Conference Papers

Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506

Browse

Has files: NoSubject: search.filters.subject.Epoxy

Search Results

Now showing 1 - 10 of 10
  • No Thumbnail Available
    Item
    Bending strength of cenosphere foam cored jute/glass skin sandwiches
    (2004) Kulkarni, S.M.; Sandesh, S.; Sharnappa
    Sandwich construction is widely used in structural application because of its high bending stiffness coupled with lightweight. In design of sandwiches, skin made of high modulus of elasticity is used with core of high shear modulus. This balance is important so that neither material fails long before the other is stressed to accepted level. In the present study, experiments have been carried out on polymeric foam core sandwich beams with jute/epoxy faces. Syntactic polymeric foam cores, which have high compressive strength compared to open cell foams are made by mixing hollow fly-ash particles called cenospheres in a matrix material. The variable considered is the density of the core varied by differing the volume fraction of cenospheres. Cenospheres used in the present study are obtained from flyash, a waste byproduct of thermal power plants using a low cost separation process. Cores with four different volume fractions are prepared and sandwiched between a set of jute fabric layers. It is noticed that as volume fraction of cenospheres increased density is decreasing (1.12 to 0.98 g/cm3). The sandwich beams cut from the samples are tested using standard three-point bending procedure and the results obtained are compared with the results of glass skin sandwich with similar cores. Results showed a large difference in specific strengths of glass and jute skin sandwiches, which could be attributed to high tensile strength of glass fiber compared to jute fiber. There is a decrease of about 13% and 8% from the maximum specific strength for glass skin and jute skin sandwiches respectively at higher volume fractions of cenospheres. This could be traced to the failure of core well before the skin is stressed to accepted level in case of glass skin sandwiches. The jute skin sandwiches exhibited a little flatter specific strength response with respect to volume fraction of cenospheres indicating matching of the features pertaining to jute skin and the core properties. As the specific strength per unit cost of jute approaches that of glass, jute may be used to replace glass fiber with a significant cost advantage for less demanding applications.
  • No Thumbnail Available
    Item
    Mechanical and tribological behaviour of epoxy reinforced with nano-Al2O3 particles
    (Trans Tech Publications Ltd ttp@transtec.ch, 2014) Kurahatti, R.V.; Surendranathan, A.O.; Ramesh Kumar, A.V.; Auradi, V.; Wadageri, C.S.; Kori, S.A.
    In the present work systematic study has been conducted to investigate the matrix properties by introducing nanosize Al2O3 (particle size 100 nm, 0.5-10 wt %) fillers into an epoxy resin. High shear mixing process was employed to disperse the particles into the resin. The experimental results indicated that frictional coefficient and wear rate of epoxy can be reduced at rather low concentration of nano-Al2O3. The lowest specific wear rate 0.7 × 10-4 mm3/Nm is observed for the composites with 1 wt.% which is decreased by 65% as compared to unfilled epoxy. The reinforcement of Al2O3 particles leads to improved mechanical properties of the epoxy composites. The results have been supplemented with scanning electron micrographs to help understand the possible wear mechanisms. © (2014) Trans Tech Publications, Switzerland.
  • No Thumbnail Available
    Item
    Physical, mechanical and sliding wear behavior of solid glass microsphere filled epoxy composites
    (Elsevier Ltd, 2018) Agrawal, A.; Chandraker, S.; Sharma, A.
    Performance of epoxy based composites filled with micro-size solid glass microsphere (SGM) is reported in this work. The main emphasis of the present work is on the common trends detected in properties of epoxy/SGM composites. For physical property, densities of all the fabricated samples were presented.Glass micro-sphere filled epoxy composites haveless porosity. They also exhibit improvedmicro-hardness, flexural and impact strength, though tensile strength is compromised marginally. Further, sliding wear performance of the fabricated composites with respect to filler content, sliding velocity and applied force were studied.With improved physical, mechanical and sliding wear, the presently fabricated composites found its potential application where wear predominated. © 2018 Elsevier Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    Flexural modulus of epoxy composite reinforced with Arecanut husk fibre (AHF): A mechanics approach
    (Elsevier Ltd, 2019) Muralidhar, N.; Kaliveeran, V.; Arumugam, V.; Srinivasula Reddy, I.
    Arecanut Husk Fibre (AHF) is an agricultural waste material. Polymer composites prepared with AHF as reinforcing material avoids dumping of arecanut husk onto bare land. AHF contributes to the development of innovative products having low environmental impact. These polymer composites are cost-effective and have low-density. Composites manufactured using polymers and natural fibre are widely used in aerospace, automobile, construction and marine structural applications. AHF was extracted by chemical retting process using 6% sodium hydroxide solution. The present research focuses on composite panel preparation using epoxy reinforced with treated AHF (15% by weight of composite) and flexural characterization of the composite. Composites were made with three-layered arrangement of AHF threads. In the current study, flexural modulus of AHF composite panels is determined by conducting dynamic flexural tests with fixed-fixed support condition and at different loading frequencies. The flexural modulus of the composite material is calculated using Euler-Bernoulli bending theory and results are compared with existing literature. © 2019 Elsevier Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    Dynamic Mechanical Analysis and Thermal Stability of Neem Wood Veneer Plastic Composites
    (Elsevier Ltd, 2019) Nagamadhu, M.; Vijay Kumar, S.; Ravi Kumar, S.; Suraj, R.; Kumar, G.C.
    The neem wood veneer is used as core materials in many of the wood structural applications. In this research work, neem wood polymer composite (NWPC) were prepared to understand the effect of weight fraction, stacking sequence, and interfacial bonding between neem wood veneer and epoxy material. NWPC were prepared conventional compression molding and Thermo-mechanical properties of wood epoxy composite samples were investigated by the dynamic mechanical analyzer over the temperature range from 30 to 180°C. Storage modulus (G') and Loss modulus (G") of NWPC samples exhibited significant effect with respect weight fraction of wood veneer. Similarly epoxy has good interfacial bonding agent to enhance the strength of multilayered wood polymer composites. However, the stacking sequence having major changes in dynamic mechanical properties, G' & G" increases along the wood fiber direction with negligible load bearing capacity in transfers direction. By changing the orientation of the wood veneer properties improved in both the direction. Additionally, scanning electron microscopy (SEM) evidently shows the interfacial bonding efficiency. © 2019 Elsevier Ltd.
  • No Thumbnail Available
    Item
    Comparative study on energy absorbing behavior of stiff and flexible composites under low velocity impact
    (American Institute of Physics Inc. subs@aip.org, 2019) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.
    This paper deals with the comparative study on the energy absorbing behaviour of the flexible composites with that of stiff composites aiming at automobile cladding application. Two types of composites namely Jute-Epoxy (JE) laminate and Jute-Rubber-Jute (JRJ) sandwich are chosen for the purpose of study under impact velocity varying from 2.5 m/s to 10 m/s. The study is carried out using commercially available finite element simulation software. The energy absorption and damage behavior of both the composites are studied. From the results, it was found that JRJ sandwich absorbs almost 54%, 51.2%, 58.1% and 61.78% more energy compared to JE laminate for impact velocity of 2.5 m/s, 5 m/s, 7.5 m/s and 10 m/s respectively and exhibits compliant nature as opposed to JE laminate which exhibits brittle nature. The energy absorption ratio of JRJ sandwich is more compared to JE laminate. Thus, the JRJ sandwich composites are expected to provide better energy absorption, reduce damage propagation under low velocity impact, thereby making them a potential material for automobile structural protective claddings. © 2018 Author(s).
  • No Thumbnail Available
    Item
    Experimental investigations on hole quality in drilling of cenosphere reinforced epoxy composite
    (Institute of Physics Publishing helen.craven@iop.org, 2019) Angadi, S.B.; Ashrith, H.S.; Gaitonde, V.N.; Karnik, S.R.; Doddamani, M.
    Cenosphere reinforced epoxy composites are steadily replacing the conventional materials in marine, aerospace and automobile structuresowing to their lightweight properties.Drilling is an important conventional machining process essential for assemblyof polymer composites using rivets and bolts. Drilling induces damage around the hole which significantly deteriorates composite performance. In the present study, hole quality characteristicssuch as cylindricity and delamination in drilling of fly ash cenosphere filled epoxy composites are investigated using coated tungsten carbide drill bits.Feed, cutting speed, filler content and drill diameter are considered as the drilling process variables.Samples are fabricated by varying cenosphere content from 10to 60by volume %inepoxy resin.Full factorial design (FFD) based experiments are conducted on CNC vertical machining center. Response surface methodology (RSM) based mathematical models are proposed to estimate the characteristics of the hole quality in developed composites. Analysis of variance is used to validate the developed mathematical models.Present study reveals that the cylindricity and delamination decreases with increasing feed. Increasing cutting speed decreases the cylindricity, however delamination is found to be increasing.Results also shows the importance of using high cenosphere content for producing sound quality holes, which is also beneficial from weight savingperspective. © 2019 IOP Publishing Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    Study on ballistic characteristics of glass-epoxy-rubber sandwiches
    (Trans Tech Publications Ltd ttp@transtec.ch, 2020) Sangamesh, R.; Hiremath, H.; Ravishankar, K.S.; Kulkarni, S.M.
    This article focuses on the Finite Element (FE) analysis of the ballistic performance of the polymer composites. These composites consisting of natural rubber (NR), glass-epoxy (GE) and glass-rubber-epoxy (GRE) sandwich of different thicknesses (3, 6 and 9 mm) under the impact of the conical nose projectile for a velocity variation of (180, 220 and 260 m / s). FE modeling was carried out to forecast the energy absorption, ballistic limit velocity and failure damage mode of the target material. The significant influence of thickness, interlayers and sandwiching effect was studied: the lowest ballistic limit was obtained for 3 mm thick GE. The energy absorption capacity of GRE sandwich was highest among the natural rubber and GE. The work can be extended for the experimental validation purpose so that these polymer composite materials could be utilized in the defense sector for bullet-proofing. © 2020 Trans Tech Publications Ltd, Switzerland.
  • No Thumbnail Available
    Item
    Study on Physical and Mechanical Behavior of Bauhinia Vahlii Fiber Filled Glass–Epoxy Hybrid Composites
    (Springer Science and Business Media Deutschland GmbH, 2023) Ray, R.; Das, S.N.; Mohapatra, A.
    Epoxy is well-suited for a number of industrial applications because of its versatility and its diversity. In many high-performance fields however, the overall use of epoxy limited its employment due to delamination, intrinsic fragility, low impact resistance and hardness to fractures. Epoxy's limitations can be overcome through inclusion and modification prior to industrial use. The present research describes the development of hybrid composites made of epoxy reinforced with glass fiber and filled with Bauhinia Vahlii fiber. Bauhinia Vahlii (BV) found to be most promising natural fiber for manufacturing composites for its superior mechanical as well as thermal properties. In this study, the incorporation of BV fiber on physical and mechanical behavior of glass–epoxy composites was investigated. Various composite compositions with three distinct natural BV fiber percentages (4, 8, 12%) were fabricated using a hand layup technique. The results showed that increasing the percentage of natural fiber concentration improves mechanical qualities, however at larger BV fiber loading, the strength reduces due to presence of more voids which signifies poor bonding. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
  • No Thumbnail Available
    Item
    Short term creep behavior of neem wood veneer epoxy composites
    (American Institute of Physics Inc., 2023) Nagamadhu, M.; Kivade, S.B.; Vijay Kumar, S.V.; Kumar, G.C.M.
    Neem wood used many structural applications due to its coarse grain with interlocking fibers leads to excellent mechanical properties with a very good life. However, wood structures are exposed to various environmental conditions, so it is necessary to investigate the effect of time and temperature for different stacking sequences. This paper aims to explore the importance of time and temperature of neem wood veneer epoxy composites at various stacking sequence and interfacial bonding. The Dynamic Mechanical Analyzer used to study short term creep at a nitrogen environment using a three-point bending condition. The result shows neat neem wood veneer exhibit a higher percentage of strain as compared to neem wood epoxy composites. On the other hand, the stacking sequence having significant changes in dynamic mechanical and creep studies, storage modulus (G') & loss modulus (G'') increases along the wood fiber direction with minor load-bearing capacity in lateral direction. By varying the orientation of the wood veneer mechanical and thermo-mechanical properties improved in both longitudinal and lateral direction. © 2023 Author(s).