Glass-epoxy Composites Research Articles

Mechanical Response of Glass-Epoxy Composites with Graphene Oxide Nanoparticles.

Graphene-based fillers possess exceptional properties that encourage researchers toward their incorporation in glass-epoxy (GE) polymer composites. Regarding the mechanical and wear properties of glass-epoxy composites, the effect of graphene oxide (GO) reinforced in glass-epoxy was examined. A decrease in tensile modulus and increase in tensile strength was reported for 1 wt. % of GO. A shift in glass transition temperature Tg was observed with the addition of GO. The cross-link density and storage modulus of the composite decreased with the addition of GO. The decrease in dissipation energy and wear rate was reported with the increase in GO concentration. A simple one-dimensional damage model of nonlinear nature was developed to capture the stress-strain behavior of the unfilled and filled glass-epoxy composite. Tensile modulus E, Weibull scale parameter σo, and Weibull shape parameter β were considered to develop the model. Finally, to understand the failure mechanisms in GO-filled composites, a scanning electron microscopic (SEM) examination was carried out for tensile fractured composites.

Evaluation of Tensile and Flexural Properties of Unidirectional Glass-Epoxy Laminate with Aluminium Oxide and Magnesium Hydroxide as Filler Materials

Low weight is one of the most important factors in the design process of road and flight vehicles. The design engineers are careful with regards to the weight decrease without thinking twice about the primary strength. The composite is a lightweight material that has decent underlying properties and it is generally utilized. Fiber-supported polymer composites assumed a prevailing part for quite a while in an assortment of uses for their high explicit strength. The current work portrays the turn of events and the portrayal of another arrangement of GFRP. Experiments are carried out to study the effect of the addition of fillers by varying their percentages. The present work focus on the effect of the fillers on properties of Glass fiber epoxy laminates with aluminum oxide and magnesium hydroxide powders as the fillers. In the present work, fabrication and experimental investigation on unidirectional glass epoxy composites are carried out. Initially, glass fiber reinforced polymer laminate fabricated without filler material, hand layup followed by vacuum bagging methods are used . Then, by adding Aluminium oxide and Magnesium hydroxide as a filler material with different percentages like 5%, 10%, and 15% by weights and laminates are fabricated and experimental investigation is conducted to study their mechanical behavior. The comparative studies on the laminates are carried out and the obtained results are analyzed and those are quite interesting.

On the Residual Stresses and Fracture Toughness of Glass/Carbon Epoxy Composites.

The resistance to delamination in polymer composite depends on their constituents, manufacturing process, environmental factors, specimen geometry, and loading conditions. The manufacturing of laminated composites is usually carried out at an elevated temperature, which induces thermal stresses in composites mainly due to a mismatch in the coefficient of thermal expansion (CTE) of fiber and matrix. This work aims to investigate the effect of these process-induced stresses on mode-I interlaminar fracture toughness (GI) of Glass-Carbon-Epoxy (GCE) and Glass-Epoxy (GE) composites. These composites are prepared using a manual layup technique and cured under room temperature, followed by post-curing using different curing conditions. Double cantilever beam (DCB) specimens were used to determine GI experimentally. The slitting technique was used to estimate residual stresses (longitudinal and transverse direction of crack growth) inherited in cured composites and the impact of these stresses on GI was investigated. Delaminated surfaces of composites were examined using a scanning electron microscopy (SEM) to investigate the effect of post-curing on the mode-I failure mechanism. It was found that GI of both GE and GEC composites are sensitive to the state of residual stress in the laminas. The increase in the GI of laminates can also be attributed to an increase in matrix deformation and fiber–matrix interfacial bond with the increase in post-curing temperature.

The effect of fiber orientation and stacking sequence on carbon/E‐glass/epoxy intraply hybrid composites under dynamic loading conditions

AbstractThis study investigated the dynamic mechanical properties of hybrid intraply carbon/E‐glass epoxy composites with different orientations and stacking sequences under different loading conditions with increasing temperature. A neat epoxy and five various hybrid composites such as Carbon (0°)/E‐glass (90°), Carbon (45°)/E‐glass (135°), Carbon (90°)/E‐glass (0°), Carbon/E‐glass (alternating layer), and Carbon/E‐glass (alternating layer 45°) were manufactured. Three‐point bending test and dynamic mechanical test were conducted to understand the flexural modulus and viscoelastic behavior (storage modulus, loss modulus, and loss tangent) of the composites. Dynamic mechanical test was performed with the dual cantilever method, at four different frequencies (1, 5, 10, and 20 Hz) and temperatures ranging from 30 to 150°C. The experimental results of storage modulus, loss modulus, and loss tangents were compared with the theoretical findings of neat epoxy and various hybrid composites. The glass transition temperature (Tg) increased with the increase in frequency. A linear fit of the natural log of frequency to the inverse of absolute temperature was plotted in the activation energy estimation. The interphase damping (tanδi) between plies and the strength indicator (Si) of the hybrid composites were estimated. It was observed that the neat epoxy had more insufficient storage and loss modulus and a high loss tangent at all the frequencies whereas hybrid composites had high storage and loss modulus and a low loss tangent for all the frequencies. Compared with other hybrid composites, Carbon (90°)/E‐glass (0°) had higher strength and activation energy. The result of reinforcement of hybrid fiber in neat epoxy significantly increases the material's strength and stability at higher temperatures whereas decreasing free molecular movement.

Thermomechanical evaluation of a glass-epoxy composite for astronomical optical devices

Abstract Astronomical devices, such as optical benches, carry high precision instrumentation work at low temperatures (−150 °C). To fulfill engineering requirements, glass-epoxy composite trusses are proposed. To evaluate the performance of this solution, thermomechanical characterization is carried out by means of dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), flammability tests, and tensile test and Scanning Electron Microscopy (SEM) observations. Two family of coupons are tested; first one environmentally aged for 10 years and second one recently fabricated, both at 20, 0 and −20 °C. Ageing influence is more noticeable on thermal behavior as Tg and self-extinguish capacity are lower. Ultimate tensile strength and maximum strain are lower for the aged coupons (16–25%), but there is not a remarkable difference in terms of stiffness. Also, coupons mechanically tested at −20 °C show a slight increment in strength. These results show that ageing of glass-epoxy composites must be considered when high performance devices are conceived to be fabricated with.

Analysis and Optimization of Composite Propeller Shaft for Automotive Applications

In the field of automotive engineering polymeric composites played vital role due to its outstanding properties such as high strength, low weight and high stiffness. The purpose of this research is to develop a single piece steel (Cr–Mo SCM440) drive shaft using computer aided modelling tool and finite element method was used for analysing static analysing and free vibration. These results were compared with the propeller shaft made by carbon and glass epoxy composites. ANSYS software is used for accomplish total deflection, natural frequency, and modal analyses. From this work it was noted that the propeller shaft made using carbon epoxy offered better results as compared with steel and glass epoxy composite propeller.

Fatigue behaviour and damage mechanisms under strain controlled cycling: Comparison of Flax–epoxy and Glass–epoxy composites

Recent research showed that strain-controlled (constant strain-amplitude) cycling may be ideal for natural-fibre-composite (NFC) fatigue testing, since enforcing constant strain-rates eliminate the apparent modulus ‘improvement’ reported by several stress-controlled studies. This article re-examines Flax-reinforcement as an alternative to Glass by fatigue testing under constant strain-amplitude. Two Glass–epoxy crossply configurations ([0/90]3S, [±45]3S) are tested alongside four commonly-studied Flax–epoxy layups ([0]16, [0/90]4S, [±45]4S, quasi-isotropic [0/45/90/-45]2S). Fatigue endurance plots for all layups are modelled by linearised logarithmic strain-life relationships, for which unique parameters are identified. Evolution of several mechanical phenomena (stiffness damage, inelasticity, peak-stress) are evaluated as potential indicators of progressive damage, correlated with SEM-observed microstructure cracking. Flax–epoxy specimens have superior resistance to stiffness loss, lower inelastic strains , and withstand higher stresses per-unit-density, when compared to similar Glass-specimens. Flax remains a promising alternative to Glass for mechanical reinforcement against fatigue degradation in engineering structures.

Machine learning based thermal imaging damage detection in glass-epoxy composite materials

Machine learning (ML) based fatigue damage detection from thermal imaging in glass-epoxy composites is an important component of remote structural health monitoring used for safety assessment and optimization of composite structures and components. However, accurate characterization of fatigue damage hotspots in terms of size, shape, location, hysteretic heat, and local temperature deep inside the material using surface thermal images remains a challenge to date. This work aims at evaluating the theoretical accuracy level of hotspot characterization by training a ML model with artificially generated thermal images from 3D finite element models with increasing complexity. Modelling the fatigue damage as an intrinsic heat source allowed to significantly reduce the influence of thermal image noise and other uncertainties related to heat transfer. It is shown that ML can indeed accurately recover the heat influx, depth, and geometry of the heat source from the original thermal images of the composite materials with prediction accuracies in the range 85%–99%. The effect of training set size and image resolution on the prediction error is also presented. The findings reported in this work contribute to the advancement of accurate and efficient remote fatigue damage detection methods for fibre composite materials.

Impact damage to fibre metal laminates under compression loading

The effect of in-plane compression loading on the low energy impact response of fibre metal laminates (FML) is investigated. A GLARE®-like FML consisting of bonded layers of aluminium alloy and glass-epoxy composite was impacted at different incident energy levels (up to ∼20 J) while under different axial compression strain levels (up to 8000 μe). Experimental testing and finite element (FE) analysis reveal that compression preloading increases (up to 50%) the maximum impact force experienced by the FML due to shortening of the impact contact time. The out-of-plane deformation of the FML, the amount of plasticity damage to the aluminium layers, and the shape and size of delamination damage to the glass-epoxy layer are dependent on the compression strain level. The FE model predicted the impact response and impact damage to the FML. The FE model is a validated numerical tool to analyse the low energy impact response of FMLs used in compression load-bearing structures.

Tribological behaviour of SiC and AL2O3 filled glass-epoxy composite

Metal glass fibre reinforced composites which are considered as advanced composite materials play a significant role in aerospace, marine and automotive industries. In the current study, an attempt has been made to examine the tribological characteristics of glass fibre reinforced plastic (GFRP) composite filled with aluminium oxide (Al2O3) and silicon carbide (SiC) powder particles. Experiments were performed on pin-on-disc tribometer to evaluate the friction and wear rate as a function of normal load and sliding velocity under different conditions. For each composition of glass-epoxy composite filled with and without fillers, sliding tests were performed with normal load (20 N, 40 N, 60 N, 80 N 100 N) and sliding velocity (2.62 m/s, 4.18 m/s, 5.23 m/s, 6.85 m/s, 7.85 m/s) respectively. The metal GFRP composites were fabricated using hand-lay-up technique. The filler content (SiC & Al2O3) in epoxy-glass composite were varied. SiC was varied from 0 to 10% while Al2O3 was kept constant at 5%. To study the worn surface of glass-epoxy composite material scanning electronic microscopy is used. Before and after the experiment, weights of the composites (pin specimens) were studied on digital balance for wear loss. The present studies reported that the fabricated metal epoxy-fibre composite has performed excellent wear resistance when compared with epoxy-fibre composite without metal powders. The present work findings offer new insights into reinforcement in epoxy-glass composites with metal powders.

3D Woven Textile Structural Polymer Composites: Effect of Resin Processing Parameters on Mechanical Performance.

This work presents the manufacture of polymer composites using 3D woven structures (orthogonal, angle interlock and warp interlock) with glass multifilament tows and epoxy as the resin. The mechanical properties were analyzed by varying the processing parameters, namely, add-on percentage, amount of hardener, curing time, curing temperature and molding pressure, at four different levels during the composite fabrication for three different 3D woven structures. The mechanical properties of composites are affected by resin infusion or resin impregnation. Resin infusion depends on many processing conditions (temperature, pressure, viscosity and molding time), the structure of the reinforcement and the compatibility of the resin with the reinforcement. The samples were tested for tensile strength, tensile modulus, impact resistance and flexural strength. Optimal process parameters were identified for different 3D-woven-structure-based composites for obtaining optimal results for tensile strength, tensile modulus, impact resistance and flexural strength. The tensile strength, elongation at break and tensile modulus were found to be at a maximum for the angle interlock structure among the various 3D woven composites. A composition of 55% matrix (including 12% of hardener added) and 45% fiber were found to be optimal for the tensile and impact performance of 3D woven glass–epoxy composites. A curing temperature of about 140 °C seemed to be optimal for glass–epoxy composites. Increasing the molding pressure up to 12 bar helped with better penetration of the resin, resulting in higher tensile strength, modulus and impact performance. The optimal conditions for the best flexural performance in 3D woven glass–epoxy composites were 12% hardener, 140 °C curing temperature, 900 s curing time and 12 bar molding pressure.

Effects of stacking sequences and longitudinal parameter on the dynamic characteristics of multilayer glass epoxy composite

In the current scenario, the structures made of composites are drawing attention due to their high spring rate, capacity to withstand high force, reinforcement and optimized mass. Up till now, several materials have been designed and manufactured. The components as well as structures made of these composite materials do expose to dynamic loading during their functions which leads to the failure of the respective component/structure. The dynamic characteristics depend on the material properties, physical dimension, no. of layers, orientation of the fibers and end conditions. Here an analysis is performed to determine the vibration characteristics of multilayer composite beams made of glass epoxy composite. The Cantilever boundary condition is considered. Ten layers are considered. Various stacking are considered with the different fiber orientations. The natural frequency of a multilayer composite beam is sensitive to the length and fiber orientations. As the length and number of layer increase, the natural frequency decreases. The natural frequency for fiber orientation at 900 is minimum as compared to other fiber orientations irrespective of the length while the natural frequencies for the 00 fiber orientation is more compared to other orientations for out of plane vibrations irrespective of the geometrical dimensions. The natural frequencies for other orientations are more compared to 00 orientation for specific modes due to high stiffness in the torsional direction.

Effect of Control Parameters on Erosion Wear Performance of Glass-Epoxy Composites Filled with Waste Marble Powder

Effect of Control Parameters on Erosion Wear Performance of Glass-Epoxy Composites Filled with Waste Marble Powder

Analysis of Strength Parameters at Tension of Epoxy-Glass Composites with Rubber Recyclate Addition

Abstract The aim of the research was to analyze the strength parameters of epoxy-glass sandwich composites with the addition of rubber recyclate. Material samples were subjected to a static tensile test performed on a universal testing machine in accordance with the current standard for fiber-reinforced composite materials. The test results showed that the addition of rubber recyclate increases the plastic parameters of the composite, which allows considering the use of the tested material for structures loaded with the vibration and noise scale. The use of rubber recyclate to modify the strength parameters of the composite allows to reduce the amount of rubber waste and ensures the durability of the new material.

Finite element analysis of tensile behaviour of glass fibre composites under varying strain rates

Glass-epoxy Composite materials are extensively used in the complex engineering applications due to their better strength to weight ratio, corrosion and fatigue resistant properties. However, to achieve an efficient material for its adequate use, its behaviour at various strain rates is to be well understood, which could be best achieved by carrying out numerical simulations. The present study is made to understand the strain rate sensitivity with various orientations of the fibres in 6 layered, [0]6, [0/90/0] s and [0/30/60] s, laminates. FEM simulations are carried out for a strain rate range of 10−3 to 103 s−1 for tensile loading. L S DYNA software is used to understand the stress–strain behaviour of the composite material for the various strain rates, which have been compared with the experimental results. It is observed that the tensile properties like the Young’s modulus, tensile strength and toughness increase with increase in the strain rates of the glass epoxy composites for different orientations of the plies. The simulation results are in good agreement with the experimental results and in line with the results available in literature.

Parametrically-upscaled continuum damage mechanics (PUCDM) model for multiscale damage evolution in bending experiments of glass-epoxy composites

This paper demonstrates the effectiveness of parametrically-upscaled continuum damage mechanics (PUCDM) models for multiscale damage analysis of S-2 glass fiber/SC-15 epoxy matrix composite beams subjected to single-edge notched bending (SENB) tests. The SENB experiments with [012/9012] double-ply and [08/908/08] triple-ply composite beams use synchrotron X-ray phase-contrast imaging for in-situ damage characterization. PUCDM models represent a class of thermodynamically-consistent multiscale constitutive models that bridge length-scales through explicit incorporation of representative aggregated microstructural parameters (RAMPs) in constitutive coefficients. Functional forms of RAMPs are generated through machine learning tools, operating on a micromechanical analysis database. The efficient PUCDM-based FE simulations reveal multiscale damage phenomena in the SENB experiments.

Effect of Ply Orientation on Residual Stresses and Their Influence on Mode I Fracture Toughness of Glass-Epoxy Composites with 0°//0° Crack Interface

Effect of Ply Orientation on Residual Stresses and Their Influence on Mode I Fracture Toughness of Glass-Epoxy Composites with 0°//0° Crack Interface

Finite element analysis on MWNT reinforced S-glass composite

Fiber reinforced composite is a composite material consisting of a matrix reinforced by a fabric. Shear strength can be defined as the maximum shear stress that a material is capable of sustaining. Shear strength is calculated from the shear fracture load and the shear loaded area. Interlaminar shear stress (ILSS) is the shear stress observed between the laminae of a laminate. The objective of the present work is to perform finite element analysis on neat and CNT reinforced S glass epoxy composite (CRSE) using ANSYS software to estimate the instantaneous shear modulus (ISM) and observe the effect of notch separation on the measured ILSS. In S glass epoxy composite (SGEC), least and peak values of ILSS and ISM are 14.79 MPa, 35.35 MPa and 15.19 MPa, 33.12 MPa respectively when the notch separation is 5 mm and 1 mm.

Effect of Hybrid Fillers on the Bandgap Energy of Glass Epoxy Composites

Polymer composites are used increasingly in industrial applications due to their outstanding electrical, thermal, and mechanical properties. There is a vast literature on the advantages and limitations of nano and micro fillers and the effects of fillers on different properties of the polymers are reasonably understood. However, such information on the effects of a hybrid combination of nano and micron fillers is limited. In this investigation, the effect of hybrid fillers has been investigated in terms of the microstructure, optical absorption and electrical properties namely dielectric constant, AC conductivity and AC breakdown strength. Though different fillers are used, the bandgap energy varies over a narrow range of 2.5–3.2 eV. The hybrid fillers tend to influence the crystallinity and impart divergent optical absorbance spectra. The dielectric properties reveal dependence on the nature of the fillers and there are marked differences between the effects of conductive and insulating fillers, while the same is not observed in the case of the optical absorption spectra.

Mechanical characteristics of glass epoxy composites with Yttrium powder fillers

The addition of fillers will vary the mechanical properties of fibre reinforced polymer composites. Experimental studies are carried out to understand the effect of Yttrium powder as filler material in glass-epoxy composites in the research work. The E-glass/epoxy composite plates filled with changing concentrations of Yttrium powder (0% and 5% by weight of epoxy) were prepared initially. As per ASTM 3039 standard, the samples were tested for tensile test and found that the sample with 5% Yttrium was observed with higher ultimate stress and elongation percentage than the sample without Yttrium. Further, the samples were tested for their hardness as per ASTM E92-17 standard, 22.7 ± 1 Hv was observed for the sample with 5% Yttrium and 2.39 ± 0.5 Hv for the sample made without the addition of Yttrium. The significance of the addition of pure Yttrium powder as filler material is proved, and the results on the effect of addition of Yttrium powder as filler are elaborated in this work.