Glass Fiber Polymer Composites Research Articles

Effect of Abrasive Water Jet Parameters on the Drilling of Aluminum Foam Sandwiched with Glass Fiber Polymer Composites

To attain good geometric shape and size, machining of high-strength metal Fiber laminate becomes inevitable in the field of automotive industries. In this research, aluminum foam sandwiched with glass fiber reinforced polymer (GFRP) composites fabricated using a hand layup process. The glass Fiber composite was fabricated using aluminum foam with a thickness of 1 mm. The effect of abrasive water jet parameters such as pressure (P), stand-off distance (L), and nozzle diameter (D) on material removal rate (MRR) and Kerf angle (Ka) and Surface roughness were investigated. The results were compared without aluminum foam composites. Glass fiber composites with aluminum foam reduced the kerf angle by 44.18 %, and surface roughness (Ra) by 41.77 % as compared with glass fiber composites without aluminum foam. From the investigation, it was noticed that maximum pressure (220 Bar) and minimum stand-off distance (1mm) were optimum parameters for reducing the kerf angle and surface roughness. Also, Optical images of the hole were analyzed for surface quality.

Compression strength analysis of glass fibre polymer composites filled with brown algae powder compared to glass fibre reinforced polymer composite

The current investigation intends to compare the compression strength analysis of glass fiber composites filled with brown algae filler. The material involved in this work is a glass fibre composite filled with and without brown algae filler. 40 specimens were tested by using selected parameters using the universal testing machine. In this work, the control group was a glass fiber epoxy composite and the experimental group was a brown algae-filled glass fiber-reinforced polymer. The mean compressive strength obtained for the brown algae-filled glass fibre reinforced polymer is, whereas it is for the Glass fibre reinforced polymer with the significant value is 0.018 (p<0.05). Within the scope of this investigation, experimental data reveals that strength in compression is high when the glass fiber-reinforced composite is filled with brown algae powder.

New Anchorage Technique for GFRP Flexural Strengthening of Concrete Beams Using Bolts-End Anchoring System

The concept of external glass FRP composite confinement is a current process for strengthening concrete beams subjected to static loads. End anchorage glass FRP composites of 80 mm width and 90–130 mm length with different thicknesses (2.4 and 4.8 mm) have been fixed at the bottom of beams with bolts of various diameters (6 and 10 mm). For this purpose, the behavior of beams strengthened with bolt-end anchoring glass fiber polymer composites (BEGFPC) has been analyzed. It is concluded that the load capacity of the BEGFPC beams is improved by increasing the end-anchorage glass FRP composite thickness (about 98–188%). In addition, the BEGFPC system with bolts of 6 mm diameter has significantly improved the flexibility of beams. In contrast, the 10 mm bolts in diameter give a high ultimate load, whatever their quantity. Therefore, combining bolts with diameters of 6 and 10 mm would be the best solution for increasing the ultimate load and ductility of the retrofitted beams. Depending on the number and bolts' arrangement, there is also an enhancement in the crack patterns by changing from intermediate flexural failure to shear failure in beams.

A study on thermal conductivity and thermogravimetric analysis of glass fiber epoxy resin composites modified with silicon carbide and copper nanoparticles

Composite materials are futuristic materials, the strength, properties and applications decides the composition of composite materials. The study of physical, mechanical and thermal properties of composites provides the more scope for their wide applications. Silicon carbide nanoparticles (SiC-NPs) and Carbon nanoparticles (Cu-NPs) Polymer composites are prepared by hand layup machining moulding technique using epoxy resin and glass fibre. The study of thermogravimetric analysis (TGA) was carried using STA 7300 and TGA 8000 for varied % fillers reinforced in glass fibre polymer composites. The weight loss noticed 64.5 to 94.5% in Cu-NPs composites and 44.2 to76.8% weight loss in SiC-NPs at 750 °C. The overall thermal stability observed in SiC-NPs composites and more thermal stability observed in 15% and 20% SiC-NPs composites. There is a less weight loss in SiC-NPs composites as compared to Cu-NPs composites. The study of thermal conductivity was carried out by FOX50 heat flow meter (HFM), for both SiC-NPs and Cu-NPs composites thermal conductivity increases with increase of fillers percentage. SiC-NPs composites have shown higher thermal conductivity values compared to Cu-NPs composites. Results obtained from the FOX 50 HFM have shown that at higher percentage SiC and Cu nanoparticle fillers thermal conductivity increases by 20% compared ERGF composites without fillers.

Structural analysis of sol-gel derived TiO2 nanoparticles: a critical impact of TiO2 nanoparticles on thermo-mechanical mechanism of glass fiber polymer composites

The incorporation of inorganic nanoparticles with thermosetting epoxy polymer is an emerging field of research over the past few years. It is well analyzed that epoxy matrix is brittle in nature that shows rapid crack initiation and rapid propagation without increasing applied stress value. Therefore, researchers are showing their interest in nanoparticles embedded epoxy composites to improve their fracture resistance (brittleness and toughness). In this investigation, the dispersion of TiO2 nanoparticles at different weight fractions (0-2 %) with glass fiber reinforced epoxy composites is performed to enhance structural and thermo-mechanical properties. The TiO2 nanoparticles are prepared by sol-gel method and structural analysis of TiO2 nanoparticles shows greater interfacial bond with epoxy matrix and glass fibers due to fine dispersion of nanoparticles. From obtained results, a significant enhancement in their tensile strength (38.56 %), flexural strength (30.52 %), inter-laminar shear stress (25.22 %), impact strength (327.10 %), micro-hardness (48.53 %) and fracture energy (40.19 %) with a minimal detrimental effect on toughness was revealed for GFRP-T1.0 compare to GFRP-T0.0 composite laminates. The stiffness and rigidity also improved up to 52.72 % and 34.13 % respectively for GFRP-T1.5 compare to GFRP-T0.0 composite laminates. The effects of nanoparticles contents and clustering size on thermal stability and glass transition temperature of developed composites are observed by thermo-gravimetric analysis. The surface morphology of TiO2 nanoparticles is characterized by transmission electron microscope (TEM) while the dispersion of nanoparticles and failure of developed composites were analyzed by scanning electron microscopy (SEM).

The influence of seawater on mechanical properties of hybrid carbon and glass fiber polymer composites

The fiber reinforced polymer (FRP) composites come in contact with seawater in marine applications. This will result in water intake by FRP composite and influence the overall properties. In this investigation, the mechanical properties of plain glass, plain carbon and a hybrid carbon/glass FRP composites were evaluated in dry and seawater aged conditions. The plain and hybrid composite with stacking sequence [G2C2G]S were fabricated. The result revealed that the tensile, flexural and impact strength of seawater aged hybrid composites [G2C2G]S was decreased by 6.4%, 11.2% and 11.1% compared to in dry condition. Thus, the decrease in strength of fiber reinforced polymer composite in seawater is affects the performance of composites.

Capacitance measurements on integrated conductors for detection of matrix cracks in GFRP

For the reliable and cost-efficient application of glass fibre polymer composites in structural applications, knowledge of the damage state of the material during operation is necessary. Within this work, a structural health monitoring method based on in-situ electrical capacitance measurements is presented, which enables damage monitoring in glass fibre reinforced polymers. For this purpose, individual glass fibre rovings in a non-crimp fabric were replaced by carbon fibre rovings at regular intervals. Additionally, specimens with solid or stranded copper conductors were manufactured to gain insights into the influences of conductor material and composition. The modified fabrics were implemented as 90 ∘ layers of [0/904]s glass fibre polymer cross-ply laminates. To monitor the progressive damage, conductive rovings were contacted, forming the capacitor walls of interleaved capacitors. Carbon fibre conductors show higher sensitivity of the capacitance to crack formation than solid or stranded copper conductors. Capacitance decrease measured in-situ during tensile tests on specimens with carbon fibre conductors shows a high correlation with crack initiation, further crack formation and speed of crack evolution. An analytical model can describe the correlation based on the assumptions of an ideal plate capacitor. Thus, the structural health monitoring method developed in this work can reveal in-situ knowledge of the material damage state.

Review on history and characterization of polymer composite materials

Composite materials have excellent mechanical and physical properties that are now-a-days being used in all engineering applications such as aeronautical, automotive, electronics, marine and sports applications etc. This is due to their characteristics of light weight and superior mechanical properties. The aim of this review article is to provide comprehensive review on widely used glass and jute fiber polymer composites. The effect of type of fiber used, their volume fractions, orientation, and method of manufacturing, filler, hardener and chemical treatment were studied and reported in this paper. This paper concludes that use of natural fiber composites has been also responsible for latest development in research in the composite industry.

Synthesis and mechanical properties of pistachio shell filler on glass fiber polymer composites by VARIM process

The present study investigated the effect of Pistachio shell particles on the mechanical behavior of chopped glass fiber/epoxy polymer composite. The composite laminates were manufactured using vacuum assisted resin infusion molding (VARIM) method. In this work the glass fiber of chopped strand mat used as reinforcement with density of 450 gsm and matrix material of epoxy resin. The concentration of filler material of pistachio shell particles were selected as 0, 1, 2, and 3 wt% respectively. The high speed mechanical stirrer was used to mix the pistachio shell particles into the polymer material of epoxy resin. The particle size of the powdered pistachio shells was analyzed and morphological studies are carried of the prepared specimens using a Scanning Electron Microscopy (SEM). The addition of pistachio shell particle enhanced the tensile and flexural strength of the prepared laminates. The flexural strength was increased by 14% with addition of 1 wt% of pistachio shell particle.

Synthesis and Wear Characterization of Reinforced Glass Fiber Polymer Composites with Epoxy Resin Using Granite Powder

Recent research scenario reveals that the amalgamations of micro and nanoceramic fillers into fiber reinforced polymer composites have improved their performances in an excellent manner. In this research work, an investigation was attempted at in analyzing the wear behavior of glass fiber reinforced with epoxy resin using granite powder as a filler material in varying weight percentage ranging from 0-5%. Structural morphology of the prepared laminates was studied using SEM. Epoxy resin which was taken as matrix material was reinforced with a combination of chopped and woven roving mat glass fibers. Pin on disc method was applied for completing the wear test at different constraints of load, sliding distance and velocity for the investigation. Influence of granite powder in the composite was synthesized by calculating the specific wear rate and weight loss occurring at varying speed and normal load were applied on it. On examining by SEM worn surface wear rate of the prepared laminate at 5 wt% of granite provided better wear resistance as compared to other compositions and characterizations of worn surfaces.

Modelling the effect of temperature on the probabilistic stress–life fatigue diagram of glass fibre–polymer composites loaded in tension along the fibre direction

Predicting the fatigue performance of composites has proven to be a challenge both conceptually, due to the inherent complexity of the phenomenon, and practically, because of the resource-intensive process of fatigue testing. Moreover, mechanical behaviour of polymer matrix composites exhibits a complicated temperature dependence, making the prediction of fatigue performance under different temperatures even more complex and resource intensive. The objective of this paper is to provide a method for the prediction of fatigue life of glass–polymer composites loaded in the fibre direction at various temperatures with minimal experimental efforts. This is achieved by using a static strength degradation approach to fatigue modelling, where only two parameters (including static strength) are temperature dependent, in conjunction with relationships for these two fatigue model parameters temperature dependence. The method relies on fatigue data at a single temperature and simple static tests at different temperatures to predict the effects of temperature on the material’s fatigue behaviour. The model is validated on experimental data for two unidirectional and one woven glass–epoxy composites and is found to accurately predict the effect of temperature on fatigue life of composites. A method to obtain probabilistic stress-life [Formula: see text] fatigue diagrams including temperature effects is also presented.

Comparative assessment of the explosive blast performance of carbon and glass fibre-polymer composites used in naval ship structures

An experimental investigation is presented into the explosive blast response of fibre-reinforced polymer laminates used in naval ship structures. Blast tests using plastic explosive charges were performed in air on square target plates made of carbon-polyester, glass-polyester, carbon-vinyl ester or glass-vinyl ester laminates, which are composite materials used in naval ships. The laminates were dynamically loaded by shock waves of increasing pressure and impulse, and the deformation, damage and residual mechanical properties were determined. The amount of blast-induced damage and the post-blast mechanical properties depend on both the fibre reinforcement and polymer matrix. E-glass laminates have higher resistance to blast-induced delamination cracking and tow rupture than carbon fibre composites. Furthermore, glass or carbon fibre laminates with a vinyl ester matrix have superior blast damage resistance compared to composites with a polyester matrix. The higher damage resistance is attributed to the higher flexural strain energy capacity and interlaminar fracture toughness properties of laminates containing glass fibres or vinyl ester matrix.

Finite element estimates of viscoelastic stiffness of short glass fiber reinforced composites

An unstructured mesh Galerkin finite element method is used to obtain estimates of the viscoelastic moduli of short glass fiber reinforced polymer composites. Periodic Monte Carlo models with 125 identical inclusions are studied. Both spheroidal and spherocylindrical inclusions are considered. The estimates are compared against predictions of the dilute approximation, Mori-Tanaka (MT) and self-consistent (SC) models. It is shown that at small fiber fractions, the dilute approximation (Eshelby) model is exact. However, for the axial stiffness the dilute regime is limited to fiber volume loadings of a few tens of a percent while typical short glass fiber polymer composites have fiber loadings from 10 to 20 percent. It is found that in this concentrated regime, both MT and SC models give excellent predictions for all but the axial stiffness modulus. To assess the feasibility of reliable stiffness and vibration damping design of composite structures from short fiber reinforced polymers, Monte Carlo models with various fiber orientation distribution (FOD) states are studied. It is shown that the quick Voigt (constant strain) orientation averaging procedure gives excellent viscoelastic stiffness predictions provided that the finite element estimates are used for the required moduli of the basis FOD state with fully aligned fibers.

Effect of Blast Furnace Slag on Mechanical Properties of Glass Fiber Polymer Composites

The use of polymer fibre reinforced Composite materials is finding applications day by day in engineering fields such as aero-space, automotive, aircrafts constructions, etc. Glass fibre polymer composites are reinforced with granulated blast furnace slag (GBFS) ball milled to size of 5nm in different weight fractions, i.e. (0%, 5%, 10% and 15%) and fabricated by using hand lay-up technique. These fabricated slabs are cut into required dimensions and the tests for mechanical properties like Tension test, Compression test, Flexural test Impact test and Hardness test were performed. Tension test, compression test and Flexural test were performed on Computerized Universal Testing Machine (UTM), Impact test was performed for Izod and Charpy specimens and Hardness test was performed on Brinell's Hardness Testing Machine. From the experimental results obtained, it was noticed that the mechanical properties were enhanced when the blast furnace slag percent was increased and also among these percentages of blast furnace slag, the specimen having 15% was possessing highest properties.

Hybrid and hierarchical nanoreinforced polymer composites: Computational modelling of structure–properties relationships

Hybrid and hierarchical polymer composites represent a promising group of materials for engineering applications. In this paper, computational studies of the strength and damage resistance of hybrid and hierarchical composites are reviewed. The reserves of the composite improvement are explored by using computational micromechanical models. It is shown that while glass/carbon fibers hybrid composites clearly demonstrate higher stiffness and lower weight with increasing the carbon content, they can have lower strength as compared with usual glass fiber polymer composites. Secondary nanoreinforcement can drastically increase the fatigue lifetime of composites. Especially, composites with the nanoplatelets localized in the fiber/matrix interface layer (fiber sizing) ensure much higher fatigue lifetime than those with the nanoplatelets in the matrix.

Effects of moisture on glass fiber-reinforced polymer composites

Glass fiber polymer composites are used in wind turbine blades because of their high-specific strength and stiffness, good fatigue properties, and low cost. The wind industry is moving offshore to satisfy economies of scale with larger turbines. High humidity in this environment degrades mechanical performance of wind turbine blades over their lifetime. Here, environmental moisture conditions were simulated by immersing glass fiber-reinforced polymer specimens in salt water for a period of up to 8 years. The mechanical properties of specimens were analyzed before and after immersion to evaluate the degradation mechanisms. Single-fiber tensile testing was also performed at different moisture conditions. The water-diffusion mechanism was studied to quantify the diffusion coefficients as a function of salt concentration, sample geometry, and fiber direction. Three degradation mechanisms were observed: polymer plasticization, fiber stress corrosion, and interface degradation, where the latter was found to be the most detrimental for wind-industry applications.

Microscale damage mechanisms and degradation of fiber-reinforced composites for wind energy applications: results of Danish–Chinese collaborative investigations

Recent research works in the area of experimental and computational analyses of microscale mechanisms of strength, damage and degradation of glass fiber polymer composites for wind energy applications, which were carried out in the framework of a series of Sino–Danish collaborative research projects, are summarized in this article. In a series of scanning electron microscopy in situ experimental studies of composite degradation under off-axis tensile, compressive and cyclic loadings as well as three-dimensional computational experiments based on micromechanics of composites and damage mechanics, typical damage mechanisms of wind turbine blade composites were clarified. It was demonstrated that the damage mechanisms in the composites strongly depend on the orientation angle of the applied loading with the fiber direction. The matrix cracking was observed to be the main damage mechanism for tensile axial (or slightly off-axis axial) loading; for all other cases (off-axis tensile, compressive and cyclic tensile loadings), the interface debonding and shear control the damage mechanisms.

Improved strain sensing performance of glass fiber polymer composites with embedded pre-stretched polyvinyl alcohol–carbon nanotube fibers

Polyvinyl alcohol–carbon nanotube (PVA–CNT) fibers differing on their pre-stretching condition were embedded in glass fiber reinforced plastic (GFRP) composites and used as strain sensors for damage monitoring of the composite. Strain sensing of the composite was made by the in situ measurement of the embedded fiber’s electrical resistance change during the mechanical tests. Four glass fiber composite plates were manufactured; each one had embedded a different type of produced PVA–CNT fibers. The multi-functional materials were tested in monotonic tensile tests as well as in progressive damage accumulation tests. The electrical resistance readings of the PVA–CNT fibers were correlated with axial strain values, taking into account the induced damage of the composite. It has been demonstrated that increasing the fiber’s pre-stretching ratio, its electrical resistance response increases due to higher degree of the CNTs alignment in the PVA matrix. Higher fiber pre-stretching degree enables the better strain monitoring of the composite due to higher measured electrical resistance change values noticed for the same applied axial strain values. To this end, it enables for the better monitoring of the progressive damage accumulation inside the composite.

Effect of temperature and time on mechanical and electrical properties of HDPE/glass fiber composites

In recent years, composites based on glass fiber reinforced polymer have been widely used in order to meet increasing durability and safety regulations, particularly in the power cable, automotive and plane industry. In this paper, mechanical and electrical properties of high density polyethylene (HDPE) and HDPE containing glass fiber polymer composites were investigated and compared at different temperatures. Composite materials were prepared with the hot pressing method. Tensile strength, % elongation and the modulus of elasticity (or Young’s modulus) were determined for each sample at different temperatures. In addition to this, at different temperatures τσ and τE have mechanical and electrical lifetime respectively, corresponding to mechanical tension (σ) and electrical strength (E), and this was investigated for each sample. As compared to the mechanical and electrical properties of neat HDPE, HDPE/0.5 % glass fiber composites have been found to have better mechanical and electrical durability.

Ultrasonic testing of natural fibre polymer composites: effect of fibre content, humidity, stress on sound speed and comparison to glass fibre polymer composites

This work investigates the application of ultrasonic testing UT in evaluating natural fibre thermoplastic composites NFTC. The characterisation of sound propagation speed in the composite is intended to be a tool for evaluating the NFTC namely fibre content, fibre distribution and external factors’ effects like relative humidity and stress. The quality of fibre distribution homogeneity can be assessed by mapping the returning signals of the emitted longitudinal ultrasonic wave. This study presents the measured sound speeds for a composite system of flax and polypropylene (PP). Flax fibre loadings rang from 0 to 60 wt%. Humidity factor is studied at 10, 50 and 95 % relative humidity RH levels. Different stress levels of 0, 10 and 20 MPa are applied on composite samples in an orthogonal direction to the longitudinal wave propagation direction. Using non-immersion: contact UT; an increasing linear trend of calculated longitudinal sound speed by 1 % is indicated per every 11 wt% increase of the applied flax fibres. This rate increased with more RH levels. More stress decreases the sound speed but in a trend parallel to the non-stressed samples. Finally, the distribution quality of the fibre is assessed using the ultrasonic technique. Results are compared with the reference corresponding PP–glass fibre composite. The high E-modulus and the density of glass fibres are opposite factors. Thus, the sound speeds for the both cases of 30 wt% flax and glass fibres are close and not more than 0.6 % different.