Fiber Reinforced Polymer Matrix Research Articles

A novel embedded all-solid-state composite structural supercapacitor based on activated carbon fiber electrode and carbon fiber reinforced polymer matrix

Composite structural supercapacitors (CSSs), that provide both mechanical and electrochemical properties, have great potential for applications in electric vehicles, unmanned aerial vehicles and portable electronic devices with reduced overall system weight and volume. In this paper, a novel composite structural supercapacitor device is designed and fabricated, mainly consisting of energy storage units (flexible devices) and a structural unit (carbon fiber reinforced polymer, CFRP). KOH activated carbon cloth (ACC) and PVA-KOH gel electrolyte are selected as the electrode and electrolyte of the energy storage units, respectively. The specific capacitance, energy density and power density of 1:1 ACC-CSS reach 88 mF⋅g−1, 9.9 mWh⋅kg−1 and 445.5 mW⋅kg−1, respectively. Meanwhile, the flexural strength, flexural modulus and shear strength of 1:1 ACC-CSS achieve 230 MPa, 21 GPa and 8.75 MPa, respectively. In addition, the excellent stability of electrochemical performance of 1:1 ACC-CSS under various external loads is verified by electrochemical three-point bending, electrochemical tensile and electrochemical tensile fatigue tests as well. Experimental results show that even after mechanical failure, 1:1 ACC-CSS can still maintain its electrochemical performance. The combination of good electrochemical and mechanical properties of 1:1 ACC-CSS makes it a promising and competitive candidate for the development of composite structural energy storage devices.

Experiment and Simulation Study of the Effect of Fillers on Mechanical Properties of Sustainable Composite

Abstract Natural fiber reinforced polymer matrix composites are gaining increasing attention as engineering materials for advanced applications, including high performance ballistic armor components. This requires superior mechanical properties, such as toughness. Jute fiber reinforced composites are currently being explored as possible advanced engineering materials. Therefore, the objective of this study is to investigate the mechanical characteristics of epoxy composites reinforced with jute fibers and steel fillers. In the present study, three types of the composite of two-way jute carpet and steel fillers were reinforced with epoxy, with different rates of each material.

Effects of contact friction and ply blocking on the crush behaviour of thin-walled composite structures: A numerical study

The present paper presents a three-dimensional composite damage model for predicting the crush response of thin-walled structures, i.e., cylindrical tubes, manufactured employing fibre-reinforced polymer–matrix composites. This computational model is based upon a Continuum Damage Mechanics (CDM) approach and accounts for both the intralaminar and interlaminar damage as well as nonlinear behaviour that occur in the composite materials. Experimental data, obtained from published literature, are employed to validate the proposed composite damage model. A comparison between the experimental and computationally predicted results, including the load response, energy absorption and damage morphology, shows good agreement. Subsequently, the validated computational model is employed to investigate the effects of contact friction and ply blocking on the crush response of thin-walled composite structures. The results reveal that the friction between the tube/platen surfaces has a positive effect on the crushing performance of the composite structures and the ply blocking can somehow inhibit the crushing performance of the investigated composite structures.

Auxetic Composite Laminates with Through-Thickness Negative Poisson's Ratio for Mitigating Low Velocity Impact Damage: A Numerical Study.

Auxetic materials are those that exhibit negative Poisson’s ratios. Such a unique property was shown to improve the indentation and impact resistances. Angle-ply composite laminates can be designed to produce negative Poisson’s ratio at the laminate level due to the large anisotropicity of the individual layer and the strain mismatch between adjacent layers. This paper investigates the effect of through-thickness negative Poisson’s ratio on the low velocity impact behaviors of carbon fiber reinforced polymer matrix composite laminates, including the global impact behaviors, as well as the delamination, and the fiber and matrix damage. Results from numerical investigations show consistently reduced fiber and matrix tensile damage in the auxetic laminate in all plies, in comparison to the non-auxetic counterpart laminates (up to 40% on average). However, the auxetic laminate does not present a clear advantage on mitigating the delamination damage or the matrix compressive damage.

Hygrothermal aging behavior and flexural property of carbon fiber-reinforced polyethylene terephthalate glycol composites

Fiber-reinforced polymer matrix composites during engineering applications can be influenced by critical environmental conditions (e.g., water and temperature), probably causing a negative impact on the mechanical performance. In this work, the hygrothermal aging behavior and flexural property of carbon fiber (CF)-reinforced polyethylene terephthalate glycol (PETG) composites were investigated at different aging temperatures and days. The CF/PETG composites were fabricated using the hot-press molding method. The mathematical fitting model and finite element analysis method were employed to reveal the hygrothermal aging behavior and the moisture absorption evolution. After 90 days of aging, the water uptakes of the specimens at 25°C, 45°C, and 60°C are 0.55%, 0.62%, and 1.67% for PETG and 0.47%, 0.54%, and 1.52% for CF/PETG, respectively. The flexural strengths of the CF/PETG composites at 25°C, 45°C, and 60°C after 90 days of aging decrease by 28.6%, 30.2%, and 32.2% as compared with the non-aging composites, respectively. The water uptakes of the CF/PETG composites tend to increase with the increase in cyclic aging time interval. The flexural strengths of the composites with the cyclic aging intervals of 2, 5, 10, and 15 days first decrease and then increase slightly. The knowledge gained in this study will benefit future design optimization of the CF/PETG composite material and lay the foundation for its engineering application.

Extraction and characterization of natural lignocellulosic fibres from Typha angustata grass

In recent years, efforts have been made to reduce deforestation to conserve the ecosystem. In the current scenario, agro-cultivated products are used instead of wood for engineering applications. Thus, natural lignocellulosic fibres are used as a reinforcing material and have been extremely attractive to industries and the scientific community during the past few decades. This study aimed to examine the use of natural fibres extracted from Typha angustata grass as reinforcement in polymer matrix composites. The density of the fibres was 1.015 g/cc. Chemical analysis confirmed that T. angustata fibres (TAFs) have a cellulose content of 73.54 wt%, a hemicellulose content of 10.11 wt%, a lignin content of 6.23 wt% and a wax content of 0.23 wt%. The crystallinity index (65.16 %) and crystalline size (6.40 nm) were identified by X-ray diffraction (XRD) analysis. The presence of functional groups in the TAFs was examined by employing Fourier-transform infrared spectroscopy (FTIR). The presence of cellulose at peak intensities of C2, C3 and C5 in the TAFs was confirmed using 13C nuclear magnetic resonance (NMR) spectroscopy. The single fibre tensile test revealed that the tensile strength was 665 ± 7 MPa and Young's modulus was 27.45 ± 3.46 GPa. The thermal stability of the TAFs was examined by thermogravimetric analysis (TGA), and the prominent peak was observed at 298.48 °C, with a kinetic activation energy of 67.99 kJ/mol. The surface roughness of the fibres was analysed by atomic force microscopy (AFM) with an accuracy of 1 nm. The above-mentioned outcomes indicated that the TAFs have desirable properties that are comparable to existing natural fibres and suggested to be utilised as the possible reinforcement to fabricate the fibre-reinforced polymer matrix composites.

Effect of Nanofillers on the Mechanical Properties of Vinyl Ester Resin Used as a Carbon Fiber Reinforced Polymer Matrix

Effect of Nanofillers on the Mechanical Properties of Vinyl Ester Resin Used as a Carbon Fiber Reinforced Polymer Matrix

Multi-output optimization and characterization of molybdenum disulfide coated coir fiber using osmosis surface coating technique

ABSTRACT Rise in environmental consciousness has now motivated researchers to produce biodegradable reinforcements to replace non-degradable synthetic fibers. The surface modification increases the adhesive properties and mechanical strength of natural fibers, thus enhancing the properties of the composites. This study uses osmosis surface coating technology to coat molybdenum disulfide (MoS2) on coir fiber. The three parameters used in this method are temperature (℃), time (h), and MoS2 weight percentage while responses include coating concentration and tensile strength. The strength of the modified coir fiber (MCF) increased significantly compared to neat coir fiber (NCF). Taguchi–Grey Relational Analysis (GRA) was used to optimize and study the influence of parameters on responses. Properties of MCF synthesized with optimum parameters were studied and compared to NCF. Field Emission-Scanning Electron Microscope (FE-SEM), Energy Dispersion Spectroscopy (EDS) and X-ray Diffraction (×RD) results confirmed the successful coating of MoS2 over the coir surface. Thermo-gravimetric Analysis (TGA) indicated that the heat-carrying ability of MCF was enhanced compared to NCF. Water absorption studies revealed that surface coating reduced the water intake of NCF by 11% and improved the adhesion property of the fiber’s surface. This technology is appropriate to integrate excellent properties into natural fiber-reinforced polymer matrix composites.

An experimental study on two body abrasive wear behavior of natural fiber reinforced hybrid polymer matrix composites using Taguchi analysis

In earlier days the synthetic fibre composite material was considerably used for the secondary structures of automobile and aircrafts. But by knowing the performance at critical and elevated conditions natural fiber reinforced polymer matrix composites have been receiving considerable attention as the attribute for synthetic fiber reinforced composites for its functional efficiency, tailorable properties and strength to weight ratio. In the present study, abrasive wear behavior of natural fibre reinforced hybrid polymer matrix composite was carried out using pin-on-disc wear testing rig for abaca, basalt and hybrid abaca- basalt fibre reinforced epoxy using L9 orthogonal array. The tests were carried out on silicon carbide paper with a grit size of 320 µm with varying parameters of Load, Speed, and Time. From the obtained results, it is concluded that the optimal parameters for minimum weight loss is observed at load 10 N, speed 200 rpm and time of 10 min for basalt fibre reinforced epoxy composite and the maximum weight loss is observed for abaca fibre reinforced epoxy composite at load 30 N, 300 rpm and time of 20 min. The results also reveal that the material composition is the most influencing factor affecting the weight loss of the specimen followed by load, time and speed for the adopted testing conditions.

A Study on the In-Plane Shear-after-Impact Properties of CFRP Composite Laminates.

Impact loading on carbon fiber reinforced polymer matrix (CFRP) composite laminates can result in a significant reduction in their residual properties, and the (ShAI) properties of the composite material are essential to obtain the material allowable values of the shear dominated composite structures. In order to obtain the ShAI properties of the composite material in pure shear stress at a coupon level, this study presents theoretical, experimental, and numerical methods and analysis work on the in-plane shear and ShAI properties of the composite laminates. Theoretically, a method of sizing the composite specimen loading in shear is developed through comparing the load values due to buckling and the material failure. Following this, both impact tests using the drop-weight method and ShAI tests using the picture frame test method are conducted, and the influences of the impact energies on the impact damage and the residual ShAI values are evaluated. Moreover, a progressive failure finite element model based on the Hashin’s failure criterion and the cohesive zone model is developed, and a two-step dynamic analysis method is performed to simulate the failure process of the composite laminates under impact loading and ShAI loading. It is found that the impact damage with the cut-off energy, 50 J, causes a 26.8% reduction in the residual strength and the residual effective shear failure strain is about 0.0132. The primary reason of the shear failure is the propagation of both the matrix tensile failure and interlaminar delamination. It can be concluded that the proposed theoretical, experimental, and numerical methods are promising factors to study the ShAI properties of the composite materials.

Use of a neural network constitutive model for the size-dependent effects of curing on the deformation response and failure of fiber-reinforced polymer matrix composites

Use of a neural network constitutive model for the size-dependent effects of curing on the deformation response and failure of fiber-reinforced polymer matrix composites

High-content continuous carbon fibers reinforced PEEK matrix composite with ultra-high mechanical and wear performance at elevated temperature

It remains challenging to incorporate high-content fibers in fiber-reinforced polymer matrix composites to significantly enhance their mechanical properties. This work prepared polyether ether ketone (PEEK) matrix composite reinforced with 66 wt% carbon fibers with 0°/90° prepreg layer by compression molding, with aim to further increase the carbon fibers content in PEEK-based composites to improve the mechanical and wear properties at different temperatures, especially high temperature. The composite exhibits tensile and flexural strength of both exceeding 1000 MPa at room temperature, 810 ± 10 MPa and 521 ± 12 MPa at 200 °C and 458 ± 22 MPa and 290 ± 18 MPa at 300 °C, respectively. Especially at 300 °C, the composite demonstrates specific strength of 290 MPa/(g/cm3), which is superior to many magnesium or aluminum alloys (18–86 MPa/(g/cm3)). Further, the composite has a lower wear rate (5.47–12.80 × 10−7 mm3/Nm) at 200 °C by 1–2 orders of magnitude that of some materials with lubricating particles, and the wear surface is dominated by mild adhesive wear instead of abrasive wear at room temperature. The ultra-high mechanical and friction wear properties are attributed to the high content of staggered 90° carbon fibers, great interface bonding between the fibers and PEEK matrix, and self-lubricating effect of fibers and PEEK particles in the composite. This opens up a new performance level and provides a new idea for high-temperature applications of high-strength fiber-reinforced resin matrix composites.

Effect of fiber orientation on the mechanical properties of unidirectional basalt fiber reinforced polymer matrix composites

Polymer matrix composite materials have attracted the researchers over a period due to its superior specific strength, compared to conventional materials. Bio-based fibers have started to emerge rapidly for industrial components, encompassing the technological/scientific aspects and the economic, environmental and social issues. Amongst the variety of bio-based fibers, basalt fiber occupies a prominent position, due to its overall production and unique chemistry-related features. It is chemically inert and non-reactive. In the present investigation, unidirectional basalt fiber of 240GSM at different orientations is added as reinforcement with a fixed weight percentage of 55% to LY556-HY951 epoxy-hardener combination as matrix. Fabrication is carried out by conventional hand lay-up technique. Mechanical characterization such as, tensile, flexural, hardness and inter laminar shear strength tests are conducted for the fabricated material. Morphological studies are conducted using scanning electron microscope (SEM) to visualize the fiber pull out, presence of voids and matrix-fiber adhesion characteristics. From the results obtained, it can be concluded that the highest strengths are obtained for laminates with zero-degree fiber orientation, which makes it suitable to be used for engineering, structural and biomedical applications

Synergetic enhancement of interfacial properties and impact resistant of UHMWPE fiber reinforced composites by oxygen plasma modification

This study reveals the synergetic enhancement of oxygen plasma treatment on the interfacial properties and impact resistant of ultrahigh molecular weight polyethylene (UHMWPE) fiber-reinforced polymer matrix composites (PMCs). The UHMWPE fiber reinforcement was modified by oxygen plasma with different parameters including input power, treatment time and gas flow rate. Then, the surface physicochemical properties of modified fibers were analyzed. Oxygen plasma modified UHMWPE/vinyl ester composites exhibited an enhanced interface shear performance of 90.99%, which would significantly influence the mechanical properties of the composites. The optimal parameters were proved to be an input power range of 150–180 W, a time range of 120–150 s, and a gas flow rate of 8sccm, at which situation the tensile strength had been enhanced 10.67%, the impact-resistant damage projection area and dent depth had been reduced up to 51.93% and 24%, respectively. Simultaneously, the energy dissipation pattern dominated by fiber fracture was gradually formed in the modified composites, which maximize exploitation of the fiber-reinforcing effect and improved the impact resistance.

Oil Palm Empty Fruit Bunch (OPEFB) Fiber-Reinforced Acrylic Thermoplastic Composites: Effect of Salt Fog Aging on Tensile, Spectrophotometric, and Thermogravimetric Properties

The prioritization of agroindustry fiber wastes as raw materials in development of composites has become a challenge to obtain higher value-added products with targeted applications. In this study, natural fiber-reinforced polymer matrix composites were elaborated using two fiber sizes (605 μm and 633 μm) of oil palm empty fruit bunch (OPEFB) and acrylic thermoplastic resin. In doing so, resin and fibers were mixed at room temperature by maintaining filler content of 42 wt. % for all formulations. In addition, thermomechanical compression moulding was used as composite manufacturing process at four processing temperatures (80, 100, 120, and 140°C). All formulations were subsequently exposed to salt fog spray aging for 330 hours. The effects of accelerated aging process on mechanical, spectrophotometric, and thermogravimetric characteristics were studied. On the whole, results have shown feasibility to use a facile method to elaborate composites based on waterborne acrylic matrix and OPEFB fibers. After salt spray testing, it was observed detectable levels of Aspergillus spp. of fungi in all samples, as a result of phylogenetic organization of microbial activity. Tensile behavior of composites was significantly influenced by processing temperature and fiber size. In broad terms, their overall mechanical properties were improved by the increase of temperature. Additionally, infrared spectroscopy results showed important bands mainly associated to biodegradation of cellulose, hemicellulose, and lignin. On the other hand, two degradation stages were mainly identified in thermogravimetric evaluation. Noteworthy, aging had no significant effect on the thermal properties of composites.

Free vibration analysis of fiber-metal laminated composite plates using differential, generalized and harmonic quadrature methods: experimental and numerical studies

PurposeThis study aims to demonstrate the numerical application of differential quadrature (DQ) methods and show the experimental application of free vibration analysis of fiber-metal laminated composite (FML) plates with various boundary conditions.Design/methodology/approachThe FMLs are hybrid structures consisting of fiber-reinforced polymer matrix composites such as carbon, glass, aramid and different metal sheets, and are currently widely used in the automobile, aircraft and aerospace industries. Thus, free vibration analysis of these hybrid materials is necessary for the design process. The governing equations of motion are derived based on the classical plate theory. The DQ, generalized DQ (GDQ) and harmonic DQ (HDQ) differential quadrature methods have been used to solve the governing equations of an FML composite plate numerically. The accuracy and convergence of the numerical model have been verified by comparing the results available in the published literature with the results obtained from these methods. Moreover, an experimental procedure has been performed in order to compare the results against those of the numerical methods.FindingsIt is noteworthy that a high degree of similarity and accuracy was observed between the numerical results obtained by the DQ methods and the experimental results. Thus, the present study validates the applicability of the DQ methods for designing the FML composite plates.Originality/valueIn this study, the advantages of the DQ methods have been demonstrated differently from previous studies on the vibration analysis of the FML plates.

Dynamic fracture of glass fiber-reinforced ductile polymer matrix composites and loading rate effect

The dynamic fracture of S-2 glass fiber-reinforced polymer matrix composites (FRPMCs) was investigated in this study. The matrix ductility was improved by a recently developed network topology modification technique via mixing partially reacted substructures (mPRS). The composite material was manufactured and characterized by micro-CT scanning and scanning electron microscopy (SEM). Dynamic single-edge notched bending (d-SENB) experiments were performed on the composites by using a modified split-Hopkinson pressure bar. Each specimen's fracture process was visualized by ultrafast X-ray imaging. Such in-situ radiography enabled identifying the damage initiation below 50-μm scale and inspecting its propagation through the internal structures of opaque composites, thereby accurately quantifying the composites' mechanical properties. Furthermore, the identical d-SENB experiments were designed and the digital image correlation (DIC) was employed to monitor the stress wave propagation on the composite specimens . The force and deflection measurements were modified and correlated to the physical damage processes. Besides, quasi-static SENB experiments were conducted to identify the loading rate effects on the composites' fracture behaviors . The force and deflection history, bending stiffness , energy dissipation , and fracture toughness at different loading rates were quantified and compared. Finally, post-fracture analysis by micro-CT scanning and SEM provided physical observations on the variation of the fracture morphology at different loading rates.

Stochastic aspects of crack deflection and crack path prediction in short fiber reinforced polymer matrix composites

Owing to the production process, short fiber reinforced composites exhibit a pronounced anisotropy of both elastic properties and crack growth resistance. In particular the latter issue has a major impact on crack deflection and inevitably has to be taken into account for the sake of an accurate prediction of crack paths. The perpendicular axes of transverse isotropy are associated with the fiber orientations, whereupon a crack in transverse direction encounters the largest fracture toughness. While the local mean fiber orientations in polymer matrix composites are determined by the injection molding process, their statistical fluctuations can approximately be described in terms of Gaussian random field models. Furthermore, statistical variations of the volume fraction of fibers and the fiber–matrix adhesion give rise to stochasticity of the local ratio of fracture toughness anisotropy. Influencing factors of prediction regions of crack paths obtained from finite element simulations with an adapted J-integral deflection criterion are investigated, just as stochastic aspects of bifurcation phenomena of crack deflection observed under mode-I loading.

Development of Sustainable Jute/Epoxy Composite and Assessing the Effect of Rubber Crumb on Low Velocity Impact Response

ABSTRACT In the current study, the experimental assessment of influence of rubber crumb on the low velocity impact (LVI) behavior of jute epoxy composites are carried out using two types of impactors namely hemispherical and conical. Hand layup technique is used to fabricate the proposed composites. The rubber crumb is incorporated in the epoxy resin with 1.5 wt%, 3 wt%, and 5 wt%. Results revealed that incorporation of 3 wt% of rubber crumb resulted in better LVI response compared to its counterparts. Fractography studies revealed that inclusion of rubber crumb particles enhances the adhesion between resin and fiber, thereby increasing the energy absorption. In addition, they aid in reducing damage area and increasing penetration threshold of proposed composites. The current study’s systematic technique serves as a model for the efficient use and conversion of waste rubber crumb into usable natural fiber reinforced polymer matrix composites for LVI applications.

Sustainable Manufacture of Natural Fibre Reinforced Epoxy Resin Composites with Coupling Agent in the Hardener

Lignocellulosic natural fibres are hydrophilic, while many matrix systems for composites are hydrophobic. The achievement of good mechanical properties for natural fibre-reinforced polymer (NFRP) matrix composites relies on good fibre-to-matrix bonding at the interface. The reinforcement is normally coated with an amphiphilic coupling agent to promote a strong interface. A novel alternative approach is to dissolve the coupling agent in the hardener for the resin before creating the stoichiometric mix with the base epoxy resin. During composite manufacture, the hydrophilic (polar) end of the coupling agent migrates to surfaces (internal interfaces) and bonds to the fibres. The hydrophobic (non-polar) end of the coupling agent remains embedded in the mixed resin. Mechanical testing of composite samples showed that silane added directly to the matrix produced a NFRP composite with enhanced longitudinal properties. As pre-process fibre coating is no longer required, there are economic (shorter process times), environmental (elimination of contaminated solvents) and social (reduced worker exposure to chemical vapours) benefits arising from the new technique.