Browsing by Author "Kishore"

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Behavior of sandwich beams with functionally graded rubber core in three point bending
(2011) Doddamani, M.; Kulkarni, S.M.; Kishore
The 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.
Behavior of sandwich beams with functionally graded rubber core in three point bending
(2011) Doddamani, M.R.; Kulkarni, S.M.; Kishore
The 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.
Compression strength of aqueous media exposed epoxy system containing silane surface bearing fly ash particles
(2004) Kishore; Ravikumar, N.L.; Kulkarni, S.M.
Neat epoxy (NE) and epoxy system with different volume fractions of fly ash fillers with their surfaces treated by silane bearing material were made and the responses to exposure by immersion in varying aqueous media, such as plain water (PW), seawater (SW) and seawater containing small amount of dilute hydrochloric acid (SWA) maintained at 80 C, established through weight measurements recorded up to 100 h on the test coupons. Further on, the 100 h exposed samples were subjected to compression tests to evaluate the strength. The results showed that both NE and the silane treated ash bearing composites generally exhibited the highest water absorption in SWA case and the lowest in SW media, with the water absorption level for PW case falling in between. When the ash content in the composite is very large, the water absorption levels tend to be lower for both SW and SWA. The data further showed that unexposed samples recorded less strength compared to the exposed ones. In the case of exposed samples, in all the media employed, as the ash content increases the strength also increases. Further, it was noticed that the samples exposed to SW showed higher strength than the corresponding values noticed with SWA case. Lower strength was found in samples immersed in PW case. Attempts to explain these differing trends are made in this effort by analyzing the features observed on the surface of compression failed samples using fractography technique employing scanning electron microscope (SEM).
Compression strength of saline water-exposed epoxy system containing fly ash particles
(2005) Kishore; Barpanda, P.; Kulkarni, S.M.
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.
Compressive and flexural properties of functionally graded fly ash cenosphere-epoxy resin syntactic foams
(2015) Doddamani, M.; Kishore; Shunmugasamy, V.C.; Gupta, N.; Vijayakumar, H.B.
The present study focuses on developing functionally graded syntactic foams (FGSFs) based on a layered co-curing technique. The FGSFs were characterized for compressive and flexural properties and compared with plain syntactic foams. The results showed that the specific compressive modulus was 3-67% higher in FGSFs compared to plain syntactic foams. FGSF exhibited 5-34% and 34-87% higher specific modulus and strength, respectively in flexural mode. The microscopic examinations of comparative responses of the filler and matrix to deformation suggest that the failure is dominated by the matrix. The gradient in the composition of syntactic foams helps in effectively distributing the stress throughout the microstructure and results in improved mechanical performance of syntactic foams. From the microscopy studies, it is evident that, the failure mechanism in the FGSF under flexural loading is governed by a crack that initiated on the tensile side of the specimen and propagated through the thickness to cause complete fracture. The microscopic observations further clearly demonstrate the existence of seamless interfaces between the layers and a clear difference in the cenosphere concentration across the interface, affirming the gradation in the prepared samples. The results show that appropriate compositions of FGSFs can be selected to develop materials with improved mechanical performance. 2014 Society of Plastics Engineers.
Compressive and flexural properties of functionally graded fly ash cenosphere-epoxy resin syntactic foams
(John Wiley and Sons Inc, 2015) Doddamani, M.; Kishore; Shunmugasamy, V.C.; Gupta, N.; Vijayakumar, H.B.
The present study focuses on developing functionally graded syntactic foams (FGSFs) based on a layered co-curing technique. The FGSFs were characterized for compressive and flexural properties and compared with plain syntactic foams. The results showed that the specific compressive modulus was 3-67% higher in FGSFs compared to plain syntactic foams. FGSF exhibited 5-34% and 34-87% higher specific modulus and strength, respectively in flexural mode. The microscopic examinations of comparative responses of the filler and matrix to deformation suggest that the failure is dominated by the matrix. The gradient in the composition of syntactic foams helps in effectively distributing the stress throughout the microstructure and results in improved mechanical performance of syntactic foams. From the microscopy studies, it is evident that, the failure mechanism in the FGSF under flexural loading is governed by a crack that initiated on the tensile side of the specimen and propagated through the thickness to cause complete fracture. The microscopic observations further clearly demonstrate the existence of seamless interfaces between the layers and a clear difference in the cenosphere concentration across the interface, affirming the gradation in the prepared samples. The results show that appropriate compositions of FGSFs can be selected to develop materials with improved mechanical performance. © 2014 Society of Plastics Engineers.
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 schlagz higkeitsdaten in epoxidsystemen mit und ohne silanbeschichtete flugascheteilchen in unterschiedlichen volumenanteilen]
(2004) Kishore; Ravikumar, N.L.; Kulkarni, S.M.
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.
Dry sliding wear of epoxy/cenosphere syntactic foams
(2015) Manakari, V.; Parande, G.; Doddamani, M.; Gaitonde, V.N.; Siddhalingeshwar, I.G.; Kishore; Shunmugasamy, V.C.; Gupta, N.
Abstract Dry sliding wear behavior of epoxy matrix syntactic foams filled with 20, 40 and 60 wt% fly ash cenosphere is reported based on response surface methodology. Empirical models are constructed and validated based on analysis of variance. Results show that syntactic foams have higher wear resistance than the matrix resin. Among the parameters studied, the applied normal load (F) had a prominent effect on wear rate, specific wear rate (ws) and coefficient of friction (?). With increasing F, the wear rate increased, whereas ws and ? decreased. With increase in filler content, the wear rate and ws decreased, while the ? increased. With increase in sliding velocity as well as sliding distance, the wear rate and ws show decreasing trends. Microscopy revealed broken cenospheres forming debris and extensive deformation marks on the wear surface. 2015 Elsevier Ltd.
Dry sliding wear of epoxy/cenosphere syntactic foams
(Elsevier Ltd, 2015) Manakari, V.; Parande, G.; Doddamani, M.; Gaitonde, V.N.; Siddhalingeshwar, I.G.; Kishore; Shunmugasamy, V.C.; Gupta, N.
Abstract Dry sliding wear behavior of epoxy matrix syntactic foams filled with 20, 40 and 60 wt% fly ash cenosphere is reported based on response surface methodology. Empirical models are constructed and validated based on analysis of variance. Results show that syntactic foams have higher wear resistance than the matrix resin. Among the parameters studied, the applied normal load (F) had a prominent effect on wear rate, specific wear rate (ws) and coefficient of friction (?). With increasing F, the wear rate increased, whereas ws and ? decreased. With increase in filler content, the wear rate and ws decreased, while the ? increased. With increase in sliding velocity as well as sliding distance, the wear rate and ws show decreasing trends. Microscopy revealed broken cenospheres forming debris and extensive deformation marks on the wear surface. © 2015 Elsevier Ltd.
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.
2005
Neat epoxy (NE) and epoxy system with different volume fractions of fly ash fillers with their surfaces treated by silane bearing material were made and the responses to exposure by immersion in varying aqueous media, such as plain water (PW), seawater (SW) and seawater containing small amount of dilute hydrochloric acid (SWA) maintained at 80°C, established through weight measurements recorded up to 100 h on the test coupons. Further on, the 100 h exposed samples were subjected to compression tests to evaluate the strength. The results showed that both NE and the silane treated ash bearing composites generally exhibited the highest water absorption in SWA case and the lowest in SW media, with the water absorption level for PW case falling in between. When the ash content in the composite is very large, the water absorption levels tend to be lower for both SW and SWA. The data further showed that unexposed samples recorded less strength compared to the exposed ones. In the case of exposed samples, in all the media employed, as the ash content increases the strength also increases. Further, it was noticed that the samples exposed to SW showed higher strength than the corresponding values noticed with SWA case. Lower strength was found in samples immersed in PW case. Attempts to explain these differing trends are made in this effort by analyzing the features observed on the surface of compression failed samples using fractography technique employing scanning electron microscope (SEM).
(Compression strength of aqueous media exposed epoxy system containing silane surface bearing fly ash particles) Kishore; Ravikumar, N.L.; Kulkarni, S.M.
2004
Sliding wear behaviour of an epoxy system reinforced with particulate fly ash filler
(2009) Barpanda, P.; Kulkarni, S.M.; Kishore
Neat epoxy and epoxy containing different volume fraction of as received fy ash particulate fller bearing composites were cast, sectioned and subjected to pin-on-disk tests for evaluating the wear behaviour. The wear tests were conducted for 1 kilometre distance under 1 kg load for sliding velocity ranging from 1 to 5 m/s. The results showed that both neat epoxy and fy ash bearing composites exhibit differing magnitudes of wear loss, it being highest for unreinforced neat epoxy system. The data trends point to the fact that wears loss decreases with increasing content of fy ash in composites. To explain these differences, the wear surfaces were examined under scanning electron microscope and the features thus observed were correlated with the mechanical data.
Sliding wear behaviour of an epoxy system reinforced with particulate fly ash filler
(Adcotec Ltd. info@sagepub.co.uk, 2009) Barpanda, P.; Kulkarni, S.M.; Kishore
Neat epoxy and epoxy containing different volume fraction of as received fy ash particulate fller bearing composites were cast, sectioned and subjected to pin-on-disk tests for evaluating the wear behaviour. The wear tests were conducted for 1 kilometre distance under 1 kg load for sliding velocity ranging from 1 to 5 m/s. The results showed that both neat epoxy and fy ash bearing composites exhibit differing magnitudes of wear loss, it being highest for unreinforced neat epoxy system. The data trends point to the fact that wears loss decreases with increasing content of fy ash in composites. To explain these differences, the wear surfaces were examined under scanning electron microscope and the features thus observed were correlated with the mechanical data.
The effect of the inclusion of ceramic particles in polythene material on the response to erosion due to impingement by sand particles at three angles is investigated. It is seen that erosion resistance varies with ceramic inclusions. The work also considers the limitations posed by the system in adopting weight change measurements as a measure to follow erosive wear owing to the softer nature of the matrix material. Consequently, the investigation looks at two other experimental parameters that can readily be measured to quantify erosion. Of the two approaches, the advantages of following wear through measuring linear dimension of the resulting crater is stressed in this work. The study also highlights the problems associated in assessing the depth of the crater as a parameter to express the extent of erosion owing to the phenomenon of material flow suggested and schematically illustrated in the work. Corroborative evidence for this flow behaviour through scanning electron microscopic studies is presented. © 2002 Elsevier Science Ltd. All rights reserved.
(Elsevier Ltd, On evaluating erosion by sand particles in polythene system without and with ceramic particles) Kishore; Sridhar, G.B.
2002
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.
2004