Faculty Publications
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Publications by NITK Faculty
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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 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 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 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 Comprehensive Characterization of Novel Jute Fabrics with Musa Paradisiaca Leaf Agro-Waste Based Micro Cellulosic Fillers Reinforced Epoxy Composites For Lightweight Applications(Korean Fiber Society, 2025) Indra Reddy, M.I.; Sethuramalingam, P.; Sahu, R.K.For lightweight, sustainable, high-strength products, hybrid bio-epoxy composites materials were the most excellent choice for the production industry. The investigation proceeds in developing a four-stacked sequence jute-woven mats reinforced with epoxy composite and added with micro-cellulose fillers. The extraction of micro cellulose from Musa paradisiaca plant leaf (MPPL) was carried out through a series of processes, including alkali treatment, acid hydrolysis, bleaching, and slow pyrolysis. The composite was fabricated using the conventional hand lay-up method and compression molding. The microcellulose was added to the stacked composite at varying weight percentages (0, 2.5, 5, 7.5, and 10%). Thermo-mechanical and water intake characterization were investigated using ASTM. The findings revealed that incorporating 5% MPPL cellulose into the jute-stacked layer sequence resulted in improved hardness (95 HRRW), tensile modulus (3407.69 MPa), tensile strength (79.74 MPa), flexural modulus (2195.752 MPa), flexural strength (56.87 MPa), and crystallinity index (72.7%). However, a reduction in impact strength (23.27 kJ/m2) was noted compared to the unfilled composite. The higher thermal degradation (480 °C) behavior of the filler-reinforced composite makes them a suitable material for applications in high-temperature environments. Fractographical morphology was also investigated to reveal the bonding behavior, voids formations, agglomeration of fillers, and fracture behavior. Thus, this distinguishable composite characterization will aid the manufacturing industries in producing high-strength biodegradable materials. © The Author(s), under exclusive licence to the Korean Fiber Society 2025.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.Item Seashell-based filler as sustainable reinforcement: a novel approach to enhance wear performance of bamboo-epoxy composites(Institute of Physics, 2025) Anand, K.J.; Murthy, A.G.S.; Ekbote, T.; Doddamani, S.; Madhusudhana, H.K.; Patil, A.S.Seashell wastes are discarded in landfills, causing environmental problem. This study presents a novel approach to valorize seashell waste by converting them into filler particulates and incorporate it into bamboo–epoxy composites. Composites of varying clamshell filler (0–9 wt%) loading were prepared using compression molding method. The wear behavior of composites was studied under dry sliding conditions on a pin-on-disc tribometer following ASTM G99 standard. Taguchi-ANOVA method was employed for statistical analysis of results and to identify the significant factors affecting wear rate. The results showed that adding seashell particles improved the hardness and wear resistance of the bamboo composites. ANOVA results indicated that load has the maximum effect of 47.4% and speed has the effect of 29.4%. Optimal performance was achieved for 6 wt% filler addition, exhibiting 17% improvement in hardness and wear rate was reduced by 60%. The enhancement in wear resistance of bamboo composite was correlated with an increase in hardness and a decrease in damage to the impact surface, as observed in SEM micrographs. These findings establish clamshell filler as an effective reinforcement for improving wear performance of bamboo composites. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.