Abstract: The demands made on structural composite materials in modern design are increasingly stringent. Greater performance, lower costs, increased reliability and safety all require that the design engineer knows more and more of the material systems available. Bringing together new knowledge contained in constitutive models of continuum design and empirical information from a girth of experience is proving to be difficult because the number of service and process variables required for sophisticated, optimal design is becoming increasingly larger. Understanding Structural Integrity (SI) provides the key to the successful design, certification, and safety of large composite structures and engineering composite materials. This is because SI analysis treats simultaneously the design, the materials used, figures out how best components and parts are joined, and takes service duty into account. But predicting precisely where a crack will develop in a material under stress and exactly when in time catastrophic failure of the structure will occur remains an unsolved mystery.
Abstract: An overview of the recent developments in PA6/PP blend nanocomposites is presented in this paper with an emphasis on their mechanical, thermal and morphological properties. The role of organoclay as a reinforcing agent and polyethylene octene (POE) as an elastomer are discussed in detail. The organoclay increases the strength and stiffness while the POE elastomer increases the impact toughness of the nanocomposites. The effects of various parameters such as PA6/PP blend ratio, organoclay loading and the concentration of elastomer on the nanocomposites properties are also examined. The exfoliated state of organoclay platelets along with the fine particle size and uniform dispersion of POE demonstrate the nanocomposite with improved properties. These materials are attracting considerable interest in polymer research community because they exhibit substantial improvement in properties at low filler contents.
Abstract: Natural fibres offer a number of benefits as reinforcement for synthetic polymers since they have high specific strength and stiffness, high impact strength, biodegradability etc. The aim of this study is to fabricate and determine the performance of unidirectional silk fibre reinforced polymer composites. In the present initial study, alkali treated silk fibres were incorporated as reinforcing agent, while a mixture of 20% maleic anhydride grafted polypropylene (MAPP) and commercial grade polypropylene (PP) was used as matrix element. The unidirectional composites were fabricated by using hot compression machine under specific pressure, temperature and varying fibre loading. Tensile, flexural, impact and hardness tests were carried out by varying silk fibre volume fraction. Composites containing 45% fibre volume fraction had higher tensile and flexural strength, Young’s modulus and flexural modulus compared to other fabricated composites including those with untreated silk fibres. SEM micrographs were taken to examine composite fracture surface and interfacial adhesion between silk fibre and the matrix. These micrographs suggested less fibre pull out and better interfacial bonding for 40% fibre reinforced composites.
Abstract: Fibre reinforced polymer composites play an incredible role in almost all spheres of day to day life and the field of carbon composites is one of the prime research area in recent decade. Polymers are mostly reinforced with fibre or fillers to obtain better mechanical properties. The properties of the polymer composites can be improved largely by varying the type of filler/fibre materials and its volume percentage. Composites properties depend on the size, shape and other physical properties of the reinforcements. A relative easy way to improve the mechanical properties of a polymer is the addition of filler materials. In all particulate filled systems, the adhesion between the matrix and filler plays a significant role in determining the key properties such as strength and toughness. The mechanical properties of composites are also influenced by the filler’s nature, size and distribution profile, aspect ratio, volume fraction, the intrinsic adhesion between the surfaces of filler and polymer. In this paper, the effect of filler material on mechanical properties of E-Glass fibre reinforced polymer has been studied out by varying filler materials. For these study three different types of specimens were prepared, viz FRP without filler material, the FRP with 10 volume percentages of carbon black and the FRP with 10 volume percentage of Fly ash as filler material. The polyester composites were fabricated by hand-layup method. Mechanical properties of the specimens are analyzed using computerized Universal Testing Machine as per ASTM D 638 standards. The resulting behavioral patterns of the FRP with filler material are listed and compared to those of the FRP without filler material. Mechanical properties such as ultimate tensile strength, percentage of elongation, yield strength, Poisson’s ratio and percentage reduction in area were found out.
Abstract: In this study feasibility of using of mixture of bagasse and industrial wood particles for producing single and three layer particleboard . The aim of this study was to consider bagasse as partially substitute particleboard industry raw material. Variables were type of board at two levels (single and three layer), percentage of added bagasse to industrial particles at 4 levels (20%,30%, 40% and 50%) , and press temp. at two levels (165OC and 180 OC ). In producing three layer particleboard wood and bagasse particles were separated and placed in different layers so that bagasse particles were located in the face layers and wood particles were placed in the core of board. But in one layer particleboard bagasse and wood particles were used in the form of mixture. Effect of variables on physical and mechanical properties of particleboard were determined. Results showed that in three layer particleboard physical and mechanical properties were better than single layer particleboard. Increasing press temperature caused improvement in particleboard properties in most cases due to intermeshing and increasing softening wood and bagasse particles. The optimum treatment in this study was found to be adding 50% bagasse and press temperature of 180 OC.
Abstract: A numerical investigation to optimize the carbon/epoxy multi layer composite rotor is performed for the spacecraft energy storage application. A high-speed double and triple layer rotor design is proposed and different composite materials are tested to achieve the most suitable recipe. First, analytical rotor evaluation was performed in order to establish a reliable numerical composite rotor model. Subsequently, finite element analysis is employed in order to optimize the double and triple layer composite rotors. Then, the modal analysis was carried out to determine the rotor natural frequencies. The rotor stress distributions and the rotor mode shapes show that a safe operational regime below 46, 000 rotations per minute is achievable.
Abstract: Electrospinning is direct process to produce polymer fibre with high specific surface area ratio. Apart from polymer fibre producing; electrospinning also can produce a continuous nano size of polymer fibre, which the benefit of this process is the fibre can be produced straight away with lower cost than conventional melt spinning process. Recently, successful attempts have been made to produce polymer fibre by adjusting the parameters of electrospinning such as the collector distance, needle size, polymer concentration voltage applied. From this study, the electrospun fibre was distributed randomly on collector plate surface. The diameter of the fibre produced increase as the polymer concentration was increased. The fibre distribution does not affected by the differ polymer concentrations electrospun, but there were polymer beads formed at the low polymer concentration in solvents. The fiber elongation value is the highest by polymer fiber of 9 wt % while the highest strength is by polymer fiber of 7 wt %. The polymer fibre with low concentration consequently showed the brittle characteristic.
Abstract: Agricultural waste such as sugarcane bagasse is abundant in Malaysia and at present is mainly used as combustible material for energy supply in the sugar factory. This study was conducted to investigate the possibility of manufacturing composite panel from sugarcane bagasse at three density levels (450, 550, 650 kg/m3), two resin content (10 and 12%) and with or without wax (1%) addition. The panel produced were tested for mechanical properties (modulus of elasticity and modulus of rupture) and physical properties (water absorption and thickness swelling) conforming to the British standard (BS EN 310 and BS EN 317). The results revealed that board with density 650kg/m3 gave superior strength compared to those of 450kg/m3 and 550kg/m3 densities. The addition of 1% wax helped to improve the water absorption and thickness swelling of the composite panel. Thus, it can be concluded that composite panel can successfully be produced from sugarcane bagasse as the main source of raw materials.
Abstract: Shortage of solid wood supply as the main raw material for the wood-based industries is cute problem faced by the world wide wood industry. Agricultural residues especially from oil palm plantation are abundantly and is therefore hoped to solve the above problem. In this context, this study would like to venture into the utilization of oil palm frond (OPF) as the potential agricultural residues for the manufacture of biocomposite panel. Raw material (OPF) mixed with the binder urea formaldehyde at three resin levels (8%, 10%, and 12%) to produce board of two density levels (550 kg/m3 and 650 kg/m3). The boards produced were tested for the mechanical strength (MOE & MOR) in accordance with the European Standard (EN 310). The results showed that the MOE values increased as the resin content increased for both board densities. The values are 1755.54 MPa to 2147.44 MPa for 550 kg/m3 and 2351.81 MPa to 2810.34 MPa for 650 kg/m3. Respectively, similar trend of increment was exhibited for the MOR values 12.18 MPa to 14.98 MPa for 550 kg/m3 and 16.62 MPa to 19.90 MPa for 650 kg/m3. In conclusion, the utilization of oil palm frond for the production of strong biocomposite material stands a great potential.