Glass Fiber Reinforced Epoxy Matrix Research Articles

Experimental Design and Analysis of MWCNT, Nanoclay and Zinc Oxide Nanofillers on Bi-directional-Chopped Stranded Glass Fibre Reinforced Epoxy matrix on Mechanical Properties using Multi Response Performance Index Approach

Experimental Design and Analysis of MWCNT, Nanoclay and Zinc Oxide Nanofillers on Bi-directional-Chopped Stranded Glass Fibre Reinforced Epoxy matrix on Mechanical Properties using Multi Response Performance Index Approach

Experimental Design and Analysis of MWCNT, Nanoclay and ZnO Nanofillers on Bi-Directional-Chopped Stranded Glass Fibre Reinforced Epoxy Matrix on Mechanical Properties using L9 and L18 Taguchi’s Orthogonal Technique

Stealth, mechanical and thermal properties, resistance to fire by limiting oxygen and retarding flame can lead to save several human lifes travelling and working in civil, commercial as well as defence air transport and could even develop drone and aircraft meant to escape enemy countries radar tracing and monitoring range. GFRP play very important role in engineering application. The composite manufactured using nanofillers have found to posses better propeties in certain application. In the present work, MWCNTs, Nanoclay and ZnO have been used in GFRP. The developed material can be a promising replacement of composites being used for structural applications in the aerospace sector and space technology apart from the automotives to impart light weight, superior bending and tensile strength. Testing of GFRP infused nanofillers was conducted to obtain the ultimate tensile strength and flexural bending strength of the composite. Experimental design with three Nanofillers as parameters at three levels for optimization of output characteristics with superior properties for structural applications was done using Taguchi’s L9 and L18 orthogonal arrays. ANOVA Analysis was also performed for both L9 and L18 arrays. The effects of three nanofillers infused GFRP was investigated and their impact on tensile and flexural strength were evaluated.

Fabrication and Mechanical Testing of Glass Fiber Reinforced Epoxy Matrix Composites Modified with Powdered Metallic Fillers

Composite materials made up of polymer matrix reinforced with synthetic fibers have gained popularity of late owing to their enhanced mechanical properties. However, very little work is reported to date on metals being used as filler material. Research gaps were obtained pertaining to the use of metallic fillers in synthetic fiber reinforced polymer composites. This paper demonstrates an attempt to fabricate composites made of Epoxy polymer matrix and E-glass fiber reinforcement with Mild Steel in its powdered form as fillers. Composites are prepared in varying weight percentages of the filler in the order of 2 wt. %, 4 wt. % and 6 wt. %. Hand layup method is employed for fabricating these composites which are later subjected to compression. Further, the samples are machined according to ASTM D3039 standard for tensile test and ASTM D256 standard for Izod impact test. Hardness test is also performed using a Shore D Durometer and these properties are compared with the unfilled samples. The results indicated that the weight percentage of the filler clearly influenced the mechanical properties of the developed composites. This study also revealed that the hardness and tensile strength of these composites improved with the incorporation of fillers up to 2 wt. % whereas, the impact strength improved up to 4 wt. %. Thereafter, there was a decline in their impact and tensile properties. However, hardness marginally increased beyond 4 wt. %. This area is open for research with regard to their usability under tribological, high temperature or magnetic conditions.

Dynamic mechanical analysis for assessment of carbon fillers in glass fiber epoxy composites

AbstractThe effect of incorporation of micron sized aluminum trihydrate, multi‐walled carbon nanotubes, and graphene nano platelets into glass fiber reinforced epoxy matrix is investigated using dynamic mechanical analysis. The objective of the investigation was to develop polymer central core of high temperature low sag transmission conductor. The effect of individual and hybrid carbon fillers on the viscoelastic properties of the epoxy composites is investigated and discussed. The storage modulus of the glass reinforced epoxy increases by 20% at room temperature due to incorporation of carbon nanofillers. In glass transition region, the increase is higher between 40% and 60% and it varies up to 90% in the rubbery region. Key attributes of carbon filler addition are limited enhancement of storage modulus at room temperature, higher enhancement over glassy, glass transition, and rubbery regions. The carbon fillers extend the temperature range of the glassy region. The cross‐link density, filler efficiency, and degree of entanglement of fibers are estimated to understand the implications of the carbon fillers on the viscoelastic properties. The loss modulus peak of glass epoxy composite increases from 2800 to 3900 MPa with carbon fillers and the increase in glass transition temperature is 47°C. Incorporation of carbon fillers leads to increase of damping factor peak from 0.2 to 0.28. Cole–Cole plots have established the inherent heterogeneity of epoxy systems due to the presence of carbon fillers. Prediction models for storage modulus and damping factor have been proposed to highlight the influence of geometry and size of carbon filler.

Microscale evaluation of epoxy matrix composites containing thermoplastic healing agent

Among the strategies to produce healable thermosetting systems is their modification by the addition of thermoplastic particles. This work investigates the influence of poly(ethylene-co-methacrylic acid) (EMAA) on fiber-matrix interfacial properties of a glass fiber reinforced epoxy matrix composite. Epoxy-EMAA interactions were evaluated using differential scanning calorimetry (DSC) and infrared spectroscopy. The effects of EMAA on the epoxy network formation were evidenced by changes in glass transition temperature, cure kinetics and alteration of chemical groups during cure. Interfacial shear strength (IFSS) measurements obtained by single fiber pull-out tests indicate similar interfacial properties for pure and EMAA modified epoxy. Additionally, the potential for self-healing ability of an EMAA modified epoxy was demonstrated. However, IFSS after a healing cycle for the EMAA modified epoxy was lower as compared to the pure epoxy, because of the lower fiber-EMAA interfacial shear strength. So, thermoplastic healing agents has not only to fill cracks in the matrix material, but also have to be optimized regarding its interface properties to the reinforcing fibers.

Effects of recovered brown alumina filler loading on mechanical, hygrothermal and thermal properties of glass fiber–reinforced epoxy polymer composite

This study investigates the efficiency of recovered brown alumina (RBA) particles filled in epoxy glass-fiber composites. The RBA particles were obtained from grinding wheel rejects with the help of the mechanical crushing process. Recovered particles finer than 120 grit were used as particulate filler for composite preparation. Composites were processed through a hand-layup technique by varying RBA filler loading percentages (0, 5, 10, 15, and 20 wt.%) in a glass fiber–reinforced epoxy matrix. Physical, mechanical, water absorption, and thermal properties of the composites were tested experimentally. By suitable addition of RBA, it is possible to tailor the shore-D hardness, tensile modulus, flexural strength, flexural modulus, and maximum degradation temperature. The 20%-filled RBA composite shows the maximum flexural strength of 382 MPa, and the shore-D hardness value was 85. The fracture surface shows a failure mechanism dominated by matrix cracking and debonding of fiber/particles from the interface. Hygrothermal testing of the RBA20-filled composite reveals 9% and 4% reduction in tensile and flexural properties. The thermal stability of the glass fiber–reinforced composite improves as the filler percentage increases. Maximum thermal stability of 435°C was observed in 20%-filled RBA polymer composite.

Low velocity impact behaviour of surface treated glass fibre reinforced epoxy matrix hybrid composites

This task is intended to perform impact tests with a low-speed test on the specimen. The tests are carried out to improve their tolerance of impact so that they can be used for realistic applications in the real world. The specimen is treated with acid and a base for one day. By the hand-laying method, the specimen shall be prepared. Microscopy of the electron scanning is carried out in order to receive data on the surface topography of the affected specimen. Various low speed experiments have been evaluated in this paper.

Strain prediction and analysis of GF/epoxy composite cylindrical shells with various internal defects

ABSTRACT A three-dimensional (3D) finite element model is built to investigate the strain response of glass fibre reinforced epoxy matrix (GF/epoxy) cylindrical shells. Internal defects including delamination (IDD) and fracture defects (IFD) with different areas are considered. Progressive damage models are adopted to predict the circumferential strain (CS) and longitudinal strain (LS) and stress distribution. Results show that CS is the dominant strain when the GF/epoxy cylinders contain IDD, and the maximum LS and Mises stress position coincides with the loading position. The maximum Mises stress increases with the increasing of IDD area. However, when the cylinders contain IFD are subjected to internal pressure, the CS and LS are close. The maximum LS and Mises stress are located at the upper end of the cylinder and the defect position, respectively. The results will be useful for damage detection and health assessment of cylindrical shells containing internal defects.

Effect of Glass Fiber Stacking Sequence on the Notch Sensitivity of Glass Fiber Reinforced Epoxy Matrix Composites

This research article investigated the effect of stacking sequence of glass fibers on the notched and unnotched tensile strength of glass fibers plies reinforced epoxy matrix composites fabricated by the hand lay-up technique. The orientation of glass fabrics was kept at [(0/90)]5, [(45/-45)]5 and [(0/90), (45/-45), ]s and all the laminates were prepared using five plies for different stacking sequences with fiber volume content of 38.6 vol.% with different ratios of the specimen hole diameter to the specimen width with three different values (0.1, 0.2, 0.5). The notch sensitivity of these composites was evaluated applying Whitney-Nuismer mathematical model. The results indicated that the composites with [(0/90)]5 stacking sequence displays the highest tensile unnotched strength, whereas the composites with [±45°]5 stacking sequence displays the least strength. Moreover, the notch sensitivity of [±45°]5 composites is almost higher than those of other stacking sequences with different D/W ratios. On the other hand, the notch sensitivity of [(0/90), (45/-45), ]s composites is slightly lower than those of [(0/90)]5 composite structures for different D/W ratios. Moreover, SEM micrographs indicates the most common failure modes for [(0/90), (45/-45), ]s and [(45/-45)]5 are more significant delamination and matrix cracking than that of [(0, 90)]5.

ZnO Nanostructured Interphase for Multifunctional and Lightweight Glass Fiber Reinforced Composite Materials under Various Loading Conditions

The optimal mechanical performance of glass fiber reinforced epoxy matrix composites typically relies on the suitability of its interfacial properties to the applied loading conditions. The contras...

Performance analysis of wind turbine blade materials using nanocomposites

Nanoparticle reinforced composites (nanocomposites) are gaining popularity among researchers and industries due to its incredible properties. Nanocomposites have wide a range of applications in variety of domains. Glass fiber reinforced epoxy matrix composites are highly preferred for the construction of wind turbine blades due to its favourable characteristics. This paper mainly investigates the feasibility of SiO2 and Al2O3 based nanocomposites particularly for the application of wind turbine blades. The work presented in this paper deals with the fabrication and detailed analysis of nano SiO2 and Al2O3 dispersed E-glass fiber/ AW 106 epoxy composites. Composites were fabricated with a hand layup process by varying the percentage of nanomaterials. In order to analyze the properties of the materials tensile test, fatigue test, and hardness test were performed. From the test results, nanocomposite with 1% Al2O3 showed relatively good tensile strength and fatigue strength with optimum hardness. Analysis using SEM and EDX were done to study the microstructure of the composites. Further, computational modelling and analysis were done with ANSYS software package to get an insight on the suitability of these composites for wind turbine blade applications under different loading conditions.

The Effect of Moisture on the Properties of Glass Fiber Polymer Matrix Composites with MoS2 and CaCO3

The mechanical properties and water absorption behavior of a pure glass fiber reinforced epoxy matrix and a glass fiber reinforced epoxy filled composites immersed into a tap water were investigated. The main purpose of this experiment is addition of two different powdered fillers (CaCO3 and MoS2) into the epoxy matrix and comparing the properties of pure GFRP and filled GFRP. The composites specimens with fillers absorb less water when compared to pure GFRP specimens at room temperature. Water absorption curves and equilibrium moisture content were determined. The composites exhibit a positive deviation from the Fickan’s law with the addition of fillers into the matrix. The influence of water uptake has significant effect on the reduction of mechanical properties. It is observed that 3% filled MoS2 in epoxy matrix has less uptake of water and the tensile strength decreased is 3% , flexural strength decreased up to 18% and shear strength is 42% decreased when compared to CaCO3 filled composites and unfilled glass fiber reinforced polymer composite.

Mechanical characterization of hybrid laminates composites

Abstract In this recent work the important on mechanical and thermal studies on hybrid composites using glass fiber reinforced epoxy matrix with alkali treated Luffa cylindrica has been experimentally investigated. The Composite laminates were fabricated in the form of 3 plies by hand lay-up technique incorporate with Hexagonal Boron Nitride nano particles. Effect of boron nitride on the tensile, flexural and compressive strength for the composite materials was studied. TGA analysis on the composite materials was performed. It is found that the optimum mechanical properties were increased up to 1.0% of boron nitride added hybrid composite.

Experimental and numerical investigation of the strain response of the filament wound pressure vessels subjected to pressurization test

AbstractThis article presents the strain response of glass fiber reinforced epoxy matrix pressure vessels subjected to pressurization test. Three filament wound composite pressure vessels with different dimensions are manufactured by fiber winding processing, and the pressurization tests of these pressure vessels are performed. The stain of the inner/outer surface of the vessels during the pressurization tests is recorded. A progressive damage model is built based on the 3D Hashin failure criteria by finite element method (FEM) to predict the strain response of the composite pressure vessels. Fundamental mechanical tests that including the tensile, double cantilever beam, and three‐point end notched flexure tests of the composite laminates are carried out to determine the strength and stiffness parameters used in the FEM. The results show that the circumferential strain of the three composite pressure vessels is greater than the longitudinal strain. The maximum stress and strain occurs at the head of the pressure vessels. The predictions of FEM match the experimental results well, and the strain differences between FEM and experiments of the pressure vessels are less than 12%.

Self-Sensing Polymer Composite: White-Light-Illuminated Reinforcing Fibreglass Bundle for Deformation Monitoring.

The goal of our research was to develop a continuous glass fibre-reinforced epoxy matrix self-sensing composite. A fibre bundle arbitrarily chosen from the reinforcing glass fabric in the composite was prepared to guide white light. The power of the light transmitted by the fibres changes as a result of tensile loading. In our research, we show that a selected fibre bundle even without any special preparation can be used as a sensor to detect deformation even before the composite structure is damaged (before fibre breaking).

Evaluation of the failure responses of filament wound and pre-preg wrapped glass fiber/epoxy composite tubes under quasi-static torsional loading

This paper introduces an experimental and numerical investigation into hollow cylindrical thin-walled glass fibre reinforced epoxy matrix composite shafts produced by using both pre-preg wrapping and filament winding methods. The filament wound samples were manufactured with four different helix angles ([±30]FW, [±45]FW, [±60]FW, and [±75]FW ), whereas [0, 90]PP pre-pregs was utilised for producing the wrapped kind of samples. In order to assess the quasi-static failure responses, the samples were subjected to increasing amount of torsional load at a fixed angular rotation speed. The experimental findings of [±30]FW, [±45]FW, and [±60]FW samples were found to be very compatible with those obtained via Finite Element Analysis (FEA). Contrarily, the numerical model were not able to describe accurately the load—displacement behaviour of [±75]FW and [0, 90]PP with the exception of the initial loading phase. [±45]FW was found as the most favourable option for designers in terms of torsional stiffness. Whereas, those characterised by [±30]FW, and [±60]FW exhibited very close torsional resistances in a difference range of only 5%. [0, 90]PP exhibited the lowest average torsional failure resistant and stiffness but the highest average rotation angle before rupture.

Influence of cement particles on the mechanical and buckling behavior of laminated GFRP composites with variation of end conditions of buckling

Mechanical behavior of particle-loaded laminated composites depend upon the type of matrix, filler, reinforced fibers and architecture of fibers. Further, buckling behavior of a laminated composite varies with its end conditions, i.e. free-free or fixed-fixed. Failure mechanisms like delamination, debonding and fiber fracture vary with the end conditions of buckling. Presence of hard filler may also change the buckling behavior. Thus, in the present article, the mechanical and buckling behavior of cement loaded woven glass fiber reinforced epoxy matrix composites were investigated. Cement was varied as 1%, 3% and 5% by weight of epoxy. Thickness of composites were also varied as 3.1 mm, 4.4 mm and 6.3 mm by varying the number of reinforced glass fiber mats. Tensile, Izod impact and Vickers micro-hardness tests and, buckling tests under free-free and fixed-fixed conditions were performed to assess the mechanical and buckling behavior respectively. Fractured composites were analyzed under scanning electron microscope (SEM). The results showed that tensile strength decreased and hardness increased with increase in percentage of cement. Composites with minimum thickness showed lowest tensile strength. Critical buckling load increased with increase in thickness of composites for both end conditions. However, the nature of variation of buckling load with the percentage of filler varies for every thickness. SEM images showed that damage of composites mainly involved fiber breakage and delamination. Cement particles were effective in deflecting the advancing crack.

Monitoring the Damage State of Fiber Reinforced Composites Using an FBG Network for Failure Prediction.

A structural health monitoring (SHM) study of biaxial glass fibre-reinforced epoxy matrix composites under a constant, high strain uniaxial fatigue loading is performed using fibre Bragg grating (FBG) optical sensors embedded in composites at various locations to monitor the evolution of local strains, thereby understanding the damage mechanisms. Concurrently, the temperature changes of the samples during the fatigue test have also been monitored at the same locations. Close to fracture, significant variations in local temperatures and strains are observed, and it is shown that the variations in temperature and strain can be used to predict imminent fracture. It is noted that the latter information cannot be obtained using external strain gages, which underlines the importance of the tracking of local strains internally.

Assessing glass-fiber modification developments by comparison of glass-fiber epoxy composites with reference materials: Some thoughts on relevance

Any approach for designing composites with improved mechanical properties finally has to be assessed for respective improvements achieved. Glass-fiber reinforced epoxy matrix laminates consist of several constituents. Pretreatment of the constituents, the processes combining the matrix with the reinforcing fibers as well as the curing of the laminate may all have an effect on the resulting mechanical or fracture properties of the composites. In this contribution, the authors present selected cases from recent materials developments, dealing with glass-fiber epoxy laminates for which a thermal fiber treatment for desizing was compared with chemical solvent desizing. While desizing with a solvent and resizing with another type of sizing yielded tensile and interlaminar shear properties comparable to those of laminates prepared from as-received fibers, but lower for desized fibers, resizing after thermal desizing treatment exceeding +500 ℃ yielded lower properties for laminates from desized and resized fibers, but roughly in the same percentage difference as chemically desized and resized fiber laminates. This raises the question of how material or interface modifications in glass-fiber epoxy composites can best be compared for an assessment of the improvements achieved by the fiber treatments or the fiber–matrix interface modifications.

Woven Glass Fiber Composites with Aligned Carbon Nanotube Sheet Interlayers

This investigation describes the design, fabrication, and testing of woven glass fiber reinforced epoxy matrix laminates with aligned CNT sheets integrated between plies in order to improve the matrix dominated through thickness properties such as the interlaminar fracture toughness at ply interfaces. Using aligned CNT sheets allows for a concentration of millimeter long CNTs at the most likely point of laminate failure. Mode I and Mode II interlaminar fracture toughness of various CNT modified samples were investigated using double cantilever beam (DCB) and end notched flexure (ENF) experiments, respectively. Short beam strength (SBS) and in-plane tensile properties of the CNT modified samples were also investigated. Moderate improvement was observed in Mode I and Mode II fracture toughness at crack initiation when aligned CNT sheets with a basis weight of 0.354 g/m2were used to modify the ply interface. No compromise in the in-plane mechanical properties of the laminate was observed and very little improvement was observed in the shear related short beam strength of the CNT modified laminates as compared to the control samples. Integration of aligned CNT sheets into the composite laminate imparted in-plane and through thickness electrical properties into the nonconductive glass fiber reinforced epoxy composite laminates.