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In this study, two types of composites, polybutylene terephthalate (PBT) and epoxy resin (ER), reinforced with 20% of glass fiber (GF) are used as the comparative research objects. Their mechanical properties after thermal aging at 85~145 °C are evaluated by tensile strength and fracture morphology analysis. The results show that the composites have similar aging laws. The tensile strength of GF/PBT and GF/ER decrease gradually with the increase of aging temperature, while their elastic moduli are independent of the thermal treatment temperature. Scanning electron microscopy study of the fracture surface shows that separation of glass fiber from PBT and ER matrix becomes more obvious at higher aging temperature. The fibers on the matrix surface appear clear and smooth, and the whole pulled out GFs can be observed. As a main mechanical strength degradation mechanism, the deterioration of interface adhesion between the matrix and GF is discussed. A large difference in coefficients of thermal expansion of the matrix and GF is a main factor of the mechanical degradation. [ABSTRACT FROM AUTHOR]

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

Fiber-reinforced polymer composites are manufactured using various methods, with vacuum-assisted resin transfer molding (VARTM or VARIM). This study's primary focus lies in assessing how the orientation of sampling impacts the mechanical properties of glass fiber-reinforced pure and nanocomposites. 2 wt.% nano Al2O3- doped and non-doped composites were produced using the VARTM process. Tensile, flexural, and density test specimens were extracted from three distinct zones and two distinc direction those aligned horizontally to the resin flow (HRF) and those oriented vertically to the resin flow (VRF). Remarkably, results showed up to a 3.91% increase in values from samples in the third zone, particularly on the vacuum outlet side. To facilitate precise stress value comparisons across plates, uniform sample orientation and consistent zone selection are essential. [ABSTRACT FROM AUTHOR]

In the present work, the mechanical and morphological characterization of bamboo-glass fiber-nanoclay epoxy hybrid composites is carried out. Materials are prepared using a hand lay-up process with different wt.% of bamboo fiber, glass fiber, nanoclay, and epoxy. As per ASTM standards, fabricated composite laminates are cut and tested for tensile and flexural properties. The bamboo fiber epoxy composites (BFEC) display the tensile and flexural strength of 137 and 170 MPa, respectively. Hybrid composites, viz. bamboo-glass fibers epoxy composites (BGFEC), display improved tensile (180–240 MPa) and flexural (225 to 320 MPa) strengths compared to BFECs. Glass fiber epoxy composites (GFEC) display maximum tensile (265 MPa) and flexural (360 MPa) strengths among all the composites. Furthermore, the addition of nanoclay improves the tensile (by 6 to 8%) and flexural (by 8 to 10%) strengths of epoxy, BFEC, BGFEC, and GFECs. SEM analysis is conducted for fractured tensile specimens to understand the reasons for specimen failure. [ABSTRACT FROM AUTHOR]

Glass fiber (GF) was modified by KH-550 to improve the compatibility between GF and epoxy resin (EP) matrix, and glass fiber reinforced epoxy resin composites (EP/GF) were prepared. The effects of GF content on the insulation and mechanical properties of EP/GF composites were studied. The results show that GF can be uniformly dispersed in EP when the content of GF does not exceed 30%. When the content of GF reaches 40%, GF agglomerates, and the EP matrix produces defects such as pores. When the content of GF is 30%, the insulation performance and comprehensive mechanical properties of EP/GF composites were the best. Compared with pure EP, the volume resistivity of the composites is increased by 36.9%, the relative dielectric constant ( εr) and dielectric loss factor (tan δ) are decreased by 11.4% and 8.9%, respectively. The short-term AC breakdown voltage value is increased by 27.8%, the bending strength is increased by 38.2%, the impact strength is increased by 40.0%, the tensile strength is increased by 40.4%, the elongation at break is decreased by 11.1%, and the hardness is increased by 5.9%. [ABSTRACT FROM AUTHOR]

Glass fiber reinforced composites have attracted great, widely used specific industrial areas such as defense, aerospace, etc. However, composite plates are defenseless to damage accumulation such as matrix cracks, fiber delamination, and delamination, which limits the application of glass composites in specific industrial areas at limited strength levels. Therefore, analysis of the behavior of composites under the outof- plane loads is essential to optimize such material. This study examines the out-of-plane loading performance of multi-scale glass/epoxy composite laminate. To improve the load-carrying performance in the direction of out-of-plane, the halloysite nanotube (HNT) particle reinforcement was introduced to the epoxy matrix. The three-point bending tests were conducted to attain the out-of-plane load-carrying performance. The findings show that the flexural strength increases by almost 20% for the HNT-modified glass/epoxy composite compared to the unmodified counterpart; meanwhile, the toughness is effectively improved with the HNT addition. Moreover, the damage process of specimens in three-point bending tests was detected by microscopic examination. [ABSTRACT FROM AUTHOR]

In the current study, the nano-composites of unidirectional carbon and glass fiber reinforcedepoxy resin with multi-walled carbon nanotubes (MWCNTs) were separately prepared by hand lay-up and hot pressing of fiber epoxy prepregs. Three types of MWCNT derivatives (parentCNT, low carboxylated CNT (LCCNT) and higher carboxylated CNT (HCCNT)) were dispersed into the epoxy resin/fiber composites. The improved mechanical properties observed in the three component composites could be attributed to the uniform dispersion of CNTs in epoxy/ fiber matrices, nanosize of the additives and the improved interfacial interactions between the composite components. The COOH functional groups could also be effective in the increase of mechanical traits because they induce the amphiphilic nature into CNTs for better dispersion and to generate the better glass fiber/epoxy (E/G) and carbon fiber/epoxy (E/C) interactions. HCCNT led to the best mechanical properties among all the samples due to its higher carboxyl content. HCCNT also changed the curing peak of epoxy in DSC and improved its thermal stability. For instance, the final residual mass for E/HCCNT was 15.4% at 600 °C compared to 13.92% for the pure epoxy while the values of 17.55 and 16.48% were observed at 500 °C for E/HCCNT and epoxy, respectively. The observed effect of COOH functionality on the void formation within the composite and on the better CNT dispersion in the matrix can be considered as an important observation for investigating the E/C/CNTs nanocomposites. [ABSTRACT FROM AUTHOR]

To improve the thermal and mechanical properties of epoxy resins, epoxy-functionalized POSS (E-POSS) and glass fiber (GF) were used to reinforce epoxy resin (E51) composites. The tensile, thermo-mechanical, fractured, and thermal tests were carried out to characterize these hybrid materials. The results show that E-POSS and GF could significantly improve the mechanical and thermal properties of epoxy resins due to high crosslink density of resin matrix and synergistic interaction between the epoxy resin, E-POSS, and GF. Compared with the pure E51 resin, the tensile strength of the E51 + E-POSS (10%) + GF (16%) sample increased by 257.6%, and the thermal decomposition temperature (Td5%) of the E51 + E-POSS (10%) + GF (16%) sample increased by 32 °C to 378 °C. [ABSTRACT FROM AUTHOR]

Glass fiber/polymer composites find extensive application in marine industry; however, the durability of theses marine structures has always been a matter of concern owing to their continuous exposure to harsh marine environment. The objective of this study is to consolidate and analyze the work that has been carried out so far, primarily focusing on the influence of the marine‐environment characteristics on water absorption and its subsequent impact on the mechanical properties of glass fiber reinforced composites. It is found that immersion time and operational temperature are the two prominent factors that influence the durability of these polymer composites. Moisture causes reversible changes such as plasticization and irreversible changes such as hydrolysis, cracking, and crazing which subsequently exerts a detrimental effect on the physical, chemical, and mechanical properties of epoxy resins. During the initial stage of water absorption, the moisture content increased rapidly with the immersion time, and then it increased slowly as the immersion time stretched until the moisture content in the specimen reached a saturation level. Prolong exposure in water not only led to a substantial deterioration in static mechanical properties; it also altered the mode of failure from a brittle matrix‐ductile fiber to ductile matrix‐brittle fiber. [ABSTRACT FROM AUTHOR]

To further improve the preparation efficiency and properties of bamboo fiber reinforced polymer composites (BFRPs) fabricated by the vacuum-assisted resin transfer molding (VARTM) process. Here, the bamboo fiber/glass fiber mesh reinforced polymer hybrid composites (BGRPs) were fabricated by VARTM to determine the effects of three fiber stacking sequences (namely, GBBGBBG, BGBGBGB, and BBGGGBB; B: bamboo fiber, G: glass fiber mesh) on the physical and mechanical properties, as well as void characteristics of BGRPs (i.e. BGRP-1, BGRP-2, and BGRP-3). The results showed that the incorporation of glass fiber meshes could shorten the injection time of epoxy resin and improve the mechanical properties of BFRPs. BGRP-1 exhibited the lowest water absorption (1.31%) and the highest shear strength (15.55 MPa). Glass fiber meshes on the surface and bottom of BGRP-1, respectively, served as buffer layers to retard mechanical damage, so that BGRP-1 had the best drop hammer impact properties. BGRP-2 represented the highest flexural strength and flexural modulus of 92.22 MPa and 6.69 GPa, respectively. The mechanical properties of BGRP-3 were inferior to those of BGRP-1 and BGRP- 2, and more voids were observed in the middle of BGRP-3 in micro-CT slices induced by inadequate epoxy resin impregnation on bamboo fibers. [ABSTRACT FROM AUTHOR]

The current study focuses on the investigation of the synergetic effect of graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) on the flexural properties, hardness and water absorption characteristics of glass fiber reinforced polymer (GFRP) laminated composite materials. The laminated composite materials were fabricated with various configuration of filler reinforcements using vacuum assisted hand lay-up technique. Further, micromechanical analysis was performed using Halpin-Tsai model to investigate the synergistic effect of CNT/GNP hybrid glass fiber reinforced epoxy nanocomposites. It was observed that the CNT and GNP reinforced hybrid composite exhibited highest value of flexural strength and hardness; the respective values being 38% and 29% higher in comparison to the neat epoxy composite. Furthermore, among GNP and CNT, the composite containing former reinforcement exhibited better mechanical properties. The composites containing nanoparticles also exhibited better water uptake characteristic, where the weight gain for hybrid composite was 1.004%, whereas, for neat epoxy composite, the weight gain was 1.210%. This was attributed to the ability of nanofillers to restrict the intermolecular movement of the surrounding GFRP composites, which delays the relaxation of polymer chains, thereby reducing the diffusion of tiny molecules through the composites. It was also observed that the addition of GNPs has a strong effect on the elastic properties of the hybrid glass fiber reinforced epoxy nanocomposite than the addition of CNTs. [ABSTRACT FROM AUTHOR]

This study investigates the influence of reduced graphene oxide (rGO) coated glass fabrics on the strain sensing and the mechanical characteristics of fiber‐reinforced composites. Graphene oxide was applied in two thicknesses (threefold and fivefold coatings) onto a fabric using a padder mangle machine followed by thermal reduction and infused with an epoxy to manufacture rGO‐enhanced composite. The tensile modulus and flexural strength of the rGO‐enhanced composites with threefold coating were improved by 27% and 6.2%, respectively, compared with the equivalent composite manufactured without rGO. The normalized resistance (ΔR/R0) of composites increased by 0.89% and 3.48% under a cyclic tensile force of 1000 and 4000 N. The magnitude of ΔR/R0 was stable within 30 cycles suggesting a consistent strain sensing performance with a gauge factor of 15.55. The electrical response of the rGO‐enhanced composite was evaluated using a new industrial standard for sensors, by assessing calibration curves. The composite showed low hysteresis and low electrical viscosity which make these materials suitable for industrial piezoresistive strain sensors. [ABSTRACT FROM AUTHOR]

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Fiber reinforced polymer (FRP) composites possess excellent specific strength, specific stiffness and controlled anisotropy for which these are extensively used in various engineering applications, like automobile industries, aerospace industries, marine industries, space industries, electronics industries and many more. Glass fibers (GF), carbon fibers (CF) and aramid fibers (AF) are common reinforcements for polymer matrix composites (PMCs). High mechanical properties and wear resistance behaviour of glass fiber reinforced composites are the premises for the current experimental research on the effect of fiber orientation on the tensile strength of the polymeric composite materials. The glass fiber reinforced epoxy resin composite was prepared by wet lay-up method, followed by thermal treatment. [ABSTRACT FROM AUTHOR]

Nanodiamonds (NDs) are the potential fillers to provide excellent mechanical and multi-functional capabilities. The growing interest in using NDs in a variety of fields has prompted researchers to use NDs to prepare various structural composites. Proper dispersion and interfacial adhesion between the NDs and the polymer matrix are required to use NDs as effective reinforcement in polymer nanocomposites. In this study, the mechanical properties of the epoxy-based glass fiber (GF)- and carbon fiber (CF)-reinforced laminated composites with the incorporation of annealed nanodiamonds (NDs) in the epoxy matrix was analyzed. The epoxy resin was modified through the step-wise addition of annealed NDs from 0.1 to 0.5 wt.%. The surface-modified NDs were characterized by SEM, XRD, FTIR, and TEM. The test results predict that the tensile strength was increased by 25, 23%, and tensile modulus increases by 33, 135% for GF- and CF-reinforced hybrid composites corresponding to the addition of 0.3 wt.% NDs into the epoxy matrix. Also, the flexural strength increased by 36, 37%, and flexural modulus increased by 71, 37% for the GF- and the CF-reinforced hybrid composites corresponding to the addition of 0.3 wt.% NDs into the epoxy matrix. These improved properties of hybrid composites are mainly due to the enhanced mechanical interlocking and weak Van der Waals force between the NDs particles that caused the efficient dispersion of NDs in the epoxy matrix and it has been reported in this study. [ABSTRACT FROM AUTHOR]

Recently, the utilization of hybrid basalt/glass fiber reinforced polymer (HBGFRP) nanocomposites has increased significantly in structural applications due to their light weight nature, superior strength-to-weight ratio, and excellent mechanical, chemical, and thermal properties. This study aims to investigate the effects of various drilling parameters and filler weight content on delamination and surface roughness on HBGFRP nanocomposites filled with combination of multi-walled carbon nanotubes (MWCNTs) and nano-silica particles (SiO2) in equal weight proportions of 0%, 1%, and 2%. These nanocomposite laminates were fabricated using the manual lay-up method followed by compression molding with a novel stacking order of fibers 01B/02G/02B/02G/02B/02G/01B consisting of 12 layers.. In this work, the Box-Benkhen Design of Response Surface Methodology (RSM) was employed to optimize the drilling parameters, including spindle speed, feed rate, drill diameter, and weight content of MWCNTs + SiO2. The nanocomposites containing 1.0wt. % MWCNTs + SiO2 demonstrated the most significant reduction in the delamination factor, achieving a 24% reduction. The lowest delamination factor recorded was 1.29, obtained with a spindle speed of 1350 rpm, a feed rate of 0.1 mm/rev, a drill diameter of 6 mm, and the addition of 1.0wt. % MWCNTs + SiO2. Increasing the spindle speed resulted in a further reduction in the delamination factor. The surface roughness measured was 1.213 µm, indicating a relatively smooth surface. It was evident that increase in feed rate and drill diameter corresponded to increase in both delamination factor and surface roughness. [ABSTRACT FROM AUTHOR]

Effect of hybridization on dynamic mechanical properties of calotropis procera/glass fiber reinforced epoxy hybrid composites was investigated. The hand layup method was used to fabricate composites by varying fiber reinforcement of calotropis procera and glass fiber composition at 5, 10, 15, and 20 wt%. Dynamic mechanical analysis of composites was carried out in the temperature range of 25°C–180°C at the frequency of 1 Hz. Study revealed a marginal shift in glass transition temperature for fiber reinforced composites compared to neat epoxy which indicates the higher temperature resistance of the fiber reinforced composites. The higher interfacial bonding was revealed by the damping ratio analysis with the increase in glass fiber reinforcement in the hybrid composites. The hybrid composites exhibited increase in storage and loss modulus with increase in glass fiber content. Scanning electron microscopy was carried out to study the fracture surface morphology of the composite specimens. [ABSTRACT FROM AUTHOR]