Glass Fiber-reinforced Composites Research Articles

Mechanical, Flame-Retardant and Dielectric Properties of Intumescent Flame Retardant/Glass Fiber-Reinforced Polypropylene through a Novel Dispersed Distribution Mode.

The application of continuous glass fiber-reinforced polypropylene thermoplastic composites (GF/PP) is limited due to the inadequate flame retardancy of the polypropylene (PP) matrix. Apart from altering the composition of the flame retardants, the distribution modes of flame retardants also impact material performance. In this study, an alternative approach involving non-uniform distribution is proposed, namely, dispersed distribution, in which non-flame-retardant-content layers (NFRLs) and/or low-flame-retardant-content layers (LFRLs) are dispersed among high-flame-retardant-content layers (HFRLs). The mechanical, flame retardant and dielectric properties of GF/PP with intumescent flame retardant (IFR/GF/PP) are investigated comparatively under uniform, gradient, and dispersed distributions of the flame retardants. The results demonstrate that non-uniform distribution exhibits superior flame retardant performance compared to uniform distribution. Dispersed distribution enables IFR/GF/PP to attain enhanced mechanical properties and reduced dielectric constants while maintaining excellent flame-retardant properties.

Effect of temperature on the mechanical behavior of glass fiber reinforced with hollow glass particle-filled epoxy composites

The design of marine ships and aircraft components with hollow glass particle-filled fiber-reinforced composites demands an understanding of their performance under outdoor conditions. The continuous glass fiber-reinforced epoxy matrix filled with hollow glass particles in the range of 0–0.3 vol fraction was prepared by the compression molding machine. The influence of temperature exposure on the mechanical behavior of glass fiber-reinforced hollow glass particle composites was studied by conducting tensile and flexural tests. The temperature exposure varying from room temperature up to 60 °C was used to investigate the effect of service temperature on the hollow glass particle-filled fiber composite specimens. Differential scanning calorimetry (DSC) analysis was conducted to study the glass transition behavior of the composites. The incorporation of microspheres in the glass fiber composites gradually reduced the tensile and flexural strength, while their specific values increased as increasing the microspheres. The hollow glass particle-filled fiber composites tested at 60 °C exhibited a decrease in tensile and flexural strength compared with room temperature. As the température of the test spécimens was nearer to the glass transition value, the polymer chain was softened, leading to a reduction in strength. In contrast, the modulus values remain unaffected by increasing the temperature to 60 °C.

Experimental study of the mechanical and optical properties of glass-polyester fiber composite based on response surface methodology

Due to the intricate amalgamation of various components, composite materials boast mechanical properties that surpass those of their constituents. Among these composite materials, glass fiber-reinforced polyester composites emerge as prominent contenders, finding extensive utility, especially in agricultural greenhouse construction. These structures garner significant acclaim for their exceptional ability to withstand adverse weather conditions, ensure prolonged durability, and transmit light efficiently, thus creating optimal growing conditions. Consequently, they have become the favored choice among farmers seeking dependable and sustainable environments for cultivation. Within the scope of this study, we employ Response Surface Methodology (RSM) as a comprehensive tool to delve deeply into the mechanical and optical characteristics inherent in such composite materials. Our investigation is meticulously tailored to unravel the intricate interplay among crucial factors such as fiber content, length, and plate thickness, elucidating their direct impacts on mechanical properties like stress and elasticity modulus. Our rigorous examination reveals that the pinnacle of mechanical performance is attained within a specific range: fiber content ranging from 20% to 40%, fiber lengths spanning 35 to 45 mm, and plate thicknesses measuring between 0.6 to 3 mm. Furthermore, our meticulous analysis of transmittance measurements uncovers an intriguing correlation: thinner thicknesses and lower fiber content correspond with heightened light transmission across the visible spectrum. Conversely, elevating the fiber content or thickness enhances mechanical robustness but concurrently diminishes light transmittance. Thus, achieving a harmonious equilibrium among these attributes becomes imperative for the pragmatic construction of agricultural greenhouses. Additionally, we venture into incorporating ultraviolet (UV) plastic films to augment the optical prowess of these composites, further elevating their efficacy in greenhouse applications. By embarking on this comprehensive investigation, our overarching objective is to propel sustainable farming practices forward by furnishing a nuanced understanding of the multifaceted factors that shape the performance of glass fiber-polyester composites in agricultural greenhouse applications.

Shock Absorption Capacity of High-Performance Polymers for Dental Implant-Supported Restorations: In Vitro Study.

Restorative materials might significantly affect load transmission in peri-implant bone. The aim of the present study is to evaluate the shock absorption capacity of two different polymeric materials to be used for implant-supported prostheses. A masticatory robot was used to compare the shock absorption capacity of veneered and non-veneered polyetherketoneketone (PEKK), Pekkton®ivory (Cendres+Mètaux), and the glass fiber-reinforced composite (GFRC), TRINIATM (Bicon). Five identical sample crowns for each of the three groups were tested. Forces transmitted at the simulated peri-implant bone were recorded and statistically analyzed. The statistical analysis of forces transmitted at the simulated dental implant revealed significant differences between the materials tested and between these materials and zirconia, glass ceramic, composite resin, and acrylic resin. Only differences between PEKK and veneered PEKK and between PEKK and one of the previously tested composite resins were not statistically significant. PEKK samples demonstrated significantly greater shock absorption capacity compared to GFRC. PEKK revealed optimal shock absorption capacity. Further studies are needed to evaluate its efficacy in the case of long-span prostheses with reduced prosthetic volume.

Assessment of the effectiveness of selected coatings for protection against UV radiation in glass fiber reinforced composites (GFRP)

Assessment of the effectiveness of selected coatings for protection against UV radiation in glass fiber reinforced composites (GFRP)

Performance analysis of fiber-reinforced polypropylene composite laminates under quasi-static and super-sonic shock loading conditions for impact application

In the present research, glass and basalt fiber-reinforced polypropylene composites’ behaviour in quasi-static and dynamic conditions is studied. Composites were fabricated by vacuum assisted Compression molding method. Composites failure under quasi-static tension and compressive conditions was studied along with its failure behaviour under low-velocity impact and super-sonic shock loading under dynamic conditions. The study results showed that basalt fiber-reinforced polypropylene (Basalt/PP) composite’s tensile and compressive strength is higher than glass fiber-reinforced polypropylene (Glass/PP). The Basalt/PP showed no penetration against low velocity impact (LVI) with negligible deformations till 50 J. However, the Glass/PP perforated at 50 J with various failure patterns occurring at back side. The fiber-matrix interface adhesion plays an important role in super-sonic shock loading by absorbing shock wave energy due to ductile nature of polypropylene and the two composites absorbed energy via matrix and fibers failure, no brittle failure of laminates occurred under shock loading.

Mechanical properties of continuous glass fibre-reinforced composites made by material extrusion

AbstractThis paper presents an experimental and numerical study on the mechanical properties of continuous glass fibre-reinforced composites fabricated using the material extrusion technique. Specimens with varying numbers of reinforcement layers are 3D printed using a MarkForged Mark Two printer. Both flexural and tensile tests are conducted to evaluate the performance of these specimens. In addition, a numerical modelling approach based on finite-element analysis (FEA) is developed to simulate the flexural and tensile properties of the composites. A comparison between the model predictions and experimental results reveals a reasonable agreement. The findings of this research provide valuable insights into the emerging field of continuous fibre-reinforced 3D printing technology, enabling users to design and fabricate parts that meet the specific requirements of their applications with a high level of confidence.

Determination of progressive damage modelling parameters and calibration studies of 8-harness satin weave S-2 glass fibre reinforced composites

The aim of this article is to present a progressive damage modelling study of 8-harness satin weave S-2 glass fibre-reinforced SC15 epoxy matrix composites. Extensive mechanical properties of the composite were investigated throughout the study. The material was subjected to low-velocity impact (LVI) loading for investigating progressive damage. MAT162 material model in Ls-Dyna commercial finite element software was chosen for modelling damage that occurred in composite structure at the end of LVI test. MAT162 needs different material properties including elastic and strength properties with additional damage parameters. Different standard and non-standard tests were conducted to obtain these properties. Additionally, numerical simulation studies were run to calibrate these material properties. Finally, a set of calibrated material properties of 8HS-S2G/SC15 composite were obtained.

Detection and characterisation of defects in composite materials using microwave non-destructive testing methods

This paper proposes a technique for detecting impact-induced surface and subsurface fractures in Glass Fibre Reinforced Composites (GFRPs) and hybrid composite materials. Various categories of composite samples, namely Unidirectional GFRP, Bidirectional GFRP, Woven mat GFRP and Carbon-flax hybrid composites are fabricated by the hand-layup process, and cracks are induced in the samples by three-point flexural bending test using a Universal Testing Machine. Near-field microwave Non-Destructive Testing (NDT) is employed in detecting the above cracks by recording the S11 parameter from the microwave transceiver probe throughout the sample. For image rendering the resulting outputs are passed as a 2-dimensional array to the image-rendering algorithms, namely Iterative Curve-Based Interpolation (ICBI), Improved New Edge-Directed Interpolation (INEDI) and the Lanczos algorithm. The most suitable algorithm to identify the clear picture and size of crack is identified, and the effectiveness of Microwave NDT for these composites is analysed.

Numerical prediction of thermal conductivity and thermal expansion coefficient of glass fiber-reinforced polymer hybrid composites filled with hollow spheres

The optimal performance of composites enriched with hollow spheres has been reported in contemporary literature, whereas their thermal properties have received less attention. In this regard, a finite element method (FEM)-based micromechanical model has been developed systematically to investigate the role of intra-matrix embedding of hollow spheres on the thermal conductivity and coefficient of thermal expansion (CTE) of unidirectional fiber-reinforced hybrid composites. In so doing, the concept of representative volume element (RVE) considers microstructures comprising an epoxy matrix, E-glass fiber, and E-glass hollow spheres, assuming perfect bonding (ideal interface) between the components and modified approximate periodic boundary conditions. By computing the longitudinal and transverse temperature gradients generated due to the application of uniform heat flux as well as the geometrical variation in RVE owing to temperature enhancement, thermal conductivity and CTE have been respectively determined. Comprehensive evaluations have been conducted to examine the effects of microstructural-level features, including fiber volume content and orientation, plus volume content and thickness of hollow spheres, on the effective thermal conductivity and CTE of pseudo-porous ternary E-glass/epoxy composites.

Effect fiber length on mechanical and thermal properties of glass fiber reinforced polyphenylene sulfide composite

Polyphenylene sulfide (PPS) finds extensive applications in the automotive industry, aerospace electrical, and electronic components, as well as mechanical applications. In order to enhance the toughness and strength of PPS, this study employed long glass fibers as reinforcement material and prepared glass fiber-reinforced polyphenylene sulfide composites (PPS/GF) using melt blending method. Based on fiber length distribution (FLD), this study comparatively analyzed the mechanical and thermal properties of short-cut glass fiber (PPS/SGF3mm) and continuous glass fiber (PPS/LGF) composites. Experimental results demonstrated that with a 5.45% increase in critical fiber length fraction, the tensile strength of PPS/LGF composites exhibited a significant improvement of 11.25%–13.6% compared to PPS/SGF3mm composites. Furthermore, FLD had minimal influence on the thermal stability of the composites, but exerted a significant impact on the crystallization behavior, whereby LGF led to a significant reduction in the crystallinity of PPS composites. These findings suggest that the utilization of continuous glass fibers enables the development of cost-effective and robust PPS composites, meeting the requirements of high strength and high temperature resistance in engineering applications. This study provides valuable insights for material selection and design.

Laser-texturing and traditional surface modification to improve the adhesion of glass fiber-reinforced composite posts to resin cements

ObjectivesThe aim of this study was to perform an experimental evaluation of the synergistic effects of laser-texturing and different traditional surface modification approaches to improve the adhesion of glass fiber-reinforced composite (GFRC) posts to resin-matrix cements used in endodontically treated teeth rehabilitation. MethodsOne hundred and ten freshly extracted mandibular single-rooted premolars were endodontically treated and groups of specimens were divided according to the GFRC cementation after different surface treatment, as follow (n = 10): silane-based conditioning (SIL); 9.7 % HF acid-etching (HF); 35 % H2O2 etching (H2O2); grit-blasting (GB); HF plus H2O2 etching (HFH2O2); 6 W Nd:YAG laser-texturing (L6W); 4.5 W Nd:YAG laser-texturing (L4.5W); 3 W Nd:YAG laser-texturing (L3W); 3 W Nd:YAG plus 35 % H2O2 (L3WH2O2); 3 W Nd:YAG plus SIL (L3WSIL); and untreated (C). GFRC posts were cemented into the tooth root canals using a dual-cured resin cement. Then, specimens were cross-sectioned and mechanically assessed by push-out bond strength tests. Specimens were inspected by optical microscopy and scanning electron microscopy (SEM) at magnification from × 30 up to × 2000. The failure mode was recorded by microscopic analyses after the bond strenght tests. ResultsSurface analyses of the GFRC posts showed a rough and retentive morphological aspect with a removal of the outer epoxy matrix layer and exposure of glass fibers after laser-texturing, grit-blasting, or etching under 35 % H2O2. The highest bond strength values at 21.8 MPa was recorded for GFRC posts after laser-texturing on 3W plus silane-based conditioning followed by the group etched with 35 % H2O2 (20.5 MPa). The failure mode was microscopically characterized as cohesive and mixed pathways. The lowest bond strength values around 5 and 9 MPa and adhesive failure were recorded for the untreated GFRC group or specimens etched with HF. ConclusionsThe combination of acidic etching and silane conditioning with laser-texturing at moderate intensity promoted an adequate surface modification of GFRC posts and increased adhesion to a resin-matrix cement. Such combination of physicochemical approaches can enhance the long-term mechanical behavior of the restorative interface at endodontically treated teeth. Clinical relevanceCombining traditional and novel physicochemical approaches can provide promising adhesion pathways for glass fiber-reinforced composite posts to resin-matrix cements. A high mechanical interlocking of the resin-matrix cements and the stable retention of the teeth root intracanal posts can decrease the risks of clinical failures by fracture and detachment of the intraradicular interface.

Full-scale evaluation of creep coefficients and viscoelastic moduli in honeycomb sandwich pultruded GFRP composite cross-arms: Experimental and numerical study

The utilization of pultruded glass fibre-reinforced polymer composites (PGFRPC) to replace traditional wooden cross-arms in high transmission towers is a relatively recent development. While there have been numerous investigations into enhancing cross-arm structures, there remains a notable absence of research focused on the elastic characteristics of a full-scale PGFRPC cross-arm, particularly one enhanced with a honeycomb sandwich structure. To full-fill the gap, this paper presents an experimental and numerical study through cantilever beam flexural tests on assembled cross-arm condition to examine deflection behavior and the flexural creep response. For deflection behavior, the load was applied up to actual working load. For creep behavior, the hanging load was applied for 1000 h in open area condition followed ASTM D2990 standards. By using Findley's power law, confirming the ability of this empirical approach to simulate the viscoelastic response of the cross-arm. The results obtained prove that the addition of a honeycomb sandwich structure reduced deflection and improved resilience against bending forces, enhancing specific points' elastic modulus slightly. Long-term creep tests revealed Point Y3 had the highest strain, but the enhanced cross-arm displayed superior resistance and a shorter viscoelastic transition period, indicating increased stability. Besides that, the Findley's Power Law Model effectively represented creep behavior for both cross-arm types, with low errors. Over 50 years, both versions showed a significant reduction in average elastic modulus, with the enhanced variant 20 % stronger due to the honeycomb structure. In conclusion, this study validates the superior creep properties of the enhanced PGFRPC cross-arm and demonstrates the honeycomb sandwich structure's substantial role in increasing strength and extending the cross-arm's lifespan, making it a valuable enhancement for such applications.

Mechanical upcycling of single-use face mask waste into high-performance composites: An ecofriendly approach with cost-benefit analysis

The COVID-19 pandemic created an unprecedented demand for PPE, with single-use face masks emerging as a critical tool in containing virus transmission. However, the extensive use and improper disposal of these single-use face masks, predominantly composed of non-biodegradable plastics, has exacerbated environmental challenges. This research presents an innovative method for mechanically upcycling PPEs used in medical sectors i.e. single use face masks. The study investigates a facile approach for reclamation of infection-free and pure polypropylene (PP) plastic from discarded single use face masks (W-PP) and blends it with various vegetable oil percentages (5, 10 and 20 %), resulting in a versatile material suitable for various applications. Melt flow index, rheological behaviour, DSC and FTIR were employed to investigate the effect of vegetable oil/radical initiator through chemical grafting on W-PP properties. The results demonstrate significant enhancements in the tensile strength and modulus of W-PP when blended with vegetable oil and a radical initiator. There was a marked increase in tensile strength (33 %) and strain (55 %) compared to untreated W-PP, rendering W-PP both robust and flexible. Furthermore, we employed this upcycled W-PP in the fabrication of glass fibre-reinforced composites, resulting in notable enhancements in both tensile strength and impact resistance. The upcycled W-PP demonstrates excellent potential for various applications, such as sheet forming and 3D printing, where the non-brittleness of plastics plays a pivotal role in manufacturing high-quality products. The cost-benefit analysis of this approach underscores the potential of upcycling PPE waste as a sustainable solution to mitigate plastic pollution and conserve valuable resources. The applications of this upcycled material span a wide range of industries, including automotive composites, packaging, and 3D printing.

Effect of nanoclay on the mechanical and thermal properties of glass fiber-reinforced epoxy composites

The effects of nanoclay (NC) addition on the thermal and mechanical properties of glass fiber-reinforced epoxy composites were investigated experimentally in this study. Nanocomposite plates were produced for this purpose using three different NC ratios (0.5%, 1%, and 1.5% by weight). Thermal characteristics of nanocomposites were investigated using dynamic mechanical analysis, differential scanning calorimetry, and thermogravimetric analysis. The mechanical and thermal results obtained from composites with three different NC ratios were compared with the results obtained from pure composites. The structures of nanocomposites were investigated with the help of SEM–EDS analyses. Furthermore, the effect of nanoclay on the failure behavior of composites was also investigated. In this study, the highest values in all mechanical properties were obtained from samples with a 1% NC-added. Obtained from 1% NC-added samples: tensile, compressive, shear strengths, elasticity modulus, shear modulus, and Poisson's ratio values were 31.06%, 4.25%, 14.30%, 7.35%, 11.94%, and 12.5% higher, respectively, than the values obtained from pure samples. Maximum loss modulus and maximum storage modulus were obtained from samples with 1.5% and 0.5% NC-added, respectively. In samples with 1.5% NC-added, the highest Tan δ value was obtained. Glass transition temperatures increased with the added NC. It was observed that the fiber–matrix interfaces were more clearly separated in the samples with 1.5% NC-added.Graphical abstract

Comparative study of the mechanical properties of glass and Kevlar fiber-reinforced honeycomb composite

Honeycomb sandwich structures have wide range of applications in the aircraft, automobile, and satellite sectors due to their superior properties such as high specific strength, stiffness, energy absorption, and high impact strength. In this study, mechanical characteristics such as compression, three-point bending, and in-plane impact properties of 3D woven honeycomb composites produced from Kevlar and glass fiber were investigated. The focus of this research is to compare the mechanical performance of woven honeycomb composites developed from these two fibers with similar cell structures. The results revealed that Kevlar fiber honeycomb composite shows higher peak load and energy absorption for flatwise and edgewise compression while in three-point bending and in-plane impact, glass fiber honeycomb composite shows higher peak load, and impact energy absorption. The deformations shown in all the mechanical properties give the ductile behavior for Kevlar fiber and brittle behavior for glass fiber composite. The findings of the study suggest that the failure modes are mostly determined by the nature of the material itself.

Thermal and Morphological Assessment of the Penta-Layered, Hybrid U-Polyester Composite Reinforced with Glass Fibers and Polypropylene

The interaction between the fibers and matrix in a fiber-reinforced polymer composite material is important in figuring out its properties. The incorporation of fibers with polymers can result in composites with enhanced strength and stiffness. This study aims to investigate the thermal and morphological characteristics of hybrid u-polyester composites reinforced with glass fibers and polypropylene. The fabrication of composite specimens was conducted through a straightforward cold press method. The compositions of the composites were held constant, except for the orientation of the glass fibers and polypropylene. In this study, the TG/DTG technique was used to analyze the thermal characteristics of the composites. In addition, transverse thermal conductivity was measured using the ASTM E1530 method. The test results showed that the composite reinforced with glass fibers exhibited the lowest weight loss and minimal thermal conductivity among all the samples, followed by the hybrid composite. Based on the TGA curves of the samples, the matrix experienced a weight loss of 9.7% at a temperature of 300°C, which reduced to 2.6% and 2.1% for hybrid composites and glass fiber-reinforced composites, respectively. DTG curves for composites demonstrate that the hybrid and fiber-reinforced composites degraded at rates of 0.64 mg/min and 0.36 mg/min, respectively, at 392.3°C and 395.7°C. Moreover, transverse thermal conductivity of the composite which consists of five-glass-fibered layers shows a minimal thermal conductivity of 0.05 W/m·K. The morphological properties were also investigated using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The findings from SEM and FTIR showed that a higher proportion of glass fibers led to a more oriented composite structure, demonstrating enhanced crosslinking between fibers and polyester. Therefore, the insights of this study can be used to improve the performance of glass fibers and polypropylene hybrid-laminated composites intended for high-temperature applications.

Flexural creep response of honeycomb sandwich pultruded GFRP composite cross-arm: Obtaining full-scale viscoelastic moduli and creep coefficients

The application of pultruded glass fibre-reinforced polymer composites (PGFRPC) as a replacement material for conventional wooden cross-arm in high transmission towers is relatively new. Although there are several studies on enhancement of the cross-arm structure, there is still a lack of study on the elastic properties of a full-scale PGFRPC cross-arm enhanced with honeycomb sandwich structure. To full-fill the gap, this paper describes an experimental methodology used to obtain the elastic properties of the cross-arm using a three-point bending (3-PB) flexural test by following ASTM D790 standard for deflection behaviour and flexural creep response. The investigation involved several cross-arm members subjected to loading across different span lengths by propose two methods in order to measure the effective cross-arm member section flexural modulus (Ec) and shear modulus (Gc). The creep behaviour of the panels was successfully modeled using Findley's power law, confirming the ability of this empirical approach to simulate the viscoelastic response of the cross-arm. Next predictions were made for up to 50 years of service and the results shows the elastic modulus reduction for the enhanced cross-arm with the honeycomb sandwich structure was approximately reduce to 70 % compare with existing cross-arm which reduce almost 75 % at 50 years of application. The enhanced cross-arm exhibited lower deflection and better creep resistance and increased the bending strength of the cross-arm as well as extended its potential lifespan. Predictions indicated that the enhanced cross-arm maintained better mechanical properties over time compared to the existing one.

Glass Fibre-Reinforced Extrusion 3D-Printed Composites: Experimental and Numerical Study of Mechanical Properties.

The properties of 3D-printed bodies are an essential part of both the industrial and research sectors, as the manufacturers try to improve them in order to make this now additive manufacturing method more appealing compared to conventional manufacturing methods, like injection moulding. Great achievements were accomplished in both 3D printing materials and machines that made 3D printing a viable way to produce parts in recent years. However, in terms of printing parameters, there is still much room for advancements. This paper discusses four of the 3D printing parameters that affect the properties of the final products made by chopped glass fibre-filled nylon filaments; these parameters are the printing temperature, nozzle diameter, layer height, and infill orientation. Furthermore, a polynomial function was fitted to the measured data points, which made it possible to calculate the tensile strength, flexural strength, and Young's modulus of the 3D-printed samples based on their printing parameters. A Pearson correlation analysis was also carried out to determine the impact of each parameter on all three mechanical properties studied. Both the infill orientation and printing temperature had a significant effect on both strengths and Young's modulus, while the effect of nozzle diameters and layer heights were dependent on the infill orientation used. Also, a model with excellent performance was established to predict the three mechanical properties of the samples based on the four major parameters used. As expected from a fibre-reinforced material, the infill orientation had the most significant effect on the tensile strength, flexural strength, and Young's modulus. The temperature was also quite significant, while the nozzle diameters and layer height effect were situational. The highest values for the tensile strength, flexural strength, and Young's modulus were 72 MPa, 78.63 MPa, and 4243 MPa, respectively, which are around the same values the manufacturer states.

An algae-derived partially renewable epoxy resin formulation for glass fibre-reinforced sustainable polymer composites

A brown algae-based renewable epoxy monomer can outperform bisphenol-A based epoxy resin and composite systems by means of thermomechanical properties.