden)

    L. Kroll

    2009-03-01

    Full Text Available Purpose: A calculation method for the strength prediction of tensioned laminated plates with circular notches is presented.Design/methodology/approach: An extensive basis of experimental data from tensile fracture tests on carbon fibre reinforced specimens with circular notches was used to analyse factors determining the notched strength. The proposed extension of the known Whitney-Nuismer and Karlak Point Stress Criteria improves the strength prediction accuracy through introduction of a special coefficient function that takes into account the dependence between stress gradients in the notch near-field and the distance of the outer boundary.Findings: It was found that the theoretical, notch size and outer boundary independent stress concentration factor is not sufficient for a reliable prediction of the notched strength. The presented results show that calculation procedure based on fundamental mechanical relations of the elasticity theory with few experimentally determined factors delivers results which good agree with experiments.Research limitations/implications: The calculation procedure was verified on the representative population of tensile specimens made of several types of carbon fibre reinforced laminates used in the aerospace industry.Practical implications: As openings represent relevant sites of failure in the construction, an accurate calculation of the notched strength is essential for the lightweight-oriented design of fibre-reinforced elements. The presented procedure is relevant for construction of practically important tensioned elements with circular holes.Originality/value: The presented formulation of the phenomenological “characteristic distance” concept and its thorough experimental verification is original.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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 of...... miniaturized objects with relatively high surface quality compared to other additive manufacturing technologies. This paper aim to move fibre reinforced resin parts one step closer towards mechanically strong production-quality components....

  7. Adhesive bonding of discontinuous carbon fibre composites: an experimental investigation

    OpenAIRE

    Nicholls, Tristan Kit

    2013-01-01

    The excellent specific stiffness and strength of carbon fibre reinforced polymer composites means that the automotive sector has been investigating methods of implementing these materials into structurally demanding applications. The work detailed within this thesis supports ongoing research at the University of Nottingham into the automated manufacture of discontinuous carbon fibre reinforced polymer composite materials. Advances in the automation of composites manufacturing has meant that m...

  8. 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.

  9. Improvement of shear capacity of existing reinforced concrete members with sheet type carbon fibre reinforcement. Sheet jo renzoku tanso sen[prime]i hokyozai wo mochiita kisetsu tekkin concrete buzai no sendan tairyoku kojo koka ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Uji, K. (Taisei Corp., Tokyo (Japan))

    1992-07-15

    Studies were conducted on the preventive effect of Carbon fibre sheets(CFS) used for reinforcement of brittle shear-fracture of existing concrete members, and on their fundamental anti-shear mechanism. The following were made clear by the experiments with concrete beams. Concrete members without stirrups were reinforced in their shear capacity to a great extent by winding them up or sticking onto them with CFS. Concrete members with stirrup were able to reduce the shear stress of stirrups to bear by disposing CFS. The strain values of CFS and a stirrup differ with each other even in the same location, since the elongation of CFS stuck onto concrete took place on shearing only in the cracking spot, whereas that of a stirrup was homologous along its length. Therefore, tensile force on CFS and a stirrup did not correspond to a ratio of reinforced areas by them. Though the cross section area reinforced by stirrups was four times as large as that by CFS, tensile force on stirrups was 1.2 times as mush as that on CFS. This means that CFS shears more shearing stress than stirrups. 12 refs., 12 figs., 6 tabs.

  10. The Surface Finish of Thermally Aged Carbon Fibre Reinforced Composites Using E-glass as a Surface Barrier

    Science.gov (United States)

    de Souza, M. L.; Fox, B. L.

    2015-10-01

    This work investigated the effect of woven E-glass mass (25 g/m2, 50 g/m2, 85 g/m2, 135 g/m2) on the painted surface finish of various thermoset (EPIKOTETM RIM935, EPIKOTETM 04434, Ultratec LpTM ES300, Ultratec LpTM SPV6035) carbon fibre composite laminates, before and after aging at 95 °C for 168 h. The as-moulded laminate surfaces were evaluated using surface profilometry techniques and the painted and aged surfaces were evaluated using a wave-scan distinctness of image (DOI) instrument. It was found that the 25 g/m2 E-glass surface layer assisted with reducing the roughness of the as-moulded surfaces and the long-term waviness of the painted surfaces due to the increase in resin-richness at the surface. The EPIKOTETM 04434 resin system that contained diglycidyl ether of bisphenol F (DGEBF) epoxy had the least change in long-term waviness with thermal aging due to the rigid fluorene-based backbone in comparison to the diglycidyl ether of bisphenol A (DGEBA) systems.

  11. Concrete reinforced by braided fibre composite rods

    OpenAIRE

    Fangueiro, Raúl; Sousa, Guilherme José Miranda de; Soutinho, Hélder Filipe Cunha; Jalali, Said; Araújo, Mário Duarte de

    2005-01-01

    One of the most serious problems affecting concrete is corrosion of the steel reinforcement. Corrosion may occur due to reaction of lime present in hydrated cement with carbon dioxide or to the action of chlorides. The braiding technique is probably the most ancient production process for textile structures. Normally used for ropes and cables, braided fabrics are also very interesting for composite reinforcements due to their characteristics: in-plane multiaxial ...

  12. Fatigue damage propagation in unidirectional glass fibre reinforced composites

    DEFF Research Database (Denmark)

    Hansen, Jens Zangenberg; Alzamora Guzman, Vladimir Joel; Østergaard, R.C.;

    2012-01-01

    Damage progression in unidirectional glass fibre reinforced composites exposed to tension fatigue is investigated, and a quantitative explanation is given for the observed stiffness loss. The stiffness degradation during fatigue is directly related to fibre breaks in the load-carrying axial fibre...... bundles. The underlying mechanisms are examined using digital microscopy, and it is postulated that fatigue damage initiates due to stress concentrations between the backing (transverse) layer and the unidirectional layer, followed by a cyclic fretting and axial fibre debonding. This fretting mechanism...... needs further attention and understanding in order to improve the fatigue life-time of glass fibre reinforced composites....

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

    OpenAIRE

    Reinders, A.H.M.E.; Wit, de, S.; Boer

    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 broad range of the solar spectrum while the material properties and integral production processes create possibilities for novel product concepts with embedded PV technology. To explore such possibi...

  14. Structural Engineering Properties of Fibre Reinforced Concrete Based On Recycled Glass Fibre Polymer (GFRP)

    OpenAIRE

    Adetiloye A; Ephraim M. E

    2015-01-01

    Glass fibre reinforced plastics (GFRP) based on resin recovered from recycling plastic waste has been shown to possess mechanical properties satisfying normative requirements. This paper investigates the flexural behavior of concrete beams reinforced with GFRP produced from resin recovered from recycled plastic wastes. A total of twelve of beams of sizes 150 ×150 ×900mm and 100 × 100 × 500mm reinforced with GFRP made from recycled glass fibre reinforced polymer was tested. The fle...

  15. Electron processing of fibre-reinforced advanced composites

    International Nuclear Information System (INIS)

    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)

  16. Sizing Procedures for a Fibre Reinforced Plastic Box

    Directory of Open Access Journals (Sweden)

    K. Kamal

    1992-10-01

    Full Text Available A fibre-reinforced plastic (FRP box is an important class of structural component employed as the bending, torsion, or bending-torsion load bearing member in the modern light- weight structures. This paper presents various steps involved in the design of such a box beginning with preliminary analysis and optimization to the final sizing. The box made up of carbon fibre composite is a typical numerical example of such FRP construction. Numerical results obtained from the static stress analysis, the panel buckling analysis and the structural optimization as used for this sizing exercise, are presented. It is believed that the complete procedure of analysis using finite element method and then sizing of any FRP box in a comprehensive way, is reported for the first time.

  17. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    A S Singha; Vijay Kumar Thakur

    2008-10-01

    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 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 Hibiscus sabdariffa fibre reinforced polymer composites such as tensile, compressive and wear properties were investigated as a function of fibre loading. Initially urea–formaldehyde resin prepared was subjected to evaluation of its optimum mechanical properties. Then reinforcing of the resin with Hibiscus sabdariffa fibre was accomplished in three different forms: particle size, short fibre and long fibre by employing optimized resin. Present work reveals that mechanical properties such as tensile strength, compressive strength and wear resistance etc of the urea–formaldehyde resin increases to considerable extent when reinforced with the fibre. Thermal (TGA/DTA/DTG) and morphological studies (SEM) of the resin and biocomposites have also been carried out.

  18. Effect of discrete fibre reinforcement on soil tensile strength

    Directory of Open Access Journals (Sweden)

    Jian Li

    2014-04-01

    Full Text Available The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure. In order to increase soil tensile strength, discrete fibre reinforcement technique was proposed. An innovative tensile apparatus was developed to determine the tensile strength characteristics of fibre reinforced soil. The effects of fibre content, dry density and water content on the tensile strength were studied. The results indicate that the developed test apparatus was applicable in determining tensile strength of soils. Fibre inclusion can significantly increase soil tensile strength and soil tensile failure ductility. The tensile strength basically increases with increasing fibre content. As the fibre content increases from 0% to 0.2%, the tensile strength increases by 65.7%. The tensile strength of fibre reinforced soil increases with increasing dry density and decreases with decreasing water content. For instance, the tensile strength at a dry density of 1.7 Mg/m3 is 2.8 times higher than that at 1.4 Mg/m3. It decreases by 30% as the water content increases from 14.5% to 20.5%. Furthermore, it is observed that the tensile strength of fibre reinforced soil is dominated by fibre pull-out resistance, depending on the interfacial mechanical interaction between fibre surface and soil matrix.

  19. Effect of discrete fibre reinforcement on soil tensile strength

    Institute of Scientific and Technical Information of China (English)

    Jian Li; Chaosheng Tang; Deying Wang; Xiangjun Pei; Bin Shi

    2014-01-01

    The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure. In order to increase soil tensile strength, discrete fibre reinforcement technique was proposed. An innovative tensile apparatus was developed to deter-mine the tensile strength characteristics of fibre reinforced soil. The effects of fibre content, dry density and water content on the tensile strength were studied. The results indicate that the developed test apparatus was applicable in determining tensile strength of soils. Fibre inclusion can significantly in-crease soil tensile strength and soil tensile failure ductility. The tensile strength basically increases with increasing fibre content. As the fibre content increases from 0%to 0.2%, the tensile strength increases by 65.7%. The tensile strength of fibre reinforced soil increases with increasing dry density and decreases with decreasing water content. For instance, the tensile strength at a dry density of 1.7 Mg/m3 is 2.8 times higher than that at 1.4 Mg/m3. It decreases by 30% as the water content increases from 14.5% to 20.5%. Furthermore, it is observed that the tensile strength of fibre reinforced soil is dominated by fibre pull-out resistance, depending on the interfacial mechanical interaction between fibre surface and soil matrix.

  20. Influence of Fibre Architecture on Mechanical Properties of Jute Fibre Reinforced Composites

    OpenAIRE

    Hasan, Md Rejaul

    2013-01-01

    Jute fibre reinforced epoxy based composites were manufactured by vacuum bagging method using three different jute fibre structures; woven fabric, non-woven mat and carded sliver. The composites were made using different number of layers of reinforcing materials. Then the tensile test on composite laminates was conducted in different directions of composites according to ASTM D 3039 standards. The tensile properties were evaluated as a function of fibre architecture (woven, non-woven and sliv...

  1. Compression properties of novel thermoplastic carbon fibre and poly-ethylene terephthalate fibre composite lattice structures

    International Nuclear Information System (INIS)

    Highlights: • An efficient manufacturing route to produce a thermoplastic lattice is presented. • The influence of core geometry on the mechanical properties have been investigated. • Thermoplastic carbon fibre structures show competitive mechanical performance. • Thermoplastic single polymer structures show better performance than foams. • Single polymer lattice cores have good recyclability and energy absorption. - Abstract: A novel manufacturing route to efficiently produce fibre composite lattice structures has been developed. By using thermoplastic composite materials, flat sheets have been continuously folded, cut into a lattice shape and joined into a sandwich structure. Carbon fibre reinforced poly-ethylene terephthalate (CPET) and poly-ethylene terephthalate fibre reinforced poly-ethylene terephthalate (SrPET) materials have been used to explore two different core options; a carbon fibre option which gives high performance but low recyclability and a single polymer PET option which gives lower performance but full recyclability. Parametric numerical simulations have been used to investigate how the various manufacturing parameters affect the mechanical performance of the core. The carbon fibre composite cores have mechanical performance on-par or better than existing metallic and composite lattice cores presented in literature. Single polymer PET cores show better performance compared to high-end foam cores but have considerable lower performance than carbon fibre lattice cores

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

    DEFF Research Database (Denmark)

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

    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...... observed correlation between the fibre volume fraction and the electrical resistivity of the composite (the SFRC) for conductive fibres and moisture saturated concrete. This indicates that the steel fibres were conducting when measuring the electrical resistivity by AC at 126 Hz. For partly saturated...... concrete the model underestimated the influence of the addition of fibres. The results indicate that the addition of steel fibres reduce the electrical resistivity of concrete if the fibres are conductive. This represents a hypothetical case where all fibres are depassivated (corroding) which was created...

  3. Fabrication and characterization of S. cilliare fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    A S Singha; Vijay Kumar Thakur

    2009-02-01

    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 a novel matrix has been reported. A systematic approach for processing of polymer is presented. Effect of fibre loading on mechanical properties like flexural, tensile, compressive and wear resistances has also been determined. Reinforcing of the RF resin with Saccharum cilliare (SC) fibre was done in the form of particle size (200 micron). Present work reveals that mechanical properties of the RF resin have been found to increase up to 30% fibre loading and then decreases. Morphological and thermal studies of the resin, fibre and particle reinforced (P-Rnf) green composites have also been studied.

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

    DEFF Research Database (Denmark)

    Svec, Oldrich

    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 and...... fills the formwork with a little or no effort. Steel fibre reinforced self-compacting concrete is a logical combination of the two types of concrete. The combination nevertheless creates several challenges. It has been observed by many authors that steel fibres orient and distribute according to the...... flow of the fibre reinforced self-compacting concrete. The orientation and distribution of the fibres results in non-homogeneous and non-isotropic mechanical properties of the structural elements. The primary aim of this research project was to develop a numerical framework capable of predicting the...

  5. Carbon fibre material for tomorrow

    International Nuclear Information System (INIS)

    As science and technology continue to cross boundaries of known practices, materials and manufacturing techniques and into the frontiers of new materials, environment and applications, the opportunities for research in materials in general will inevitably increase. The unique properties of carbon fibre which combines low weight and high stiffness, makes it in ever greater demand as substitutes for traditional materials. This is due to the rising costs of raw materials and energy and the necessity to reduce carbon dioxide emission. The carbon fibres produced are particularly of high standard in terms of quality and processing characteristics especially when it is designed in structural components in the aerospace and defence industries. This results in a well structured organisation in producing the fibre starting from its raw material to the final composite products. In achieving this effort, research and communication of the progress takes a fundamental role. (author)

  6. 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...

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    Polypropylene (PP) and polypropylene modified with maleic anhydride (MA-PP) reinforced by continuous longitudinal glass fibres have been investigated. The most prominent effect of the modification with maleic anhydride in the composite is a stronger fibre/matrix interface. The effects of...

  8. Effect of discrete fibre reinforcement on soil tensile strength

    OpenAIRE

    Jian Li; Chaosheng Tang; Deying Wang; Xiangjun Pei; Bin Shi

    2014-01-01

    The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure. In order to increase soil tensile strength, discrete fibre reinforcement technique was proposed. An innovative tensile apparatus was developed to determine the tensile strength characteristics of fibre reinforced soil. The effects...

  9. Mechanical Properties of Palm Fibre Reinforced Recycled HDPE

    OpenAIRE

    Aldousiri, B.; M. Alajmi; Shalwan, A.

    2013-01-01

    Recently, recycled thermoplastic polymers become an alternative resource for manufacturing industrial products. However, they have low mechanical properties compared to the thermosets. In this paper, an attempt has been made to enhance the mechanical properties of recycled high density polyethylene (HDPE) with chopped strand mat (CSM) glass fibres as a synthetic reinforcement and with short oil palm fibres as a biodegradable (natural) reinforcement. The effects of volume fraction of both synt...

  10. Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres

    Directory of Open Access Journals (Sweden)

    Luiz Claudio Pardini

    2002-10-01

    Full Text Available Carbon fibres and glass fibres are reinforcements for advanced composites and the fiber strength is the most influential factor on the strength of the composites. They are essentially brittle and fail with very little reduction in cross section. Composites made with these fibres are characterized by a high strength/density ratio and their properties are intrisically related to their microstructure, i.e., amount and orientation of the fibres, surface treatment, among other factors. Processing parameters have an important role in the fibre mechanical behaviour (strength and modulus. Cracks, voids and impurities in the case of glass fibres and fibrillar misalignments in the case of carbon fibres are created during processing. Such inhomogeneities give rise to an appreciable scatter in properties. The most used statistical tool that deals with this characteristic variability in properties is the Weibull distribution. The present work investigates the influence of the testing gage length on the strength, Young's modulus and Weibull modulus of carbon fibres and glass fibres. The Young's modulus is calculated by two methods: (i ASTM D 3379M, and (ii interaction between testing equipment/specimen The first method resulted in a Young modulus of 183 GPa for carbon fibre, and 76 GPa for glass fibre. The second method gave a Young modulus of 250 GPa for carbon fibre and 50 GPa for glass fibre. These differences revelead differences on how the interaction specimen/testing machine can interfere in the Young modulus calculations. Weibull modulus can be a tool to evaluate the fibre's homogeneity in terms of properties and it is a good quality control parameter during processing. In the range of specimen gage length tested the Weibull modulus for carbon fibre is ~ 3.30 and for glass fibres is ~ 5.65, which indicates that for the batch of fibres tested, the glass fibre is more uniform in properties.

  11. Multilayered Glass Fibre-reinforced Composites In Rotational Moulding

    Science.gov (United States)

    Chang, W. C.; Harkin-Jones, E.; Kearns, M.; McCourt, M.

    2011-05-01

    The potential of multiple layer fibre-reinforced mouldings is of growing interest to the rotational moulding industry because of their cost/performance ratio. The particular problem that arises when using reinforcements in this process relate to the fact that the process is low shear and good mixing of resin and reinforcement is not optimum under those conditions. There is also a problem of the larger/heavier reinforcing agents segregating out of the powder to lay up on the inner part surface. In this study, short glass fibres were incorporated and distributed into a polymer matrix to produce fibre-reinforced polymer composites using the rotational moulding process and characterised in terms of morphology and mechanical properties.

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

    Science.gov (United States)

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

    2015-05-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hopmann, Ch.; Weber, M.; Haag, J. van; Schöngart, M. [Institute of Plastics Processing (IKV) at RWTH Aachen University, Pontstr. 49, 52062 Aachen (Germany)

    2015-05-22

    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.

  14. Effect of Steel Fibre Content on Bending and Compression Behaviour of Fibre Reinforced Concrete

    OpenAIRE

    Šahmenko, G; Krasņikovs, A; Lapsa, V; Teļnova, I; Mačanovskis, A

    2010-01-01

    Steel fibre reinforced concrete (SFRC) as modern perspective building material is increasingly used in diverse civil engineering applications. In SFRG mox fibres traditionally are the most expensive component, so its rational use is an actual task of SFRC mix design. In present investiganion different types of commercially available fibers, having different geometry, were used for SFRC samples preparation.

  15. Analytical Evaluation of Fibre-Reinforced Plastic Corrugated Sheet

    Directory of Open Access Journals (Sweden)

    C. K. Gautam

    1998-01-01

    Full Text Available Fibre-reinforced' composites playa lead role as advanced materials in modem day structures.This paper reports fabrication and testing offibre-reinforced corrugated sheet employing 4-point bend loading. An in-depth analysis has been carried out using ANSYS, a finite element method package.The theoretical results obtained are compared with the experimental values. The values ofboth inputsshowed similar results. conforming at a particular boundary condition. However, more similarexperiments "on such fibre-reinforced plastic corrugated sheets have been suggested for -better comparison.

  16. Carbon nanofibre reinforcement of soft materials

    International Nuclear Information System (INIS)

    In elastomeric matrices carbon nanofibres are found to be twenty times more effective than carbon black as a reinforcing filler. In hard matrices, by contrast, reinforcement is minimal. Tensile and dynamic mechanical tests were performed to elucidate the mechanism of reinforcement in order to explain the superior performance in soft matrices. Small-angle neutron scattering and ultra-small-angle X-ray scattering were used to quantify filler morphology, which turns out to be the key factor that limits reinforcement potential. The presence of fractal cluster formed by agglomeration of the nanofibres reduces the effective aspect ratio of the nanotubes. Clustering, however, introduces a new reinforcement mechanism based on elastic deformation of the fibre clusters. This mechanism is operative in soft matrices but not in hard matrices, thus explaining the enhanced performance in soft matrices.

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

    International Nuclear Information System (INIS)

    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.

  18. 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.

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

    Science.gov (United States)

    Kechaou, B.; Salvia, M.; Fakhfakh, Z.; Juvé, D.; Boufi, S.; Kallel, A.; Tréheux, D.

    2008-11-01

    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. Tréheux, Composites Science and Technology 64 (2004) 1467], or tribological [B. Kchaou, C. Turki, M. Salvia, Z. Fakhfakh, D. Tréheux, 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.

  20. Mechanical investigation of fibre reinforced materials for superconducting poloidal field coil design

    International Nuclear Information System (INIS)

    This Paper reports the results of flexural and shear measurements of fibre reinforced plastic materials. The materials tested were carbon fibre reinforced plastics (CFRP) and glass fibre reinforced plastics (GFRP). The objectives of the tests were to determine the mechanical properties of the industrially manufactured thick walled structures. The rectangular hollow section made of CFRP material produced has a wall thickness of ∼ 30 mm. The anisotropic characteristics of the flexural properties were determined at ambient temperature and at 77 K. In addition, pultruded GFRP complex shaped sections were measured with respect to their mechanical behaviour. Results on the thermal shrinkage measurements of CFRP- and GFRP-structures are also reported. An evaluation of the data and their impact on design were discussed under the consideration of superconducting poloidal field coil aspects. (author)

  1. INFLUENCE OF FIBRE VOLUME REINFORCEMENT IN DRILLING GFRP LAMINATES

    Directory of Open Access Journals (Sweden)

    D. ABDUL BUDAN

    2011-12-01

    Full Text Available This paper presents an investigation on the influence of fiber volume reinforcement on various aspects of machining. Drilling experiments were conducted to study the tool wear, surface finish, delamination factor and hole quality on GFRP composites. The work reports the variation of tool wear, surface roughness, hole quality, chip characteristics, delamination factor with the variation of fibre volume reinforcement. Results revealed that the increase in fiber percentage increased the tool wear, delamination factor, surface roughness value and decreased hole quality. Minimum surface roughness, tool wear and better hole quality was obtained for 30% fibre content composites. 70% Fibre content composites produced hazardous surface roughness. Pull out of fibres and fibril formation are significant in decreasing the hole quality and increased surface roughness. Increased tool – fibre interaction and thermal softening of the tool causes increased tool wear. In higher fibre content composites, extensive plasticity was absent consequently brittle ceramic fibres were fractured easily. Hence small segment type chips were obtained. The fibre pull out and fibrils present near the hole exit forms the remainder of the laminate causes increased damage zone near the hole exit. Hence high delamination factor was obtained.

  2. 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'. PMID:27242306

  3. Dynamic fracture behaviour in fibre-reinforced cementitious composites

    Science.gov (United States)

    Yu, Rena C.; Cifuentes, Héctor; Rivero, Ignacio; Ruiz, Gonzalo; Zhang, Xiaoxin

    2016-08-01

    The object of this work is to simulate the dynamic fracture propagation in fibre-reinforced cementitious composites, in particular, in steel fibre reinforced concrete (SFRC). Beams loaded in a three-point bend configuration through a drop-weight impact device are considered. A single cohesive crack is assumed to propagate at the middle section; the opening of this crack is governed by a rate-dependent cohesive law; the fibres around the fracture plane are explicitly represented through truss elements. The fibre pull-out behaviour is depicted by an equivalent constitutive law, which is obtained from an analytical load-slip curve. The obtained load-displacement curves and crack propagation velocities are compared with their experimental counterparts. The good agreement with experimental data testifies to the feasibility of the proposed methodology and paves the way to its application in a multi-scale framework.

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

    International Nuclear Information System (INIS)

    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.

  5. Reliability approach for fibre-reinforced composites design

    OpenAIRE

    Dehmous, Hocine; Welemane, Hélène; Karama, Moussa; Aît Tahar, Kamel

    2008-01-01

    This study aims at investigating the mechanical reliability of unidirectional fibre-reinforced composites in view of their design optimization. Owing to the manufacturing process, many uncertainties affect inherently the properties of these materials. Besides, the brittle character of the fibre failure leads to important safety factors that limit their development for engineering applications. The objective is to get a realistic evaluation of the mechanical reliability of such structures whic...

  6. Mechanical Properties of SiC long fibre reinforced Copper

    International Nuclear Information System (INIS)

    Full text of publication follows: SiC fibre reinforced copper is a candidate material for the divertor heat sink of future fusion reactors. The composite combines the high thermal conductivity of the matrix material with the high strength of the fibre reinforcement. Future fusion reactors like DEMO will operate with cooling temperatures of at least 300 deg. C in the divertor heat sink for efficient energy production. This will lead to temperatures of up to 550 deg. C at the interface between plasma facing material (W,C) and heat sink material (CuCrZr). To strengthen this zone a metal matrix composite is suggested consisting of SiC long fibre reinforced copper. SiC fibres (SCS 6, Specialty Materials) were coated with a 100-nm-thick titanium interlayer by magnetron sputtering for improved bonding. Subsequently an 80-μm-thick copper layer as matrix material was galvanically deposited. The thickness of the copper coating defines the fibre volume fraction in the composite. The coated single fibres were etched to remove an oxygen layer and packed into a copper capsule for hot isostatic pressing at 650 deg. C and 100 MPa to form the composite. The tensile strength of the composite in dependence on the fibre volume fraction was determined with tensile tests at room temperature as well as at 550 deg. C. For a composite with a fibre volume fraction of 10% a tensile strength of 260 MPa and a Young's modulus of 145 GPa at room temperature was determined. A composite with 17 % fibre volume fraction has a tensile strength of 100 MPa and a Young's modulus of 112 GPa at 550 deg. C. (authors)

  7. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Nielsen, Laila

    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...... (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...... fibres and the influence of fibres and cracks on the water uptake is discussed....

  8. 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...... with perfectly aligned fibres, and kink band formation at a peak stress in a composite with a band of imperfect material....

  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

    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. Mechanical Properties of Palm Fibre Reinforced Recycled HDPE

    Directory of Open Access Journals (Sweden)

    B. Aldousiri

    2013-01-01

    Full Text Available Recently, recycled thermoplastic polymers become an alternative resource for manufacturing industrial products. However, they have low mechanical properties compared to the thermosets. In this paper, an attempt has been made to enhance the mechanical properties of recycled high density polyethylene (HDPE with chopped strand mat (CSM glass fibres as a synthetic reinforcement and with short oil palm fibres as a biodegradable (natural reinforcement. The effects of volume fraction of both synthetic and natural fibres on tensile, compression, hardness, and flexural properties of the HDPE were investigated. The failure mechanism of the composite was studied with the aid of optical microscopy. Tensile properties of the HDPE composites are greatly affected by the weight fraction of both the synthetic and the natural fibres. The higher strength of the composites was exhibited when at higher weight fraction of both natural and syntactic fibres which was about 50 MPa. Date palm fibre showed good interfacial adhesion to the HDPE despite the untreated condition used. On the other hand, treatment of the fibres is recommended for higher tensile performance of the composites.

  11. Interfacial fracture of the fibre-metal laminates based on fibre reinforced thermoplastics

    International Nuclear Information System (INIS)

    As the adhesion quality plays an important role in determining the mechanical performance and environmental stability of most types of fibre-metal laminates (FMLs), investigating the interfacial fracture properties becomes one of the key factors for the improvement. Adhesion of a self-reinforced polypropylene (SRPP) and glass fibre reinforced polypropylene (GFPP) based FML is evaluated experimentally. Single Cantilever Beam (SCB) tests were performed to access interfacial fracture energy (Gc) of the bi-material laminates and their associated interlayer materials. Simulations mimicking the experiments were also performed. The energy needed to fracture was obtained experimentally and also via stress intensity factor from the simulations. The test results show that good adhesion between the aluminium and fibre reinforced thermoplastics can be achieved using a sulphuric acid anodising surface pre-treatment. Further examination has shown that the edges of the test samples highlighted the presence of significant fibre bridging in the SRPP and plastics deformation in the GFPP. - Highlights: • Adhesion of a self-reinforced polypropylene and glass fibre reinforced polypropylene is evaluated. • Single Cantilever Beam tests were performed to access interfacial fracture energy. • The energy needed to fracture was obtained experimentally and also via stress intensity factor from the simulations. • The test results show that best adhesion is achieved using a sulphuric acid anodizing surface pre-treatment

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

    OpenAIRE

    Lee, C.H.; Mohd. Sapuan Salit; M. R. Hassan

    2014-01-01

    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 flammabilit...

  13. The investigation on the workability of fibre cocktail reinforced self-compacting high performance concrete

    OpenAIRE

    Ding Yining; Liu Siguo; Zhang Yulin; Thomas, A.

    2008-01-01

    The workability, the strength and the toughness are the significant factors for self-compacting-high performance concrete (SCHPC). The workability is a significant precondition for application of the Fibre Reinforced SCHPC. This paper presents research results on the workability of Monofibre and Fibre Cocktail (hybrid steel-polypropylene fibre) Reinforced SCHPC. Lots of mixtures made with steel fibres, PP-fibres and fibre cocktail of various dosages have been investigated. The mixtur...

  14. Blast impact behaviour of concrete with different fibre reinforcement

    OpenAIRE

    Drdlová Martina; Čechmánek René; Řídký Radek

    2015-01-01

    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 concre...

  15. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Nielsen, Laila

    (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...

  16. STRAIN HARDENING PROPERTIES OF STEEL FIBRE REINFORCED LATEX CONCRETE COMPOSITE

    Directory of Open Access Journals (Sweden)

    V.M. Sounthararajan

    2013-04-01

    Full Text Available Steel fibre addition in concrete possesses high merits in terms of achieving homogeneity and tensile strength properties. Polymeric addition in concrete has high advantages in terms of pore fillingeffect and subsequent increase in durability index. The combined addition of steel and polymeric latex additions in concrete leads to increased strength, durability, toughness, resistance to cracking and crack propagation. Studies were conducted in the present study to analyse the properties of concrete that can be further improved with the addition of polymer styrene butadiene rubber emulsion (SBR along with steel fibres. In this research analysis, styrene-butadiene rubber (SBR latex as a polymeric admixture was used in steel fibre reinforced concrete. The effect of curing conditions on the strength gain properties of composite steel fibre latex matrix on the compressive, flexural strength, and split tensile test of polymermodified steel fibre reinforced concrete (PSFC concrete was examined. Including SBR latex at a certain % of binder in the PSFC concrete improves the bonds within the cement matrix and steel fibres (SF. This is due to the SBR films formed in the matrix. By the comparison of properties of SFC and PSFC, it can be shown that a tremendous increase in compressive strength when 4% and 8% SBR is added along with 0.75% and 1.5% SF. The increase in flexural strength was noticed and post cracking ductility is imparted to concrete.

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

    OpenAIRE

    Amin Noushini; Kirk Vessalas; Garo Arabian; Bijan Samali

    2014-01-01

    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),...

  18. Behavior of Mortars Reinforced by Fibres

    Czech Academy of Sciences Publication Activity Database

    Válek, M.; Procházka, P.; Drdácký, Miloš

    Žďár nad Sázavou : ŽĎAS, 2000 - (Náprstek, J.; Minster, J.), s. 181-186 ISBN 80-86246-04-3. [Engineering Mechanics 2000. Svratka (CZ), 15.05.2000-18.05.2000] Institutional research plan: CEZ:AV0Z2071913 Keywords : ancient buildings * fibres * goat hair Subject RIV: JM - Building Engineering

  19. 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 respons...

  20. Service life prediction and fibre reinforced cementitious composites

    DEFF Research Database (Denmark)

    Stoklund Larsen, E.

    , the factors affecting the pure cementitious composite are described. Different sizes and types of fibre reinforced crmentitious composites have been chosen to illustrate different ageing and deterioration mechanisms. Some ageing mechanisms can be accelerated and others cannot which is demonstrated in...

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

    DEFF Research Database (Denmark)

    Bendixen, Søren; Stang, Henrik

    1996-01-01

    -crack 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...

  2. 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 tensi

  3. 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 th...

  4. Pultrusion of fibre reinforced thermoplastic pre-impregnated materials

    OpenAIRE

    Novo, P. J.; J.S. Silva; Nunes, J. P.; MARQUES, A. T.

    2015-01-01

    Fibre reinforced thermoplastic pre impregnated materials produced continuously by diverse methods and processing conditions were used to produce composites using pultrusion. The processing windows used to produce these materials and composites profiles were optimized by using the Taguchi / DOE (Design of Experiments) methods. Composites were manufactured by pultrusion and compression moulding and subsequently submitted to mechanical testing and microscopy analysis. The obtained results were ...

  5. Understanding and Improving the Elastic Compressive Modulus of Fibre Reinforced Soy-Based Polyurethane Foams

    Science.gov (United States)

    Hussain, Sadakat

    Soy-based polyurethane foams (PUFs) were reinforced with fibres of different aspect ratios to improve the compressive modulus. Each of the three fibre types reinforced PUF differently. Shorter micro-crystalline cellulose fibres were found embedded inside the cell struts of PUF and reinforced them. The reinforcement was attributed to be stress transfer from the matrix to the fibre by comparing the experimental results to those predicted by micro-mechanical models for short fibre reinforced composites. The reinforced cell struts increased the overall compressive modulus of the foam. Longer glass fibres (470 microns, length) provided the best reinforcement. These fibres were found to be larger than the cell diameters. The micro-mechanical models could not predict the reinforcement provided by the longer glass fibres. The models predicted negligible reinforcement because the very low modulus PUF should not transfer load to the higher modulus fibres. However, using a finite element model, it was determined that the fibres were providing reinforcement through direct fibre interaction with each other. Intermediate length glass fibres (260 microns, length) were found to poorly reinforce the PUF and should be avoided. These fibres were too short to interact with each other and were on average too large to embed and reinforce cell struts. In order to produce natural fibre reinforced PUFs in the future, a novel device was invented. The purpose of the device is to deliver natural fibres at a constant mass flow rate. The device was found to consistently meter individual loose natural fibre tufts at a mass flow rate of 2 grams per second. However, the device is not robust and requires further development to deliver a fine stream of natural fibre that can mix and interact with the curing polymeric components of PUF. A design plan was proposed to address the remaining issues with the device.

  6. Performance of Straight Steel Fibres Reinforced Alkali Activated Concrete

    Science.gov (United States)

    Faris, Meor Ahmad; Bakri Abdullah, Mohd Mustafa Al; Nizar Ismail, Khairul; Muniandy, Ratnasamy; Putra Jaya, Ramadhansyah

    2016-06-01

    This paper focus on the performance of alkali activated concrete produced by using fly ash activated by sodium silicate and sodium hydroxide solutions. These alkali activated concrete were reinforced with straight steel fibres with different weight percentage starting from 0 % up to 5 %. Chemical composition of raw material in the production alkali activated concrete which is fly ash was first identified by using X-ray fluorescence. Results reveal there have an effect of straight steel fibres inclusion to the alkali activated concrete. Highest compressive strength of alkali activated concrete which is 67.72 MPa was obtained when 3 % of straight fibres were added. As well as flexural strength, highest flexural strength which is 6.78 MPa was obtained at 3 % of straight steel fibres inclusions.

  7. Reinforcement of porous alginate scaffolds by incorporating electrospun fibres.

    Science.gov (United States)

    Sakai, Shinji; Takagi, Yousuke; Yamada, Yusuke; Yamaguchi, Tetsu; Kawakami, Koei

    2008-09-01

    The mechanical properties of scaffolds play a vital role in transmitting input mechanical signals to the cells within them. We aimed to modify mechanical properties of porous scaffolds by incorporating electrospun fibres into their frameworks. Porous constructs containing electrospun silicate fibres were prepared from Na-alginate aqueous solutions suspending the silicate fibres with (ASF) or without amino groups (NASF) via an all-aqueous method based on a freeze-drying technique. The repulsion forces of constructs containing ASF towards compression increased as the fibre content increased. In contrast, constructs containing NASF showed no such increases in repulsion forces. Cells seeded onto constructs containing ASF exhibited suppressed growth, similar to cells seeded onto alginate scaffolds without fibres. In contrast, cells seeded onto scaffolds containing NASF showed about two-fold faster growth than cells seeded onto scaffolds containing ASF. The differences in the mechanical properties and cell growth profiles between the scaffolds containing ASF and NASF can be explained by the formation and non-formation of electrostatic bonds between the fibres and alginate, respectively. The results obtained in the present study demonstrate the feasibility of incorporating electrospun fibres for reinforcement of alginate scaffolds and enhancement of cell growth. PMID:18689918

  8. Reinforcement of porous alginate scaffolds by incorporating electrospun fibres

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Shinji; Takagi, Yousuke; Yamada, Yusuke; Yamaguchi, Tetsu; Kawakami, Koei [Department of Chemical Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

    2008-09-01

    The mechanical properties of scaffolds play a vital role in transmitting input mechanical signals to the cells within them. We aimed to modify mechanical properties of porous scaffolds by incorporating electrospun fibres into their frameworks. Porous constructs containing electrospun silicate fibres were prepared from Na-alginate aqueous solutions suspending the silicate fibres with (ASF) or without amino groups (NASF) via an all-aqueous method based on a freeze-drying technique. The repulsion forces of constructs containing ASF towards compression increased as the fibre content increased. In contrast, constructs containing NASF showed no such increases in repulsion forces. Cells seeded onto constructs containing ASF exhibited suppressed growth, similar to cells seeded onto alginate scaffolds without fibres. In contrast, cells seeded onto scaffolds containing NASF showed about two-fold faster growth than cells seeded onto scaffolds containing ASF. The differences in the mechanical properties and cell growth profiles between the scaffolds containing ASF and NASF can be explained by the formation and non-formation of electrostatic bonds between the fibres and alginate, respectively. The results obtained in the present study demonstrate the feasibility of incorporating electrospun fibres for reinforcement of alginate scaffolds and enhancement of cell growth.

  9. Potential applications of steel fibre reinforced concrete to improve seismic response of frame structures

    International Nuclear Information System (INIS)

    Fibre reinforced concrete has gained acceptance in several civil engineering applications. The proclivity of new generation of engineers to use steel fibre reinforced concrete can be attributed to some distinct functional and structural benefits that it can provide compared to conventional reinforced concrete. Fibre reinforced concrete has been found to increase the post-cracking tensile strength of concrete thus facilitating pseudo-plastic response, improved energy absorption, and better energy dissipation capabilities that lead to better structural response under cyclic loading. These factors suggest benefits in considering the use of steel fibre reinforced concrete to enhance the structural response of reinforced concrete structures under earthquake loading. This paper summarizes useful background on steel fibre reinforced concrete, the benefits over conventional reinforced concrete, and its response to cyclic excitation. The authors believe that steel fibre reinforced concrete is a suitable ductile high performance material that is gaining acceptance for applications in frame structures and is particularly suitable for enhancing seismic response. (author)

  10. Processing of continuous fibre reinforced thermoplastics

    OpenAIRE

    Nunes, J. P.; Silva, J F; MARQUES, A. T.

    2012-01-01

    Towpregs based on different fibres and thermoplastic matrices were processed for highly demanding and more commercial applications by different composite processing technologies. In the technologies used, compression moulding and pultrusion, the final composite processing parameters were studied in order to obtain composites with adequate properties at industrial compatible production rates. The produced towpregs were tested to verify its polymer content and degree of impregnation. The obtain...

  11. Processing of continuous fibre reinforced thermoplastics

    OpenAIRE

    Nunes, J. P.; Silva, J F; MARQUES, A. T.

    2012-01-01

    Towpregs based on different fibres and thermoplastic matrices were processed for highly demanding and more commercial applications by different composite processing technologies. In the technologies used, compression moulding and pultrusion, the final composite pr ocessing parameters were studied in order to obtain composites with adequate properties at industrial compatible production rates. The produced towpregs were tested to verify its polymer content and degree of im...

  12. Structural Engineering Properties of Fibre Reinforced Concrete Based On Recycled Glass Fibre Polymer (GFRP

    Directory of Open Access Journals (Sweden)

    Adetiloye A

    2015-04-01

    Full Text Available Glass fibre reinforced plastics (GFRP based on resin recovered from recycling plastic waste has been shown to possess mechanical properties satisfying normative requirements. This paper investigates the flexural behavior of concrete beams reinforced with GFRP produced from resin recovered from recycled plastic wastes. A total of twelve of beams of sizes 150 ×150 ×900mm and 100 × 100 × 500mm reinforced with GFRP made from recycled glass fibre reinforced polymer was tested. The flexural test results yielded lower ultimate load, lower stiffness and larger deflections at the same load when compared with the control steel reinforced beam. However, the ultimate flexural strength of beams, reinforced with GFRP from recycled resin was at least four times higher than that of the control unreinforced beam. This is in agreement, quantitatively and qualitatively, with the trend of these parameters in GFRP reinforced concrete based on virgin resins. The results therefore confirm the applicability for structural uses of GFRP reinforcement made from recycled plastic waste, with the accompanying benefits of wealth creation, value addition and environmental sustainability.

  13. 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.

  14. Waste Plastic Fibre Reinforced Self Compacting Concrete

    Directory of Open Access Journals (Sweden)

    Mrs. Vijaya G.S Assistant Professor

    2016-05-01

    Full Text Available Self-compacting concrete is high performance concrete which is highly flowable, non-segregating, spread on its own weight and doesn‟t need any compaction. This paper deals with flow and strength characteristics such as compressive strength, split tensile strength, flexural strength and impact strength of Self-compacting concrete with various percentages of waste plastic fibres like 0%, 0.25%, 0.5%, 0.75%, 1.0%, 1.1%, 1.20%, 1.3% and 1.4% is added by weight of cement. The mix proportion for M40 grade of concrete was done by using Nan Su method (Cement: GGBS: Fine aggregate: Course aggregate 1: 0.705: 3.34: 2.62. Water powder (W/P ratio 0.36, cement content 280kg/m3 , GGBS 220 kg/m3 was calculated and maintained as constant throughout the experimental work for all eight mixes, only the superplastizers dosage was varied for different percentage of fibres. In this experimental investigation one control mix and eight (8 different mixes were considered. Totally 81 Cube, beam, Cylindrical specimens and square plates were casted, cured and tested as per IS specifications. For determining impact strength drop weight method was used. The results obtained indicate that fresh (workability characteristics satisfy the lower and upper limit as suggested by EFNARC. The tests on hardened properties indicate that the compressive strength, split tensile strength, flexural strength was improved proportionally with the addition of waste plastic fibers upto 1.0% by weight of cement and then decreases. The impact strength improved proportionally with addition of fibres upto 1.2% by weight of cement and then decreases.

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    Polypropylene (PP) and polypropylene modified with maleic anhydride (MA-PP) reinforced by continuous longitudinal glass fibres have been investigated. The most prominent effect of the modification with maleic anhydride in the composite is a stronger fibre/matrix interface. The effects of...... about one decade for the composite with the stronger interface by use of the maleic-anhydride grafted polypropylene matrix. During the fatigue testing, the microscopic mechanisms were monitored intermittently by a surface replication technique. From microscopic observations, it could be concluded that...

  16. Testing of Fibre Reinforced Concrete Structures : Shear Capacity of Beams with Corbel-End

    OpenAIRE

    Nordbrøden, Hanna Haugen; Weydahl, Siri Hansen

    2012-01-01

    Fibre reinforcement as a substitute for conventional bar reinforcement provides for a more efficient construction and building industry, and is therefore of high interest. Today, several countries are developing rules and regulations for the use of fibre reinforced concrete in load carrying structures.The aim of this thesis was to consider the use of fibre reinforcement in load carrying concrete structures, and the main focus was on shear capacity of corbel-end beams. The thesis was divided i...

  17. Effects of hybrid composition of LCP and glass fibres on abrasive wear of reinforced LLDPE

    Indian Academy of Sciences (India)

    S A R Hashmi; Ajay Naik; Navin Chand

    2006-02-01

    The hybrid of liquid crystalline polymer (LCP) fibres and glass fibres (GF) provide a combination of modulus and toughness to semi-crystalline linear-low-density-polyethylene (LLDPE). LCP and GF fibres reinforced composites were studied using two-body abrasion tester under different applied loads. Two sets of fibre reinforced LLDPE, 10 and 20 vol%, were investigated. The contents of LCP and glass fibres were varied as 25, 50, 75 and 100 vol% of overall volume of fibres in LLDPE. The effect of replacing glass fibre with LCP fibre on wear is reported. Wear loss increased with the applied loads and glass fibre contents in LLDPE. The replacements of glass fibres with LCP fibres improved abrasive wear resistance of composite. The composite containing 20 vol% of glass fibres in LLDPE showed the specific wear rate nearly double to that of LCP fibre reinforced LLDPE. Incorporation of LCP fibre improved wear resistance of glass fibre reinforced LLDPE. Worn surfaces were studied using SEM. Glass fibres were broken in small debris and removed easily whereas LCP fibres yielded to fibrillation during abrasive action. The overall wear rate was governed by the composition and test conditions.

  18. Optimizing the production and processing of fibre reinforced thermoplastic pre-impregnated materials

    OpenAIRE

    Novo, P. J.; Silva, J F; Nunes, J. P.; MARQUES, A. T.

    2014-01-01

    The aim of this work is to optimize the production of new continuous carbon fibres reinforced polypropylene matrix pre-impregnated materials (towpregs) continuously processed by dry deposition of polypropylene (PP) powder. The processing of the produced towpregs by pultrusion using a prototype equipment was also optimized. The method of Taguchi/DOE (Design of Experiments) was used to achieve this goal allowing improved choices of processing windows. Towpregs were characterized by scanning ele...

  19. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    and the pore structure.Mechanical load is obtained by exposing beams to 4-point bending until a predefined crack width is reached. A test arrangement is developed. The surface crack pattern is characterized using video-scanning and digital image analysis. As environmental load, exposure to 1) a...... concentrated chloride solution or 2) water (capillary suction) is used. Penetration of chlorides will be characterized qualitatively (Color-test) as well as quantitatively (Rapid Chloride Test from Germann).Additional durability tests (freeze-thaw, water vapour diffusion, chloride permeability) and studies of...... pore structure are made on specimens drilled or sawed from beams after unloading (mechanical load). The pore structure of the concretes will be studied by microscopy, sorption and suction curves. The test programme involves three different concrete qualities (water-cement ratios). Both steel fibres (ZP...

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

    OpenAIRE

    A. Abrishambaf; V.M.C.F. Cunha; Barros, J. A. O

    2015-01-01

    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 i...

  1. Influence of Alkali Treatment and Fibre Content on the Properties of Oil Palm Press Fibre Reinforced Epoxy Biocomposites

    OpenAIRE

    Obasi H.C; Iheaturu N.C; Onuoha F.N; Chike-Onyegbula C.O; Akanbi M.N; Ezeh V.O

    2016-01-01

    In the present work, oil palm press fibre reinforced epoxy composites were developed. The effect of fibre loading varying from 5 wt. % to 30 wt. % on the mechanical properties of oil palm press fibre/epoxy composite was studied. The effect of alkali treatment on mechanical properties of the composites was also investigated. The mechanical properties of treated OPPF/epoxy composites were found to be higher that the untreated oil palm press fibres. Optimum tensile, flexural and impact streng...

  2. 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

  3. Fracture Resistance Evaluation of Fibre Reinforced Brittle Matrix Composites

    Czech Academy of Sciences Publication Activity Database

    Dlouhý, Ivo; Chlup, Zdeněk

    2004, s. -. [Fractography of Advanced Ceramic s. Stará Lesná (SK), 03.10.2004-06.10.2004] R&D Projects: GA AV ČR IAA2041003; GA ČR GA101/02/0683 Institutional research plan: CEZ:AV0Z2041904 Keywords : fibre-reinforced ceramic s * glass matrix composites * chevron notch Subject RIV: JL - Materials Fatigue, Friction Mechanics

  4. Characterisation and Performance of Fibre-Reinforced Composite Restorations

    OpenAIRE

    Al-Haddad, Ala'A

    2015-01-01

    In the modern era of metal-free minimally-invasive dentistry, there is a growing tendency toward using metal-free restorative alternatives that provide not only excellent aesthetics but also enable superior durability. Fibre-reinforced composite (FRC) is one cost-effective alternative that fulfils the requirements of aesthetics and durability, and offers favourable physico-mechanical properties. Many FRC applications are well-documented in the literature, such as crowns and fixed partial dent...

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

    OpenAIRE

    ÇETİNKAYA, Nihat; Kaplan, Hasan; Ş. Murat ŞENEL

    2004-01-01

    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-F...

  6. Gas and Vapour Transport and Mechanical Properties of Carbon Nanotube and Carbon Fibre-Reinforcement of Ethylene-Octene Copolymer Membranes

    OpenAIRE

    Sedláková, Zuzana

    2014-01-01

    Helium, hydrogen, nitrogen, oxygen, methane and carbon dioxide were used for gas permeation rate measurements. Theoretical Maxwell’s model was used to predict and interpret gas transport properties in MMMs. Vapour transport properties were studied for aliphatic hydrocarbon (hexane), aromatic compound (toluene), alcohol (ethanol), as well as water. Organic vapours result more permeable than permanent gases in EOC-based membranes, with toluene and hexane permeabilities being about two orders o...

  7. AN APPLICATION OF ASYMMETRICAL GLASS FIBRE-REINFORCED PLASTICS FOR THE MANUFACTURE OF CURVED FIBRE REINFORCED CONCRETE

    Directory of Open Access Journals (Sweden)

    Henrik L. Funke

    2015-01-01

    Full Text Available There was developed a novel technological and constructive approach for the low-cost production of curved freeform formworks, which allow the production of single and double-curved fibre reinforced concrete. The scheduled approach was based on a flexible, asymmetrical multi-layered formwork system, which consists of glass-fibre reinforced plastic (GFRP. By using of the unusual anisotropic structural behavior, these GFRP formwork elements permitted a specific adjustment of defined curvature. The system design of the developed GFRP formwork was examined exhaustively. There were designed, numerically computed and produced prototypical curved freeform surfaces with different curvature radii. The fibre reinforced concrete had a compressive strength of 101.4 MPa and a 3-point bending tensile strength of 17.41 MPa. Beyond that, it was ensured that the TRC had a high durability, which has been shown by the capillary suction of de-icing solution and freeze thaw test with a total amount of scaled material of 874 g/m² and a relative dynamic EModulus of 100% after 28 freeze-thaw cycles.

  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

    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.......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...

  9. Reinforcing Efficiency of Crimped Profile of Polypropylene Fibres on the Cementitious Matrix

    OpenAIRE

    S. Thirumurugan; V.M. Sounthararajan; Mr. A. Sivakumar

    2013-01-01

    Fibre reinforcement in concrete is an effective solution for improving tensile properties of concrete. Different types of fibres such as steel, polypropylene, glass and polyester were commonly used in concrete. In the present study, the effect of adding crimped polypropylene fibres on the improvement in the compressive properties of hardened concrete was studied. Crimped polypropylene fibres with different levels of reinforcements index was investigated systematically with designed concrete m...

  10. 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....

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

    Directory of Open Access Journals (Sweden)

    Sudhir Kumar Saw

    2009-11-01

    Full Text Available 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 composites have been studied. The role of fibre/matrix interactions in chemically modified hybrid composites were investigated using Differential Scanning Calorimeter, Differential Thermo Gravimetry, and a Universal Tensile Machine and compared with those of unmodified bagasse fibre bundles incorporated with modified jute fibre bundles reinforced hybrid composites. Fibre surface modification reduced the hydrophilicity of fibre bundles, and significantly increased mechanical properties of hybrid composites were observed in conjunction with SEM images. The SEM analysis of the fibre and the composite fractured surfaces have confirmed the FA grafting and shown a better compatibility at the interface between chemically modified fibre bundles and epoxy resin. This paper incorporates interesting results of thermomechanical properties and evaluation of fibre/matrix interactions.

  12. 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

  13. 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....

  14. Modelling the side impact of carbon fibre tubes

    International Nuclear Information System (INIS)

    Metallic tubes have been extensively studied for their crashworthiness as they closely resemble automotive crash rails. Recently, the demand to improve fuel economy and reduce vehicle emissions has led automobile manufacturers to explore the crash properties of light weight materials such as fibre reinforced polymer composites, metallic foams and sandwich structures in order to use them as crash barriers. This paper discusses the response of carbon fibre reinforced polymer (CFRP) tubes and their failure mechanisms during side impact. The energy absorption of CFRP tubes is compared to similar Aluminium tubes. The response of the CFRP tubes during impact was modelled using Abaqus finite element software with a composite fabric material model. The material inputs were given based on standard tension and compression test results and the in-plane damage was defined based on cyclic shear tests. The failure modes and energy absorption observed during the tests were well represented by the finite element model.

  15. The application of transient thermography for the thermal characterisation of carbon fibre/epoxy composites

    Directory of Open Access Journals (Sweden)

    G. Wróbel

    2009-09-01

    Full Text Available Purpose: Primary purpose of the present experimental study was to evaluate the local fibre content in carbon fibre/epoxy composites using transient thermography.Design/methodology/approach: The experiments have been performed using transient thermography to obtain the thermograms for carbon/epoxy specimens with different carbon fibre content. From obtained thermograms the thermal diffusivity values were determined and compared for each specimen and correlated with carbon content. The composites were two times tested using two different heating conditions to check the conformity of determined diffusivity values.Findings: It was found from obtained results that composites with different carbon fibre content had different values of thermal diffusivity, indicating that transient thermography can be considered as a non-destructive testing method for fiber content evaluation in CFRP composites.Research limitations/implications: Developed empirical formula is not universal for any other fibre reinforced polymer composite, so different relationships should be determined for different composites.Practical implications: The results obtained from present experiment would be of great importance in the industrial applications to obtain first estimate of carbon fibre content in fibre reinforced composite materials.Originality/value: The originality of present investigation is in application of transient thermography for local fibre content evaluation in polymer composite materials. The method should be of interest for the industrial quality control applications and is of great importance for composite products with high failure-free requirements.

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

    Indian Academy of Sciences (India)

    S Jayabal; U Natarajan

    2011-12-01

    An investigation has been carried out to make use of coir, a natural fibre abundantly available in India. Coir–polyester composites were prepared and their mechanical and machinability characteristics were studied. The short coir–fibre-reinforced composites exhibited the tensile, flexural and impact strength of 16.1709 MPa, 29.2611 MPa and 46.1740 J/m, respectively. The regression equations were developed and optimized for studying drilling characteristics of coir–polyester composites using the Taguchi approach. A drill bit diameter of 6 mm, spindle speed of 600 rpm and feed rate of 0.3 mm/rev gave the minimum value of thrust force, torque and tool wear in drilling analysis.

  17. 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.

  18. Development of fibre reinforced concrete overpacks in France

    International Nuclear Information System (INIS)

    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. Natural fibres-based polymers: Part I—Mechanical analysis of Pine needles reinforced biocomposites

    Indian Academy of Sciences (India)

    Vijay Kumar Thakur; A S Singha

    2010-06-01

    Lack of resources and increasing environmental pollution has evoked great interest in the research of materials that are friendly to our health and environment. Polymer composites fabricated from natural fibres is currently the most promising area in polymer science. Keeping in view the various advantages of natural fibres, in current series of green composites a study on natural fibre reinforced polymer composites has been made. This paper presents the results of an experimental series designed to assess the possibility of Pine needles as reinforcing material in polymer composites. First of all, urea–formaldehyde resin was synthesized and optimized by evaluating its mechanical properties. Optimized resin was reinforced with employing Pine needles of different dimensions such as particle reinforcement, short fibre reinforcement and long fibre reinforcement. Experimental results obtained shows that mechanical properties such as tensile strength, compressive strength and wear resistance of UF resin increases to a considerable extent when reinforced with Pine needles. Further it has been observed that particle reinforcement is more effective as compared to short fibre and long fibre reinforcement. These results suggest that Pine needles can be potential candidates for use in natural fibre reinforced polymer composites. Thermal and morphological studies of these composites have also been carried out.

  20. Strength Modeling of High-Strength Concrete with Hybrid Fibre Reinforcement

    Directory of Open Access Journals (Sweden)

    A. Ravichandran

    2009-01-01

    Full Text Available The low tensile strength and limited ductility, the unavoidable deficiency, of concrete can be overcome by the addition of fibres. High strength concrete (HSC of 60 MPa containing hybrid fibres, combination of steel and polyolefin fibres, at different volume fraction of 0.5, 1.0, 1.5 and 2.0% were compared in terms of compressive, splitting tensile strength and flexural properties with HSC containing no fibres. Test results showed that the fibres when used in hybrid form could result in enhanced flexural toughness compared to steel fibre reinforced concrete [HSFRC]. The compressive strength of the fibre-reinforced concrete reached maximum at 1.5% volume fractions and the splitting tensile strength and modulus of rupture improved with increasing volume fraction. Strength models were established to predict the compressive and splitting tensile strength and modulus of rupture of the fibre-reinforced concrete. The models give prediction matching the measurements.

  1. 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.

  2. 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.

  3. The new structure of fibre glass reinforced plastics bolt

    Institute of Scientific and Technical Information of China (English)

    马念杰; 刘社育

    2003-01-01

    The develop actuality and direction of FRP(fibre glass reinforced plastics) bolt in the world are analyzed. The new type structure of FRP bolt was designed. Trial data indicate that, all kinds of capability target of this FRP bolt all achieve and exceed the country standard, substitute present metal bolt,wood bolt and bamboo bolt and other side bolt, it can gain magnitude technology and economy benefit. FRP bolt mechanization product line produce efficiency is high, its throughput a day are 750 base, this can meet demand of hit-small mining company.

  4. Glass fibre reinforced cement based composite: fatigue and fracture parameters

    Directory of Open Access Journals (Sweden)

    Seitl S.

    2009-12-01

    Full Text Available This paper introduces the basic fracture mechanics parameters of advanced building material – glass fibres reinforced cement based composite and its fracture and fatigue behaviour is investigated. To this aim three-point bend (3PB specimens with starting notch were prepared and tested under static (l–d diagram and cyclic loading (Paris law and Ẅöhler curve. To evaluate the results, the finite element method was used for estimation of the corresponding values of stress intensity factor for the 3PB specimen used. The results obtained are compared with literature data.

  5. Relation between fibre distribution and post-cracking behaviour in steel fibre reinforced self-compacting concrete panels

    OpenAIRE

    Abrishambaf, Amin; Barros, Joaquim A. O.; Cunha, Vitor M. C. F.

    2013-01-01

    In this research, the influence of the fibre distribution and orientation on the post-cracking behaviour of steel fibre 14 reinforced self-compacting concrete (SFRSCC) panels was studied. To perform this evaluation, SFRSCC panels 15 were cast from their centre point. For each SFRSCC panel, cylindrical specimens were extracted and notched either 16 parallel or perpendicular to the concrete flow direction, in order to evaluate the influence of fibre dispersion and 17 orientation on ...

  6. 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

    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...

  7. Blast impact behaviour of concrete with different fibre reinforcement

    Science.gov (United States)

    Drdlová, Martina; Čechmánek, René; Řídký, Radek

    2015-09-01

    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.

  8. The investigation on strength and flexural toughness of fibre cocktail reinforced self-compacting high performance concrete

    OpenAIRE

    Ding Yining; Zhang Yulin; Thomas, A.

    2009-01-01

    Based on the experimental results of the workability, the suitable fibre types (steel fibres, PP-fibres and fibre cocktail) and fibre dosages for fibre-reinforced-self-compacting-high-performance-concrete (FRSCHPC) were selected. To assess the influences of different fibres on the compressive strength, flexural toughness and failure patterns of beams and slabs, a series of experiments has been carried out and evaluated. The results show that the fibre cocktail – a combination of stee...

  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 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

  11. Synthesis of unsaturated polyesters for improved interfacial strength in carbon fibre composites

    DEFF Research Database (Denmark)

    Gamstedt, E.K.; Skrifvars, M.; Jacobsen, T. K.;

    2002-01-01

    Carbon fibres are gaining use as reinforcement in glass fibre/polyester composites for increased stiffness as a hybrid composite. The mechanics and chemistry of the carbon fibre–polyester interface should be addressed to achieve an improvement also in fatigue performance and off-axis strength. To...... make better use of the versatility of unsaturated polyesters in a carbon fibre composite, a set of unsaturated polyester resins have been synthesized with different ratios of maleic anhydride, o-phthalic anhydride and 1,2-propylene glycol as precursors. The effective interfacial strength was determined...... by micro-Raman spectroscopy of a single-fibre composite tested in tension. The interfacial shear strength with untreated carbon fibres increased with increasing degree of unsaturation of the polyester, which is controlled by the relative amount of maleic anhydride. This can be explained by a...

  12. Large waste containers made of fibre reinforced concrete

    International Nuclear Information System (INIS)

    The production of large-sized metallic waste by dismantling operations, and the evolution of the specifications on the waste to be stored in the different European countries will create a need for large standard containers for the transport and final disposal of the corresponding waste. The research conducted during the 1984/1988 programme, supported by the Commission of European Communities, and based on a comparative study of high-grade concrete materials, reinforced with organic or metallic fibres, led to the development of a high performance container meeting international transport recommendations as well as French requirements for shallow-ground disposal. The material selected, consisting of high-performance mortar with metal fibre reinforcement, was the subject of an intensive programme of characterization tests conducted in close cooperation with LaFarge Company, demonstrating the achievement of mechanical and physical properties comfortably above the regulatory requirements. The construction of an industrial prototype and the subsequent economic analysis served to guarantee the industrial feasibility and cost of this system, in which attempts were made to optimize the 'finished package' product, including its closure system. (author)

  13. 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;

    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 with...... real behaviour of the self-compacting fibre reinforced concrete....

  14. Impact of electrochemical cycling on the tensile properties of carbon fibres for structural lithium-ion composite batteries

    OpenAIRE

    Jacques, Eric; Kjell, Maria H.; Zenkert, Dan; Lindbergh, Göran; Behm, Mårten; Willgert, Markus

    2012-01-01

    Carbon fibres are particularly well suited for use in a multifunctional lightweight design of a structural composite material able to store energy as a lithium-ion battery. The fibres will in this case act as both a high performance structural reinforcement and one of the battery electrodes. However, the electrochemical cycling consists of insertions and extractions of lithium ions in the microstructure of carbon fibres and its impact on the mechanical performance is unknown. This study inves...

  15. The usability of recycled carbon fibres in short fibre thermoplastics: interfacial properties

    OpenAIRE

    Burn, D.T.; Harper, Lee Thomas; Johnson, M.; Warrior, N. A.; Nagel, U.; Yang, L.; Thomason, J.

    2016-01-01

    The objective of this study was to investigate the feasibility of combining discontinuous recycled carbon fibres with polypropylene, to produce a low-cost, high specific stiffness material for high-volume applications. The inherent low affinity of carbon fibre and polypropylene motivated a detailed study of the surface characteristics of carbon fibre and interfacial behaviour between the two materials, using the microbond test. The effects of removing the sizing from the fibres, as well as in...

  16. Mechanical Behaviour under Tensile Loading of Textile Reinforced Concrete with Short Fibres

    OpenAIRE

    Barhum, Rabea; Mechtcherine, Viktor

    2011-01-01

    This treatise addresses the influence of the addition of short dispersed and integral fibres made of alkali-resistant glass on the fracture behaviour of textile-reinforced concrete (TRC). A series of uniaxial, deformation-controlled tension tests was performed to study the strength-, deformation-, and fracturebehaviour of thin, narrow plates made of TRC both with and without the addition of short fibres. Furthermore, uniaxial tension tests on specimens reinforced with only short fibres and si...

  17. Adsorption of dyes by ACs prepared from waste tyre reinforcing fibre. Effect of texture, surface chemistry and pH.

    Science.gov (United States)

    Acevedo, Beatriz; Rocha, Raquel P; Pereira, Manuel F R; Figueiredo, José L; Barriocanal, Carmen

    2015-12-01

    This paper compares the importance of the texture and surface chemistry of waste tyre activated carbons in the adsorption of commercial dyes. The adsorption of two commercial dyes, Basic Astrazon Yellow 7GLL and Reactive Rifafix Red 3BN on activated carbons made up of reinforcing fibres from tyre waste and low-rank bituminous coal was studied. The surface chemistry of activated carbons was modified by means of HCl-HNO3 treatment in order to increase the number of functional groups. Moreover, the influence of the pH on the process was also studied, this factor being of great importance due to the amphoteric characteristics of activated carbons. The activated carbons made with reinforcing fibre and coal had the highest SBET, but the reinforcing fibre activated carbon samples had the highest mesopore volume. The texture of the activated carbons was not modified upon acid oxidation treatment, unlike their surface chemistry which underwent considerable modification. The activated carbons made with a mixture of reinforcing fibre and coal experienced the largest degree of oxidation, and so had more acid surface groups. The adsorption of reactive dye was governed by the mesoporous volume, whilst surface chemistry played only a secondary role. However, the surface chemistry of the activated carbons and dispersive interactions played a key role in the adsorption of the basic dye. The adsorption of the reactive dye was more favored in a solution of pH 2, whereas the basic dye was adsorbed more easily in a solution of pH 12. PMID:26295195

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

    International Nuclear Information System (INIS)

    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.

  19. The influence of the Ni layer covering carbon fibre on the AK132 matrix structure

    OpenAIRE

    A. Zyska; Z. Konopka; M. Łągiewka

    2007-01-01

    The quality and the quantity assessment of the structure of the AlSi13Cu2 alloy matrix composites reinforced with carbon fibre in the amount of 5, 10, or 15 vol. percent has been presented. Due to the poor wettability of carbon fibre by molten AlSi alloy and the low castability of the examined composites, the Ni-covered fibre with 0.25 μm thick Ni layer has been used and the pressure casting technology has been employed. The chemical interaction between Ni layer and the molten AlSi alloy has ...

  20. The Efficiency of Basalt Fibres in Strengthening the Reinforced Concrete Beams

    OpenAIRE

    Andreea Şerbescu; Pilakoutas Kypros; N. Ţăranu

    2006-01-01

    The technique of externally bonding fibre reinforced polymer (FRP) composite laminates on the tension side of reinforced concrete (RC) beams is already widely accepted as an easy to apply, corrosion resistant and effective solution due to the high strength as well as the low weight of the composite material. The basalt fibres are produced from volcano rocks by a simple process; their applicability as reinforcing material composites utilized for plate bonding of RC beams was not enough researc...

  1. Steel fibre reinforced self-compacting concrete (from micromechanics to composite behavior)

    OpenAIRE

    Cunha, Vitor M. C. F.

    2010-01-01

    Tese de Doutoramento em Engenharia Civil The use of steel fibre reinforced self-compacting concrete, SFRSCC, probably, will swiftly increase in the next years, since this composite material introduces several advantages on the concrete technology. In fact, the partial or total replacement of the conventional bar reinforcement by discrete fibres optimizes the construction process. The assembly of the reinforcement bars in the construction of concrete structures has a significant economical ...

  2. Evaluation on mechanical properties of woven aloevera and sisal fibre hybrid reinforced epoxy composites

    Indian Academy of Sciences (India)

    A Shadrach Jeya Sekaran; K Palani Kumar; K Pitchandi

    2015-09-01

    Natural fibres as reinforcement in polymer composite for making low-cost materials are growing day by day. Researcher’s main attention is to apply appropriate technology to utilize these natural fibres as effectively and economically as possible to produce good quality fibre-reinforced polymer composites for various engineering applications. In this research, the experiments of tensile, flexural and impact tests were carried out for woven aloevera and sisal fibre hybrid-reinforced epoxy composites. The hand layup method of fabrication was employed in preparing the composites. The surface morphology of the composites was examined through scanning electron microscope. Due to the low-density and high-specific properties of sisal fibre composites, it offer cost savings when compared with synthetic fibres. Hence it has very good implications in the automotive and transportation industry.

  3. Parametric Study of End Milling Glass Fibre Reinforced Composites

    International Nuclear Information System (INIS)

    This paper discusses the application of Taguchi 'Design of Experiment' method to investigate the effects of end milling parameters on machinability characteristics of unidirectional E-glass fibre reinforced polymer (GFRP) composites. A series of milling experiments were conducted using tungsten carbide end milling cutters at various spindle speeds, feed rates and depths of cut. Taguchi analysis was carried out and the signal to noise (S/N) ratio with analysis of variance (ANOVA) was employed to analyse the effects of those parameters on GFRP machinability. Overall, the results of the current investigations present some desirable combinations of the machining parameters that can further enhance the end milling machinability characteristics to suit the final requirements of the finished GFRP products.

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

    Science.gov (United States)

    Croitoru, Catalin; Patachia, Silvia; Papancea, Adina; Baltes, Liana; Tierean, Mircea

    2015-12-01

    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.

  5. Parametric Study of End Milling Glass Fibre Reinforced Composites

    Science.gov (United States)

    Azmi, Azwan I.; Lin, Richard J. T.; Bhattacharyya, Debes

    2011-01-01

    This paper discusses the application of Taguchi `Design of Experiment' method to investigate the effects of end milling parameters on machinability characteristics of unidirectional E-glass fibre reinforced polymer (GFRP) composites. A series of milling experiments were conducted using tungsten carbide end milling cutters at various spindle speeds, feed rates and depths of cut. Taguchi analysis was carried out and the signal to noise (S/N) ratio with analysis of variance (ANOVA) was employed to analyse the effects of those parameters on GFRP machinability. Overall, the results of the current investigations present some desirable combinations of the machining parameters that can further enhance the end milling machinability characteristics to suit the final requirements of the finished GFRP products.

  6. Unidirectional Cordenka Fibre-Reinforced Furan Resin Full Biocomposite: Properties and Influence of High Fibre Mass Fraction

    Directory of Open Access Journals (Sweden)

    Talent Malaba

    2015-01-01

    Full Text Available A full biocomposite was fabricated from Cordenka CR fibre and furan resin. High fibre mass fractions (FMF were achieved by pressing the CR fibres into unidirectional sheets prior to incorporation into the resin. Results of testing indicated that the tensile properties of the biocomposite were improved by the initial increase of FMF from 51 to 64%, with a subsequent increase of FMF to 75% resulting in a deterioration of those properties. Examination of the tensile fracture surfaces with a scanning electron microscope (SEM revealed moderate deterioration in fibre-matrix adhesion after the initial increase of FMF. Further increase of the FMF to 75% was shown by SEM to result in worse fibre-matrix adhesion. On the other hand, the flexural, interlaminar-shear, and dynamic mechanical properties were adversely affected by the increase in fibre-mass fraction from 51 through 75%. These effects were mainly attributed to reduced fibre wetting that resulted in weakened fibre-matrix interfacial bonding and subsequent poor stress exchange at the fibre-matrix interface. Observations made with a digital microscope revealed normal crack behaviour in the laminated composite, and the shear fracture modes were I and II. This biocomposite has mechanical properties comparable to those of flax and glass fibre-reinforced furan resin biocomposites.

  7. 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.

  8. Mechanical and electrical performance of Roystonea regia/glass fibre reinforced epoxy hybrid composites

    Indian Academy of Sciences (India)

    Govardhan Goud; R N Rao

    2012-08-01

    The present paper investigates mechanical and electrical properties of Roystonea regia/glass fibre reinforced epoxy hybrid composites. Five varieties of hybrid composites have been prepared by varying the glass fibre loading. Roystonea regia (royal palm), a natural fibre was collected from the foliage of locally available royal palm tree through the process of water retting and mechanical extraction. Roystonea regia, -glass short fibres were used together as reinforcement in epoxy matrix to form hybrid composites. It has been observed that tensile, flexural, impact and hardness properties of hybrid composites considerably increased with increase in glass fibre loading. But electrical conductivity and dielectric constant values decreased with increase in glass fibre content in the hybrid composites at all frequencies. Scanning electron microscopy of fractured hybrid composites has been carried out to study the fibre matrix adhesion.

  9. Short Fibre and Particulate-reinforced Rubber Composites

    Directory of Open Access Journals (Sweden)

    Kavita Agarwal

    2002-07-01

    Full Text Available Particulate fillers (carbon black and silica and short fibre (aromatic polyamide, Kevlar have been utilised to produce rubber composites based on acrylonitrile-co-butadiene rubber (NBR. Mechanical properties of these composites have been determined and compared with unfilled rubber vulcanisate. The effect of surface treatment on the improvement of strength, in case of Kevlar, has also been considered. The influence of elevated temperature on tear strength, an important failure criterion, has been evaluated. Scanning electron microscopy has been used as a tool to correlate the topographical features associated with changes in the tear strength of the composites.

  10. Microstructure and mechanical performance of modified mortar using hemp fibres and carbon nanotubes

    KAUST Repository

    Hamzaoui, Rabah

    2014-04-01

    Mechanical performance of modified mortar using hemp fibres is studied following various processing conditions. Hemp fibres combined with carbon nanotubes (CNT) are introduced in mortar and their effect is studied as function of curing time. The cement phase is replaced by different percentages of dry or wet hemp fibres ranging from 1.1. wt% up to 3.1. wt% whereas carbon nanotubes are dispersed in the aqueous solution. Our experimental results show that compressive and flexural strengths of wet fibres modified mortar are higher than those for dry hemp-mortar material. The achieved optimal percentage of wet hemp fibres is 2.1. wt% allowing a flexural strength higher than that of reference mortar. The addition of an optimal CNT concentration (0.01. wt%) combined with wet hemp has a reinforcing effect which turns to be related to an improvement of compressive and flexural strengths by 10% and 24%, respectively, in comparison with reference condition. © 2013 Elsevier Ltd.

  11. 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.

  12. Consolidation modeling of fibre reinforced thermoplastic composite materials

    International Nuclear Information System (INIS)

    Thermoplastic matrix composites offer rapid, clean processing compared to their thermoset counterparts. In automotive applications they also provide useful toughness and recyclability. Recent developments in co- mingling technology consisting of uniform combination of reinforcement and matrix have provided a new hybrid yam which facilitates a range of fabrication options combined with the potential for relatively low pressure processing. Both isothermal and non-isothermal compression moulding processes have successfully been used to produce thermoplastic composite materials while maintaining various process parameters. These process parameters including mainly pressure and temperature have a major influence on the final quality of the component including void content due to high melt viscosity of thermoplastic. A mathematical model has been developed and described in this paper that monitors these process parameters and their effect on the quality of the composite material. The results thus obtained were compared with the experimental results obtained by making flat plaques and tubular parts. Co-mingled material used during the experimental and modeling consisted of glass fibre as a reinforcement and polypropylene as the matrix. (author)

  13. The potential of using date palm fibres as reinforcement for polymeric composites

    International Nuclear Information System (INIS)

    Highlights: ► High concentration of chemical treatment may deteriorate the natural fibre strength. ► Fibre length in the composite significantly influences the interfacial adhesion property. ► 6% NaOH treatment is the optimum concentration to treat the natural fibres. ► Chemical treatment enhances the surface characteristics of the fibres. ► Chemical treatment reduces the porosity of the composites. -- Abstract: Interfacial adhesion of natural fibres as reinforcement for fibre polymeric composites is the key parameter in designing composites. In the current study, interfacial adhesion of date palm fibre with epoxy matrix is experimentally investigated using single fibre pull out technique. The influence of NaOH treatment concentrations (0–9%), fibre embedded length and fibre diameter on the interfacial adhesion property was considered in this study. Scanning Electron Microscopy (SEM) was used to observe the surface morphology and damage feature on the fibre and bonding area before and after conducting the experiments. The results revealed that 6% concentration of NaOH is the optimum solution for treating the date palm fibre to maintain high interfacial adhesion and strength with epoxy matrix. The embedded length of the fibre controlled the interfacial adhesion property, where 10 mm embedded length was the optimum fibre length.

  14. Wear mechanisms of fibre reinforced composite materials based on 2024 and 7075 aluminum alloys

    Directory of Open Access Journals (Sweden)

    K. Naplocha

    2011-12-01

    Full Text Available Purpose: Determination of fibre reinforcement influence on wear rate and wear mechanisms were examined. Moreover, effect of fibre orientation and specimen pressure on the counterpart were analyzed.Design/methodology/approach: Composite materials based on 2024 and 7075 aluminium alloys were reinforced with 10-20 vol. % of alumina Saffil fibres and additionally choosen specimens with graphite fibres. Wear tests were carried out on pin-on-disc device where the specimens were pressed to the cast iron counterpart with forces corresponding to pressures of 0.8, 1.2 and 1.5 MPa.Findings: Wear mass loss for composite materials reinforced only with Saffil Al2O3 fibres decreased with increase of fibre content in the matrix. The largest wear rate in relation to the unreinforced alloy exhibited composites containing 20 vol. % of Saffil Al2O3 fibres, tested under the largest applied pressure of 1.5 MPa. The graphite fibres enhance the wear resistance of composite materials under all applied pressures. The lubricant medium originated form worn graphite fibres prevented composite from seizure and adhesive wear.Research limitations/implications: Fragmented alumina fibres acting as loose debris can enhance the wear rate both composite and iron counterpart. At high volume of graphite fibres produced preform possess low strength caused by weak joints between fibres.Practical implications: Composite 2024 and 7075 materials reinforced with hybrid preforms produced from alumina and graphite fibres exhibit good wear resistance.Originality/value: Manufactured composite materials will be considered as the friction materials for the high duty brakes.

  15. Mechanical properties of kenaf bast and core fibre reinforced unsaturated polyester composites

    Energy Technology Data Exchange (ETDEWEB)

    Ishak, M R; Leman, Z; Sapuan, S M [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Edeerozey, A M M; Othman, I S, E-mail: zleman@eng.upm.edu.my [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, 76109 Durian Tunggal, Melaka (Malaysia)

    2010-05-15

    Kenaf fibre has high potential to be used for composite reinforcement in biocomposite material. It is made up of an inner woody core and an outer fibrous bark surrounding the core. The aim of this study was to compare the mechanical properties of short kenaf bast and core fibre reinforced unsaturated polyester composites with varying fibre weight fraction i.e. 0%, 5%, 10%, 20%, 30% and 40%. The compression moulding technique was used to prepare the composite specimens for tensile, flexural and impact tests in accordance to the ASTM D5083, ASTM D790 and ASTM D256 respectively. The overall results showed that the composites reinforced with kenaf bast fibre had higher mechanical properties than kenaf core fibre composites. The results also showed that the optimum fibre content for achieving highest tensile strength for both bast and core fibre composites was 20%wt. It was also observed that the elongation at break for both composites decreased as the fibre content increased. For the flexural strength, the optimum fibre content for both composites was 10%wt while for impact strength, it was at 10%wt and 5%wt for bast and core fibre composites respectively.

  16. Mechanical properties of kenaf bast and core fibre reinforced unsaturated polyester composites

    Science.gov (United States)

    Ishak, M. R.; Leman, Z.; Sapuan, S. M.; Edeerozey, A. M. M.; Othman, I. S.

    2010-05-01

    Kenaf fibre has high potential to be used for composite reinforcement in biocomposite material. It is made up of an inner woody core and an outer fibrous bark surrounding the core. The aim of this study was to compare the mechanical properties of short kenaf bast and core fibre reinforced unsaturated polyester composites with varying fibre weight fraction i.e. 0%, 5%, 10%, 20%, 30% and 40%. The compression moulding technique was used to prepare the composite specimens for tensile, flexural and impact tests in accordance to the ASTM D5083, ASTM D790 and ASTM D256 respectively. The overall results showed that the composites reinforced with kenaf bast fibre had higher mechanical properties than kenaf core fibre composites. The results also showed that the optimum fibre content for achieving highest tensile strength for both bast and core fibre composites was 20%wt. It was also observed that the elongation at break for both composites decreased as the fibre content increased. For the flexural strength, the optimum fibre content for both composites was 10%wt while for impact strength, it was at 10%wt and 5%wt for bast and core fibre composites respectively.

  17. Mechanical properties of kenaf bast and core fibre reinforced unsaturated polyester composites

    International Nuclear Information System (INIS)

    Kenaf fibre has high potential to be used for composite reinforcement in biocomposite material. It is made up of an inner woody core and an outer fibrous bark surrounding the core. The aim of this study was to compare the mechanical properties of short kenaf bast and core fibre reinforced unsaturated polyester composites with varying fibre weight fraction i.e. 0%, 5%, 10%, 20%, 30% and 40%. The compression moulding technique was used to prepare the composite specimens for tensile, flexural and impact tests in accordance to the ASTM D5083, ASTM D790 and ASTM D256 respectively. The overall results showed that the composites reinforced with kenaf bast fibre had higher mechanical properties than kenaf core fibre composites. The results also showed that the optimum fibre content for achieving highest tensile strength for both bast and core fibre composites was 20%wt. It was also observed that the elongation at break for both composites decreased as the fibre content increased. For the flexural strength, the optimum fibre content for both composites was 10%wt while for impact strength, it was at 10%wt and 5%wt for bast and core fibre composites respectively.

  18. 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 until...... 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...

  19. 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.

  20. 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.

  1. In vitro degradation of porous nano-hydroxyapatite/collagen/PLLA scaffold reinforced by chitin fibres

    International Nuclear Information System (INIS)

    In this paper, a novel porous scaffold for bone tissue engineering was prepared with nano-hydroxyapatite/collagen/Poly-L-lactic acid (PLLA) composite reinforced by chitin fibres. To enhance the strength of the scaffold further, PLLA was linked with chitin fibres by Dicyclohexylcarbodimide (DCC). The structures of the reinforced scaffold with and without linking were characterized by Scanning Electron Microscopy (SEM). The chemical characteristics of the chitin fibres with and without linking were evaluated by Fourier-transformed infrared (FTIR) spectroscopy. The mechanical performance during degradation in vitro was investigated. The results indicated that the nano-hydroxyapatite/collagen/PLLA composite reinforced by chitin fibres with linking kept better mechanical properties than that of the composite without linking. These results denoted that the stronger interfacial bonding strength of the scaffold with linking could decrease the degradation rate in vitro. The reinforced composite with the link-treatment can be severed as a scaffold for bone tissue engineering

  2. 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

  3. Effects on the Thermo-Mechanical and Crystallinity Properties of Nylon 6,6 Electrospun Fibres Reinforced with One Dimensional (1D and Two Dimensional (2D Carbon

    Directory of Open Access Journals (Sweden)

    Francisco Medellín-Rodríguez

    2013-08-01

    Full Text Available Electrospun one dimensional (1D and two dimensional (2D carbon based polymer nanocomposites are studied in order to determine the effect provided by the two differently structured nanofillers on crystallinity and thermo-mechanical properties of the nanofibres. The nanomaterials studied are pristine carbon nanotubes, oxidised carbon nanotubes, reduced graphene oxide and graphene oxide. Functional groups associated with the order structure of the polymers are analysed by infrared and Raman spectroscopies; the morphology is studied by scanning electron microscopy and the crystallinity properties are investigated by differential scanning calorimetry and X-ray diffraction. Differences in crystallisation behaviour between 1D and 2D carbon based nanofibres are shown by their crystallinity degree and their crystal sizes. The nanocomposite crystal sizes perpendicular to the plane (100 decrease with nanofiller content in all cases. The crystallinity trend and crystal sizes are in accordance with storage modulus response. The results also suggest that functionalisation favours interfacial bonding and dispersion of the nanomaterials within the polymer matrix. As a consequence the number of nucleating sites increases which in turn decreases the crystal size in the nanocomposites. These features explain the improved thermo-mechanical properties in the nanocomposites.

  4. Surveillance of steel fibre reinforced concrete slabs measured with an open-ended coaxial probe

    OpenAIRE

    Torrents Dolz, Josep M.; Juan Garcia, Pablo; Patau, Oriol; Aguado de Cea, Antonio

    2009-01-01

    Conventional concrete structures are nowadays being substituted by steel fibre reinforced concrete (SFRC) in some structural applications. Then, fibre dosage and distribution is a keyword for ensuring quality control of structures. The present work analyses the possibility of an Open Ended Coaxial Probe as an element for ensuring the quality of a concrete slices.

  5. Influence of Alkali Treatment and Fibre Content on the Properties of Oil Palm Press Fibre Reinforced Epoxy Biocomposites

    Directory of Open Access Journals (Sweden)

    Obasi H.C

    2016-07-01

    Full Text Available In the present work, oil palm press fibre reinforced epoxy composites were developed. The effect of fibre loading varying from 5 wt. % to 30 wt. % on the mechanical properties of oil palm press fibre/epoxy composite was studied. The effect of alkali treatment on mechanical properties of the composites was also investigated. The mechanical properties of treated OPPF/epoxy composites were found to be higher that the untreated oil palm press fibres. Optimum tensile, flexural and impact strengths of OPPF/epoxy composites were obtained at fibre content of 20 wt. % in this work. Hardness, tensile strength and modulus of the composites increased with increasing fibre loading. Alkali-treated OPPF/epoxy composites when compared with untreated OPP fibres at 20 wt.% fibre loading showed an increase of tensile strength by 18.79 %, flexural strength by 15.15 % and impact strength by 18.21 %. The removal of hemicelluloses and other impurities with alkali treatment resulting to higher crystallinity of the OPPF could be responsible for these observations.

  6. Localised low velocity impact performance of short glass fibre reinforced polyamide 66 oil pans

    OpenAIRE

    Mouti, Zakaria

    2012-01-01

    This thesis focuses on the mechanical properties of short glass fibre reinforced polyamide 66 material used in automotive composite structures, and its impact resistance under localised low velocity impact. The main application of this research concerns the impact performance of an oil pan component susceptible to stone impact damage. The thesis reviews the current state-of-the-art of thermoplastic polyamide materials with an overview of the glass fibre reinforced polyamide ...

  7. Effect of filler addition on the compressive and impact properties of glass fibre reinforced epoxy

    Indian Academy of Sciences (India)

    Nikhil Gupta; Balraj Singh Brar; Eyassu Woldesenbet

    2001-04-01

    Flyash is incorporated in glass fibre reinforced epoxies to study their response to the filler addition. Low cost of flyash can reduce the overall cost of the component. Only very low volume fractions of filler are investigated in the present study. To obtain further clarification of the observed phenomenon, another abundantly available low cost material, calcium carbonate is incorporated in one set of the specimens. Compressive strength of the material is found to decrease, whereas steep increase in impact strength is observed by introduction of very small quantity of fillers. Specimens containing calcium carbonate are tested for impact properties only. Effect of specimen aspect ratio on the compressive strength values is also studied by testing specimens of three different aspect ratios. Scanning electron microscopic observations are taken to develop a better understanding of the phenomena taking place in the material system at microscopic level.

  8. Influence of steady shear flow on dynamic viscoelastic properties of un-reinforced and Kevlar, glass fibre reinforced LLDPE

    Indian Academy of Sciences (India)

    Takeshi Kitano; S A R Hashmi; Navin Chand

    2004-10-01

    An experimental study was conducted to observe the effects of parallel-superposed flow condition on viscoelastic properties of LLDPE, Kevlar fibre reinforced LLDPE and hybrid of short glass fibre and Kevlar fibre reinforced LLDPE. Parallel-plate rheometer was employed for these tests. Rheological parameters such as loss modulus (″) and dynamic viscosity (′) do not vary significantly on superposing steady state shear with oscillatory shear in the studied range of experiment at 185°C in un-reinforced LLDPE. Kevlar fibre reinforced LLDPE and Kevlar/glass fibre reinforced LLDPE showed significant changes in the flow behaviour under various sets of superposed conditions. Storage modulus (′), and ″ become highly sensitive to low oscillatory angular frequencies () under superposed conditions. These curves show two different regions with increased value. At low values, parameters ′ and ″ change sharply reaching a certain value, thereafter, changes are moderate with increased . In case of ′ a maxima is observed, position of which, depends upon the value of steady shear rate. Maxima shifts towards higher frequencies with the increased steady shear rate.

  9. A Progressive Damage Model for unidirectional Fibre Reinforced Composites with Application to Impact and Penetration Simulation

    Science.gov (United States)

    Kerschbaum, M.; Hopmann, C.

    2016-01-01

    The computationally efficient simulation of the progressive damage behaviour of continuous fibre reinforced plastics is still a challenging task with currently available computer aided engineering methods. This paper presents an original approach for an energy based continuum damage model which accounts for stress-/strain nonlinearities, transverse and shear stress interaction phenomena, quasi-plastic shear strain components, strain rate effects, regularised damage evolution and consideration of load reversal effects. The physically based modelling approach enables experimental determination of all parameters on ply level to avoid expensive inverse analysis procedures. The modelling strategy, implementation and verification of this model using commercially available explicit finite element software are detailed. The model is then applied to simulate the impact and penetration of carbon fibre reinforced cross-ply specimens with variation of the impact speed. The simulation results show that the presented approach enables a good representation of the force-/displacement curves and especially well agreement with the experimentally observed fracture patterns. In addition, the mesh dependency of the results were assessed for one impact case showing only very little change of the simulation results which emphasises the general applicability of the presented method.

  10. Polymeric gel electrolytes reinforced with glass-fibre cloth for lithium secondary batteries

    Science.gov (United States)

    Park, Ho Cheol; Chun, Jong Han; Kim, Sang Hern; Ko, Jang Myoun; Jo, Soo Ik; Chung, Jae Sik; Sohn, Hun-Joon

    Polymeric gel electrolytes (PGE), based on polyacrylonitrile blended with poly(vinylidene fluoride-co-hexafluoropropylene) (P(VdF-co-HFP)), which are reinforced with glass-fibre cloth (GFC) to increase the mechanical strength, are prepared for the practical use in lithium secondary batteries. The resulting electrolytes exhibit electrochemical stability at 4.5 V against lithium metal and a conductivity value of (2.0-2.1)×10 -3 S cm -1 at room temperature. The GFC-PGE electrolytes show excellent strength and flexibility when used in batteries even if they contain a plasticiser. A test cell with LiCoO 2 as a positive electrode and mesophase pich-based carbon fibre (MCF) as a negative electrode display a capacity of 110 mAh g -1 based on the positive electrode weight at the 0.2 C rate at room temperature. Over 80% of the initial capacity is retained after 400 cycles. This indicates that GFC is suitable as a reinforcing material to increase the mechanical strength of gel-based electrolytes for lithium secondary batteries.

  11. A Progressive Damage Model for unidirectional Fibre Reinforced Composites with Application to Impact and Penetration Simulation

    Science.gov (United States)

    Kerschbaum, M.; Hopmann, C.

    2016-06-01

    The computationally efficient simulation of the progressive damage behaviour of continuous fibre reinforced plastics is still a challenging task with currently available computer aided engineering methods. This paper presents an original approach for an energy based continuum damage model which accounts for stress-/strain nonlinearities, transverse and shear stress interaction phenomena, quasi-plastic shear strain components, strain rate effects, regularised damage evolution and consideration of load reversal effects. The physically based modelling approach enables experimental determination of all parameters on ply level to avoid expensive inverse analysis procedures. The modelling strategy, implementation and verification of this model using commercially available explicit finite element software are detailed. The model is then applied to simulate the impact and penetration of carbon fibre reinforced cross-ply specimens with variation of the impact speed. The simulation results show that the presented approach enables a good representation of the force-/displacement curves and especially well agreement with the experimentally observed fracture patterns. In addition, the mesh dependency of the results were assessed for one impact case showing only very little change of the simulation results which emphasises the general applicability of the presented method.

  12. Carbon Nanotubes Reinforced Composites for Biomedical Applications

    OpenAIRE

    Wei Wang(College of William and Mary); Yuhe Zhu; Susan Liao; Jiajia Li

    2014-01-01

    This review paper reported carbon nanotubes reinforced composites for biomedical applications. Several studies have found enhancement in the mechanical properties of CNTs-based reinforced composites by the addition of CNTs. CNTs reinforced composites have been intensively investigated for many aspects of life, especially being made for biomedical applications. The review introduced fabrication of CNTs reinforced composites (CNTs reinforced metal matrix composites, CNTs reinforced polymer matr...

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

    International Nuclear Information System (INIS)

    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)

  14. Shock Interaction Studies on Glass Fibre Reinforced Epoxy Matrix Composites

    Science.gov (United States)

    Reddy, K. P. J.; Jagadeesh, G.; Jayaram, V.; Reddy, B. Harinath; Madhu, V.; Reddy, C. Jaya Rami

    Glass fibre reinforced polymer matrix composites are being extensively used for structural applications both in civil and defense sectors, owing to their high specific strength, stiffness and good energy absorbing capability. Understanding the dynamic response of these composites on shock loading is very essential for effective design of structures resistant to blast loads. In the present study, E- glass/epoxy composite laminate has been fabricated and evaluated for their mechanical properties such as tensile strength, flexural strength and inter laminar shear strength (ILSS). Further, dynamic response of E-glass laminates is presently studied by shock loading. When E-glass composite subjected to peak shock reflected pressure of 7.2 MPa and estimated temperature of about 14000 K for short duration, it underwent surface discolorations and charring of epoxy matrix. Post test analysis of the composite sample was carried out to study the damage analysis using Scanning Electron Microscope (SEM), changes in thermal properties of composites using Dynamic Mechanical Analyzer (DMA) and Thermo-Gravimetric Analyzer (TGA). The results of these investigations are discussed in this paper.

  15. 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.

  16. Hybrid type anterior fibre-reinforced composite resin prosthesis: a case report.

    Science.gov (United States)

    Garoushi, Sufyan; Shinya, Akikazu; Shinya, Akiyoshi; Vallittu, Pekka K

    2008-03-01

    A variety of therapeutic modalities, from implant to conventional Maryland prosthesis, can be used for the replacement of a missing anterior tooth. In patients refusing implant treatment, when minimal teeth reduction is preferred, a fibre reinforced composite (FRC) prosthesis can be a good alternative to conventional prosthetic techniques. The purpose of this case report is to describe the clinical procedure for fabricating hybrid type FRC prosthesis with pre-impregnated unidirectional E-glass fibres. Fibre-reinforced composite, in combination with adhesive technology, appears promising treatment option for replacing missing teeth. However, further clinical investigation will be required to provide additional information on this technique. PMID:18468325

  17. 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.

  18. A Study on the Mechanical Properties of Oil Palm Mesocarp Fibre-Reinforced Thermoplastic

    OpenAIRE

    Olusola Femi Olusunmade; Dare Aderibigbe Adetan; Charles Olawale Ogunnigbo

    2016-01-01

    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 car...

  19. Effects of moisture on the mechanical properties of glass fibre reinforced vinylester resin composites

    Indian Academy of Sciences (India)

    Rita Roy; B K Sarkar; N R Bose

    2001-02-01

    Glass fibre reinforced vinylester resin composites incorporating varying amounts of fibres (63.5, 55.75, 48.48, 38.63 and 27.48 wt%) were characterized for their mechanical properties both as prepared and after treatment with boiling water for 2, 4, 6, 8 and 24 h. Weights of the samples were found to increase to a saturation at about 8 h with boiling water treatment. In keeping with the composite principle, the mechanical properties improved with fibre loading. However, the properties were relatively inferior when treated with boiling water for longer hours attributing to ingress of moisture by capillary action through the interface between the fibre and the resin matrix. Considering the rates of moisture absorption and correlating with the mechanical properties, it was observed that the deteriorating effects were predominant up to 4 h treatment with boiling water. Estimation of defect concentrations for 63.5 wt% of nascent fibre reinforced composites as well as those composites treated with boiling water for 24 h were 56.93% and 64.16% respectively. Similarly, 27.48 wt% nascent fibre reinforced composites and those composites with boiling water treatment showed the estimation of defect concentrations of 39.94% and 50.55% respectively. SEM study of the fractured surfaces showed heavy fibre pull-out in the tensile zone whilst shear fracture of the fibre bundles was predominant at the compressive zone of the samples tested for flexural strength properties.

  20. 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.

  1. Effect of sepiolite on the flocculation of suspensions of fibre-reinforced cement

    International Nuclear Information System (INIS)

    Sepiolite is used to increase thixotropy of cement slurries for easier processing, to prevent sagging and to provide a better final quality in the manufacture of fibre-reinforced cement products. However, the effect of sepiolite on flocculation and its interactions with the components of fibre cement are yet unknown. The aim of this research is to study the effects of sepiolite on the flocculation of different fibre-reinforced cement slurries induced by anionic polyacrylamides (A-PAMs). Flocculation and floc properties were studied by monitoring the chord size distribution in real time employing a focused beam reflectance measurement (FBRM) probe. The results show that sepiolite increases floc size and floc stability in fibre-cement suspensions. Sepiolite competes with fibres and clay for A-PAMs adsorption and its interaction with A-PAM improves flocculation of mineral particles.

  2. Catalytic carbon deposition on 3-dimensional carbon fibre supports

    OpenAIRE

    Thornton, Matthew James

    2005-01-01

    Catalytic carbon deposition reactions, using methane, ethane or synthetic natural gas (1.8 vol. % propane, 6.7 vol. % ethane and balance methane) as the carbon-containing gas feedstock with or without the addition of hydrogen, have been investigated over nickel, cobalt and iron catalysts supported on 3-dimensional carbon fibre supports, using both a horizontal tube furnace and an isothermal, isobaric induction furnace. The transition metal catalysts were prepared by impregnating 3-dimens...

  3. 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.

  4. Behaviour of fibre reinforced polymer confined reinforced concrete columns under fire condition

    Science.gov (United States)

    Chowdhury, Ershad Ullah

    In recent years, fibre reinforced polymer (FRP) materials have demonstrated enormous potential as materials for repairing and retrofitting concrete bridges that have deteriorated from factors such as electro-chemical corrosion and increased load requirements. However, concerns associated with fire remain an obstacle to applications of FRP materials in buildings and parking garages due to FRP's sensitivity to high temperatures as compared with other structural materials and to limited knowledge on their thermal and mechanical behaviour in fire. This thesis presents results from an ongoing study on the fire performance of FRP materials, fire insulation materials and systems, and FRP wrapped reinforced concrete columns. The overall goal of the study is to understand the fire behaviour of FRP materials and FRP strengthened concrete columns and ultimately, provide rational fire safety design recommendations and guidelines for FRP strengthened concrete columns. A combined experimental and numerical investigation was conducted to achieve the goals of this research study. The experimental work consisted of both small-scale FRP material testing at elevated temperatures and full-scale fire tests on FRP strengthened columns. A numerical model was developed to simulate the behaviour of unwrapped reinforced concrete and FRP strengthened reinforced concrete square or rectangular columns in fire. After validating the numerical model against test data available in literature, it was determined that the numerical model can be used to analyze the behaviour of concrete axial compressive members in fire. Results from this study also demonstrated that although FRP materials experience considerable loss of their mechanical and bond properties at temperatures somewhat below the glass transition temperature of the resin matrix, externally-bonded FRP can be used in strengthening concrete structural members in buildings, if appropriate supplemental fire protection system is provided over

  5. Tensile and compressive properties of flax fibres for natural fibre reinforced composites

    NARCIS (Netherlands)

    Bos, H.L.; Oever, van den M.J.A.; Peters, O.C.J.J.

    2002-01-01

    Mechanical properties of standard decorticated and hand isolated flax bast fibres were determined in tension as well as in compression. The tensile strength of technical fibre bundles was found to depend strongly on the clamping length. The tensile strength of elementary flax fibres was found to ran

  6. Assessment of microcapsule—catalyst particles healing system in high performance fibre reinforced polymer composite

    Science.gov (United States)

    Bolimowski, P. A.; Wass, D. F.; Bond, I. P.

    2016-08-01

    Autonomous self-healing in carbon fibre reinforced polymer (CFRP) is demonstrated using epoxy resin filled microcapsules and a solid-state catalyst. Microcapsules filled with oligomeric epoxy resin (20–450 μm) and particles of Sc(OTf)3 are embedded in an interleave region of a unidirectional CFRP laminate and tested under mode I loading. Double cantilever beam (DCB) test specimens containing variable concentrations of microcapsules and catalyst were prepared, tested and compared to those healed by manual injection with corresponding healing resin formulation. The healing efficiency was evaluated by comparing the maximum peak load recorded on load–displacement curves for pristine and healed specimens. A 44% maximum recovery was observed for specimens containing 10 wt% of solid phase catalyst and 11 wt% of epoxy microcapsules. However, a significant (80%) decrease in initial strain energy release rate (G IC) was observed for specimens with the embedded healing chemistries.

  7. Shear behaviour of steel fibre reinforced self-consolidating concrete beams based on the modified compression field theory

    OpenAIRE

    Ding, Yining; Zhang Fasheng; Torgal, Fernando Pacheco; Zhang Yulin

    2012-01-01

    A series of steel fibre reinforced self-consolidating concrete (SFRSCC) beams have been tested to investigate the influence of steel fibres and the combined effect of fibres and stirrups on the deflection and cracking, ultimate loads and failure pattern. The experiment indicates that the shear strength increases clearly with the increasing of fibre content. The combination of steel fibres and stirrups demonstrates a positive composite effect on the ultimate load, ductility and fai...

  8. 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

    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 exx......, transversal stress ryy;zz, and non-uniform strain exxðxxÞ, were identified. These damage mechanisms were identified during the experimental testing and linked with the sensor output using a digital image correlation technique. A dedicated algorithm to extract information from the reflected spectrum...

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

    Directory of Open Access Journals (Sweden)

    Sanna Virtanen

    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.

  10. Microwave absorbing properties of activated carbon fibre polymer composites

    Indian Academy of Sciences (India)

    Tianchun Zou; Naiqin Zhao; Chunsheng Shi; Jiajun Li

    2011-02-01

    Microwave absorption of composites containing activated carbon fibres (ACFs) was investigated. The results show that the absorptivity greatly depends on increasing ACF content in the absorbing layer, first increasing and then decreasing. When the content is 0.76 wt.%, the bandwidth below −10dB is 12.2 GHz. Comparing the absorption characteristics of the ACF composite with one containing unactivated fibres, it is found that carbon fibre activation increases the absorption of the composite.

  11. The Efficiency of Basalt Fibres in Strengthening the Reinforced Concrete Beams

    Directory of Open Access Journals (Sweden)

    Andreea Şerbescu

    2006-01-01

    Full Text Available The technique of externally bonding fibre reinforced polymer (FRP composite laminates on the tension side of reinforced concrete (RC beams is already widely accepted as an easy to apply, corrosion resistant and effective solution due to the high strength as well as the low weight of the composite material. The basalt fibres are produced from volcano rocks by a simple process; their applicability as reinforcing material composites utilized for plate bonding of RC beams was not enough researched up to now but it seems to be a cost-effective, durable and fire resistant alternative to traditional fibres. High basalt fiber’s advantages, related to physical-mechanical characteristics and cost, stipulate a new high efficient structural composite materials, which can replace asbestos, metal, timber, plastic materials, etc. The paper investigates the applicability of externally bonded Basalt Fibre Reinforced Polymer (BFRP laminates in strengthening of rectangular reinforced section of a RC beam. The influence of the cross-sectional BFRP area on service and ultimate bending moments and also on service deflection, are analysed. The procedure is based on section analysis, equilibrium of forces and compatibility of strains, considered appropriate for any type of fibres, in case of rectangular RC beams.

  12. Behaviour of fibre-reinforced high-performance concrete in exterior beam-column joint

    Science.gov (United States)

    Muthupriya, P.; Boobalan, S. C.; Vishnuram, B. G.

    2014-09-01

    This paper presents the effect of reinforced high performance concrete (HPC) in exterior beam-column joint with and without fibre under monotonic loading. In this experimental investigation, cross-diagonal bars have been provided at the joint for reducing the congestion of reinforcement in joints, and also M75 grade of concrete with optimum mix proportion of 10 % silica fume and 0.3 % glass fibre was used. Four exterior beam-column joint sub-assemblages were tested. The specimens were divided into two types based on the reinforcement detailing. Type A comprises two joint sub-assemblages with joint detailing as per construction code of practice in India (IS 456-2000), and Type B comprises two joint sub-assemblages with joint detailing as per ductile detailing code of practice in India (IS 13920-1993). In each group there was one specimen of control mix and the remaining one specimen of fibre-reinforced mix. All the test specimens were designed to satisfy the strong column-weak beam concept. The performances of specimens were compared with the control mix and the fibre-reinforced mix. The results show that exterior beam-column joint specimens with silica fume and glass fibre in the HPC mix showed better performance.

  13. Mechanical property analysis of kenaf–glass fibre reinforced polymer composites using finite element analysis

    Indian Academy of Sciences (India)

    M Ramesh; S Nijanthan

    2016-02-01

    Nowadays, natural fibres are used as a reinforcing material in polymer composites, owing to severe environmental concerns. Among many different types of natural resources, kenaf plants have been extensively exploited over the past few years. In this experimental study, partially eco-friendly hybrid composites were fabricated by using kenaf and glass fibres with two different fibre orientations of 0° and 90°. The mechanical properties such as tensile, flexural and impact strengths of these composites have been evaluated. From the experiment, it was observed that the composites with the 0° fibre orientation can withstand the maximum tensile strength of 49.27 MPa, flexural strength of 164.35 MPa, and impact strength of 6 J. Whereas, the composites with the 90° fibre orientation hold the maximum tensile strength of 69.86 MPa, flexural strength of 162.566 MPa and impact strength of 6.66 J. The finite element analysis was carried out to analyse the elastic behaviour of the composites and to predict the mechanical properties by using NX Nastran 9.0 software. The experimental results were compared with the predicted values and a high correlation between the results was observed. The morphology of the fractured surfaces of the composites was analysed using a scanning electron microscopy analysis. The results indicated that the properties were in the increasing trend and comparable with pure synthetic fibre reinforced composites, which shows the potential for hybridization of kenaf fibre with glass fibre.

  14. 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.

  15. Influence of reprocessing on fibre length distribution, tensile strength and impact strength of injection moulded cellulose fibre-reinforced polylactide (PLA composites

    Directory of Open Access Journals (Sweden)

    N. Graupner

    2016-08-01

    Full Text Available The present study focuses on the reprocessing behaviour of recycled injection moulded polylactide (PLA composites. The composites are reinforced with regenerated cellulose fibres (lyocell of variable fineness and a fibre mass content of 30%. They were reprocessed up to three times. The influence of reprocessing on the fibre length distribution and the resulting composite mechanical properties (tensile and impact strength was analysed. While the first reprocessing cycle does not affect the mechanical characteristics of the neat PLA matrix, the strength of the composites decreases significantly due to a decreasing fibre aspect ratio. It was shown that fibres having a larger cross-sectional area display a lower aspect ratio than finer fibres, after reprocessing. This phenomenon leads to a larger decrease in tensile strength of composites reinforced with coarser fibres when compared to composites reinforced with finer fibres. A comparison of virgin composites and threefold reprocessed composites with a similar fibre length distribution resulted in a significantly higher tensile strength compared to the virgin sample. This result leads to the conclusion that not only the fibre length is drastically reduced by reprocessing but also that the fibres and the matrix were damaged.

  16. Toughening and healing of continuous fibre reinforced composites with bis-maleimide based pre-pregs

    Science.gov (United States)

    Kostopoulos, V.; Kotrotsos, A.; Tsantzalis, S.; Tsokanas, P.; Christopoulos, A. C.; Loutas, T.

    2016-08-01

    Unidirectional (UD) pre-pregs containing self-healing materials based on Diels–Alder reaction bis-maleimide (BMI) polymers were successfully incorporated on the mid-plane of UD carbon fibre reinforced polymers. The fracture toughness of these composites and the introduced healing capability were measured under mode I loading. The interlaminar fracture toughness was enhanced considerably, since the maximum load (P max) of the modified composite increased approximately 1.5 times and the mode I fracture energy (G IC) displayed a significant increase of almost 3.5 times when compared to the reference composites. Furthermore the modified composites displayed a healing efficiency (HE) value of about 30% for P max and 20% for G IC after the first healing, appearing to be an almost stable behaviour after the third healing cycle. The HE displayed a decrease of 20% and 15% for P max and G IC values, respectively, after the fifth healing cycle. During the tests, the monitored acoustic emission (AE) activity of the samples showed that there is no significant difference due to the presence of BMI polymer in terms of AE hits. Moreover, optical microscopy not only showed that the epoxy matrix at the interface is partly infiltrated by the BMI polymer, but it also revealed the presence of pulled out fibres at the fractured surface, indicating ductile behaviour.

  17. Laser Surface Pre-treatment of Aluminium for Hybrid Joints with Glass Fibre Reinforced Thermoplastics

    Science.gov (United States)

    Heckert, André; Zaeh, Michael F.

    Lightweight construction is a major trend in the automotive industry. Theconnection of fibre reinforced plastics with aluminium is consequently seen as promising prospect. In this regard, thermal joining can be applied for bonding of such hybrid joints. But in order to create a load bearing metal plastic joint, the surface of the metal has to be pre-treated. Recent research has shown that with laser surface pre-treatment high joint strengths are obtained. Yet there are a variety of laser sources and manufacturable surface topographies with structure sizes ranging from macroscopic to nanoscopic profiles. Within this work,macroscopic, microscopic and nanoscopic laser processed structures are created on aluminium and consequently joined to glass fibre reinforced thermoplastics of different fibre length and fibre content. High shear tensile strengths of up to 42 N/mm2 were obtained depending on the allocated material and the surface pre-treatment.

  18. INFLUENCE OF THERMAL CYCLING ON MICROSTRUCTURE AND THERMAL EXPANSION OF CARBON FIBRES/COPPER COMPOSITES

    Directory of Open Access Journals (Sweden)

    Pavol Štefánik

    2009-06-01

    Full Text Available The preparation of copper matrix reinforced by high modulus carbon fibres (Thornel K1100 as well as the microstructure and dilatation changes during thermocycling is presented.Unidirectional composites with two types of matrix - pure copper and/or copper alloy with 0.2 wt. % of chromium - were thermally cycled between 30-600 °C three times.The composite with pure Cu exhibited larger voids and weak interfacial bonding. Due to the chemical reaction with K1100 fibres a reactive interfacial bonding has been formed. During thermocycling the hysteresis, but no large disintegration was observed. The coefficients of thermal expansion (CTEs strongly depend on fibre orientation. In direction parallel to the fibre orientation in the temperature range of 220-500°C CTEs were very low (0.7-1.0x10-6/K, but in perpendicular direction the CTEs were higher than that of pure copper.

  19. Assessment of the potentialities of recycled steel fibres for the reinforcement of cement based materials

    OpenAIRE

    Barros, Joaquim A. O.; Zamanzadeh, Z.; Mendes, Pedro J. D.; Lourenço, Lúcio

    2013-01-01

    Recent research is evidencing that adding steel fibres recycled from wasted tires can improve the post-cracking behaviour of cement based materials, enhancing the ductility, energy dissipation and impact resistance of elements made by this type of composites. As a consequence, Recycled Steel Fibre Reinforced Concrete (RSFRC) appears as a promising candidate for both structural and non-structural applications. To contribute for the assessment of the potentialities of RSFRC, an e...

  20. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    OpenAIRE

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable resources, are substituted by alternative less energy intensive materials produced from biological renewable resources. The research focuses on the potentials of natural fibres for a successful substituti...

  1. Identification of polymers in waste tyre reinforcing fibre by thermal analysis and pyrolysis

    OpenAIRE

    Acevedo Muñoz, Beatriz; Fernández Fernández, Ana María; Barriocanal Rueda, Carmen

    2014-01-01

    The composition of the reinforcing fibre obtained from the recycling of scrap tyres was analyzed with a view to finding the most suitable applications for it. The material (RF) was separated into two different parts i.e. fibre (F) and microfibre (MF) to ensure the maximum homogeneity of the material under study. Thermogravimetric analysis (TG) together with differential scanning calorimetry (DSC) and infrared spectroscopy (FTIR) were used to identify the polymers present in the waste and to d...

  2. Assessment of thermal shock induced damage in silicon carbide fibre reinforced glass matrix composites

    OpenAIRE

    Boccaccini, A. R.; Boccaccini, D. N.; Pearce, D. H.; Janczak-Rusch, J.

    1998-01-01

    The development of microstructural damage in silicon carbide fibre (Nicalon™) reinforced glass matrix composite samples subjected to thermal shock was investigated by using a nondestructive forced resonance technique and fibre push out indentation tests. Thermal shock testing involved quenching samples in a water bath maintained at room temperature from a high temperature (650ºC). Changes in the Young's modulus and internal friction of the samples with increasing number of shocks were measure...

  3. An Investigation on Flexural Behaviour of Glass Fibre Reinforced Geopolymer Concrete Beams

    OpenAIRE

    Srinivasan, S; Karthik, A.; DR. S. Nagan3

    2014-01-01

    Geopolymer concrete (GPC) are representing the most promising green and eco-friendly alternative to Ordinary Portland Cement (OPC). Geopolymer Concrete possesses relatively good mechanical properties and desirable thermal stability but they exhibit failure behaviour similar to brittle solids. This limitation may be remedied by fibre reinforcement to improve their flexural strength. This paper presents results of an experimental program on the mechanical properties of Fibre Rei...

  4. Development and characterisation of a tungsten-fibre reinforced tungsten composite

    International Nuclear Information System (INIS)

    In tungsten-fibre reinforced tungsten, tungsten wire is combined with a tungsten matrix. The outstanding ductility of the fibres and extrinsic mechanisms of energy dissipation lead to an intense toughening. With extensive analytical and experimental investigations a manufacturing method based on chemical vapour infiltration is developed and first material is produced. The toughening mechanisms are shown by means of sophisticated mechanical experiments i.a. X-ray microtomography.

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

    International Nuclear Information System (INIS)

    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

  6. 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...

  7. Comparative Environmental Sustainability Assessment of Bio-Based Fibre Reinforcement Materials for Wind Turbine Blades

    DEFF Research Database (Denmark)

    Corona, Andrea; Markussen, Christen Malte; Birkved, Morten;

    2015-01-01

    turbines have therefore partially been focused on substitution of conventional fibre materials with bio-fibres assuming that this substitution was in the better for the environment and human health. The major question is if this material substitution, taking into account a multitude of environmental impact...... categories, not only climate change, actually is supporting sustainable development or if the development of sustainable composite materials is more complex and perhaps even contra-intuitive due to complex trade-offs. Based on a case study 4 different types of fibres and fibre mixtures (flax, carbon, glass...... and flax/carbon, flax/glass mixed fibres) are compared in terms of environmental sustainability. Applying one of the most recent life cycle impact assessment methods, we demonstrate that the environmental sustainability of natural fibre based composite materials is similar or even lower, within...

  8. 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.

  9. Defect localization in fibre-reinforced composites by computing external volume forces from surface sensor measurements

    International Nuclear Information System (INIS)

    We suggest a prospective method for detecting and visualizing defects in fibre-reinforced composites by computing external volume forces from measurements acquired by sensors that are integrated on the surface of the structure. Anisotropic materials like carbon fibre-reinforced composites are widely used in light weight construction which can exhibit damages that are not optically detectable. The key idea of our method is the interpretation of defects in such structures as if they were induced by an external volume force. This idea is based on the observation that a propagating elastic wave interferes with a damaged area by reflecting the wave. In that sense a damage can be seen as an additional source. Thus identifying the external volume force which has caused this wave is supposed to reveal the location of the defect. This approach leads to the inverse problem of determining the inhomogeneity of a hyperbolic initial-boundary value problem. We tackle this ill-posed problem by minimizing a Tikhonov functional which takes the oberservation points of our surface measurements into account. In the article we address the solvability of the direct problem, state and analyze the PDE-based optimization problem that aims for computing the external force and develop a numerical realization of its solution using the conjugate gradient method. First numerical results for a simple model case with different sensor adjustments show that the defects in fact are detectable. In that sense this article might be seen as starting point of future research which should comprehend deeper numerical studies and analysis of the problem. (paper)

  10. 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.

  11. Regenerated thermosetting styrene-co-acrylonitrile sandwich composite panels reinforced by jute fibre: structures and properties

    Indian Academy of Sciences (India)

    Jinglong Li; Qin Peng; Anrong Zeng; Junlin Li; Xiaole Wu; Xiaofei Liu

    2016-02-01

    Jute fibres-reinforced sandwich regenerated composite panels were fabricated using industrial waste thermosetting styrene-co-acrylonitrile (SAN) foam scraps via compression moulding for the purpose of recycling waste SAN foam and obtaining high physical performance. The jute fibres were, respectively, treated by heat, sodium hydroxide (NaOH) solution (5.0 wt%), and N,N-dimethylacetamide (DMAc) in order to improve the mechanical properties of the composites. The structures and mechanical properties of the composites were studied. The SAN matrix got compact and some crystalline region formed in SAN matrix via compression moulding. The composite reinforced by DMAc-treated jute fibres performed optimum mechanical properties among the regenerated panels whose impact strength, flexural strength, and compressive strength were 19.9 kJ m−2, 41.7 MPa, and 61.0 MPa, respectively. Good interfacial bonding between DMAc-treated fibres and SAN matrix was verified by peel test and exhibited in SEM photographs. Besides, the water absorption of DMAc-treated fibres composite was lower than other SAN/jute fibre-reinforced sandwich composite panels.

  12. 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

    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)...

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

    International Nuclear Information System (INIS)

    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

  14. Numerical modelling of elastic behaviour of concrete reinforced with steel short fibres in plane stress conditions

    Directory of Open Access Journals (Sweden)

    Fabian Lamus

    2011-01-01

    Full Text Available This work describes a numerical model of fibre reinforced concrete elastic behaviour implemented using the finite elements method (Hughes, 2000. In structures made of this material, each point is formed by steel fibres embedded into a simple concrete matrix. The reinforced concrete is represented inside a finite element as an orthotropic material having random material direction based on the vanishing diameter fibre model (Dvorak and Bahei-el-Din, 1982 and the mixing theory modified for short length reinforcement (Oller, 2003. Statistical analysis consisted of repeating the problem’s numerical simulation where the direction of fibres was modified by a random function to set up a sampling database from the results and measure their variability. A sensitivity study of finite element size and the number of sampling data was then carried out in terms of total strain energy. Finite element size and sampling data are recommended. The average structural response of a reinforced concrete beam with different quantities of steel fibres where minimum data dispersion was observed is given as an example of applying the above.

  15. Behaviour of alkaline cement mortars reinforced with acrylic and polypropylene fibres

    OpenAIRE

    Puertas, P.; Amat, T.; Vázquez, T.

    2000-01-01

    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 f...

  16. 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.

  17. 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.

  18. Morphology and mechanical behaviour of concretes reinforced by amorphous cast fibres

    International Nuclear Information System (INIS)

    This research thesis addresses the characterization of the morphology and mechanical behaviour of concretes reinforced by amorphous cast fibres. It first gathers some general characteristics and observations related to the amorphous cast fibre: roughness, failure mode, amorphous structure, X-ray analysis, fire resistance. Experimental methods and techniques developed for morphological analysis and mechanical tests are presented (sample preparation, tensile test, and compression sample) and the use of image automatic analysis techniques is then addressed (void morphology and granulometry analysis, inter-void distance measurement, fibre spatial distribution). The next part reports the study of the mechanical behaviour under axial compression

  19. 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.

  20. Predicting the tensile modulus and strength of single and hybrid natural fibre reinforced thermoplastic composites

    Science.gov (United States)

    Facca, Angelo George

    Natural fibre reinforced thermoplastics (NFRT) are used in a variety of commercial applications, but there is little theoretical modeling of structure/property relationships in these materials. In this thesis, micromechanical models available in the short-fibre literature were adapted to predict the tensile modulus and strength of some NFRT formulations. Hemp, 20 and 40-mesh hardwood, rice hulls and E-glass fibres were blended into HDPE to produce single and hybrid composites. Changes in fibre density and moisture content that occur during composite manufacturing were included in the micromechanical models. To account for fibre densification, the Young's modulus of the natural fibres was determined on a cell wall basis. A modified hybrid rule of mixtures (HROM) equation that uses experimental data from single NFRT was developed and found to adequately predict the tensile modulus of the hybrid composites. The tensile modulus for both the single and hybrid composites was found to linearly increase with an increase in fibre loading. The failure mechanism for all composite specimens was due to fibre pullout followed by matrix failure. Consequently the tensile strength of the NFRT was predicted using a ROM strength equation, which was modified with a derived semi-empirical fibre clustering parameter. The clustering parameter correctly predicted that as fibre loading increased, the average fibre stress would decrease. By assuming no contact between different types of fibres it was possible to use a modified HROM strength equation to predict the tensile strength of the hybrid composites. As a result parameters taken from the respective single fibre systems could be applied directly to the HROM equation. The modified ROM and HROM strength equations adequately predicted the tensile strength of various single and hybrid fibre reinforced composites over a wide range of composite loading. In this study experiments were conducted to shed light on the effect of a coupling agent

  1. Reinforcing Efficiency of Crimped Profile of Polypropylene Fibres on the Cementitious Matrix

    Directory of Open Access Journals (Sweden)

    S. Thirumurugan

    2013-08-01

    Full Text Available Fibre reinforcement in concrete is an effective solution for improving tensile properties of concrete. Different types of fibres such as steel, polypropylene, glass and polyester were commonly used in concrete. In the present study, the effect of adding crimped polypropylene fibres on the improvement in the compressive properties of hardened concrete was studied. Crimped polypropylene fibres with different levels of reinforcements index was investigated systematically with designed concrete mixtures consisting of various fibres dosages of 0.1 to 0.5% by volume of concrete. The effect of crimped profile of polypropylene fibres on the improvement in failure properties of concrete in compression and flexural tension were evaluated. Test results showed that polypropylene fibres showed higher fracture energy absorption and exhibited a marginal improvement in strength index and sudden failure is prevented resulting in multiple splitting cracks. The ultrasonic pulse velocity test results were also found to be consistent and exhibited a good integrity for all CPFRC concrete specimens. A maximum compressive strength was noted at an optimum dosage of 3.0% of CPFRC specimens with a strength value of 24.67 and 34.92 MPa at 7 and 28 days respectively.

  2. Recycling of Glass Fibre Reinforced Aluminium Laminates and Silicon Removal from Aerospace Al Alloy

    OpenAIRE

    Zhu, G

    2012-01-01

    Aerospace aluminium alloys (7xxx and 2xxx series Al alloy) is one of the important Al alloys in our life. The recycling of aerospace Al alloy plays a significant role in sustainable development of Al industry. The fibre reinforced metal laminates GLARE including 67 wt.% 2024 Al alloy was used as upper fuselage in Airbus A380, but the solution for GLARE recycling is not available. Thermal recycling which uses high temperature to decompose the resin and separate the reinforcement fibres and fil...

  3. Improvement of ternary recycled polymer blend reinforced with date palm fibre

    International Nuclear Information System (INIS)

    Highlights: • Date palm fibre treated with 1% MA improved adhesion and dispersion in the blend. • The improvement in mechanical properties and thermal stability were confirmed. • Fibre addition did not change melting and crystallisation temperature of the blends. - Abstract: This paper investigates the study and preparation of date palm fibre reinforced recycled polymer blend composites. This is the first paper which describes the recycled polymer ternary blends of (1) recycled low density polyethylene (RLDPE), (2) recycled high density polyethylene (RHDPE) and (3) recycled polypropylene (RPP). The date palm fibre reinforced composites (CD00) were prepared by maintaining constant weight% of fibre of 20 wt% without any fibre treatment. Maleic anhydride (MA) was used as the compatabilizer (1 and 2 wt%) and the effect of compatabilizer on the blend matrix composites was studied. The mechanical, thermal, morphological properties, water absorption and chemical resistance properties were evaluated for these composites and also studied for pure blend matrix (C00). Date palm fibre improved the tensile strength and hardness of recycled polymer blend matrix. Further improvement was achieved with 1% MA (CD1), which showed that 1% MA treated composites (CD1) had higher tensile strength, modulus and hardness properties. Thermal stability and water absorption were improved by 1% MA. These improvements were demonstrated at the nanoscale level by the decrease in roughness appearing in Atomic Force Spectroscopic Microscopy analysis indicating that flow is better under this concentration. The SEM analysis also showed that the fibre matrix adhesion improved by adding 1 wt% (CD1) of MA. The melting and crystallisation temperatures of the blends did not change with the addition of date palm fibre and MA, indicating that the additives did not influence the melting and crystallisation properties of the composites. The chemical resistance test results showed that these composites

  4. Electrochemical characteristics of a carbon fibre composite and the associated galvanic effects with aluminium alloys

    International Nuclear Information System (INIS)

    Highlights: • Exposed carbon fibres on two defined regions (“front” and “side”) are a focus of the investigation in NaCl electrolyte. • The exposed carbon fibres on the side and front regions are responsible for a high cathodic current density. • The NaCl + CuSO4 electrolyte was used to investigate the cathodic polarization behaviour of the exposed carbon fibres. • Galvanic coupling behaviour between the composite and aluminium alloys (AA7075-T6 and AA1050) was measured in NaCl electrolyte. • The higher galvanic current density measured on AA1050 alloy introduced a higher dissolution rate than the AA7075-T6 alloy. - Abstract: The electrochemical behaviour of a carbon fibre reinforced epoxy matrix composite in 3.5% NaCl and 3.5% NaCl + 0.5 M CuSO4 electrolytes was examined by potentiodynamic polarisation, potentiostatic polarisation and scanning electron microscopy. Exposed carbon fibres on two defined regions (“front” and “side”) are a focus of the investigation. The large size of the exposed carbon fibres on the side region is responsible for a higher cathodic current density than the front region in the NaCl electrolyte. The deposition of copper on the front surface of composite confirmed that the significantly higher cathodic current resulted from the exposure of the fibres to the NaCl electrolyte. Galvanic coupling between the composite and individual aluminium alloys (AA7075-T6 and AA1050) was used to measure galvanic potentials and galvanic current densities. The highly alloyed AA7075-T6 alloy and its high population density of cathodic sites compared to the AA1050 acted to reduce the galvanic effect when coupled to the composite front or side regions

  5. Low temperature electrical transport in modified carbon nanotube fibres

    International Nuclear Information System (INIS)

    Carbon nanotube fibres are a new class of materials highly promising for many electrical/electronic applications. The range of applications could be extended through the modification of their electrical transport properties by inclusions of foreign materials. However, the changes in electrical transport are often difficult to assess. Here, we propose that the analysis of resistance–temperature dependencies of modified fibres supported by a recently developed theoretical model may aid research in this area and accelerate real life applications of the fibres

  6. Preparation Of Melt Spun Electroconductive Fine Fibres Containing Carbon Nanotubes

    OpenAIRE

    Mirjalili Mohammad; Karimi Loghman

    2015-01-01

    Preparation of electroconductive fine fibres containing carbon nanotubes (CNTs) by melt spinning was the main goal of the present study. In this regard, the influence of the main operating parameters such as type of polymer used (polyester, polypropylene and polyamide), type and concentration of the CNTs on conductivity, and mechanical and thermal properties of the melt spun fibres was studied. The conductivity of melt spun fibres was measured based on the method developed by Morton and Hearl...

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

    Science.gov (United States)

    Pereira, G F; Mikkelsen, L P; McGugan, M

    2015-01-01

    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. PMID:26513653

  8. Rehabilitation and strengthening of concrete structures using Ultra-High Performance Fibre Reinforced Concrete

    OpenAIRE

    Brühwiler, Eugen

    2012-01-01

    An original concept is presented for the durable rehabilitation and strengthening of concrete structures. The main idea is to use Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) complemented with steel reinforcing bars to “harden” and strengthen those zones of the structure that are exposed to severe environmental influences and high mechanical loading. This concept combines efficiently protection and resistance properties of UHPFRC and significantly improves the structural performa...

  9. Rehabilitation and Strengthening of Concrete Structures Using Ultra-High Performance Fibre Reinforced Concrete

    OpenAIRE

    Bruehwiler, Eugen; Denarie, Emmanuel

    2013-01-01

    An original concept is presented for the durable rehabilitation and strengthening of concrete structures. The main idea is to use ultra-high performance fibre reinforced concrete (UHPFRC) complemented with steel reinforcing bars to protect and strengthen those zones of the structure that are exposed to severe environmental influences and high mechanical loading. This concept efficiently combines the protection and resistance properties of UHPFRC and significantly improves the structural perfo...

  10. Comparison of Performance of Standard Concrete And Fibre Reinforced Standard Concrete Exposed To Elevated Temperatures

    OpenAIRE

    K. Srinivasa Rao

    2013-01-01

    Concrete elements exposed to fire undergo temperature gradients and as a result, undergo physical changes or spalling which leads to expose steel reinforcement. This causes distress in concrete structures. The performance of concrete can be improved with the addition of steel fibres to concrete especially when it is exposed to heat. Therefore, this study has been carried out to generate experimental data on standard concrete ofgrade M45 and Fiber Reinforced Standard Concrete exposed to elevat...

  11. On the tensile properties and fracture behaviour of steel fibre reinforced self-compacting concrete laminar structures

    OpenAIRE

    Abrishambaf, Amin; Cunha, Vitor M. C. F.; Barros, Joaquim A. O.

    2014-01-01

    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) sp...

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. 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.

  16. A Review of the Radio Frequency Non-destructive Testing for Carbon-fibre Composites

    OpenAIRE

    Li Zhen; Meng Zhaozong

    2016-01-01

    The purpose of this paper is to review recent research on the applications of existing non-destructive testing (NDT) techniques, especially radio frequency (RF) NDT, for carbon-fibre reinforced plastics (CFRP) composites. Electromagnetic properties of CFRP composites that are associated with RF NDT are discussed first. The anisotropic characteristic of the conductivity and the relationship between the penetration depth and conductivity should be paid much attention. Then, the well-established...

  17. Percolation Effects In Electrical Conductivity Of Carbon Fibre Composites

    OpenAIRE

    Chippendale, Richard; Golosnoy, Igor O

    2011-01-01

    The effects due to percolation on the bulk electrical conductivity of Carbon Fibre Composites are studied in detail. To simulate the CFCs manufacturing process the fibres are placed randomly in the polymer matrix using Monte Carlo based simulation techniques. The electric conductivity of the CFCs was then analysed using finite element modelling.

  18. Recycling of Glass Fibre Reinforced Aluminium Laminates and Silicon Removal from Aerospace Al Alloy

    NARCIS (Netherlands)

    Zhu, G.

    2012-01-01

    Aerospace aluminium alloys (7xxx and 2xxx series Al alloy) is one of the important Al alloys in our life. The recycling of aerospace Al alloy plays a significant role in sustainable development of Al industry. The fibre reinforced metal laminates GLARE including 67 wt.% 2024 Al alloy was used as upp

  19. Investigations on the bending tensile strength of thermally highly stressed concrete reinforced with steel fibres

    International Nuclear Information System (INIS)

    The aim of the research project was to study the bending tensile strength behaviour of concrete reinforced with steel fibres under extreme thermal loads. The high temperature range up to temperatures of 800deg C was particularly researched experimentally. (orig./MM)

  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...

  1. Mechanical behaviour of chicken quills and chicken feather fibres reinforced polymeric composites

    Directory of Open Access Journals (Sweden)

    M. Uzun

    2011-12-01

    Full Text Available Purpose: The objective of this study is to utilise and evaluate the mechanical properties of the chicken feather quill and fibre reinforced vinylester and polyester composites.Design/methodology/approach: Prior to production of the composites, the chicken feather fibres (CFF were cleaned, tested and analyzed in terms of physical properties; linear density and tensile behaviour. The unidirectional CFF reinforced composites were produced with vinylester and polyester resins with three fibre reinforcement loadings (2.5, 6, 10wt%. Following experiments were conducted to determine physical properties of the control (0% and CFF reinforced composites; tensile, flexural and Charpy impact testing.Findings: It was found that the impact properties of the CFF reinforced composites are significantly better than the control composites however both the tensile and the flexural properties of the CFF reinforced composites have poorer values compared to the control composites. For the 10% CFF reinforced vinylester composite, Charpy impact value was 4.42 kgj/mm2 which was 25% higher than the control vinylester composites (3.31 kgj/mm2 and also for the 10% CFF reinforced polyester (4.56 kgj/mm2 composite had three times better impact resistance than the control composite (1.85 kgj/mm2.Practical implications: The CFF reinforced composite have potential applications due to its improved impact behaviour.Originality/value: If the poultry waste can be utilised and used any engineering applications they will be preferred due to low-cost and superior characteristics and the most importantly they will not cause ecological and health problems.

  2. Preparation Of Melt Spun Electroconductive Fine Fibres Containing Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Mirjalili Mohammad

    2015-06-01

    Full Text Available Preparation of electroconductive fine fibres containing carbon nanotubes (CNTs by melt spinning was the main goal of the present study. In this regard, the influence of the main operating parameters such as type of polymer used (polyester, polypropylene and polyamide, type and concentration of the CNTs on conductivity, and mechanical and thermal properties of the melt spun fibres was studied. The conductivity of melt spun fibres was measured based on the method developed by Morton and Hearl. The morphologies of the CNTs–polymer composite fibres were studied by scanning electron microscopy. Thermal behaviours and mechanical properties of the CNTs–polymer composite fibres were investigated using differential scanning calorimetry and tearing tester, respectively. The results reveal that using CNTs had tangible effect on electrical, thermal and mechanical properties of the melt spun fibres. Also, polyamide had a better dispersion of CNTs and correspondingly lower surface resistivity.

  3. Assessment of solvent capsule-based healing for woven E-glass fibre-reinforced polymers

    Science.gov (United States)

    Manfredi, Erica; Cohades, Amaël; Richard, Inès; Michaud, Véronique

    2015-01-01

    Vacuum Assisted Resin Infusion Molding (VARIM) with low vacuum pressure difference was used to manufacture woven glass fibre-reinforced epoxy resin plates, with a fibre volume fraction of approx. 50 vol% and containing ethyl phenylacetate (EPA)-filled capsules for self-healing purposes. Capsules were introduced by functionalising the fabrics through manual dispersion. We investigated the capability of autonomously healing delaminations induced by static loading in Mode I and II. Healing did not take place for composite samples; this was attributed to the presence of bare fibres on the crack plane and to the reduction of EPA diffusion into the matrix in the presence of fibres both of which hinder the swelling mechanism responsible for healing the cracks.

  4. Assessment of solvent capsule-based healing for woven E-glass fibre-reinforced polymers

    International Nuclear Information System (INIS)

    Vacuum Assisted Resin Infusion Molding (VARIM) with low vacuum pressure difference was used to manufacture woven glass fibre-reinforced epoxy resin plates, with a fibre volume fraction of approx. 50 vol% and containing ethyl phenylacetate (EPA)-filled capsules for self-healing purposes. Capsules were introduced by functionalising the fabrics through manual dispersion. We investigated the capability of autonomously healing delaminations induced by static loading in Mode I and II. Healing did not take place for composite samples; this was attributed to the presence of bare fibres on the crack plane and to the reduction of EPA diffusion into the matrix in the presence of fibres both of which hinder the swelling mechanism responsible for healing the cracks. (paper)

  5. The Compatibility Effect Of Coupling Agent On Rheological-Morphological Relationship Of Banana Fibre Reinforced Polypropylene

    International Nuclear Information System (INIS)

    The rheological properties of banana fibre reinforced polypropylene (PP/BF) composites at different composition were analysed using Shimadzu capillary rheometer. The effect of coupling agent concentration on the rheological properties was studied and followed by drawing a relationship of rheological-morphological properties of PP/BF composites. It was found that all composite system exhibits pseudoplasticity and incorporation of treated fibres consequents enhanced viscosity due to improved interfacial adhesion at fibre-matrix interface. However, it was observed that PP/BF composite with 2 wt% silane concentration does not yield further enhancement in the rheological properties when compared to that of 1 wt%. Composites with 1 wt% silane concentration were found to yield most promising compatibility effect with well-oriented and uniformly dispersed fibre morphology.

  6. In-plane shear test of fibre reinforced concrete panels

    DEFF Research Database (Denmark)

    Solgaard, Anders Ole Stubbe; Stang, Henrik; Goltermann, Per

    2008-01-01

    The present paper concerns the investigation of polymer Fiber Reinforced Concrete (FRC) panels subjected to in-plane shear. The use of fibers as primary reinforcement in panels is a new application of fiber reinforcement, hence test methods, design bases and models are lacking. This paper...... determined from wedge splitting test (WST) specimens and compression cylinders. Three different test series were cast, where the only parameter which was varied was the amount of fibers in the mix, viz. 0.5, 1.0 and 1.5 vol. % fibers, respectively. Three identical experiments with panels were carried out in...

  7. Hierarchical analysis of the degradation of fibre-reinforced polymers under the presence of void imperfections.

    Science.gov (United States)

    Liebig, Wilfried V; Schulte, Karl; Fiedler, Bodo

    2016-07-13

    The subject of this work is the investigation of the influence of voids on the mechanical properties of fibre-reinforced polymers (FRPs) under compression loading. To specify the damage accumulation of FRPs in the presence of voids, the complex three-dimensional structure of the composite including voids was analysed and a reduced mechanical model composite was derived. The hierarchical analysis of the model composite on a micro-scale level implies the description of the stress and strain behaviour of the matrix using the photoelasticity technique and digital image correlation technology. These studies are presented along with an analytical examination of the stability of a single fibre. As a result of the experimental and analytical studies, the stiffness of the matrix and fibre as well as their bonding, the initial fibre orientation and the fibre diameter have the highest impact on the failure initiation. All these facts lead to a premature fibre-matrix debonding with ongoing loss of stability of the fibre and followed by kink-band formation. Additional studies on the meso-scale of transparent glass FRPs including a unique void showed that the experiments carried out on the model composites could be transferred to real composites.This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. PMID:27242296

  8. Aluminum/glass fibre and aluminum/carbon fibre hybrid laminates

    Directory of Open Access Journals (Sweden)

    Ana STAN

    2010-06-01

    Full Text Available The metal/fibre hybrid laminates consist of an alternation of 0.2 ÷ 0.5 mm metallic sheets(Aluminum or Titanium in Aeronautical Engineering and pre-pregs made of unidirectional carbon oraramid or glass fibre or of the two-dimensional fabric of these materials, bonded by a polymeradhesive (epoxy, especially. Compared with the monolithic metal foils, the essential quality of thesehybrid laminates is their superior resistance to fatigue, impact and crack propagation (existing ormade by notches. The paper presents some results regarding hybrid laminates aluminium-carbonfibre and aluminum-glass fibre achieved in the CEEX project X1C05 (2005.

  9. 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.

  10. Finite element analysis of stress transfer in carbon nanotube reinforced magnesium matrix composites

    OpenAIRE

    Li, Sinian; Wang, Yang; Rümmeli, M. H.; Vlček, Jaroslav; Pištora, Jaromír; Lesňák, Michal

    2010-01-01

    A simplified finite element model was established to simulate deformation of carbon nanotubes (CNTs) reinforcing magnesium matrix composites during the tensile test. The stress and strain of matrix and reinforcement agent and the effect of interface on mechanical behaviour of composites were specially studied. The simulation results showed that for uniformly distributed CNTs a stress concentration occurs from the fibre axis towards the interface. The simulations proved that the destruction of...

  11. An Overview of Okra Fibre Reinforced Polymer Composites

    Science.gov (United States)

    Srinivasababu, Nadendla

    2015-05-01

    Increasing attention towards “sustainable environment” invited the development of new materials to satisfy the needs of the public with less/no damage on surroundings. In this regard a specific attempt is made by the author to do review and understand the performance of the variable vegetable fibres of okra which is botanically called ‘Abelmoschus Esculentus’ and their composites under various conditions of load. Further the results exist in the literature are also reviewed for the purpose of comparison.

  12. STRAIN HARDENING PROPERTIES OF STEEL FIBRE REINFORCED LATEX CONCRETE COMPOSITE

    OpenAIRE

    V.M. Sounthararajan; Deependra Singh; Shreyansh Parakh; S. Thirumurugan; A. Sivakumar

    2013-01-01

    Steel fibre addition in concrete possesses high merits in terms of achieving homogeneity and tensile strength properties. Polymeric addition in concrete has high advantages in terms of pore fillingeffect and subsequent increase in durability index. The combined addition of steel and polymeric latex additions in concrete leads to increased strength, durability, toughness, resistance to cracking and crack propagation. Studies were conducted in the present study to analyse the properties of conc...

  13. Hygrothermal degradation and fracture process of advanced fibre-reinforced plastics

    Energy Technology Data Exchange (ETDEWEB)

    Komai, K.; Minoshima, K.; Shiroshita, S. (Dept. of Mechanical Engineering, Kyoto Univ. (Japan))

    1991-09-15

    An investigation has been carried out on the effects of water absorption on the mechanical properties and fatigue strength of unidirectionally reinforced carbon-epoxy (CFRP) and aramid-epoxy (AFRP). T-1/347 normal-type CFRP absorbed more water than MM-1/982X heat-resistant-type CFRP. After a long immersion of about 7 months, however, MM-1/982X composites absorbed water rapidly and the fatigue strength was considerably decreased. In T-1/347 wet specimens preconditioned in water for 2 months a high amount of water absorption degraded the matrix and decreased the strength of the fibre-matrix interface, thereby worsening the mechanical properties. For MM-1/982X composites a small amount of water absorption moderately decreased the interfacial strength and increased the ductility of the matrix, thereby improving the mechanical properties. However, the fatigue lives of wet specimens of both CFRPs were decreased in water. Water absorption lowered the yield strength of the epoxy resin, thereby changing the shape of the stress-strain curves of AFRP. This had no effect on the tensile strength of the composites. Water absorption increased the fatigue strength of both Dupont's Kevlar-49 and Teijin's Technora AFRP. The water absorption increased the ductility of the matrix and enabled local realignment of the fibres. The Technora composite had a stronger interface than the Kevlar-49 composite. Water absorption lowered the interfacial strength of both AFRPs and changed the failure mechanisms. In these tests the synthesized evaluation of acoustic emission (AE) signals using several AE parameters was carried out and the fracture mechanisms were discussed in terms of the observations of internal damage by a scanning acoustic microscope and of fracture surfaces by a scanning electron microscope.

  14. Analysis of a Carbon Fibre Rim : Student Formula

    OpenAIRE

    Uyttersprot, Bryan

    2015-01-01

    This master’s thesis is within the context of a formula race competition between universities. The main goal is to replace the modern rims of the TAMK Student Formula car by lighter and more efficient rims. To achieve this goal, important topics such as general rim design, tyre forces, tyre moments, strength of materials, fatigue and mechanical properties of carbon fibre were examined. Carbon fibre was applied because of its decent strength, weight and fatigue characteristics. Two possib...

  15. Raman Spectroscopic Studies of Carbon Nanotube Composite Fibres

    OpenAIRE

    Deng, Libo

    2011-01-01

    The project has been concerned with structure/property relationships in a series of different carbon nanotube (CNT) composite fibres. Raman spectroscopy has been proved to be a powerful technique to characterise the CNT-containing fibres. Electrospinning has been used to prepare poly(vinyl alcohol) (PVA) nanofibres containing single-wall carbon nanotubes (SWNTs). The effect of the processing conditions including the polymer concentration, electric voltage, tip-to-collector distance, nanotube ...

  16. 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;

    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...... 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....

  17. 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 materia...... the fibres. This strain for yield is lower than the strain for the unhindered relaxation in the dispersion-hardened material Cu-SiO2.......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...... predicts numerical values of the correct order of magnitude. The cyclic hardening rates were large compared to. e.g. pure Cu. and they were constant within the experimental limits. At larger strains, about 0.5% at 77 K and 0.4% at room temperature, irreversible relaxation of Cu-W was initiated by yield of...

  18. Elastomer Reinforced with Carbon Nanotubes

    Science.gov (United States)

    Hudson, Jared L.; Krishnamoorti, Ramanan

    2009-01-01

    Elastomers are reinforced with functionalized, single-walled carbon nanotubes (SWNTs) giving them high-breaking strain levels and low densities. Cross-linked elastomers are prepared using amine-terminated, poly(dimethylsiloxane) (PDMS), with an average molecular weight of 5,000 daltons, and a functionalized SWNT. Cross-link densities, estimated on the basis of swelling data in toluene (a dispersing solvent) indicated that the polymer underwent cross-linking at the ends of the chains. This thermally initiated cross-linking was found to occur only in the presence of the aryl alcohol functionalized SWNTs. The cross-link could have been via a hydrogen-bonding mechanism between the amine and the free hydroxyl group, or via attack of the amine on the ester linage to form an amide. Tensile properties examined at room temperature indicate a three-fold increase in the tensile modulus of the elastomer, with rupture and failure of the elastomer occurring at a strain of 6.5.

  19. Wear behaviour of composite materials based on 2024 Al-alloy reinforced with δ alumina fibres

    Directory of Open Access Journals (Sweden)

    J.W. Kaczmar

    2010-11-01

    Full Text Available Purpose: Wear improvement of aluminum matrix composite materials reinforced with alumina fibres, was investigated. The effects of the applied pressure and T6 heat treatment on wear resistance were determined.Design/methodology/approach: Wear tests were carried out on pin-on disc device at constant sliding velocity and under three pressures, which in relation to diameter of specimens corresponds to pressures of 0.8 MPa, 1.2 MPa and 1.5 MPa. To produce composite materials porous performs were prepared. They are characterized by the suitable permeability and good strength required to resist stresses arising during squeeze casting process. Performs exhibited semi-oriented arrangement of fibres and open porosity enabled producing of composite materials 10% (in vol.% of Al2O3 fibres (Saffil.Findings: In comparison with T6 heat treated monolithic 2024 aluminium alloy composites revealed slightly better resistance under lower pressure. Probably, during wear process produced hard debris containing fragments of alumina fibres are transferred between surfaces and strongly abrade specimens. Under smaller pressures wear process proceeded slowly and mechanically mixed layer MML was formed.Research limitations/implications: Reinforcing of 2024 aluminium alloy could be inefficient for wear purposes. Remelting and casting of wrought alloy could deteriorate its properties. Interdendrite porosities and coarsening of grains even after squeeze casting process were observed.Practical implications: Aluminum casting alloys can be locally reinforced to improve hardness and wear resistance under small pressures.Originality/value: Investigations are valuable for persons, what are interested in aluminum cast composite materials reinforced with ceramic fibre performs.

  20. Effect of fibre content and alkali treatment on mechanical properties of Roystonea regia-reinforced epoxy partially biodegradable composites

    Indian Academy of Sciences (India)

    Govardhan Goud; R N Rao

    2011-12-01

    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. The reinforcement Roystonea regia (royal palm) fibre was collected from the foliage of locally available royal palm tree through the process of water retting and mechanical extraction. The poor adhesion between fibre and matrix is commonly encountered problem in natural-fibre-reinforced composites. To overcome this problem, specific physical and chemical treatments were suggested for surface modification of fibres by investigators. Alkali treatment is one of the simple and effective surface modification techniques which is widely used in natural fibre composites. In the present study both untreated and alkali-treated fibres were used as reinforcement in Roystonea regia epoxy composites and the tensile, flexural and impact properties were determined at different fibre contents. The alkali treatment found to be effective in improving the tensile and flexural properties while the impact strength decreased.

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

    International Nuclear Information System (INIS)

    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.

  2. Dynamic damage in carbon-fibre composites.

    Science.gov (United States)

    Bourne, N K; Parry, S; Townsend, D; Withers, P J; Soutis, C; Frias, C

    2016-07-13

    The Taylor test is used to determine damage evolution in carbon-fibre composites across a range of strain rates. The hierarchy of damage across the scales is key in determining the suite of operating mechanisms and high-speed diagnostics are used to determine states during dynamic loading. Experiments record the test response as a function of the orientation of the cylinder cut from the engineered multi-ply composite with high-speed photography and post-mortem target examination. The ensuing damage occurs during the shock compression phase but three other tensile loading modes operate during the test and these are explored. Experiment has shown that ply orientations respond to two components of release; longitudinal and radial as well as the hoop stresses generated in inelastic flow at the impact surface. The test is a discriminant not only of damage thresholds but of local failure modes and their kinetics. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. PMID:27242311

  3. Preparation of PCL/glass fibre and PCL/carbon fibre composites by γ rays irradiation and their biodegradability

    International Nuclear Information System (INIS)

    A new biodegradable polymer coating fibre cloth composites has been achieved by γ rays irradiation. The mechanical properties (Bending Strength and bending Modulus) of poly (ε-caprolactone), PCL/carbon or glass fibre composites were investigated. γ rays irradiation improved the mechanical properties of composites due to the formation of gel by crosslinking. PCL/glass fibre cloth reinforced composites by irradiation at supercooled state in vacuum with increasing dose up to 270 kGy, the composites gave higher bending strength of 1.5 times and bending modulus of 1.35 times compared with unirradiated composites. PCL in composites degraded by microorganisms in soil burial test and enzymatic degradation test. The degradation led to a weight loss. During enzymatic degradation test, after 23 h immersion there were a 100% PCL weight loss for the unirradiated composite and 54% PCL weight loss for the irradiated composite. Weight loss of PCL gradually increases with increasing burial time. After 12 weeks in burial time, weight loss of 30% PCL was achieved for the uncrosslinked composite, while, for crosslinked composite (gel content 69%), weight loss of 20% was achieved

  4. Single Fibre Pullout from Hybrid Fiber Reinforced Concrete

    NARCIS (Netherlands)

    Markovich, I.; Van Mier, J.G.M.; Walraven, J.C.

    2001-01-01

    Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes inter

  5. Mechanical performance of oil palm empty fruit bunches/jute fibres reinforced epoxy hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    Jawaid, M. [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abdul Khalil, H.P.S., E-mail: akhalilhps@gmail.com [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abu Bakar, A. [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2010-11-15

    Research highlights: {yields} Hybrid composites constituents of natural fibres show good mechanical performances. {yields} Hybridization with 20% jute fibre gives rise to sufficient modulus to composites. {yields} Outer or core material affect mechanical performance of hybrid composites. {yields} Impact strength of pure EFB composite is higher than hybrid composites. - Abstract: Oil palm empty fruit bunches (EFB)/jute fibre reinforced epoxy hybrid composites with different sequence of fibre mat arrangement such as EFB/jute/EFB and jute/EFB/jute were fabricated by hand lay-up method. The effect of layering patterns on the mechanical performance of the composites was studied. The hybrid composites are intended for engineering applications as an alternative to synthetic fibre composites. Mechanical performance of hybrid composites were evaluated and compared with the pure EFB, pure jute composites and neat epoxy using flexural and impact testing. The flexural properties of hybrid composite is higher than that of pure EFB composite with respect to the weight fraction of fibre, where as the impact strength of pure EFB composite is much higher than those of hybrid composites. The flexural results were interpreted using sandwich theory. The fracture surface morphology of the impact testing samples of the hybrid composites was performed by scanning electron microscopy (SEM).

  6. Mechanical performance of oil palm empty fruit bunches/jute fibres reinforced epoxy hybrid composites

    International Nuclear Information System (INIS)

    Research highlights: → Hybrid composites constituents of natural fibres show good mechanical performances. → Hybridization with 20% jute fibre gives rise to sufficient modulus to composites. → Outer or core material affect mechanical performance of hybrid composites. → Impact strength of pure EFB composite is higher than hybrid composites. - Abstract: Oil palm empty fruit bunches (EFB)/jute fibre reinforced epoxy hybrid composites with different sequence of fibre mat arrangement such as EFB/jute/EFB and jute/EFB/jute were fabricated by hand lay-up method. The effect of layering patterns on the mechanical performance of the composites was studied. The hybrid composites are intended for engineering applications as an alternative to synthetic fibre composites. Mechanical performance of hybrid composites were evaluated and compared with the pure EFB, pure jute composites and neat epoxy using flexural and impact testing. The flexural properties of hybrid composite is higher than that of pure EFB composite with respect to the weight fraction of fibre, where as the impact strength of pure EFB composite is much higher than those of hybrid composites. The flexural results were interpreted using sandwich theory. The fracture surface morphology of the impact testing samples of the hybrid composites was performed by scanning electron microscopy (SEM).

  7. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    Energy Technology Data Exchange (ETDEWEB)

    Misri, S; Leman, Z; Sapuan, S M; Ishak, M R, E-mail: sairizal_misri@yahoo.com [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2010-05-15

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  8. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    Science.gov (United States)

    Misri, S.; Leman, Z.; Sapuan, S. M.; Ishak, M. R.

    2010-05-01

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  9. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    International Nuclear Information System (INIS)

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  10. Thermal Properties of Jute Nano Fibre Reinforced Composites

    Directory of Open Access Journals (Sweden)

    K. T. B . Padal, K. Ramji, V. V. S. Prasad

    2014-05-01

    Full Text Available Polymer based nanocomposites have been subject of investigation by the dispersion of jute nanofibres within epoxy polymer matrix. Thermal properties of a composite play a vital role in evaluating the product performance as well as predicting the processibility characteristics in polymers in specific applications. The thermal behaviour of the interface between nanofibres reinforcement have been studied by thermogravemetric analysis and Differential scanning calorimetry. The addition of nanofibres with different weight percentages has been (1wt.% to 5wt.% studied and compared with base composites. The thermal stability of nanocomposite is significantly improved due to incorporation of jute nanofibres. These nanofibre reinforcement between the matrix resin molecules offered some resistance towards the thermal degradation.

  11. Recycling glass fibre-reinforced plastics in the automotive sector

    OpenAIRE

    Regenfelder, M.; Faller, J; Dully, S.; Perthes, H.; Williams, I. D.; den Boer, E.; Obersteiner, G.; Scherhaufer, S.

    2014-01-01

    The automotive sector is facing the challenge to become more resource-efficient in the manufacture of cars and their components. One approach is to increase the share of recycled materials. This paper presents the results of a case study for the automotive sector of the EU-funded Zerowin project. A safety-relevant component of the braking system was selected for manufacture using a mechanically recycled composite plastic material (polyethylene terephthalate reinforced with short glas...

  12. The Influence of Chemical Treatment on the Mechanical Behaviour of Animal Fibre-Reinforced High Density Polyethylene Composites

    Directory of Open Access Journals (Sweden)

    Isiaka O. Oladele

    2015-02-01

    Full Text Available This research work has investigated the influence of chemical treatment on the mechanical behaviour of animal fibre-reinforced high density polyethylene composites. The animal fibres used for this present study were chicken feather and cow hair fibres procured from local poultries and abattoirs. Prior to the development of the composite materials, the animal fibres were washed and dried, cut into 10 mm and divided into two portions; one portion was treated with 0.25 M NaOH maintained at 60 0C for 1 hour in a water bath, rinsed with distilled water and dried in the oven while the other portion was left untreated. Both portions were then used to reinforce the high density polyethylene polymer at 2, 4, 6, 8 and 10 % fibre loading respectively from which, the flexural and tensile test samples were produced by hot compression moulding. From the test results, it was observed that the chemically treated cow hair and chicken feather fibre reinforced high density polyethylene composites gave the best flexural properties for most fibre loading percentages compared to their untreated animal fibre-reinforced high density polyethylene composites counterparts and the neat high density polyethylene matrix. However, the tensile properties of all the animal fibre-reinforced high density polyethylene composites were not enhanced. Chicken feather and cow hair fibres were chosen for this research work to consider their potential applications as reinforcement for polymeric materials with a view to curtail the environmental pollution they generate by means of their disposal, as they are considered as unusable animal waste.

  13. Behaviour of -glass fibre reinforced vinylester resin composites under impact fatigue

    Indian Academy of Sciences (India)

    Rita Roy; B K Sarkar; N R Bose

    2001-04-01

    An impact fatigue study has been made for the first time on 63.5% glass fibre reinforced vinylester resin notched composites. The study was conducted in a pendulum type repeated impact apparatus especially designed and fabricated for determining single and repeated impact strengths. 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 fracture of fibre bundles at the compressive zone of the specimen. The residual strength, modulus and toughness showed retention of the properties at high impact stress levels up to 1000 impacts followed by a sharp drop. Cumulative residual stresses with each number of impacts not withstanding the static fatigue failure at long endurances have been ascribed for the composite failures under the repeated impact stresses.

  14. 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.

  15. Experimental study on the mechanical properties and microstructure of chopped basalt fibre reinforced concrete

    International Nuclear Information System (INIS)

    Highlights: • Effect of volume fraction and length of basalt fibre on concrete properties is tested. • Adding basalt fibre is found to improve mechanical properties of concrete. • A good bond between basalt fibre and matrix interface is observed in the early age by SEM. • MIP analysis shows basalt fibre concrete presents higher porosity. - Abstract: With high ductility and sufficient durability, fibre reinforced concrete (FRC) is widely used. In this study, the effects of the volume fraction and length of basalt fibre (BF) on the mechanical properties of FRC were analyzed. Coupling with the scanning electron microscope (SEM) and mercury intrusion porosimeter (MIP), the microstructure of BF concrete was studied also. The results show that adding BF significantly improves the tensile strength, flexural strength and toughness index, whereas the compressive strength shows no obvious increase. Furthermore, the length of BF presents an influence on the mechanical properties. Compared with the plain concrete, the compressive, splitting tensile and flexural strength of concrete reinforced with 12 mm BF increase by −0.18–4.68%, 14.08–24.34% and 6.30–9.58% respectively. As the BF length increasing to 22 mm, corresponding strengths increase by 0.55–5.72%, 14.96–25.51% and 7.35–10.37%, separately. A good bond between the BF and the matrix interface is observed in the early age. However, this bond shows degradation to a certain extent at 28 days. Moreover, the MIP results indicate that the concrete containing BF presents higher porosity

  16. Use of synthetic fibre reinforcement for improving the performance of AGM separators for VRLA batteries

    Science.gov (United States)

    Clement, N.

    Absorbent material made of 100% microglass fibre is well-known as a separator for valve-regulated lead-acid (VRLA) batteries and has been in use for about 20 years. As the VRLA battery market and demands on battery performance continue to grow, the electrical characteristics, productivity and reliability of VRLA batteries are being enhanced. Both the reliability and the electrical performance of the battery are linked to the AGM glass material. The properties of the AGM material impact the assembly route, defect rates, productivity, product cycleability, life, reliability, and recharge performance. An AGM product range which contains synthetic fibres up to 30% in mass (the remaining 70% is still glass) has been developed. The reinforcement of the material with a specific organic fibre is showing very positive effects, both on intrinsic separator characteristics and, as a consequence, on the manufacturing, electrical properties and cycle-life of batteries. The AGM product has been used in the battery market now for more than 20 years. Based on this experience, new testing methods such as the fatigue test and internal pressure measurement have been developed. It is clear from such measurements that reinforcement with synthetic fibre has a positive impact on battery characteristics.

  17. Rehabilitation of concrete structures using Ultra-High Performance Fibre Reinforced Concrete

    OpenAIRE

    Brühwiler, E.; Denarié, E.

    2008-01-01

    An original concept is presented for the rehabilitation of concrete structures. The main idea is to use Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) to “harden” those zones where the structure is exposed to severe environmental and high mechanical loading. All other parts of the structure remain in conventional structural concrete as these parts are subjected to relatively moderate exposure. This conceptual idea combines efficiently protection and resis-tance properties of UHPFRC...

  18. 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

  19. Metal Triflates as Catalytic Curing Agents in Self-Healing Fibre Reinforced Polymer Composite Materials

    OpenAIRE

    Coope, Timothy S; Wass, Duncan F; Trask, Richard S.; Bond, Ian P.

    2014-01-01

    A self-healing, high performance, fibre reinforced polymer (FRP) composite material is demonstrated by employing a Lewis acid-catalysed epoxy self-healing agent (SHA) within a laminate manufactured using existing industrial methods. Thermal cure analysis and mechanical testing is employed to characterise the self-healed polymer. A bio-inspired series of vascules incorporated into an FRP composite material facilitates the delivery of SHAs to exposed fractured crack planes. Healing is effected ...

  20. Improvement of Serviceability and Strength of Textile Reinforced Concrete by using Short Fibres

    OpenAIRE

    Hinzen, Marcus; Brameshuber, Wolfgang

    2009-01-01

    Nowadays, thin-walled load bearing structures can be realised using textile reinforced concrete (BRAMESHUBER and RILEM TC 201-TRC [1]). The required tensile strength is achieved by embedding several layers of textile. By means of the laminating technique the number of textile layers that can be included into the concrete could be increased. To further increase the first crack stress and the ductility as well as to optimize the crack development, fine grained concrete mixes with short fibres c...

  1. Flexural response of polypropylene/E-glass fibre reinforced unidirectional composites

    OpenAIRE

    Okereke, Michael I

    2016-01-01

    This paper presents a study of the flexural response of continuous E-glass fibre reinforced polypropylene composites. Experiments were designed to investigate monotonic and cyclic flexural response using three point bending test for laminates with different angle-ply and cross-ply arrangements. Results show that the monotonic and cyclic flexural response of the composites are influenced by the plastic deformation of the matrix. The study observed that increasing numbers of cyclic loads led to...

  2. Application of steel fibre reinforced sprayed concrete to a deep tunnel in weak rocks

    Institute of Scientific and Technical Information of China (English)

    周宏伟; 彭瑞东; 李振东; 董正亮; 陈文伟; 王健

    2002-01-01

    Based on an engineering background of a deep tunneling in weak rocks, the numerical modeling is used to compare different support schemes of tunnel at great depth in this paper. Focused on the general behaviors of weak rocks at great depth, a tunneling scheme with rock bolting and steel fibre reinforced sprayed concrete is proposed. This scheme is practiced successfully at a deep tunnel in weak rocks in Coal Mine No.10 of Hebi Coal Mining Administration.

  3. Prediction of stiffness and stresses in z-fibre reinforced composite laminates

    OpenAIRE

    Grassi, Marcello; Zhang, Xiang; Meo, Michele

    2002-01-01

    The mechanical properties of z-pinned composite laminates were examined numerically. Finite element calculations have been performed to understand how the through-thickness reinforcement modifies the engineering elastic constants and local stress distributions. Solutions were found for four basic laminate stacking sequences, all having two percent volume fraction of z-fibres. For the stiffness analysis, a micromechanicalfinite element model was employed that was based on the...

  4. Shrinkage of polypropylene fibre reinforced high strength concrete

    OpenAIRE

    Zajec, Matija

    2012-01-01

    In this diploma paper we deal with the analysis of high strength concrete, micro-reinforced with polypropylene fibers. We used four different lengths of polypropylene fibers: 6mm, 12 mm, 18 mm and 30 mm. The share of fibers in each concrete mixture is 0.5 % of the total volume. With high strength concretes autogenous shrinkage is very intensive, so the first day we measured it electronically with dial gauges. Later we measured the shrinking with a mobile displacement transducer. We measured a...

  5. Calibration of an image processing tool for analysis of fibre orientation in fibre reinforced composites

    Czech Academy of Sciences Publication Activity Database

    Hos, J.; Doktor, T.; Petráňová, Veronika; Kytýř, Daniel

    Praha: Czech Technical University in Prague, Faculty of Transportation Sciences, 2014 - (Kytýř, D.; Zlámal, P.; Růžička, M.), s. 48-51 ISBN 978-80-01-05556-4. [Youth symposium on experimental solid mechanics /13./. Děčín (CZ), 29.06.2014-02.07.2014] R&D Projects: GA TA ČR(CZ) TA03010209 Institutional support: RVO:68378297 Keywords : C/PPS * fibre orientation * SEM * composite Subject RIV: JI - Composite Materials http://www.itam.cas.cz/ysesm2014/proceedings/id_28_ysesm2014_proceedings.pdf

  6. 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.

  7. Mechanical properties and in vitro degradation of self-reinforced radiopaque bioresorbable polylactide fibres.

    Science.gov (United States)

    Nuutinen, Juha-Pekka; Clerc, Claude; Törmälä, Pertti

    2003-01-01

    The aim of this study was to evaluate the effect of the radiopaque filler, barium sulfate (BaSO4), on the mechanical properties of self-reinforced bioresorbable fibres. The bioresorbable polymer was a copolymer of L- and D-lactide with an L/D monomer ratio of 96:4 (96L/4D PLA). The fibres were manufactured using an extrusion and a drawing process. Three different methods of processing the composites were studied. The materials were blended prior to extrusion. In the first method, the BaSO4 powder was mixed with the polymer granulates by hand (manual blending). The blend was then processed using a twin-screw extruder. The second and third methods utilized a single-screw extruder. In the second method, the BaSO4 powder was manually mixed with the polymer prior to extrusion. In the third method, the BaSO4 powder was mechanically attached on the polymer granulates (mechanical blending) prior to extrusion. The mechanical and chemical properties of the radiopaque bioresorbable fibres were measured after processing and during in vitro degradation. The fibres were gamma, plasma or EtO sterilized. There was no statistical difference in the mechanical properties of the fibres when manufactured using the twin-screw extrusion with manual blending or the single-screw extrusion with mechanical blending. The gamma sterilization markedly decreased the initial intrinsic viscosity of all fibres, whereas the plasma and EtO sterilization methods had no effect on the initial intrinsic viscosity. During in vitro testing, the loss in the intrinsic viscosity occurred at the same rate whether the fibres were loaded with the barium sulfate or not. PMID:12903735

  8. Strengthening of reinforced concrete circular columns using glass fibre reinforced polymers

    OpenAIRE

    Manish kumar Tiwari; Rajiv Chandak

    2014-01-01

    Seismic retrofitting of reinforced concrete members vulnerable to strong earthquakes is a great problem. It has long been recognized that confinement to concrete compression members not only increase the strength but improve ductility significantly. The present study focuses on the behavior of reinforced concrete specimens strengthened using glass fiber reinforced polymer (GFRP) subjected to axial compressive loading. In this study specimen of circular cross section having len...

  9. Experimental Studies on Impact Characteristics of Steel Fibre Reinforced Concretes

    Directory of Open Access Journals (Sweden)

    K. Anbuvelan

    2014-10-01

    Full Text Available Research work carried out so far towards the development of concrete that exhibits improved impact resistance than conventional concrete. There are several situations in which concrete structural elements are subjected to impact loading. The behaviour of concrete under impact loads is far from adequate and there is significant variability in the published literature. The primary reason for this is the lack of a standardized technique of testing concrete under impact. In this project, an attempt is made to study the impact resistance of fibrous concrete using ACI drop weight Impact tester. Two grades of concrete’s namely M1 and M2 are consideredin this investigation with 0.5, 1.0, 1.5 and 2.0% dosage of steel fiber. The experimental test results of steel reinforced fiber concrete are compared with plain concrete and conclusions are arrived.

  10. Effect of Sea Water and Natural Ageing on Residual Strength of Epoxy Laminates, Reinforced with Glass and Carbon Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Andrzej Komorek

    2016-01-01

    Full Text Available This paper reports the results of the effect of sea water, natural ageing, and cross-impact loading on flexural strength and residual flexural strength of epoxy laminates with glass woven fabrics and hybrid reinforcement with glass and carbon woven fabrics. The tests were conducted on samples with different fibre reinforcement both before and after low energy cross-impact loading. Carbon fabrics decreased residual strength of the composites.

  11. Influence of cyclic freeze-thaw on the parameters of the electric response to the pulse mechanical excitation of concrete reinforced by glass fibre reinforced polymer bars

    Science.gov (United States)

    Fursa, T. V.; Petrov, M. V.; Korzenok, I. N.

    2016-02-01

    Studies of the influence of cyclic freeze-thaw on the parameters of electric response from samples of concrete reinforced by glass fibre reinforced polymer (GFRP) bars were conducted. It is found that an increase in the number of freeze-thaw cycles increases the attenuation coefficient of energy of electric responses and moves the centre of gravity of spectrum to the low-frequency area. The results can be used to develop a method of nondestructive testing of reinforced concrete.

  12. The Influence of Chemical Treatment on the Mechanical Behaviour of Animal Fibre-Reinforced High Density Polyethylene Composites

    OpenAIRE

    Isiaka O. Oladele; Jimmy L. Olajide; Adekunle S. Ogunbadejo

    2015-01-01

    This research work has investigated the influence of chemical treatment on the mechanical behaviour of animal fibre-reinforced high density polyethylene composites. The animal fibres used for this present study were chicken feather and cow hair fibres procured from local poultries and abattoirs. Prior to the development of the composite materials, the animal fibres were washed and dried, cut into 10 mm and divided into two portions; one portion was treated with 0.25 M NaOH maintained at 60 0C...

  13. Radiation-curing of acrylate composites including carbon fibres: A customized surface modification for improving mechanical performances

    Science.gov (United States)

    Martin, Arnaud; Pietras-Ozga, Dorota; Ponsaud, Philippe; Kowandy, Christelle; Barczak, Mariusz; Defoort, Brigitte; Coqueret, Xavier

    2014-12-01

    The lower transverse mechanical properties of radiation-cured acrylate-based composites reinforced with carbon-fibre with respect to the thermosettable analogues was investigated from the viewpoint of chemical interactions at the interface between the matrix and the carbon material. XPS analysis of representative commercial carbon fibres revealed the presence of a significant amount of chemical functions potentially exerting an adverse effect on the initiation and propagation of the free radical polymerization initiated under high energy radiation. The EB-induced polymerization of n-butyl acrylate as a simple model monomer was conducted in the presence of various aromatic additives exhibiting a strong inhibiting effect, whereas thiols efficiently sensitize the initiation mechanism and undergo transfer reactions. A method based on the surface modification of sized fibres by thiomalic acid is proposed for overcoming the localized inhibition phenomenon and for improving the mechanical properties of the resulting acrylate-based composites.

  14. Scale-up activation of carbon fibres for hydrogen storage

    OpenAIRE

    Kunowsky, Mirko; Marco Lozar, Juan Pablo; Cazorla Amorós, Diego; Linares Solano, Ángel

    2009-01-01

    In a previous study, we investigated, at a laboratory scale, the chemical activation of two different carbon fibres (CF), their porosity characterization, and their optimization for hydrogen storage [1]. In the present work, this study is extended to: (i) a larger range of KOH activated carbon fibres, (ii) a larger range of hydrogen adsorption measurements at different temperatures and pressures (i.e. at room temperature, up to 20 MPa, and at 77 K, up to 4 MPa), and (iii) a scaling-up activat...

  15. Explosive emission cathode on the base of carbon plastic fibre

    International Nuclear Information System (INIS)

    A fabrication process for explosive emission cathodes on the base of carbon plastic fibre of practically any geometrical shape and dimensions is developed. Experimental studies of electron beam current collection from cathodes, 2cm in diameter, at voltages across the diode of 10 and 150-250kV. It is shown that the ignition voltage for cathode plasma is ∼2kV at the interelectrode diode gap of 5mm and residual gas pressure of ∼5x10-5Torr. The carbon-fibre cathode, fabricated in this way, provides more stable current collection of an electron beam (without oscillations) than other cathodes

  16. Atmospheric pressure plasma surface modification of carbon fibres

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Løgstrup Andersen, Tom; Michelsen, Poul

    2008-01-01

    Carbon fibres are continuously treated with dielectric barrier discharge plasma at atmospheric pressure in various gas conditions for adhesion improvement in mind. An x-ray photoelectron spectroscopic analysis indicated that oxygen is effectively introduced onto the carbon fibre surfaces by He, He...... temperature for a month the O/C ratio at the plasma treated surfaces decreased to 0.151, which is close to that of the untreated ones. It can be attributed to the adsorption of hydrocarbon contamination at the plasma treated surfaces....

  17. The effect of surface treatment on the interfacial properties in carbon fibre/epoxy matrix composites

    OpenAIRE

    Bogoeva-Gaceva, Gordana; Janevski, Aco; Dekanski, Aleksandar; D. BUREVSKI

    1995-01-01

    Carbon fibres with different degrees of surface oxidation, as well as epoxy-sized fibres, were used to prepare epoxy composites in order to compare the effects of the fibres surface chemistry on the interfacial properties. X-ray photoelectron spectroscopy, water vapour adsorption measurements and contact angle examination were applied to characterize the carbon fibre surfaces. A correlation was found between the content of primary adsorption sites on the fibre surface and interlaminar shear s...

  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)

    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. DEPOSITION OF NICKEL ON CARBON FIBRES BY GALVANIC METHOD

    Directory of Open Access Journals (Sweden)

    Pavol Štefánik

    2012-01-01

    Full Text Available The investigation of coating parameters in quasi-static coating of Ni layer on carbon fibre tow by galvanic method is presented. The tow of fibres was immersed in typical galvanic bath based on NiSO4, NiCl2, Na2SO4 and H3BO3 and current to carbon fibres was supplied by two leading metal rolls which are parts of continuous coating apparatus. The main parameters were current of 1 A, electrolyte temperature of 50 °C and the distance from power contacts to level of galvanic bath (8 or 13 cm. The amount and structure of deposited Ni layer at coating time 15 and 90 seconds of exposure in electrolyte and depth of immersion of tow into bath were discussed.

  2. 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

    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......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...

  3. Fatigue testing of a carbon fibre composite wind turbine blade with associated material characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, G.A.; Richardson, D.J. [Univ. of the West of England, Faculty of Engineering, Bristol (United Kingdom)

    1996-09-01

    Within the EC project JOULE 2, the University of the West of England (UWE) tested a carbon fibre reinforced epoxy (CFRE) full scale wind turbine blade together with an associated material test coupon programme. All the work was closely linked with the manufacturer Polymarine BV of the Netherlands, who designed and manufactured the blade and provided test specimens, the UWE carried out the research into the validation of the design calculations together with a check of the strength and fatigue life of the blade. (au)

  4. Stiffness Characteristics of Fibre-reinforced Composite Shaft Embedded with Shape Memory Alloy Wires

    Directory of Open Access Journals (Sweden)

    K. Gupta

    2003-04-01

    Full Text Available Frequent coast up/coast down operations of rotating shafts in the power and aerospace industry expose the flexible rotors to the risk of fatigue failures. Resonant vibrations during passage through critical speeds induce large stresses that may lead to failures. In this paper, the use of nitinol [shape memory alloy (SMA] wires in the fibre-reinforced composite shaft, for the purpose ofmodifying shaft stiffness properties to avoid such failures, is discussed. A setup has been developed to fabricate the composite shaft (made of fibre glass and epoxy resin embedded with pre-stressed SMA wires. Experiments have been carried out on the shaft to estimate the changes in the natural frequency of the composite shaft due to activation and deactivation ofSMA wires. The comparisonofthe experimental results with the established analytical results indicates feasibility ofvibration control using the special properties of SMA wires.

  5. Self-healing of damage in fibre-reinforced polymer-matrix composites

    OpenAIRE

    Hayes, S.A; Zhang, W; Branthwaite, M; Jones, F R

    2007-01-01

    Self-healing resin systems have been discussed for over a decade and four different technologies had been proposed. However, little work on their application as composite matrices has been published although this was one of the stated aims of the earliest work in the field. This paper reports on the optimization of a solid-state self-healing resin system and its subsequent use as a matrix for high volume fraction glass fibre-reinforced composites. The resin system was optimized using Charpy i...

  6. Effect of nanoparticles on tensile, impact and fatigue properties of fibre reinforced plastics

    Indian Academy of Sciences (India)

    R Nagalingam; S Sundaram; B Stanly Jones Retnam

    2010-10-01

    Advanced composite, fibre-reinforced polymer (FRP), has been favoured for certain aerospace, military, marine and automotive applications. Polymer nanocomposites containing layered silicates have attracted much attention. These exhibit increased modulus, decreased thermal expansion coefficient, increased solvent resistance and enhanced ionic conductivity when compared to the polymer alone. Here we have developed eight different combinations of composites FRP with nanoclay (montmorillonite) by layered manufacturing techniques (LM) and measured the mechanical properties. The measurement showed that the tensile strength, impact strength and fatigue life are greatly increased. A plausible explanation for high increase of properties has also been discussed.

  7. An engineering analysis of penetration of metal ball into fibre-reinforced composite targets

    Institute of Scientific and Technical Information of China (English)

    Yong-chi LI; Zhi-hai WANG; Xiao-jun WANG; Xiu-zhang HU

    2009-01-01

    An engineering analysis of computing the penetration problem of a steel ball penetrating into fibre-reinforced composite targets is presented. Assume the metal ball is a rigid body, and the composite target is a transversely isotropic elasto-plastic material. In the analysis, a spherical cavity dilatation model is incorporated in the cylindrical cavity penetration method. Simulation results based on the modified model are in good agreement with the results for 3-D Kevlar woven (3DKW) composite anti-penetration experiments. Effects of the target material parameters and impact parameters on the penetration problem are also studied.

  8. Elastic properties of silica-silica continuous fibre-reinforced, ceramic matrix composites

    International Nuclear Information System (INIS)

    Ambient and elevated temperature elastic properties of silica-silica ceramic fibre-reinforced, ceramic-matrix composites (silica-silica CFCCs), obtained using resonance beam technique, have been reported and discussed. The composite exhibits in-plane isotropy and through-thickness anisotropy in the elastic properties at ambient temperatures and increasing elastic moduli with increasing test temperature. The latter results are attributable to the change in the nature of atomic bonding of the silica material up to about 1173 K and further increase in moduli with temperature is due to the combined effects of devitrification and densification due to sintering

  9. Gliding arc surface treatment of glass fibre reinforced polyester enhanced by ultrasonic irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Bardenshtein, Alexander;

    2010-01-01

    polar functional groups were introduced at the surface by the gliding arc treatment, and that the treatment efficiency was enhanced by the ultrasonic irradiation, indicating that the adhesive property would be improved. The results are extensively discussed in terms of the plasma conditions, and the...... irradiation onto the surface. In the present work glass fibre reinforced polyester (GFRP) plates are treated using an atmospheric pressure gliding arc discharge with and without ultrasonic irradiation to study adhesion improvement. The gliding arc was generated between divergent electrodes by utilizing an...

  10. Thermogravimetric analysis of aluminised E-glass fibre reinforced unsaturated polyester composites

    OpenAIRE

    Ferreira, J. M.; Errajhi, O. A. Z.; Richardson, M.O.W

    2006-01-01

    Novel aluminised E-glass fibre reinforced unsaturated polyester composites, originally formulated for enhanced thermal and electrical shielding properties were evaluated in terms of their thermal performance. The thermal degradation of these specimens was analysed using a thermogravimetric analyser (TGA). The samples were heated from ambient temperature to 500 °C at a heating rate of 20 °C/min. All specimens were decomposed under dry nitrogen (N2) at a flow rate of 40 ml/min to yield gases an...

  11. COMMERCIAL VIABILITY ANALYSIS OF LIGNIN BASED CARBON FIBRE

    OpenAIRE

    Michael Chien-Wei Chen

    2014-01-01

    Lignin is a rich renewable source of aromatic compounds. As a potentialpetroleum feedstock replacement, lignin can reduce environmental impacts such ascarbon emission. Due to its complex chemical structure, lignin is currently underutilized.Exploiting lignin as a precursor for carbon fibre adds high economic value to lignin andencourages further development in lignin extraction technology. This report includes apreliminary cost analysis and identifies the key aspects of lignin-based carbon fi...

  12. Strengthening of reinforced concrete circular columns using glass fibre reinforced polymers

    Directory of Open Access Journals (Sweden)

    Manish kumar Tiwari

    2014-04-01

    Full Text Available Seismic retrofitting of reinforced concrete members vulnerable to strong earthquakes is a great problem. It has long been recognized that confinement to concrete compression members not only increase the strength but improve ductility significantly. The present study focuses on the behavior of reinforced concrete specimens strengthened using glass fiber reinforced polymer (GFRP subjected to axial compressive loading. In this study specimen of circular cross section having length to diameter ratio of 2.0 and 0.96% longitudinal reinforcement were prepared and tested for 28 days compressive strength. The specimens were wrapped with 0,2,4,6 and 8 layers of GFRP outside the surface of the specimens as confinement. The test results showed that there is a significant increase in the strength of specimen with the increase of confinement layers on the specimen. The 28 days compressive strength of specimen wrapped with 8 layers of GRRP was increased by 47% as compared to the strength of specimen without any confinement.

  13. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    OpenAIRE

    Mehran Tehrani; Ayoub Yari Boroujeni; Claudia Luhrs; Jonathan Phillips; Al-Haik, Marwan S.

    2014-01-01

    Carbon nanofilament and nanotubes (CNTs) have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs) and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers emplo...

  14. Impact of chemical treatments on the mechanical and water absorption properties of coconut fibre (Cocos nucifera reinforced polypropylene composites

    Directory of Open Access Journals (Sweden)

    Isiaka O. OLADELE

    2016-07-01

    Full Text Available In this work, chemically treated coconut fibres were used to reinforce Homopolymer Polypropylene in order to ascertain the effect of the treatments on the mechanical and water absorption properties of the composites produced. Coconut fibre was first extracted from its husk by soaking it in water and was dried before it was cut into 10 mm lengths. It was then chemically treated in alkali solution of sodium hydroxide (NaOH and potassium hydroxide (KOH in a shaker water bath. The treated coconut fibres were used as reinforcements in polypropylene matrix to produce composites of varied fibre weight contents; 2, 4, 6, 8 and 10 wt.%. Tensile and flexural properties were investigated using universal testing machine while water absorption test was carried out on the samples for 7 days. It was observed from the results that, NaOH treated samples gave the best tensile properties while KOH treated samples gave the best flexural and water repellent properties.

  15. The influence of compliant chassis components on motorcycle dynamics: an historical overview and the potential future impact of carbon fibre

    Science.gov (United States)

    Lake, Kelvin; Thomas, Richard; Williams, Owen

    2012-07-01

    This paper details the influence of compliant chassis components on motorcycle dynamics. Initially, research which has previously been carried out in terms of motorcycle dynamics and in particular the impact of compliant chassis components on motorcycle dynamics is discussed. This paper then considers the consequences of these findings with regard to the use of modern materials such as carbon fibre reinforced plastics and the impact they will potentially have on motorcycle dynamics and its simulation.

  16. Roughness Influence On Macro- And Micro-Tribology Of Multi-Layered Hard Coatings On Carbon Fibre Polymer Composite

    OpenAIRE

    Lackner J. M.; Major B.; Waldhauser W.; Mzyk A.; Major Ł.; Kot M.

    2015-01-01

    Goal of this work is the investigation of roughness influences on the abrasive wear behaviour of magnetron sputtered multi-layered, low-friction coatings on carbon-fibre reinforced polymers (CFRP). Higher coating roughness at similar CFRP quality was realized by higher deposition rates, leading to increased heat flux to the substrates during deposition. Thermal expansion of the epoxy matrix on the micro scale results in a wavy, wrinkled surface topography. Both in scratch and reciprocal slidi...

  17. Evaluation of hyperelastic models for unidirectional short fibre reinforced materials using a representative volume element with refined boundary conditions

    OpenAIRE

    Goldberg, N.; Donner, H.; Ihlemann, J.

    2014-01-01

    The simulation of a short fibre reinforced structure by means of the FEM requires the knowledge of the material behaviour at every Gauss point. In order to obtain such information, a representative volume element (RVE) containing unidirectional short fibres is analysed in the presented work. The findings are used to assess the applicability of several hyperelastic models describing transversal isotropic materials under consideration of large deformations. As the RVE's average response represe...

  18. Strength and Toughness of Steel Fibre Reinforced Reactive Powder Concrete Under Blast Loading

    Institute of Scientific and Technical Information of China (English)

    KUZNETSOV Valerian A; REBENTROST Mark; WASCHL John

    2006-01-01

    The blast resistance of structures used in buildings needs to be investigated due to the increased threat of a terrorist attack.The damage done by Composition B or Powergel to steel fibre reinforced reactive powder concrete (SFRPC) panels and ordinary reinforced concrete (RC) panels of equivalent static flexural strength is compared.A 0.5 kg charge was detonated at a distance of 0.1 m from the 1.3 m × 1.0 m × 0.1 m (thick) panels,which were simply supported and spaning 1.3 m.Dynamic displacement measurements,high-speed video recording and visual examination of the panels for spall and breach were undertaken.The SFRPC panels withstood the bare charge blast better than the reinforced ordinary concrete panels.Neither type of panel was breached using a 0.5 kg charge.The RC panel exhibited more spalling when Composition B was used.Under successive Composition B loading conditions,the RC panel was breached.In comparison the SFRPC panel was not breached.Exposure to fragmenting charge loading conditions confirmed these performance differences between the SFRPC panel and the reinforced ordinary concrete panel.

  19. Comparison of Performance of Standard Concrete And Fibre Reinforced Standard Concrete Exposed To Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    K.Srinivasa Rao

    2013-01-01

    Full Text Available Concrete elements exposed to fire undergo temperature gradients and as a result, undergo physical changes or spalling which leads to expose steel reinforcement. This causes distress in concrete structures. The performance of concrete can be improved with the addition of steel fibres to concrete especially when it is exposed to heat. Therefore, this study has been carried out to generate experimental data on standard concrete ofgrade M45 and Fiber Reinforced Standard Concrete exposed to elevated temperatures. For each type of concrete six sets of cubes, cylinders, and beams have been cast. Each set contains 5specimens. A total of thirty cubes, thirty cylinders, and thirty beams of Standard Concrete and Fiber Reinforced Standard Concrete have been cast, out of which 5 sets of standard concrete and fiber reinforced standard concrete are exposed to elevated temperatures of 500C, 1000C, 1500C, 2000C and 2500C for 3 hours and the sixth set is tested at room temperature as control concrete. These specimens have been tested for compressive strength, split tensile strength, and flexural strength in hot condition immediately after taking out from oven. The results are analyzed and final conclusions are drawn.

  20. 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

  1. 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

  2. Strengthening of 230KV wood transmission structures with glass fibre reinforced polymer (GFRP) wraps

    Energy Technology Data Exchange (ETDEWEB)

    Shahi, A.; West, J.S.; Pandey, M.D. [Waterloo Univ., ON (Canada). Dept. of Civil Engineering

    2007-07-01

    In northern Canada, an unexpected structural failure resulting from wood deterioration has been determined to pose a risk to the safety of the 230 kV wood transmission lines. Because of the remote location of the transmission structures and the need to keep the transmission lines in continuous service, replacement of deteriorated elements can be very expensive. One potential alternative is to install a lightweight strengthening system while the old structure is being serviced. One of the most common structural repair systems are fibre reinforced polymer (FRP) materials. Limited research has explored the feasibility of this strengthening system on wood beams. This paper presented a pilot experimental research program to study the feasibility of using Glass Fibre Reinforced Polymer (GFRP) fabrics as a lightweight, reliable, and effective strengthening system for deteriorated circular cross-arms of the Gulfport transmission structures. The paper discussed previous research on FRP materials, the research strategy of this study, the experimental program, and experimental results and analysis. This included measured moisture content, failure mode, relationship between stiffness and failure load, effect of wrapping on strength, and the effect of wrapping on stiffness. The results of the experimental program suggested a strong correlation between the failure load and the stiffness of the specimens and that the proposed strengthening system could result in more consistent strengths. 9 refs., 2 tabs., 8 figs.

  3. Study of the performances of acoustic emission testing for glass fibre reinforced plastic pipes containing defects

    International Nuclear Information System (INIS)

    Glass fibre reinforced plastic pipes are more and more often used, in nuclear power plants, for building or replacement of water pipings classified 'nuclear safety'. Tests have been performed to evaluate the performances of acoustic emission testing for in service inspection of these components. The tests were focused on glass fibre reinforced polyester and vinyl-ester pipes, in as received conditions or containing impacts, and intentionally introduced defects. They have been carried out by CETIM, following the ASTM Standard E 1118 (code CARP), to a maximum pressure lever of 25 Bar The results show that the CARP procedure can be used for detection of defects and evaluation of their noxiousness towards internal pressure: most of the tubes containing low energy impacts could not be distinguished from tubes without defect; on the other hand the important noxiousness of lacks of impregnation of roving layer appeared clearly. Complementary tests have been performed on some tubes at a more important pressure lever, for which the damage of the tubes in enough to deteriorate there elastic properties. The results showed that CARP procedure give valuable informations on damage level. It would be interesting to evaluate acoustic emission on tubes containing realistic in-service degradations. (author). 11 refs., 15 figs., 6 tabs., 2 appends

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Carbon fibre composite for ventilation air methane (VAM) capture

    International Nuclear Information System (INIS)

    Coal mine methane (CMM) is not only a hazardous greenhouse gas but is also a wasted energy resource, if not utilised. This paper evaluates a novel adsorbent material developed for capturing methane from ventilation air methane (VAM) gas in underground coal mines. The adsorbent material is a honeycomb monolithic carbon fibre composite (HMCFC) consisting of multiple parallel flow-through channels and the material exhibits unique features including low pressure drop, good mechanical properties, ability to handle dust-containing gas streams, good thermal and electrical conductivity and selective adsorption of gases. During this study, a series of HMCFC adsorbents (using different types of carbon fibres) were successfully fabricated. Experimental data demonstrated the proof-of-concept of using the HMCFC adsorbent to capture methane from VAM gas. The adsorption capacity of the HMCFC adsorbent was twice that of commercial activated carbon. Methane concentration of 0.56% in the inlet VAM gas stream is reduced to about 0.011% after it passes through the novel carbon fibre composite adsorbent material at ambient temperature and atmospheric pressure. This amounts to a maximum capture efficiency of 98%. These encouraging laboratory scale studies have prompted further large scale trials and economic assessment.

  9. Vibrations of carbon nanotube-reinforced composites

    Science.gov (United States)

    Formica, Giovanni; Lacarbonara, Walter; Alessi, Roberto

    2010-05-01

    This work deals with a study of the vibrational properties of carbon nanotube-reinforced composites by employing an equivalent continuum model based on the Eshelby-Mori-Tanaka approach. The theory allows the calculation of the effective constitutive law of the elastic isotropic medium (matrix) with dispersed elastic inhomogeneities (carbon nanotubes). The devised computational approach is shown to yield predictions in good agreement with the experimentally obtained elastic moduli of composites reinforced with uniformly aligned single-walled carbon nanotubes (CNTs). The primary contribution of the present work deals with the global elastic modal properties of nano-structured composite plates. The investigated composite plates are made of a purely isotropic elastic hosting matrix of three different types (epoxy, rubber, and concrete) with embedded single-walled CNTs. The computations are carried out via a finite element (FE) discretization of the composite plates. The effects of the CNT alignment and volume fraction are studied in depth to assess how the modal properties are influenced both globally and locally. As a major outcome, the lowest natural frequencies of CNT-reinforced rubber composites are shown to increase up to 500 percent.

  10. 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)

    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

  11. Unidirectional Cordenka Fibre-Reinforced Furan Resin Full Biocomposite: Properties and Influence of High Fibre Mass Fraction

    OpenAIRE

    Talent Malaba; Jiajun Wang

    2015-01-01

    A full biocomposite was fabricated from Cordenka CR fibre and furan resin. High fibre mass fractions (FMF) were achieved by pressing the CR fibres into unidirectional sheets prior to incorporation into the resin. Results of testing indicated that the tensile properties of the biocomposite were improved by the initial increase of FMF from 51 to 64%, with a subsequent increase of FMF to 75% resulting in a deterioration of those properties. Examination of the tensile fracture surfaces with a sca...

  12. Go with the flow: conservation of a floating sculpture from 1961 made from glass fibre-reinforced polyester resin

    NARCIS (Netherlands)

    L. Beerkens; S. Stigter; T. van Oosten; H. van Keulen

    2007-01-01

    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 c

  13. 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.

  14. Optimization of microwire/glass-fibre reinforced polymer composites for wind turbine application

    Science.gov (United States)

    Qin, F. X.; Peng, H. X.; Chen, Z.; Wang, H.; Zhang, J. W.; Hilton, G.

    2013-11-01

    We here report a comprehensive study of glass-fibre reinforced polymers (GFRP) incorporating ferromagnetic microwires for microwave absorption applications. With wire addition, a remarkable dependence of microwave absorption performance appears on the local properties of wires such as wire geometry and the mesostructure such as inter-wire spacing, as well as the embedded depth of the wires layer. The impact testing further demonstrates that the metallic microwires can to some extent improve the impact performance. Based on both the absorption and impact behavior, we propose an optimized design of the microwire/GFRP composites to achieve simultaneous best possible absorption and impact performance for multifunctional applications in aeronautical structures and wind turbines.

  15. Plasma Surface Modification of Glass-Fibre-Reinforced Polyester Enhanced by Ultrasonic Irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Bardenshtein, Alexander;

    2010-01-01

    .295, 0.385 and 0.447, respectively. This indicated that the plasma treatment oxidized and roughened the GFRP surface, and the ultrasonic irradiation further enhanced the oxidation. It is concluded that plasma treatment efficiency for adhesion improvement of GFRPs is enhanced by the ultrasonic irradiation.......During atmospheric pressure plasma treatment, reactive species generated in the plasma diffuse through a boundary gas layer which is adsorbed at the material surface. Many of the reactive species become inactivated before reaching the surface due to their short lifetime. The efficiency of plasma...... treatment can be highly enhanced by simultaneous high-power ultrasonic irradiation of the treating surface, because the delivered acoustic energy can reduce the thickness of the boundary gas layer. Here surfaces of glass-fibre-reinforced polyester (GFRP) plates were treated using an atmospheric pressure...

  16. 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

    approximately from 20 mJ m-2 up to 80 mJ m-2 with ultrasonic irradiation. The plasma treatment with ultrasonic irradiation also introduced oxygen and nitrogen containing functional groups at the GFRP surface. These changes would improve the adhesion properties of the GFRP plates.......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...... 30 kHz with the sound pressure level of approximately 155 dB were introduced vertically to the GFRP surface through a cylindrical waveguide. The polar component of the surface energy was almost unchanged after the plasma treatment without ultrasonic irradiation, but drastically increased...

  17. Adhesion improvement of glass-fibre-reinforced polyester composites by gliding arc discharge treatment

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom;

    2013-01-01

    A gliding arc is a plasma that can be operated at atmospheric pressure and applied for plasma surface treatment for adhesion improvement. In the present work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding arc discharge with an air flow to improve...... adhesion with a vinylester adhesive. The treatment improved wettability and increased the polar component of the surface energy and the density of oxygen-containing polar functional groups at the surfaces. Double cantilever beam specimens were prepared for fracture mechanics characterisation (fracture...... resistance as a function of nominal mode mixity) of the laminate adhesive interface. It was found that gliding arc treatment significantly increases the interfacial fracture energy and fracture resistance in comparison with a standard peel ply treatment, although the mixed mode fracture energy of the gliding...

  18. 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. In...... order to estimate performances, detailed thermal calculations were performed in four successive steps including solar energy and light transmittance in addition to heat loss and supplemented with a simplified structural calculation of frame load capacity and deflection. Based on these calculations, we...... 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 of...

  19. Lightweight self-compacting concrete reinforced with fibres for slab rehabilitation

    International Nuclear Information System (INIS)

    The slabs of some buildings in Barcelona are formed by unidirectional beams, with a ceramic arch in between, which are filled with broken pottery or construction waste. These structures often present problems such as displacement of the tiles arranged over it due to the lack of stiffness of the filling material. This supposes a risk to the user and could also cause durability problems. In order to rehabilitate it, a lightweight self-compacting concrete reinforced with fibres (HLACF) has been designed to be used as a filling material, improving the stiffness of the structure. This paper presents a structural analysis of a standard case and the results of an experimental campaign. The concrete showed a density of 1665 kg/m3, a slump flow of 605 mm and a compressive strength of 22.3 MPa, at 28 days. These results are in agreement with the requirements, overcoming common lightweight concrete segregation problems. (Author) 24 refs.

  20. 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.

  1. Study on Sound Absorption Properties of Coconut Coir Fibre Reinforced Composite with Added Recycled Rubber

    Directory of Open Access Journals (Sweden)

    S. Mahzan

    2010-06-01

    Full Text Available Sound pollutions have become worsen and creating concerns for many peoples. Conventionally, expensive sound absorption materials are employed to control noise disturbances. However, recent developments on natural fibres have created interest for researchers especially for acoustics application purposes. This paper investigates the viability of coconut coir added with recycled rubber to be implemented as sound absorption panel. The composite is constructed at prescribed percentages of fillers and polyurethane as resin. The two-microphone method was applied to obtain the acoustic properties of the samples. The samples were also tested for physical properties such as density and porosity, as well as the microstructures. The results demonstrate good acoustics performances and highlight the potential of the coconut coir reinforced with recycled rubber as the sound absorption panel.

  2. Durability of Steel Fibres Reinforcement Concrete Beams in Chloride Environment Combined with Inhibitor

    Directory of Open Access Journals (Sweden)

    AbdelMonem Masmoudi

    2016-01-01

    Full Text Available This paper presented the effect of the combination of an inhibitor and steel fibre reinforced concrete (SFRC for concrete structures in chloride environments. Twelve beams were cast and tested to study their flexural behavior. The morphology of steel surfaces using the inhibitor after observing the scanning electron microscope showed a low layer of corrosion products. The steel surface immersed in the inhibitor free solution was seen to have been subject to chloride ions attacks as shown in this study. The interest to the field of the present study is the relatively higher durability of the performance when using the inhibitor. Crack width and crack spacing for beams under the same load showed that the use of SFRC with the inhibitor for concrete structures in chloride environments must have transferred tension across cracks that led to reducing crack spacing without any chloride ions attack.

  3. The influence of carbon fibre content on the tribological properties of polyarylate based composites materials

    Institute of Scientific and Technical Information of China (English)

    Burya; A.I.; Chigvintseva; O.P

    2001-01-01

    The analysis of scientific-technical literature has shown the prospectiveness of applyinghigh-temperature thermoplastic polymers - among which there are complex aromatic polyesters -as constructive materials. Mixed polyarylates of DV mark based on diphenilolpropane and themixture of iso- and terephtale acid are mentioned to make the most valuable practical interest. Forimproving technological and exploitation properties the authors of the article have suggested toreinforce the polymer linking element with uglen-9 mark. Combination of the composition compo-nents was realized within the rotating electromagnetic field with the help of non-equiaxial ferro-magnetic elements. The study of tribotechnical characteristics (coefficient of friction, intensity oflinear wear, temperature in the contact zone "polymer specimen - counterbody" of elaborated car-bon plastics) has been made at the disc machine of friction. Investigation of exploitation regimes’(specific pressure and slip velocity) influence on the mentioned properties of the initial polymer hasshown that polyarylate can be recommended for work at values of PV criterion not greater than 1.2MPa · m/s. Hardening the exploitation regimes is accompanied by the catastrophic wear of plastic.Reinforcement of polyarylate with carbon fibre is noted to enable significant improvement (to de-crease the coefficient of friction, to increase resistance to wear) of tribotechnical characteristics ofcarbon plastics. The most optimal is the content of carbon fibre in polyarylate in amount of 25mass.%.

  4. Fabrication and oxidation resistance of titanium carbide-coated carbon fibres by reacting titanium hydride with carbon fibres in molten salts

    International Nuclear Information System (INIS)

    Using carbon fibres and titanium hydride as a reactive carbon source and a metal source, respectively, a protective titanium carbide (TiC) coating was formed on carbon fibres in molten salts, composed of LiCl-KCl-KF, at 750-950 oC. The structure and morphology of the TiC coatings were characterised by X-ray diffraction and scanning electron microscopy, respectively. The oxidation resistance of the TiC-coated carbon fibres was measured by thermogravimetric analysis. The results reveal that control of the coating thickness is very important for improvement of the oxidation resistance of TiC-coated carbon fibres. The oxidative weight loss initiation temperature for the TiC-coated carbon fibres increases significantly when an appropriate coating thickness is used. However, thicker coatings lead to a decrease of the carbon fibres' weight loss initiation temperature due to the formation of cracks in the coating. The TiC coating thickness on carbon fibres can be controlled by adjusting the reaction temperature and time of the molten salt synthesis.

  5. Detection of cracks in a reinforced concrete beam using distributed Brillouin fibre sensors

    International Nuclear Information System (INIS)

    This paper presents the results of using distributed Brillouin fibre sensors to detect crack formation in a simply supported reinforced concrete beam subjected to four-point loading. A Brillouin multiple-peak fitting method was used to enhance the spatial and strain resolutions of the measurements. By doing this, the distributed strain profile along the beam was determined with a 5 cm read-out resolution in comparison with the 15 cm spatial resolution of the fibres. The location of the cracks was identified by locating the positions in the strain profile where the strain suddenly changes, by searching for the maximum compressive or tensile peaks in the Brillouin frequency spectrum, as opposed to conventional strain reading, which focuses solely on the maximum Brillouin peak. The amplitude of the Brillouin peak for the suddenly changed strain (crack) was found to be smaller than half of the amplitude of the maximum Brillouin peak at the maximum strain location corresponding to the average strain of the material, which would have been neglected by standard peak or area fitting methods, especially for fine cracks or the initial crack build-up period

  6. The significance of partial discharge in fibre-reinforced insulating materials

    International Nuclear Information System (INIS)

    As a lack of qualification methods for fibre-reinforced insulating materials of GIS was realized and their partial discharge (PD) behavior is still unclear, a test procedure has been created which stresses tube and dusk shaped specimens simultaneously dielectrically and mechanically. Mechanical stress is applied within the admissible limits either fourpoint bending in case of tubes or pressure difference in case of disks at electric AC fields up to 120 kVrms/cm. To prevent surface discharges the specimens are tested in a 600 kPa SF6 atmosphere. For diagnosis a PD system with a sensitivity of 100 fC (femto coulomb) apparent charge has been developed. Even for high-quality vacuum-impregnated materials partial discharge was detected and a clear influence of mechanical stresses was indicated. The obtained PD patterns were systematized and compared to simulations. The interpretation of PD patterns resulted in a pre-breakdown model which reveals the physical failure process taking place in the fibre/matrix interface of the specimens. The model provides suitable criterions for material judgment at least in a qualitative way. Thus the quality of all tested materials was estimated and general suggestions for the improvement of composite insulating materials are given. The described qualification method is able to detect latent defects, in particular also for vacuum-impregnated composites, which was not possible with conventional methods. A recommendation how to proceed for a quantification in terms of life expectancy by accelerated multistress aging tests is given. (author)

  7. Mechanical and thermal characterisation of poly (l-lactide) composites reinforced with hemp fibres

    Science.gov (United States)

    Shakoor, A.; Muhammad, R.; Thomas, N. L.; Silberschmidt, V. V.

    2013-07-01

    Polylactic acid (PLA) is the most promising in the bio-derived polymer's family. But its use can be constrained by its poor mechanical properties, poor thermal stability and processing difficulties. The objective of this research is to investigate and improve mechanical and dynamic thermal properties of PLA by developing PLA composites reinforced with natural fibres (hemp). Composites were prepared by melt blending of PLA with hemp fibres. Their properties were investigated using mechanical and dynamic thermal analysis. The elastic modulus increased significantly - from 4.1 ± 0.74 to 9.32 ± 0.86 (GPA) - when the weight fraction of hemp increased from 0 to 30(wt %). The storage modulus obtained by dynamic mechanical analysis increased from 2.20 to 4.58 (GPA) for the same change in the volume fraction of hemp. FE simulation of tensile testing and DMA were carried out to investigate the effect of strain rate and temperature on the observed properties respectively. The model was developed in the commercially available code MSC Marc mentate. The model validated all experimental results.

  8. Assessing the Environmental Impact of Flax Fibre Reinforced Polymer Composite from a Consequential Life Cycle Assessment Perspective

    Directory of Open Access Journals (Sweden)

    Yelin Deng

    2015-08-01

    Full Text Available The study implements the consequential life cycle assessment (CLCA to provide a market based perspective on how overall environmental impact will change when shifting glass fibres to flax fibres as reinforcements in composite fabrication. With certain assumptions, the marginal flax fibre supply is identified to be a combination of Chinese flax fibre (70% and French flax fibre (30%. Due to inferior cultivars and coal-fired electricity in Chinese flax cultivation, the CLCA study reveals that flax mat-PP has 0.8–2 times higher environmental impact values than the glass mat-PP in most environmental impact categories over the production and end-of-life (EoL phases. For purpose of providing potential trajectories of marginal flax fibre supply, additional scenarios: the “all French fibre”, and “all Chinese fibre” are evaluated formulating the lower and upper boundaries in terms of environmental impact change, respectively. A “the attributional fibre supply mix” scenario is supplied as well. All of these scenarios are useful for policy analysis.

  9. ANALYTIC INVESTIGATIONS OF CARBON FIBER REINFORCED POLYMER STIFFENED CYLINDRICAL SUBMARINE HULL

    Directory of Open Access Journals (Sweden)

    ALICE MATHAI

    2013-07-01

    Full Text Available A submarine is any naval vessel that is capable of propelling itself beneath the water as well as on the water surface. Submersibles are capable of operating for extended period of time underwater and are subjected to heavy hydrostatic pressure. The conventional submarines made up of high strength steel and concrete prevents them from going to greater depth owing to its large dead weight. In the present work, the pressure hull of submarine is considered both in isotropic and composite material. Materials that have high strength to weight ratio include carbon fibre composites. Carbon-fibre reinforced polymer (CFRP is a very strong and light weight fibre reinforced polymer containing carbon fibers on various orientations. It has many applications in aerospace and automotive fields. A parametric study is conducted to find the optimum ply orientation by employing FiniteElement Analysis Software package, ANSYS. Also linear and nonlinear buckling analysis is used to predict the feasibility of CFRP submarine at the deep waters. From the studies conducted regarding the weight reduction, it is estimated that by replacing steel by CFRP results in saving of 67% in the structural weight.

  10. In-process deformation measurements of translucent high speed fibre-reinforced disc rotors

    Science.gov (United States)

    Philipp, Katrin; Filippatos, Angelos; Koukourakis, Nektarios; Kuschmierz, Robert; Leithold, Christoph; Langkamp, Albert; Fischer, Andreas; Czarske, Jürgen

    2015-07-01

    The high stiffness to weight ratio of glass fibre-reinforced polymers (GFRP) makes them an attractive material for rotors e.g. in the aerospace industry. We report on recent developments towards non-contact, in-situ deformation measurements with temporal resolution up to 200 µs and micron measurement uncertainty. We determine the starting point of damage evolution inside the rotor material through radial expansion measurements. This leads to a better understanding of dynamic material behaviour regarding damage evolution and the prediction of damage initiation and propagation. The measurements are conducted using a novel multi-sensor system consisting of four laser Doppler distance (LDD) sensors. The LDD sensor, a two-wavelength Mach-Zehnder interferometer was already successfully applied for dynamic deformation measurements at metallic rotors. While translucency of the GFRP rotor material limits the applicability of most optical measurement techniques due to speckles from both surface and volume of the rotor, the LDD profits from speckles and is not disturbed by backscattered laser light from the rotor volume. The LDD sensor evaluates only signals from the rotor surface. The anisotropic glass fibre-reinforcement results in a rotationally asymmetric dynamic deformation. A novel signal processing algorithm is applied for the combination of the single sensor signals to obtain the shape of the investigated rotors. In conclusion, the applied multi-sensor system allows high temporal resolution dynamic deformation measurements. First investigations regarding damage evolution inside GFRP are presented as an important step towards a fundamental understanding of the material behaviour and the prediction of damage initiation and propagation.

  11. Experimental and numerical thermal analysis of a balcony board with integrated glass fibre reinforced polymer GFRP elements

    Energy Technology Data Exchange (ETDEWEB)

    Ghazi Wakili, K.; Simmler, H.; Frank, T. [Swiss Federal Laboratories for Materials Testing and Research (Empa), Duebendorf (Switzerland)

    2007-07-01

    The thermal behaviour of a balcony board with integrated glass fibre reinforced plastic (GFRP) elements replacing the compression reinforcement rods, is investigated by means of measurement as well as numerical analysis. For this reason a specimen consisting of an externally insulated brick wall and a representative part of a balcony is tested under a steady state temperature gradient of 30 K in a guarded hot box. Additionally to the normative requirements, temperature sensors are placed on critical sites within the construction, prior to the pouring of cement, to help the verification of the numerical analysis carried out simultaneously. Measured and calculated results are compared and some numerical parameter studies are carried out to quantify the advantage of glass fibre reinforced plastic elements over conventional balcony boards from a thermal point of view. (author)

  12. Microwave heating as a means for carbon fibre recovery from polymer composites: a technical feasibility study

    International Nuclear Information System (INIS)

    Carbon fibre composites with an epoxy resin matrix were subjected to microwave-heating experiments in order to volatilise the polymer content and to produce clean fibres for potential reuse in high-grade applications. The composites were processed at 3 kW for 8 s in a multimode microwave applicator. The recovered fibres were characterised by tensile tests and electron microscopy. The results compare favourably with virgin fibre properties

  13. Experimental and numerical studies on the sensitivity of carbon fibre/silicone rubber composite sensors

    International Nuclear Information System (INIS)

    Flexible conductive composite sensors are of great importance for applications in structural monitoring due to their low cost, high durability and excellent compatibility. In this work, carbon fibre/silicone rubber composites were prepared and their sensitivity near the percolation threshold was investigated experimentally and theoretically. Results show that carbon fibre/silicone rubber composites have great mechanical and sensitivity even under high strain conditions. Two models based on the tunnelling effect and general effective medium theory were found to understand the sensitivity of composites with lower and higher fractions of carbon fibre. Moreover, the reversibility of the sensing performance is improved with the increase of carbon fibre addition. (paper)

  14. The reinforcement effect of polyethylene fibre and composite impregnated glass fibre on fracture resistance of endodontically treated teeth: An in vitro study

    Directory of Open Access Journals (Sweden)

    Archana Luthria

    2012-01-01

    Full Text Available Aim: The aim of this study was to evaluate the fracture resistance of endodontically treated maxillary premolars with wide mesio-occluso-distal (MOD cavities restored with either composite resin, or composite resin reinforced with different types of fibres. Materials and Methods: Fifty human maxillary premolars were selected. Five intact teeth served as positive controls. Endodontic therapy was carried out in the remaining forty-five teeth. Standardized MOD cavities were prepared in all the teeth. The teeth were restored with a nanocomposite using an incremental technique. These forty five teeth were randomly divided into three experimental groups (Group A, B and C (n = 15. The teeth in Group A did not undergo any further procedures. The teeth in Group B and C were reinforced with composite impregnated glass fibre and polyethylene fibre, respectively. Fracture resistance was measured in Newtons (N. Results: The positive controls showed the highest mean fracture resistance (811.90 N, followed by Group B (600.49N, Group A (516.96N and Group C (514.64N, respectively. One Way analysis of variance (ANOVA test revealed a statistically significant difference between all the groups (P = 0.001. Post-hoc Tukey test revealed a moderately significant difference (P = 0.034 between Control and Group B, and a strongly significant difference between Control and Group A (P = 0.002, and Control and Group C (P = 0.001. Conclusions: Endodontic therapy and MOD cavity preparation significantly reduced the fracture resistance of endodontically treated maxillary premolars (P = 0.001. No statistically significant difference was found between the experimental groups (Group A, B and C (P > 0.1. However, the fracture resistance of the composite impregnated glass fibre reinforced group was much higher than the others.

  15. Toughening of a Carbon-Fibre Composite Using Electrospun Poly(Hydroxyether of Bisphenol A) Nanofibrous Membranes Through Inverse Phase Separation and Inter-Domain Etherification

    OpenAIRE

    Bronwyn Fox; Thomas Chaffraix; Kevin Magniez

    2011-01-01

    The interlaminar toughening of a carbon fibre reinforced composite by interleaving a thin layer (~20 microns) of poly(hydroxyether of bisphenol A) (phenoxy) nanofibres was explored in this work. Nanofibres, free of defect and averaging several hundred nanometres, were produced by electrospinning directly onto a pre-impregnated carbon fibre material (Toray G83C) at various concentrations between 0.5 wt % and 2 wt %. During curing at 150 °C, phenoxy diffuses through the epoxy resin to form a se...

  16. Recycling solid residues recovered from glass fibre-reinforced composites – A review applied to wind turbine blade materials

    DEFF Research Database (Denmark)

    Beauson, Justine; Lilholt, Hans; Brøndsted, Povl

    2014-01-01

    recovered glass fibre (GF) into new polymer composite. WT blades are mainly made of glass fibre reinforced polymer (GFRP) using thermosetting resins. Shredding this material and recovering GF are possible recycling solutions for WT blade. Based on a detailed literature review, the formulations of new...... face large amount of future wind turbine (WT) blades coming to EoL. Among the EoL solutions available for WT blades, i.e. reuse, remanufacturing, recycling, incineration or disposal, this literature review focuses on recycling and particularly the recycling of shredded composite (SC) materials and...

  17. Enhanced toughness and stable crack propagation in a novel tungsten fibre-reinforced tungsten composite produced by chemical vapour infiltration

    Science.gov (United States)

    Riesch, J.; Höschen, T.; Linsmeier, Ch; Wurster, S.; You, J.-H.

    2014-04-01

    Tungsten is a promising candidate for the plasma-facing components of a future fusion reactor, but its use is strongly restricted by its inherent brittleness. An innovative concept to overcome this problem is tungsten fibre-reinforced tungsten composite. In this paper we present the first mechanical test of such a composite material using a sample containing multiple fibres. The in situ fracture experiment was performed in a scanning electron microscope for close observation of the propagating crack. Stable crack propagation accompanied with rising load bearing capacity is observed. The fracture toughness is estimated using the test results and the surface observation.

  18. Epoxy Enhanced by Recycled Milled Carbon Fibres in Adhesively-Bonded CFRP for Structural Strengthening

    Directory of Open Access Journals (Sweden)

    Chao Wu

    2013-12-01

    Full Text Available This paper investigates the mechanical performance and electrical resistivity of a structural adhesive epoxy enhanced using milled carbon fibre (MCF as well as the bond performance of carbon fibre reinforced polymers (CFRP and steel adhesively bonded joints using the enhanced epoxy. The epoxy was enhanced using such MCFs with different weight ratios of 1.5%, 3% and 5%. Tensile experiments were performed on the original and enhanced epoxy specimens according to ASTM D638. More ductile process failure was found for the epoxy after modification and significant improvements of E-modulus and tensile strength were evidenced when the MCF weight ratio was larger than 1.5%. Scanning electron microscopy (SEM revealed that the failure mechanism of short MCFs pulled out from the epoxy matrix contributed to the enhancement of the mechanical performance of the epoxy. The electrical resistivity of the epoxy with MCF weight ratio of 5% was reduced by at least four orders of magnitude compared to the original epoxy, due to the conductive network formed by MCFs. Steel/CFRP double strap joints (with either CFRP sheets or CFRP laminates were prepared using the enhanced epoxy and then tested in tension, however no obvious increase in joint stiffness or strength was observed.

  19. Non-contact SQUID-NDT method using a ferrite core for carbon-fibre composites

    International Nuclear Information System (INIS)

    Carbon-fibre composites (CFCs), such as carbon-fibre-reinforced plastic (CFRP), are promising composite materials for aerospace structures. However, there is no reliable non-contact NDT method for the detection of deep-lying cracks in thick CFCs at the present time. In this study a non-contact eddy-current-based SQUID-NDT method for thick CFCs was developed. Because CFC is conductively low (electrically), and the target CFC is thick, an induction coil with a U-shaped ferrite core was employed to generate a strong induction field while supplying a low frequency current to the coil. This method was applied to 20 mm thick CFRP specimens with hidden slots at various depths. All signal responses due to the slots located at 5 mm up to 17.5 mm in depth were successfully detected while supplying 150 mA at 300 Hz. The peak amplitude of the response obtained by the method was the same as, or larger than, that of previous results on the same specimens by the current injection method. It shows that the developed method can efficiently induce a large eddy current in the conductively low specimen. It is concluded that this method has the potential to be applicable to the non-contact NDT on very thick CFCs

  20. Gbit/s data transmission on carbon fibres

    International Nuclear Information System (INIS)

    Data transmission at the upgraded Large Hadron Collider experiments, foreseen for mid 2020s, will be in the multi Gbit/s range per connection for the innermost detector layers. This paper reports on first tests on the possible use of carbon cables for electrical data transmission close to the interaction point. Carbon cables have the potential advantage of being light, having a low activation and easy integration into the detector components close to the interaction point. In these tests commercially available carbon fibres were used, in which the filaments had a very thin nickel coating. For these cables data rates beyond 1 Gbit/s over more than 1 m with an error rate of less than 10-12 could be reached. The characteristics of the cables have been measured in terms of S-parameters and could be converted to a SPICE model. Some outlook on potential further improvements is presented

  1. Gbit/s data transmission on carbon fibres

    Science.gov (United States)

    Flick, T.; Glitza, K.-W.; Kappen, G. C.; Mättig, P.; Möller, J.; Sanny, B.

    2016-03-01

    Data transmission at the upgraded Large Hadron Collider experiments, foreseen for mid 2020s, will be in the multi Gbit/s range per connection for the innermost detector layers. This paper reports on first tests on the possible use of carbon cables for electrical data transmission close to the interaction point. Carbon cables have the potential advantage of being light, having a low activation and easy integration into the detector components close to the interaction point. In these tests commercially available carbon fibres were used, in which the filaments had a very thin nickel coating. For these cables data rates beyond 1 Gbit/s over more than 1 m with an error rate of less than 10-12 could be reached. The characteristics of the cables have been measured in terms of S-parameters and could be converted to a SPICE model. Some outlook on potential further improvements is presented.

  2. Chopped basalt fibres: A new perspective in reinforcing poly(lactic acid to produce injection moulded engineering composites from renewable and natural resources

    Directory of Open Access Journals (Sweden)

    P. Tamas

    2013-02-01

    Full Text Available This paper focuses on the reinforcing of Poly(lactic acid with chopped basalt fibres by using silane treated and untreated basalt fibres. Composite materials with 5–10–15–20–30–40 wt% basalt fibre contents were prepared from silane sized basalt fibres using extrusion, and injection moulding, while composites with 5–10–15 wt% basalt fibre contents were also prepared by using untreated basalt fibres as control. The properties of the injection moulded composites were extensively examined by using quasi-static (tensile, three-point bending and dynamic mechanical tests (notched and unnotched Charpy impact tests, dynamic mechanical analysis (DMA, differential scanning calorimetry (DSC, heat deflection temperature (HDT analysis, dimensional stability test, as well as melt flow index (MFI analysis and scanning electron microscopic (SEM observations. It was found that silane treated chopped basalt fibres are much more effective in reinforcing Poly(lactic acid than natural fibres; although basalt fibres are not biodegradable but they are still considered as natural (can be found in nature in the form of volcanic rocks and biologically inert. It is demonstrated in this paper that by using basalt fibre reinforcement, a renewable and natural resource based composite can be produced by injection moulding with excellent mechanical properties suitable even for engineering applications. Finally it was shown that by using adequate drying of the materials, composites with higher mechanical properties can be achieved compared to literature data.

  3. Constitutive law describing the strength degradation kinetics of fibre-reinforced composites subjected to constant amplitude cyclic loading

    Science.gov (United States)

    D'Amore, Alberto; Grassia, Luigi

    2016-02-01

    A two-parameter model based on strength degradation was developed and its predictive reliability was checked on a series of fatigue life and residual strength data available in the literature. The modelling approach explicitly accounts for the maximum cyclic stress, σ_{max}, and the stress ratio, R= σ_{min} /σ_{max}, and requires a limited number of experimental fatigue life data to predict the cycle-by-cycle strength degradation kinetics until the "sudden drop" of strength before catastrophic failure. Different loading conditions were analysed for a large variety of composites, including short-glass-fibre-reinforced polycarbonate, [±45]S glass/epoxy laminates, [±35]_{2S} graphite/epoxy laminates, AS4 carbon/epoxy 3k/E7K8 plain weave fabric with [45/-45/90/45/-45/45/-45/0/45/-45]S layup, and [CSM/fabric/(CSM/UD)2]S glass/polyester laminate. The modelling approach indicates that the fatigue life and the residual strength are related to the statistical distribution of the static strength.

  4. A Review of the Radio Frequency Non-destructive Testing for Carbon-fibre Composites

    Directory of Open Access Journals (Sweden)

    Li Zhen

    2016-04-01

    Full Text Available The purpose of this paper is to review recent research on the applications of existing non-destructive testing (NDT techniques, especially radio frequency (RF NDT, for carbon-fibre reinforced plastics (CFRP composites. Electromagnetic properties of CFRP composites that are associated with RF NDT are discussed first. The anisotropic characteristic of the conductivity and the relationship between the penetration depth and conductivity should be paid much attention. Then, the well-established RF NDT including eddy current technique, microwave technique and RF-based thermography are well categorised into four types (i.e. electromagnetic induction, resonance, RF-based thermography and RF wave propagation and demonstrated in detail. The example of impact damage detection using the induction and resonance methods is given. Some discussions on the development (like industrial-scale automated scanning, three-dimensional imaging, short-range ultra-wideband (UWB imaging and the radio frequency identification technology (RFID-based NDT are presented.

  5. Failure modes of vacuum plasma spray tungsten coating created on carbon fibre composites under thermal loads

    International Nuclear Information System (INIS)

    Vacuum plasma spray tungsten (VPS-W) coating created on a carbon fibre reinforced composite (CFC) was tested under two thermal load schemes in the electron beam facility to examine the operation limits and failure modes. In cyclic ELM-like short transient thermal loads, the VPS-W coating was destroyed sub-layer by sub-layer at 0.33 GW/m2 for 1 ms pulse duration. At longer single pulses, simulating steady-state thermal loads, the coating was destroyed at surface temperatures above 2700 deg. C by melting of the rhenium containing multilayer at the interface between VPS-W and CFC. The operation limits and failure modes of the VPS-W coating in the thermal load schemes are discussed in detail.

  6. Pulse-Width Increase of Reflex Triode Vircator Using the Carbon Fibre Cathode

    Science.gov (United States)

    Liu, Lie; Li, Li-Min; Zhang, Xiao-Ping; Wen, Jian-Chun; Wan, Hong

    2006-04-01

    We present the investigation on the reflex triode virtual cathode oscillator in which performances of carbon-fibre and stainless-steel cathodes are compared with each other. The experimental results and analyses show that surface tracking induces the electron emission of the carbon fibre cathode. There are electron emission phenomena observed not only from the top of the carbon fibre but also from its side surface. Compared with the case of the stainless steel cathode, the plasma expansion velocity for the carbon fibre cathode is slower, and using the carbon fibre cathode can widen the pulse width of output microwave. The output microwave pulse width reaches an increase of about 20%. This mechanism is different from the conventional explosive emission of metal cathodes.

  7. Pulse-width increase of reflex triode vircator using the carbon fibre cathode

    International Nuclear Information System (INIS)

    The authors present the investigation on the reflex triode virtual cathode oscillator in which performances of carbon fibre and stainless-steel cathodes are compared with each other. The experimental results and analyses show that surface tracking induces the electron emission of the carbon fibre cathode. There are electron emission phenomena observed not only from the top of the carbon fibre but also from its side surface. Compared with the case of the stainless steel cathode, the plasma expansion velocity for the carbon fibre cathode is slower, and using the carbon fibre cathode can widen the pulse width of output microwave. The output microwave pulse width reaches an increase of about 20%. This mechanism is different from the conventional explosive emission of metal cathodes. (authors)

  8. Effect of pMDI isocyanate additive on mechanical and thermal properties of Kenaf fibre reinforced thermoplastic polyurethane composites

    Indian Academy of Sciences (India)

    Y A El-Shekeil; S M Sapuan; K Abdan; E S Zainudin; O M Al-Shuja’a

    2012-12-01

    The effect of polymeric methylene diphenyl diisocyanate (pMDI) on mechanical and thermal properties of Kenaf fibre (KF) reinforced thermoplastic polyurethane (TPU) composites was studied. Various percentages viz. 2%, 4% and 6%, were studied. The composites were characterized by using tensile testing, thermogravimetric analysis (TG), differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR). It was noticed that the addition of pMDI 2%, 4%and 6% did not induce a better tensile nor thermal properties.

  9. Effects of Rotation and Gravity Field on Surface Waves in Fibre-Reinforced Thermoelastic Media under Four Theories

    Directory of Open Access Journals (Sweden)

    A. M. Abd-Alla

    2013-01-01

    Full Text Available Estimation is done to investigate the gravitational and rotational parameters effects on surface waves in fibre-reinforced thermoelastic media. The theory of generalized surface waves has been firstly developed and then it has been employed to investigate particular cases of waves, namely, Stoneley waves, Rayleigh waves, and Love waves. The analytical expressions for surface waves velocity and attenuation coefficient are obtained in the physical domain by using the harmonic vibrations and four thermoelastic theories. The wave velocity equations have been obtained in different cases. The numerical results are given for equation of coupled thermoelastic theory (C-T, Lord-Shulman theory (L-S, Green-Lindsay theory (G-L, and the linearized (G-N theory of type II. Comparison was made with the results obtained in the presence and absence of gravity, rotation, and parameters for fibre-reinforced of the material media. The results obtained are displayed by graphs to clear the phenomena physical meaning. The results indicate that the effect of gravity, rotation, relaxation times, and parameters of fibre-reinforced of the material medium is very pronounced.

  10. Mechanical properties and fire retardancy of bidirectional reinforced composite based on biodegradable starch resin and basalt fibres

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available Environmental problems caused by extensive use of polymeric materials arise mainly due to lack of landfill space and depletion of finite natural resources of fossil raw materials, such as petroleum or natural gas. The substitution of synthetic petroleum-based resins with natural biodegradable resins appears to be one appropriate measure to remedy the above-mentioned situation. This study presents the development of a composite that uses environmentally degradable starch-based resin as matrix and basalt fibre plain fabric as reinforcement. Prepreg sheets were manufactured by means of a modified doctor blade system and a hot power press. The sheets were used to manufacture bidirectional-reinforced specimens with fibre volume contents ranging from 33 to 61%. Specimens were tested for tensile and flexural strength, and exhibited values of up to 373 and 122 MPa, respectively. Through application of silane coupling agents to the reinforcement fibres, the flexural composite properties were subsequently improved by as much as 38%. Finally, in order to enhance the fire retardancy and hence the applicability of the composite, fire retardants were applied to the resin, and their effectiveness was tested by means of flame rating (according to UL 94 and thermogravimetric analysis (TGA, respectively.

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

    Science.gov (United States)

    Bru, Thomas; Hellström, Peter; Gutkin, Renaud; Ramantani, Dimitra; Peterson, Göran

    2016-03-01

    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. PMID:26958626

  12. 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.

  13. Analysis of composition and microstructural uniformity of hybrid glass/carbon fibre composites

    DEFF Research Database (Denmark)

    Beauson, Justine; Markussen, Christen Malte; Madsen, Bo

    2013-01-01

    level are investigated. The different levels of compositions in the composites are defined and experimentally determined. The composite volume fractions are determined using an image analysis based procedure. The global fibre volume fractions are determined using a gravimetrical based method. The local......In hybrid fibre composites, the intermixing of the two types of fibres imposes challenges to obtain materials with a well-defined and uniform microstructure. In the present paper, the composition and the microstructural uniformity of hybrid glass/carbon fibre composites mixed at the fibre bundle...... fibre volume fractions are determined using volumetric calculations. A model is presented to predict the interrelation of volume fractions in hybrid fibre composites. The microstructural uniformity of the composites is analysed by the determined variation in composite volume fractions. Two analytical...

  14. Development of a slim window frame made of glass fibre reinforced polyester

    Energy Technology Data Exchange (ETDEWEB)

    Appelfeld, David; Hansen, Christian S.; Svendsen, Svend [Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK-2800 Kgs. Lyngby (Denmark)

    2010-10-15

    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. In order to estimate performances, detailed thermal calculations were performed in four successive steps including solar energy and light transmittance in addition to heat loss and supplemented with a simplified structural calculation of frame load capacity and deflection. Based on these calculations, we 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 of this material are highly competitive in their contribution to the energy savings. A rational product development method was followed, and the process clearly identified the objectives of the investigation and set out the appropriate way to attain them. Using simple rational development methods, a well-defined and effective window was achieved smoothly and quickly, as is illustrated in the case study. (author)

  15. Bone attachment to glass-fibre-reinforced composite implant with porous surface.

    Science.gov (United States)

    Mattila, R H; Laurila, P; Rekola, J; Gunn, J; Lassila, L V J; Mäntylä, T; Aho, A J; Vallittu, P K

    2009-06-01

    A method has recently been developed for producing fibre-reinforced composites (FRC) with porous surfaces, intended for use as load-bearing orthopaedic implants. This study focuses on evaluation of the bone-bonding behaviour of FRC implants. Three types of cylindrical implants, i.e. FRC implants with a porous surface, solid polymethyl methacrylate (PMMA) implants and titanium (Ti) implants, were inserted in a transverse direction into the intercondular trabeculous bone area of distal femurs and proximal tibias of New Zealand White rabbits. Animals were sacrificed at 3, 6 and 12 weeks post operation, and push-out tests (n=5-6 per implant type per time point) were then carried out. At 12 weeks the shear force at the porous FRC-bone interface was significantly higher (283.3+/-55.3N) than the shear force at interfaces of solid PMMA/bone (14.4+/-11.0 N; panalysis (FEA) revealed that porous FRC implants had mechanical properties which could be tailored to smooth the shear stress distribution at the bone-implant interface and reduce the stress-shielding effect. PMID:19268643

  16. Characterising mode I/mode II fatigue delamination growth in unidirectional fibre reinforced polymer laminates

    International Nuclear Information System (INIS)

    Highlights: • Delamination fatigue behaviour of a unidirectional laminate is investigated. • The threshold strain energy release rate is experimentally determined. • Coefficients of Paris law for crack propagation for mode I and mode II were established. - Abstract: In this paper, fatigue life estimation for delamination growth of laminated fibre reinforced polymer (FRP) composite structures in mode I and mode II based on fracture mechanics is presented. The proposed method was applied to delamination of glass/epoxy laminated composite. Both the threshold energy release rate (Gth) and the delamination propagation based on Paris’ law were studied. The double cantilever beam (DCB) specimen for mode I and 3 points End-Notched Flexure (3ENF) specimen for mode II were used for monotonic fracture tests and the resistance GIR and GIIR as a function of delamination length were determined. For DCB tests, the fatigue onset life test was conducted and the threshold energy release rate, GIth, was found for the subcritical region. Constant amplitude, displacement controlled cyclic fatigue test for both modes was conducted and the delamination crack growth rate (da/dN) as a function of maximum cyclic energy release rate GImax and GIImax for DCB and 3ENF specimens were determined, respectively. From curve fitting to the experimental data, the Paris’ law material constants C and m for mode I and mode II were obtained. Finally, the SEM fractography studies of delaminated surfaces of 3ENF static and fatigued specimens have been done and the different features observed on these surfaces were discussed

  17. A composite-appropriate integration method of thick functional components in fibre-reinforced plastics

    Science.gov (United States)

    Filippatos, A.; Höhne, R.; Kliem, M.; Gude, M.

    2016-03-01

    The use of integrated structural health monitoring systems for critical composite parts, such as wind turbine blades, fuselage and wing parts, is an promising approach to guarantee a safe and efficient operational lifetime of such components. Therefore, the integration of thick functional components like sensors, actuators and electronic components is often necessary. An optimal integration of such components should be ensured without material imperfections in the composite structure, i.e. voids and resin rich areas, and failure of the functional components. In this paper, first investigations were undertaken for a basic understanding of the mechanical performance of a fibre reinforced plastic component with integrated functional elements. The influence of different materials and treatment methods for the encapsulation of electronic components was experimentally investigated under static and dynamic loading tests. By means of a parametric finite element model, the effects of an encapsulation and various parameters such as the shape and orientation of the electronic components were examined. Several encapsulation variants were investigated in order to minimise the chance of failure initiations. Based both on experimental and numerical results, a preferred composite integration concept was selected for an electronic board and some first recommendations for an optimal integration were derived.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Roughness Influence On Macro- And Micro-Tribology Of Multi-Layered Hard Coatings On Carbon Fibre Polymer Composite

    Directory of Open Access Journals (Sweden)

    Lackner J.M.

    2015-09-01

    Full Text Available Goal of this work is the investigation of roughness influences on the abrasive wear behaviour of magnetron sputtered multi-layered, low-friction coatings on carbon-fibre reinforced polymers (CFRP. Higher coating roughness at similar CFRP quality was realized by higher deposition rates, leading to increased heat flux to the substrates during deposition. Thermal expansion of the epoxy matrix on the micro scale results in a wavy, wrinkled surface topography. Both in scratch and reciprocal sliding testing against alumina, the friction coefficients are lower for the smooth coatings, but their wear rate is higher due to low-cycle fatigue caused abrasion.

  20. FLOAT - development of new flexible UHPC. Final report. [Ultra High Performance Fibre Reinforced Concrete

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    The current project is a preliminary study intended to clarify the background and give a better basis for an evaluation of the risks and possible rewards of funding a full project with the overall purpose of developing and testing a new concept for wave energy floaters, made of Ultra High Performance Fibre Reinforced Concrete (UHPC), as an enabling technology for the establishment of competitive wave energy production (FLOAT). As an initial step for this preliminary study of FLOAT an investigation has been undertaken in relation to preliminary design of 2 types of floaters, essential properties of UHPFRC - and identification of necessary developments, compilation of existing data from off shore applications and analysis of effect on Cost Of Energy. Preliminary float design and economical considerations - is a theoretical and numerical study including preliminary float designs and cost estimates. It aims at making a first comparison between the different materials options for DEXA and Wave Star floats and giving a first judgement about the suitability of CRC concrete. This is done through a qualitative assessment of pros and cons of different materials for both types of floats and a design study of the Dexa Wave float. It is concluded that the requirements for the Dexa Wave float are so that CRC is not able to compete with conventional concrete for the best and most cost effective solution. The good durability (leading to low maintenance costs), the mechanical properties and the ductility of CRC are not important enough to offset the increased cost for this float. For Wave Star on the other hand, there are significant advantages in using CRC as the only other option in this case is fibre glass, which is a much more expensive product. An investigation was made of methods of optimizing the properties of CRC - customizing them for particular applications in WEC's. The method of optimization has been to change the types of fibres in the mix, and it is demonstrated

  1. Strength Modeling of High-Strength Concrete with Hybrid Fibre Reinforcement

    OpenAIRE

    A. Ravichandran; K. Suguna; P. N. Ragunath

    2009-01-01

    The low tensile strength and limited ductility, the unavoidable deficiency, of concrete can be overcome by the addition of fibres. High strength concrete (HSC) of 60 MPa containing hybrid fibres, combination of steel and polyolefin fibres, at different volume fraction of 0.5, 1.0, 1.5 and 2.0% were compared in terms of compressive, splitting tensile strength and flexural properties with HSC containing no fibres. Test results showed that the fibres when used in hybrid form could result in enha...

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

    OpenAIRE

    Nawaz, A.; Salimullah, K.; Shah, A; Ahmad, S.

    2010-01-01

    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. Tw...

  3. NDE for Characterizing Oxidation Damage in Reinforced Carbon-Carbon

    Science.gov (United States)

    Roth, Don J.; Rauser, Richard W.; Jacobson, nathan S.; Wincheski, Russell A.; Walker, James L.; Cosgriff, Laura A.

    2009-01-01

    In this study, coated reinforced carbon-carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter s thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using NDE methods. These specimens were heat treated in air at 1143 and 1200 C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3 mm. Single-sided NDE methods were used since they might be practical for on-wing inspection, while x-ray micro-computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon-carbon materials. An RCC sample having a naturally-cracked coating and subsequent oxidation damage was also studied with x-ray micro-CT. This effort is a follow-on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating. The results of that study are briefly reviewed in this article as well. Additionally, a short discussion on the future role of simulation to aid in these studies is provided.

  4. The reinforcement and healing of asphalt mastic mixtures by rejuvenator encapsulation in alginate compartmented fibres

    Science.gov (United States)

    Tabaković, A.; Post, W.; Cantero, D.; Copuroglu, O.; Garcia, S. J.; Schlangen, E.

    2016-08-01

    This paper explores the potential use of compartmented alginate fibres as a new method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are employed to locally distribute the rejuvenator and to overcome the problems associated with spherical capsules and hollow fibres. The work presents proof of concept of the encapsulation process which involved embedding the fibres into the asphalt mastic mixture and the survival rate of fibres in the asphalt mixture. To prove the effectiveness of the alginate as a rejuvenator encapsulating material and to demonstrate its ability survive asphalt production process, the fibres containing the rejuvenator were prepared and subjected to thermogravimetric analysis and uniaxial tensile test. The test results demonstrated that fibres have suitable thermal and mechanical strength to survive the asphalt mixing and compaction process. The CT scan of an asphalt mortar mix containing fibres demonstrated that fibres are present in the mix in their full length, undamaged, providing confirmation that the fibres survived the asphalt production process. In order to investigate the fibres physiological properties and ability to release the rejuvenator into cracks in the asphalt mastic, the environmental scanning electron microscope and optical microscope analysis were employed. To prove its success as an asphalt healing system, compartmented alginate fibres containing rejuvenator were embedded in asphalt mastic mix. The three point bend tests were performed on the asphalt mastic test samples and the degree to which the samples began to self-heal in response was measured and quantified. The research findings indicate that alginate fibres present a promising new approach for the development of self-healing asphalt pavement systems.

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

    OpenAIRE

    Thomas Bru; Peter Hellström; Renaud Gutkin; Dimitra Ramantani; Göran Peterson

    2016-01-01

    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...

  6. Application of carbon fiber reinforced carbon composite to nuclear engineering

    International Nuclear Information System (INIS)

    Carbon fiber reinforced carbon matrix composite (C/C composite) is thought to be one of promising structural materials with high temperature resistivity in the nuclear engineering field. In the high temperature gas-cooled reactors with gas outlet temperature maximum around 1000degC, high performance core internal structures, such as control rod sheath, core restraint mechanism, will be expected to achieve by the C/C composite application. Moreover, in the fusion reactors, plasma facing structures having high temperature with high neutron irradiation and particle collision will be expected to achieve by the C/C composite application. In this paper, current research and development studies of the C/C composite application on both reactors are reviewed and vista of the future on the C/C composite application is mentioned. (author)

  7. Electrospun Carbon Nanotube-Reinforced Nanofiber.

    Science.gov (United States)

    Kim, Sung Mm; Hee Kim, Sung; Choi, Myong Soo; Lee, Jun Young

    2016-03-01

    We fabricated multi-walled carbon nanotube (MWNT) reinforced polyurethane (PU) nanofiber (MWNT-PU) web via electrospinning. In order to optimize the electrospinning conditions, we investigated the effects of various parameters including kind of solvent, viscosity of the spinning solution, and flow rate on the spinnability and properties of nanofiber. N,N-dimethylformamide (DMF), tetrahydrofuran (THF) and their mixture with various volume ratio were used as the spinning solvent. Morphology of the nanofiber was studied using scanning electron microscope (SEM) and transmission electron microscope (TEM), confirming successful fabrication of MWNT-PU nanofiber web with uniform dispersion of MWNT in longitudinal direction of the fiber. The MWNT-PU nanofiber web exhibited two times higher tensile strength than PU nanofiber web. We also fabricated electrically conducting MWNT-PU nanofiber web by coating poly(3,4-ehtylenedioxythiophene) (PEDOT) on the surface of MWNT-PU nanofiber web for electromagnetic interference (EMI) shielding application. The electromagnetic interference shielding effectiveness (EMI SE) was quite high as 25 dB in the frequency range from 50 MHz to 10 GHz. PMID:27455732

  8. Microstructure Changes in Isochronally Annealed Alumina Fibre Reinforced Mg-Ag-Nd-Zr Alloy

    Science.gov (United States)

    Kiehn, J.; Smola, B.; Vostrý, P.; Stulíková, I.; Kainer, K. U.

    1997-12-01

    The commercial alloy QE22 (Mg-Ag-;Nd-Zr alloy) was reinforced by 22 vol% -Al2O3 short fibres applying the squeeze cast technology. Precipitation effects were studied in this material after a preceding solution heat treatment by isochronal annealing up to 300 °C by means of electrical resistivity, hardness and reversible stress relaxation measurements. The annealing response of the properties was compared to the annealing response of the unreinforced matrix alloy. The microstructure changes were studied in detail by transmission electron microscopy. A sharp drop of resistivity between 180 and 280 °C was found on normalised resistivity annealing curves of both reinforced and unreinforced specimens due to the redistribution of solutes. In composites the fibres act as nucleation centres in the precipitation process promoting e.g. precipitation of Al2Nd or Ag compounds. The Al content in the matrix is enhanced due to the decomposition of the preform binder. The evolution of the particle population inside the grains involves the formation of new Al2Nd-like cubic particles between 120 and 180 °C. Above 180 °C these particles are continuously substituted by hexagonal -phase and/or tetragonal Mg12Nd particles. This process finishes at 300 °C by the transformation of all new particles to semicoherent Mg12Nd precipitates. The precipitation process in grain interiors of the unreinforced alloy is different involving only change of the morphological features of tetragonal semicoherent Mg12Nd particles existing in the alloy already in the initial state after solution heat treatment. Die kommerzielle Legierung QE22 (Mg-Ag-Nd-Zr) wurde im Preßgießverfahren mit 22 Vol.-% δ-Al2O3 Kurzfasern verstärkt. Die Untersuchung des Ausscheidungsverhaltens während isochroner Wärmebehandlungen bis 300 °C nach vorangegangenem Lösungsglühen erfolgte über die Bestimmung der Änderung des elektrischen Widerstandes, der Härte und der reversiblen Spannungsrelaxation. Die Auswirkung der

  9. Laser-generated ultrasound with optical fibres using functionalised carbon nanotube composite coatings

    Science.gov (United States)

    Colchester, Richard J.; Mosse, Charles A.; Bhachu, Davinder S.; Bear, Joseph C.; Carmalt, Claire J.; Parkin, Ivan P.; Treeby, Bradley E.; Papakonstantinou, Ioannis; Desjardins, Adrien E.

    2014-04-01

    Optical ultrasound transducers were created by coating optical fibres with a composite of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS). Dissolution of CNTs in PDMS to create the composite was facilitated by functionalisation with oleylamine. Composite surfaces were applied to optical fibres using dip coating. Under pulsed laser excitation, ultrasound pressures of 3.6 MPa and 4.5 MPa at the coated end faces were achieved with optical fibre core diameters of 105 and 200 μm, respectively. The results indicate that CNT-PDMS composite coatings on optical fibres could be viable alternatives to electrical ultrasound transducers in miniature ultrasound imaging probes.

  10. Deformation mechanisms of carbon nanotube fibres under tensile loading by in situ Raman spectroscopy analysis

    International Nuclear Information System (INIS)

    Deformation mechanisms of carbon nanotube (CNT) fibres under tensile loading are studied by means of in situ Raman spectroscopy to detect the CNT deformation and stress distributions in the fibres. The G' band in the Raman spectrum responds distinctly to the tensile stress in Raman shift, width and intensity. The G' band changes with the tensile deformation of the fibre at different stages, namely elastic deformation, strengthening and damage-fracture. It is deduced that the individual CNTs only deform elastically without obvious damage or bond breaking. The yield and fracture of fibres can be due to the slippage among the CNTs.

  11. Stress analysis of lap joints involving natural fibre reinforced interface layers

    OpenAIRE

    J.M. FERREIRA; Silva, H.; J.D. Costa; Richardson, M.

    2005-01-01

    This paper is concerned with a fatigue study of composite adhesive lap joints. The tests were carried out on specimen joints manufactured using different stacking sequences: solely bi-directional woven E-glass fibres and polypropylene composites; and hybrid stacked composites. The main objective of the work was to improve the fatigue strength using hybrid fibre composites with a polypropylene/hemp natural fibre layer adjacent to the bond interface which was expected to produce more uniform st...

  12. Friction and wear behavior of carbon fiber reinforced brake materials

    Institute of Scientific and Technical Information of China (English)

    Du-qing CHENG; Xue-tao WANG; Jian ZHU; Dong-bua QIU; Xiu-wei CHENG; Qing-feng GUAN

    2009-01-01

    A new composite brake material was fabri-cated with metallic powders, barium sulphate and modified phenolic resin as the matrix and carbon fiber as the reinforced material. The friction, wear and fade character-istics of this composite were determined using a D-MS friction material testing machine. The surface structure of carbon fiber reinforced friction materials was analyzed by scanning electronic microscopy (SEM). Glass fiber-reinforced and asbestos fiber-reinforced composites with the same matrix were also fabricated for comparison. The carbon fiber-reinforced friction materials (CFRFM) shows lower wear rate than those of glass fiber- and asbestos fiber-reinforced composites in the temperature range of 100℃-300℃. It is interesting that the frictional coefficient of the carbon fiber-reinforced friction materials increases as frictional temperature increases from 100℃ to 300℃, while the frictional coefficients of the other two composites decrease during the increasing temperatures. Based on the SEM observation, the wear mechanism of CFRFM at low temperatures included fiber thinning and pull-out. At high temperature, the phenolic matrix was degraded and more pull-out enhanced fiber was demonstrated. The properties of carbon fiber may be the main reason that the CFRFM possess excellent tribological performances.

  13. Static and fatigue behaviour of glass-fibre-reinforced polypropylene composites

    OpenAIRE

    Ferreira, J. A. M.; Costa, J. D. M.; Reis, P. N. B.

    1999-01-01

    This paper is concerned with fatigue of polypropylene/glass-fibre thermoplastic composites produced from a bi-directional woven cloth mixture of E glass fibres and polypropylene fibres. The latter becomes the matrix after the application of heat and pressure. This composite was manufactured with a fibre volume fraction Vf of 0.338. The effect of layer design on the static and fatigue performance was investigated. The S-N curves, the rise in the temperature of the specimens during the tests an...

  14. A facile method for processing lignin reinforced chitosan biopolymer microfibres: optimising the fibre mechanical properties through lignin type and concentration

    Science.gov (United States)

    Wang, K.; Loo, L. S.; Goh, K. L.

    2016-03-01

    A chitosan biopolymer microfibre—reinforced by lignin—has been processed by a wet-spinning method. To optimise the fibre mechanical and structural properties two types of lignin, with molecular weights 28 000 g mol-1 and 60 000 g mol-1, were examined and the chitosan fibre was blended with the respective lignin type at 1, 3, 5, 7 and 8 wt% lignin concentrations. The main effects of lignin type and concentration, as well as the interaction between the two parameters, on the fibre tensile stiffness, extensibility, strength and toughness were evaluated using the two-factor analysis of variance. Significant variations in the respective mechanical properties were observed with varying lignin concentrations (P lignin concentration. Except for extensibility, significant variations in the strength and toughness were observed with respect to lignin type (P lignin type and concentration. These results were related to the dispersion of lignin in the fibre and the nature of the bonds between lignin and chitosan, based on findings from scanning electron microscopy and Fourier transform infrared spectroscopy. This new method for the fabrication of chitosan biopolymer microfibre is inexpensive and versatile and could lend itself to the production of high performance biocomposite structures.

  15. Experimental Study on Electric Properties of Carbon Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the phenomenon that the physical properties have a great effect on the electric capability of carbon fiber reinforced concrete, the author researched the relationship between DC resistance of carbon fiber reinforced concrete and curing age using the two-probe method. Then the effect of insulative area,location and quantity on DC resistance of carbon fiber reinforced concrete was investigated at different curing age with analysis of hydration. The results suggest that DC resistance increases greatly with its curing age, which illustrates the relationship like Gaussian curve. In every curing ages the electric capability of carbon fiber reinforced concrete weakenes with the increase of insulative area. In same curing ages, section and insulative area, the more the quantity of insulation, the stronger the conductibility. The insulative location in optimal position can only result in optimal conductibility.

  16. Reduction of preferential erosion of carbon fibre composites under intense transient heat pulses

    International Nuclear Information System (INIS)

    Two fusion-relevant carbon fibre composites (CFCs), NB31 (3D) and DMS704 (2D), have been thermally exposed in five different orientations to simulate transient events (disruptions and ELMs). In these experiments with intense transient heat pulses in the electron beam JUDITH and the ion beam facility RHEPP-1, CFCs showed a preferential erosion of the fibre bundles aligned in the surface-plane. This phenomenon also occurred when these fibre bundles were the ones with the highest thermal conductivity. First results show that reduction of the number of fibres aligned parallel to the surface-plane strongly contributes to limiting the preferential erosion by fibre segment ejection (brittle destruction) in CFCs. Strong mechanical attachment is essential to avoid fibre segment ejection during disruption. The selection of an optimum material orientation of the available CFCs is of relevant importance and will be further investigated

  17. Improved osteoblast viability in the presence of smaller nanometre dimensioned carbon fibres

    Science.gov (United States)

    Price, Rachel L.; Haberstroh, Karen M.; Webster, Thomas J.

    2004-08-01

    Carbon nanofibres have been proposed as a possible new orthopaedic/dental implant material due to their unique mechanical, electrical, and cytocompatibility properties. Specifically, these fibres have dimensions (diameters ranging between 60 and 200 nm and aspect ratios of about 500) similar to hydroxyapatite crystals and collagen fibres found in bone. More importantly, previous in vitro studies have provided evidence that nanophase ({\\le } 100 nm diameter) carbon fibres enhance osteoblast (the bone-producing cell) function over conventional (>100 nm diameter) carbon fibres and current orthopaedic implant materials such as titanium, Ti6Al4V, and CoCrMo. However, articulating components of orthopaedic implant materials may generate harmful wear debris. To determine, for the first time, the influence of carbon nanofibre wear debris on osteoblast viability, direct contact toxicity studies were performed in the present in vitro study. Not surprisingly, the results from direct-contact toxicity studies over a 24 h time period provided evidence of time- and concentration-dependent cell viability decreases when exposed to carbon nanofibres. Most importantly, the results from this study provided the first evidence that nanophase carbon fibres were less detrimental to osteoblast viability compared to larger diameter conventional carbon fibres. For this reason, this in vitro study provided continuing evidence of the promise of nanophase materials (particularly, carbon nanofibres) in improving orthopaedic implant efficiency.

  18. Radiation processing for PTFE composite reinforced with carbon fiber

    International Nuclear Information System (INIS)

    The present work is an attempt to evaluate the performance of crosslinked PTFE as a polymer matrix for carbon fiber-reinforced composite materials. The carbon fiber-reinforced PTFE pre-composite, which is laminated with PTFE fine powder, is crosslinked by electron beam irradiation. Mechanical and frictional properties of the crosslinked PTFE composite obtained are higher than those of PTFE resin. The crosslinked PTFE composite with high mechanical and radiation resistant performance is obtained by radiation crosslinking process

  19. Production of continuous intermingled CF/GF hybrid composite via fibre tow spreading technology

    OpenAIRE

    Diao, H.; Bismarck, A.; Robinson, P.; Wisnom, M. R.

    2014-01-01

    An air-assisted fibre tow spreader was used to produce continuous commingled glass and carbon fibre tows. Hybrid carbon and glass fibre (CF/GF) reinforced epoxy composites were manufactured from these commingled fibre tows by resin film infusion. The degree of hybridisation of the hybrid CF/GF tow was defined and characterised. Compared with the corresponding continuous CF/epoxy composite, the hybrid composite with a degree of hybridisation of 32.45% exhibits a more gradual tensile failure. T...

  20. Carbon fiber reinforced thermoplastic composites for future automotive applications

    Science.gov (United States)

    Friedrich, K.

    2016-05-01

    After a brief introduction to polymer composite properties and markets, the state of the art activities in the field of manufacturing of advanced composites for automotive applications are elucidated. These include (a) long fiber reinforced thermoplastics (LFT) for secondary automotive components, and (b) continuous carbon fiber reinforced thermosetting composites for car body applications. It is followed by future possibilities of carbon fiber reinforced thermoplastic composites for e.g. (i) crash elements, (ii) racing car seats, and (iii) production and recycling of automotive fenders.

  1. Durability and inflammogenic impact of carbon nanotubes compared with asbestos fibres

    Directory of Open Access Journals (Sweden)

    Clark Steve

    2011-05-01

    Full Text Available Abstract Background It has been suggested that carbon nanotubes might conform to the fibre pathogenicity paradigm that explains the toxicities of asbestos and other fibres on a continuum based on length, aspect ratio and biopersistence. Some types of carbon nanotubes satisfy the first two aspects of the fibre paradigm but only recently has their biopersistence begun to be investigated. Biopersistence is complex and requires in vivo testing and analysis. However durability, the chemical mimicking of the process of fibre dissolution using in vitro treatment, is closely related to biopersistence and more readily determined. Here, we describe an experimental process to determine the durability of four types of carbon nanotubes in simulated biological fluid (Gambles solution, and their subsequent pathogenicity in vivo using a mouse model sensitive to inflammogenic effects of fibres. The in vitro and in vivo results were compared with well-characterised glass wool and asbestos fibre controls. Results After incubation for up to 24 weeks in Gambles solution, our control fibres were recovered at percentages consistent with their known in vitro durabilities and/or in vivo persistence, and three out of the four types of carbon nanotubes tested (single-walled (CNTSW and multi-walled (CNTTANG2, CNTSPIN showed no, or minimal, loss of mass or change in fibre length or morphology when examined by electron microscopy. However, the fourth type [multi-walled (CNTLONG1] lost 30% of its original mass within the first three weeks of incubation, after which there was no further loss. Electron microscopy of CNTLONG1 samples incubated for 10 weeks confirmed that the proportion of long fibres had decreased compared to samples briefly exposed to the Gambles solution. This loss of mass and fibre shortening was accompanied by a loss of pathogenicity when injected into the peritoneal cavities of C57Bl/6 mice compared to fibres incubated briefly. CNTSW did not elicit an

  2. Computertomographic investigation of steel fibre reinforced sprayed concrete using multi-dimensional transfer functions [Computertomografische Untersuchung von Stahlfaserspritzbeton mit mehrdimensionalen Transferfunktionen

    KAUST Repository

    Pittino, Gerhard

    2011-06-01

    The composite material steel fibre reinforced concrete or steel fibre reinforced sprayed concrete (SFRS) is widely used in geotechnics. For the modelling of the mechanical behaviour the knowledge of the distribution and orientation of the fibres in the concrete is of particular importance. For a bachelor thesis the steel fibres in drill cores were investigated by computed tomography (CT) at the Austrian Foundry Research Institute (ÖGI). The orientation of each fibre was calculated using a STL-interface and further software tools. The results were statistically evaluated and graphically represented using Schmidt\\'s net. This time consuming (expensive) method was automated by a post-processing of VRVis. With that tool the steel fibres in the sample can be explored, classified and visually examined in real-time regarding their orientation in two angles. Different possibilities of statistical evaluation can be implemented. A real-time direction sphere histogram (DSH), comparable to Schmidt\\'s net in 3D allows the user to recognise the distribution of orientations of the selected fibres at a glance. The colour-coding of the different orientations is also used for the 3D-volume-view of the fibres, to easily identify the spatial distribution of orientations in the SFRS sample. © 2011 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

  3. Correlation between mechanical and dielectric properties of Alfa/Wool/Polymeric hybrid fibres reinforced polyester composites

    International Nuclear Information System (INIS)

    Dielectric measurements and tensile testing of polyester/natural fibres (Alfa/wool) and thermo binder fibres (Pe/Pet) composites were investigated in order to study the adhesion of the fibres in the polyester matrix. Two composites #1 and #2 having 17:1:2 and 17:2:1 as a relative fraction of alfa/wool and thermo binder (Pe/Pet), respectively, have been characterized in this study. The obtained results revealed that the fibres adhesion in the matrix was better in the composite #1 than in the composite #2. Indeed, the analysis of the interfacial or Maxwell-Wagner-Sillars (MWS) polarization intensity, using the Havriliak–Negami model, has shown a lower intensity and the tensile testing exhibited a higher Young modulus in the composite #1. So the thermo binder fibres improve this adhesion

  4. Microstructural Assessment of Fibre Damage after Tensile and Shear Creep Deformation of a Short Fibre Reinforced Aluminium Alloy with a Fibre Volume Fraction of 8

    Czech Academy of Sciences Publication Activity Database

    Yawny, A.; Kausträter, G.; Válek, Robert; Schürhoff, J.; Skrotzki, B.; Eggeler, G.; Stöckhert, B.

    London : The Institute of Materials, 2001 - (Parker, J.), s. 219-228 ISBN 1-86125-144-0. [International Conference on Creep and Fracture of Engineering Materials and Structures /9./. Swansea (GB), 01.04.2001-04.04.2001] Grant ostatní: -(DE) SFB526-D4 Institutional research plan: CEZ:AV0Z2041904 Keywords : creep * composites * fibres Subject RIV: JG - Metallurgy

  5. Electrodeposition of Nickel onto 12K Carbon Fibre Tow in a Continuous Manner

    OpenAIRE

    Pierozynski, Boguslaw

    2012-01-01

    Nickel-coated carbon fibre (NiCCF) is an important composite material, which finds nu- merous engineering applications, primarily within: computer, telecommunication, automotive and military industries. In general, NiCCF can be produced by one of the three methods, namely: chemical vapour deposition (CVD), electroless, and electrochemical (galvanic) deposition of Ni on a carbon fibre tow material. The present paper reports a study of the process of nickel electrodeposition (at ultrathin layer...

  6. Pseudo-ductility in intermingled carbon/glass hybrid composites with highly aligned discontinuous fibres

    OpenAIRE

    Yu, Hana; Longana, Marco L; Jalalvand, Meisam; WISNOM, Michael R.; Potter, Kevin D

    2015-01-01

    The aim of this research is to manufacture intermingled hybrid composites using aligned discontinuous fibres to achieve pseudo-ductility. Hybrid composites, made with different types of fibres that provide a balanced suite of modulus, strength and ductility, allow avoiding catastrophic failure that is a key limitation of composites. Two different material combinations of high strength carbon/E-glass and high modulus carbon/E-glass were selected. Several highly aligned and well dispersed short...

  7. Water-cooled non-thermal gliding arc for adhesion improvement of glass-fibre-reinforced polyester

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom;

    2013-01-01

    A non-equilibrium quenched plasma is prepared using a gliding-arc discharge generated between diverging electrodes and extended by a gas flow. It can be operated at atmospheric pressure and applied to plasma surface treatment to improve adhesion properties of material surfaces. In this work, glass......-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding-arc discharge with air flow to improve adhesion with a vinylester adhesive. The electrodes were water-cooled so as to operate the gliding arc continually. The treatment improved wettability and increased the density of oxygen...

  8. Effect of carbon fibre on properties of TiB2/C composite cathode coating for aluminum electrolysis

    Institute of Scientific and Technical Information of China (English)

    LI Jie; L(U) Xiao-jun; LAI Yan-qing; LI Qing-yu; TIAN Zhong-liang; FANG Zhao

    2008-01-01

    The tensile strength, compressive strength and electrical resistivity of TiB2/C composite cathode coating were measured with a hydraulic pressure universal test machine and an electrical resistivity test device, and the effects of carbon fibre content and carbon fibre length on tensile strength, compressive strength and electrical resistivity were investigated. The results show that the tensile strength of coating increases at the beginning and then reduces with the increase of carbon fibre content when the carbon fibre (length of 3 mm) content ranges from 0 to 4.0%; at the carbon fibre content of 1.5%, the tensile strength of coating reaches the maximum, 25.6 MPa. For the coating with carbon fibre content of 1.5%, the carbon fibre length has a great influence on tensile strength and compressive strength of coating; when the carbon fibre length is 6 mm, the tensile strength and compressive strength of coating reach the maximum, 27.6 MPa and 39.2 MPa, respectively. The electrical resistivity of coating reduces with the rise of temperature and the length of carbon fibre, and the influence of carbon fibre length on electrical resistivity of coating at low temperature (30-200℃) is more obvious than that at high temperature (960℃).

  9. Cutting and drilling of carbon fiber reinforced plastics (CFRP) by 70W short pulse nanosecond laser

    Science.gov (United States)

    Jaeschke, Peter; Stolberg, Klaus; Bastick, Stefan; Ziolkowski, Ewa; Roehner, Markus; Suttmann, Oliver; Overmeyer, Ludger

    2014-02-01

    Continuous carbon fibre reinforced plastics (CFRP) are recognized as having a significant lightweight construction potential for a wide variety of industrial applications. However, a today`s barrier for a comprehensive dissemination of CFRP structures is the lack of economic, quick and reliable manufacture processes, e.g. the cutting and drilling steps. In this paper, the capability of using pulsed disk lasers in CFRP machining is discussed. In CFRP processing with NIR lasers, carbon fibers show excellent optical absorption and heat dissipation, contrary to the plastics matrix. Therefore heat dissipation away from the laser focus into the material is driven by heat conduction of the fibres. The matrix is heated indirectly by heat transfer from the fibres. To cut CFRP, it is required to reach the melting temperature for thermoplastic matrix materials or the disintegration temperature for thermoset systems as well as the sublimation temperature of the reinforcing fibers simultaneously. One solution for this problem is to use short pulse nanosecond lasers. We have investigated CFRP cutting and drilling with such a laser (max. 7 mJ @ 10 kHz, 30 ns). This laser offers the opportunity of wide range parameter tuning for systematic process optimization. By applying drilling and cutting operations based on galvanometer scanning techniques in multi-cycle mode, excellent surface and edge characteristics in terms of delamination-free and intact fiber-matrix interface were achieved. The results indicate that nanosecond disk laser machining could consequently be a suitable tool for the automotive and aircraft industry for cutting and drilling steps.

  10. Lightweight self-compacting concrete reinforced with fibres for slab rehabilitation

    Directory of Open Access Journals (Sweden)

    Klein, N. S.

    2011-06-01

    Full Text Available The slabs of some buildings in Barcelona are formed by unidirectional beams, with a ceramic arch in between, which are filled with broken pottery or construction waste. These structures often present problems such as displacement of the tiles arranged over it due to the lack of stiffness of the filling material. This supposes a risk to the user and could also cause durability problems. In order to rehabilitate it, a lightweight self-compacting concrete reinforced with fibres (HLACF has been designed to be used as a filling material, improving the stiffness of the structure. This paper presents a structural analysis of a standard case and the results of an experimental campaign. The concrete showed a density of 1665 kg/m3, a slump flow of 605 mm and a compressive strength of 22.3 MPa, at 28 days. These results are in agreement with the requirements, overcoming common lightweight concrete segregation problems.

    Los forjados de ciertos edificios del ensanche de Barcelona, formados por viguetas unidireccionales con un revoltón de cerámica entre ellas y un relleno posterior (material cerámico y residuos de construcción, suelen presentar problemas de movimientos y despegues de las baldosas situadas en la parte superior, con el consiguiente riesgo para el usuario, aparte de los problemas de durabilidad asociados. Para rehabilitar esas estructuras se ha diseñado un hormigón ligero autocompactante con fibras (HLACF, como relleno de modo que mejore la rigidez a la estructura. El artículo presenta el análisis estructural de una solución tipo así como los resultados de una campaña experimental realizada. Como resultado se obtiene un hormigón de densidad de 1.665 kg/m3, escurrimiento de 605 mm y resistencia a compresión de 22,3 MPa, a los 28 días, que cumple con los requisitos y significa superar problemas de segregación previsibles para este tipo de hormigones.

  11. Electroless plating and magnetic properties of Co–Zn–P coating on short carbon fibres

    Indian Academy of Sciences (India)

    Xinghua Su; Chengwen Qiang

    2012-12-01

    A layer of Co–Zn–P alloys was coated on short carbon fibre (CFs) surfaces using electroless plating method. The influence of the concentration of Co2+ and Zn2+ and reaction time on the plating rate were measured by comparing the relative mass gain rate of Co–Zn–P-coated fibres with uncoated carbon fibres prepared under different conditions. The materials characterizations were analysed by field emission scanning electron microscopy, X-ray diffraction and energy dispersive spectroscope. The magnetic properties of Co–Zn–P/CFs composites prepared in different Zn2+ concentration baths were measured by the vibrating sample magnetometer. The best processing parameters of electroless plating of Co–Zn–P coating on short carbon fibres were obtained.

  12. PROBABILITY MODEL FOR CARBONIZATION OF REINFORCED CONCRETE STRUCTURES

    Directory of Open Access Journals (Sweden)

    S. Leonovich

    2014-10-01

    Full Text Available The paper describes a methodology for calculation of concrete carbonization in respect of reinforced concrete structures used under conditions of the Republic of Belarus. The equation of concrete carbonization rate is presented in the probabilistic form. Such approach makes it possible to predict the service life as new structures at the design stage so the service life of the applied structures.

  13. The carbon footprint of reinforced concrete

    OpenAIRE

    Purnell, P

    2013-01-01

    As legislation forces significant reductions in the operational carbon dioxide emissions of the built environment, increasing attention is focused on the embodied carbon of structural materials. As the most prevalent structural material, the embodied carbon of concrete is of paramount interest. Previous direct or indirect analyses of embodied carbon in concrete have treated it either as an elemental material with a value of single embodied carbon, or calculated embodied carbon for a limited r...

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

    International Nuclear Information System (INIS)

    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.

  15. Effect of curing temperature on flexural properties of silica-based geopolymer-carbon reinforced composite

    Directory of Open Access Journals (Sweden)

    D.H. Tran

    2009-12-01

    Full Text Available Purpose: The aim of this paper is to find out the curing temperature at which we can achieve the best mechanical properties and adhesion between silica-based geopolymer matrix (Q1 and carbon HTS 5631 1600tex 24K fibre.Design/methodology/approach: The carbon fibre was impregnated with silica-based geopolymer by means of home-made “impregnation machine”. This equipment was designed based on simulating the real pultrusion or filament winding technique. Composite samples were made manually in silicon mould and cured under hot vacuum bagging technique at different temperatures. Flexural properties were determined under three-point bending mode in accordance with British Standard BS EN ISO 14125:1998. The sections perpendicular to fibres and surfaces of the composites were analysed by means of scanning electron microscope (SEM to estimate the adhesion between geopolymer matrices and fibre reinforcement.Findings: Relatively wide range of curing temperature from 70oC to 100oC at which we can obtain high flexural properties, maximal values of flexural strength 570 MPa, flexural modulus 65 GPa and relative deformation of composite was 0.98% when the composite was cured and dried at 75oC. Adhesion of the geopolymer matrix to carbon fibre was very good and hardly to determine the differences by SEM image observation within the range of optimal curing temperature.Research limitations/implications: The curing time was too long to provide the geopolymerization process before it had been completed, this factor caused that it should be carried out in the future and we may use liquid absorption to determine how many cavities are in the composites.Practical implications: The research presents original information on the influence of different curing temperatures on mechanical properties and micro-structure of silica-based geopolymer matrix – carbon composite. The results are useful for further investigations.Originality/value: Determining the optimal curing

  16. UNIFORMITY ASSESSMENT OF CARBON FIBRES DISPERSION IN CEMENT PASTE BY IMPEDANCE MEASUREMENTS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    An alternating current was applied to measure the impedance of a hardened cement paste with various contents of carbon fibres.When the free water content in the hardened cement paste is 90%-98%,and the measuring frequency 500Hz,an approximate linear relationship was found between fibre content and impedance of the composite.Based on this relationship,a new attempt was made to evaluate the dispersion uniformity of carbon fibres in cement paste by impedance measurement.The standard deviation S and the coefficient of vriation S/(X-)i of impedance of the fibre-cement specimens randomly taken locating in different points were used as main parameters for the uniformity assessment.As a case,four different mixing processes were designed for dispersing carbon fibres into the cement paste.The results demonstrate that the relative longer mixing time increases the dispersion uniformity of carbon fibres in cement paste,and the addition of the water reducer dramatically improves the uniformity due to the change of the fluidity of the paste.The ground fly ash can increase the uniformity to a certain extent.

  17. Preparation and properties of unidirectional boron nitride fibre reinforced boron nitride matrix composites via precursor infiltration and pyrolysis route

    International Nuclear Information System (INIS)

    Highlights: → BN fibres degrade little when exposed at elevated temperatures. → Precursor infiltration and pyrolysis route is useful to prepare BNf/BN composites. → Few reports have related to the preparation and properties of BNf/BN composites. → BNf/BN composites have desirable high-temperature mechanical properties. → BNf/BN composites have excellent dielectric properties at 2-18 GHz. - Abstract: The unidirectional boron nitride fibre reinforced boron nitride matrix (BNf/BN) composites were prepared via the precursor infiltration and pyrolysis (PIP) route, and the structure, composition, mechanical and dielectric properties were studied. The composites have a high content and fine crystallinity of BN. The density is 1.60 g cm-3 with a low open porosity of 4.66%. The composites display good mechanical properties with the average flexural strength, elastic modulus and fracture toughness being 53.8 MPa, 20.8 GPa and 6.88 MPa m1/2, respectively. Lots of long fibres pull-out from the fracture surface, suggesting a good fibre/matrix interface. As temperature increases, both of the flexural strength and elastic modulus exhibit a decreasing trend, with the lowest values being 36.2 MPa and 8.6 GPa at 1000 deg. C, respectively. The desirable residual ratios of the flexural strength and elastic modulus at 1000 deg. C are 67.3% and 41.3%, respectively. The composites have excellent dielectric properties, with the average dielectric constant and loss tangent being 3.07 and 0.0044 at 2-18 GHz, respectively.

  18. Reinforcing Effects of Carbon Black on Asphalt Binder for Pavement

    OpenAIRE

    Yamaguchi, Katsuyuki; Sasaki, Iwao; Nishizaki, Itaru; Meiarashi, Seishi; Moriyoshi, Akihiro

    2005-01-01

    Carbon black, used as a reinforcing filler for rubber materials, was evaluated for asphalt binders in pavements. Carbon black added to straight asphalt within 20 wt% caused an increase in the elastic modulus and a decrease in the viscosity of the asphalt, especially at temperatures higher than room temperature. Addition of carbon black raised the maximum service temperature of asphalt in the category of the binder performance grade according to the SHRP (Strategic Highway Research Program) sp...

  19. High Power Q-Switched Thulium Doped Fibre Laser using Carbon Nanotube Polymer Composite Saturable Absorber.

    Science.gov (United States)

    Chernysheva, Maria; Mou, Chengbo; Arif, Raz; AlAraimi, Mohammed; Rümmeli, Mark; Turitsyn, Sergei; Rozhin, Aleksey

    2016-01-01

    We have proposed and demonstrated a Q-switched Thulium doped fibre laser (TDFL) with a 'Yin-Yang' all-fibre cavity scheme based on a combination of nonlinear optical loop mirror (NOLM) and nonlinear amplified loop mirror (NALM). Unidirectional lasing operation has been achieved without any intracavity isolator. By using a carbon nanotube polymer composite based saturable absorber (SA), we demonstrated the laser output power of ~197 mW and pulse energy of 1.7 μJ. To the best of our knowledge, this is the highest output power from a nanotube polymer composite SA based Q-switched Thulium doped fibre laser. PMID:27063511

  20. High Power Q-Switched Thulium Doped Fibre Laser using Carbon Nanotube Polymer Composite Saturable Absorber

    Science.gov (United States)

    Chernysheva, Maria; Mou, Chengbo; Arif, Raz; Alaraimi, Mohammed; Rümmeli, Mark; Turitsyn, Sergei; Rozhin, Aleksey

    2016-04-01

    We have proposed and demonstrated a Q-switched Thulium doped fibre laser (TDFL) with a ‘Yin-Yang’ all-fibre cavity scheme based on a combination of nonlinear optical loop mirror (NOLM) and nonlinear amplified loop mirror (NALM). Unidirectional lasing operation has been achieved without any intracavity isolator. By using a carbon nanotube polymer composite based saturable absorber (SA), we demonstrated the laser output power of ~197 mW and pulse energy of 1.7 μJ. To the best of our knowledge, this is the highest output power from a nanotube polymer composite SA based Q-switched Thulium doped fibre laser.

  1. Recycling of Reinforced Plastics

    Science.gov (United States)

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  2. Tensile and Flexural Properties of Aramide/Glass/Onion Fibre Reinforced Epoxy Composites

    OpenAIRE

    G.Meenambika Bai,

    2014-01-01

    Fiber-reinforced Epoxy Composites have played a dominant role for a long time in a variety of applications for their high strength, light weight, cost effectiveness and degradability. The fiber which serves as a reinforcement in reinforced plastics may be synthetic or natural. In this connection, an investigation has been carried out to make use of Aramide/Glass/Onion fibers. The present work describes the development and characterization of mechanical properties of Aramide/Gl...

  3. Effect of fine to coarse aggregate ratio on the rheology and fracture energy of steel fibre reinforced self-compacting concretes

    Indian Academy of Sciences (India)

    Mert Yücel Yardimci; Bülent Baradan; Mehmet Alı Taşdemır

    2014-12-01

    In this study, the influence of aggregate grading and steel fibre properties on the flow properties and fracture energy of steel fibre reinforced self-compacting concrete (SFRSCC) has been investigated. Two types of hooked-end steel fibres at three different dosages (20, 40 and 60 kg/m3) were incorporated into self-compacting mixtures having similar paste contents but different fine to coarse aggregate (FA/CA) ratios (0.94, 1.72 and 2.50 by weight). Besides the flowability and passing ability of fresh concrete, the mechanical properties of hardened concrete including the fracture energy have also been investigated. The relations between flexural parameters and fibre orientation were established by image analysis technique. Test results showed that hooked-end steel fibre inclusion into the plain self-compacting concrete negatively affects the flowability and passing ability of themixture. Increasing FA/CA ratio enhances these rheological parameters and provides better fibre orientation. On the other hand, increasing FA/CA ratio decreases the fracture energy of plain SCC mixtures and the fibre incorporated series which were less affected from fibre inclusion follow the same trend with the plain SCC. The proper FA/CA ratio for the best rheological and mechanical performance depends on the fibre content, aspect ratio and their influence on the flowability of the mixture. In order to obtain better fibre orientation and hence higher fracture energy, relatively higher FA/CA ratios should be used when the fibre content and aspect ratio are relatively high.

  4. Ibuprofen-loaded poly(trimethylene carbonate-co-ε-caprolactone) electrospun fibres for nerve regeneration.

    Science.gov (United States)

    Pires, Liliana R; Guarino, Vincenzo; Oliveira, Maria J; Ribeiro, Cristina C; Barbosa, Mário A; Ambrosio, Luigi; Pêgo, Ana Paula

    2016-03-01

    The development of scaffolds that combine the delivery of drugs with the physical support provided by electrospun fibres holds great potential in the field of nerve regeneration. Here it is proposed the incorporation of ibuprofen, a well-known non-steroidal anti-inflammatory drug, in electrospun fibres of the statistical copolymer poly(trimethylene carbonate-co-ε-caprolactone) [P(TMC-CL)] to serve as a drug delivery system to enhance axonal regeneration in the context of a spinal cord lesion, by limiting the inflammatory response. P(TMC-CL) fibres were electrospun from mixtures of dichloromethane (DCM) and dimethylformamide (DMF). The solvent mixture applied influenced fibre morphology, as well as mean fibre diameter, which decreased as the DMF content in solution increased. Ibuprofen-loaded fibres were prepared from P(TMC-CL) solutions containing 5% ibuprofen (w/w of polymer). Increasing drug content to 10% led to jet instability, resulting in the formation of a less homogeneous fibrous mesh. Under the optimized conditions, drug-loading efficiency was above 80%. Confocal Raman mapping showed no preferential distribution of ibuprofen in P(TMC-CL) fibres. Under physiological conditions ibuprofen was released in 24 h. The release process being diffusion-dependent for fibres prepared from DCM solutions, in contrast to fibres prepared from DCM-DMF mixtures where burst release occurred. The biological activity of the drug released was demonstrated using human-derived macrophages. The release of prostaglandin E2 to the cell culture medium was reduced when cells were incubated with ibuprofen-loaded P(TMC-CL) fibres, confirming the biological significance of the drug delivery strategy presented. Overall, this study constitutes an important contribution to the design of a P(TMC-CL)-based nerve conduit with anti-inflammatory properties. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23950030

  5. Modified Multiwall Carbon Nanotubes with Nanolumps for Nanocomposite Reinforcement

    Science.gov (United States)

    Wen, J. G.; Lao, J. Y.; Li, W. Z.; Ren, Z. F.; Department Of Physics Team

    2002-03-01

    The quality of the bonding between a polymer matrix and carbon nanotubes is critical in the development of carbon nanotube reinforced polymer composites. In this paper, we modified multiwall carbon nanotubes by growing boron carbide (a covalent bonding compound) nanolumps on carbon nanotubes to enhance load transfer from matrix to carbon nanotubes. Experimental results demonstrated that boron carbide nanolumps with the required morphology were formed on multiwall carbon nanotubes by a solid state reaction between boron and carbon nanotubes. The reaction is localized so that the integrity of the structure of carbon nanotubes is maintained. We also found that inner layers of multiwall carbon nanotubes are bonded to boron carbide nanolumps probably through covalent bonding. Therefore, these multiwall carbon nanotubes with boron carbide nanolumps are expected to be the ideal nano-scale reinforcement to improve load transfer between carbon nanotubes and the polymer matrix. For comparison, other nanolumps such as crystalline MgO, amorphous B2O3 are also grown on nanotubes.

  6. Carbon Fiber Reinforced Carbon Composite Valve for an Internal Combustion Engine

    Science.gov (United States)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor)

    1999-01-01

    A carbon fiber reinforced carbon composite valve for internal combustion engines and the like formed of continuous carbon fibers throughout the valve's stem and head is disclosed. The valve includes braided carbon fiber material over axially aligned unidirectional carbon fibers forming a valve stem; the braided and unidirectional carbon fibers being broomed out at one end of the valve stem forming the shape of the valve head; the valve-shaped structure being densified and rigidized with a matrix of carbon containing discontinuous carbon fibers: and the finished valve being treated to resist oxidation. Also disclosed is a carbon matrix plug containing continuous and discontinuous carbon fibers and forming a net-shape valve head acting as a mandrel over which the unidirectional and braided carbon fibers are formed according to textile processes. Also disclosed are various preform valves and processes for making finished and preform carbon fiber reinforced carbon composite valves.

  7. Effect of Loading Rate on the Behaviour of Partially Pyrolyzed Basalt Fibre Reinforced Composite

    Czech Academy of Sciences Publication Activity Database

    Halasová, Martina; Chlup, Zdeněk; Černý, Martin; Strachota, Adam; Sucharda, Zbyněk; Dlouhý, Ivo

    Montecatini Terme : CIMTEC, 2014. [CIMTEC 2014. Ceramics Congress /13./. 08.06.2014-13.06.2014, Montecatini Terme] R&D Projects: GA ČR GAP107/12/2445 Institutional support: RVO:68081723 ; RVO:67985891 ; RVO:61389013 Keywords : pyrolysis * basalt fibre * impact loading Subject RIV: JI - Composite Materials

  8. Application of WST-method fore fracture testing of fibre-reinforced concrete

    DEFF Research Database (Denmark)

    Löfgren, Ingemar; Olesen, John Forbes; Flansbjer, Mathias

    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 ...... 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 of...... Technology, Department of Structural Engineering and Mechanics; and § SP – the Swedish National Testing and Research Institute. Two different mixes were investigated; the difference between the mixes was the fibre length (Mix 1 with 40 kg of 35 mm long fibres and Mix 2 with 40 kg of 60 mm long fibres). The...

  9. High strength fibre reinforced concrete: static and fatigue behaviour in bending

    NARCIS (Netherlands)

    Lappa, E.S.

    2007-01-01

    Recently, a number of high strength and ultra high strength steel fibre concretes have been developed. Since these materials seem very suitable for structures that might be prone to fatigue failure, such as bridge decks, the understanding of the static and fatigue bending behaviour is vital. In orde

  10. Determination of the minimum size of a statistical representative volume element from a fibre-reinforced composite based on point pattern statistics

    DEFF Research Database (Denmark)

    Hansen, Jens Zangenberg; Brøndsted, Povl

    2013-01-01

    In a previous study, Trias et al. [1] determined the minimum size of a statistical representative volume element (SRVE) of a unidirectional fibre-reinforced composite primarily based on numerical analyses of the stress/strain field. In continuation of this, the present study determines the minimum...

  11. The Use of Fibre Reinforced Composites (Frcs in Periodontal Splinting & the Natural Tooth Pontic (NTP in the Management of Advanced Periodontal Disease

    Directory of Open Access Journals (Sweden)

    Ian Kerr

    2013-12-01

    Full Text Available This article uses a series of case studies to examine the use of fibre reinforced composite splints in the management of advanced gum disease that has led to mobility and imminent exfoliation of teeth. The case studies show the various techniques for producing a durable aesthetic splint and how to use these principles in the production of a natural tooth pontic.

  12. Carbon Fiber Reinforced, Zero CME Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Technical Abstract: This project proposes to develop moisture insensitive, high performance, carbon fiber laminates for future missions. Current space-qualified...

  13. Carbon fiber/carbon nanotube reinforced hierarchical composites: Effect of CNT distribution on shearing strength

    DEFF Research Database (Denmark)

    Zhou, H. W.; Mishnaevsky, Leon; Yi, H. Y.;

    2016-01-01

    The strength and fracture behavior of carbon fiber reinforced polymer composites with carbon nanotube (CNT) secondary reinforcement are investigated experimentally and numerically. Short Beam Shearing tests have been carried out, with SEM observations of the damage evolution in the composites. 3D...... multiscale computational (FE) models of the carbon/polymer composite with varied CNT distributions have been developed and employed to study the effect of the secondary CNT reinforcement, its distribution and content on the strength and fracture behavior of the composites. It is shown that adding secondary...... CNT nanoreinforcement into the matrix and/or the sizing of carbon fiber/reinforced composites ensures strong increase of the composite strength. The effect of secondary CNTs reinforcement is strongest when some small addition of CNTs in the polymer matrix is complemented by the fiber sizing with high...

  14. Fabrication and properties of carbon network reinforced composite fuel

    International Nuclear Information System (INIS)

    Zirconium dioxide composites reinforced with 3D glassy carbon foam was fabricated using Spark Plasma Sintering (SPS) with a heating rate of 100degC/min and a uniaxial pressure of 50 MPa at 1500degC, 1600degC, and 1700degC, respectively. The effect of carbon foam on the thermal properties of the ZrO2 composites was investigated. In addition, the effect of the sintering temperature on the densification of the composites was also investigated and the optimized sintering temperature was identified. The microstructures of 3D carbon foam reinforced ZrO2 composites showed that the 3D shape of carbon foam was retained after the sintering process, and the ZrO2 was homogeneously distributed within the 3D carbon foam. At the interfaces between the 3D carbon foam and ZrO2, neither a chemical reaction nor a new phase formation was detected by Scanning Electron Microscopy (SEM) and X-ray Diffractometry (XRD). The thermal diffusivity of carbon foam reinforced ZrO2 composites measured at 1100degC was increased by 47% and reached to 0.66 mm2s-1 and the thermal conductivity was increased by 50% and reached to 2.428 W/m-K. (author)

  15. Investigation of damage in laminated carbon fibre composites using high resolution computed tomography

    OpenAIRE

    Wright, Peter Michael

    2011-01-01

    Laminated fibre reinforced polymer matrix composites have been used in design and manufacture for more than 50 years, exploiting desirable material properties such as high specific strength and stiffness, enabling large weight savings to be made on structural components. To take full advantage of this class of materials a comprehensive knowledge of behaviour under different service conditions is required. This thesis illustrates the degree to which this is currently achieved, and describes th...

  16. Experimental study on fire protection methods of reinforced concrete beams strengthened with carbon fiber reinforced polymer

    Institute of Scientific and Technical Information of China (English)

    HU Kexu; HE Guisheng; LU Fan

    2007-01-01

    In this paper,two reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymer (CFRP)and attached with thick-painted fire resistant coating were tested for fire resistance following the standard fire testing procedures.The experimental results show that the specimen pasted with the insulated layer of 50 mm in thickness could resist fire for 2.5 h.It is also demonstrated that the steel wire mesh embedded in the insulated layer can effectively prevent it from cracking and eroding under firing.

  17. An Adaptive Neuro-Fuzzy Inference System Based Modeling for Corrosion-Damaged Reinforced HSC Beams Strengthened with External Glass Fibre Reinforced Polymer Laminates

    Directory of Open Access Journals (Sweden)

    P. N. Raghunath

    2012-01-01

    Full Text Available Problem statement: This study presents the results of ANFIS based model proposed for predicting the performance characteristics of reinforced HSC beams subjected to different levels of corrosion damage and strengthened with externally bonded glass fibre reinforced polymer laminates. Approach: A total of 21 beams specimens of size 150, 250×3000 mm were cast and tested. Results: Out of the 21 specimens, 7 specimens were tested without any corrosion damage (R-Series, 7 after inducing 10% corrosion damage (ASeries and another 7 after inducing 25% corrosion damage (B-Series. Out of the seven specimens in each series, one was tested without any laminate, three specimens were tested after applying 3 mm thick CSM, UDC and WR laminates and another three specimens after applying 5mm thick CSM, UDC and WR laminates. Conclusion/Recommendations: The test results show that the beams strengthened with externally bonded GFRP laminates exhibit increased strength, stiffness, ductility and composite action until failure. An Adaptive Neuro-Fuzzy Inference System (ANFIS model is developed for predicting the study parameters for input values lying within the range of this experimental study.

  18. Non-linear elastic behaviour of carbon fibres of different structural and mechanical characteristic

    Directory of Open Access Journals (Sweden)

    ISIDOR M. DJORDJEVIC

    2007-05-01

    Full Text Available Five types of polyacrylonitrile, PAN, based carbon fibres, differing in modulus, breaking strain and in crystallite orientation, have been studied. Non-Hookean behaviour was investigated by computing the tangent tensile and compression moduli as a function of strain, from the axial stress–strain response obtained in standard tensile, compression, as well as in modified flexural tests of unidirectional carbon/ epoxy composites. The dependences of the tensile modulus on tensile strain of the carbon fibres were extracted from data obtained in single-filament tensile tests. Analytical expressions for the tensile modulus–tensile strain and compression modulus–compression strain dependences in the performed test were deduced. The structural characterization of the carbon fibres was performed by X-ray diffraction on bundle of parallel fibres. The interlayer spacing d002 and the apparent lateral dimension of the crystallites Lc were deduced by processing the 002 diffraction profiles. The established modulus–strain dependences were correlated with the fibre characteristics (breaking strain and mean modulus values, as well as with the characteristic of the 002 diffraction profile and the d002 and Lc values.

  19. Physical and mechanical characterization of radiation-curable carbon fibre composites

    International Nuclear Information System (INIS)

    Radiation processing is the utilization of ionizing radiation, usually photons or electron beams, to produce useful physical and chemical changes in a material. A potential application for electron beam processing for composite manufacturing is for curing carbon fibre prepregs. These prepregs, carbon fibres or fabrics preimpregnated with liquid polymer resin, are commonly used in many industries, including aircraft and aerospace, automotive, electronics, construction and various commercial products. The objective of this experimental program is to design and manufacture a radiation-curable polymer-carbon fibre prepreg that meets the typical mechanical and physical property specifications set by the aircraft industry. This paper describes our current work in the design, manufacture and characterization of radiation-curable prepregs

  20. External reinforcing of fiber concrete constructions by carbon fiber tapes

    OpenAIRE

    S.V. Klyuyev; Yu.V. Guryanov

    2013-01-01

    Strengthening the concrete and reinforced concrete structures with carbon fiber tapes is very actively applied in Europe nowadays. In Russia composites based on carbon fiber have also widely spread recently. The main advantages of these materials for strengthening structures are its high specific strength (strength-weight ratio) and strength-to-density ratio.Experimental studies on strengthening and restoration of the constructions were held. Flexible fiber concrete constructions based on man...