Browsing by Author "Rajole, S."

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An Optimization Study on Material Selection for FRPCs in Multi Layered Armour System through Hybrid MCDM Approach and Numerical Simulation
(Syscom 18 SRL, 2022) Gowda, D.; Bhat, R.; Rajole, S.
Fiber reinforced polymer composites (FRPCs) are considered as core structure in Multi layered armour systems (MAS) to take advantage of maximum energy absorption, mobility and cost criteria design. In this article, based on the problem defining attribute’s optimal material selection in FRPCs determined by Multiple criteria decisions making (MCDM) approach for considered alternative materials from polymer resin, synthetic and natural fiber. Attribute’s weightage and alternatives priority rank were determined through Fussy-Analytical hierarchy process (F-AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. Obtained rank was compared with Preference selection index (PSI) an another MCDM method, for better computational conformity. Selected materials from MCDM approach, simulated for energy absorption ability and damage after impact were studied by considering Cowper-Symonds constitutive materials model using 3D macro shell analysis. Various impact velocities were considered from 3 to 50 m/s for rigid steel impactor directed towards the deformable plate. Parameter like Residual kinetic energy, Residual velocity, Energy absorption ratio after impact were studied numerically. Simulation results in terms of specific energy absorption were compared with the rank obtained in MCDM approach. Among the polymers considered epoxy, polyurethane and polyester found better choice. In fibers hemp and basalt found better materials choice for heterogenous FRPCs design in ballistic armour. © 2022 Syscom 18 SRL. All rights reserved.
Comparative study on filament wounded and laminated GFRP composites for tensile characterization
(2019) Biradar, S.; Joladarashi, S.; Rajole, S.; Hiremath, S.; Kulkarni, S.M.
The demand of composite materials has increased tremendously in various industries such as processing industries in making tanks used to process chemicals, in commercial and domestic application such as to LPG cylinders, in automobile industries like in case of car bodies, fuel tanks, aerospace industries, where fuselage wings, landing gears, doors and many other parts of aircraft. The current demand for composites is mainly due to high strength to weight ratio. Hence, we need to understand criticality in the design of composite products. In this paper primarily focused on GFRP for pressure vessels. Hence in this work an initial study was done to compare tensile properties of filament wounded GFRP test coupons with laminated GFRP test coupons which are cut as per ASTM D3039, both these types of samples are fabricated by using glass fiber direct rovings of 2400TEX. Tensile testing samples are prepared by directly cutting test coupons from fabricated vessel and whereas in case of laminated GFRP specimen are cut using hand cutting tool. The obtained results are further compared with analytical results. From comparative study, it is found that there exists considerable difference between experimental and theoretical results for tensile strength and tensile modulus in case of specimens prepared from GFRP pressure vessel. The variation in results is mainly due to presence of void content, poor interfacial bonding between fiber and matrix, fiber fragmentation, improper spacing between fibers, the presence of all these possible defects are justified by fractography study of failed samples in a scanning electron microscope. Hence from fractography study it is clearly justified that why there is least percentage error in tensile properties of laminated composites. � 2018 Author(s).
Comparative study on filament wounded and laminated GFRP composites for tensile characterization
(American Institute of Physics Inc. subs@aip.org, 2019) Biradar, S.; Joladarashi, S.; Rajole, S.; Hiremath, S.; Kulkarni, S.M.
The demand of composite materials has increased tremendously in various industries such as processing industries in making tanks used to process chemicals, in commercial and domestic application such as to LPG cylinders, in automobile industries like in case of car bodies, fuel tanks, aerospace industries, where fuselage wings, landing gears, doors and many other parts of aircraft. The current demand for composites is mainly due to high strength to weight ratio. Hence, we need to understand criticality in the design of composite products. In this paper primarily focused on GFRP for pressure vessels. Hence in this work an initial study was done to compare tensile properties of filament wounded GFRP test coupons with laminated GFRP test coupons which are cut as per ASTM D3039, both these types of samples are fabricated by using glass fiber direct rovings of 2400TEX. Tensile testing samples are prepared by directly cutting test coupons from fabricated vessel and whereas in case of laminated GFRP specimen are cut using hand cutting tool. The obtained results are further compared with analytical results. From comparative study, it is found that there exists considerable difference between experimental and theoretical results for tensile strength and tensile modulus in case of specimens prepared from GFRP pressure vessel. The variation in results is mainly due to presence of void content, poor interfacial bonding between fiber and matrix, fiber fragmentation, improper spacing between fibers, the presence of all these possible defects are justified by fractography study of failed samples in a scanning electron microscope. Hence from fractography study it is clearly justified that why there is least percentage error in tensile properties of laminated composites. Â© 2018 Author(s).
Effect of Mechanical properties on Multi Axially Forged LM4 Aluminium Alloy
(Elsevier Ltd, 2020) Sajjan, S.S.; Kulkarni, M.V.; Ramesh, S.; Sharath, P.C.; Kumar, V.; Rajole, S.
Commercially available LM4 Aluminum alloy was subjected through Severe Plastic Deformation (SPD) method by Multi-Axial Forging Process (MAF) in ambient temperature. In this process, the material was processed successfully up to 5 Passes and mechanical properties such as tensile strength, compression strength and hardness of the as received and processed samples at ambient temperature were evaluated. The MAF processed sample result showed that the ultimate strength, percentage elongation and compression strength improved by 55 MPa, 3.75% and 162 MPa respectively as compared with the unprocessed sample. Hardness also increased with the increase in the number of passes. In the case of microstructure, grain size reduced from 110 Î¼m to 8 Î¼m after subjecting the sample to MAF. Fractography explains the nature of the fracture from received to processed samples by decreasing the size of the dimple and the type of fracture observed was ductile in nature. Improvement in strength and hardness of processed samples was observed due to the grain refinement and high amount of density dislocation in the material during MAF. Â© 2018 Elsevier Ltd.
Effect of Surathkal Beach Sand on Mechanical Properties of Polymer Composites
(Springer, 2025) Bajpai, N.K.; Bheemanalli, A.; Rajole, S.; Sondar, P.; Ravishankar, K.S.
Although beach sand is available in abundance, its usage in the structural applications has been limited. Prior studies betray that the sand taken in a nanoparticle size for the preparation of polymer nanocomposites yields in improved mechanical and physical polymer properties, also addition of nanophase structure to the polymer has been found to be increasing toughness and cyclic fatigue resistance of the epoxy polymer. The present work uses beach sand as the filler for the reinforced epoxy matrix. Sand-epoxy composites, with different particle sizes (150, 300, 420 μm) and varying filler percentages (5, 10 and 15%) were investigated for mechanical properties. Beach sand nano-particles were considered as high-potential filler materials in the present study owing to their molecular size in a reinforcement and polymer nanocomposites made out of them offer the possibility to develop novel materials with unique properties. As a result, the mixture of 10% filler sand with the particle size of 150 μm showed highest tensile and compressive strength and addition of sand particles beyond 10% led to creation of voids, thereby resulting in decreased strength. It is also noticed that, uniform distribution of sand particles within the matrix and interfacial bonding was the main contributing factors for the increased mechanical properties. The FE analysis of sand epoxy composites was also carried out using ABAQUS finite element analysis tool for flexural failure analysis. Simulations were recorded at various instances till failure. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
Fault Detection and Health Condition Analysis of Single Stage Gear Box System
(Springer Science and Business Media Deutschland GmbH info@springer-sbm.com, 2021) Mohiuddin, B.; Kivade, S.B.; Rajole, S.
Every machine with the relative motion of parts produces sound and vibration. All the gear boxes usually generate vibrations and respective vibration signatures may be taken as referable characteristics if the condition of the gear is good. During working condition, whenever fault occurs, it may result in serious damage of the gear box. The change in the gear pair meshing could result in changes in vibration signals. The accelerometer mounting on the gear box system is the accurate task for assessment of pair of gear. So the technique of monitoring the condition is very essential to prevent and diagnose the vibration of gear box. Nowadays damage identification and condition monitoring of gear boxes in the industrial machinery have received more attention from the researchers. To analyze the various fault and problems related with gear box failure in a working environment efficiently and accurately, few technologies like material technology, information technology, and processing of signals, etc. bring latest solutions. For the assessment of industrial gear boxes, many investigations are carried out for monitoring the condition of machinery. Signal processing and vibration analysis techniques are well known and much suitable for industrial practices. Since, the signals of vibrations from the gear box are transient and non-stationary in nature. Every technique has some disadvantages and may not be used in all condition, i.e., few failure detection is not possible by simple vibration method. At an early stage, simple analysis by spectral is not very successful to find the injury of gear. Â© 2021, Springer Nature Singapore Pte Ltd.
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) 2025
Numerical analysis of polymer composites for actuation
(International Information and Engineering Technology Association, 2020) Hiremath, S.; Sangappa, V.; Rajole, S.; Kulkarni, S.M.
The design of a polymer composite actuator is essential for micro and nano applications. Thus, the composite material may deform or deflects as specific stimuli are applied, such as heat, electrical, light source, etc. The deformation of the composite material is caused by the type of stimulus applied. Hence, while it is heated, the expansion takes place quickly, and the heating is shut down, the material shrinks very slowly. In the present investigation, this phenomenon is mainly studied in the actuation of composite beams. Numerical analysis of carbon black filled polymer composite beam expansion, and contraction is being analyzed in this research. The structure of the beam has been created, and the composite properties are incorporated into the beam, and the uniform heat source is applied on to the surface of the beam. The heating and cooling of the composite material predict the increase and decrease in the temperature of the beam. The numerical analysis of the temperature-dependent expansion and contraction of the composite beam has been carried out successfully. An increase in temperature is observed to signify the slight expansion in the composite beam, whereas the contraction of the composite beam takes a longer time to reach room temperature. Also, the increase in the content of the filler leads to a decrease in the expansion of the composite beam. The numerical simulation of the polymer composite thus provides a solid platform for the experimental study of thermal actuators. © 2020 Lavoisier. All rights reserved.
Performance study of jute-epoxy composites/sandwiches under normal ballistic impact
(China Ordnance Society, 2020) Rajole, S.; Ravishankar, K.S.; Kulkarni, S.M.
This study is undertaken to explore the use of natural fiber Jute-epoxy (JE), Jute-epoxy-rubber (JRE) sandwich composite for ballistic energy absorption. Energy absorbed and residual velocities for these composites are evaluated analytically and through Finite Element Analysis (FEA). FE analysis of JE plates is carried out for different thicknesses (3, 5, 10 and 15 mm). JE plates and JRE sandwiches having the same thickness (15 mm) are fabricated and tested to measure residual velocity and energy absorbed. The analytical results are found to agree well with the results of FE analysis with a maximum error of 9%. The study on JE composite plate reveals that thickness influences the energy absorption. Experimental and FE analysis study showed that JRE sandwiches have better energy absorption than JE plates. Energy absorption of a JRE sandwich is about 71% greater than JE plates. Damages obtained from FEA and testing are in good agreement. SEM analysis confirms composites failed by fiber rupture and fragmentation. © 2019 The Authors
Physico-mechanical behavior of carbon black-infused polymer composite
(Springer, 2022) Hiremath, H.; Rajole, S.; Sondar, P.R.; Mathias, K.A.; Kulkarni, S.M.
This article deals with the development of polymer composites by incorporating carbon blacks (CBs) into polydimethylsiloxane (PDMS) matrix material for improving the mechanical and physical properties of the polymer composites. CBs of nano-size were used as filler material in varying volume percentages (5–25%), and the polymer composite was processed by solution casting method. Density, elastic modulus and hardness were measured in order to study the effect of the CB-reinforced PDMS matrix. Experimentally obtained mechanical properties were then compared with the standard empirical model. Density of the polymer composite was increased by five times as compared to the pure polymer material. With the increase in volume percentage of CB, both hardness and elastic modulus of the polymer composites were enhanced. Scanning electron microscope images of the composite material showed uniform distribution of CBs, implying strong binding with the matrix material, which attributed to improved mechanical properties. © 2021, Indian Academy of Sciences.
Study on ballistic energy absorption capability of glass-epoxy and jute-epoxy-rubber sandwich composites
(2018) Rajole, S.; Ravishankar, K.S.; Kulkarni, S.M.
High velocity impact analysis of natural fiber reinforced composites is essential as the trend is focused towards the development of light weight, environment-friendly, non-corrosive and economical materials. At present, the defence, aerospace and automobile sectors are using synthetic fiber composites which are expensive and non-eco-friendly. In the present study ballistic impact of jute-epoxy (JEC), glass-epoxy (GEC), jute-epoxy-rubber (JERC) sandwich composites are simulated with different thickness (1, 2 and 3 mm) and velocity variations (100, 200 and 300m/s) using Finite Element analysis software. Although different approaches to the analysis of the effect response of composite structures are available, numerical modeling is based on strict constitutive models is often preferred because it can provide valuable detailed information about the spatial and temporal distribution of damage during the impact. The ballistic parameters such as energy absorption, ballistic limit and fracture behaviors are predicted. The composite is made of 8 noded linear brick elements and the bullet/projectile is modeled as a discrete rigid element in which deformation behavior, energy absorption and penetration behaviors obtained are clearly represented. The simulation results predicted match well with the analytical results obtained. Among all the combination of the materials simulated, the sandwiches have better ballistic qualities. Energy absorption of sandwich(JERC) was found 67 percentage higher than GEC and 56 percentage higher than JEC laminate. In future, these materials can be the alternative materials for defence sector for bullet proofing. � 2018 Trans Tech Publications, Switzerland.
Study on ballistic energy absorption capability of glass-epoxy and jute-epoxy-rubber sandwich composites
(Trans Tech Publications Ltd ttp@transtec.ch, 2018) Rajole, S.; Ravishankar, K.S.; Kulkarni, S.M.
High velocity impact analysis of natural fiber reinforced composites is essential as the trend is focused towards the development of light weight, environment-friendly, non-corrosive and economical materials. At present, the defence, aerospace and automobile sectors are using synthetic fiber composites which are expensive and non-eco-friendly. In the present study ballistic impact of jute-epoxy (JEC), glass-epoxy (GEC), jute-epoxy-rubber (JERC) sandwich composites are simulated with different thickness (1, 2 and 3 mm) and velocity variations (100, 200 and 300m/s) using Finite Element analysis software. Although different approaches to the analysis of the effect response of composite structures are available, numerical modeling is based on strict constitutive models is often preferred because it can provide valuable detailed information about the spatial and temporal distribution of damage during the impact. The ballistic parameters such as energy absorption, ballistic limit and fracture behaviors are predicted. The composite is made of 8 noded linear brick elements and the bullet/projectile is modeled as a discrete rigid element in which deformation behavior, energy absorption and penetration behaviors obtained are clearly represented. The simulation results predicted match well with the analytical results obtained. Among all the combination of the materials simulated, the sandwiches have better ballistic qualities. Energy absorption of sandwich(JERC) was found 67 percentage higher than GEC and 56 percentage higher than JEC laminate. In future, these materials can be the alternative materials for defence sector for bullet proofing. Â© 2018 Trans Tech Publications, Switzerland.