Faculty Publications

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Publications by NITK Faculty

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Author: search.filters.author.Kattimani, S.Subject: search.filters.subject.Reinforcement

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Now showing 1 - 7 of 7
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    Vibration control of multiferroic fibrous composite plates using active constrained layer damping
    (Academic Press, 2018) Kattimani, S.; Ray, M.C.
    Geometrically nonlinear vibration control of fiber reinforced magneto-electro-elastic or multiferroic fibrous composite plates using active constrained layer damping treatment has been investigated. The piezoelectric (BaTiO3) fibers are embedded in the magnetostrictive (CoFe2O4) matrix forming magneto-electro-elastic or multiferroic smart composite. A three-dimensional finite element model of such fiber reinforced magneto-electro-elastic plates integrated with the active constrained layer damping patches is developed. Influence of electro-elastic, magneto-elastic and electromagnetic coupled fields on the vibration has been studied. The Golla–Hughes–McTavish method in time domain is employed for modeling a constrained viscoelastic layer of the active constrained layer damping treatment. The von Kármán type nonlinear strain-displacement relations are incorporated for developing a three-dimensional finite element model. Effect of fiber volume fraction, fiber orientation and boundary conditions on the control of geometrically nonlinear vibration of the fiber reinforced magneto-electro-elastic plates is investigated. The performance of the active constrained layer damping treatment due to the variation of piezoelectric fiber orientation angle in the 1–3 Piezoelectric constraining layer of the active constrained layer damping treatment has also been emphasized. © 2018 Elsevier Ltd
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    On vibration analysis of functionally graded carbon nanotube reinforced magneto-electro-elastic plates with different electro-magnetic conditions using higher order finite element methods
    (China Ordnance Industry Corporation, 2021) Mahesh, M.; Harursampath, D.; Kattimani, S.
    This article deals with evaluating the frequency response of functionally graded carbon nanotube reinforced magneto-electro-elastic (FG-CNTMEE) plates subjected to open and closed electro-magnetic circuit conditions. In this regard finite element formulation has been derived. The plate kinematics adjudged via higher order shear deformation theory (HSDT) is considered for evaluation. The equations of motion are obtained with the help of Hamilton's principle and solved using condensation technique. It is found that the convergence and accuracy of the present FE formulation is very good to address the vibration problem of FG-CNTMEE plate. For the first time, frequency response analysis of FG-CNTMEE plates considering the effect of various circuit conditions associated with parameters such as CNT distributions, volume fraction, skew angle, aspect ratio, length-to-thickness ratio and coupling fields has been carried out. The results of this article can serve as benchmark for future development and analysis of smart structures. © 2020 The Authors
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    Study of mechanical and dynamic mechanical behavior of halloysite nanotube-reinforced multiscale syntactic foam
    (John Wiley and Sons Inc, 2021) Bakshi, M.S.; Kattimani, S.
    The present study deals with the development of novel cenosphere-epoxy multiscale syntactic foam (MSF) reinforced with halloysite nanotubes (HNTs). Cenospheres with different volume fractions (0, 20, 30, 40, 50 vol%) and HNTs (1 vol%) used in the fabrication of syntactic foams. The addition of HNTs increases the tensile modulus (42%) and flexural modulus (66%) compared with plain syntactic foam (PSF). Furthermore, FTIR studies reveal the strong hydrogen bonding interaction between HNTs and epoxy. Field emission scanning electron microscopy (FESEM) confirms the unique crack deflection phenomenon by HNT, which indicates the structure–property correlation. In addition, the storage and loss modulus of MSFs is 36 and 113%, respectively (at 30°C) higher than the neat epoxy. Improvement in the tensile and flexural properties along with excellent thermal stability at elevated temperature makes MSF a promising material for structural, weight-sensitive, and high-temperature applications. © 2020 Wiley Periodicals LLC
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    Effect of temperature on the performance of active constrained layer damping of skew sandwich plate with CNT reinforced composite core
    (Taylor and Francis Ltd., 2022) Kallannavar, V.; Kattimani, S.
    In this paper, the first attempt has been made to investigate the performance of the active constrained layer damping system in the thermal environment. For such investigation, a skew laminated composite sandwich plate with carbon nanotube-reinforced composite core is considered. The nonlinear strain-displacement relations are employed to generate the initial-stress stiffness matrix and the mechanical stiffness matrices using linear strain-displacement relations. The negative velocity feedback control-law is used to control the first few modes of the vibrating sandwich plate. Comprehensive investigation has been carried out to understand influence of geometric and material parameters on the damping performance of the system. © 2021 Taylor & Francis Group, LLC.
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    Probing the effect of post-curing and halloysite nanotube reinforcement on thermo-mechanical properties of lightweight epoxy syntactic foam composites
    (SAGE Publications Ltd, 2023) Bakshi, M.S.; Kattimani, S.
    This paper deals with an investigation of the post-curing effect of halloysite nanotubes (HNTs) reinforced syntactic foam (HRSF) containing cenosphere as hollow inclusion at 0, 20, and 40 vol% in an epoxy matrix. Compression, flexural, and thermal properties of HRSF (1 vol% HNTs) and cenosphere/epoxy syntactic foam (CESF) composites without HNTs are studied under the influence of post-curing. Further, the post-cured HRSF containing 40 vol% cenosphere (NSF40_H) exhibited a compressive modulus of 33.2% higher than room temperature cured neat epoxy due to improved crosslinking. Addition of HNTs in NSF40_H augments the flexural modulus up to 26.9% compared to post-cured neat epoxy. Additionally, the glass transition temperature (Tg) of CESF composites with 40 vol% cenosphere was increased by 24.3 °C compared to the room temperature cured sample. This positive shift in Tg can be attributed to the beneficial impact of post-curing, as indicated by differential scanning calorimetry study. Thermogravimetric results demonstrated better thermal stability of HRSF relative to CESF and neat epoxy composites. Transmission electron microscopy illustrated the structure-property correlations of nanotube reinforcement. The improved properties of syntactic foams could be viewed as a potential material for lightweight constructions, especially in the marine and automobile industries. © IMechE 2022.
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    Influence of moisture absorption on the compressive behavior of halloysite nanotube reinforced buoyant nanocomposite foams for maritime applications
    (John Wiley and Sons Inc, 2023) Bakshi, M.S.; Kattimani, S.
    Current research focuses on the development of buoyant nanocomposite foams comprising naturally available nanofiller-halloysite nanotubes (HNTs). Cenosphere, a waste byproduct of thermal power plants, is used to impart lightweight properties to syntactic foam composites at 0, 20, and 40 vol% in an epoxy matrix. HNTs are added to the cenosphere epoxy syntactic foam (CESF) composites at a constant 1 vol% to improve the favorable mechanical and water absorption properties of the composites. To evaluate the mechanical response of the CESF and HNTs reinforced syntactic foam (HRSF) composites, compression tests are conducted on samples immersed in water. The results of the water absorption analysis on the CESF and HRSF composites conclude that HNTs inhibit the entry of water into the epoxy matrix, resulting in lower absorption values in HRSF samples than in CESF. Outcomes from the compression tests and FTIR study support this conclusion. The modulus value of the water-immersed HRSF sample with 40% cenospheres (NSF40 W) is reduced by 26.35%, and a 48.52% reduction in the modulus is registered for CESF with a similar concentration without HNTs. Structure–property correlations are established using the crack-pinning phenomenon and planar dispersion of HNTs depicted by transmission electron microscopy. The HNTs reinforcement shows great promise as a structural, buoyant, and lightweight syntactic nanocomposite foam for maritime applications. © 2023 Society of Plastics Engineers.
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    Tribological performance and 3-D surface characterisation of age-hardened Al2090-based ceramic composites
    (SAGE Publications Ltd, 2025) Sharath, B.N.; Mahesh, V.; Mahesh, V.; Kattimani, S.; Harursampath, D.
    This study investigates the synergistic influence of boron nitride (BN) tertiary ceramic additives and age-hardening treatment on the microhardness and wear resistance of Al2090-based hybrid composites, fabricated using the stir casting method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) studies are carried out to assess the phases present, microstructure, and surface properties, respectively. The metallurgical investigations confirm a relatively superior uniformity in the distribution of particles and the ageing of precipitation at 150°C, vis-à-vis the other temperatures explored in this study. The experimental examinations conducted as per ASTM (E8 and G99) standards revealed a significant improvement in both the hardness and the primary tribological properties, when micron-sized boron carbide, graphite, and boron nitride were used as reinforcements. Age-hardened samples, especially the hybrid composite HS-2 with 5 wt.% each of boron carbide, graphite, and boron nitride, demonstrated an enhanced hardness of 25.23% and lower surface roughness (44.3 nm) compared to Al2090 (AS), due to the presence of load-bearing ceramic reinforcements. Increasing the applied load led to higher wear rates and coefficients of friction for Al2090. However, heat-treated hybrid metal matrix composites (HMMCs) exhibited a contrary behaviour, suggesting enhanced durability. The investigation highlighted the better wear resistance of heat-treated and near-optimally reinforced HMMCs, indicating their potential candidature for wear-resistant aerospace applications. © IMechE 2025.