Faculty Publications
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Item Influence of laminate thickness and impactor shape on low velocity impact response of jute-epoxy composite: FE study(Elsevier Ltd, 2019) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.This paper aims at numerical and parametric investigation on the outcome of low velocity impact (LVI) response of jute/epoxy (JE) composite of varied thickness subjected to impact at varied velocity of impact within LVI regime using different shaped impactors. The JE composite laminate with varying thickness of 6 mm to 10 mm is subjected to LVI at impact velocity varying from 2 m per second (mps) to 8 mps using impactors of hemispherical (HS), flat (F) and conical (C) shapes. Modelling and simulation of the proposed JE composite laminate is achieved using explicit software available commercially with target as deformable material and the impactor as a rigid body. Simulations are carried out for available possible combination of thickness, impact velocity and impactor shapes. Results reveal that thickness is one of the crucial factors that decide the LVI response of the proposed composite laminate. Laminate impacted with conical shaped impactor results in maximum absorption of energy and the laminate impacted with flat shaped impactor results in bigger and immediate damage. © 2019 Elsevier Ltd.Item An experimental investigation on low-velocity impact response of novel jute/rubber flexible bio-composite(Elsevier Ltd, 2019) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.This paper presents an experimental investigation on low velocity impact (LVI) behaviour of flexible biocomposite laminates with different stacking sequence namely jute/rubber/jute (JRJ), jute/rubber/rubber/jute (JRRJ), jute/rubber/jute/rubber/jute (JRJRJ) and subjected to different impact energy levels using a conical shaped impactor. The performances of the proposed flexible composites are evaluated based on their energy absorption, peak force, coefficient of restitution (CoR), energy loss percentage (ELP) and failure behavior. Results indicated that JRJ provides better energy absorption and JRJRJ provides better damage resistance when subjected to LVI. Microscopic analysis revealed that the flexible composites fail mainly due to the tearing mechanism of the matrix as opposed to cracking in case of conventional stiff composites. It was also found that flexible composites are free from delamination. Compared to conventional stiff composites, there is no catastrophic failure observed in the proposed flexible composite. The overall performance evaluation of these proposed flexible composites indicates that these flexible composites can be potential sacrificial materials such as claddings used to protect primary structural components subjected to LVI. The systematic methodology employed in the present study serves as a benchmark for the effective utilization and selection of flexible composites for LVI applications. © 2019 Elsevier LtdItem A Novel Flexible Green Composite with Sisal and Natural Rubber: Investigation under Low-Velocity Impact(Taylor and Francis Ltd., 2022) Rajkumar, D.; Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.The present work concentrates on assessing the low-velocity impact (LVI) response of sisal-natural rubber (NR)-based flexible green composite in two different stacking sequences, namely, sisal/rubber/sisal (SRS) and sisal/rubber/sisal/rubber/sisal (SRSRS). The influence of the impactor shape on LVI response of the proposed composite was assessed using hemispherical and conical-shaped impactors. Results showed that the proposed composites exhibit better energy absorption and resistance to damage due to inclusion of compliant matrix. The study of damage mechanism of the proposed composites showed that the inclusion of NR as a matrix material in the proposed composites helps to avoid catastrophic failure since rubber undergoes failure by matrix tearing as opposed to matrix cracking as in the case of stiff composites. The proposed composites eliminate two of the major damage mechanisms, namely, matrix cracking and delamination, due to usage of compliant matrix material. The results obtained suggest that the proposed flexible composites can serve as excellent sacrificial structures. The outcome of the present study serves as a benchmark for interested designers/engineers to explore the usage of natural material candidates for developing sustainable impact-resistant composites. © 2022 Taylor & Francis.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 High-Velocity Impact Behavior of Sandwich Composite with Compliant Skin and Sea Sand Strengthened Functionally Graded Core: Experimental and FE Approach(Korean Fiber Society, 2025) Mohan Kumar, T.S.M.; Joladarashi, S.; Kulkarni, S.M.; M, V.The present study investigates optimizing the impact resistance of novel functionally graded sandwich composites using numerical and experimental approaches. The high-velocity impact (HVI) behavior of functionally graded core sandwich composite (FGCSC) with bio-based jute/natural rubber skin and epoxy/sea sand (varying sea sand percentage 0, 10, 20 and 30%, and varying core thickness 10, 20, and 30 mm) functionally graded core. High-velocity impact (HVI) tests are performed using gas gun equipment at an impact velocity ranging from 200, 275, and 350 m/s. The weight residual and burnout method were used to test the gradience of core; both techniques showing significant correlation, and the variance in gradation could be observed. For FE analysis, the FGCSC are represented as deformable bodies, and the bullet is defined as a rigid body using commercially available dynamic explicit software. The HVI test results show that the proposed FGCSC has higher energy absorption capabilities, with core thicknesses of 30 mm and sea sand composition of 30%, resulting in a 1.80% improvement in energy absorption. A finite element study is also carried out to correlate the results, and the obtained results are in better agreement with the experimental findings. The damage analysis indicates that the developed FGCSC with flexible face sheets results in better damage mitigation. The findings suggest that FGCSCs are highly effective for bullet-proofing applications, including personal protective gear and structural components in defense. Further study and optimization could enhance the applicability of these sandwich composites in various protective and structural uses. © The Author(s), under exclusive licence to the Korean Fiber Society 2025.