Faculty Publications
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Item Experimental investigation on slurry erosive behaviour of biodegradable flexible composite and optimization of parameters using Taguchi's approach(Lavoisier, 2018) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.In the present study, the emphasis is on analysing the slurry erosive behaviour of novel green flexible composite made from jute fiber and natural rubber of ribbed smoke sheet (RSS) grade. The bonding gum made of natural rubber is used to bind the fiber and RSS rubber. Three different stacking sequences namely jute-rubber-jute (JRJ), jute-rubber-rubberjute (JRRJ) and jute-rubber-jute-rubber-jute (JRJRJ) are considered. Erosive studies are carried out on the prepared composites under three different rotation speeds (500, 1000 and 1500 rpm) and three different sand concentration (50, 75 and 100 gms) with silica sand as the abrasive medium dispersed in tap water. Design of experiments (DOE) is carried out using Taguchi's L9 orthogonal array on slurry erosion test to find out the effect of the stacking sequence, rotation speed and sand concentration on the weight loss of the composite. Through ANOVA, it was concluded that sand concentration is the main factor affecting the weight loss of composite. Regression model is developed and it was found that the developed model is adequate and feasible to predict the weight loss due to slurry erosion within the range of experimental conditions. © 2018 Lavoisier. All rights reserved.Item Physio-mechanical and wear properties of novel jute reinforced natural rubber based flexible composite(Institute of Physics Publishing helen.craven@iop.org, 2019) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.This paper deals with the design, fabrication, physio-mechanical and wear characterization of the composites prepared from naturally available jute fiber and rubber matrix materials. Jute and natural rubber are cost effective, abundant and environmental friendly materials which can be used as fiber and matrix respectively. The flexible composite with different stacking sequence are manufactured using compression moulding machine and void percentage, water absorption percentage, tensile properties, tear strength, impact strength and shore hardness of the prepared composites are found along with the wear. The void content and water absorption are found to increase with increased number of plies in the composite with fibers contributing more compared to rubber. Tensile, tear, specific wear rate and hardness are found to better with a composite having minimum number of plies, which is JRJ. Charpy impact test revealed that the variation in specific impact strength of the three configuration of composites are negligible and no failure of composites were absorbed owing to their flexibility indicating all the three composites have additional capability to absorb much higher energy and suitable as sacrificial components for structural applications subjected to low velocity impact. The fractography analysis of tensile and tear test shows that the flexible composites are free from matrix cracking, but matrix tearing plays a vital role in failure. The mechanism of wear involved in the proposed composites when different constituents of the composite are exposed to abrasive medium is studied through surface morphology. © 2019 IOP Publishing Ltd.Item Experimental study on Abrasive wear behaviour of flexible green composite intended to be used as Protective Cladding for Structures(ModTech Publishing House office@hotelfloramamaia.ro, 2019) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.In the present study, the influence of material and process parameters on the two body abrasive wear behavior of Jute-Rubber flexible composite is investigated using Taguchi’s design of experiments (DOE). Three different stacking sequences of composite namely jute-rubber-jute (JRJ), jute-rubber-rubber-jute (JRRJ) and jute-rubber-jute-rubber-jute (JRJRJ) are considered and their wear behavior is evaluated using two body abrasion test with multi-pass condition for abrading distances of 0.4 m to 1.2 m in increments of 0.4 m and varied load of 9.81 N, 12.26 N and 14.71 N. Abrasive volume loss and specific wear rate as function of abrading distance are determined. The results from Taguchi’s design of experiments show that for two body dry sliding wear situation, an abrading distance significantly affects the specific wear rate compared to load and composite configuration. However, volume loss is more and appreciable when jute fabric is exposed to abrasive medium rather than when the rubber is exposed. Surface morphology study is carried out using a scanning electron microscope to get an insight of wear mechanism of constituents of the flexible composite. Stretching of asperities results in wear of the rubber, whereas fiber breakage causes wear of the jute. Rubber being the dominating constituent of flexible composite results in providing better wear resistant properties and thus can act as a potential candidate for sacrificial structures to protect primary structures subjected to wear. © International Journal of Modern Manufacturing Technologies.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 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 Tribo-mechanical characterization and optimization of green flexible composites(ICE Publishing, 2020) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.The use of natural fibers as a substitute for synthetic fibers as reinforcement in polymer-based composites is finding prominence nowadays. The present paper deals with the comparative study of biodegradable flexible composites fabricated using jute fabric and rubber with different configurations-namely, jute/rubber/jute (JRJ), jute/rubber/rubber/jute (JRRJ) and jute/rubber/jute/rubber/jute (JRJRJ)-using their tribo-mechanical properties as the attributes and making use of a multi-attribute decision making (MADM) approach-namely, technique for order of preference by similarity to ideal solution (Topsis). The tensile strength, tear strength, interlaminar shear strength and specific wear rate of the proposed composites are chosen as the attributes for comparison using Topsis. The results show that JRJRJ is the best configuration among the considered configurations of flexible composites, providing the overall best tribo-mechanical properties, and the fractography study shows that the proposed flexible composites undergo failure mainly due to matrix tearing in the case of tensile and tear tests as opposed to matrix cracking in the case of stiff composites. Also, the wear study reveals that rubber exhibits better resistance to wear. This study shows the efficient application of the statistically based MADM tool Topsis for material selection. © 2020 ICE Publishing: All rights reserved.Item Influence of thickness and projectile shape on penetration resistance of the compliant composite(China Ordnance Industry Corporation, 2021) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.The present study deals with development of conceptual proof for jute rubber based flexible composite block to completely arrest the projectile impacting the target at high velocity impact of 400 m/s through numerical simulation approach using finite element (FE) method. The proposed flexible composite blocks of repeating jute/rubber/jute (JRJ) units are modelled with varying thickness from 30 mm to 120 mm in increments of 30 mm and impacted by flat (F), ogival (O) and hemispherical (HS) shaped projectiles. All the considered projectiles are impacted with proposed flexible composite blocks of different thicknesses and the penetration behaviour of the projectile in each case is studied. The penetration depth of the projectile in case of partially penetrated cases are considered and the effect of thickness and projectile shape on percentage of penetration depth is statistically analyzed using Taguchi's design of experiments (DOE). Results reveal that the though proposed flexible composite block with thickness of 90 mm is just sufficient to arrest the complete penetration of the projectile, considering the safety issues, it is recommended to use the flexible composite with thickness of 120 mm. The nature of damage caused by the projectile in the flexible composite is also studied. Statistical studies show that thickness of the block plays a prominent role in determining the damage resistance of the flexible composite. © 2020 The AuthorsItem Damage mechanics and energy absorption capabilities of natural fiber reinforced elastomeric based bio composite for sacrificial structural applications(China Ordnance Industry Corporation, 2021) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.The present study deals with the experimental, finite element (FE) and analytical assessment of low ballistic impact response of proposed flexible ‘green’ composite make use of naturally available jute and rubber as the constituents of the composite with stacking sequences namely jute/rubber/jute (JRJ), jute/rubber/rubber/jute (JRRJ) and jute/rubber/jute/rubber/jute (JRJRJ). Ballistic impact tests were carried out by firing a conical projectile using a gas gun apparatus at lower range of ballistic impact regime. The ballistic impact response of the proposed flexible composites are assesses based on energy absorption and damage mechanism. Results revealed that inclusion of natural rubber aids in better energy absorption and mitigating the failure of the proposed composite. Among the three different stacking sequences of flexible composites considered, JRJRJ provides better ballistic performance compared to its counterparts. The damage study reveals that the main mechanism of failure involved in flexible composites is matrix tearing as opposed to matrix cracking in stiff composites indicating that the proposed flexible composites are free from catastrophic failure. Results obtained from experimental, FE and analytical approach pertaining to energy absorption and damage mechanism agree well with each other. The proposed flexible composites due to their exhibited energy absorption capabilities and damage mechanism are best suited as claddings for structural application subjected to impact with an aim of protecting the main structural component from being failed catastrophically. © 2020 The AuthorsItem 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 Three body abrasive wear assessment of novel jute/natural rubber flexible green composite(SAGE Publications Ltd, 2021) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.Determining the resistance to abrasion of the flexible cladding for armours and automobile structural components with the aid of lab scale tests has become increasingly important. In the present study, three body wear behaviour of flexible green composites comprising of jute in woven fabric form with interleaved natural rubber sheets bonded through rubberized B stage cured Pre pegs have been studied. Flexible composites are fabricated in three different configurations having different layers of jute and rubber. The present study makes use of silica sand as the abrasive medium. The specific wear rate along with loss in mass and volume of the composite due to wear is determined and it was found that specific wear rate is dependant of the sliding distance. Comparing the specific wear rate of all the three stacking sequences, it was found that JRJ stacking sequence provides better wear resistance. Compliant and tough nature of the rubber makes it hard to wear it out through tearing action and also the wear resistance of flexible composites is enhanced with inclusion of rubber. Mechanism of wear in each of the constituent used is studied. The present study serves as a benchmark work for the future research in this area. © The Author(s) 2021.