Hybrid Composites

Pultrusion manufacturing process is a well established technique for the cost-effective production of high-modulus and lightweight composite materials having constant cross-sectional profiles. A study was carried out to analyze the effect of additives on bending strength of pultruded hybrid reinforced resol type phenolic composite. Glassfibre roving and kenaf fibre hybrid were reinforced in resol type phenolic. A series of bending tests were performed by varying the loading percentage of two type's pultruded fibres,without additives and with additives. From the results, it was found that the modulus of strength of composites with additives display higher values as compared to composite without additives. The presence of additives were able to synergistically interact with both fibres and finally improve the interaction between them. Analysis of the fracture surface from the bending test were carried out using Dino-Lite digital microscope.

Aluminium Magnesium alloys reveals several specific and attractive properties that qualify them to be used in many
automotive and aeronautical applications. Aluminium matrix composites have good mechanical and physical properties, when
reinforced with flyash and Graphite particles. In the present work, the number of cast samples of Al6Mg /flyash/Graphite
composites was prepared by using stir casting followed by hot rolling. The percentage inclusions is fixed for 2%fly ash and
varied Graphite from 2 to 6wt%. The composites prepared with a stirring speed of 400 rpm and stir casted at 7400C. Wear
resistance is superior for higher percentage of reinforcement with increase in pull out of rolling. Higher weight percentage of
reinforcements with higher reduction results in shrinkage cavities and particle cracking during rolling

In this work, dry sliding wear properties of Al 7075 Al 7075+ 5 wt.% SiC, Al7075 + 5 wt.% SiC + X wt.% graphite (X=5-10) hybrid nano-composites were developed by the principle of powdered metallurgy (P / M). Al 7075 hybrid nano-composites are highly promising materials that would be desirable for a wide range of applications. Under dry sliding conditions, the tests were carried out on a pin-on-disk machine was used to assess the loss of wear on base metal, composite and hybrid composites were calculated by different normal loads (5–20 N), and sliding speeds (0.5 – 2 m/s) and sliding distances (500–2000 m). Micro-structural examination of base metal and composites were investigated using an Optical Microscope (OM) and scanning electron microscope (SEM). The hybrid nano-composites revealed those greatest improvements in tribological results with 5 wt. % Silicon Carbide and 10 wt. % Graphite. Main wearing mechanism for hybrid composite materials has been established to form lubricating layer on both the surface and specimen. From experimental outcomes, it has been found that wear resistance tends to increase as weight percentage of the reinforcement increases.

Oil palm trunk (OPT) is a solid waste obtained in large quantities after the felling of oil palm trees and is available year-round. Scientists and industrialists face difficulties in utilizing these solid wastes for different applications due to great variations in their physical and mechanical properties. Because OPT consists of lignocellulosic materials, its cellulosic material is utilized in the production of panel products such as particleboard, medium density fibreboard, mineral-bonded particleboard, block board, and cement board. In order to control the OPT waste, it is essential to consider its alternative utilization inside buildings as lightweight construction materials and furniture. The impregnation of different resins in wood and non-wood materials can improve the quality of the OPT, making it possible to utilize OPT as raw materials for different applications. The enhanced properties and good appearance of impregnated OPT have found use in high-grade furniture and housing materials. In order to further evaluate its potential, this review has been compiled for the detailed study of various properties, characteristics, and applications of OPT.

In this work Hybrid Metal Matrix Composite have been developed using stir casting process for improving
the Wear Behavior at lower cost. The silicon carbide (SiC) as one of the reinforcement used with 3%
weight fraction and Alumina (Al2O3) as the major reinforcement in 3%,6%,9% &12% weight fraction. Al-
7075 has been considered as the matrix material .The low cost stir casting process has been used for the
development of the composite system. The matrix material was melted in electric furnace and the heat
treated reinforcement in the desired weight fraction have been added followed by constant stirring the melt.
The temperature of the melt held at 750°C. The pouring temperature was recorded which has relation to
quality of the casting. The cast specimens have been obtained in the form of cylindrical rod of 20mm
diameter and 200mm length for carrying out tribological tests. Microstructure analysis reveals the uniform
distribution of reinforcements in the aluminum matrix. The density of the composite increases with the
increase in weight fraction. The composite density found to lie in between the density range of matrix and
the reinforcement. The pin on disc wear test has been carried on all the samples at various speeds of
300,600,900 and 1200 rpm, varying load of 1kg, 2kg, 3kg & 4kg and varying sliding distances of 1km, 2km,
3km & 4km. These test reveals that the wear resistance increases with the increase in the reinforcement
weight fraction. The increase in the speed reduces the wear rate and wear rate increases in with increase
in sliding distance. The wear rate and coefficient of the composite reduces for higher volume fraction. The
addition of SiC apart from improving the wear rate reduces the noise and vibration at higher speed and
load condition. The overall tribological property increases due to addition of the two reinforcement.

The Flexural, Impact properties and Scanning electron microscope analysis of Bamboo/glass fibers Reinforced polyester Hybrid composites were studied. The effect of alkali treatment of the bamboo fibers on these properties was also studied. It was observed that the Flexural, impact properties of the hybrid composite increase with glass fiber content. These properties found to be higher when alkali treated bamboo fibers were used in the hybrid composites. The elimination of amorphous hemi-cellulose with alkali treated leading to higher crystallinity of the bamboo fibers with alkali treatment may be responsible for these observations. The author investigated the interfacial bonding between Glass/Bamboo reinforced polyester composites. The effect of alkali treatment on the bonding between Glass/Bamboo composites was also studied.

This paper focused on experimental study of hybrid composite specimens prepared according to ASTM standards. Composites are the formed by the combination of reinforcement and matrix, which exibits better properties compared to that of individual components. Because of its low density characteristics, composites has got a wide range of applications. Composites are classified mainly as natural and artificial ones depending on the type of reinforcement used. The cost of artificial ones are quite higher compared to natural ones, but because of their better strength, corrosion resistance and less maintenance requirements they are mostly preferred. The specimens are prepared by means of hand lay-up process considering ASTM D 3039 and ASTM 790 standards. UTM tensile load test as well as flexure (3 point bending) tests are conducted on the prepared specimen. From the results, better material is selected for further applications.

Composites are one of the most widely used materials because of their adaptability to different situations and the relative ease of combination with other materials to serve specific purposes and exhibit desirable properties. Various composites like metal matrix composites, nano composites, fiber reinforced composites and hybrid composites are commonly used in various industries. Hybrid composite and metal matrix composites materials have extensive engineering application where strength to weight ratio, low cost and ease of fabrication are required. The investigation of the novel applications of hybrid composites has been of deep interest to the researchers for many years as evident from reports. This paper presents a study on the applications of hybrid composites in different types of industries like automobile a industry, aviation industry, structural applications, orthopedics aids and some other applications because of their advanced properties.  Some recently developed hybrid composites and their mechanical properties and applications also discussed in this paper.

The polymer matrix composites have been widely used for many applications. These are light in weight and easy for
manufacturing. The hybrid fiber reinforced composites have been prepared to enhance the mechanical, thermal, damping
properties compared to single-fiber reinforced composites. The fiber reinforced hybrid composites consist of two or
more fiber in a matrix system. The different fibers were reinforced with suitable matrix for preparing the hybrid
composites using various manufacturing methodology. The hybrid composites are used for many application and replacing
wood, wood fiber composites and conventional materials. The mechanical properties (tensile, flexural and impact),
dynamic, tribological and water absorption properties of natural fiber reinforced hybrid polymer composites and natural/
synthetic fiber reinforced hybrid polymer composites were reported.

The physico-mechanical properties of lignocellulosic kenaf fiber reinforced polyvinyl alcohol (PVA) biocomposite films were investigated. To improve the properties of the biocomposite, kenaf fibers were chemically treated separately in a single stage (with Cr-2(SO4)(3)center dot 12(H2O)) and double stages (with CrSO4 and NaHCO3) to improve the adhesion and compatibility between the kenaf fiber and PVA matrix. PVA was reinforced with various compositions of chemically treated kenaf fiber by using a solution casting technique. Microstructural analyses and mechanical tests were subsequently conducted. Scanning electron microscopic analysis indicated that chemical treatment improved the uniformity distribution of kenaf fiber within the PVA matrix. FTIR and XRD analyses confirmed the presence of chromium on the fiber surface. The tensile strength of PVA reinforced with chemical treated kenaf fiber was found to be higher than those reinforced with untreated kenaf. The Young's modulus, flexural strength, and flexural modulus increased with fiber loading for both untreated and treated kenaf fiber reinforced PVA films. The double stage treated kenaf fiber showed better mechanical properties and lower moisture uptake than the single stage treated kenaf fiber.

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Strict requirements that are put on mechanical constructions from the aspect of increase of exploitation periods and reduction of their weights, therefore of
their prices as well, implicate developments and applications of new composite materials with matrices of lightweight metals. Composite materials with
metal matrices are used for engine cylinders, pistons, disc and drum brakes, Cardan shafts and for other elements in automotive and aviation industry. The
most important type of metallic materials is composite materials with matrices of aluminium alloys due to a set of their beneficial properties. Improvement
of mechanical, especially tribological properties of hybrid composites were provided by the use of certain reinforce materials such as SiC, Al2O3 and
graphite in defined weight or volumetric share. New developed hybrid composites with aluminium matrices have significantly higher resistance to wear,
higher specific stiffness and higher resistance to fatigue. By the increase of quantities of produced elements made of hybrid composites, decrease of their
prices is induced that even further enlarge their applications. The applications of aluminium hybrid composites are considered from the aspect and with
the focus on automotive industry

Natural–synthetic fiber hybrid composites offer a combination of high mechanical properties from the synthetic fibers and the advantages of renewable fibers to produce a material with highly specific and determined properties. In this study, plain-woven kenaf/glass reinforced unsaturated polyester (UP) hybrid composites were fabricated using the hand lay-up method with a cold hydraulic press in a sandwich-configuration laminate. The glass was used as a shell with kenaf as a core, with an approximate total fiber content of 40%. Three glass/kenaf weight ratios percentages of (70/30)% (H1), (55/45)% (H2), and (30/70)% (H3) were used to fabricate hybrid composites. Also pure glass/UP and kenaf/UP were fabricated for comparison purposes. Monotonic tests, namely tensile, compression, and flexural strengths of the composites, were performed. The morphological properties of tensile and compression failure of kenaf and hybrid composites were studied. In addition, uniaxial tensile fatigue life of hybrid composites were conducted and evaluated. The results revealed that the hybrid composite (H1) offered a good balance and the best static properties, but in tensile fatigue loading (H3) displayed low fatigue sensitivity when compared with the other hybrid composites.

The low-velocity impact behaviour of hybrid laminates reinforced with woven aramid and basalt fabrics
and manufactured byresin transfer moulding was studied.Specimens with different stacking sequences
were tested atthree different energies,namely 5,12.5 and 25J.Residual post-impact properties ofthe
different configurations ofaramid/basalt hybrid laminates were characterized byquasi static four point
bending tests.Post-impact flexuraltests have been monitored using acoustic emission inorder toget fur-
ther information on failure mechanisms.Results indicate that hybrid laminates with intercalated config-
uration (alternatingsequence ofbasalt and aramid fabrics)have better impact energy absorption
capability and enhanced damage toleranc ewith respect tothe all- aramid laminates,while basalt and
hybrid laminates with sandwich-like configuration (sevenbasalt fabric layers atthe centre ofthe lami-
nate as core and three aramid fabric layers for each side ofthe composite asskins)present the most
favou rable flexuralbehaviour.

Composites have been widely used in applications where there is a risk of impact, due to the excellent
properties these materials display for absorbing impact energy. However, composites during impact
situations typically generate an enormous number of small pieces, due to the energy absorption
mechanism of these materials, a mechanism which does not include plastic deformation. This can prove
dangerous in sports competitions, where the small fragments of the original structure may harm
competitors.
This study was designed to explore the possibility of incorporating a material which, whilst maintaining
a high level of energy absorption without any plastic deformation mechanism, was able to
maintain its original form, or at least significantly reduce the number of pieces generated after impact.
The addition of a polyamide layer, NOMEX®, to a monolithic fabric laminate was investigated in this
paper. The process of fabrication is described and the different properties of the material under
consideration: interlaminar fracture toughness energy (GIC), indentation (id) and delamination after
impact (Ai) and compression after impact (sCAI), were measured and compared with those of the original
monolithic fabric.

In this paper, fabrication of hybrid composites reinforced with sisal and glass fibers is treated form and are mixed in the proposition 1:1 in order to reinforce in epoxy resign. Mechanical properties viz., tensile, compressive and hardness are studied to assess the influence of fiber lengths such as 10,20 and 30 mm. The variations of aforementioned properties on hybrid composites with different fiber lengths have been studied. Thermal properties such as Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) are studied to investigate the influence of change in fiber length on treated and untreated hybrid composites. Significant improvement in tensile, hardness and compressive strengths of sisal/glass hybrid composites has been observed by the alkali treatments. In TGA investigation 3 o C rise in decomposition temperature, 4 o Crise for glass transition temperature is considered for DSC analysis.

Civil and military structures, such as helicopters, aircrafts, navies, tanks or buildings are susceptible to blast loads as terroristic attacks increases, therefore there is the need to design blast resistant structures. During an explosion the peak pressure produced by shock wave is much greater than the static collapse pressure. Metallic structures usually undergo large plastic deformations absorbing blast energy before reaching equilibrium. Due to their high specific properties, fibre-reinforced polymers are being considered for energy absorption applications in blast resistant armours. A deep insight into the relationship between explosion loads, composite architecture and deformation/fracture behaviour will offer the possibility to design structures with significantly enhanced energy absorption and blast resistance performance. This study presents the results of a numerical investigation aimed at understanding the performance of a hybrid composite (glass/carbon fibre) plate subjected to blast loads using commercial LS-DYNA software. In particular, the paper deals with numerical 3D simulations of damages caused by air blast waves generated by C4 charges on two fully clamped rectangular plates made of steel and hybrid (S2/Carbon) composite, respectively. A Multi Materials Arbitrary Lagrangian Eulerian (MMALE) formulation was used to simulate the shock phenomenon. The simulation results are presented and compared with the experimental data.

In the present work, the natural composites based on sugarcane bagasse fiber and/or coconut shell powder were processed using hand lay-up technique. The matrix selected was polyester. Three different types of composites were considered: polyester matrix ? sugarcane fiber, polyester matrix ? sugarcane fiber ? metal mesh and polyester matrix ? sugarcane fiber ? coconut shell filler. The sugarcane fibers were used in three forms: (1) chemically treated by NaOH, (2) chemically treated by HCl, and (3) untreated condition. In total, 9 types of composites were developed and studied for tensile, flexural and impact properties. The fracture surface of the tensile and flexural test samples was examined with the aid of scanning electron microscope to understand the bonding characteristics and the mode of failure. The key-findings from the present work are: (1) the composites reinforced with the NaOH treated sugarcane fiber and the metal mesh show superior tensile and impact properties whereas the composites reinforced with the NaOH treated sugarcane fiber show the best flexural properties, (2) NaOH treatment of sugarcane fibres has a significant effect in improving the mechanical properties by surface modification of fibres through OH-functional groups. In contrast, HCl treatment of sugarcane deteriorates the surface of the sugarcane by absorbing the electrons. The damaged surface results in weak bonding causing poor mechanical properties, (3) From the SEM analysis of the surface of the sugarcane fiber, it may be concluded that the surface condition of the sugarcane fibres decide the bonding with the matrix. The fiber pull-outs and porosities are less in the NaOH treated sugarcane reinforced composites. The fiber failure is the main mechanism of failure in the tensile test whereas the fiber debonding from the matrix is the main source of failure in the flexural test.

This feasibility study investigates the flexural properties of biocomposites containing woven flax textiles (plain, twill, satin) and woven twill patterned hybrid textiles containing flax-/glass or flax-/carbon mixture for lightweight applications. Synthetic fibers are integrated as weft and flax fibers are integrated as warp yarns using a double-rapier weaving machine with a Jacquard attachment. The corresponding biocomposites are manufactured via vacuum infusion process using a biobased epoxy resin as a matrix. The manufactured biocomposites are analyzed with regard to their density and flexural properties. The results show that the use of hybrid textiles offers a promising solution for the manufacture of biocomposites with a higher biobased content and significantly improved flexural properties. Furthermore, the introduction of high-performance synthetic fibers in textiles enables the manufacture of biocomposites with an isotropic mechanical performance.

Investigation of tribological behaviour of the hybrid composite, whose substrate is Al/Si alloy A356, reinforced with 10 wt. (%) of silicon carbide (SiC) and 0 and 5 wt. (%) of graphite (Gr) is presented in this paper by application of the Taguchi method. The composites are obtained by the compocasting procedure. The tribological investigations were realised on the tribometer with the block-on-disc contact pair in lubricating conditions and for the two values of the sliding speed, 0.25 and 1 m/s, two values of load 40 and 120 N and two values of the sliding path, 1200 and 2400 m. The wear traces were measured within the experiment, namely the wear intensities were calculated and results analysis was performed by application of the ANOVA technique. The strongest influence on the wear intensity was exhibited by the normal load (39.05%), then follow wt. (%) of the reinforcer (26.84%), the sliding speed (20.93%) and the sliding path (10.72%). The smallest wear appears in hybrid composite Al/SiC/Gr with 5 wt. (%) of the graphite reinforces, at the lowest load of 40 N, sliding speed of 1 m/s and along the sliding path of 2400 m. The main aim of their study is to provide new information and knowledge about the tribological behaviour of hybrid composites with a base of Al-Si alloy A356 reinforced with 10 wt. (%) SiC and with the addition of 0 and 5 wt.% Gr under lubricated sliding conditions.

In this work Hybrid Metal Matrix Composite have been developed using stir casting process for improving
the Wear Behavior at lower cost. The silicon carbide (SiC) as one of the reinforcement used with 3%
weight fraction and Alumina (Al2O3) as the major reinforcement in 3%,6%,9% &12% weight fraction. Al-
7075 has been considered as the matrix material .The low cost stir casting process has been used for the
development of the composite system. The matrix material was melted in electric furnace and the heat
treated reinforcement in the desired weight fraction have been added followed by constant stirring the melt.
The temperature of the melt held at 750°C. The pouring temperature was recorded which has relation to
quality of the casting. The cast specimens have been obtained in the form of cylindrical rod of 20mm
diameter and 200mm length for carrying out tribological tests. Microstructure analysis reveals the uniform
distribution of reinforcements in the aluminum matrix. The density of the composite increases with the
increase in weight fraction. The composite density found to lie in between the density range of matrix and
the reinforcement. The pin on disc wear test has been carried on all the samples at various speeds of
300,600,900 and 1200 rpm, varying load of 1kg, 2kg, 3kg & 4kg and varying sliding distances of 1km, 2km,
3km & 4km. These test reveals that the wear resistance increases with the increase in the reinforcement
weight fraction. The increase in the speed reduces the wear rate and wear rate increases in with increase
in sliding distance. The wear rate and coefficient of the composite reduces for higher volume fraction. The
addition of SiC apart from improving the wear rate reduces the noise and vibration at higher speed and
load condition. The overall tribological property increases due to addition of the two reinforcement.

In this work, mechanical and tribological behaviour of AA7075/Al2O3/graphite
hybrid composite was studied. Pin-on-disc machine was used for the conductance
of the wear test. The composites with 2–8 wt.% Al2O3 particles were processed
by conventional liquid casting method. For the hybrid composite, 5 wt.% graphite
were commonly added to the base alloy. The hardness of the composites was measured
using a Vickers hardness tester and their tensile strength was measured by
an universal testing machine (UTM). Scanning electron microscopy (SEM) was
used to analyse worn surfaces of samples. It was found that an increase in Al2O3
content reduced the coefficient of friction up to 6 wt.% and thereon slightly increased.
But this effect was reverse in hybrid composites and AA 7075 / Graphite
composites. Hardness and tensile strength of composites increased with increasing
Al2O3 content in both cases. The wear rates for both composites and hybrid
composites were dependent on Al2O3 content in the alloy. Al/Al2O3 composites
containing 6 wt.% Al2O3 exhibited superior wear properties over the base alloy,
and hybrid composites

In the present study, the Al2219, Al2219/ B 4 C & Al2219/B 4 C/MoS 2 hybrid composites are investigated under dry sliding wear test as for ASTM G 99-95 standard. Al 2219 base matrix reinforced with B 4 C & mixture of B 4 C and MoS 2 are fabricated using stir casting technique. By using pin on disc apparatus the test was conducted by taking parameters like sliding distance, sliding velocity and loads. The result reveals that the addition of B 4 C slightly reduces wear rate of composites, further B 4 C and MoS 2 reinforcement decreases the wear rate of the hybrid composites and increases the wear resistance of the composites. The wear rate decreases with increasing the % of MoS 2 . At a lower sliding velocity the wear rate decreases and as the sliding velocity increases the wear rate increases. As the sliding distances and load increases the wear rate drastically increases.

Hybrid natural fiber composites made from the combination of natural fiber and synthetic fiber offers the performance solution while in the same time able to provide further balance between cost and sustainability requirements for automotive structural application. Despite such advantages, the task of designing such hybrid composites during materials selection process such as for matrix materials selection are very challenging considering the involvement of multiple conflicting requirements with varying attributes which are needed to be complied simultaneously by the candidate material. In this paper, multi-criteria decision making technique (MCDM) through the integration of Analytic Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method were applied in the materials selection of thermoplastic matrix for hybrid natural fiber composites formulation towards the design of automotive parking brake lever component. Based on literature review, four major types of automotive thermoplastic materials used for passenger car were selected as the materials candidate namely high density polyethylene, low density polyethylene, polypropylene and nylon 6. Moreover, four (4) main design criteria and ten (10) sub-criteria were applied in the selection process based on the product design specifications. The AHP method was first utilized to analyze the weightage of each criteria with respect to the goal and TOPSIS method was later applied to determine the best solution among the thermoplastic material candidates. The overall score shows that polypropylene is the most suitable thermoplastic matrix material for the hybrid natural fiber composites formulation for the intended application. The integrated AHP-TOPSIS method was also found able to provide systematic comparison and selection method to composites designers especially for automotive product development purposes involving hybrid natural fiber composites.

Oil palm trunk (OPT) is a solid waste obtained in large quantities after the felling of oil palm trees and is available year-round. Scientists and industrialists face difficulties in utilizing these solid wastes for different applications due to great variations in their physical and mechanical properties. Because OPT consists of lignocellulosic materials, its cellulosic material is utilized in the production of panel products such as particleboard, medium density fibreboard, mineral-bonded particleboard, block board, and cement board. In order to control the OPT waste, it is essential to consider its alternative utilization inside buildings as lightweight construction materials and furniture. The impregnation of different resins in wood and non-wood materials can improve the quality of the OPT, making it possible to utilize OPT as raw materials for different applications. The enhanced properties and good appearance of impregnated OPT have found use in high-grade furniture and housing materials. In order to further evaluate its potential, this review has been compiled for the detailed study of various properties, characteristics, and applications of OPT.

The aim of this work is to investigate the effect of hybridization of kenaf-glass fibers reinforced unsaturated polyester on fatigue life. Three types of composites were fabricated using hands lay-up method, namely, kenaf, glass, and hybrid composites with 30% of weight fraction, the hybrid was mixed with a ratio of kenaf: glass 10:20. Monotonic tests were achieved (Tensile and compression) to determine the fatigue stress levels. Fully reversed fatigue loading was conducted with a stress ratio of -1 and stress levels 55-85 % of the ultimate static stresses, all tests were conducted at 10 Hz of frequency. The results proof a positive hybrid composite; also agree with the rule of mixture that can predict the final composite properties. Moreover, it’s been observed an improvement in overall mechanical properties of hybrid compared to individual ones.

Civil and military structures, such as helicopters, aircrafts, naval ships, tanks or buildings are susceptible to blast loads as terroristic attacks increases, therefore there is the need to design blast resistant structures. During an explosion the peak pressure produced by shock wave is much greater than the static collapse pressure. Metallic structures usually undergo large plastic deformations absorbing blast energy before reaching equilibrium. Due to their high specific properties, fibre-reinforced polymers are being considered for energy absorption applications in blast resistant armours. A deep insight into the relationship between explosion loads, composite architecture and deformation/fracture behaviour will offer the possibility to design structures with significantly enhanced energy absorption and blast resistance performance. This study presents the results of a numerical investigation aimed at understanding the performance of a hybrid composite (glass/carbon fibre) plate subjected to blast loads using commercial LS-DYNA software. In particular, the paper deals with numerical 3D simulations of damages caused by air blast waves generated by C4 charges on two fully clamped rectangular plates made of steel and hybrid (S2/Carbon) composite, respectively. A Multi Materials Arbitrary Lagrangian Eulerian (MMALE) formulation was used to simulate the shock phenomenon. For the steel plates, the Johnson-Cook material model was employed. For the composite plates both in-plane and out-of-plane failure criteria were employed. In particular, a contact tiebreak formulation with a mixed mode failure criteria was employed to simulate delamination failure. As for the steel plates the results showed that excellent correlation with the experimental data for the two blast load conditions in terms of dynamic and residual deflection for two different C4 charges. For the composite plates the numerical results showed that, as expected, a wider delamination damage was observed for the higher blast loads case. Widespread tensile matrix damage was experienced for both blast load cases, while only for 875 g blast load fiber failure damage was observed. This agrees well with the experimental data showing that the composite panel was not able to resist to the 875 g blast load.

Laminated hybrid composites were prepared by incorporating dry bamboo strips and oil palm trunk veneer (OPTV) to form five-layer laminated composites. Two different species of bamboo were used including Dendrocalamus asper and Gigantochloa levis to explore their potential for furniture manufacturing. Influence of the bamboo species along with the different arrangements of lamination on the physical, mechanical and morphology properties of the hybrid laminated composites were investigated via scanning electron microscope (SEM), density, water absorption (WA), thickness swelling (TS) as well as impact and hardness strength test. Morphological study showed that filling up of surface cavity by adhesive improved the bonding strength between the surfaces of the bamboo strips and OPTV in the laminated hybrid composites. Additionally, different layer arrangements affected the mechanical properties, i.e., perpendicular arrangement exhibited higher strength compared to the parallel arrangement for both hardness and impact strength. The species of bamboo did not show significant impact on the density for different layer arrangements. Thus, test results clearly indicated that bamboo strips and OPTV hybrid composites could be used as an alternative to wood-based composites for furniture manufacturing.

The aim of this study is to investigate the effect of alkali and SLS (Sodium Lauryl Sulphate) treatment on Banana/Kenaf Hybrid composites and woven hybrid composites. The fibers are treated with 10% of sodium hydroxide (NaOH) and 10% Sodium Lauryl Sulfate (SLS) for 30 minutes. Woven banana and kenaf fiber reinforced unsaturated polyester (USP) composites were fabricated by moulding technique. The fiber content in the composite is kept constant to 40 %. The variation in the Mechanical properties (Tensile, Flexure and Impact strength) and morphological changes are studied.

In this investigation, the dynamic mechanical properties of Indian almond –
Kenaf fiber composite were investigated and the effect of stacking
sequence was analyzed. Four types of composites viz. kenaf, Kenaf/
Indian almond/Kenaf, Indian almond/Kenaf/Indian almond, and Indian
almond were fabricated by hand layup technique. The experimental
results revealed that the kenaf fiber composite showed the superior
storage modulus and loss modulus values compared to all other composites

due to the high stiffness of kenaf fiber and better bonding between
the matrix and fiber. Among hybrid composites, Kenaf/Indian almond/
Kenaf composite displayed a greater storage modulus and loss modulus
than Indian almond/Kenaf/Indian almond composite due to the presence
of two layers of high stiffness kenaf fiber. Further, the order of thermal
stability of the composites was observed as: Kenaf > Kenaf/Indian almond/
Kenaf > Indian almond/Kenaf/Indian almond > Indian almond. In addition,
the Indian almond fiber composite and Indian almond/Kenaf/Indian
almond composite exhibited good damping properties than other composites

owing to the more mobility of polymer chain. Cole – cole plot
showed that the structure of all the fabricated composites was heterogeneous

in nature and kenaf fiber composite displayed the higher heterogeneity

among all other materials. Moreover, the modeling of storage
modulus and damping factor was performed and compared with the
experimental results. The results showed good agreement with the theoretical

and experimental values.

The fracture toughness and strength of materials are
adversely affected by the cracks in the materials,
which can be induced during manufacturing, assembly,
and usage. In this study, the effect of crack length and
crack location on the fracture toughness of woven
glass and carbon reinforced hybrid and non-hybrid
composite plates were investigated experimentally and
numerically. For this purpose, glass/epoxy (G8), and
carbon/epoxy (C8) non-hybrid composite plates and
glass-carbon/epoxy (G2C4G2), and carbon-glass/epoxy
(C2G4C2) hybrid composite plates were produced by
using hand lay-up method. The fracture toughness of
hybrid and non-hybrid composite plates having three
different crack locations as single edge crack (SEC),
center crack (CC), and double edge crack (DEC) with
different crack lengths were obtained by determining
failure loads under tensile loading. The ANSYS finite
element package program was used in order to determine
the fracture toughness of hybrid and non-hybrid
composites by means of J-Integral methods. The
results showed that the highest and the lowest fracture
toughness values were obtained in the specimens
with SEC and CC, respectively.

This work investigated the influence of fly ash and sic on the wear behavior of Al 7072,5 and 10 wt. % of hybrid composites. Research reveals the effectiveness of incorporating Sic into the compound to obtain reduced wear. The Al 7072 reinforced with sic-fly ash were investigated. The composites were fabricated using the under-stir casting route. Ceramic particles along with solid lubricating materials were incorporated into an aluminum alloy matrix to accomplish a reduction in both wear resistance and enhance the coefficient of friction. The Al 7072/fly ash/sic hybrid composite was prepared with 5,and 10 wt. % of sic /fly ash particles. It was observed the stress on pin in composites was good compared to the matrix alloy. And it was evident from the SEM microstructures that no particle was cracked or pulled out from the matrix. This was due to a good interfacial bond between the alloy and the matrix. These findings suggest that a hybrid composite system gives better wear-resistant properties.

The influence of silane treated aluminum oxide (Al 2 O 3) and molybdenum disulphide (MoS 2) microfillers on three-body abrasive wear behaviour of carbon fabric reinforced epoxy (C-E) composites was evaluated using a rubber wheel abrasion tester. Three-body wear tests were conducted at different loads/abrading distances. The experimental results showed that the wear volume increased with increasing abrading dis-tance/load while the specific wear rate decreased with increasing abrading distance. It was found that silane treated aluminum oxide (Al 2 O 3) and molybdenum disulphide (MoS 2) as fillers enhanced the abrasion resistance of the C-E composites. Further, the specific wear rate depends on applied load, the type of filler and filler loading. The factorial design was carried out to investigate the effects of individual operating parameters like normal load, abrading distance, type of filler and filler loading and the combined effect of these same parameters, and their interactions with the contact surfaces, on the wear of C-E composites. It was found that the combined effect of operating parameters and their interactions with the contact surfaces had a profound influence on the wear of these composites. The worn surface morphology was performed to investigate the wear mechanisms involved during abrasion process.

composites with different volume fractions of fiber up to 0.7 using micromechanical approach. Two ways for calculating the material properties, that is, analytical and numerical approaches, were presented. In numerical approach, finite element analysis was used
to evaluate the elastic modulus and thermal conductivity of composite from the constituent material properties.The finite element
model based on three-dimensional micromechanical representative volume element (RVE) with a square and hexagonal packing
geometry was implemented by using finite element code ANSYS. Circular cross section of fiber and square cross section of fiber were considered to develop RVE. The periodic boundary conditions are applied to the RVE to calculate elastic modulus of composite. The steady state heat transfer simulations were performed in thermal analysis to calculate thermal conductivity of composite. In analytical approach, the elastic modulus is calculated by rule of mixture, Halpin-Tsai model, and periodic microstructure. Thermal
conductivity is calculated analytically by using rule of mixture, the Chawla model, and the Hashin model. The material properties
obtained using finite element techniques were compared with different analytical methods and good agreement was achieved. The results are affected by a number of parameters such as volume fraction of the fibers, geometry of fiber, and RVE.

The aim of this study is to investigate the effect of alkali and SLS (Sodium Lauryl Sulphate) treatment on Banana/Kenaf Hybrid composites and woven hybrid composites. The fibers are treated with 10% of sodium hydroxide (NaOH) and 10% Sodium Lauryl Sulfate (SLS) for 30 minutes. Woven banana and kenaf fiber reinforced unsaturated polyester (USP) composites were fabricated by moulding technique. The fiber content in the composite is kept constant to 40 %. The variation in the Mechanical properties (Tensile, Flexure and Impact strength) and morphological changes are studied.

word count: 250 Word count (Introduction-References): 5927 Abstract Background: Intramedullary nails are the primary choice for treating long bone fractures. However, there are still complications following nail surgery including non-union, delayed union, and fracture of the bone or the implant. Reducing nail stiffness while still maintaining sufficient stability seems to be the ideal solution to overcome the abovementioned complications. Methods: In this study, a new hybrid concept for nails made of carbon fibres/flax/epoxy was developed in order to reduce stress shielding. The mechanical performance of this new implant in terms of fracture stability and load sharing was assessed using a comprehensive non-linear finite element model. The proposed model considers several mechanical factors in nine fracture configurations at immediately post-operative, and in the healed bone stages. Results: The post-operative results showed that the hybrid composite nail increases the average normal force at the fracture site by 319.23N (P<0.05), and the mean stress in the vicinity of fracture by 2.11MPa (P <0.05) at 45% gait cycle, while only a 0.33mm and 0.39mm (P<0.05)

Plate and shell analysis using classical plate theory (CPT) has a lack of accuracy in predicting the influence of transverse deformation, because of its assumption that the line normal to the surface remains straight and normal to the midplane before and after deformation. The next revision by constant shear deformation theory or famous as first order shear deformation theory (CSDT/FOSDT) still suffers a disadvantage that has a constant value in the shear term that is called shear locking phenomenon. This matter has been corrected by higher order shear deformation theory (HOSDT) using a refined assumption that the line normal to the surface should be in a parabolic function and not normal to the midplane, but normal to the surfaces so that it fulfills the zero strain in the surface. The analysis of the bending part of laminated composite flat shell element is applied by higher order lamination theory (HOLT) that is adopted from HOSDT. This model is accurate for thicknesses variation and complex materials. HOLT model is implemented into finite element procedure to find deflection, stresses and internal forces. It can be concluded that the displacement and stresses in HOLT model are higher than FOLT the ones (first order lamination theory) in small ratio of a/h dan its result almost the same value for a/h ratio more than 10. In a square plate case, the displacement gets smaller if the fiber arranged into cross-ply sequence. Interlaminar stresses along the thickness is not distributed continuously, but they have certain modes that depend on the depth of point position, the lamina or layer number, fiber orthotropic angle of each layer and a/h ratio.

Numerous research studies are carried out in order to investigate various properties and implement the potential of hybrid carbon/flax composites for technical applications. This review aims to present a summary of materials and manufacturing techniques, which are currently used for the fabrication of the carbon/flax composites, and describe the reported tensile, bending, impact, and damping properties of the resulting hybrid materials as well as the attempts to model some of these properties.

Polv mer composites are prominent miterials for numerous industrial applications
and they are utilized for bearings, rollers, seals, gears, cams, wheels and clutches.
These materials are subjected to wear and much of the research carried out to
understand wear behaviour and improvement in the wear resistance. A pin—on-disc
setup (Magnum Engineers, Ban galore) was used for wear experiments. The Results of
wear properties of vinyl ester-Glass fibre composites by van’ing filler percentages of
the chosen fillers Ti02, A ‘203 and MoS2 for study and were presented in the present
paper. The main objective is to determine the optimum input parameters, those will
give minimum specific wear rate and min imnum wear volume and these are considered
as output responses. Effects of input parameters such as, type of filler, percentage of
filler, load and sliding distance on the output responses are studied. As per Taguchi
orthogonal array of 127, experiments have been conducted on viny! ester/GF miano
composites on Pin on Disk apparatus. Experimental anal sis was conducted. The
results were chosen based on the choices yielded by the design of experiments and
optimized for the better output responses using Taguchi method by plotting inaili effect
plots for SN ratio and means. From the plots it is observed that, Titan iumnl oxide fillerwith 7.5% for load of 29.43N at sliding distance of 1059.80m yielded optimum wear
resistance and minimum wear volume loss.

Screw withdrawal and flexural strength were evaluated for Dendrocalamus asper and Gigantochloa levis bamboo species to explore the possibility of their use as structural material in place of wood. Dry bamboo strips and 4-mm-thick oil palm trunk veneer (OPTV) were processed into thin laminates and hot-pressed using urea formaldehyde resin to produce bamboo-OPTV hybrid biocomposites. Bamboo furniture is far more resistant to damage than traditional hardwoods. Bamboo is even used in cutting boards for this reason. Even though there have been some reports on the mechanical enhancement of the bamboo-based composites, so far there has been no comprehensive study on the screw pulling and flexural strength of bamboo-based hybrid composites. The results revealed a stronger correlation of the bamboo hybrid under screw withdrawal and flexural strength, but there was a weaker correlation in the mechanical properties of the bamboo hybrid due to the random selection of laminate from different bamboo species. Furthermore, test results clearly showed that bamboo-OPTV hybrid biocomposites can be used as an alternative to wood and wood-based composites for furniture applications.

The low-velocity impact response of a range of fiber metal laminate (FML) panels was investigated through testing and finite element simulations. The objective of this study was to understand the impact-damage resistance of these novel composites, so that they can be designed optimally for impact-resistant aircraft applications. The FML panels were made up of aluminum alloy 7475 T761 and unidirectional S2 glass/epoxy oriented in a cross-ply configuration. Experimental tests were performed using a free-fall drop dart testing machine. The plate specimens were constrained on a circular edge by the clamping fixture. The shape and the nature of the damage inflicted by impact were evaluated using both destructive cross-sectional microphotography and nondestructive ultrasonic techniques. The tests showed that FML laminates are capable of absorbing energy through localized plastic deformation and through failure at the interface between the layers. In particular, delaminations occurred in the back face of the aluminum-alloy sheet and its adjacent fiber-reinforced epoxy layer and in between adjacent fiber-reinforced epoxy layer. The finite element code, LS-DYNA3D, was used to perform numerical simulations of low-velocity impact to predict the complex damage propagations. The computed post-impact deformed shapes and damage patterns were found to be fairly close to experimental results.

The aim of this study is to investigate the effect of alkali and SLS (Sodium Lauryl Sulphate) treatment on Banana/Kenaf Hybrid composites and woven hybrid composites. The fibers are treated with 10% of sodium hydroxide (NaOH) and 10% Sodium Lauryl Sulfate (SLS) for 30 minutes. Woven banana and kenaf fiber reinforced unsaturated polyester (USP) composites were fabricated by moulding technique. The fiber content in the composite is kept constant to 40 %. The variation in the Mechanical properties (Tensile, Flexure and Impact strength) and morphological changes are studied.