通过关键词查论文: Hybrid Composite


作者: Chinnakurli Suryanarayana Ramesh, Nirupama Mohan, Vikram K.S. Jain, Harsha R. Gudi
摘要: In recent years, Al6061-carbon fiber composites are gaining wide spread popularity as they find scope in certain high-tech applications such as automobile, aerospace, transport, andprocessing industries. Thesecomposites possess high strength to weight ratio, excellent wear resistance in addition to superior mechanical properties. The experimental method of determining wear phenomenon of the developed composites is an expensive as well as a tedious process.As such engineers and scientists are focusing their attention towards developing mathematical modelsfor determining wear phenomenon. The use of mathematical modeling for prediction of wear phenomenon is an evolving research area. Hence, meager information is available as regards the mathematical model to determine wear rate of composites. Mathematical modeling is slowly gaining impetus in industries in order to assess the life of sliding components and establishing the economic loss incurred due to the wear phenomenon. In the light of the above, Al6061 carbon fiber composites were prepared by liquid metallurgical route and then machined to a standard size of pin.On the pins, sliding wear test was conducted on a pin-on-disc apparatus using C-45 steel disc as per ASTM Standard. Data generated was then used in developing AdaptiveNeuro Fuzzy Inference System (ANFIS). The ANFIS logic was created using the fuzzy logic tool box of Matlab 7.10 Version. For simulating, actual working conditions used to establish the sliding wear behaviour of Al6061-xwt%Carbon fiber composites (x=5, 10) including variable parameters such as Varying load (from 10-60N in step of 10N), Sliding distance, Weight fraction (5-10%) keeping other parameters constant such as track diameter 20 mm, Speed 500rpm and Pin diameter 8 mm were used.The adopted fuzzy model employs hybrid learning techniques for updating the premise and consequent parameter. The predicted values of sliding wear rate of Al6061-xwt% carbon fiber are in close agreement with the experimental results.
作者: C.S. Ramesh, M.L. Shreeshail, Harsha R. Gudi, Khan Zulfiqar
摘要: Currently, the focus in materials development is on processing of hybrid metal matrix composites (MMCs) in particular aluminum (Al) based owing to their flexibility in achieving tailor made properties. Till date, only processing, characterization of mechanical and adhesive wear behavior of various hybrid MMCs have received much attention. However, solid erosion wear of hybrid MMCs has not yet been reported. This assessment will further enlarge the range of applications of hybrid MMCs in particular for components in operation for military applications especially in desert areas. In the light of the above, the present paper discusses the air jet erosion behavior of developed Al6061-SiC-carbon fibre hybrid composite prepared by combination of powder metallurgy and casting process followed by hot extrusion at temperature of 550°C using extrusion ratio of 1:4. The solid sand erodent particle size used was 312 μm while the operating pressure and velocity was maintained at 1.4 bar and 30 m/sec respectively. The adopted feed rate of the sand particles was 2.0 g/min with standoff distance being 10 mm. The sample size was 25 mm x 25 mm x 10 mm. The effect of silicon carbide (SiC), Carbon fibre (Cf), test duration and angle of impingement of the erodent on the erosion wear loss of the developed hybrid composite will be discussed at length.
作者: S.W. Jung, Jae Hyup Lee, Jae Bok Nam, H.W. Nam, Kyung Seop Han
作者: B. Boukert, A. Benkhedda, S. Bergheul
摘要: In recent years composite materials are widely used in the aerospace industry. The advantages of these materials are derived from their high strength, rigidity and lightness. More importantly, they have the potential to reduce the cost of construction, while improving structural reliability and increasing safety. Aircraft structural parts made of composite materials with polymeric matrix, subject to variables conditions and severe environments, require a good knowledge of their behavior under humidity and temperature. The matrix is very sensitive to these parameters. A degradation of properties is then observed [1-1.
作者: Shazed Md. Aziz, Suraya Abdul Rashid, Saeed Rahmanian, Mohamad Amran Mohd Salleh
摘要: Growing carbon nanotubes (CNT) on the surface of high performance carbon fibers (CF) offers a means to tailor the mechanical properties of the fiber-matrix interface of a composite. In the context of this work, a floating catalyst chemical vapor deposition (CVD) unit was utilized to grow CNT onto the surface of CF. The surface and mechanical properties of the resultant fibers, CNT density and alignment morphology were explained to depend on the CNT growth temperature, growth time, and atmospheric conditions within the CVD chamber. Single fiber/Epoxy composite coupons were fabricated by using both neat and CNT-coated CF to conduct single fiber fragmentation test (SFFT). It was observed that the coating of CNT onto CF surface improves the IFSS between CF and matrix when compared with neat-CF. Particularly, CF treatment condition for CNT-coating with 700 °C reaction temperature and 30 minutes reaction time has shown a considerable increase in IFSS approximately of 45% over that of the untreated fiber from which it was processed. The fiber-matrix adhesion was analyzed by using SEM on cryogenically fractured surface of both types of composites. The proper justification of fiber-matrix adhesion featured by composite interfacial properties was explained through IFSS.
作者: Kumar Jayachandran Nirmal, D. Premkumar
摘要: An experimental analysis has been carried out to investigate the mechanical properties of composites reinforced by sisal, coir, and banana fibres into epoxy resin matrix. The natural fibres were extracted by retting and manual processes. The composites fabricated by epoxy resin and reinforcement in the hybrid combination of Sisal-Banana and Sisal-Coir with the volume fraction of fibres varying from 5% to 30%. It has been identified that the mechanical properties increase with the increase of volume fraction of fibres to a certain extent and then decreases. The hybridization of the reinforcement in the composite shows greater mechanical properties when compared to individual type of natural fibres reinforced. For all the composites tested, the tensile strength of the composite increased up to 25% of volume fraction of the fibres and further for the increase in the volume fraction of fibre the mechanical properties were decreased. As same as tensile properties, the flexural and impact strength also increased linearly up to 25% of volume fraction of fibres and further for the increase in the volume fraction of fibre the mechanical properties were slightly decreased. Key Words: Sisal, Banana, Coir, Epoxy, Hybrid composite.
作者: Ali Nawaz Mengal, Saravanan Karuppanan, Azmi Abdul Wahab
摘要: Wind turbine blades are the major structural element and highest cost component in the wind power system. Modern wind turbine blade sizes are increasing, and the driving motivation behind this is to increase the efficiency and energy output per unit rotor area, and to reduce the cost per kilowatt hour. However due to the increase in size the material selection for wind turbine has become critical and complex. To achieve the desired materials to improve the design of wind turbine blades several factors such as high fatigue strength, less weight, less cost and potential of recycling must be focused. Basalt fiber is a relative newcomer to fiber reinforced polymers and structural composites. Basalt fiber with their excellent mechanical properties represents an interesting alternative composite material for modern wind turbine blades. Some manufacturers claim that basalt fiber has similar or better properties than S-2 glass fiber and its cheaper than carbon fiber. Basalt fiber together with carbon fiber are the most advanced and interesting area of hybrid technologies. This paper reviews extra ordinary properties of basalt fiber over other fiber reinforced composites and highlight how the basalt special properties together with carbon fiber will reduce the weight and cost of wind turbine blades while improving their performance. This paper also demonstrates why the basalt carbon hybrid composite material will be an ideal alternative for the wind turbine rotor blades.
作者: I.D.G Ary Subagia, Leonard D. Tijing, Yon Jig Kim
摘要: This study investigated the influence of electrospun polyurethane mats containing different contents of carbon nanotubes (CNTs) stacked in between basalt fabric layers to form a composite laminate. The composite laminate was fabricated using a vacuum-assisted resin transfer molding (VARTM) process. Flexural test were carried out to investigate the strength and stiffness of composites for each configuration, while the failure characteristics were observed using a field emission scanning electron microscopy (FESEM) analysis. The results showed that flexural strength and stiffness of the hybrid composites with increasing CNT content in polyurethane (PU) nanofiber were increased by 6.5% and 17.3%, respectively. Furthermore, the addition of surfactants for the dispersion of CNTs in nanofibers significantly improved the flexural property of the composite interply basalt fabric-CNT/PU laminates. This study proved that the use of multi-scale reinforcement fillers with good and homogeneous dispersion increased the mechanical performance of the composite.
作者: P. Shanmughasundaram, R. Subramanian, M. MahendraBoopathi
摘要: Metal Matrix Composites (MMCs) have emerged as a potential material especially for automotive and aerospace industries. In view of the growing engineering applications of these composites, the machining parameters have to be optimized in order to attain good surface quality, reduced tool wear and cutting forces. In this paper, the influences of the feed and step drill’s geometries such as step angle and step size on the exit burr height have been investigated for burr minimization in drilling of MMCs. Experimental study was conducted for Al-15wt.% fly ash composites and Al-15wt.% fly ash /1.5wt.% graphite hybrid composites which are fabricated through stir casting method. Optimum drilling parameters were identified for burr minimization by the application of Taguchi method, analysis of variance (ANOVA) and the results were validated by confirmation test. Results revealed that feed and step drill’s geometries step angle and step size were the most influential factors on the formation of burr. Dynamom¬eter was employed to measure the thrust that was being applied to the work piece when it was drilled. The inclusion of graphite as supplementary reinforcement in Al / fly ash reinforced composite reduces the thrust force and exit burr height considerably.
作者: Benjamin Lehmann, Sathis Kumar Selvarayan, Ravand Ghomeshi, Götz T. Gresser
摘要: Carbon fiber reinforced plastic (CFRP) was integrated with steel fibers in order to improve the toughness and to enhance the structural integrity during crash. An epoxy system with internal mold release was chosen as the matrix system. The surface modification of steel fibers was done by sandblasting and twisting in order to improve the fiber-matrix adhesion through mechanical interlocking mechanism. The pull-out test of surface modified steel fiber doubled the adhesive strength. The steel fiber integration increased the maximum bending stress of the composites up to 20% whereas the elongation at break reduced to 2.3%. The energy dissipation factor of the steel fiber integrated CFRPs was also reduced compared to CFRPs without steel fiber. An increase in fracture toughness was observed for the CFRPs with steel fibers that amounts to 17 J.