Showing papers in "Journal of Composite Materials in 2016"
TL;DR: In this paper, composites of polyvinyl alcohol and bio-carbon (i.e., biochar) were prepared by a solution casting method to investigate their electrical conductivity and mechanical and thermal properties.
Abstract: The composites of polyvinyl alcohol and bio-carbon (i.e. biochar) were prepared by a solution casting method to investigate their electrical conductivity and mechanical and thermal properties. The ...
95 citations
TL;DR: In this article, a decision-making model is introduced to evaluate and select the most appropriate nonwoven natural reinforcement fiber/polypropylene-based composites for interior parts in the automotive industry considering various evaluation criteria simultaneously.
Abstract: Recent emphasis on the proper utilization of the available natural resources as well as the compatibility between industrial sustainability and the environment have recognized the natural fiber reinforced polymer composites as a valuable type of materials. The final features of natural fiber reinforced polymer composites are strongly influenced by the characteristics of their constituents. Several factors affect implementing natural fiber reinforced polymer composites in automotive applications, which make it a matter of multi-criteria decision making problem. In this work, a decision-making model is introduced to evaluate and select the most appropriate non-woven natural reinforcement fiber/polypropylene-based composites for interior parts in the automotive industry considering various evaluation criteria simultaneously. The analytical hierarchy process was utilized to assess 15 potential alternatives of different natural fiber/polypropylene composites. The evaluation process considered simultaneous six evaluation criteria, namely tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength and the maximum water absorption of the composites. Such approach is implemented here for the first time to enhance the selection process of natural fiber reinforced polymer composites for automotive application and to expand the future sustainable design possibilities in this sector. Both impact and flexural strengths were found to have the major priority in the evaluation process. The treated flax/polypropylene composite with 30 wt% fiber loading alternative was found to be the best with regard to the overall evaluation criteria. Date palm fiber/polypropylene composites were found to be potential considering the whole desired evaluation criteria.
92 citations
TL;DR: In this paper, the authors investigated the properties of randomly oriented strand composites and quantified the effect of strand size on their properties, including tensile, compressive, shear and fatigue.
Abstract: There is an emerging interest in the aerospace industry to manufacture components with intricate geometries using discontinuous fibre carbon/polyether–ether–ketone moulding systems (obtained by cutting unidirectional tape into strands). This type of material system is termed randomly oriented strand composites and is appealing for structural applications as it bridges the gap between the lack of formability of continuous fibre composites and the lack of performance of short fibre composites. The objective of this study was to investigate mechanical properties (tensile, compressive, shear and fatigue) of randomly oriented strand composites and to quantify the effect of strand size on their properties. Overall, properties were found to be highly variable and dependent on the strand length. Interestingly, tensile, compressive and shear strength had similar magnitudes and exhibited the same failure mechanisms (strand fracture and debonding). This experimental work expands the knowledge base for randomly orien...
80 citations
TL;DR: In this paper, the influence of filler shape and filler content on the physical and mechanical properties of silicon carbide/epoxy nanocomposites was investigated using silicone carbide nanoparticles and nanowhiskers.
Abstract: In this study, the influence of filler shape and filler content on the physical and mechanical properties of silicon carbide/epoxy nanocomposites was investigated using silicon carbide nanoparticles and nanowhiskers. Samples containing 0.5, 1, 2 and 4 wt% of β-silicon carbide nanowhiskers and nanoparticles in epoxy resin were prepared using a high-intensity ultrasonic liquid processor and casting technique. Mechanical and physical tests such as tensile, flexural, hardness, and wear along with a morphological investigation by FT-IR, scanning electron microscopy and transition electron microscopy were performed. Results of mechanical tests indicating about 20% and 40% improvement were achieved in nanoparticle (1 wt%) and nanowhisker (2 wt%) reinforced samples, respectively. Also mechanical experiment results have been evaluated with theoretical models. Tribological results show that wear and frictional properties improved about 50% and 30%, respectively, by adding silicon carbide nanoparticles (4 wt%) and n...
69 citations
TL;DR: In this paper, Cement mortars with different contents of nano silica (NS) were fabricated and tested and their compressive and flexural strengths showed significant increases in strength.
Abstract: Cement mortars with different contents of nano silica (NS) were fabricated and tested. Their compressive and flexural strengths showed significant increases. Theoretical calculation and thermogravi...
67 citations
TL;DR: In this paper, the effects of porosity on the matrix-dominated mechanical properties of unidirectional carbon fiber-reinforced plastic composites were evaluated using X-ray computed tomography and mechanical test.
Abstract: The effects of porosity on the matrix-dominated mechanical properties of unidirectional carbon fiber-reinforced plastic composites were evaluated using X-ray computed tomography and mechanical test...
66 citations
TL;DR: In this article, unsupervised cluster analysis is performed on the acoustic emission signals of textile composites to understand the failure mechanisms in textile composite composites based on acoustic emission signal.
Abstract: Understanding the failure mechanisms in textile composites based on acoustic emission signals is a challenging task. In the present work, unsupervised cluster analysis is performed on the acoustic ...
62 citations
TL;DR: In this paper, the effect of fiber surface modification on the mechanical properties such as tensile strength, flexural strength, ILSS, and impact strength of the composites were investigated.
Abstract: The aim of the present work was to study the effect of fiber surface treatment on the structural, thermal and mechanical properties of luffa fiber and its composites. Fibers were treated with alkali (5% conc.), benzoyl chloride, and potassium permanganate (KMnO4) (0.05%) at room temperature. The untreated and treated fibers were characterized and morphologically analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The effect of fiber surface modification on the mechanical properties such as tensile strength, flexural strength, ILSS, and impact strength of the composites were investigated. It is observed that chemically treated Luffa cylindrica-reinforced epoxy composites significantly improved the mechanical properties of the composite. The maximum strength properties were found with benzoyl chloride-treated fiber-reinforced composite.
56 citations
TL;DR: An effective parametric analysis on the mechanical properties (tensile and flexural strength) of bagasse fiber-reinforced vinyl ester (BFRVE) composites were conducted, and then the fabrication process parameters were optimized by using Taguchi and analysis of variance techniques.
Abstract: In the present communication an effective parametric analysis on the mechanical properties (tensile and flexural strength) of bagasse fiber-reinforced vinyl ester (BFRVE) composites were conducted, and then the fabrication process parameters were optimized by using Taguchi and analysis of variance techniques. Composites plates were fabricated by Taguchi’s L18 experimental design as the function of process parameters such as fiber length, fiber content, fiber diameter, sodium hydroxide concentration and sodium hydroxide treatment duration. The optimum process parameters to obtain the maximum strength values were identified using signal-to-noise ratio calculations. Then, the results were analyzed to know the percentage contribution of each fabrication process parameter on the tensile and the flexural strength using analysis of variance. A multivariable non-linear regression model was developed to predict the strength values and compared with experimental strength values. The developed models were validated ...
55 citations
TL;DR: In this paper, the cutting temperature, cutting forces, and composite surface roughness were measured under different cutting conditions for the end milling of unidirectional carbon fiber reinforced plastics.
Abstract: The surface machining of carbon fiber reinforced plastics materials is a challenging process, given the heterogeneity and anisotropic nature of composites, which, combined with the abrasiveness of the fibers, can produce some surface damage and extensive tool wear. The cutting temperature is one of the most important factors associated with the tool wear rate and machinability of these materials, which are also affected by the mechanical and thermal properties of the workpiece material and the cutting conditions. In this work, the cutting temperature, cutting forces, and composite surface roughness were measured under different cutting conditions for the end milling of unidirectional carbon fiber reinforced plastics. Cutting speeds ranging from 200 to 350 m/min; a feed rate of 0.063 mm/rev; fiber orientations of 0, 45, 90, and 135°; and a 0.5 mm depth of cut were considered. The results show that the cutting speed and fiber orientation have a significant influence on the cutting temperature and cutting fo...
54 citations
TL;DR: In this paper, a modified Fourier-Ritz approach has been adopted to analyze the free vibration of axially loaded laminated composite beams with arbitrary layup and general boundary conditions, which include classical boundaries, elastic boundaries, and their combination.
Abstract: In this paper, a modified Fourier–Ritz approach has been adopted to analyze the free vibration of axially loaded laminated composite beams with arbitrary layup and general boundary conditions, which include classical boundaries, elastic boundaries, and their combination. The influences of Poisson effect, axial deformation, couplings among extensional, bending and torsional deformations, shear deformation, and rotary inertia are incorporated in the formulation. In this present method, regardless of boundary conditions, the displacements and rotation components of the beam are invariantly expressed as a standard Fourier cosine series and several auxiliary closed-form functions. These auxiliary functions are introduced to eliminate any potential discontinuities of the original displacement function and its derivatives, throughout the whole beam including its ends, and to effectively enhance the convergence of the results. Since the displacement field is constructed to be adequately smooth in the whole soluti...
TL;DR: In this paper, the influence of the carbon nanotubes (CNTs) content on the fiber/matrix interfacial shear strength (IFSS) in glass/fiber epoxy composites was measured by means of push-in and push-out tests.
Abstract: The influence of the carbon nanotubes (CNTs) content on the fiber/matrix interfacial shear strength (IFSS) in glass/fiber epoxy composites was measured by means of push-in and push-out tests. Both ...
TL;DR: In this paper, the mechanical properties and dynamic response of hybrid filler-modified epoxy/carbon fiber multiscale composites were investigated and the hybrid fillers composed of multi-walled carb...
Abstract: In this article, the mechanical properties and dynamic response of hybrid filler-modified epoxy/carbon fiber multiscale composites were investigated. The hybrid fillers composed of multiwalled carb...
TL;DR: In this paper, surface hybrid composite was fabricated on Al6061 base sheets using friction stir processing (FSP) and samples were subjected to various numbers of FSP passes from one to four with Al2O3/TiB2 powder.
Abstract: In this study, surface hybrid composite was fabricated on Al6061 base sheets using friction stir processing (FSP). Samples were subjected to various numbers of FSP passes from one to four with Al2O3/TiB2 powder. Influence of number of FSP passes was studied on distribution of Al2O3/TiB2 particles in aluminium matrix, microstructure, hardness, and wear properties of specimens. The results showed that increase in the number of passes causes a more uniform dispersion of composite particles and thus, decreases particles clustering. In addition, an increase in the number of FSP passes was found to decrease the matrix grain size of the surface hybrid composite. It was observed that the hardness increased as the number of passes increased due to presence and pinning effect of hard Al2O3/TiB2 particles. Also, at higher number of passes, the surface hybrid composite wear resistance was increased.
TL;DR: In this article, the thermal bifurcation behavior of cross-ply laminated composite cylindrical shells embedded with shape memory alloy fibers is investigated and properties of the constituents are assumed to be temperatur...
Abstract: Thermal bifurcation behavior of cross-ply laminated composite cylindrical shells embedded with shape memory alloy fibers is investigated. Properties of the constituents are assumed to be temperatur...
TL;DR: In this article, various amounts of carbon nanotubes (CNTs), nanosilver (AgNPs), and polyaniline (PANI) were incorporated at the same pot into the structure of composite polyacrylonitrile (PAN) nanof...
Abstract: In this study, various amounts of carbon nanotubes (CNTs), nanosilver (AgNPs), and polyaniline (PANI) were incorporated at the same pot into the structure of composite polyacrylonitrile (PAN) nanof...
TL;DR: In this paper, the authors present a critical review of papers dealing with solid particle erosion characteristics of polymer matrix composites, metal matrix composite, and ceramic matrix composite composites.
Abstract: This article presents a critical review of papers dealing with solid particle erosion characteristics of polymer matrix composites, metal matrix composites, and ceramic matrix composites. In addition, the solid particle erosion characteristics of coatings for composite materials are also reviewed. Attention was paid to type of a reinforcement material (fiber/filler), amount of fiber/filler, fiber orientation, and interfacial strength between fiber/filler and matrix, which affect the solid particle erosion in addition to the variables affecting the solid particle erosion of monolithic materials, that is, impact angle, particle velocity, temperature, particle flux, and erodent properties such as shape, size, hardness, and so on. General characteristics of solid particle erosion for composites are extracted from the review of the papers.
TL;DR: In this article, the vibro-acoustic modulation method was employed to detect delamination and kissing bond in composites, where both a large-amplitude and low-frequency pumping wave and a probing wave were used to vibrate the structure and a sideband ratio was used to estimate the extent of nonlinear interactions between the two input waves in the structure.
Abstract: In this paper we employ a nonlinear acoustic method, namely, the vibro-acoustic modulation method, for the detection of delamination and kissing bond in composites. Both a (large-amplitude and low-frequency) pumping wave and a (low-amplitude ultrasound) probing wave are used to vibrate the structure. Permanently bonded piezoceramic transducers are used for both excitation and measurement. A side-band ratio is used to estimate the extent of nonlinear interactions between the two input waves in the structure. Current results show that the proposed method successfully differentiates the intact specimens from both the delamination and the kissing bond specimens used in this study.
TL;DR: In this paper, structural supercapacitors that can carry mechanical loads as well as can store electrochemical energy simultaneously were developed by impregnating capacitors with polysilicon.
Abstract: We have developed structural supercapacitors that can carry mechanical loads as well as can store electrochemical energy simultaneously Structural supercapacitors are fabricated by impregnating ca
TL;DR: In this article, the authors synthesized cellulose/gypsum composites in the presence and absence of sodium alginate and investigated the interaction between the composite components as well as the mechanical properties of t...
Abstract: We synthesized cellulose/gypsum composites in the presence and absence of sodium alginate and investigated the interaction between the composite components as well as the mechanical properties of t...
TL;DR: In this paper, the effects of equi-biaxially fabric prestressing on flexural properties of plain-weave woven fabric-reinforced composites have been investigated.
Abstract: The flexural properties of plain-weave woven fabric-reinforced composites have been investigated to clarify the effects of equi-biaxially fabric prestressing on flexural characteristics. The prestressed composite samples were manufactured by applying the symmetrical tension load to both warp and weft yarns prior to matrix curing. The fabricated samples were tested under different fabric orientation angles, i.e. from warp to bias direction. The decline in the flexural properties of the prestressed composite due to matrix creep was checked. From three-point bending tests, the prestressed samples exhibited a maximum increase in the flexural performance, such as the strength and modulus, of ∼16% at a prestressing level of 50 MPa when compared with unprestressed counterparts. The level of improvement in the flexural properties reduced with increasing fabric orientation angle. The creep was induced in the prestressed matrix and subsequent decline in the improved flexural properties was indicated in the prestressed samples. The decline in flexural properties occurred mostly during the short-term creep.
TL;DR: In this paper, the orthogonal microplane triad is formed by adding two microplanes parallel to the yarn, one of which is normal to the plane of the laminate.
Abstract: An accurate prediction of the orthotropic elastic constants of woven composites from the constituent properties can be achieved if the representative unit cell is subdivided into a large number of finite elements. But this would be prohibitive for microplane analysis of structures consisting of many representative unit cells when material damage alters the elastic constants in each time step in every element. This study shows that predictions almost as accurate and sufficient for practical purposes can be achieved in a much simpler and more efficient manner by adapting to woven composites the well-established microplane model, in a partly similar way as recently shown for braided composites. The undulating fill and warp yarns are subdivided into segments of different inclinations and, in the center of each segment, one microplane is placed normal to the yarn. As a new idea, a microplane triad is formed by adding two orthogonal microplanes parallel to the yarn, one of which is normal to the plane of the laminate. The benefit of the microplane approach is that it is easily extendable to damage and fracture. The model is shown to give realistic predictions of the full range of the orthotropic elastic constants for plain, twill, and satin weaves and is extendable to hybrid weaves and braids.
TL;DR: Enhanced tribological and location-specific properties achieved in functionally graded metallic composites make them potential materials for futuristic engineering components as mentioned in this paper, and they can be used for future engineering components.
Abstract: Enhanced tribological and location-specific properties achieved in functionally graded metallic composites make them potential materials for futuristic engineering components The present investiga
TL;DR: In this article, the effect of different polymeric interlayers on ballistic performance of multi-layered ceramic armors against AP projectile is investigated, and the finite element results obtained from various armor layups show the potentiality of multilayer ceramic armor in extending conoid fracture through the ceramic layers, thus leading to the increase in the armor performance.
Abstract: In this study, ballistic behavior of multi-layered ceramic armors under high velocity impact is studied numerically. The model consists of 2D-axisymmetric Lagrangian approach with Johnson–Holmquist constitutive model for alumina ceramic tiles, Mie–Gruneisen equation of state for polymeric interlayers, and Johnson–Cook constitutive relation for Armor Piercing (AP) projectile. The finite element results obtained from various armor layups show the potentiality of multi-layered ceramic armor in extending conoid fracture through the ceramic layers, thus leading to the increase in the armor performance. It is illustrated that besides ceramic armor layup, interlayers of ceramic tiles have a significant role in increasing the armor performance. Finally, the effect of different polymeric interlayers on ballistic performance of multi-layered ceramic armors against AP projectile is investigated. In order to measure the ballistic performance of the armors, various criteria are introduced. Depth of penetration of the ...
TL;DR: In this paper, the microstructure of short-fiber reinforced composites is analyzed and shown to be mainly governed by the manufacturing process like injection injection, and the micro-structure itself is influenced by their manufacturing process.
Abstract: Mechanical properties of short-fiber reinforced composites are crucially influenced by their microstructure. The microstructure itself is mainly governed by the manufacturing process like injection...
TL;DR: In this article, the thermal and mechanical properties of graphene/epoxy nanocomposites were investigated, and Pristine graphene and functionalized graphene were used as nano-reinforcement.
Abstract: The research investigated the thermal and mechanical properties of graphene/epoxy nanocomposites. Pristine graphene and functionalized graphene were used as nano-reinforcement in the nanocomposites...
TL;DR: In this article, a three-dimensional finite element model of the induction welding of carbon fiber/polyphenylene sulfide thermoplastic composites is developed, which takes into account a stainless steel mesh heating element located at the interface of the two composite adherends to be welded.
Abstract: A three-dimensional finite element model of the induction welding of carbon fiber/polyphenylene sulfide thermoplastic composites is developed. The model takes into account a stainless steel mesh heating element located at the interface of the two composite adherends to be welded. This heating element serves to localize the heating where it is needed most, i.e. at the weld interface. The magnetic, electrical, and thermal properties of the carbon fiber/polyphenylene sulfide composite and other materials are identified experimentally or estimated and implemented in the model. The model predicts the temperature–time curves during the heating of the composite and is used to define processing parameters leading to high-quality welded joints. The effect of the heating element size and input current on the thermal behavior is investigated, both experimentally and using the developed model. The welds quality is assessed through microscopic observations of the weld interfaces, mechanical testing, and observations of the fracture surfaces. A comparison with two other welding processes, namely resistance welding and ultrasonic welding is finally conducted.
TL;DR: In this article, the effects of improvement methods on the mechanical and thermal properties of textile fiber reinforced (T-FRP) composites were investigated and five different chemical methods namely,...
Abstract: In this study, the effects of improvement methods on the mechanical and thermal properties of textile fiber reinforced (T-FRP) composites were investigated. Five different chemical methods namely, ...
TL;DR: In this article, a solution utilizing metallic inserts in the hole is proposed to tackle the problems of bolt detachability and hole clearances, which are needed to facilitate on-site assembly, reduce the stiffness and joint efficiency.
Abstract: As the use of fibre reinforced polymer materials in bridge construction is becoming more popular, appropriate joining techniques, particularly for field joints, are necessary. Bolted joints are a common method for joining fibre reinforced polymer structures. The main advantage of bolted joints is their detachability, but they have a number of shortcomings. On the one hand, hole clearances, which are needed to facilitate on-site assembly, reduce the stiffness and joint efficiency. On the other hand, it is not possible to rely on the beneficial effects of bolt pre-defined tension loads, i.e. load transfer in friction, due to the considerable losses of bolt tension caused by the creep deformation in the composite material. To tackle these problems, a solution utilising metallic inserts in the hole is proposed in this paper. A series of experimental tests have been conducted to investigate the effect of inserts on the bolt-tension relaxation, the stiffness and the load-bearing behaviour of joints. Finite element analyses were also employed. The study demonstrates several benefits of the inserts: the bolt tension relaxation is minimised, the load transfer by friction may be feasible to be utilised in the bridge service state and the joint efficiency is increased in terms of stiffness and strength.
TL;DR: In this article, the hybridization effect of polypropylene (PP) with polyvinyl alcohol (PVA) fibers in engineered cementitious composites (ECCs) was investigated.
Abstract: In the present study, the hybridization effect of polypropylene (PP) with polyvinyl alcohol (PVA) fibers in engineered cementitious composites (ECCs) was investigated. For this purpose, PVA reinforcing fiber was partially replaced by PP fibers with different circular, triangular, and trilobal cross-sectional shapes. The flexural behaviors of the ECCs containing hybrid fibers including first-crack strength, post-crack strength, and toughness were studied under three-point bending test. It was found that hybridization with nonround cross-sectional shape PP fibers had positive effect on the ductility but decreased the flexural strength of resultant ECCs. The greater reduction in toughness and post-peak strength was observed for composite containing circular PP fibers. The results indicated that partially replacement of PVA fibers with nonround cross-sectional shape PP fibers can be considered to be promising method to reduce the costs of ECC production along with attaining improved deformability.