Applied Mechanics and Materials Vol. 895

Abstract: The effect of the fiber orientation of thermosetting polyester resin with carbon and jute fiber-a natural polymer hybrid composite has been investigated by experiments. The tensile, flexural, impact, hardness, specific gravity and three body wear tests. The natural polymer hybrid composite is developed by the traditional method of fabricating the composite i.e. by hand lay-up technique. The proportion by weight of fibers and resin are kept constant, while varying the fiber orientation. The laminates are kept for curing at room temperature condition. Specimens are developed according to ASTM standards. Experimental results showed that hybridization of the composite with natural and synthetic fibers shows enhanced mechanical properties. The content of natural reinforcements is 60% in the developed hybrid composite. The effect of untreated jute placed at different fiber orientation has significant effect on the flexural, impact, hardness and specific gravity properties than tensile properties. The wear property has shown good resistance if the presence of carbon fiber. An overall comparison between the properties of the developed natural polymer hybrid composite revealed that the presence of carbon fiber woven mat on both the sides of the composite has played the critical role by balancing the properties and reducing the overall cost

Abstract: The present investigation is based on fabrication of sisal reinforced high density poly ethylene (HDPE) composites using a novel manufacturing route of microwave processing. Microwave processing was carried out in a multimode applicator at 2.45 GHz with single and multi-layered sisal fibre reinforcement. The comparison between single and multilayered sisal fibre reinforced composites were assessed in terms of tensile, flexural and impact strength. It was found that the multi-layered sisal fibre microwave processed composite has superior properties than single layered reinforced composite. The fractography of tensile fractured surfaces was assessed using electron microscopy. The microwave processed HDPE/sisal composites can be used as a dashboard material of an automobile.

Abstract: Influence of roughness on conventional hydrodynamic lubrication of tilted pad thrust slider bearing is studied. Roughness effect is studied using Christensen stochastic process. To study the effect of roughness, bearing characteristics like load carrying capacity is analyzed.

Abstract: In past few decades, natural fibers which are viable and abundant in nature are the emerging trends in material science as reinforcement for polymer matrix materials and they are the commute for the non-biodegradable, non-renewable and high-density synthetic fibers. Plant-based fibers such as banana, hemp, kenaf, PALF, jute, and coir has been used as reinforcement in a polymer matrix for the applications in consumer goods, furniture’s, civil and automotive structures and low-cost housing structures. The natural fibers used in this study are Hemp and Jute fibers which are finding increasing in the composite material as reinforcements. The main objective of the current work is to examine the mechanical properties of hybrid fibers (hemp and jute) reinforced epoxy composites under room temperature and at cryogenic temperature. From this study, it is clear that tensile, flexural and impact properties of polymer composites are greatly influenced by cryogenic temperature and its properties vary with respect to the extent of cryogenic treatment. The specimens are immersed in liquid nitrogen for the duration of 15, 30, 45 and 60mins and later it is subjected for tensile, flexural and impact properties. The maximum tensile strength of 21.13MPa, flexural strength of 51.95MPa and Impact strength of 8.935kJ/m² is obtained for an untreated specimen and its value start to decrease as curing time increases. At cryogenic temperature, the material comes harder and loses its ductile property and become brittle due differ in thermal expansion coefficient of matrix and fiber material

Abstract: The serious diseases and accidents are the leading causes for the surgeries/transplantation in human body. In present time, a large proportion of world population is facing arthritis problems that lead to partial/total knee arthroplasty and total hip arthroplasty. The implants used in the arthroplasty require high strength, high corrosion and wear resistance and longer life span in a working environment. The quality of fabricated implants significantly depends upon the manufacturing methods used to process the raw materials. In present time, various sintering techniques are popularly used to produced implants owing to improved product quality; however, artificial implant manufacturing industry is looking for more energy efficient, time saving and eco-friendly processing techniques which can offer implants at economical cost along with adequate quality. The present article reviews an overview of different sintering techniques used for producing biomedical implants have been presented. The limitations of these processes have been highlighted and the potential of microwave sintering to address these challenges has been identified. Advantages of using microwave sintering over conventional sintering are also discussed in terms of microstructures, mechanical properties and process efficiency. It has been realized that microwave sintering has potential to cater the needs of the industry for processing of biomaterials as a time saving, energy efficient and environment friendly sintering technique as compare to conventional sintering.

Abstract: Metal matrix composites with aluminium matrix and non-metallic reinforcements are popular candidates in automotive, aerospace, sports and military application because of their high strength-to-weight ratio, stiffness, wear resistance, high-temperature resistance, etc. often they are subjected to secondary manufacturing processes like extrusion, rolling, forging, etc. to suit the service requirements. Metal matrix composites reinforced by nanoparticles are very promising materials, suitable for a large number of applications. In the present investigation, nanocomposites have been synthesized by addition of 0.25, 0.5, 0.75, 1 and 1.25 wt% of nanoAl₂O₃ powder in to molten Al 1100-Mg alloy using stir casting method and then hot forged. The mechanical properties such as tensile strength, hardness and percentage elongations were studied for all the test specimens. The 0.75 wt% of nanoAl₂O₃ added forged nanocomposite exhibited higher hardness and 0.5 wt% of nanoAl₂O₃ added forged nanocomposite exhibited higher yield strength, tensile strength and percentage of elongation.

Abstract: In the present scenario aluminium is an useful metal due its admirable properties such as light weight, low cost and excellent thermal conductivity.In order to take advantages of these properties aluminium is being used to make the metal matrix composites for tribological application, In this present investigation effort has been made to assess the wear properties of Al–B₄C–Gr metal matrix composite at various temperatures such as 323° K, 373° K and 423° K. Al–B₄C–Gr Hybrid metal matrix composites were fabricated by stir casting technique. The influence of parameters like load, speed, distance and temperature on the wear rate was investigated. A plan of experiments, based on Taguchi model with L27 orthogonal array and analysis of variance was employed to investigate the influence of process parameters on the wear behaviour of these hybrid metal matrix composites. The wear resistance increased with increasing temperature, but wear resistance decreased at higher loads. It was observed that the abrasive wear is dominates while sliding as observed by SEM analysis of worn out specimens.

Abstract: The work is focussed on measuring model parameters of a piezoelectric bending energy harvester cantilever beam with sputter coated technique using finite element analysis. The beam was studied for a wide range of frequencies of about 100-1200Hz. The finite element simulation results confirm that the vibrations in the above mentioned frequency range can be effectively utilised to generate energy. Design of electrometrical vibration energy harvester was carried out with literature survey and the effect was analysed for the given length of beam to the voltage produced by the harvester. The Electromagnetic analysis induced voltage is validated with the help of commercial finite element software ANSYS. The simulation results revealed that the effect of sputter coating on the beam will increase the power generation.

Abstract: The aim of this work is to examine the performance, combustion as well as emission characteristics of diesel engine performed for various mixtures of methane-enriched biogas (95% CH₄). Experiments were performed on a single cylinder, four-stroke constant speed, direct injection, water-cooled diesel engine. The engine is operated by means of dual fuel mode using diesel and different mixtures of methane-enriched biogas (BG) like BG10, BG20, BG30, and BG40 mixed with the air (i.e. BG40-40% of CH₄ by volume respectively) for different loads and at injection timing of 27.5° before top dead centre (bTDC). The performance, combustion and emission characteristics of the engine operated by dual fuel mode were experimentally analyzed, and compared with respect to diesel mode. The experimental result reveals that better performance and lower emissions were observed for BG40 compared to other mixtures. The brake thermal efficiency of BG40 is lower by 2.43% compared to diesel at full load. The cylinder peak pressure for dual fuel mode is higher by 6.55% when compared with diesel mode. NOx emission reduced by 2.6 % and CO emission increased by 3.3% compared to diesel at full load respectively. Keywords: Biogas, Energy, Combustion, Emission, Injection timing, dual fuel mode

Abstract: Aluminium Metal Matrix composites (AMC) are known to be very promising light weight materials with enhanced mechanical properties which are used in various industries ^[1]. Aluminium metal–matrix composites reinforced with SiC and Al₂O₃ are used in automotive and aerospace applications due to reduction in weight and increase the engine efficiency and thereby reducing fuel consumption ^[2]. Replacing cast iron engine components with light-weight Al alloys requires overcoming of the poor adhesion and seizure resistance of Aluminium achieved by dispersing SiC, Al₂O₃ or graphite particles in aluminium, Considerable reduction in wear and friction can be achieved by the use of these reinforcement particulate ^[3].