Composite materials are produced by combining two dissimilar materials into a new material that may be better suited for a particular application than either of the original material alone. Many of our modern technologies require materials with unusual combination of properties that cannot be met by the conventional materials . This is very true for materials that are needed for the aerospace, underwater and automotive application. Many composite materials are composed of just two phases one is termed the matrix, which is continuously surrounded by the other phase, often called the dispersed phase . Fibrereinforcedcomposites are extensively used in present day technology because of its extensive benefits, Technologically the most important composites are those in which the dispersed phase is in the form of a fibre. Design goal of fibrereinforcedpolymer often include high strength and /or stiffness on a weight basis. Fibrereinforcedcomposites with exceptionally high specific strengths and moduli have been produced that utilize low density fibre and matrix materials. Composite laminates offer alternative material design solutions in terms of specific strength and stiffness allowing important weight savings. Polymercomposites also offer significant freedom to the designer by allowing, optimizing the strength and stiffness of a component or structure for a particular application. Furthermore, thermoplastic resins present increased interest due to their economic and mechanical advantages, such as easy fabrication, unlimited shelf life, intrinsic recyclability, high toughness and increased moisture resistance. Recently an increasing use of compositesreinforced with different types of fibres has occurred, owing the following advantages: they are strong enough, light in weight, abundant, non-abrasive and cheap . It is well known that the mechanical properties
The experimental study on the effect of fibre loading and orientation on physical, mechanical and water absorption behaviour of jute and cotton/glassfibrereinforced polyester based hybrid composites leads to the following conclusions: 1. The successful fabrications of a new class of polyester based hybrid compositesreinforced with jute ,cotton and glassfibre have been done. The present investigation revealed that fibre loading and orientation significantly influences the different properties of composites. The maximum hardness, flexuralstrength and tensile strength,impact strength,hardness,density is obtained for compositesreinforced with 20wt% jute fibre loading. 2. The water absorption rate gradually increases with increase in fibre loading irrespective of fibreorientation. The maximum water absorption is obtained for composites with 25 wt% fibre loading irrespective of fibreorientation. As far as effect of fibreorientation on the water absorption of composites is concerned there is not much influence is observed.
There is a gradually increase both in the number of applications being found for fibrereinforced plastics and in the variety of fibre-resins systems that are available to designers. Some of these systems are useful, however, only in highly specialized situations where limitations such as high investment and brittle failure behavior are considered secondary to such qualities as low density, high rigidity and high strength. By mixing 2 or more varieties of fibres in a resin to form a hybrid composite it may be possible to create a material possessing the combined advantages of the individual components and at the same time mitigating their less desirable qualities . In addition it is possible to fulfill the properties of such materials to suit specific necessities. A. Hybrid Composites
The GFRP bars used in this study were provided by V-ROD® Australia  and were manufactured by pultrusion process of E-glass fibres impregnated in modified vinyl ester resin. High modulus (HM) GFRP bars (Grade III, CSA S807-10) of varying nominal diameters were considered in this study (Figure 2): 12.7 mm, 15.9 mm, and 19.0 mm nominal diameter sand- coated GFRP bars with fibre contents in percent by weight of 84.1, 83.9, and 84, respectively . Straight (without anchor head) and headed (with anchor head) GFRP bars were used to investigate the influence of the anchorage system on the flexural behaviour of the specimens. The guaranteed properties of GFRP bars as reported by the manufacturer  are given in Table 1. The tensile strength and elastic modulus were calculated using nominal cross-sectional area. For the purpose of comparison, 16.0 mm deformed steel bars were utilised as longitudinal reinforcement in one of the tested beams. Table 2 presents the mechanical properties of the steel bar.
This research is proposing new yarn fibreorientation from 300 tex size of yarn fibre kenaf. S1 as the optimum stacked layer orientation is compared with group R in terms of flexural and tensile analysis. Generally, group S shows better result as compared to group R for tensile and flexural properties. The flexuralstrength for S1 has improved by 152% compared to R1 (the highest in group R). Meanwhile, there was an improvement of 127% for S1 compared to R3 (the highest in group R) for flexural modulus. Similar trend occurred in tensile properties. S1 improved to 250% and 179% for tensile strength and tensile modulus respectively as compared to the highest value in group R. This result exhibits that small size of yarn produces a higher yarn density for each woven area given a better finding on tensile and flexural properties. Indirectly, vacuum infusion process is reported to give more advantages compared to hand lay-up process for woven kenaf composites. However, unidirectional type fibre tends to exhibit outstanding mechanical properties compared to woven kenaf composites as shown in Table 1 [18, 23, 24]. The volume of fibre in each area of kenaf may affect and influence the mechanical properties of kenaf composites . Higher volume fibre exhibits better flexural and tensile properties for natural fibres.
A generally accepted manifestation of adhesion is the mechanically measured interfacial shear strength (IFSS). Over the years a number of experimental techniques have been developed and studied in order to assess the IFSS such as the microbond test and the single fibre pull-out test . It is also known that the IFSS can be influenced by chemicals, such as silane coupling agents. This has in turn led to a number of investigations surrounding both glass and carbon fibre-reinforcedpolymercomposites using the microbond test method [4-5]. In the present work, the effect of various silane coupling agents and full sizings on the IFSS of the composite was investigated using the microbond test. While it is debated whether micromechanical testing methods do in fact provide a true measure of adhesion there can be no doubt that they serve as a useful tool for screening various combinations of fibre and matrix and work as a reliable comparative method.
components left within the matrix system after curing. An excess of unreacted epoxy groups is shown by the downward peak at 4530 cm -1  in Figure 12 for samples where R < 1.0 . For ratios with excess amine (R > 1), the reactive epoxy groups would statistically be less likely to bond with the amines provided by the silane due to the abundance of free primary amines already present within the matrix system, thus resulting in fewer bonds forming across the interface. For these ratios the curing reaction would also be dominated by the primary amines, with little secondary amine bonding, resulting in a more branched polymer matrix structure. This would result in significant levels of unreacted secondary amines within the system. nIR was used to confirm this as shown by the downward peak at 6460 cm -1  in Figure 13, with the peak increasing as R increased. Depending on the R ratio it was also possible to have unreacted primary amine within the matrix as shown by the downward peak in Figure 14. This abundance of unreacted molecules as well as the branched structure would increase the polymer free volume due to the poor packing ability of the amine molecule, again leading to a decrease in the T g [43,44]. However, we would expect the negative
The urge to improve the properties of composite materials has prompted material scientists to investigate composites with lower reinforcement size, leading to the developments of composites. Depending on the type of polymer matrices, they are classified as thermosetting composites and thermoplastic composites. For the last three decades, the use of PMC has increased tremendously and this drastic growth is expected to continue in the future. The composites possess many useful properties such as high specific stiffness and strength and strength, dimensional stability, adequate electrical properties and excellent corrosion resistance. The implications are easy transportability, low stress for rotating parts, high ranges for rockets and missiles, which make them attractive for both the civil and defence applications. The composite industry is currently dominated by thermosetting resins
indicate the orientation of the longitudinal ply direction with respect to the loading direction, the order of the num- bers indicate the stacking sequence and the subscript out side the brackets, how many times the sequence is repeated through the laminate. The deduced elastic material proper- ties are displayed in Table 1 and the strength parameters (with respect to damage) are displayed in Table 2. The parameters needed to evaluate the Puck failure criterion are displayed in Table 3, here the fracture angle for pure transverse compression, θ fp , is obtained from literature for
Carbon fiber reinforced mortar (CFRM) and carbon fiber reinforced cement (CFRC) are composites that have high flexural quality and durability and low drying shrinkage, notwithstanding this they have great electrical properties, for example, voltage-touchy impact. Ease pitch carbon filaments is satisfactory for scaffolds, other structural designing structures furthermore for cladding for structures, Kucharska and Brandt. In the districts with Corrosive impact of marine climate and solid winds (e.g. in Japan) CFRC is utilized as a part of scaffold auxiliary components for preferred toughness over it would be conceivable utilizing steel filaments Fibre-reinforcedpolymer (FRP) bars can be used to replace steel reinforcement conventional steel has the inherent problem of corrosion as a result of which it undergoes expansion and concrete cracking may occur; therefore, FRP rebar may be used as an alternate. The use of this fibres excludes the problem of corrosion and increases the ductility of the FRP-reinforced concrete beams but the load deflection was found to be higher. (Mohamed S. Issa, Ibrahim M. Metwally, Sherif M. Elzeiny 2010).
ABSTRACT: Concrete is one of the most widely used construction material, it is usually associated with Portland cement as the primary binder. The production of one tonne of cement emits approximately one tonne of carbon-di-oxide in to the atmosphere which contributes to the global warming. On the other hand huge volume of fly ash is disposed in to the landfill which affects the surface bodies of fresh water and aquifers. An effort in this regard is the development of Geopolymer concrete. In this work low calcium fly ash based geopolymer is used as the binder instead of Portland cement paste to produce concrete. This paper presents the results of an experimental program on the mechanical properties of Geopolymer Concrete Composites (GPCC) containing Fly ash (FA), alkaline liquids and glass fibres. Alkaline liquid to fly ash ratio was fixed as 0.4 with 100% replacement of OPC. Glass fibres were added to the mix in 0.01%, 0.02% and 0.03% by volume of concrete. Based on the test results, the Geopolymer concrete composites have relatively higher strength in short curing time (one day) than the Geopolymer concrete and ordinary Portland cement concrete.
For the fabrication of the square hollow section (SHS), Auto-Fix 1710A and its hardener Auto-Fix 1345B epoxy resin is used. The mixing ratio for the resin is 1:1 as specified by the supplier. By using vacuum assisted resin transfer molding (VARTM), KFRE SHS with size of 40mm × 40mm with length of 350mm was fabricated. In the process of fabrication, each mat was weighed in order to have equivalent weight in each layer. Then, it was cut into the size of mould length and specimen perimeter width. Before the mats were put into the mould, the thickness of the fibre mat used was estimated by placing them between vacuum bags and the measurement was done by using micrometer. For the current study, mats thickness of 5mm has been used. Two types of fibreorientation has been used namely unidirectional and random orientation KFRE. As the desire thickness has achieved, the mats were rolled on deformable madrel which made of the sequence of bagging film-nylon mats (uniform distributor)-peel ply film at its outer most.
Fuqua and Ulven investigated the different MAPP loading (0, 5 and 10 w/t %) effects on tensile properties of corn chaff fiber reinforced polypropylene composites . They also investigated the effect of various treatments, silane z-6011, silane z-6020 and 5 w/t % MAPP, on corn chaff fiber & distilled dried grains (DDGS) reinforced polypropylene composites . It was found that 5 w/t % MAPP yielded the optimum value for the composites in term of tensile strength and modulus as shown in Figures 23 and 24 respectively . The strength reduction observed with high MAPP loading was caused by the interaction between the compatibilizer (MAPP) and the fibre/matrix system. The anhydride units of MAPP maintain loop confirmations within the composite systems, since they all can act with equal probability with the cellulose in the corn fibers. Coupled with MAPP’s low average molecular weight, the interaction between the PP matrix and MAPP becomes dominated principally by Van der Waals’ forces; since chain entanglement of PP and MAPP is virtually impossible. MAPP that is not utilizes for fibre/matrix adhesion and is therefore mechanically harmful to the composites, which leads credence to the significant performance variation between 5 and 10 w/t % loadings. However, through the use of 5 w/t % MAPP, it was found that the tensile properties of the composites increase, especially tensile strength compared to neat resin and those untreated.
The Young‟s modulus of short glassfibre polypropylene composites is mainly determined by the fibre content, fibre stiffness, fibreorientation, fibre length and matrix stiffness [5, 7]. It has been shown that the stiffness of glass fibres is not reduced by heat treatment [2, 8, 9]. Thus all properties mentioned above were constant in the produced composites except for the fibre length. Similar to previous work on discontinuous glassfibre polypropylene composites , the Cox-Krenchel equation (equation 1) was used to predict the stiffness of the composites which were produced in the current study.
Polyesters are mainly used in chemical industry such as lubricants, plasticisers, stabilisers, coatings etc. The demand of these applications is increasing day by day. In earlier days, polymers and their composites are derived from petroleum feedstocks. As the demand of polymers increases, there is a need of renewable resources as alternate petroleum feedstocks. Vegetable oils are a renewable raw material. The polymers synthesised from vegetable oils are cheap, most abundant feedstock, low toxic, biodegradability etc than the petroleum based polymers . Punnal oil is the naturally occurring vegetable oil and is extracted from the seed of the Calophyllum inophyllum tree. It contains 92% triglycerides. The major fatty acids present in punnal oil are palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid .The unsaturation present in punnal oil are responsible for the chemical modifications . Therefore, the double bonds in the punnal oil have to be converted to more reactive functional groups such as epoxide groups, acrylate groups, hydroxyl groups
Steel fibre-reinforced concrete is normally cheaper and easier than any other fibres to use a form of standard reinforced concrete. Commonly used reinforced concrete utilises steel bars that are placed in the liquid cement, which requires a great potential of preparation work but results in making much durable concrete. Steel fibre-reinforced concrete uses fibres which are thin and similarly uses wires made up of steel to mixed in with the cement. This force the concrete with much greater structural strength reduces cracking, other failures and helps protect against extreme cold.
First, the banana fibre is extracted from the banana tree. Then, the drying process of the banana trunks are carried out by keeping it under the sunlight up to two weeks. After the drying process gets completed the banana trunks are soaked in diluted NaOH solution for two hours so that the wettability of the fibre can be improved. If it is not soaked for two hours, the fibre won’t get separated from the unwanted part also. Then the fibres are dried by keeping it in an oven. After banana fibres have dried completely, they are cut horizontally in order to get the required specifications that are needed to produce the composite that we desire. Then roller machines are used to thin the fibres which will make the process of weaving easier. Then the fibres are woven as per the requirement. The woven banana fibres are shown in Fig. 1.
may be flakes or in powder form. Concrete and wood particle boards are examples of this category Because the fiber orientation directly impacts mechanical properties, it seems logical to orient as many of the layers as possible in the main load-carrying direction. While this approach may work for some structures, it is usually necessary to balance the load-carrying capability in a number of different directions, such as the 0°, +45°, -45°, and 90° directions shows a photomicrograph of a cross-plied continuous carbon fiber/epoxy laminate. A balanced laminate having equal numbers of plies in the 0°, +45°, – 45°, and 90° degrees directions is called a quasi-isotropic laminate, because it carries equal loads in all four directions. Composites are not always the best solution. This part was machined from a single block of aluminum in about 8.5 hours and assembled into the final component in five hours. Such a part made of composites would probably not be cost competitive. Advanced composites are a diversified and growing industry due to their distinct advantages over competing metallics, including lighter weight, higher performance, and corrosion resistance. They are used in aerospace, automotive, marine, sporting goods, and, more recently, infrastructure applications. The major disadvantageof composites is their high cost.
Uni-directional carbon fibrereinforced (UD-CFRP) composite laminate ply was modeled in ANSYS Workbench software with a 0/90˚ fibreorientation. Size of 20×20×4 mm UD-CFRP square plate with a pilot hole of 0.5 mm diameter was modeled with 8 prepreg layers of thickness 0.5 mm each, as shown in Fig. 2. Pilot hole was designed to avoid the interaction of chisel edge of twist drill with the work piece so that the simulation time could be reduced.
The beam wrapped with continuous sheet of CFRP resisted the maximum torsional moment of 17.52kNm. The percentage increase in C1700FL(1)90 is 138.36% with respect to control beam. When comparing B1700FL(1)90 with CFRP-BFRP hybrid beams ie, C200B50(1)90, B200C50(1)90, C125B125(1)90, C150B100(1)90 and B150C100(1)90 showed increased torsional strength. The percentage increase in torsional strength with respect to control beam for the above mentioned hybrid beams is 128%, 85.95%, 110.20%, 117.74% and 86.74% for 20%, 80%, 50%, 40% and 60% replacement BFRP respectively. In no case, the replacement with BFRP strips could resist more torsional capacity than the continuous CFRP wrapped beam ie, C1700FL(1)90. The percentage decrease with respect to C200B50(1)90, B200C50(1)90, C125B125(1)90, C150B100(1)90 and B150C100(1)90 is 21.9%, 4.34%, 11.81%, 21.6% and 8.6%. The torsional resistance capacity can be increased by continuous wrapping with CFRP sheets and by replacing some strips of BFRP in between CFRP strips but its ultimate torsional strength can never go above C1700FL(1)90.