Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
7 results
Search Results
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 Statistical analysis of flexural modulus of cenospheres-reinforced, recycled poly(ethylene terephthalate) using Taguchi method(SAGE Publications Ltd, 2014) Prabhu, B.K.; Dudse, S.; Kulkarni, S.M.Statistical methods are playing an important role in the design and analysis of engineering experiments. One such method called Taguchi method is found to provide sufficient information to optimize a process with the use of minimum number of experiments. This article presents systematic application of Taguchi method for optimizing the process parameters of compression moulding process. The response under consideration is flexural modulus. The study includes the use of recycled polyethylene terephthalate reinforced with fly ash cenospheres. The use of these recycled materials is promising to reduce the cost of the engineering parts and help nature by increasing waste utilization. A model for flexural modulus is designed and verified through experiments. The outcome from analysis of variance brings out the facts that moulding pressure, moulding temperature and weight fraction of cenospheres are the three most significant parameters of flexural modulus, contributing 59.44, 21.45 and 7.75%, respectively. The optimum set values for these parameters are found to be 5 MPa, 50°C and 15%. The proposed quadratic model for flexural modulus proves to be well in agreement with the experimental results. © The Author(s) 2013.Item Influence of weave pattern and composite thickness on mechanical properties of bamboo/epoxy composites(Institute of Physics Publishing helen.craven@iop.org, 2019) Kanaginahal, G.M.; Hebbar, H.S.; Kulkarni, S.M.The results of an attempt made for studying the influence of weave pattern and composite thickness of plain and twill weave bamboo fabric reinforced epoxy/phenalkamine composites on static mechanical properties are reported in this paper. Plain weave and Twill weave bamboo fabric of 125 gsm were used as reinforcements with medium viscous epoxy B-11 resin and highly viscous AI 1041 phenalkamine bio-based hardener. Thickness of composite achieved were 3.1, 4.3 and 5.4 mm with fiber weight fraction at 18% by hand layup method. The aim was to study the influence of weave pattern and thickness of composite on the tensile, flexural and impact properties. Fourier Transform Infra-Red results showed the presence of cellulose, polysaccharides, cardanol groups and hydrogen bonding of reinforcement and matrix. X-Ray Diffraction peaks displayed higher intensities for twill weave fabric. Tensile studies of fabrics showed 7% higher strength for twill weave compared to that of plain weave fabric in warp direction. Twill weave composites with 5.4 mm thickness showed an increase of 12% in tensile strength and 8% increase in stiffness compared to plain weave composite of same thickness. Twill weave composite with 5.4 mm thickness showed an increase of 22% in flexural strength and 28% in stiffness compared to plain weave composite of same thickness. Izod impact results displayed an increase of 16% in absorbed energy for 5.4 mm thickness twill weave composite when compared with plain weave composite of same thickness. Fractography of fractured specimens of tensile test displayed fiber pullouts for plain weave composites and fiber breakage for twill weave composites. Twill weave composites have shown better wettability than that of plain weave composites. © 2019 IOP Publishing Ltd.Item Comparative study of damage behavior of synthetic and natural ber-reinforced brittle composite and natural ber-reinforced exible composite subjected to low-velocity impact(Sharif University of Technology, 2020) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.In the present study, a comparative study of the damage behavior of Glass-Epoxy (GE), Jute-Epoxy (JE) laminates with [0=90]s orientation, and Jute-Rubber-Jute (JRJ) sandwich is carried out by ABAQUS/CAE nite element software. The GE, JE laminate, and JRJ sandwich with a thickness rate of 2 mm are impacted by a hemispherical-shaped impactor at a velocity of 2.5 m/s. The mechanisms by which the brittle laminate gets damaged are analyzed in accordance with Hashin's 2D failure criterion, and exible composites are analyzed by the ductile damage mechanism. The absorbed energy and the incipient point of each laminate were compared. According to the results, there was no evidence of delamination in JRJ as opposed to GE and JE. The compliant nature of a rubber plays a role in absorbing more energy, which is slightly higher than the energy absorbed in GE. Moreover, it was observed that there was no incipient point in JRJ sandwich, meaning that there was no cracking of matrix since the rubber was elastic material. Thus, the JRJ material can be a better substitute for GE laminate in low-velocity applications. The procedure proposed for the analysis in the present study can serve as a benchmark method for modeling the impact behavior of composite structures in further investigations. © 2020 Sharif University of Technology. All rights reserved.Item Evaluation of tensile strength and slurry erosive behaviour of jute reinforced natural rubber based flexible composite(International Information and Engineering Technology Association info@iieta.org, 2020) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.Polymer based natural fiber reinforced composites are finding their applications in almost all fields of engineering. Flexible composites are different class of composite materials finding their usage in secondary structural application such as sacrificial structures like claddings. Mechanical and tribological characterization of the newly developed composites becomes important prior to using them in any engineering application. The present study concentrates on evaluating the tensile and slurry erosive behaviour of flexible composite manufactured by reinforcing naturally available jute fiber in the form of woven fabric in the naturally available sun dried rubber sheets (NR) using compression moulding technique. ASTM D412 standard is used to evaluate the tensile properties of the proposed flexible composite and the NR sheets. The slurry erosive behaviour is assessed using Ducom slurry erosion testing machine. The results reveal that reinforcing jute with natural rubber enhances the tensile strength compared to natural rubber sheet and the wear of the proposed flexible composite is minimal due to inclusion of natural rubber which is elastic in nature. © 2020 Lavoisier. All rights reserved.Item Development and mechanical characterization of novel polymer-based flexible composite and optimization of stacking sequences using VIKOR and PSI techniques(SAGE Publications Ltd, 2021) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.The development of natural fiber-reinforced polymer composites is becoming prominent in numerous engineering applications over the synthetic fiber-reinforced composites mainly because of their environment-friendly characteristics. This article deals with comparative study on selection of optimal stacking sequence (jute/rubber/jute (JRJ), jute/rubber/rubber/jute, and jute/rubber/jute/rubber/jute) of the jute/natural rubber-based completely biodegradable flexible composite using multi-attribute decision making (MADM) approaches namely hybrid entropy-VIse Kriterijumska Optimizacija kompromisno Resenja (VIKOR) and preference selection index (PSI) methods. Tensile strength, tear strength, specific impact strength, and specific wear rate are used as attributes for MADM methods. The results show good agreement between hybrid entropy-VIKOR and PSI methods used for stacking sequence selection. Scanning electron microscope analysis is carried out to study the failure mechanisms of the proposed flexible composite. The findings of the present study led to the choice of JRJ as the preferred stacking sequence among all the three stacking sequences considered as it exhibited the best overall properties compared to other two configurations of the flexible composite. © The Author(s) 2019.Item Influence of sea sand reinforcement on the static and dynamic properties of functionally graded epoxy composites(Springer Science and Business Media Deutschland GmbH, 2024) Mohan Kumar, T.S.M.; Joladarashi, S.; Kulkarni, S.M.; Doddamani, S.This study aims to study the static and dynamic properties of the functionally graded epoxy composites with sea sand particles as reinforcement. In this study, functionally graded polymer composites (FGPC) were fabricated by dispersing sea sand throughout the epoxy, exhibiting a spatially varying composition profile within the material. Physio-mechanical properties and high strain rate compression responses were determined for the prepared FGPC by varying the composition of sea sand [0%, 10%, 20%, and 30% (by weight)]. The gradience analysis was performed using the burn-out test and weight method, and the results significantly matched, as well as the variation in gradation could be identified. The density and void content are increased with increased sea sand composition. Tensile and specific strength for neat epoxy shows a 2.41 times increase compared to 30% sea sand-filled epoxy. When loaded from the composite side of FGPC, flexural strength increased by 27.93%, hardness increased by 12.47%, and impact strength increased by 2.35 times for 30% sea sand-filled epoxy compared to neat epoxy. Under dynamic compression loading, FGPC was subjected to split-Hopkinson pressure bar experiments for neat and filled epoxy. These samples were deformed at strain rates in the 103 s?1 while subjected to pressures of 2, 3, and 4 bar. Stress–strain curves and the strain rate were computed using the raw data. High strain rates improve compressive strength, which increases exponentially as the strain rates increase. Scanning electron microscopy micrographs of the fractured specimen are employed to analyze the fracture characteristics. Graphical Abstract: (Figure presented.) © Iran Polymer and Petrochemical Institute 2024.