Faculty Publications
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Item Investigation of the effect of BaTiO3/CoFe2O4 particle arrangement on the static response of magneto-electro-thermo-elastic plates(Elsevier Ltd, 2018) Mahesh, M.; Kattimani, S.In this article, a framework based on finite element (FE) methods is proposed for predicting the influence of spatial arrangement of two phase Barium Titanate (BaTiO3) and Cobalt Ferric Oxide (CoFe2O4) particulate composites on the static response of magneto-electro-thermo-elastic (METE) plates. The coupled material properties such as piezoelectric, piezomagnetic, dielectric, magnetic permeability, thermal expansion and pyro co-efficients vary significantly with the spatial arrangement of BaTiO3/CoFe2O4 particulates. The coupled FE governing equations accounting the effect of particle arrangement is presented by incorporating linear coupled constitutive equations of METE composites. Through the condensation technique, the governing equations of METE plates are solved to obtain direct (thermal displacements, electric and magnetic potentials) and derived quantities (stresses, electric displacements and magnetic flux densities). A special attention has been placed on evaluating the pyro-electric and pyro-magnetic coupling effects for different packing arrangement considered namely, Body Centered Cubic (BCC), Face Centered Cubic (FCC) and Simple Cubic (SC) METE particulate composites. Further, parametric studies are carried out to analyse the influence of boundary conditions and aspect ratio. The present study reveals that the multiphysics response of METE plates changes significantly with the packing arrangements of BaTiO3/CoFe2O4 particulates and geometrical parameters. It is believed that the obtained solutions would provide insights into design aspects of METE structures. © 2017 Elsevier LtdItem 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 LtdItem Finite element simulation of controlled frequency response of skew multiphase magneto-electro-elastic plates(SAGE Publications Ltd info@sagepub.co.uk, 2019) Mahesh, M.; Kattimani, S.The linear frequency response of skew multiphase magneto-electro-elastic composite plate embedded with active constrained layer damping treatment has been studied. The volume fraction of piezoelectric fibres embedded in the piezomagnetic matrix significantly affects the coupling characteristic of this multiferroic material, and hence, the frequency of the skew multiphase magneto-electro-elastic plate is drastically altered. This study emphasizes on evaluating the influence of different volume fraction of barium titanate (BaTiO3) and cobalt ferrite (CoFe2O4) on the frequency characteristics of skew multiphase magneto-electro-elastic. In this regard, a finite element formulation has been proposed to assess the damped response of such skew multiphase magneto-electro-elastic plates. Incorporating the complex modulus approach, the constrained viscoelastic layer of the active constrained layer damping patch is modelled. In addition, the effect of geometrical skewness has also been investigated. Meanwhile, an exhaustive parametric study is carried out to analyse the influence of control gain, patch position and fibre orientation angle of piezoelectric composite. © The Author(s) 2019.Item Static, buckling, and free vibration characteristics of porous skew partially functionally graded magneto-electro-elastic plate(Taylor and Francis Ltd., 2023) Kiran, K.; Wang, W.; Fang, C.; Kattimani, S.In this article, a new mathematical model to develop porous skew partially functionally graded (SPFG) magneto-electro-elastic (MEE) plate from a stepped functionally grade (SFG) plate is proposed. The combination of Barium Titanate (BaTiO3) and Cobalt Ferrite (CoFe2O4) is graded stepwise to achieve SFG plates. Such, SFG plate is approximated using modified power law for functional variation through its thickness. Modified first-order shear deformation theory (FSDT) is deployed in the current study to develop mathematical models. The geometrical modification from rectangular to skew plate is achieved using transformation matrix. Porosity in the partial functionally graded MEE plate is taken as local density. Free vibration study is carried out to reflect the influence of partial gradation, porosity distribution, porosity volume, and skew angle on the natural frequency of porous SPFG MEE plate. The influence of various types of porosity distribution, partial gradation, and skew angle on the primary quantities such as displacements, potentials, and secondary quantities such as stresses, electric displacement, and magnetic induction on SPFG MEE plate is studied. The stability characteristics of the SPFG MEE plate are also investigated to study the buckling behavior under various porosity distributions, partial gradation, and skew angles. The effect of change in aspect ratio, and thickness ratio on the free vibration and static behavior is also investigated. © 2021 Taylor & Francis Group, LLC.Item Effect of BTO piezoceramic on the mechanical and dielectric properties of 3D-printed PLA.BTO functional polymer composite(Springer Nature, 2025) Senthil Murugan, S.; Kattimani, S.; Saminathan, R.The development of polymer composite materials for additive manufacturing is critical for advancing industrial applications. This study enhances the functional performance of poly-lactic acid (PLA) by incorporating barium titanate (BTO/BaTiO?) particles. Uniform dispersion of BTO within the PLA matrix was achieved, and filaments were fabricated using fused deposition modelling (FDM) with a 60% infill rate, adhering to ASTM standards. The influence of BTO fillers on the mechanical and dielectric properties of PLA.BTO composites were analysed and compared to pure PLA. FESEM microstructural analysis confirmed distinct layering, defect-free deposition, and uniform BTO distribution. Mechanical testing revealed notable improvements, including increases in tensile strength (16.4%), flexural strength (17.1%), shore hardness (4.7%), impact strength (17.7%), and drop-weight energy absorption for a 5 mm plate (26%), attributed to enhanced interfacial bonding and reduced void formation. The dielectric properties exhibited significant enhancements, with a 12.9% increase in dielectric strength, a 15% higher dielectric constant, an 8% greater breakdown strength, and a 21.74% rise in electrical susceptibility. Furthermore, reductions in loss tangent (19.1%), AC conductivity (7.8%), and dielectric loss (6.8%) demonstrated the material’s ability to store and withstand electric fields efficiently. Ferroelectric analysis revealed improved remanence, coercivity, and polarization, underscoring the composite’s potential as a piezoelectric material. These findings highlight the suitability of PLA.BTO composites for energy storage devices, sensors, and biodegradable functional applications, offering a promising balance of mechanical durability and superior dielectric performance. © Qatar University and Springer Nature Switzerland AG 2025.Item Effect of piezoelectric ceramic on natural frequency, structural, and thermal properties of additively manufactured PLA/BTO composite structure(Elsevier Ltd, 2025) Senthil Murugan, S.S.; Kattimani, S.This study investigates the fabrication and characterisation of filaments and 3D-printed samples using polylactic acid (PLA) and PLA/BTO (Barium Titanate) composites via fused deposition additive manufacturing (FDAM). PLA/BTO composite filaments were prepared by blending PLA granules with BTO particles using hot extrusion. Samples were 3D printed under controlled parameters and analyzed for dynamic, thermal, and structural properties. The inclusion of BTO significantly enhanced natural frequency (11 Hz-first peak) and structural rigidity compared to pure PLA (8 Hz-first peak), particularly under cantilever beam configurations. Microstructural analysis via optical and field emission scanning electron microscopy (FESEM) revealed uniform particle dispersion and good layer adhesion in composites with a peak width of 340 ?m. Energy-dispersive X-ray diffraction (EDS) study insisted that the presence of BTO improves functionality with minimal reinforcement with other trace elements. X-ray diffraction (XRD) confirmed increased crystallinity in PLA/BTO samples and improved alignment of the crystalline regions post-FDAM process, while Fourier transform infrared spectroscopy (FTIR) demonstrated molecular interactions between PLA and BTO and highlights the structural modifications in the composite due to the act of BTO reinforcement as nucleating agent. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) highlighted enhanced thermal stability and modified crystallinity due to BTO incorporation. Printed PLA/BTO demonstrates the highest resistance to thermal degradation than pure PLA, with degradation onset at an elevated temperature. Results validate the suitability of PLA/BTO composites for applications requiring tailored dynamic, thermal, and structural properties, emphasizing the FDAM process's potential for advanced material development. © 2025 Elsevier Ltd and Techna Group S.r.l.Item Investigation of dielectric properties and shore hardness of 3D-printed PLA core sandwich disc with functional ceramics surface cladding(KeAi Publishing Communications Ltd., 2025) Senthil Murugan, S.S.; Kattimani, S.; Bharadwaj, N.Poly-lactic acid (PLA), a popular biodegradable polymer for 3D printing, has limited dielectric strength and surface hardness, restricting its use in advanced electronic and structural applications. Existing enhancement methods are often complex or yield inconsistent results. Therefore, a straightforward and scalable approach is necessary to enhance the properties of 3D-printed PLA. This study aims to explore the enhancement of the dielectric and surface hardness of printed PLA discs through surface cladding using nano-functional ceramics and graphene for next-generation multifunctional applications. PLA discs were fabricated via Fused Deposition Modelling (FDM) and subsequently cladded using hand layup with Araldite resin as a binder. Cladding materials included cobalt ferrite (CF), barium titanate (BTO), and graphene (Gr), individually and in combinations. Dielectric properties—capacitance, impedance, dielectric constant, dielectric loss, dissipation factor, and AC conductivity—were analyzed using an impedance analyzer, while surface hardness was measured using a Shore-D durometer. Results revealed that cladding led to uniform particle dispersion with effective surface bonding, improved dielectric performance, and significantly enhanced surface hardness. The CF + BTO + Gr combination exhibited superior dielectric behaviour, balancing high polarization with low energy dissipation, while BTO contributed to an enhanced dielectric constant and graphene improved charge transfer. All cladded samples showed frequency-dependent dielectric responses, with stability at higher frequencies. The highest surface hardness was achieved with CF + BTO, attributed to rigid, uniform reinforcement. © 2025 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltdé This is an open access article under the CC BY-NC-ND license. http://creativecommons.org/licenses/by-nc-nd/4.0/Item Surface characteristics of 3D-printed PLA/BTO piezo-polymer composite(Springer Science and Business Media Deutschland GmbH, 2025) Senthil Murugan, S.S.; Kattimani, S.3D printing has emerged as a transformative technology for fabricating multiphase composite materials with tailored properties for advanced industrial applications. However, the influence of functional particle reinforcement on the surface morphology of printed bioplastics remains underexplored. This study addresses the research question: How does the incorporation of piezoelectric barium titanate (BaTiO3, BTO) particles affect the surface characteristics of 3D-printed poly-lactic acid (PLA) composites? To investigate this, a novel bioplastic composite filament was developed by extruding PLA with BTO particles, and composite specimens (PLBT) were fabricated using a 3D printing method-fused filament fabrication (FFF). A comprehensive surface characterization was performed using 3D non-contact profilometry, analyzing parameters including line and areal surface roughness, furrow formation, isotropy, peak count histograms, polar angle circular mean, mean resultant length (MRL), and Bearing Area Curve (BAC). Comparative analysis between pure PLA and PLBT samples, as well as between their top and bottom printed surfaces, revealed that the inclusion of BTO particles significantly altered the deposition behavior, resulting in increased surface roughness and distinct topographical features. Specifically, average surface roughness values increased from 8.2 µm in pure PLA to 15.8 µm in PLBT composites. The top surfaces of PLBT samples exhibited smoother textures with smaller peaks and valleys, which are advantageous for wear-sensitive applications. These findings contribute to the limited body of knowledge on the surface behavior of 3D-printed functional composites and highlight the critical role of particle reinforcement in tuning surface performance for application-specific demands. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.