Showing papers in "Journal of Reinforced Plastics and Composites in 2011"
TL;DR: In this article, a novel mechanical extraction process was developed to obtain long bamboo fibers to be used as reinforcement in structural composites, and a single-fiber tensile test at four different span lengths for four span lengths was performed.
Abstract: A novel mechanical extraction process was developed to obtain long bamboo fibers to be used as reinforcement in structural composites. A single-fiber tensile test at four different span lengths for...
207 citations
TL;DR: A review of the modeling of void formation and unsaturated flow in liquid composite molding processes is presented in this paper, where the authors examine modeling efforts considering all the mechanisms involved such as void formation, bubble compression, and gas dissolution.
Abstract: In this study, we present a review of the modeling of void formation and unsaturated flow in liquid composite molding processes. We examine modeling efforts considering all the mechanisms involved such as void formation and transport, bubble compression, and gas dissolution. In particular, the capillary number is identified as a key parameter for void formation and transport. Numerical simulation studies are reviewed, and a state-of-the-art is presented. The influence of microvoids on the global resin flow is also investigated. To model the unsaturated flow more accurately, we suggest considering the surface tension or capillary pressure, variation in permeability in terms of saturation and fiber displacement, as well as tow saturation. From this investigation, the apparent permeability and pressure profile in saturated and unsaturated flows are compared.
144 citations
TL;DR: In this paper, chemical surface modification of woven bamboo mat with maleic anhydride, permanganate, benzoyl chloride, benzyl chloride, and pre-impregnation were carried out.
Abstract: Chemical surface modification of woven bamboo mat with maleic anhydride, permanganate, benzoyl chloride, benzyl chloride, and pre-impregnation were carried out. These modified fibers were used as reinforcements in epoxy and polyester matrices. The effects of fiber modification on the tensile, flexural, impact, and water absorption properties of the composites were investigated. Flexural properties of maleic anhydride treated bamboo polyester composites improved by nearly 50%. The tensile strength and modulus of permanganate-treated bamboo polyester composite increased by 58% and 118%. The tensile strength and modulus of benzoylated bamboo fiber polyester composite improved by 71% and 118%, respectively. After benzoylation of the bamboo fiber, the water absorption is 16% for the bamboo-epoxy composite compared to 41% by untreated bamboo-epoxy composite. The water absorption by benzylated bamboo reinforced polyester composite was 16.8% compared to 51% by untreated bamboo-polyester composite. Pre-impregnatio...
116 citations
TL;DR: The effect of hybridization of hemp fibers with glass fibers on the impact and fatigue properties of the hybrid biocomposites made from them has been studied in this paper, where the laminates were made by hand layup.
Abstract: The effect of hybridization of hemp fibers with glass fibers on the impact and fatigue properties of the hybrid biocomposites made from them has been studied. The laminates were made by hand layup ...
94 citations
TL;DR: In this paper, maleic anhydride grafted polypropylene and hemp fiber composites were prepared by melt compounding, followed by injection molding, and then they were used to construct composite materials.
Abstract: Polypropylene and hemp fiber composites were prepared by melt compounding, followed by injection molding. Maleic anhydride grafted polypropylene (PP—MAH), maleic anhydride grafted styrene—(ethylene...
89 citations
TL;DR: In this article, the main factors that influence the properties of composite are fiber length and content, and the prediction of optimum fiber lengths and content becomes important, so that composite can be prepared.
Abstract: The main factors that influence the properties of composite are fiber length and content. Hence the prediction of optimum fiber length and content becomes important, so that composite can be prepar...
84 citations
TL;DR: In this paper, the effects of ply thickness on the impact damage mechanism in CFRP laminates are discussed based on the experimental observations, and the experimental results show that ply thickness is positively associated with impact damage.
Abstract: In this article, the effects of ply thickness on the impact damage mechanisms in CFRP laminates are discussed based on the experimental observations. Quasi-isotropic CFRP laminates were manufacture...
82 citations
TL;DR: In this paper, the effect of elevated temperatures on tensile strength of CFRP sheets was evaluated between 20°C and 120°C, and the storage moduli of two types of epoxy resins, with glass transition temperatures (T g) of 42 and 45°C respectively, were tested by DMA.
Abstract: To predict temperature-dependent tensile strength of unidirectional CFRP composites, numerical analysis and model simulation were conducted in terms of experimental results. The effect of elevated temperatures on tensile strength of CFRP sheets was evaluated between 20°C and 120°C, and the storage moduli of two types of epoxy resins, with glass transition temperatures (T g) of 42°C and 45°C, were tested by DMA. The tensile experiments of CFRP sheets show that the tensile strength exhibits stable behavior at the low-temperature range (below glass transition temperature), but drops rapidly during the glass transition region, and then reaches a plateau. Analysis results indicate that the degradation of tensile strength is mainly due to matrix softening and loss of fiber—matrix adhesion, based on which a semi-empirical model is proposed to precisely describe tensile strength reduction as the temperature increases. The parameters of the model consist of the glass transition temperature of polymer matrix, the p...
74 citations
TL;DR: In this article, the tensile, flexural, and impact properties of hybridized kenaf/PALF-reinforced HDPE composite were studied, and a notched Izoid impact test was conducted using a 1-J universal pendulum according to ASTM D256.
Abstract: Hybridization, especially where only variant natural lignocelluloses are combined, is fast receiving encouraging attention because it offers a range of properties that may be difficult to obtain with a single kind of reinforcement. In this study, tensile, flexural, and impact properties of hybridized kenaf/PALF-reinforced HDPE composite were studied. Sheets from which tensile, flexural, and impact specimens were cut out were produced from the compression molding of composite pellets and subsequently conditioned in an oven for 21 h at 103°C. The tensile and flexural specimens were tested according to ASTM D638 and ASTM D790 using a 5-kN INSTRON bluehill universal testing machine accordingly. While a notched Izoid impact test was conducted using a 1-J universal pendulum according to ASTM D256. All specimens were prepared at a fiber ratio of 1:1 kenaf:PALF and fiber lengths of 0.25, 0.5, 0.75, and 2 mm; fiber loadings of between 10% and 70% were utilized for the study. About 0.25 mm fiber showed the best ten...
72 citations
TL;DR: A study on the properties of denture base materials made from PMMA filled with Al2O 3/ZrO2 was carried out in this paper, where the amount of Al 2O3/ZRO2 filler was fixed at 5 wt%.
Abstract: A study on the properties of denture base materials made from PMMA filled with Al2O 3/ZrO2 was carried out. The amount of Al2O 3/ZrO2 filler was fixed at 5 wt%. However, the ratio of Al 2O3 to ZrO2 added was from 0 to 100. Samples were prepared for fracture toughness, flexural, and tensile tests. The fracture surface was analyzed using SEM and EDS. It was found that the Al2O 3/ZrO2 of 80 : 20 ratio shows the highest values of fracture toughness and flexural properties. SEM micrographs indicate that distribution of Al2O3 and ZrO2 in the PMMA matrix is fairly homogeneous. The interface between the reinforcement particles and matrix is good. Therefore, addition of Al2O3/ZrO2 in PMMA improves the mechanical properties of this denture base material.
70 citations
TL;DR: In this article, groundnut shell particles were chemically modified and added to the polymer to form novel bio-based composites and the composites were characterized for some mechanical properties according to ASTM standards.
Abstract: In recent years, there is a growing interest in the use of bio-fibers as reinforcements for thermoplastics and thermosets. A lot of research work has been performed all over the world on the use of natural fibers such as flax, bamboo, sisal, hemp, and jute as reinforcing materials for the preparation of various types of composites. In this study, the agricultural residue such as groundnut shell particles were chemically modified and added to the polymer to form novel bio-based composites. Composite boards were fabricated by randomly distributed groundnut shell particles of different grain sizes and epoxy resin with volume percentages of 70:30, 65:35, and 60:40. The composites prepared were characterized for some mechanical properties according to ASTM standards. The highest tensile strength, tensile modulus, MOR, and impact strength were observed for the sample having groundnut shell particles and epoxy resin proportion 60:40 and 0.5 mm particle size. However, the sample with 60:40 particles and resin pro...
TL;DR: In this article, the impact response of a series of glass fiber reinforced epoxy/aluminum alloy fiber metal laminates has been investigated and the influence of varying target thickness, plate diameter, and impactor radius has been studied and the results compared to those offered by plain composite samples.
Abstract: The low-velocity impact response of a series of glass fiber reinforced epoxy/aluminum alloy fiber metal laminates has been investigated. The influence of varying target thickness, plate diameter, and impactor radius has been studied and the results compared to those offered by plain composite samples. After testing, many samples were sectioned in order to highlight the failure modes under low-velocity impact loading. The FMLs absorbed significant energy in plastic deformation, tearing the metal layers and fiber fracture, and offered a superior impact resistance to the plain composite on which the FMLs were based. The perforation data were normalized by the areal density of the target and the superiority of the metal—composite hybrids remained in evidence. Increasing the target size, the plate thickness, and the indentor diameter resulted in an increase in the energy required to perforate the target. In contrast, impacting the square panels at the corner or along the edge of the target did not have a signi...
TL;DR: In this paper, the authors examined the mechanical behavior of Basalt fiber-reinforced epoxy (BFRE) and a new type of fiber metal laminates (FMLs) composed of steel, aluminum, and BFRE under tensile and bending loads.
Abstract: This article examines the mechanical behavior of Basalt fiber-reinforced epoxy (BFRE) and a new type of fiber metal laminates (FMLs) composed of steel, aluminum, and BFRE named as Basalt fiber metal laminate (BFML) under tensile and bending loads. To study the effect of fillers in epoxy, the micro glass powder (MGP) was only added into the epoxy resin in BFRE composites at various volume fractions. It was found that the MGP had no significant effect on tensile strength, but it raised the stiffness and decreased the failure strain of BFRE. On the other hand, bending strength increased by adding MGP. BFML showed superiority in energy absorption via tensile strength. This FML had flexibility much higher than that of BFRE. Adding MGP or metal layer to basalt-reinforced composites improved the mechanical properties in tensile and bending loads. Selective bending specimens of BFRE are studied by SEM to show the positive role of MGP in raising the bending strength and further analysis of the nature of fracture s...
TL;DR: The results indicated that the UHMWPE composites’ impact toughness was decreased when filled with the basalt fibers, but the strength, hardness, and anti-indentation creep of the UhMW PE composites were improved.
Abstract: In this article, the basalt fibers were used to fill the UHMWPE because of their outstanding mechanical and tribological performances. The UHMWPE composites with the filler content of 5—20 wt.% were prepared. Then, the mechanical and tribological performances of the composites were tested. Also, the wear mechanism was analyzed. The results indicated that the UHMWPE composites’ impact toughness was decreased when filled with the basalt fibers, but the strength, hardness, and anti-indentation creep of the UHMWPE composites were improved. Under the same experimental conditions, the friction coefficient of the UHMWPE composites filled with basalt fibers was decreased to some extent, and the wear loss of the composites was significantly reduced. The analysis showed that the wear type of the UHMWPE composites was changed when filled with the basalt fibers. So, the wear-resistant performance of the UHMWPE composites was effectively enhanced.
TL;DR: In this paper, a bio-based thermoset resin was reinforced with flax fabrics and Lyocell fiber, and the effect of different weave architectures was studied with four different fabrics with different architectures: plain, t...
Abstract: A bio-based thermoset resin was reinforced with flax fabrics and Lyocell fiber. The effect of different weave architectures
was studied with four flax fabrics with different architectures: plain, t ...
TL;DR: In this paper, the effect of nanoclay on short glass fiber (GF)-reinforced polypropylene (PP) composites is examined with special emphasis on the processing, structure, tensile, and wear properties.
Abstract: The effect of nanoclays (0—5 wt%) on short glass fiber (GF)-reinforced polypropylene (PP) composites is examined in this study with special emphasis on the processing, structure, tensile, and wear properties. Addition of nanoclay reduces the melt flow rate of PP and PP—GF composites; however, it improves the crystallization characteristics due to their nucleating effect. This nucleating effect of nanoclay is due to the nanolevel dispersion in polymer matrix and this phenomenon is not observed in the unmodified microclay-filled PP composites. Improved tensile properties are observed in nanoclay-filled PP—GF composites due the intercalated/exfoliated nanocomposite structure. Furthermore, the addition of nanoclay in PP—GF composites improves the wear properties.
TL;DR: In this article, the path toward the delamination-free drilling of glass/epoxy composite material is established using some novel methods based on acoustic emission features, such as sentry function, acoustic emission energy distribution, and acoustic emission count distribution.
Abstract: Control and optimization of machining processes are important issues affecting the development of productivity Monitoring systems have become indispensable in the evaluation of materials during machining In this paper, the path toward the delamination-free drilling of glass/epoxy composite material is established using some novel methods based on acoustic emission features Acoustic emission monitoring with three techniques, sentry function, acoustic emission energy distribution, and acoustic emission count distribution, are developed to detect and realize the critical force at the onset of delamination process on glass/epoxy composite materials The three-point bending test simulates thrust force, the most effective factor in delamination, throughout the process of drilling without backup plate Sentry function is regarded as a new method based on the combination of AE information and mechanical behavior of composite materials The sentry function was used to study the initiation and growth of delamina
TL;DR: In this paper, the authors measured and compared strain energy release rates for laminated composites reinforced by through-thickness stitching using different stitch fiber materials (Carbon, Kevlar, and Vectran).
Abstract: In this study, strain energy release rates are measured and compared for laminated composites reinforced by through-thickness stitching using different stitch fiber materials — Carbon, Kevlar, and Vectran. Strain energy release rates are evaluated experimentally using the DCB test and validated computationally using FEA. The FE model of the stitched composite incorporates a novel four-step stitch fracture process, namely: interfacial debonding, slack absorption, fiber breakage, and pull-out friction. The FE predictions of GIC show good agreement with the experimental results. It is revealed that the relationship between G IC and stitch density, or stitch thread volume fraction for all stitch materials follow a linear law. It is concluded that Vectran provides the toughest interlaminar reinforcement and is most suitable for stitch fiber application. The characterization and difference in fracture behavior between Vectran and Kevlar stitch fibers, by using a novel Interlaminar Tension Test (ITT), are presen...
TL;DR: In this paper, the authors present an experimental study on feasible regions in rotary ultrasonic machining of carbon fiber reinforced plastic (CFRP) using cold air as coolant.
Abstract: Carbon fiber reinforced plastic (CFRP) composites are in demand for a variety of applications due to their superior properties. Drilling is involved in many CFRP applications. Experiments have been successfully conducted to use rotary ultrasonic machining (RUM) for CFRP drilling. These experiments were conducted using either cutting fluids or cold air as coolant. RUM of CFRP composites without cutting fluids can eliminate problems caused by cutting fluids, such as high cost of cutting fluids and their disposal, pollution to the environment, and harm to human health. However, dry machining (machining without cutting fluids) also has its limitations, such as burning of machined surface, more friction and adhesion between tool and workpiece, and reduction in tool life. This article presents an experimental study on feasible regions in rotary ultrasonic machining of CFRP using cold air as coolant. Three criteria (burning of machined surface, delamination, and tool blockage) were used to determine feasible reg...
TL;DR: In this article, the effects of loading levels of nano BN, nano SN and synthetic ND particles on the thermal and mechanical properties of silicone rubber were investigated, and the effect of nano nanoparticles on silicone rubber was investigated.
Abstract: In this study, the effects of loading levels of nano BN, nano SN and synthetic ND particles on the thermal and mechanical properties of silicone rubber were investigated. Nanoparticle-filled silico...
TL;DR: In this article, glass fiber-reinforced polypropylene composites with maleic anhydride grafted polyethylene (MAPP) were compounded with a twin-screw extruder and injection molded.
Abstract: Glass fiber-reinforced PP composites compatibilized with maleic anhydride grafted polypropylene (MAPP) were compounded with a twin-screw extruder and injection molded. The composite specimens were ...
TL;DR: In this paper, a high-shear mechanical mixing technique was used to combine carbon nanotubes in silicone rubber to improve the mechanical properties of the nanocomposites, such as tensile strength, elongation at break, and hardness.
Abstract: MWCNTs reinforced SiR nanocomposites were prepared through a high-shear mechanical mixing technique, using DCP as a curing agent. Under optimum conditions, the MWCNTs can be dispersed homogeneously in the SiR matrix to improve the mechanical properties of the nanocomposites. The mechanical properties of the nanocomposites such as tensile strength, elongation at break, and hardness were evaluated. In addition, the degree of crystallinity and the supercooling were calculated to characterize the crystallization behavior. From DSC study, it has been determined that the degree of crystallinity Xc and the super cooling ΔT, generally characterize the crystallization behavior of the nanocomposites. A decrease in Xc and ΔT indicate that the crystallization rate of the nanococomposites is increased. After pyrolysis, with the increase of CNT content, the decomposition rate or/and the weight loss of the nanocomposites decreased. The dispersion of carbon nanotubes in silicone rubber was characterized by using SEM. Fin...
TL;DR: In this article, the effects of surface treatments on the tensile, flexural, impact strength, and DMA of biocomposites were investigated using 30 wt% kenaf bast fiber (KBF).
Abstract: Biodegradable composites were prepared by melt-blending technique using 30 wt% kenaf bast fiber (KBF) to reinforce 70 wt% plasticized poly(lactic acid) (PLA). The KBF was treated with various percentages of sodium hydroxide (NaOH), whereas 5% triacetin was used as plasticizer. The effects of the KBF surface treatments on the tensile, flexural, impact strength, and DMA of the biocomposites were investigated. Tensile, flexural, and impact testing results reveal that 4% of NaOH-treated KBF produced composites with optimum tensile strength (62 MPa), flexural strength (67 MPa), and the impact strength (42 kJ/m2). The removal of the lignin from the fiber during the surface treatment caused the increment in the modulus result. This finding is also supported by the dynamic mechanical analysis. The storage modulus of plasticized PLA/treated KBF is higher than the storage modulus of plasticized PLA/untreated KBF which is attributed to the enhancement of the fiber—matrix adhesion. The loss modulus results showed tha...
TL;DR: In this paper, the tensile and impact properties of environmental-friendly composites and FMLs have been investigated, and the results suggest that environmental friendly fiber-based FMLs offer significant potential for use in engineering applications.
Abstract: The tensile and impact properties of environmental-friendly composites and FMLs have been investigated. Of the four composites investigated here, a SRPP composite offered superior properties to basalt-, flax-, and hemp fiber-reinforced PP composites. Adding aluminum layers to the outer surfaces of the composites resulted in a significant enhancement in the tensile and impact properties of the laminates. The tensile strength and modulus properties of the FMLs obey a rule of mixtures approach, suggesting that simple procedures can be used to design these hybrid systems. Under low-velocity impact loading, the SRPP, and its associated FML, offered the highest resistance to perforation, as a result of gross plastic deformation in the composite and metal plies. A semi-empirical model, previously employed to characterize metal plates, was used to characterize the low-velocity impact response of the laminates investigated here. The model was capable of predicting the trends in the experimental data with reasonable success. This evidence suggests that environmental-friendly fiber-based FMLs offer significant potential for use in engineering applications.
TL;DR: A parametric experimental study has been conducted to investigate the combined effect of polypropylene fiber and silica fume on the mechanical properties (compressive strength, splitting tensile strength, and compressive modulus of elasticity) of concrete composite containing fly ash.
Abstract: A parametric experimental study has been conducted to investigate the combined effect of polypropylene fiber and silica fume on the mechanical properties (compressive strength, splitting tensile strength, and compressive modulus of elasticity) of concrete composite containing fly ash. Five different fiber volume fractions, four contents of fly ash, and four silica fume contents were used. The results indicate that the contribution of silica fume on the growth of compressive strength and splitting tensile strength is performed at the early curing period, and the contribution of fly ash on the growth of compressive strength and splitting tensile strength is performed at the later curing period, when the fly ash content is not beyond 20% and the silica fume content exceeding 3%. The addition of fly ash and silica fume greatly increases the compressive modulus of elasticity at 28 days curing. Though the addition of polypropylene fiber decreases the compressive strength of the concrete with fly ash and silica ...
TL;DR: In this article, the nano-sized calcium carbonate (CaCO3) is synthesized using an in situ deposition technique and characterized using TEM, the particle size is found to be around 50-60 nm.
Abstract: In this study, the nano-sized calcium carbonate (CaCO3) is synthesized using an in situ deposition technique and characterized using TEM. The particle size is found to be around 50–60 nm. Nanocompo...
TL;DR: In this paper, the effect of silicon carbide and aluminium oxide fillers on tension, flexural, compression, and impact properties of woven jute fabric reinforced epoxy composite has been investigated experimentally.
Abstract: Effect of silicon carbide and aluminium oxide fillers on tension, flexural, compression, and impact properties of woven jute fabric reinforced epoxy composite has been investigated experimentally. Several laminates were prepared by hand lay-up technique by varying the percentage of filler addition. Tests (except impact) were conducted on computer interfaced universal testing machine as per ASTM standards. Impact tests were conducted on pendulum impact testing machine. The results of the tests indicated that addition of filler has significant effect on these properties. Laminate with 10 wt% of filler (based on resin) exhibited the highest properties. The properties were found to decrease beyond 10 wt% of filler loading. The mode of failure was also studied for selected samples using scanning electron microscope.
TL;DR: In this paper, a single-lap joint with a titanium bolt and composite plates was considered, and a numerical model based on FEM was developed to evaluate the stress in both Bolt and Composite plates.
Abstract: This study focuses on the analysis of influence of temperature and bolt torque on aeronautical joint behavior. A single-lap joint, according to ASTM D5961, with a titanium bolt and composite plates was considered. A numerical model based on FEM was developed to evaluate the stress in both bolt and composite plates. Load—displacement curves, stress fields, and induced damage showed, significantly, the influence of temperature combined with torque level on the joint. It was found that in the plate, both maximum and minimum levels of torque considered produced damage above critical threshold. This fact should be accounted for, during the design process of the joint.
TL;DR: In this article, the authors investigated the utilization of tea mill waste fibers (TMWF) in thermoplastic composites and investigated the effects of plastic type and fiber loading rate on mechanical, tensile, and impact properties.
Abstract: The objective of this study was to investigate the utilization of tea mill waste fibers (TMWF) in thermoplastic composites. For this purpose, two plastic types: polypropylene (PP) and high density polyethylene (HDPE), were used as thermoplastic material while TMWF was utilized as a lignocellulosic filler. HDPE or PP and up to 50% TMWF were compounded in the single screw extruder and extrudates were compression molded into thermoplastic composite panels. The effects of plastic type and fiber loading rate on mechanical (flexural, tensile, and impact properties), physical (water absorption and thickness swelling), thermal properties, and morphological of the produced composites were determined. Tensile modulus, flexural modulus, water absorption, and thickness swelling of the produced composites were increased with the rise of the TMWF amount in the thermoplastic matrix. On the other hand, TMWF increase in the thermoplastic matrix reduced the tensile strength, flexural strength, and impact strength of the pr...
TL;DR: In this article, the literature reports based on polystyrene nanocomposites using nanoclay as filler are reviewed and the use of various clay surfactants and different processing conditions, i.e., in situ polymerization, melt intercalation and solution casting, are also reviewed.
Abstract: This article reviews the literature reports based on polystyrene nanocomposites using nanoclay as filler. The use of various clay surfactants and different processing conditions, i.e., in situ polymerization, melt intercalation and solution casting used for the preparation of nanocomposites and its effect on the properties and morphology is also reviewed.