Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
11 results
Search Results
Item Development of Sustainable Jute/Epoxy Composite and Assessing the Effect of Rubber Crumb on Low Velocity Impact Response(Taylor and Francis Ltd., 2022) Mahesh, V.; Mahesh, V.; Harursampath, D.; Joladarashi, S.; Kulkarni, S.M.In the current study, the experimental assessment of influence of rubber crumb on the low velocity impact (LVI) behavior of jute epoxy composites are carried out using two types of impactors namely hemispherical and conical. Hand layup technique is used to fabricate the proposed composites. The rubber crumb is incorporated in the epoxy resin with 1.5 wt%, 3 wt%, and 5 wt%. Results revealed that incorporation of 3 wt% of rubber crumb resulted in better LVI response compared to its counterparts. Fractography studies revealed that inclusion of rubber crumb particles enhances the adhesion between resin and fiber, thereby increasing the energy absorption. In addition, they aid in reducing damage area and increasing penetration threshold of proposed composites. The current study’s systematic technique serves as a model for the efficient use and conversion of waste rubber crumb into usable natural fiber reinforced polymer matrix composites for LVI applications. © 2022 Taylor & Francis.Item Effect of Wollastonite Filler on the Experimental and Microstructural Analysis of Epoxy Composite Reinforced with E-glass Fibre(Springer, 2022) Lokesh, K.S.; Pinto, T.; Shrinivasa Mayya, D.; Shanmugam, B.K.; Panduranga, B.P.; Hanumanthappa, H.; Mohanraj, G.T.In the present study, the polymer composite was produced with epoxy, E-glass and wollastonite as the matrix, reinforcement and filler material, respectively. The present study investigates the effect of the filler material on the mechanical performance of developed composite specimens. The reinforcement material selected was woven and chopped-type fibre material. The filler material composition in the woven and chopped-type specimens was individually varied with 0%, 1%, 3%, 5% and 7%. The specimen was subject to mechanical testing, viz., tensile and flexural strength tests. Further, the wear rate of the normal specimen was tested to 5, 10 and 15 min. Additionally, the specimen was subjected to SEM (scanning electron microscope) analysis after attaining fracture for each study. The results showed that the specimen with 1% filler material had better tensile strength. It was also found that the flexural strength was good and was increasing with the filler material. The wear rate was reduced with the increase in filler material composition in the specimen. The results show that the woven fabric specimen shows better mechanical performance than the chopped specimen. © 2022, The Institution of Engineers (India).Item Evaluation of the Wear Behaviour of Thermally Aged E Glass Reinforced Epoxy Composite Filled with Wollastonite Using Taguchi L27 Technique(Springer, 2022) Lokesh, K.S.; Pinto, T.; Mayya, D.S.; Shanmugam, B.K.; Panduranga, B.P.; Hanumanthappa, H.; Mohanraj, G.T.In the present study, the E glass reinforced epoxy composite filled with wollastonite was developed. Taguchi’s L27 technique was selected for developing and analysing the effects of control factors on the wear behaviour of composites. The control factors considered for the present study was filler (%), time (minute) and temperature (°Celsius). The wear experiments were carried out using pin on disc arrangements for different experimental conditions. After the wear test, the microstructural analysis was carried out on the specimens using scanning electron microscope (SEM) analysis. The regression coefficient of 98.8% and probability plot shows that the model was accurate and valid. From the optimization results, it was clear that the 7% filler percentage (high level), 5 min sliding time (low level) and 50 °C temperature (high level) will yield high wear resistance and lower material loss due to the wear of the composites. Further, a confirmation test with the optimized condition was conducted and validated using the SEM image. The results also showed that the Taguchi technique effectively studies the effects of the control factors for obtaining the maximum wear resistance of the composites. © 2022, The Institution of Engineers (India).Item Experimental and numerical investigation on the elastic properties of luffa–cenosphere-reinforced epoxy hybrid composite(John Wiley and Sons Inc, 2024) Gurjar, A.K.; Kulkarni, S.M.; Joladarashi, S.; Doddamani, S.Estimating the elastic characteristics of natural fiber-reinforced polymer composites such as luffa fiber reinforced with epoxy is challenging. The structure of luffa cylindrica is complex, like a three-dimensional natural fibrous mat, netting-like structure. The multiscale modeling of such structures is the challenge to be addressed. The prime objective of this work is to determine the specific elastic properties of luffa–cenosphere-reinforced epoxy (LCE) composite, considering the effect of filler volume fractions. Furthermore, multiscale modeling techniques, such as representative volume elements (RVEs) of finite element techniques with chopped, unidirectional, plain, and twill weaving fiber arrangements, were employed. The longitudinal modulus, transverse modulus, shear modulus, and Poisson's ratio were predicted through these modeling approaches. However, experimental and analytical methodologies, including the rule of mixture and Halpin–Tsai, were considered to validate the finite element analysis results. The elastic characteristics of LCE composite were therefore shown to be enhanced by increasing filler volume fraction. However, the cenosphere's 20% volume fraction has the highest elastic properties as determined by analytical, experimental, and computational models. Analytical and finite element simulation results were compared with the experimental results, and based on the findings, the most suitable (unidirectional, chopped, plain, and twill weaving) RVE was identified for finite element modeling of LCE composite for the evaluation of elastic properties. Results from practical approaches and the RVE twill weaving model showed good agreement, with less than 1% error, compared to the other analytical and finite element methods. Highlights: NFCs are gaining ground in polymer composites. Overcoming challenges in modeling of luffa fiber inside epoxy matrix. The study uses multiscale modeling with diverse fiber arrangements. Experimental and analytical methods used to confirm FEA results. Increased cenosphere volume fraction boosts LCE composite properties. © 2024 Society of Plastics Engineers.Item Jute/basalt fabrics in microcellulosic-filled epoxy composites for lightweight applications(Elsevier Ltd, 2024) Indra Reddy, M.I.; Sethuramalingam, P.; Sahu, R.K.; Kalidindi, K.S.For the production of lightweight, eco-friendly, and incredibly robust products, hybrid bio-epoxy composites stand out as an outstanding material choice in the manufacturing sector. This study focused on creating a composite, where in the epoxy resin infused with microcellulose fillers is reinforced by stacking four layers of basalt-jute-jute-basalt woven mats. The composite was made through the hand lay-up process, followed by the meticulous process of compression molding. The inclusion of microcellulose, sourced from the leaves of the Musa paradisiaca plant (MPPL), was a key component. The extraction of microcellulose from the MPPL involves alkali treatment, acid hydrolysis, bleaching, and slow pyrolysis. This micro cellulose was introduced to the layered composite in varying proportions (ranging from 0 % to 10 %). Subsequently, we carried out comprehensive tests in line with ASTM standards to assess the material's effectiveness with regard to thermo-mechanical properties and water absorption characteristics. The outcomes of these evaluations highlighted that the composite featuring a 5 % Musa paradisiaca plant leaf micro cellulose content within the basalt-jute-jute-basalt layers exhibited notably superior attributes in tensile strength (99.74 MPa), flexural strength (77.87 MPa), impact strength (40.27 kJ/m2), hardness (97 HRRW), and crystallinity index of 6.3 %. Furthermore, our investigation extended to the analysis of fractural morphology to understand the bonding behaviour and fracture patterns within the composite. © 2024 Elsevier B.V.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.Item Effect of alkaline treatment on mechanical properties of natural fiber-reinforced composite(Korean Society of Mechanical Engineers, 2024) Sangamesh, R.; Hiremath, S.; Biradar, S.; Kumar B, S.; Sondar, P.; Vishwanatha, H.M.Natural fiber-reinforced composites are gaining popularity as eco-friendly alternatives to conventional plastics across various industries. This study investigated the fabrication of composites using areca leaves as the reinforcing filler material within an epoxy matrix. The composites were prepared using the hand-layup technique, with different weight fractions of fibers. Before composite fabrication, the areca leaves were treated with NaOH solution. A comprehensive set of tests, including tensile, compression, flexural, impact, and erosion tests, was conducted on these composites to evaluate their mechanical properties. The results showed that untreated composites exhibited superior performance in tensile (39 MPa) and compression tests (59 MPa with 45 % fiber content), while NaOH-treated composites performed better in flexural (64–67 MPa) and impact tests (21 kJ/m2 at higher fiber content). Erosion testing revealed that composites with lower filler concentrations demonstrated improved wear resistance compared to those with higher filler content, with erosion rates significantly influenced by sand concentration and particle size. These findings were supported by fracture surface analysis using scanning electron microscopy (SEM). This study provides valuable insights into the potential of areca leaf-reinforced composites as sustainable materials for various applications. © The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany, part of Springer Nature 2024.Item Epoxy-based composites with size-fractionated waste Areca sheath: an experimental investigation on the macroscopic and vibrational properties(Gruppo Italiano Frattura, 2025) Varghese, L.; Kumar, G.C.The use of Areca sheath in developing a newer composite material is proposed in this article. The Areca sheath particulates are extracted by pulverizing long sheaths into different sizes of particulates and are reinforced into the epoxy to process the composites. The study evaluated these composites' macroscopic and vibrational properties, revealing that those with coarse particulates demonstrated superior tensile and flexural strengths, impact strength, hardness, and natural frequency. Notably, the coarse epoxy composite with a 10% weight fraction of particulates exhibited tensile strength and modulus values of 24 MPa and 1050 MPa, respectively. These findings suggest that incorporating a 10% weight fraction of coarse Areca sheath particulates into epoxy resin significantly enhances the composite's macroscopic and vibrational properties, making it a promising material for various building applications like Partition panels, Ceiling Panels, and similar applications. © 2024, Gruppo Italiano Frattura. All rights reserved.Item Mode-I fracture behaviour of aramid/glass-epoxy interply hybrid composites(SAGE Publications Ltd, 2025) Kanakannavar, S.; Biradar, S.; Hiremath, S.; Rajole, S.; Pitchaimani, J.; Kulkarni, S.M.; Goh, K.-L.This article presents the influence of hybridisation of aramid and glass fibre woven fabric on fracture toughness (KIC) of the composites. Experiments using single-edge-notched-bending (SENB) were conducted to investigate the hybridisation effect on the Mode I fracture toughness specimen of aramid/glass laminates. The results revealed that the aramid epoxy composites yielded the highest KIC, followed by aramid/glass epoxy hybrid composites, and finally, glass epoxy composites, which exhibited the lowest KIC. Fracture micrographs of the hybrid composites showed similar fracture patterns – fibre pullout, fibre rupture and matrix rupture – to those of the aramid and glass epoxy composites. The mechanical properties of the hybrid composites being inferior to those of the aramid epoxy composites suggest that there is no advantage in using glass fibres to partially replace aramid fibres in achieving hybrid composites. © The Author(s) 2025Item Thermal stability and sound absorption in perforated areca sheath-epoxy composite materials(Springer Science and Business Media B.V., 2025) Varghese, L.; Kumar, G.C.The present work emphasizes developing epoxy composites using areca sheath particulates, focusing on improving the thermal and acoustic properties. These composites are developed using conventional methods, and followed by surface modification by different types of perforations using pin perforation techniques. The sound absorption characteristics of these specimens were evaluated using an impedance tube, while thermal stability through thermogravimetric analysis and microstructural properties were analyzed. The results indicate that composite specimens with only half of the area perforated with 1 mm diameter holes demonstrate a superior sound absorption range compared to other specimens. The influence of perforation patterns on specimen surfaces was also studied. Additionally, the thermogravimetric analysis of composites reveals that the developed materials possess significant thermal stability, making them more suitable for thermal and acoustic applications in public buildings and auditoriums than other lightweight composites. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.