Faculty Publications
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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 Effect of temperature on wear and friction performance of WC-Co and Cr3C2 reinforced with 17-4PH Fe-based composite coatings(Springer Science and Business Media Deutschland GmbH, 2024) Chandramouli, T.V.; Joladarashi, S.; Ramesh, M.R.; Rahman, M.R.Surface protection is crucial in industrial equipment and tools to prevent wear and friction in harsh environments, particularly at high temperatures, where anti-friction coatings are essential for optimal performance. The present research investigates the tribological properties of high-velocity oxy-fuel sprayed coatings of 17-4PH stainless steel reinforced with tungsten carbide and chromium carbide powders. The coatings are deposited onto a maraging steel substrate. A dry sliding wear test was performed using an alumina ball as a counter body under various test temperatures (25 °C, 300 °C, and 600 °C) and loads (10 N and 30 N). The coating is characterized by employing SEM, XRD, micro-hardness tester, particle analyzer, and bond strength tester, and the mechanism of wear reduction was discussed. The post-wear analysis was carried out on the wear track using SEM/EDS and 3D non-contact optical profilometers. The micro-hardness and bond strength of both (17-4PH-30%WC-Co and 17-4PH-30%Cr3C2) coatings are compared. The test results revealed that at all temperatures and loads, 17-4PH-30%WC-Co coating shows better wear resistance and lower friction coefficient than the 17-4PH-30%Cr3C2 coating. The significant influence of the tribo-oxide layer at high temperatures, which contributed to decreasing wear rate and coefficient of friction, was premeditated. © 2023, International Institute of Welding.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 Microstructure, Mechanical Properties, and Tribological Properties of Fe-Based Composite Coatings Reinforced with WC-Co and Cr3C2(Springer, 2025) Chandramouli, T.V.; Joladarashi, S.; Ramesh, M.R.; Rahman, M.R.Fe-based (stainless steel 316L) coatings are widely employed in the aerospace, chemical processing, petrochemical, and marine industries owing to their low and stable price, excellent corrosion resistance, and durability. However, at elevated temperatures, their performance is limited due to wear. Thus, the current investigation incorporates tungsten carbide (WC-Co) and chromium carbide (Cr3C2) into the Fe-based coating to enhance its wear resistance at high temperatures. SS316L reinforced by 30% of WC-Co and Cr3C2 by mechanical mixture, then sprayed using high-velocity oxy fuel spraying method. Coating characteristics, such as microstructures and phase analysis, were measured using FESEM/EDS and XRD. Coating density, microhardness, and bond strength were examined by water immersion, Vickers indentation, and ASTM C-633 methods, respectively. A ball-on-disk tribometer was employed to conduct wear examination at various temperatures (25, 300, and 600 °C) and loads (10 and 30 N) against the alumina counter body. The wear rate and friction coefficient of SS316L-30%WC-Co decrease from 25 to 600 °C, while the wear rate of SS316L-30%Cr3C2 increases with temperature up to 300 °C and then decreases at 600 °C. The oxide phase adheres strongly to underlying surfaces forming a protective layer (Cr2O3, NiWO4, Fe2O3, and NiMO4), changing the mode of wear mechanism. At higher temperatures and loads, the coating exhibited oxidation modified adhesive wear, and coatings provide excellent wear resistance along with reduction in friction. This research provides a novel approach for future standardization and evaluation of coatings on metal alloys for industrial applications. © ASM International 2024.Item Surface enhancement of SS304 for high-temperature wear resistance using laser cladded Mo-alloyed stellite 6 coatings(Elsevier B.V., 2025) Aprameya, C.R.; Joladarashi, S.; Ramesh, M.R.Severe wear often limits the high-temperature durability of SS304 components, necessitating the development of surface-engineered solutions. In this investigation, Mo-reinforced Stellite 6 claddings were developed using Laser Directed Energy Deposition (L-DED) to provide enhanced surface protection. Claddings with (3, 6, and 9 wt%) Mo reinforcement enhanced hardness by 2.9, 3.1, and 3.3 times, respectively, compared to the SS304 substrate. This improvement is attributed to Mo-induced solid solution strengthening and the formation of hard intermetallic phases. Dry sliding wear tests were conducted at RT and 600 °C under (10 and 20 N) loads. Wear characterisation of the clads was performed using OM, XRD, FE-SEM, EDX, and Raman spectroscopy. At RT, claddings primarily exhibited abrasive wear with minor plastic deformation. However, at 600 °C, the wear mechanism evolved into a combination of severe adhesive, oxidative, abrasive, and plastic deformation modes, with oxidative wear governing the tribological behavior. Stellite 6 with 9 wt% Mo clads exhibited better tribological performance than the other two variants, owing to the development of oxide glaze layers of Cr2O3, NiO, CoO2, and Co3O4. Enhanced performance of the claddings is attributed to solid solution strengthening, Cr-rich carbide formation, increased dislocation density, and the L-DED technology enabling refined microstructure and strong metallurgical bonding. These findings highlight the potential for further advancements in Mo-reinforced Stellite 6 L-DED claddings for high-temperature wear applications. © 2025 Elsevier B.V.