GFRP Composites Research Articles

Study of the Mechanical Properties of Polyester Based GFRP Composites in E-Waste from Mobile Phones Displays

Everyone now lives in a technologically highly hybridised environment; mobile technology is regarded as one of the most significant of all technologies. Inside the phone is the entire world. This article primarily focuses on recycling e-waste into composites (especially waste from mobile phones). The range of products used for this study included basic and smartphones. The primary product chosen was the display glass from smartphones. With the use of recent literature reviews, the problem was identified. Many studies focused on polyester resins with ceramic powders and their composites. The mobile display powder has been mixed with Polyester resin. The mobile phone display electronic waste (MPDEW), like polyester resin, was cost-effective. Mobile phone waste was used as filler in various proportions including 0, 5 and 10 %. To determine the effect of e-waste with polymer composites, the mechanical properties such as tensile, compression, flexural, and impact were undertaken. The scanning electron microscope was also used for the microstructural analysis.

Analysis of surface roughness, temperature, short aging, and residual notched and bearing strengths in supported drilling of thin GFRP composites

This study aimed to analysis open‐hole tensile strength, pin-bearing strength, cutting temperature, and surface roughness of drilled thin glass fiber reinforced polymer composites. The specimens were clamped from both sides during drilling operations. The cutting temperature was measured using high resolution infrared camera. Surface roughness was evaluated by seven parameters to identify the most suitable ones. Multiple regression models were developed to predict critical thrust force (CTF), critical feed, and cutting temperature in drilling operations. The measurements indicate that the cutting temperature is higher than the matrix's glass transition temperature and hence, the surface roughness paramaters Ra, Rq and Ry are increased at the maximum cutting conditions by 57%, 51%, and 36% respectively. In contrast, the bearing strength improved by 13%. This peculiar phenomenon was deeply analyzed with the aid of short ageing effects on the post curing, which increase the crosslinking density within the composites and improve the matrix's capacity to efficiently transmit the loads to the reinforcing fibers. For the first time, the optimum cutting conditions were determined based on the optimum short ageing parameters (temperature and time). Supported drilling increases CTF by 23%, which can reduce machining time and manufacturing costs with fewer delamination concerns.

Three-point bending damage detection of GFRP composites doped with graphene oxide by acoustic emission technology

The incorporation of graphene oxide (GO) into composite materials can modulate their overall performance. To enhance the performance of acoustic emission (AE) signals, 3% GO was incorporated into glass fiber-reinforced polymer (GFRP) composites, resulting in the creation of GO-GFRP composite materials. The sentry function was first used to investigate the damage evolution of the material. Then, the AE signals were analyzed using multivariate mode decomposition (MVMD) and the generalized S transform to identify the damage mechanisms. Finally, scanning electron microscopy (SEM) was used to observe the fracture surfaces of the samples to confirm the material failure. The experiments identified four damage mechanisms: matrix cracking, fiber debonding, delamination failure, and fiber breakage. It was also found that GO-GFRP composites are more prone to fiber debonding compared to GFRP composites without added GO.

Enhanced extreme temperature bending and delamination resistance of GFRP composites through z-directional aligned nano-reinforcement: Emphasizing the effects of CNT functionalization

Laminated FRP composites' weak out-of-plane mechanical performance prevents their usage in structural applications where homogeneous load bearing qualities are required. In this regard, a z-directional nano-reinforcement approach was implemented to mitigate the poor in-plane shear and out-of-plane response of laminated glass fiber epoxy (GE) composites under extreme in-service temperature conditions. CNT and functionalized CNT (FCNT) were dispersed separately in the GE composites' epoxy matrix and subjected to a z-direction electric field alignment treatment. Flexural and short beam shear tests of GE composites with random and aligned CNT/FCNT were performed at room temperature, in-situ cryogenic and elevated temperature conditions (RT, CT and ET, respectively). GE composite with aligned FCNT (A-FCNT-GE) consistently outperformed other composites at all considered temperatures with remarkable improvements, specifically ∼39%, ∼41% and ∼47% in flexural strength, and ∼30%, ∼30%, and ∼24% in interlaminar shear strength (ILSS) over the control GE composite at RT, CT and ET, respectively. Dynamic mechanical thermal analysis suggested that the synergetic impact of functionalization and alignment of FCNT improved the viscoelastic properties of the A-FCNT-GE composite across a range of temperature conditions. Fractography analysis provided insight into the interfacial and interlayer mechanisms that improved the extreme temperature condition mechanical performance. The reliability of electric field aligned FCNT as a z-directional nano-reinforcement in laminated composites at extreme temperature conditions was established in this study.

An analytical closed-form solution for the in-plane elastic modulus of plain-woven textile composites

Engineering application of textile composites needs simple relations for the estimation of their mechanical properties. Many homogenization and simplified models have been already proposed for the analytical characterization of the elastic moduli of this class of materials. Along this route, the current study introduces an analytical solution for the longitudinal elastic modulus of plain-woven textile composites. A hybrid beam-spring model of the representative unit cell (RUC) is postulated consisting of a horizontal beam connected to an inclined beam, two supporting springs beneath the free end of the horizontal beam and the common end of the horizontal and inclined beams, and a torsion spring at the free end of the inclined beam. The mechanical and geometrical properties of the beams and springs are calculated from the weave structure and the symmetry conditions. A reduction technique from the matrix analysis of structures is borrowed to consider the effect of internal degrees of freedom on the in-plane stiffness coefficient and a closed-form formula is extracted for the elastic modulus. The proposed analytical formula is finally verified against available experimental data and a wide range of FE predictions for the GFRP and CFRP plain-woven composites.

Seawater's impact on the mechanical properties of SiO2 and TiO2 fillers in glass reinforced epoxy composites

The purpose of this study is to investigate the mechanical characteristics and moisture absorption of GFRP composites with filler materials. The specimens are created in accordance with ASTM standards ASTM D3039 and ASTM D790 for the tensile and flexural tests, respectively. These samples were dipped in seawater for 48 days after manufacturing to assess their moisture absorption. Mechanical properties of dry and aged specimens are examined based on ASTM standards using a universal testing machine. The findings revealed that the moisture absorption is more for type B tensile glass/epoxy specimen. In comparison to the filled specimen, the unfilled (glass/epoxy type A tensile) specimen absorbed less water. The type C tensile and flexural glass/epoxy specimen absorbed a moderate amount of water. After analyzing the glass/epoxy with and without filled specimens the drop in flexural characteristics and tensile characteristics of type B glass/epoxy specimen is lesser compared with the other modification of glass/epoxy specimen.

Mechanical, tribological, and surface morphological studies on the effects of hybrid ilmenite and silicon dioxide fillers on glass fibre reinforced epoxy composites

Recently, researchers have been attempting to enhance the mechanical and tribological characteristics of thermosetting epoxy composites by incorporating inorganic nanoparticles and ensuring their uniform distribution throughout the matrix. This study characterises ball-milled ilmenite (FeTiO3-size of 63 nm) and silicon dioxide (SiO2-size of 67.5 nm) fillers added to epoxy in proportions of 0:0, 2.5:2.5, 5:5, and 7.5:7.5% by weight. A liquid ultrasonic technique is used to blend the fillers with the epoxy, and compression moulding is used to fabricate the composite. Mechanical tests were performed based on ASTM standards. Tensile strength, tensile modulus, flexural strength, flexural modulus and elongations at break(tensile and flexural test) of 5:5 wt % are 30.54%, 12.2%, 32.22%, 28.98%,23.78% and 23.53% higher than neat sample respectively. Shore "D" hardness and Izod's impact strength are 4.65% and 98.93% higher at 5:5 wt % than neat sample respectively. Specific wear rate decreased from 2.6 × 10−11 m3/Nm (neat GFRP: 0 wt % glass fibre reinforced polymer composite) to 0.7 × 10−11 m3/Nm at 5:5 wt % filler. Nanoparticles lowered the coefficient of friction by around 16.66%, 60.42%, and 33.33% at sliding distances of 100 m for 2.5:2.5, 5:5, and 7.5:7.5 wt % respectively with the neat sample. A 5:5 wt percent resulted in 76.68% less wear volume loss than pure GFRP. Field emission scanning electron microscopy (FESEM) analysis revealed element distributions, particle size, pullout of fibers, damaged interfaces, filler dispersion, voids, wear debris, interfacial debonding, and cavities. Thus, this approach enhances GFRP composite's mechanical, tribological, and structural properties.

Effect of Hybridization of Ramie Fibers on the Vibrational and Damping Responses of Ramie/Glass/Epoxy Resin Composite Laminates

Fiber reinforced polymer composites made with glass fibers are among the oldest and most popular kinds of composites in use today. Glass fiber reinforced composites' key benefits are their adaptability for specific material applications, which allows them to give a number of design advantages relating to strength, chemical stability, impact damage tolerance, heat insulation, and low cost. The focus of this research is to investigate the role of hybridized ramie fibers in the assessment of enhanced vibrational damping capabilities in fiber glass reinforced composites, as well as in the initial assessment to verify their acceptability for real-time applications. Composite molding employing the hand layup technique was used to fabricate hybrid epoxy composites with ramie to glass fiber weight ratios from 0 to 50%. A free vibration test was performed to determine the hybrid composite's vibration dampening capabilities as a function of the ramie fiber filler content. The results demonstrated that the damping ratio was reduced when the percentage of ramie fiber in the GFRP composite was raised from 10% weight to about 50% weight. But adding up to 40% wt of ramie fiber to the hybrid composite had the biggest effect on the damping ratio, natural frequency, storage modulus, and loss modulus. This means that using ramie fiber in hybrid composites will be cost-effective and good for the environment.

Ultrasonic Inspection for aging monitoring of GFRP composites

The use of composite materials has been an option increasingly used in various industry sectors. However, the degradation process by which these materials are subjected due to operational conditions is a reality that makes monitoring a challenge. In this work, conventional ultrasonic technique was used to analyse the behaviour of GFRP pipes under different aging conditions (temperature and pressure). The pipes were submitted to aging for 2, 6 and 18 months and acoustic measurements were performed in certain areas of each pipe in order to monitor the relevant locations, both in circumference and in length. The gathering of these signals was carried out periodically throughout the aging process. Through the methodology presented in this work regarding ultrasonic inspection, it was possible to correlate the acoustic properties obtained with the mechanical properties of the material during aging. Additionally, after the end of the aging process and occasional failures, some samples were extracted to perform tensile tests, which were able to indicate residual Young Modulus in the axial direction. Sound testing for mechanical characterization were also performed and their results were compared to the ones calculated by ultrasonic results. Microstructure of the material and its manufacturing process were also found to be important parameters that must be considered. The experimental database obtained were analysed using statistical tools to evaluate the feasibility of a trend model in the behaviour of material properties during aging.

3D Finite Element investigation in high speed drilling of unidirectional Glass Fiber Reinforced Polymer composite

The unidirectional Glass Fiber Reinforced Polymers (UD-GFRP) composites have wide spread usage in the current modern industries, because of their significant mechanical behavior over conventional materials and metals. Drilling operation is a vital machining process of making holes with high precision during the pre-assembly process of the laminates. Hole with higher precision is needed to guarantee the strength of the joint made during the assembly process. However, the effect of key drilling parameter settings like cutting speed, tool diameter, tool geometry, drill material and feed rate is more significant in achieving acceptable dimensional tolerance and quality holes. The effect of the thrust forces in the quality of the hole and chip morphology is very high especially during the high speed drilling process. Hence, the prediction and investigation of the critical thrust force is very much needed to reduce the machining induced defects and thereby improving the effectiveness of the drilling process. In this research work, the prevalidated 3D Finite Element Model (3D FEM) developed in ABAQUS/Explicit software is utilized to analyze and explore the complex cutting mechanics behind high speed drilling of GFRP composite. The effect of machining parameters settings on thrust forces are predicted and reported using 3D FE analysis.

Ultrasonic Welding of Surface Pretreated GFRP Composites Using PMMA Interlayer with Addition of Nanoparticles

Ultrasonic Welding of Surface Pretreated GFRP Composites Using PMMA Interlayer with Addition of Nanoparticles

A Comparison of Vacuum Infusion, Vacuum Bagging, and Hand Lay-Up Process on The Compressive and Shear Properties of GFRP Materials

Fiber-reinforced plastics are widely used in aerospace, marine, military, automotive, wind turbine, sports, and civil engineering applications. GFRP is a common material used in engineering applications such as for UAV structural material. Several techniques that can be used in the composite structure manufacturing process are HLU, VB, and, VARI. This paper studies the influence of the three manufacturing processes on the compressive and shear properties of GFRP composites. This study uses e-glass fiber as reinforcement material and a clear epoxy polymer called lycal as matrix material. The composites were manufactured by using HLU, VB, and VARI processes. The specimen dimensions, compressive, and shear tests are following ASTM standards. The microstructural characteristics were observed using a scanning electron microscope. The compressive strength of VARI composite is higher than HLU and VB composites up to 71% and 53%, respectively. The shear strength of the VARI composite is higher than HLU and VB composites up to 71% and 53%, respectively.

Tribo-Mechanical Investigation of Glass Fiber Reinforced Polymer Composites under Dry Conditions.

Tribo-mechanical experiments were performed on Glass Fiber Reinforced Polymer (GRFP) composites against different engineering materials, and the tribological behavior of these materials under dry conditions was investigated. The novelty of this study consists of the investigation of the tribomechanical properties of a customized GFRP/epoxy composite, different from those identified in the literature. The investigated material in the work is composed of 270 g/m2 fiberglass twill fabric/epoxy matrix. It was manufactured by the vacuum bag method and autoclave curing procedure. The goal was to define the tribo-mechanical characteristics of a 68.5% weight fraction ratio (wf) of GFRP composites in relation to the different categories of plastic materials, alloyed steel, and technical ceramics. The properties of the material, including ultimate tensile strength, Young's modulus of elasticity, elastic strain, and impact strength of the GFPR, were determined through standard tests. The friction coefficients were obtained using a modified pin-on-disc tribometer using sliding speeds ranging from 0.1 to 0.36 m s-1, load 20 N, and different counter face balls from Polytetrafluoroethylene (PTFE), Polyamide (Torlon), 52,100 Chrome Alloy Steel, 440 Stainless Steel, and Ceramic Al2O3, with 12.7 mm in diameter, in dry conditions. These are commonly used as ball and roller bearings in industry and for a variety of automotive applications. To evaluate the wear mechanisms, the worm surfaces were examined and investigated by a Nano Focus-Optical 3D Microscopy, which uses cutting-edge μsurf technology to provide highly accurate 3D measurements of surfaces. The obtained results constitute an important database for the tribo-mechanical behavior of this engineering GFRP composite material.

Analysis of mechanical performance and energy consumption of microwave cured GFRP composites: A low-energy footprint manufacturing process

Analysis of mechanical performance and energy consumption of microwave cured GFRP composites: A low-energy footprint manufacturing process

A new methodology to predict the sequence of GFRP layers using machine learning and JAYA algorithm

In this paper, the best stacking sequence using experimental tests of GFRP composites is investigated. The main objective of this work is to determine the main specification of GFRP composite material, which is represented by its physics-mechanical properties, weight, and cost, before performing a series of experimental tests based on various stacking sequences. Our methodology is divided into three stages. The first stage is characterized by extracting the bending data from mechanical tests of some GFRP composites. In the second stage, the validated numerical model is used to simulate numerous cases of stacking sequences. In the last stage, the extracted data is used to determine the parameters for different stacking sequences using an inverse technique based on ANN and JAYA algorithm. The results provide a good prediction of parameters as well as a good orientation to make decisions on the best GFRP stacking sequence to be used, according to the required specifications of the manufacturer. The experemental data analysis can be found at https://github.com/Samir-Khatir/Sequence-GFRP

High-strain-rate Response of GFRP Composites Impregnated with Multiwalled Carbon Nanotube Reinforced Shear Thickening Fluid

High-strain-rate Response of GFRP Composites Impregnated with Multiwalled Carbon Nanotube Reinforced Shear Thickening Fluid

Simultaneous enhancement in interlaminar– shear strength and fracture toughness through nano Al2O3 dispersion in glass fiber/IPN multiscale composites

Simultaneous implementation of two polymer hybridisation routes, namely, interpenetrating polymer network (IPN) formation and nanofiller (nano Al2O3) addition, resulted in considerable increments in the mechanical performance of GFRP composites. Improvements of ∼18%, ∼8%, ∼14%, ∼19 %, and ∼29% in flexural strength, tensile strength, interlaminar shear strength (ILSS), critical strain energy release rate (GIC) during mode-I interlaminar fracture toughness (ILFT), and GIIC during mode-II ILFT values of nano-Al2O3 modified composites, respectively, were observed over composite without nano Al2O3. Composite with 0.1 wt.% of nano Al2O3 showed the highest mechanical properties in all the modes of testing except for mode-II ILFT testing, where composite with 0.4 wt.% of nano Al2O3 showed the highest toughness value. The synergy between the constituents and the thermal stability of the composites were analyzed via Fourier transform infrared spectroscopy and differential scanning calorimetry, respectively. Fractography was performed to understand the composites' failure criteria and toughening mechanisms.

Calibration and validation of a 3D homogenised model to simulate the damage progression of pultruded GFRP composites

A damage progression failure model for tridimensional finite element (FE) analyses has recently been proposed, allowing the simulation of composites as homogenized materials, greatly reducing computational costs. It is able to predict the damage and post-failure behaviour of composites, while its calibration can be performed with data derived from the standardized experimental characterization of the composite materials. This paper presents the calibration of that model for 5 new glass-FRP pultruded profiles, followed by the simulation of different application/design cases: (i) wide compact tension; (ii) compact compression; (iii) web-crippling; and (iv) bolted double-lap connection tests. While the results show that further investigation is needed to address the experimental characterization of the in-plane shear properties and the numerical simulation of bearing failure, overall the models were well able to predict the experimental strength, post-failure behaviour, failure modes and damage patterns, showing that the feasibility of using this damage progression model as a design tool.

Behavior of confined concrete with recycled glass fiber-reinforced polymer needles as coarse aggregates under axial compression

Cutting waste GFRP into needles as part of coarse aggregates in concrete shows to be a promising approach for recycling the waste GFRP composites. However, the resulting concrete has its compressive strength lower than that of normal concrete, and is therefore limited for use in nonstructural elements. The present study proposes a method to improve the robustness of such concrete in structural elements by utilizing the confined concrete concept, in which the concrete with GFRP needles is confined with carbon fiber-reinforced polymer wraps. A series of compression tests under concentric loading were conducted with the ratio of GFRP needles to the total coarse aggregates (i.e., replacement ratio) and the confining jacket stiffness as the two test parameters. The test results indicate that the compressive strength of unconfined concrete decreased by approximately 10% due to replacing 15% coarse aggregates with GFRP needles, while the confining jackets of the same stiffness applied resulted the compressive performance of the confined concrete with needles comparable to or even slightly higher than that of its counterpart without needles. Two widely-used theoretical models were used to predict the compressive performance of the confined concrete, finding that both of them overestimated the axial stress but underestimated the axial strain of the confined concrete with GFRP needles. Therefore, a refined model is required to predict the behavior of confined concrete with GFRP needles under axial compression.

Theoretical analysis on flexural strengthening of RC beams using GFRP composites in terms of strength to the weight ratio: A way forward

Aramid, Glass or Carbon Fibre Reinforced Polymer (GFRP/CFRP) are three types of composites that are commonly used in the civil, mechanical and automobile sectors worldwide. GFRP composites are often used for structural member strengthening, repairs, and rehabilitation. In comparison to CFRP and Aramid FRP composites, GFRP is easily available, inexpensive, good strength to the weight ratio, and has several additional benefits. The strength-to-weight ratio of GFRP composites and steel plates for flexural strengthening of RC beams is investigated in this work. Theoretical analysis for the RC beam strengthened with GFRP composites and steel plates were performed using the established equation based on Indian standards and the ACI code. The self-weight of the beam and the superimposed dead load owing to the block/brick work were taken into account in the design calculations. The beam's load carrying capability is inadequate due to the excessive load, thus it must be strengthened with different materials: GFRP Chopped Strand Mat (CSM) composites or steel plates. The evaluations were conducted under the assumptions that the loss of moment carrying capacity due to concrete deformation caused by bolt holes and failure due to GFRP composite delamination would be disregarded. Strength to weight ratio of GFRP composites and steel plate requirements have been computed and compared for the known dimensions, unit weight and tensile strength of the strengthening materials, and load carrying capability of the strengthened RC beam. Comparative study proves that the flexural strengthening of RC beams using GFRP composites, the strength to weight ratio is much higher than when the identical beams are strengthened with steel plate.