Faculty Publications
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Item A comparison of the non-conforming and conforming sector finite element for free vibration of circular discs(Elsevier Ltd, 2020) Avvaru, H.T.; Joladarashi, S.; Kadoli, R.A twelve-term non-conforming and a sixteen-term conforming displacement polynomial are obtained from Pascal's triangle to deduce the shape functions for a sector element. Using the sector element circular disc is discretized. The number of degrees of freedom for the sector element at a given node is three and four. Kirchhoff's plate theory is the basis for strain energy and kinetic energy because of the transverse motion of the circular plate. Associated stiffness and mass matrices for the sector element are derived in closed form using MATHEMATICA. Using the Lagrange equation, the free vibration equation of motion for the circular disc is derived. A validation study is conducted, and non-dimensional frequencies from the finite element solution are compared with the analytical solutions reported in the literature. Subsequently, the natural frequencies of Al-Al2O3functionally graded circular disc with gradation in the thickness direction are evaluated for a variety of boundary conditions. © 2020 Elsevier Ltd. All rights reserved.Item 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.Item Effect of boundary conditions and convection on thermally induced motion of beams subjected to internal heating(2007) Malik, P.; Kadoli, R.; Ganesan, N.Numerical exercises are presented on the thermally induced motion of internally heated beams under various heat transfer and structural boundary conditions. The dynamic displacement and dynamic thermal moment of the beam are analyzed taking into consideration that the temperature gradient is independent as well as dependent on the beam displacement. The effect of length to thickness ratio of the beam on the thermally induced vibration is also investigated. The type of boundary conditions has its influence on the magnitude of dynamic displacement and dynamic thermal moment. A sustained thermally induced motion is observed with progress of time when the temperature gradient being evaluated is dependent on the forced convection generated due to beam motion. A finite element method (FEM) is used to solve the structural equation of motion as well as the heat transfer equation. © Springer-Verlag 2007.Item Static analysis of functionally graded beams using higher order shear deformation theory(2008) Kadoli, R.; Akhtar, K.; Ganesan, N.Displacement field based on higher order shear deformation theory is implemented to study the static behavior of functionally graded metal-ceramic (FGM) beams under ambient temperature. FGM beams with variation of volume fraction of metal or ceramic based on power law exponent are considered. Using the principle of stationary potential energy, the finite element form of static equilibrium equation for FGM beam is presented. Two stiffness matrices are thus derived so that one among them will reflect the influence of rotation of the normal and the other shear rotation. Numerical results on the transverse deflection, axial and shear stresses in a moderately thick FGM beam under uniform distributed load for clamped-clamped and simply supported boundary conditions are discussed in depth. The effect of power law exponent for various combination of metal-ceramic FGM beam on the deflection and stresses are also commented. The studies reveal that, depending on whether the loading is on the ceramic rich face or metal rich face of the beam, the static deflection and the static stresses in the beam do not remain the same. © 2007 Elsevier Inc. All rights reserved.Item Comparative analysis of steady state heat transfer in a TBC and functionally graded air cooled gas turbine blade(2010) Coomar, N.; Kadoli, R.Internal cooling passages and thermal barrier coatings (TBCs) are presently used to control metal temperatures in gas turbine blades. Functionally graded materials (FGMs), which are typically mixtures of ceramic and metal, have been proposed for use in turbine blades because they possess smooth property gradients thereby rendering them more durable under thermal loads. In the present work, a functionally graded model of an air-cooled turbine blade with airfoil geometry conforming to the NACA0012 is developed which is then used in a finite element algorithm to obtain a non-linear steady state solution to the heat equation for the blade under convection and radiation boundary conditions. The effects of external gas temperature, coolant temperature, surface emissivity changes and different average ceramic/metal content of the blade on the temperature distributions are examined. Simulations are also carried out to compare cooling effectiveness of functionally graded blades with that of blades having TBC. The results highlight the effect of including radiation in the simulation and also indicate that external gas temperature influences the blade heat transfer more strongly. It is also seen that graded blades with about 70% ceramic content can deliver better cooling effectiveness than conventional blades with TBC. © 2010 Indian Academy of Sciences.Item Finite element magnetostatic analysis of magnetostrictive (Tb 0.3Dy0.7Fe1.95) actuator with different housing materials(Defense Scientific Information and Documentation Centre, 2013) Joshi, R.; Subba Rao, M.; Kadoli, R.Permeability of a housing material is one of the significant factors affecting the performance of Tb0.3Dy0.7Fe1.95 based magnetostrictive actuator. According to Lenz's law the rate of flux transfer depends on permeability of housing material surrounding the terfenol-D. In this paper the co-axial coils in a free air are analysed under direct current excitation and the results are found to agree well with both analytical and Maxwell simulation. Also, the comparison of flux density distribution in co-axial coils placed inside different housing materials of magnetostrictive actuator is found by solving magnetostatic equations using Ansoft Maxwell 2D solver. The axial distribution of magnetic flux density, radial distribution of magnetic flux density and flux distribution in the actuator assembly with different housing materials namely mild steel, cast iron and aluminium with and without Terfenol-D are discussed. © 2013, DESIDOC.Item Thermal induced motion of functionally graded beams subjected to surface heating(Ain Shams University, 2018) Malik, P.; Kadoli, R.Thin beam of the functionally graded (FG) type subjected to a step heat input on one surface and insulated or exposed to convective heat loss on the opposite surface is under consideration for the evaluation of thermal induced motion. The dynamic displacement and dynamic thermal moment of the beam are analysed when the temperature gradient is independent of the beam displacement. The power law index dictates the metal–ceramic distribution across thickness of the beam and its effect on the thermal vibration of the beam is examined. The article discusses, in depth, the influence of various factors such as length to thickness ratio of beam, heat transfer boundary conditions, physical boundary conditions, and metal–ceramic combination on the thermal oscillations of FG beam. It is found that attenuation of the amplitude of static thermal deflection and superimposed thermal oscillations is a strong function of the metal–ceramic combination for the FG beam. © 2015 Faculty of Engineering, Ain Shams UniversityItem Nonlinear bending and free vibration response of SUS316-Al2O3 functionally graded plasma sprayed beams: theoretical and experimental study(SAGE Publications Inc. claims@sagepub.com, 2018) Malik, P.; Kadoli, R.Functionally graded SUS316-Al2O3 beams with ceramic content varying from 0 to 40% were prepared by a plasma spraying technique. Nonlinear finite element analysis was used to obtain the static deflection and free vibration of a clamped-free functionally graded beam. Von Kármán geometric nonlinearity and power law variation in material gradation through the beam thickness are considered in the analysis. The maximum error between the experimental and nonlinear finite element results for deflection is 6.68% and 14.31% on the fundamental frequency. Numerical results have also been attempted using ANSYS 3D solid element and they compare more closely with the experimental results. © 2016, © The Author(s) 2016.Item Bending and vibration studies of FG porous sandwich beam with viscoelastic boundary conditions: FE approach(Taylor and Francis Ltd., 2023) Patil, R.; Joladarashi, S.; Kadoli, R.Bending and vibration characteristics of FG porous sandwich beam with viscoelastic boundary conditions are investigated. Complex shear modulus and associated loss factor are considered for the viscoelastic interlayer. The beam is constrained by viscoelastic supports (VES) at either end. Complex stiffness model is adopted for VES. The transverse deflection, natural frequency, loss factors, and mode shapes are obtained by varying VES stiffness. Furthermore, the study is extended to sandwich beams with various (H, O, V, and X) porosity patterns. The results convey that VES contribution in vibration damping is more predominant when the supports are less stiff (more viscous). © 2022 Taylor & Francis Group, LLC.