Faculty Publications

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Now showing 1 - 7 of 7
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    Thermal Buckling of 3D Printed Auxetic Core Sandwich Beams
    (Springer, 2025) Dattam, V.K.; Pitchaimani, J.; Doddamani, M.
    Experimental investigation carried out on the thermal deflection behavior of 3D printed poly lactic acid sandwich beams possessing positive, negative, and zero Poisson’s ratio cellular cores is presented. Using a fused deposition modelling based 3D printer, sandwich beams were fabricated and investigated for thermal buckling under different heating conditions. Influence of Poisson’s ratio of the core and orientation of the beam on thermal buckling were also studied. It is found that Poisson's ratio of the core influences the thermal deflection of the beams remarkably. The sandwich beam having a vertically oriented core with zero Poisson's ratio exhibited superior buckling resistance compared to the other two cases. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
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    Experimental investigation of frequency and damping characteristics of magneto-rheological fluid core sandwich beams
    (American Institute of Physics Inc. subs@aip.org, 2020) Nagiredla, S.; Joladarashi, S.; Kumar, H.
    In dynamic systems mechanical vibration amplitudes may range from a few nanometres to meters. When the vibration amplitudes are high the system may lead to failure or lost it function. Structures often tend to failure because of the high vibration amplitudes. These vibrations can be reduced by changing the stiffness or damping of the structure. One of the approaches is semi-active damping achieved by using Magneto-rheological fluid (MRF) as core material in a sandwiched beam. Magneto-rheological(MR) fluids change from fluid state to quasi-solid state when it is activated by a magnetic field. Adding MR fluids to mechanical systems may significantly improve their dynamic response. This study aims to analyse the free vibration response of the cantilever sandwich beam filled with the MR fluid as core material with Magnetic field intensity. A sandwich cantilever beam with Composite material as face layer and Magneto-rheological fluid as core was fabricated. Free Vibration test is performed on a sandwich beam filled with MR fluid under the external magnetic field generated by permanent magnets. Magnitude of Viscoelastic moduli of the MR fluid increases with magnetic field intensity as the fluid becomes semi-solid. The aim of the work is to analyse the influence of Magneto-rheological effect on the beam response with respect to externally applied magnetic field. Vibrations of the beam are registered with magnetic field and without magnetic field strength. Obtained data is utilized to analyse the dependency of magnetic field strength on the beams natural frequency and damping. © 2020 Author(s).
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    Finite Element Formulation for Static and Time Dependent Transverse Deflection of Functionally Graded Sandwich Beams with Viscoelastic Core
    (Springer Science and Business Media Deutschland GmbH, 2023) Patil, R.; Joladarashi, S.; Kadoli, R.
    The present study describes the finite element (FE) formulation for static and time dependent deflection of functionally graded (FG) sandwich beams with viscoelastic core. The kinematics of the beam are derived as per Euler–Bernoulli beam model. Rule of mixture and power law index define the variation of properties of FG stiff layers and core is considered as isotropic. Standard Linear solid model is used to define time dependent shear modulus of viscoelastic material. Static deflection results are validated with available literature. Effect of parameters on static deflection are studied for various boundary conditions. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
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    Passive and Active Vibration Control of Hybrid Composite Sandwich Beam
    (Springer Science and Business Media Deutschland GmbH, 2024) Nagiredla, S.; Joladarashi, S.; Kumar, H.
    Vibration control is a rapidly developing field and research is being carried out on different methods to attenuate the harmful vibration levels. Composite materials carry the advantage of providing enhanced material properties compared to that of conventional materials. This work mainly focuses on conducting the transient analysis on hybrid composite sandwich beams with viscoelastic core and to implement the linear quadratic regulator (LQR) and Proportional, Integrate and derivative (PID) controllers. The transient response of the hybrid composite sandwich beam with the viscoelastic core is presented and the active vibration control study was implemented on the sandwich beam’s transfer function which is obtained by using system identification technique. It was found that there is a substantial change in settling time as well as vibrational amplitude. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.
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    Vibration analysis of fully and partially filled sandwiched cantilever beam with magnetorheological fluID
    (Taylor's University, 2020) Srinivasa, N.; Gurubasavaraju, T.M.; Kumar, H.; Arun, M.
    This paper presents the experimental and computational study on damping effect of the fully and partially filled sandwich cantilever beams. The sandwich beams referred as adaptive beams have a core layer filled with magnetorheological fluid (MRF) between two aluminium face plates. Forced vibration tests were conducted under different magnetic fields with the application of external force in the form of sinusoidal sweep excitation using an electrodynamic shaker. Effect on damping and natural frequency due to change in MR fluid core thickness of 2 mm, 4 mm and 6 mm for the fully filled beam and fluid core length of 75 mm, 150 mm and 250 mm for partially filled beam were investigated. Modal and harmonic analysis of the MR sandwich beams were carried out using FE analysis. The results indicated that in the case of the fully filled beam, a reduction in the natural frequency with the increase in MR fluid core thickness and a better damping at 2 mm fluid core thickness were observed. Also, in the case of the partially filled beam a reduction in natural frequency and improvement in damping is found with the increase in core length and magnetic field. The results of these analyses can be useful in designing the sandwich beams for structural application. © School of Engineering, Taylor's University
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    Dynamic response of a MRE sandwich structure under a non-homogenous magnetic field
    (Korean Physical Society, 2021) Poojary, U.R.; Hegde, S.; Kiran, K.; Gangadharan, K.V.
    A viscoelastic layer improves the response of a sandwich structure under dynamic loading. Through integration of a magneto-sensitive elastomer core, the adaptability of the structure over a wider frequency can be achieved. The current work focuses on the influence of a non-homogeneous magnetic field on a magnetorheological elastomer (MRE)-based sandwich cantilever beam. The dynamic response of the structure is measured using the impact hammer test as per the ASTM E-756-05 standard. Results revealed that the fundamental natural frequency of the MRE sandwich beam is a function of the intensity and the location of the non-homogenous magnetic field. The fundamental natural frequency is reduced as the magnitude of the magnetic flux density is increased or the magnetized region is shifted towards the fixed end. This unique response of the MRE sandwich beam under a non-homogenous magnetic field is an exception to the usual stiffness-enhancing behavior of a MRE. To study this disparity, we independently investigated the contributions by the localized stiffness enhancement and the deflection due to magnetic pull. The effect of the localized overall stiffness enhancement on the overall stiffness of the sandwich beam is investigated using modal analysis in ANSYS to analyze the variation in the fundamental frequency. The contribution due to magnetic pull is studied by performing an experimental modal analysis on an equivalent ferromagnetic cantilever beam deflected under the influence of a magnetic field. By comparing the experimental results and the corresponding investigation on the influencing factors, we confirmed that magnetic pull induced under non-homogenous magnetic field is an important parameter that significantly contributes to the dynamic response of a MRE sandwich beam. © 2021, The Korean Physical Society.
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    Influence of Material and Geometrical Properties on Static and Dynamic Behavior of MR Fluid Sandwich Beam: Finite Element Approach
    (Institute for Ionics, 2023) Nagiredla, S.; Joladarashi, S.; Kumar, H.
    Magnetorheological (MR) fluid can transform its rheological properties when it is exposed to a magnetic field. This nature of the MR fluid provides an additional stiffness and damping for the sandwich beam applications. The Lagrange’s method is used to derive the equations of motion for the current finite element formulation. The influence of an applied magnetic field, thickness ratio and the length parameter on the static deflection, loss factor and natural frequency for different boundary conditions are presented. Further, the study is extended to plot the real and imaginary mode shapes corresponding to the fundamental frequencies. The geometrical and material properties considered in the present study showed a significant influence on static deflection and vibration amplitude of the sandwich beam. There is a maximum of 22.74% decrease in static deflection obtained for the simply supported condition. © 2023, The Author(s), under exclusive licence to Shiraz University.