Faculty Publications
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Item Mechanical, Dynamic Mechanical and Vibration Behavior of Nanoclay Dispersed Natural Fiber Hybrid Intra-ply Woven Fabric Composite(Springer Science and Business Media B.V., 2016) RAJESH, M.; Jeyaraj, P.; Nagarajan, N.Influence of nanoclay dispersion on mechanical, dynamic mechanical and free vibration characteristics of basket type intra-ply woven banana/jute (banana yarn-weft direction, jute yarn-warp direction) hybrid polyester composite has been investigated. Results revealed that loading of nanoclay enhances the mechanical properties of the composite significantly as it improves the adhesion between fiber and matrix. Dynamic mechanical analysis result reveals that nanoclay addition significantly increases the storage modulus and glass transition temperature of the intra-ply hybrid composite. From free vibration studies, carried out on laminated beam like structures, it is found that the natural frequency of the composite laminate increases till 2 wt% of nanoclay while the modal damping increases when the wt% of nanoclay is more than 2. However, due to the agglomeration effect of nanoclay the properties are not improved for nanoclay loading beyond 2 wt%. © 2016, Springer Science+Business Media Singapore.Item Mechanical properties of fiber-reinforced concrete using coal-bottom ash as replacement of fine aggregate(Springer, 2019) Goudar, S.K.; Shivaprasad, K.N.; Das, B.B.The present investigation aims to study the significance of coal coal-bottom ash as a partial replacement to natural river sand in fiber-reinforced concrete (FRC). Hooked-end steel fibers were used to produce fiber-reinforced concrete at a fiber content of 1.5% by volume concrete. About 30% of natural sand was replaced with coal coal-bottom ash to produce M30 grade concrete with a water–cement ratio of 0.45. The prolonged curing period has a positive effect on the coal, coal-bottom ash replaced concretes. There was a slight increment in the compressive strength of FRC because of inclusion of steel fibers. However, significant improvements were observed in flexural and split tensile strength of FRC due to the inclusion of steel fibers. The optimum content of coal, coal-bottom ash replacement to natural sand was found to be 20%. © Springer Nature Singapore Pte Ltd. 2019.Item Mechanical properties of pavement quality concrete produced with reclaimed asphalt pavement aggregates(Springer, 2019) Panditharadhya, B.J.; Mulangi, R.H.; Ravi Shankar, A.U.; Kumar, S.Production of conventional coarse aggregates for concrete works is getting difficult because of depleting natural resources and environmental ill effects. Reclaimed Asphalt Pavement (RAP) aggregates, which are produced from asphalt waste generated during removal of flexible pavement. The disposal problems of asphalt waste generated is also addressed with this step. The properties of RAP aggregates may vary with the source of waste generation and the age of the asphalt. This study is taken up to determine the strength characteristics of pavement quality concrete produced with RAP aggregates produced with asphalt waste generated at local road construction site. Properties such as compression strength, elastic modulus, flexural strength, split tensile strength, and water absorption were determined for the specimen with varying percentage of RAP replacement. The asphalt waste was processed further with screening to obtain the required gradation. RAP aggregates were replaced with conventional aggregates by 20, 40, 60, 80, and 100%. Mix with 60% conventional granite aggregates and 40% RAP aggregates was found to satisfy the requirements of M30 grade concrete that can be used for producing concrete for constructing the roads with lower traffic volume. © Springer Nature Singapore Pte Ltd. 2019.Item Alkali-activated concrete systems: A state of art(Elsevier, 2020) Manjunath, R.; Narasimhan, M.C.Concrete is one of the most extensively used construction materials in the world. Production of ordinary Portland cement, the major constituent in the production of concrete, is leading to large-scale exploitation of the natural reserves of limestones, clays, and coal. It is estimated that there is a release of 0.8-1.0 tons of carbon dioxide to the atmosphere for the production of every ton of cement. In view of this, alternative construction materials are being developed, using industrial by-products such as fly-ash, ground granulated blast furnace slag, and metakaolin, which are generally rich in alumina and silica. The development of alkali-activated concrete systems has attracted the attention of concrete researchers in recent years. This chapter discusses the performance of alkali-activated concrete systems with different binders and alternate aggregates, in terms of their mechanical properties, durability, performance on exposure to elevated temperatures, performance on inclusion of fibers, and finally their suitability for use in structural members. © 2020 Elsevier Inc. All rights reserved.Item Structure and properties of short Areca fiber reinforced Maize PF composites(2009) Mohan Kumar, G.C.Mechanical properties of the fibers extracted from the areca are determined and compared with the other known natural fiber coir. Further these Areca fibers were chemically treated and the effect of this treatment on fiber strength is studied. Areca fiber composite laminates were prepared with randomly distributed fibers in Maize stalk fine fiber and Phenol Formaldehyde. Composite laminates were prepared with different proportions of phenol formaldehyde and fibers. Tensile test, moisture absorption test, and biodegradable tests on these laminates were carried out. Properties of these areca-reinforced phenol formaldehyde composite laminates were analyzed and reported. © 2009 American Institute of Physics.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.Item Microstructure and mechanical properties new magnesium-zinc-gadolinium alloys(Minerals, Metals and Materials Society 184 Thorn Hill Road Warrendale PA 15086, 2016) Seetharaman, S.; Tekumalla, S.; Lalwani, B.; Patel, H.; Bau, N.Q.; Gupta, M.Magnesium based materials are effective for structural/component weight reduction in automotive applications. However, their real time applications are limited because of their inadequate mechanical properties, especially the absolute strength and creep resistance. In this regard, the formation of thermally stable ternary compounds is believed to positively influence the properties of Mg-Zn-RE alloys. In this study, new Mg alloys containing Zn and Gd (Mg-2.0Zn-0.5Gd and Mg-3.4Zn-0.8Gd, in at.%) were developed using disintegrated melt deposition technique followed by hot extrusion. The developed alloys were investigated for their microstructural and mechanical properties in hot-extruded conditions. The mechanical properties examined under indentation, tension and compression loads indicated improved mechanical performance due to Zn and Gd addition. The observed mechanical properties are presented using structure-property relationship. © © 2016 by The Minerals, Metals & Materials Society. All rights reserved.Item Microstructure and mechanical properties of magnesium alloy processed by equal channel angular pressing (ECAP)(Elsevier Ltd, 2017) Gopi, K.R.; Shivananda Nayaka, H.Equal Channel Angular Pressing (ECAP) with different passes was carried out for Mg-Al-Mn (AM) series magnesium alloy to investigate the microstructure and mechanical properties. ECAP process was carried up to 4 passes using route BC, where the samples are rotated by 90° in the same direction between consecutive passes. Microstructures were studied using optical microscope (OM) and scanning electron microscope (SEM) and it was observed that the grain size was reduced from 100 μm to 1 μm after 4 passes. Tensile test was conducted and the ultimate tensile strength (UTS) increased up to 2 passes but decreased with higher passes, even though grain size became finer with increase in ECAP passes. Microhardness was carried out and it was observed that the hardness was increased up to 2 passes of ECAP and decreased with higher passes. © 2017 Elsevier Ltd.Item Microstructural characterization and mechanical properties of cast Al-15Zn-2Mg alloy subjected to severe plastic deformation(Elsevier Ltd, 2018) Manjunath, G.K.; Udaya Bhat, K.; Preetham Kumar, G.V.In the present work, Al-15Zn-2Mg alloy was processed by ECAP technique for grain refinement. The ECAP processing was conducted at 150 °C. Microstructural characterization was carried out in OM, SEM, TEM and XRD. To evaluate the mechanical properties, hardness measurement and tensile tests were conducted at room temperature. Microstructural characterization showed that, ECAP processing leads to decrease in the grain size of the alloy. Also, small amount of dislocations were also observed in the ECAP processed material. After ECAP processing, precipitates nucleation in the material was identified in the XRD analysis. The strength and the hardness values were increased after ECAP processing. After ECAP processing, microhardness of the material is increased from 173 Hv to 252 Hv and the UTS of the material is increased from 166 MPa to 362 MPa. After tensile testing, fracture surface of the cast material showed dendritic structure and the fracture surface of the ECAP processed material showed dimples. © 2018 Elsevier Ltd. All rights reserved.Item Influence of Multi Axial Forging (MAF) on Microstructure and Mechanical Properties of Cu-Ti Alloy(Elsevier Ltd, 2018) Ramesh, S.; Shivananda Nayaka, H.S.; Gopi, K.R.Multi axial forging (MAF) is one among the severe plastic deformation (SPD) processes, where large strains are imposed into the component. In the present work, as-received Cu-1.5%Ti alloy was subjected to MAF for 2 and 4 cycles at room temperature. Microstructure showed grain refinement after 2 and 4 cycles. Average grain size obtained for MAF processed samples after 2 and 4 cycles are 120 μm and 40 μm, respectively compared to initial grain size of 800 μm. The Mechanical properties were analyzed for as-received and MAF processed samples. Tensile test showed increased ultimate tensile strength (493 MPa) for MAF 4-cycle sample compared to as-received (191 MPa) condition with accumulated strain of 2.18 for 4 cycles. Increase in hardness was observed for MAF processed sample of 143 Hv for 4-cycle compared to as-received sample of 67 Hv. © 2018 Elsevier Ltd.