Hybrid Composite Specimens Research Articles

Lateral crashworthiness response of bombyx mori fibre/glass–fibre/epoxy hybrid composite cylindrical tubes-experimental

Experimental studies were undertaken to investigate the effect of reinforced fibre hybridization on the crushing characteristics of quasi-static laterally compressed cylindrical composite tubes. Woven glass fibre (GF) and woven bombyx mori fibre (B.mori) were used as reinforcements and industrial epoxy was used as the matrix material to fabricate the reinforced hybrid composite specimen. Three sets of specimen were fabricated, (1) glass fibre/epoxy (2) B.mori fibre/epoxy and (3) GF/B.mori/epoxy hybrid composite, to clearly ascertain the effect of reinforced fibre hybridization. Load-displacement curves and specimen’s deformation histories were used to analyze energy absorption and load carriability. The length of each specimen was 80 mm, three specimens were tested from each set and an average value recorded. Generally, the results showed that the hybrid composite tube specimen performed better when compared with the other tubes.

Synthesis and mechanical behavior studies of bio-waste derived low-cost composite materials

Abstract Composite materials are the tailor- made multifunctional materials consisting of suitable physical and mechanical properties for the applications in various fields such as aerospace, sensitive electronic equipment, marine, civil construction, etc. In this work, a bio-waste derived composite material was synthesized using compression molding of cashew nut shell liquid (CNSL) (bio-waste resin) along with 3% paraformaldehyde, coconut coir, and sugarcane bagasse. Fibers separated from coconut husk and sugarcane bagasse were collected locally (at Tenali) and used for the synthesis after post-treatment. Those samples were separately treated with 0.1 N NaOH solution for the activation and dried at room temperature before preparation of composite material. Coconut coir, sugarcane fibers, and Cashew nut shell based hybrid composite specimens were tested for tensile strength using Electronic Tensometer. Sugarcane fibers, Coconut coir, and Cashew nut shell resin based hybrid composite exhibited a tensile strength of 11.5 Mpa, 2.6 MPa, and 5.9 MPa, respectively and tensile modulus of the sugarcane fibers, coconut coir and hybrid composite are 4.8 GPa, 0.4 GPa, and 0.5 GPa, respectively. The surface morphology was studied using scanning electron microscopy. The topography of the composite material showed a smooth surface devoid of any morphological features. Further, the composite material will be tested for the suitability of the application.

Actuation of a carbon/epoxy beam using shape memory alloy wires

Shape memory effect of NiTi wires is utilized to design various smart composite structures. In these systems, smart wires can induce strains in the host structure by their inherent shape memory effect and phase transformation at elevated temperatures. This article presents an experimental and numerical study on the actuation capability of shape memory alloy wires embedded in the carbon/epoxy composite. In the experimental part, hybrid shape memory alloy/carbon/epoxy composite specimens are fabricated and examined to measure induced strains in the host structure by the phase transformation of the shape memory alloy wires. Hybrid composite specimens were clamped at one end, and the shape memory alloy wires were activated using electrical resistive heating. Numerical simulations were carried out using ABAQUS software to simulate the actual thermomechanical behavior of the hybrid composite specimens. A three-dimensional finite element model based on cohesive zone modeling is used to predict interfacial debonding in hybrid composite plates. The results of the parametric study suggest that by increasing Young’s modulus of the host composites, the amount of the induced strain decreases rapidly. However, for Young’s moduli more than 20 GPa, the induced strain will stay almost constant. Moreover, it was confirmed that increasing the shape memory alloy pre-strain without controlling the actuation temperature may result in the reduction of induced strain in the host composites.

Hybrid effects on effective mechanical properties of CF/FF and BF/FF epoxy-based composites

The paper explores the synergistic effects due to hybridization of different synthetic reinforcements with flax fibres on the effective mechanical properties of resulted compounds. A commercial epoxy polymer DGEBF is depolyed as embedding material. Accounting for different stacking sequences, from symmetrical to unsymmetrical architectures, the samples were subjected to 3-point bending and their effective mechanical properties retrieved. Positive hybrid effects in the range of 9,5% and 35% for BF/FF and CF/FF architectures, were encountered in the hybrid composite specimens, respectively.

Studies on shape memory alloy-embedded GFRP composites for improved post-impact damage strength

ABSTRACT Embedding shape memory alloys (SMAs) in composites is a promising method resistance against impact loading.In the present paper, an attempt is made to quantify the improvement in damage mitigation properties of FRP (fibre reinforced plastic)composites by embedding SMA.Numerical modelling of low velocity impact was carried out topredict the delamination in composites and composites embedded with SMA and steel wires. Through modelling, effect of location and quantity of SMA material in decreasing the impact induced delamination size was also studied.Compression after impact (CAI) tests were carried out on pristine and SMA hybrid composite (SMAHC)specimens to quantify the change in damage resistance. Experimental results show an improvement in compressive load-carrying capacity after impact in SMAHC as compared to pristine composites.Experimental results match well with numerical findings in terms of; location of placement of SMA wire and optimum quantity of SMA wires.

Mechanical Characterization of Areca husk-Coir fiber reinforced hybrid Composites

Bio fiber based composite materials are gaining interest in the field of certain engineering applications because of their easy processing, low cost, low density and higher strength to weight ratio. In the present study, randomly oriented short Areca Husk and Coir fibers were reinforced with unsaturated polyester resin for the fabrication of composites. The fibers were pretreated with sodium hydroxide to enhance the interphase bonding between the fibers and matrix material. Specimens were prepared and tested for tensile strength, flexural, hardness and impact strength as per respective ASTM standards. The results revealed that individual areca husk fiber reinforced specimens shows improved performance in all properties over coir fiber reinforced specimens. However the hybrid composite specimens test results shows average values as compared to individual fiber reinforced composites.

A Study on Erosion and Mechanical Behavior of Jute/E-Glass Hybrid Composite

Jute/E-Glass reinforced hybrid composite at 30% reinforcement were fabricated using hand lay-up technique. Five different hybrid combinations of Jute and E-glass were tested. It was observed that hybridization of jute/E-glass imparts better mechanical and wear properties than individual fiber reinforced composite. 150% increment observed on tensile properties of hybrid composite specimens. It is concluded that Specific wear tends to increase by increasing load for every specimen. The study of combinations indicates that although the jute based composites exhibit relatively inferior mechanical properties, but when clubbed with E-glass fiber their properties enhanced by manifolds. It further indicates that the incorporation of E-glass fiber results in improvement of erosion wear resistance of Jute/E-Glass fiber composites.

Effects of fibre loading and moisture absorption on the tensile properties of hybrid Napier/glass/epoxy composites

The primary objective of this study was to investigate the effect of moisture absorption on the mechanical degradation of hybrid Napier/glass-epoxy composites. The hybrid Napier/glass-epoxy composites plates were produced by the vacuum infusion method using epoxy resin as a matrix. The hybrid composite specimens were tested after following 50 h of water immersion. The moisture content decreased as the glass fibre content increased. The wet and dry hybrid composite samples were subjected to tensile tests. The incorporation of the glass fibre into the Napier grass fibre-epoxy composites enhanced their tensile strength and tensile modulus. The tensile strength and tensile modulus of the hybrid Napier/glass-epoxy composites (24/6–70 vol%) were 43 MPa and 3.2 GPa, respectively. However, the tensile strength and tensile modulus properties highly degraded under wet conditions.

Effects of stacking sequence on mechanical properties of hybrid composites reinforced with carbon, Kevlar and S-glass fibers

Abstract This study explores the influences of laminates stacking sequence configuration on the mechanical behavior of hybrid composites. The woven carbon, Kevlar and S-glass fibers with epoxy resin were used to produce hybrid composite specimens in addition to full composites. The hybrid specimens were prepared by introducing different fiber volume fractions between carbon/glass, carbon/Kevlar, glass/Kevlar and carbon/glass/Kevlar fibers. Stacking sequence and fibers in outer skin of the laminates obviously showed the effective influence on tensile and flexural strength with modulus. The maximum change in tensile strength due to hybridization effect was achieved with carbon/glass epoxy laminate by replacing the two face sheets of the carbon fibers with glass fibers, resulting in an increase of tensile strength by 60 % according to full carbon/epoxy laminates. On the other hand, flexural strength of glass/Kevlar hybrid laminates showed the highest hybrid effect, resulting in 78 % increase according to full Kevlar/epoxy composites.

Mechanical Behavior of Hybrid Glass/Steel Fiber Reinforced Epoxy Composites.

While conventional fiber-reinforced polymer composites offer high strength and stiffness, they lack ductility and the ability to absorb energy before failure. This work investigates hybrid fiber composites for structural applications comprised of polymer, steel fiber, and glass fibers to address this shortcoming. Varying volume fractions of thin, ductile steel fibers were introduced into glass fiber reinforced epoxy composites. Non-hybrid and hybrid composite specimens were prepared and subjected to monolithic and half-cyclic tensile testing to obtain stress-strain relationships, hysteresis behavior, and insight into failure mechanisms. Open-hole testing was used to assess the vulnerability of the composites to stress concentration. Incorporating steel fibers into glass/epoxy composites offered a significant improvement in energy absorption prior to failure and material re-centering capabilities. It was found that a lower percentage of steel fibers (8.2%) in the hybrid composite outperformed those with higher percentages (15.7% and 22.8%) in terms of energy absorption and re-centering, as the glass reinforcement distributed the plasticity over a larger area. A bilinear hysteresis model was developed to predict cyclic behavior of the hybrid composite.

Mechanical and Dynamic Properties of Hybrid Composite Laminates

Unsaturated polyester-based composites and reinforced with three types of fabrics, E-glass, basalt, and carbon, were fabricated by Hand-Lay Up (HLU) technique at room temperature, with various fiber configuration. Monotonic mechanical properties of hybrid composites laminate such as the tensile, flexural, inter-laminer shear strength and impact strength were investigated. The dynamic response of hybrid laminates composite under pulse load was studied theoretically and experimentally. In the theoretical part, the validity of the theoretical model for evaluating natural frequencies, mode shapes and dynamic response of hybrid composite laminates at various staking sequence has been examined by utilizing of the finite element software (ANSYS). In the experimental part, the response of hybrid composite specimens with various types of fiber configuration and four types of boundary fixations was measured by hammer test technique frequency response function (FRF). The results show that the reinforcement by adding the basalt fabric and carbon fabric based unsaturated polyester composites as a fiber configuration [2C/B/2C]S enhanced the mechanical properties of the hybrid composite laminates among other various stacking sequences. For the stacking sequence [2C/B/2C]S, it was found that the largest values of tensile, flexural strength and interlaminar shear strength (ILSS) were 128.76 MPa, 405 MPa, 20.25 MPa, respectively. The results show the good bonding adhesion at the interface between the fibers and matrix of the hybrid composite laminates. The impact properties with stacking sequences [C-C-G-C-C]s have the largest value at 3.73 Joule as compared with the other composites and stacking sequences of all hybrid composite laminates. Also, the BFRP composites specimen gives the best vibration resistance compared to the other stacking sequences of hybrid composite laminates. The comparison between experimental and numerical model shows the efficiency of the proposed mathematical model of the composite structural specimen with bonded joints.

Fabrication and evaluation of mechanical properties of alkaline treated sisal/hemp fiber reinforced hybrid composite

Fiber reinforced polymer composite have acquired a dominant place in variety of applications because of higher specific strength and modulus, the plant based natural fiber are partially replacing currently used synthetic fiber as reinforcement for polymer composites. In this research work going to develop a new material which posses a strength to weight ratio that for exceed any of the present material. The hybrid composite sisal/hemp reinforced with epoxy matrix has been developed by compression moulding technique according to ASTM standards. Sodium hydroxide (NAOH) was used as alkali for treating the fibers. The amount of reinforcement was varied from 10% to 50% in steps of 10%. Prepared specimens were examined for mechanical properties such as tensile strength, flexural strength, and hardness. Hybrid composite with 40wt% sisal/hemp fiber were found to posses higher strength (tensile strength = 53.13Mpa and flexural strength = 82.07Mpa) among the fabricated hybrid composite specimens. Hardness value increases with increasing the fiber volume. Morphological examinations are carried out to analyze the interfacial characteristics, internal structure and fractured surfaces by using scanning electron microscope.

Mechanical Properties of Sisal/Coir Fiber Reinforced Hybrid Composites Fabricated by Cold Pressing Method

Bio-composites have less density and are environmental friendly materials that require less energy during production and subsequent machining. This paper reports the mechanical and water absorption properties of sodium hydroxide (NaOH) treated sisal and coir fiber reinforced epoxy resin thermo set hybrid composites. The hybrid composites were prepared by traditional cold pressing method at room temperature with applied pressure of 410.4 kg/cm2 for 3 hours pressurization time. The mechanical properties were characterized according to ASTM standards. Hybrid composites with 40wt% of sisal and coir fiber were found to possess higher tensile strength of 48.2MPa and flexural strength of 76.68 MPa among the fabricated hybrid composite specimens. Absorption of water increases with increasing fiber volume. The experimental result also show that the sisal and coir fibers are promising reinforcement for use in low cost bio-composites which have high strength to weight ratio.

High strain-rate failure in carbon/Kevlar hybrid woven composites via a novel SHPB-AE coupled test

Abstract The high strain-rate induced failure characteristics in a carbon/Kevlar hybrid composite subjected to high strain-rate compressive loading were studied using a novel SHPB-AE coupled test. The tests were performed based on a split-Hopkinson pressure bar (SHPB) apparatus and an acoustic emission (AE) technique, respectively. Within the strain-rate range of 1002–1941 s −1 , a high strain-rate compressive test was conducted on the cylindrical carbon/Kevlar hybrid composite specimens located between the incident and transmitted bars. A wide bandwidth type AE sensor was connected to the specimen with a fine copper waveguide to monitor the AE signals in real time during the test. Specific types of failure mechanisms were observed with optical microscopy and scanning electron microscopy. First, AE characteristics originating from the specimens were investigated profoundly to distinguish the AE signals from diverse damage or failure sources. AE signals were then analyzed in terms of the AE amplitude, the AE count, the slope of cumulative AE count and the peak frequency. Finally, signals were classified into four types based on the waveform and corresponding peak frequency by a short time Fourier transforms (STFT). As a result, under high strain-rate compressive loading, the strain level at the damage initiation was shortened with increasing strain-rate. The failure process of the carbon/Kevlar hybrid woven composite showed initial matrix fracture and then brittle carbon fiber breakage. Subsequently, multiple failure mechanisms appeared, such as fiber-matrix debonding, fiber pull-out, excessive deformation and breakage in the Kevlar fiber tips including splitting and fibrillation. The application of the novel SHPB-AE coupled test to the carbon/Kevlar hybrid composite was discussed in depth for characterizing the failure process, and it was an effective and relevant methodology to grasp in situ information on the failures under high strain-rate compressive loading.

Moisture absorption and mechanical degradation of hybrid Pennisetum purpureum/glass–epoxy composites

The effect of moisture absorption on the mechanical degradation of hybrid Pennisetum purpureum/glass–epoxy composites was investigated. The hybrid P. purpureum/glass–epoxy composites plates were manufactured by the vacuum infusion method using epoxy resin as a matrix. Following 50h of water immersion, the hybrid composite specimens were tested. The moisture content reduced as the glass fibre content increased. The wet and dry hybrid composite specimens were subjected to tensile and flexural tests. The incorporation of the glass fibre into the P. purpureum–epoxy composites enhanced their tensile and flexural strength, as well as their modulus. The tensile and flexural strengths of the hybrid P. purpureum/glass–epoxy composites (24/6–70vol%) were 43 and 60MPa, respectively. However, the tensile and flexural properties significantly degraded under wet conditions. Using field emission scanning electron microscopy (FESEM), morphological analysis was performed to observe the fracture behaviour of the specimens and the effect of water molecules.

Friction Stir Processing and Mechanical Testing of SiC-Al2O3 and B4C-Al2O3 Particulates Reinforced Aluminium Alloy Composites

This paper details the friction stir processing (FSP) and mechanical behaviour of hybrid composite materials. Boron carbide (B4C), silicon carbide (SiC), aluminium oxide (Al2O3) particulates are reinforced with aluminium alloy (LM25) to fabricate hybrid composite specimens via FSP. The effect of FSP parameters such as tool rotational speed, traversing speed, groove width and micro hardness was investigated. Scanning electron microscopy analysis has shown that B4C, SiC and Al2O3 particulates are dispersed well into the Aluminium alloy matrix. Mechanical test results have shown that the tensile strength and Vickers hardness of FSP aluminium alloy with B4C and Al2O3 particulates are better than FSP aluminium alloy with SiC and Al2O3 particulates.

Analisis Perbandingan Metode Pengujian Kekasaran Permukaan pada Material Polimer Dan Komposit - Review

The development of composite materials can be combined with the test material to obtain a composite material properties such as strength, hardness, wear, and surface roughness. The surface roughness of polymeric materials and composites can be tested in many ways, ranging from tactile method (profile measurement), focus variation (area measurement), fringe projection (area measurement), confocal laser scanning microscope (area measurement), and several other methods. Varied roughness testing on the surface will be compared to obtain the most suitable testing method to obtain the roughness of hybrid composite and composite ceramic specimens. The method used in this study is literature review. For hybrid composite material will be less suitable when using tactile method because of hybrid composite having a lower surface hardness. Additionally hybrid composite has a porosity value greater than the ceramic composite. This causes hybrid composite is more rugged than ceramic composite. Therefore with greater porosity will be suitable when using the roughness measurement with a microscope device such as fringe projection (area measurement), and confocal laser scanning microscope (area measurement).

Investigations on Mechanical Behaviour of B4C and MoS2 Reinforced AA2024 Hybrid Composites

AbstractThe results of an experimental investigation of the mechanical properties of boron carbide (B4C) and molybdenum disulphide (MoS2) reinforced aluminium alloy (AA2024) hybrid composite samples, processed by stir casting process are reported in this paper. Based on the previous studies, it was concluded that for 4% of weight of the B4C powders reinforced in AA2024 metal matrix have better mechanical properties like tensile strength and hardness than the base alloy. Also the 4% of MoS2 reinforced in AA2024 metal matrix exhibited good mechanical properties than the matrix metal. Hence an attempt has been made to further improve the properties of the composite using both B4C and MoS2 as reinforcement particles in the AA2024 matrix. in the present study hybrid composite specimen were developed varying the weight% of B4C and MoS2, viz., 1%+3%, 2%+2%, 3%+1% B4C and MoS2 respectively in the AA2024 matrix. The prepared samples were subjected to a series of mechanical tests like tensile and hardness tests. Further, SEM & XRD analyses were performed on the prepared samples to study the microstructure and to ensure the proper dispersion of the reinforced particles in the metal matrix.

Effects of Mass Ratio of Phenolic Fiber to Quartz Fiber on the Ablative Properties of Hybrid Fabric Reinforced Composites

Phenolic-quartz hybrid fabric reinforced phenolic resin composites were fabricated by compression molding and the mass ratios of phenolic fiber to quartz fiber were 1:3, 1:1 and 3:1, respectively. The ablative properties of the composite specimens were quantitatively evaluated by oxyacetylene flame test and exhaust plume ablative test with a small liquid motor (EPSLM). The effects of mass ratio of phenolic fiber to quartz fiber on the ablative properties of the composites were investigated. In the oxyacetylene flame test, the mass loss rate of the composite specimens, which can be predicted by the mixture rule, increased with rising content of phenolic fiber. However, the mixture rule was not applicable to predict the mass loss of the composite specimen in EPSLM. The mass loss of the hybrid composite specimens decreased with increasing content of phenolic fiber. As suggested by the patterns and microstructures of the char after ablation, it is useful to stabilize the char by adding phenolic fiber, and the resistance of the hybrid composite specimens to heat-flow erosion was evidently augmented when the mass ratio of phenolic fiber to quartz fiber was higher than 1:1.

Tensile behavior of aluminum/carbon fiber reinforced polymer hybrid composites at intermediate strain rates

Tensile behaviors of aluminum/carbon fiber reinforced polymer hybrid composites with different carbon fiber reinforced polymer stacking sequences were measured at strain rates between 0.001/s and 100/s and properties of the hybrid composites were compared to the results of aluminum and carbon fiber reinforced polymer tested under the same conditions. In the aluminum specimen, negative strain rate sensitivity resulted in a significant decrease in the tensile strength and positive strain rate sensitivity resulted in an increase in failure strain at higher strain rates. However, in the hybrid composite specimen, both the tensile strength and the failure strain could be increased as the strain rate increased by reinforcing the aluminum with carbon fiber reinforced polymer. The differences in tensile properties and the degree of strain rate sensitivity were extensive depending on the stacking sequence of the carbon fiber reinforced polymer layer. A Weibull function with scale parameter σ0 and shape parameter β was used in order to describe the relation between stress and strain of aluminum/carbon fiber reinforced polymer hybrid composites, and the constitutive equation established by the Weibull function described the tensile behavior of the hybrid composites very well.