Faculty Publications
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Item Optimization of process parameters for ballistic impact response of hybrid sandwich composites(Springer-Verlag Italia s.r.l., 2023) Mohan Kumar, T.S.; Joladarashi, S.; Kulkarni, S.M.; Doddamani, S.The low-cost, eco-friendly ballistic impact resistance materials are gaining more importance in defense applications. The present work investigates the findings of ballistic impact behavior of a Jute-Rubber-Jute-Epoxy (Sand)-Jute-Rubber-Jute (JRJ-ES-JRJ) hybrid sandwich composite for different core thicknesses (10, 15, 20 mm) and different filler composition (0, 20, 40%) subjected to impact at 350 mps using different shaped projectiles like flat (F), conical (C), and hemispherical (H) using a numerical and parametric approach. Hybrid JRJE(%S)JRJ sandwich composites is modeled and simulated using commercially available dynamic explicit software, with the projectile as a rigid body and the target as a deformable material. Simulations are performed as per Taguchi's design of experiments approach for the L27 orthogonal array. The results show that filler composition and core thickness are the most critical factors determining ballistic behavior for the proposed hybrid sandwich composite structure. The Hybrid JRJ-ES-JRJ sandwich composites impacted with a conical-shaped projectile absorb the maximum energy, but the composite impacted with a flat-shaped projectile suffers more severe and immediate damage. © 2022, The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.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 Effects of Addition of Graphite on the Tribological Behaviour of Al7075-SiC Hybrid Composites Using Design of Experiments(Springer Science and Business Media Deutschland GmbH, 2024) Gudipalli, K.R.V.; Chapke, Y.; Hareesha, H.; Doddamani, S.Despite the widespread use of Al7075-SiC composites in various engineering applications, their tribological performance remains a subject of interest due to challenges related to friction and wear. This study addresses the need for improved lubrication in such composites by investigating the potential of Al7075-SiC/Graphite hybrid materials. The incorporation of graphite particles, up to 9% by weight, aims to enhance the self-lubricating properties of these composites. Stir casting is employed to fabricate specimens with varying graphite content (3–9% by weight), followed by comprehensive tribological assessments under dry sliding conditions. Factors including sliding distance, load, and graphite composition are systematically evaluated using Taguchi’s optimization techniques, including design of experiments, ANOVA, and regression analyses. Results reveal that the addition of 9% graphite content notably reduces both the coefficient of friction and wear rate. According to the data, sliding distance significantly impacts wear behaviour, followed by the applied load. In contrast, the composition has a 77% impact on the coefficient of friction than load, while the sliding distance has a relatively small impact. As a result, the Al7075-SiC/Graphite composite material demonstrated its suitability as a self-lubricating substance. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.Item Investigation on Tribological Behavior of Al7075-TiC/Graphene Nano-composite Using Taguchi Method(Springer Science and Business Media Deutschland GmbH, 2024) Lingaraju, S.V.; Hatti, G.; Jadhav, M.R.; Dhuttargaon, M.S.; Doddamani, S.This study addresses the limited understanding of how nano-materials affect the mechanical properties and wear behavior of AMMNCs, focusing on challenges in achieving uniform nano-material distribution and optimizing processing parameters. This study explores the fabrication and tribological performance of Al7075 hybrid metal matrix nano-composites reinforced with TiC and Graphene using ultrasonic stir casting. By varying TiC content (0.5 to 2.5 wt%) and maintaining 0.25-wt% Graphene, the composites were tested under dry sliding conditions. Results indicate that the hybrid nano-composite with 1.5 wt% TiC and 0.25 wt% Graphene exhibits optimal wear resistance and frictional behavior, attributed to improved hardness and reduced surface damage. This results from harder particles intermingling with the softer alloy, which shows increased hardness with reduced delamination, cracks, and fractures of inside surfaces during wear. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.Item Effects of specimen thickness and compositions on the fracture toughness investigations of Al7075-SiC/Al2O3 hybrid composites utilizing Taguchi optimization and FEA analysis(Springer-Verlag Italia s.r.l., 2025) Bharath, P.B.; Shivakumar, S.P.; Rajesh, A.M.; Prabhuswamy, G.S.; Doddamani, S.The primary objective of this study is to investigate the influence of process parameters on the fracture toughness of aluminium–silicon carbide/alumina particulate composites. The composite is fabricated using the stir-casting method, and the study aims to explore the relationship between process parameters and the resulting mechanical properties of the material. The research seeks to answer how varying process parameters such as reinforcement composition, specimen thickness, and crack length-to-width ratio affect the fracture toughness of aluminium-based hybrid composites. A comprehensive experimental approach is employed, utilizing compact tension specimens of varying thicknesses, compositions, and crack length-to-width ratios to assess fracture toughness. Taguchi's optimization techniques, including the design of experiments with an L9 orthogonal array, analysis of variance (ANOVA), and regression analysis, are used to analyze the specified parameters. The three key factors and their respective levels considered in the study are reinforcement composition (3, 6, and 9 wt%), specimen thickness (10, 12, and 15 mm), and crack length-to-width ratio (0.45, 0.47, and 0.50). The experimental results indicate that increasing the composition of reinforcements beyond 6 wt% and certain crack length-to-width ratios decreases the fracture toughness of the hybrid composites. Through Taguchi's analysis, it is revealed that for a crack length-to-width ratio of 0.45, specimens with a thickness of 12 mm and 6 wt% reinforcements exhibit the highest fracture toughness. Further analysis underscores that the crack length-to-width ratio (a/W ratio) significantly affects fracture toughness (94%), followed by reinforcement composition and specimen thickness. The study provides valuable insights into optimizing the fracture toughness of aluminium–silicon carbide/alumina particulate composites. The identified optimized parameters 12 mm specimen thickness, 6 wt% reinforcement, and a 0.45 crack length-to-width ratio lead to enhanced fracture toughness. Additionally, finite element simulations support the experimental findings, with less than a 12% error, confirming the robustness of the optimized conditions. This research contributes to a deeper understanding of the interplay between process parameters and mechanical properties in particulate composite materials. © The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature 2025.