Crawley E.F., J. Compos. Mater.  examined experimentally and theoretically that the natural frequencies and mode shapes of 8 ply graphite/epoxy cantilever plates of various laminates and aspect ratio. Erklinğ.  investigated the natural frequency and damping properties consisting of various combinations of S-glass, carbon, and Kevlar fibres. They conducted experiments on hybrid composites under the combinations of clamped (C), free (F) and simply supported (SS) boundary conditions. They showed that maximum and minimum frequency values occurred in C-FC-F and C-F-F-F edge conditions respectively. Pushparaj Pingulkar, Suresha B.  worked on the natural frequencies and mode shapes of plate of glass fiber reinforced polymer composites (GFRPCs) and carbon fiber reinforced polymer composites (CFRPCs) are obtained using the commercial finite element analysis software (ANSYS). S.U.Ratnaparkhi, S.S.Sarnobat. experimentally and theoretically studied that the natural frequency increases with increase in the fiber orientation. This paper is about effect of vibration analysis of stamped sheets with reinforcement of epoxyglass fiber on it. In this study, analysis plane sheet, circular shape sheet and trapezoidal shape sheet with and without reinforcement of epoxyglass fiber are taken in order to analyse the effect on natural frequency. Present study involves in research in the domain of fixed-fixed boundary condition of composite plate and to check the changes in stiffness and in mode shapes.
Single fiber fragmentation tests of epoxy microcomposites based on single uncoated, GO coated and rGO coated glass fiber revealed that microcomposites containing GO interphase deposited at 10V/cm offered a higher interfacial shear strength (ISS) with the value being 218% than that obtained with uncoated fibers. The factors associated to the increase in adhesion strength were evaluated to be related to the physical and chemical nature of the GO based interphase. For the prior case, it was found that the higher the thickness of the GO coating, the higher was the roughness value of the coating hence contributing towards the “physical” bonding between the fiber and matrix. Moreover, the friction force microscopy (FFM) analysis on GO coated fiber revealed that the coating possessed an interfacial strength of 130 MPa which was 4 times higher than the highest ISS value of the microcomposite thus confirming the positive effect of enhanced interfacial adhesion in epoxy/glass composites. The “chemical” contribution towards the improvement of ISS was governed to be the oxygen functional groups attached to the GO nanosheets which was confirmed by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis.
Extensive use of GFRP composites are seen in sports equipments and aircraft engine blades due to their high strength and fracture toughness. Rathinasabapathi et al  have explored the use of nano fillers and predicted an increase in the mechanical properties of fibres reinforced at suitable weights. Mostefa Bourchak et al.  have studied the impact of nano particles when added to GFRP specimens that led to an increase in fatigue strength. Dinesh kumar Rathore et al.  tested the flexural behaviour on epoxy/glass fibre composites filled with carbon nano tubes (CNTs) and found the yield of higher modulus and strength with addition of 0.1% wt. of MWCNTs. G K Arun et al.  investigated GFRP specimens added with nano fillers and found GFRP specimens doped with nano fillers tends having a better strength with low weight and resistant to wear. P.S.Shivkumar Gouda et al.  have compared the usage of nano fillers with
The failed sample was noted to have many „black lines‟ in the plane of the sample (i.e. perpendicular to the field direction) and well away from the breakdown site. It proved impossible to resolve these under the optical microscope, so an SEM analysis was attempted. Figure 4 shows a view of a black line from above and there is little to see. Figure 5 shows the view of such a line in a region where the surface has been removed to expose it to view. The line can be seen to be a 2.5 m void running alongside the glass fibre for millimetres. Figure 6 shows an elemental analysis obtained on a sample prior to ageing using an SEM. The carbon peak is quite strong, as are peaks associated with the elemental content of the glass fibres (e.g Si, Ca, Al). The same analysis taken around the „black line‟ in the failed sample, Figure (7), showed a strong reduction of the carbon peak with respect to the aluminium peak. This indicates that the black lines are not carbonised tracks such as may be produced by partial discharges. Discussion
Both Glass fiber/Epoxy rods and Carbon fiber/Epoxy rods were manufactured by Pultrusion method. The Carbon/Epoxy and Glass/Epoxy rods were subjected to tensile test and Impact test. Then, the3d modeling of Pultruded rods was done by using Unigraphics software. Static analysis was carried to determine the deflections and stresses for static loads for different materials (i.e. Carbon/Epoxy, Glass/Epoxy materials.).Analysis was done for two cases (i.e. in first case, the force was applied on the top surface of the ladder and in second case, the force was applied on the leg of the ladder.). For First case, Carbon/Epoxy material has less Von misses stress and more Factor of safety than the other material. For second case, E- glass/Epoxy material has high Factor of safety than the other material. So, it was concluded that the Ladder with Carbon/Epoxy Pultruded rods is better compare to other materials for case-1(the force was applied on the top surface of the ladder) and the Ladder with Eglass/Epoxy Pultruded rods is better than other materials for case-2.
Sandwich beams loaded in three points bending may fail in several ways including tension or compression failure of facings. In this paper , The effect of the transverse shear on the face yielding and face wrinkling failure modes of sandwich beams loaded in three points bending have been studied, the beams were made of various composites materials carbon/epoxy, kevlar/epoxy, glass/epoxy at sequence [+θ/-θ] 3s, [0°/90°] 3s. . The stresses in
RO4003® Series High Frequency Circuit Materials are glass reinforced hydrocarbon/ceramic laminates (Not PTFE) designed for performance sensitive, high volume commercial applications. RO4000 laminates are designed to offer superior high frequency performance and low cost circuit fabrication. The result is a low loss material which can be fabricated using standard epoxy/glass (FR4) processes offered at competitive prices.
The behavior of E-glass / epoxy layer composite plates under shock was studied experimentally by Mili and Necip (2001) t. They used a weight reduction impact device in their work. They evaluated the effects of pulse tip velocities and stratification order on the behavior of the composite plate. Aslan et al. (2003), Aslan and Karakuzu (2002) evaluated the dynamic behavior of fiber reinforced laminated composites exposed to low speed impact. They conducted experimental and numerical research on time-dependent analysis of glass / epoxy composites. Numerically calculated contact force-time values were compared with experimental results. They determined the importance of impact velocity, impact mass, dimensions and thickness of composite plate in low speed impact exposed composites. Baucom and Zikry (2005) examined the damage advances in E- glass composite systems in low- speed impact. Low- speed pulses were made at the same energy level until the puncture occurred in the sample, and thus obtained the greatest contact force-pulse number and energy distribution-pulse count graphs. Belingardi and Vadori (2002) examined low speed pulse behavior of glass / epoxy composite plates. One-way and braided composite material having three different orientations made tests with free dart reduction device. The pulse-energy value, the contact force-time changes were obtained and the impact behavior of the samples with different characteristics were evaluated.
The work focus on the application of FEA concept to compare the different materials for leaf spring and propose the one having higher strength to weight ratio. The materials usedfor comparisons are; conventional steel, composite E-Glass/Epoxy and carbon epoxy. In the present work deflection and bending stresses induced in the leaf springs are compared. The solid modelling of leaf spring is done in hypermesh11.0 andanalyzed using ABAQUS 10.1.
It was found that the optimal susceptibility for the epoxy encapsulation (approximately -9 ppm) lies between the susceptibility of the doped water sample and copper. This result is perhaps not surprisingly in that it is consistent with the hypothesis that minimum field broadening will occur in a uniform magnetic environment. When the epoxy susceptibility is optimized, there is a ten- fold improvement in field broadening compared to having the probe in air alone (i.e. no encapsulation). This basic effect is well-known and is the reason probe encapsulation is commonly used and reported in the literature . The results presented here go further, specifically demonstrating that field broadening is doubled when susceptibility varies from the optimal value by as little as 2 ppm. The small variation in the susceptibility of the epoxy
The six types of materials are applied to this wind turbine blade .Various modes of vibration of wind turbine blade model are observed. The first twenty natural frequencies and their mode shapes are generated for Aluminium 2024, E-Glassepoxy, Flax Epoxy, Jute polypropylene, Fiber Glass polyester, Fiberglass polypropylene of wind turbine blade at free load for round trailing edge geometry with fixed struts as boundary condition. The same procedure is repeated for the remaining gurney flap and wedge trailing edges. The mode shape frequencies and its corresponding deformation for the Aluminium material are given in Table 7.1 which are resulted from modal analysis by using ANSYS software
For the untreated kenaf-fibre/epoxy composites, it is obvious that more voids are present along the fibre-matrix interface, as shown in Figure 3, suggesting week interfacial adhesion. These areas provide spaces for moisture to occupy thus making untreated kenaf composites more vulnerable to moisture attack as compared to the treated ones (Azwa et al., 2013, Dittenber and GangaRao, 2012, Chen et al., 2009), which explains its higher initial weight loss. At lower temperature, treated kenaf- fibre/epoxy composite has better fibre/matrix bonding due to the removal of hydrophobic components of the fibre, allowing better compatibility between the kenaf fibre and the epoxy. This compatibility provides better interfacial adhesion and mechanical interlocking between the fibres and the matrix as observed in Figure 4, whereby the fibre surface is seen to be filled up by the epoxy. This improves the resistance of the composite to moisture thus, the lack of moisture leads to comparable percentage of weight loss to epoxy at temperature below 300 ºC.
Vehicles chassis consists of an assembly of all the essential parts of a truck (without the body) to be ready for operation on the road. Composite material is a material composed of two or more distinct phases (matrix phase and dispersed phase) and having bulk properties significantly different from those of any of the constituents. Different types of composite material are available and one of it is Polymer matrix composite. It is very popular due to their low cost and simple fabrication methods. It has the benefits of high tensile strength, high stiffness and good corrosion resistance etc. At present this polymer matrix composite materials are used in aerospace, automobile industries due to it high strength to low weight ratio. In this paper we design and model the heavy vehicle chassis by using Pro/Engineer software, by taking the data from the L & T heavy vehicle model by reverse engineering processes. Present used material for chassis is steel. The main aim is to replace the chassis material with E- GLASSEPOXY & S-2 GLASS. By using steel, the weight of the chassis is more compared with E- GLASSEPOXY & S-2 GLASS, since its density is more. Structural and Modal analysis is done on chassis for optimizing above parameters under 10tons load.
thermal expansion (LCTE). The results indicate that each is strongly dependent on the hardener-to-epoxy ratio and it was found that changes in IFSS can be related to changes in the thermomechanical properties of the matrix. From the results presented it is hypothesized that residual radial compressive stresses at the interface are influenced by the chemistry of the matrix system due to the changes in the properties of the matrix. The combination of these residual stresses with static friction may lead to a potential variation of the interfacial stress- transfer capability in glass-fibre reinforced epoxy composites.
This project work expresses the difference between the structures with and without damping material. The effect of damping on the performance of isotropic (steel) and orthotropic (Carbon Epoxy & E-GlassEpoxy) structures is to be analyzed by using Finite Element Analysis. The values of the static deflection for Steel Shaft, Carbon Epoxy Shaft and E-GlassEpoxy Shaft are to be compared with and without visco elastic polymer (Rubber).
Resins often tend to absorb moisture from air. As stated by Pritchard (1999), there are four factors can affect the moisture absorption of resins. The four factors are the polarity of the molecular structure, degree of crosslinking, degree of crystallinity and degree of curing. The degree of curing usually indicates the number of monomers (resin residuals) and hardeners. A recent study also found a rapid raise in temperature could enhance the moisture absorption of epoxy resins. Figure 2.3 shows the result of the moisture absorption study. The experiments carried out with several different resins in a wet environment. The temperature raised from 50 ℃ to 200 ℃ , and most of the under test specimens reached the their maximum of moisture absorption at 150 ℃ , then continually fell down as the temperature increased.
under indentation, the Young’s modulus value was varied until the FE model gave a similar sti ﬀ ness as that in the experiment. As can be seen from Table 6, due to the lower values of the e ﬀ ective Young ’ s modulus for the glass laminates, the analytically calculated critical load values are slightly lower for these laminates, compared with the carbon la- minates. However, the experimental critical load values are very similar for the glass and carbon laminates. Furthermore, the experimental maximum load levels experienced by the carbon and glass samples (after scaling) are close to each other, except for the IS test case, see Fig. 7. The ﬁrst drop is caused by initiation and immediate propagation of delamination at a number of diﬀerent interfaces that resulted in the sti ﬀ ness change. The load drops after the ﬁ rst load drop are mainly associated with delamination propagation. Later there was also some ﬁbre breakage on the tension and compression sides of the composite laminates, as evidenced by front and back surface images and C-scan images taken from di ﬀ erent stages of loading (presented later in section 3.3.). A similar damage scenario was reported in another study on quasi-static indentation of IM7/8552 epoxy laminates with a quasi- isotropic layup , where both ﬁ bre failure and delamination were reported during propagation of delamination. The maximum load is controlled by ﬁbre failure, and it appears at a larger displacement for the glass samples than the carbon samples, due to the lower sti ﬀ ness and higher strain to failure of the S-glass ﬁbres. Considering the scaled results, the percentage of the reduction in load at the ﬁrst load drop for the glass laminates is slightly less than that of the carbon laminates. As detailed in section 3.3, the variation in the induced damage is the reason for this slight diﬀerence. The area under the load–displacement curve up to the maximum load, was used to compare the energy ab- sorption capacity of the glass and carbon laminates (see Table 5). This was done for comparison purposes as it was not easy to stop the tests at the same level of damage. It is evident that the scaled S-glass/epoxy laminates demonstrate considerably higher energy absorption, with values of 1.59, 1.57, 2.20, 1.45 times more for the SS, PS, IS and R test cases, respectively. This is due to the lower stiﬀness and higher strain to failure of the S-glass ﬁ bres compared to the carbon ﬁ bres. In stages 1 and 2, the S-glass/epoxy laminates undergo more displacement at the
liquid was obtained. Four layers of fabric were impregnated with epoxy resin and placed in a mold. The laminates were fabricated by using conventional compression molding at a constant pressure of 10 kg/cm2. The mold was kept under a pressure for 4 hrs at 80°C to obtain a cured laminate. The cured sample was removed from the mold and placed in an oven for 8 hrs at 160°C for post curing. Three specimens of each series were prepared.
The composite materials chosen are woven roving Glass Fibre Reinforced Polymer (GFRP) type C- glass/Epoxy 600 g/m² and type E-glass/Epoxy 800 g/m². These woven roving materials were laminated with resin to increase their impact strength. The materials were fabricated using a hand lay-up technique with the aid of rollers. The process of preparing the compound is based on a 2:1 ratio: that is, 2 portions of epoxy to 1 portion of hardener. The epoxy resin and hardener used are from types Zeepoxy HL002TA and Zeepoxy HL002TB. For each thickness, five panels of 350mm×350mm were laminated. After the hand lay-up process, the top layer of laminate was covered with glass and four 150N weights were placed on the top of the glass. The curing process was carried out at room temperature for 48 hours. 120 specimen plates as per the Boeing Specification Support Standard BSS 7260 (100mm×150mm) for both types were cut using a CNC Router Machine. The thickness for each material is shown in Table-2.
This work presents the effects of hollow glass microsphere fillers on the mechanical behavior of glass fiber reinforced epoxy binding matrix composites. Properties like flexural stiffness, tensile strength, and scanning electron microscope, will be studied .The mechanical properties of glass fiber reinforced epoxy-resin/hollow glass-microsphere composites can be suitably tailored by using microspheres with different weight fractions. Because HGM have high specific compressive strength, low density, low moisture absorption and high thermal stability, it is mixed in glass fiber – epoxy mixture to get some useful properties which are highly useful in marine applications. Finite element analysis will be carried out on glass fiber reinforced HGM epoxy composite by ANSYS to measure up deviation between analytical and experimental result.