Glass Fiber Reinforced Polymer Composite Materials Research Articles

Acoustic Emission and K-S Metric Entropy as Methods to Analyze the Influence of Gamma-Aluminum Oxide Nanopowder on the Destruction Process of GFRP Composite Materials

Composites are materials that are widely used in industry, including yachting, railway and aviation. The properties of these materials can be modified by changing the type of reinforcement, the type of matrix, as well as the use of additives in the form of fillers and nanofillers that improve their mechanical or specific parameters. Due to the fact that these materials are often used for important structures, computational models using FEM tools may not be sufficient to determine the actual strength parameters, and what is more, to check them during operation. When designing structures made of composite materials, it is necessary to use high safety factors due to their behavior under several different types of loads, which is still difficult to determine precisely. This situation makes these structures much heavier and characterized by much higher strength properties than those that would actually be needed. In this article, the Kolmogorov-Sinai (K-S) metric entropy was used to determine the transition from the elastic to the viscoelastic state in GFRP (glass fiber reinforced polymer) composite materials without and with the addition of nanoaluminum, during a static tensile test. Additionally, the acoustic emission method was used during the research. This signal was further processed, and graphs were made of the number of events and the amplitude as a function of time. The obtained values were plotted on tensile graphs. The influence of the nano-filler on these parameters was also analyzed. The presented results show that it is possible to determine additional parameters affecting the strength of the structure for any composite materials.

Study on the Manufacturing of Composite Materials Made from Glass Fiber Reinforced Polymer (GFRP) in Indonesia for Use as Lining in Open Channels

This study explained the potential use of glass fiber-reinforced polymer (GFRP) composite materials as an alternative lined material for irrigation channels in Indonesia. Currently, only four recommended materials are used as lining in irrigation channels in Indonesia, i.e., stone masonry, concrete, soil-cement, and ferrocement. Almost all lined material's main constituents are sourced from nature/environment. The exploitation of these mined materials will impact environmental destruction. This study focused on the manufacturing process of GFRP material, GFRP surface roughness testing, and the water flow characteristics in the hydraulic model experimental testing. The manufacturing process of GFRP material used polyester resin as the polymer matrix, E-glass type with a combination of woven roving mat covered by non-woven standard mat as the glass fiber reinforcement, and manufacturing process with a combination of hand lay-up and spray-up techniques. The GFRP material product has an average surface roughness coefficient value of Ra around 5.19 to 5.97 μm. The GFRP manufacturing has a good uniform product, as the average surface roughness coefficients of GFRP material have relatively the same values. It is shown that a factory in Indonesia has sufficient capacity to manufacture GFRP material for lining in open channels. The water flow characteristics in the flume were turbulent during testing in the hydraulic laboratory. The experimental study concluded that the GFRP composite materials could be implemented as preliminary references for alternative lined material in irrigation channels in Indonesia.

Effect of drilling parameters on hole quality in drilling of pultruded GFRP composite material: Surface roughness, thrust force and delamination factor

Fiber reinforced polymer (FRP) composites are being used in a variety of areas. These materials need to be processed with some machining methods according to their usage areas, but their machinability is difficult. In this study, drilling is performed on glass fiber reinforced polymer (GFRP) composite produced by pultrusion with coated and uncoated drill. Then, surface roughness (SR), delamination factor (Fd) and thrust forces were investigated. Microstructures of chips formed during drilling were investigated and their effects on surface roughness were determined. Three distinct feed rates and cutting speeds were selected as machining parameters. Investigations showed that feed rate had a more significant effect on surface roughness, delamination factor and thrust force. It was understood that when the cutting speed increased, the surface roughness, thrust force and delamination factor decreased. Better results were obtained with TiN coated drills compared to uncoated drills.

Prediction of resisting force and tensile load reduction in GFRP composite materials using Artificial Neural Network-Enhanced Jaya Algorithm

This work presents an experimental and a numerical studies on the effect of the phenomenon of porosity on the mechanical properties of Glass Fiber Reinforced Polymer (GFRP). In a first part, material elaboration, as well as its characterization using a three-point bending test to extract the basic mechanical properties of the material, is considered. In a second part, a finite element model is created to simulate the problem of air bubbles broadly. Several cases of different shapes and sizes are simulated. The results show a significant effect on the reduction of load in both tensile and bending cases as the size of the bubbles increases. Furthermore, the second part includes the application of the Artificial Neural Network-Enhanced Jaya Algorithm (ANN-E JAYA) to predict the reduction of the tensile load as a function of different crack lengths obtained from an Extended Finite Element Method (XFEM) model. Next, to verify the accuracy of provided application , a comparison is made with two other applications such as Artificial Neural Network-Jaya Algorithm (ANN-JAYA) and Artificial Neural Network-Particle Swarm Optimization (ANN-PSO). The results of the three algorithms show good convergence, with a slight increase in accuracy for ANN-E JAYA. MATLAB code and data used in this article can be found at https://github.com/Samir-Khatir/GFRP-ANN-E-JAYA.git.

Investigation of the effect of AWJ drilling parameters for delamination factor and surface roughness on GFRP composite material

PurposeThe purpose of this study is to optimize processing parameters to get the smallest average surface roughness (Ra) and delamination damage (Fd) values during drilling via abrasive water jet (AWJ) of the glass fiber-reinforced polymer composite material produced at [0°/90°]s fiber orientation angles.Design/methodology/approachDrilling experiments were done via AWJ with three-axis computer numerical control (CNC) control system. Machine processing parameters such as water pressure of 3,600, 4,300, 4,800 and 5,300 bar; stand-off distance of 1, 2, 3 and 4 mm; traverse rate of 750, 1,500, 2,000 and 3,000 mm/min; and hole diameters of 8, 10, 12 and 14 mm have been selected. The effects of processing parameters in drilling experiments were investigated in conformity with the Taguchi L16 orthogonal array and the data obtained were analyzed using Minitab 17 software. The signal/noise (S/N) ratio was taken as a basis for evaluating the test results. Optimum processing conditions were determined by calculating the S/N ratio for both Ra and Fd in conformity with the “smaller is better” approximation. The effects of processing parameters on Ra and Fd were statistically investigated using analysis of variance, S/N ratio and Taguchi-based gray relational analysis. Ra and Fd were predicted by evaluating with the ANN model and were predicted with the least amount of error.FindingsIt has been determined that the most effective parameter for Ra and Fd is the water pressure and then the stand-off distance.Originality/valueThe novel approach is to reduce cost and the time spent by using Taguchi optimization as a result of AWJ drilling the material in this fiber orientation [0°/90°]s.

Numerical Analysis of Unidirectional GFRP Composite Mechanical Response Subjected to Tension Load using Finite Element Method

Composite material is a well-known structural material which is increasingly adopted as an engineering structure material. Glass fiber reinforced polymer offers the lightweight and high strength characteristics that is required for the modern industry, such as aviation, automotive, wind power, and marine technology. One of the important mechanical characteristics of the composite materials are the tensile properties, because it is well known as the material strength. Therefore, the investigation of mechanical response on the glass fiber reinforced polymer (GFRP) tensile test using numerical analysis is important for the estimation of structural response of the GFRP complex structure, such as boat construction. The objective of this research is to assess and estimate the mechanical response of the GFRP composite material subjected to tension load using finite element method. The linear transversely isotropic model is developed to estimate the unidirectional glass fiber GFRP with the configuration of fiber orientation angles of 0°, 30°, 45°, 60° and 90°. The results show that FE simulation are capable to detect the specimen response during the tensile test. The maximum discrepancy of the estimated stress strain diagram is about 16.5% to 32% compared to experimental data. The larger orientation angle has shown the larger discrepancy value. It is found that the increment of discrepancy value is generated by the nonlinearity behavior of the material due to the domination of polymer material behavior on the large orientation angle. Otherwise, the FE models have estimated accurately the ultimate strength, maximum displacement and fracture load. It can be concluded that the linear transversely isotropic model is adequately accepted as the estimation method of the GFRP composite structure response.

Comparative Study of Damping on Pultruded GFRP and Steel Beams.

The use of glass fibre reinforced polymer (GFRP) composites in civil engineering structures has seen considerable growth in recent years due to their high strength, low self-weight, and corrosion resistance, namely when compared to traditional materials, such as steel and reinforced concrete. To enable the structural use of GFRP composite materials in civil engineering applications, especially in footbridges, it is necessary to gather knowledge on their structural behaviour, particularly under dynamic loads, and to evaluate the ability of current design tools to predict their response. In fact, excessive vibration has a major influence on the in-service performance (comfort) of slender structures as well on their service life. The use of composite materials that combine high damping capacity with relatively high stiffness and low mass can provide functional and economic benefits, especially for footbridges. This paper aims to investigate the dynamic behaviour of GFRP free-supported beams to evaluate their modal characteristics (frequency, damping, and modal shape). To assess the benefits of using a structure made of pultruded GFRP rather than a conventional material—steel, a comparative analysis between the dynamic characteristics of GFRP and steel beams is performed. To specifically address material damping and to minimize the interference of the boundary conditions, the beams are tested in a free condition, resting on a low-density foam base. The results show that the damping capacity of GFRP is much higher than that of steel, as the measured damping factor of GFRP is five times higher than that of steel for the same boundary conditions and similar geometry. Furthermore, the fact that the frequencies of the tested specimens resemble for the two different materials highlights the perceived damping qualities of the polymer-based composite material. Finally, an energy method for evaluating the influence of the scale factor on material damping is applied, which made it possible to infer that the damping varies as a function of frequency but is not explicitly affected by the length of the specimens.

MWCNTs doped GFRPs drilling: crosscheck among holes obtained by alternative manufacturing methods

In this study, the holes of glass fiber reinforced polymer (GFRP) and multi-walled carbon nanotubes (MWCNTs) doped GFRP composite materials were drilled using abrasive water jet (AWJ), CO2 laser cutting, orbital drilling, and punching methods; the effects of these methods on hole quality were determined. The hole entry and exit dimensions were obtained equal and in the desired size by orbital drilling; thus, kerf formation was prevented due to the lateral and face milling of the end mill. The surface hardness change was not observed in the hole circles obtained with the orbital drilling and punching methods. However, epoxy hardening was observed in the hole circles obtained by laser cutting due to the heat effect of laser beam. In AWJ method, matrix-fiber integrity was disrupted, and delamination was observed due to the effect of water pressure and kinetic energy; consequently an increase in material thickness was observed and surface hardness decreased. It was determined that MWCNTs additive increased the surface hardness of composites and maintained its hardness and durability in post-cutting measurements. Splintering and burring were not seen in any method, but fiber carbonization was observed in the inner parts of the hole due to thermal effects in laser cutting.

Study the effect of sputtering power on wettability properties of chromium oxide coated GFRP composite materials

Coatings of Chromium oxide were deposited on the substrate of GFRP (Glass Fibre Reinforced Polymer) composite using RF magnetron sputtering. GFRP composites exposed to different environmental condition raises new challenges toits wetting surface, so the main aim of this research work is to develop a coating on the surface of GFRP composite in super hydrophobic manner. Chromium Oxide Films were characterized by X-Ray Diffraction (XRD) analysis, Roughness tester and Ramehart Goniometer. Wettability of the GFRP composite have been studied and compared the coated and uncoated GFRP composite. In addition, Ramehart goniometer was used for determining contact angle. Contact angle values was observed 84° to 98.4° experimentally with the change in target power. The results shows that Chromium Oxide (Cr2O3) coatings displays hydrophobic nature with the rise of target power and the contact angle of 98.40 is achieved corresponding to 290 W power. The thin film exhibited hydrophobic nature with the increase in target power.

Influence of micro and nano carbon fillers on impact behavior of GFRP composite materials

Glass fiber-reinforced polymer (GFRP) composite with neat epoxy matrix and GFRP composite with epoxy-Micro carbon and epoxy-MWCNT composite matrix in were prepared. Micro and Nanofillers taken at 5,10,15 wt%(wt%) and 2,4,6 wt% respectively. The un-notched impact test is carried on each specimen as per ASTM D4812. The strength values are compared with neat epoxy matrix five layers of GFRP composite. The lack of a notch makes test method especially useful for reinforced materials where a notch may mask the effects of the notch. The impact response measured in terms of impact strength. Rest results showed that there is a significant impact of filler material on the strength. The size of particles is also showing a definite mark on the impact response. The 4 wt% Nano filler in Epoxy GFRP showed better results than all other samples. In micro fillers, 5 wt% of composition composite exhibited better strength. Overall, the research showed the potential to tailor composite properties to enhance impact performance by using different types, concentrations, and configurations of nano/microparticles.

Analysis of damage modes of glass fiber composites subjected to simulated lightning strike impulse voltage puncture and direct high voltage AC puncture

Understanding the damage mechanisms of fiber-reinforced polymer matrix composite materials under high voltage conditions is of great significance for lightning strike protection and high voltage insulation applications of composite structures. In this paper, we investigated effects of the lightning impulse (LI) voltage and high voltage alternating current (HVAC) puncture on damage modes of the electrically nonconductive glass fiber-reinforced polymer (GFRP) matrix composite materials through experimental tests and numerical simulations. The LI and HVAC tests represent the lightning strike and high voltage insulation cable puncture conditions, respectively. Our experimental examinations showed that GFRP composite specimens subjected to the LI voltage test exhibited distinct damage modes compared with those in the HVAC puncture test. The GFRP composite material suffered more charring and fiber vaporization in the HVAC puncture test, whereas less matrix charring and fiber vaporization but severe fiber breakage and delamination in response to the LI voltage tests. The findings indicate that the thermal effect dominates the damage of GFRP composites inflicted by the HVAC puncture test, whereas the mechanical impact effect governs the GFRP composite damage in the LI voltage test. In addition, the electric arc plasma formation during the puncture of the GFRP composite material was modeled through solving Maxwell’s equations and the heat generation equations using finite element analysis. Simulation results provided insights on the effects of duration and intensity of the high voltage electric discharge on the composite damage.

Strength Characteristics of Concrete Specimen Wrapped With Glass Fiber Reinforced Polymer

Glass Fiber Reinforced Polymer (GFRP) is one of a relatively new class of composite material. These materials are manufactured from a combination of fibers and resins. These composite materials have proven to be efficient and economical for the development of new structures and the repair of deteriorating structures in civil engineering. One of the important reasons for the use of GFRP composite materials is because of its superior mechanical properties. These mechanical properties includes impact resistance, strength, stiffness, flexibility and also its enhanced ability to carry loads. In construction industry, in order to meet the advanced infrastructure requirements, new innovative technologies and materials are being introduced. Also any new technology or material has its own limitations but to meet the new requirements, new technologies and materials have to be invented and put to use. With structures becoming old and increasing bar corrosion, old buildings have to be retrofitted with additional materials to increase their durability and life. For strengthening and retrofitting of concrete structures confinement with FRP has various applications. In this project concrete specimens are wrapped with glass fibre reinforced polymers to study the effect of confinement in the strength of specimens. For wrapping bi-directional and uni-directional glass fibre reinforced polymer mats are used. During the uni-directional glass fibre reinforced polymer wrapping, it is wrapped in both horizontal and vertical directions. The fiber used in this paper is bi-directional fibre. To find the effect of wrapping, specimens are wrapped in one rotation and two rotations.

Air-coupled ultrasonic testing to estimate internal defects in composite panels used for boats and luxury yachts

In constructions of boats and luxury yachts, Glass Fiber Reinforced Polymer (GFRP) composite materials are widely employed owing to their high mechanical performance, light weight and flexibility in manufacturing complex shapes. However, GFRP composite materials can be affected by several intrinsic defects (e.g. inclusion, delamination, resin excess or lack), because of both wrong production process and post-production handling. Although conventional ultrasonic testing is the most applied method to enhance the structural safety and quality, it presents a strong limitation in achieving an efficient contact between the transducers and the testing surfaces. Air-coupled ultrasonic testing can be used as a valid alternative, overcoming the previous disadvantage. Aim of this study is to demonstrate the ability of air-coupled ultrasonic testing (ACUT) for qualitatively and quantitatively evaluation of internal defects in GFRP composite panels as those typically used for boats and luxury yachts construction. Simulated delaminations of different sizes have been analysed as well as excess and lack of resin. Results highlighted that a good signal-to-noise ratio can be achieved for delamination greater than 15 mm with correct defect shape recovering, hence making ACUT an appropriate choice for the interactive engineering design and manufacturing of boats.

Mechanical and Fracture Properties of Steel/GFRP Hybrid Panels for an Improved Moveable Weir after Exposure to Accelerated Natural Environmental Conditions

This study evaluated the performance of a hybrid panel in an improved moveable weir after exposure to accelerated environmental climate conditions. When exposed to a river environment, corrosion problems on improved moveable weir steel panels can occur. To address this, a hybrid panel with structure layering glass fiber-reinforced polymer (GFRP) panels on both sides of the steel panel was used. The steel was, therefore, not exposed to the outside. However, this hybrid panel is a structure that uses a mixture of two materials with different properties and there is the possibility of performance degradation when the GFRP composite material, i.e., the structure that wraps around the bond interface, and the steel panel are exposed to a river environment. Thus, we evaluated the durability of the hybrid panels by repeated exposure to long-term high temperatures, dry–wet environmental cycling, long-term freezing, and freeze–thaw cycling in an accelerated climate deterioration environment. In the flexural tests, the surface processing of the steel panel was shown to be important, with sand-blasted test specimens showing higher flexural strength. For the control specimens, the flexural strength decreased as the thickness of the GFRP panels increased. However, for the sand-blasted specimens, the flexural strength increased as the thickness of the GFRP panels increased. After exposure to accelerated climate deterioration, the flexural strength tests showed that the residual strength increased with panel thickness and that the residual strengths were greater for specimens incorporating sand-blasted steel panels. The results of our testing show that hybrid panels incorporating sand-blasted steel were adequate for use in improved moveable weirs.

A review on machinability of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composite materials

Abstract Fiber reinforced polymer (FRP) composite materials are heterogeneous and anisotropic materials that do not exhibit plastic deformation. They have been used in a wide range of contemporary applications particularly in space and aviation, automotive, maritime and manufacturing of sports equipment. Carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composite materials, among other fiber reinforced materials, have been increasingly replacing conventional materials with their excellent strength and low specific weight properties. Their manufacturability in varying combinations with customized strength properties, also their high fatigue, toughness and high temperature wear and oxidation resistance capabilities render these materials an excellent choice in engineering applications. In the present review study, a literature survey was conducted on the machinability properties and related approaches for CFRP and GFRP composite materials. As in the machining of all anisotropic and heterogeneous materials, failure mechanisms were also reported in the machining of CFRP and GFRP materials with both conventional and modern manufacturing methods and the results of these studies were obtained by use of variance analysis (ANOVA), artificial neural networks (ANN) model, fuzzy inference system (FIS), harmony search (HS) algorithm, genetic algorithm (GA), Taguchi's optimization technique, multi-criteria optimization, analytical modeling, stress analysis, finite elements method (FEM), data analysis, and linear regression technique. Failure mechanisms and surface quality is discussed with the help of optical and scanning electron microscopy, and profilometry. ANOVA, GA, FEM, etc. are used to analyze and generate predictive models.

Investigation on the effect of drilling parameters on the tool wear and delamination of glass fibre-reinforced polymer composite using vibration signal analysis

Glass fibre-reinforced polymer composite materials are widely used in industrial, aerospace and automotive sector. It has excellent properties such as high strength to weight ratio, higher fatigue limit, high stiffness to weight ratio, corrosion resistance and design flexibility. The strength of the composite highly depends upon orientation of the fibre material. Drilling is one of the major machining operations that are carried out on Glass fibre-reinforced polymer composite materials to the need for components assembly. There are many problems encountered while drilling glass fibre-reinforced polymer composites. The major problems are excessive tool wear and delamination of the composite during drilling, which reduce the strength of the composite during application. In the present study, the experimental investigations are carried out to analyse the effect of various machining parameters, i.e. cutting speed and feed rate on the tool wear and delamination. The time and frequency domain analysis of vibration signals measured using sound sensor is also used to predict the effect of machining parameters on delamination as well as to develop the tool replacement strategy.

Experimental investigation of delamination and surface roughness in the drilling of GFRP composite material with different drills

This paper describes the experimental investigation in the drilling of glass fiber reinforced polymer (GFRP) composites with three dissimilar tools, having different materials and geometries (i.e. helical flute (HSS) drill, Carbide tipped straight shank (K20) drill, and Solid carbide eight-facet drill). Tool geometry and materials are considered to be major factor, which is responsible for drilling-induced damage. Cutting parameters also influence drilling-induced damage. These damages were measured by two delamination factors. Image processed technique was utilized to determine the damaged area and maximum damaged zone diameter. The results showed that qualities of drill holes significantly improved when solid carbide eight-facet drill was used.

Static and dynamic responses of Halgavor Footbridge using steel and FRP materials

In recent years, the use of fiber reinforced polymer composites has increased because of their unique features. They have been used widely in the aircraft and space industries, medical and sporting goods and automotive industries. Thanks to their beneficial and various advantages over traditional materials such as high strength, high rigidity, low weight, corrosion resistance, low maintenance cost, aesthetic appearance and easy demountable or moveable construction. In this paper, it is aimed to determine and compare the geometrically nonlinear static and dynamic analysis results of footbridges using steel and glass fiber reinforced polymer composite (GFRP) materials. For this purpose, Halgavor suspension footbridge is selected as numerical examples. The analyses are performed using three identical footbridges, first constructed from steel, second built only with GFRP material and third made of steel- GFRP material, under static and dynamic loadings using finite element method. In the finite element modeling and analyses, SAP2000 program is used. Geometric nonlinearities are taken into consideration in the analysis using P-Delta criterion. The numerical results have indicated that the responses of the three bridges are different and that the response values obtained for the GFRP composite bridge are quite less compared to the steel bridge. It is understood that GFRP material is more useful than the steel for the footbridges.

Mechanical damage assessment of Glass Fiber-Reinforced Polymer composites using passive infrared thermography

This study deals with characterization of the damage and thermomechanical behavior of the Glass Fiber-Reinforced Polymer composite materials (GFRP), submitted to static tensile loadings, using a passive infrared thermography technique. During mechanical testing, thermal measurements are performed by means of an IR camera. The thermal data post-processing involves the analysis of both the thermal maps and the thermomechanical behavior of the material. The thermal maps analysis allows qualitative evaluation of the created material damage at high stress levels. While the thermomechanical analysis gave us a quantitative evaluation of the material damage, for both low and high stress levels, through definition of a new thermoelastic damage variable.

Improvement of the piezoelectric properties of glass fiber-reinforced epoxy composites by poling treatment

Recently, a new non-destructive method has been proposed for damage monitoring of glass fiber-reinforced polymer composite materials using the piezoelectric characteristics of a polymeric matrix. Several studies of the piezoelectric properties of unidirectional glass fiber epoxy composites and damage monitoring of double-cantilever beams have supported the claim that the piezoelectric method is feasible and powerful enough to monitor the damage of glass fiber epoxy composites. Generally, conventional piezoelectric materials have higher piezoelectric characteristics through poling treatment. In this work, we investigated the change of the piezoelectric properties of glass fiber-reinforced epoxy composites before and after poling treatment. The piezoelectric constants (d33) of glass fiber-reinforced epoxy composites increased by more than 400%. Also, x-ray diffraction tests revealed that poling treatment changed the degree of crystallinity of the epoxy matrix, and this led to the improvement of the piezoelectric characteristics of glass fiber-reinforced epoxy composites.