Faculty Publications
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Item With a view to study the response to impacts, epoxy-fly ash systems, with filler particles treated with silane material to their surface were fabricated. The test coupons made from the cured thermoset cast slabs were subjected to impact in an instrumented test set up, where, provision existed for recording both load and total energy absorbed with respect to time. The investigation shows that the crack path shift was highest for unreinforced ones, which, display river marks.(Carl Hanser Verlag, Correlating failure features to impact data in epoxy systems without and with silane surface bearing fly ash filler particles in varying amounts; Korrelation von versagensmerkmalen und schlagzähigkeitsdaten in epoxidsystemen mit und ohne silanbeschichtete flugascheteilchen in unterschiedlichen volumenanteilen) Kishore; Ravikumar, N.L.; Kulkarni, S.M.2004Item Epoxy systems with and without different volume fractions of fly ash particulate fillers are made and their absorption due to immersion in saline water maintained at room temperature are established through weight measurements recorded up to 100h. The 100-h exposed samples are additionally subjected to compression tests to evaluate the strength. The results show that both neat epoxy and fly ash-bearing composites exhibit differing levels of aqueous medium absorption - it being less in ash-free samples. When the ash content in the system is large, the absorption levels are high. The data further revealed that the unexposed samples generally record an increasing strength value with ash content. However, for the exposed cases, a reversal in trend with the ash content is noticed. Attempts to explain these differing trends are made in this work by analyzing the features observed on the surface of compression-failed samples using fractography employing scanning electron microscopy (SEM). © 2005 Sage Publications.(Compression strength of saline water-exposed epoxy system containing fly ash particles) Kishore; Barpanda, P.; Kulkarni, S.M.2005Item Abrasive wear behavior of granite-filled glass-epoxy composites by SiC particles using statistical analysis(2011) Basavarajappa, .S.; Manjunath Yadav, S.M.; Kumar, S.; Arun, K.V.; Narendranath, S.This experimental investigation deals with the evaluation of abrasive wear behavior of Glass Epoxy (G-E) composites on pin-ondisc test rig. A plan of experiments, based on the Taguchi Design of Experiments, was performed to acquire data in controlled way. An orthogonal array and the analysis of variance were employed to investigate the percentage of contribution of various process parameters like sliding speed, applied load, sliding distance and their interactions affecting the abrasive wear volume loss of composites. The correlations between the various factors affecting the abrasive wear behavior of composites were obtained by using multiple linear regression equations. The obtained results indicate that applied load and sliding distance were the wear factors that have the highest physical as well as statistical influence on the abrasive wear behavior of both filled and unfilled G-E composites. A good agreement between the predicted and actual wear resistance was observed within±12%. © Taylor & Francis Group, LLC.Item Role of zirconia filler on friction and dry sliding wear behaviour of bismaleimide nanocomposites(2011) Kurahatti, R.V.; Surendranathan, A.O.; Srivastava, S.; Singh, N.; Ramesh Kumar, A.V.; Suresha, B.This paper discusses the friction and dry sliding wear behaviour of nano-zirconia (nano-ZrO2) filled bismleimide (BMI) composites. Nano-ZrO2 filled BMI composites, containing 0.5, 1, 5 and 10wt.% were prepared using high shear mixer. The influence of these particles on the microhardness, friction and dry sliding wear behaviour were measured with microhardness tester and pin-on-disc wear apparatus. The experimental results indicated that the frictional coefficient and specific wear rate of BMI can be reduced at rather low concentration of nano-ZrO2. The lowest specific wear rate of 4×10-6mm3/Nm was observed for 5wt.% nano-ZrO2 filled composite which is decreased by 78% as compared to the neat BMI. The incorporation of nano-ZrO2 particles leads to an increased hardness of BMI and wear performance of the composites shows good correlation with the hardness up to 5wt.% of filler loading. The results have been supplemented with scanning electron micrographs to help understand the possible wear mechanisms. © 2011 Elsevier Ltd.Item Friction and dry sliding wear behaviour of Ni filled epoxy nanocomposite(2011) Kurahatti, R.V.; Suredranathan, A.O.; Kori, S.A.; Ramesh Kumar, A.V.; Mordina, B.; Mallapur, D.G.Nanosized metal particle filled polymer composites are finding numerous tribological applications in recent years. In the present work, the matrix properties were investigated by introducing nickel nanoparticles (60-100 nm, filler content of 0?5-10 wt-%) into epoxy resin. The influence of these particles on friction and dry sliding wear behaviour was measured using a pin on disc wear set-up. The experimental results indicated that the coefficient of friction and the specific wear rate of epoxy resin can be reduced with a rather low weight fraction of Ni particles. The lowest specific wear rate of 0?6461024 mm3 N21 m21 (compared to neat resin's value of 2?261024 mm3 N21 m21) was observed for composites with the filler content of 0?5 wt-%. The reinforcement of Ni particles leads to improved mechanical properties of the epoxy composites. The results have been supplemented with scanning electron micrographs to help understand the possible wear mechanisms. © 2011 W. S. Maney & Son Ltd.Item Behavior of sandwich beams with functionally graded rubber core in three point bending(2011) Doddamani, M.R.; Kulkarni, S.M.; KishoreThe three-point bending behavior of sandwich beams made up of jute epoxy skins and piecewise linear functionally graded (FG) rubber core reinforced with fly ash filler is investigated. This work studies the influence of the parameters such as weight fraction of fly ash, core to thickness ratio, and orientation of jute on specific bending modulus and strength. The load displacement response of the sandwich is traced to evaluate the specific modulus and strength. FG core samples are prepared by using conventional casting technique and sandwich by hand layup. Presence of gradation is quantified experimentally. Results of bending test indicate that specific modulus and strength are primarily governed by filler content and core to sandwich thickness ratio. FG sandwiches with different gradation configurations (uniform, linear, and piecewise linear) are modeled using finite element analysis (ANSYS 5.4) to evaluate specific strength which is subsequently compared with the experimental results and the best gradation configuration is presented. © 2011 Society of Plastics Engineers.Item Effect of mineral fillers in improving mechanical properties of FKM vulcanizates(2013) Byravan, A.; Bangaragiri, A.Arun Byravan from 3M India, and Anupama Bangaragiri from NITK examine the effect of mineral fillers in improving mechanical properties of FKM vulcanizates. The selection of the formulations is done on the basis of a oil seal application and loading of the mineral fillers is varied to maintain a hardness of around 75 durometer A. Compounds have been press cured at 180°C for 10 minutes and post cured at 230°C for 24 hours to eliminate all the volatiles present in the matrix. The aging study of the compounds reveals that the property loss is within the expected range. This study helps in predicting the behavior of filled vulcanizates at these aging conditions and how the crosslinks of filled compound resist higher temperatures. Tensile loss of highly loaded compounds after aging has been found to be low as compared to the reference compound.Item Use of nano-ATH as a multi-functional additive for poly(ethylene-co-vinyl acetate-co-carbon monoxide)(Springer Verlag service@springer.de, 2014) George, G.; Mahendran, A.; Anandhan, S.Flame retardant aluminum hydroxide (ATH) nanoparticles of size ?10-20 nm were dispersed in ethylene-vinyl acetate-carbon monoxide terpolymer (EVACO) via solution casting. The effect of filler loading on the crystallizability, thermal, mechanical, flammability, optical and electrical properties of EVACO was evaluated. At 1 % filler loading nano-ATH particles exhibited very good dispersibility in the EVACO matrix and the % crystallinity of EVACO is the highest at this filler loading. The changes in crystallinity were studied by X-ray diffractometry and differential scanning calorimetry. The highest tensile strength was observed for the composite with 1 % nano-ATH loading, which has the best filler dispersion, and the decay in the tensile properties at higher filler loading is due to agglomerations of ATH nanoparticles and polymer-filler interface debonding. The UV absorption of these composites is augmented irrespective of the nano-ATH loading and ATH emerges as a good absorber of UV light. The DC electrical conductivity study of the composites proves that the addition nano-ATH is an efficient way to improve the dielectric properties of EVACO. The presence of nano-ATH improves the flame retardance of these composites. © 2014 Springer-Verlag Berlin Heidelberg.Item Influence of redmud on the mechanical, damping and chemical resistance properties of banana/polyester hybrid composites(Elsevier Ltd, 2014) Veerasimman, V.; Marimuthu, M.; Manikandan, V.; Nagarajan, N.; Jeyaraj, P.A novel hybrid composite was developed with the addition of redmud as secondary reinforcing filler with banana fiber reinforced polyester composites (BFRPCs). The effect of varying parameters such as particle size (4, 6 and 13. ?m) and weight percentage (2, 4, 6, 8 and 10. wt%) of redmud were analyzed on static mechanical, free vibration and chemical resistance properties of hybrid composites. The addition of redmud shown enhanced performance compared to the virgin BFRPCs in all the above said properties. The maximum increase of 50% in mechanical strength was observed for the BFRPCs with the addition of redmud having 4. ?m particle size and 8. wt% of filler content compared to pure BFRPCs. The increased value of fundamental natural frequencies with associated modal damping characteristics of redmud filled BFRPCs were found using half-power band width method. All the fabricated composites performed well against various chemicals and it indicates that the resistance to the weight loss is due to the uniformly distributed redmud. To study the effect of redmud on interfacial bonding between the banana fiber and polyester matrix the Scanning Electron Microscope (SEM) image analysis was performed. © 2014 Elsevier Ltd.