Coupled evaluation of the free vibration characteristics of magneto-electro-elastic skew plates in hygrothermal environment

Vinyas Mahesh,Subhaschandra Kattiman,Dineshkumar Harursampath,Nguyen-Thoi Trung 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.2

The present article addresses the coupled free vibration problem of skew magneto-electro-elastic plates (SMEE) considering the temperature-moisture dependent material properties. The plate kinematics follows Reddy’s higher order shear deformation theory. With the aid of finite element methods, the governing equations of motion are derived considering the Hamilton’s principle and solved by adopting condensation technique. The influence of different temperature and moisture dependent empirical constants on the frequency response of SMEE plate has been assessed. In addition, the natural frequencies corresponding to various fields are evaluated and the effect of empirical constants on these coupled frequencies is determined. A detailed parametric study has been carried out to assess the individual effects of temperature and moisture dependent empirical constants along with their combined effect, aspect ratio, length-to-width ratio, stacking sequence and boundary conditions. The results reveal that the external environment as well as the geometrical skewness has a significant influence on the stiffness of the SMEE plates.

Multiphysics response of magneto-electro-elastic beams in thermo-mechanical environment

Vinyas, M.,Kattimani, S.C. Techno-Press 2017 Coupled systems mechanics Vol.6 No.3

In this article, the multiphysics response of magneto-electro-elastic (MEE) cantilever beam subjected to thermo-mechanical loading is analysed. The equilibrium equations of the system are obtained with the aid of the principle of total potential energy. The constitutive equations of a MEE material accounting the thermal fields are used for analysis. The corresponding finite element (FE) formulation is derived and model of the beam is generated using an eight noded 3D brick element. The 3D FE formulation developed enables the representation of governing equations in all three axes, achieving accurate results. Also, geometric, constitutive and loading assumptions required to dimensionality reduction can be avoided. Numerical evaluation is performed on the basis of the derived formulation and the influence of various mechanical loading profiles and volume fractions on the direct quantities and stresses is evaluated. In addition, an attempt has been made to compare the individual effect of thermal and mechanical loading with the combined effect. It is believed that the numerical results obtained helps in accurate design and development of sensors and actuators.

A 3D finite element static and free vibration analysis of magneto-electro-elastic beam

Vinyas., M,Kattimani, S.C. Techno-Press 2017 Coupled systems mechanics Vol.6 No.4

In this paper, free vibration and static response of magneto-electro-elastic (MEE) beams has been investigated. To this end, a 3D finite element formulation has been derived by minimization the total potential energy and linear constitutive equation. The coupling between elastic, electric and magnetic fields can have a significant influence on the stiffness and in turn on the static behaviour of MEE beam. Further, different Barium Titanate ($BaTiO_3$) and Cobalt Ferric oxide ($CoFe_2O_4$) volume fractions results in indifferent coupled response. Therefore, through the numerical examples the influence of volume fractions and boundary conditions on the natural frequencies of MEE beam is illustrated. The study is extended to evaluate the static response of MEE beam under various forms of mechanical loading. It is seen from the numerical evaluation that the volume fractions, loading and boundary conditions have a significant effect on the structural behaviour of MEE structures. The observations made here may serve as benchmark solutions in the optimum design of MEE structures.

Design modification and structural behavior study of a CFRP star sensor baffle

Vinyas, M.,Vishwas, M.,Venkatesha, C.S.,Rao, G. Srinivasa Techno-Press 2016 Advances in aircraft and spacecraft science Vol.3 No.4

Star sensors are the attitude estimation sensors of the satellite orbiting in its path. It gives information to the control station on the earth about where the satellite is heading towards. It captures the images of a predetermined reference star. By comparing this image with that of the one captured from the earth, exact position of the satellite is determined. In the process of imaging, stray lights are eliminated from reaching the optic lens by the mechanical enclosures of the star sensors called Baffles. Research in space domain in the last few years is mainly focused on increased payload capacity and reduction in launch cost. In this paper, a star sensor baffle made of Aluminium is considered for the study. In order to minimize the component weight, material wastage and to improve the structural performance, an alternate material to Aluminium is investigated. Carbon Fiber Reinforced Polymer is found to be a better substitute in this regard. Design optimisation studies are carried out by adopting suitable design modifications like implementing an additional L-shaped flange, Upward flange projections, downward flange projections etc. A better configuration of the baffle, satisfying the design requirements and achieving manufacturing feasibility is attained. Geometrical modeling of the baffle is done by using UNIGRAPHICS-Nx7.5(R). Structural behavior of the baffle is analysed by FE analysis such as normal mode analysis, linear static analysis, and linear buckling analysis using MSC/PATRAN(R), MSC-NASTRAN(R) as the solver to validate the stiffness, strength and stability requirements respectively. Effect of the layup sequence and the fiber orientation angle of the composite layup on the stiffness are also studied.

Static behavior of thermally loaded multilayered Magneto-Electro-Elastic beam

Vinyas, M.,Kattimani, S.C. Techno-Press 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.4

The present article examines the static response of multilayered magneto-electro-elastic (MEE) beam in thermal environment through finite element (FE) methods. On the basis of the minimum total potential energy principle and the coupled constitutive equations of MEE material, the FE equilibrium equations of cantilever MEE beam is derived. Maxwell's equations are considered to establish the relation between electric field and electric potential; magnetic field and magnetic potential. A simple condensation approach is employed to solve the global FE equilibrium equations. Further, numerical evaluations are made to examine the influence of different in-plane and through-thickness temperature distributions on the multiphysics response of MEE beam. A parametric study is performed to evaluate the effect of stacking sequence and different temperature profiles on the direct and derived quantities of MEE beam. It is believed that the results presented in this article serve as a benchmark for accurate design and analysis of the MEE smart structures in thermal applications.

Thermal response analysis of multi-layered magneto-electro-thermo-elastic plates using higher order shear deformation theory

M. Vinyas,D. Harursampath,S.C. Kattimani 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.6

In this article, the static responses of layered magneto-electro-thermo-elastic (METE) plates in thermal environment have been investigated through FE methods. By using Reddy’s third order shear deformation theory (TSDT) in association with the Hamilton’s principle, the direct and derived quantities of the coupled system have been obtained. The coupled governing equations of METE plates have been derived through condensation technique. Three layered METE plates composed of piezoelectric and piezomagnetic phases are considered for evaluation. For investigating the correctness and accuracy, the results in this article are validated with previous researches. In addition, a special attention has been paid to evaluate the influence of different electro-magnetic boundary conditions and pyrocoupling on the coupled response of METE plates. Finally, the influence of stacking sequences, magnitude of temperature load and aspect ratio on the coupled static response of METE plates are investigated in detail.

A finite element based assessment of static behavior of multiphase magneto-electro-elastic beams under different thermal loading

M. Vinyas,S.C. Kattimani 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.5

In this article, static analysis of a magneto-electro-elastic (MEE) beam subjected to various thermal loading and boundary conditions has been investigated. Influence of pyroeffects (pyroelectric and pyromagnetic) on the direct quantities (displacements and the potentials) of the MEE beam under different boundary conditions is studied. The finite element (FE) formulation of the MEE beam is developed using the total potential energy principle and the constitutive equations of the MEE material taking into account the coupling between elastic, electric, magnetic and thermal properties. Using the Maxwell electrostatic and electromagnetic relations, variation of stresses, displacements, electric and magnetic potentials along the length of the MEE beam are investigated. Effect of volume fractions, aspect ratio and boundary conditions on the direct quantities in thermal environment has been determined. The present investigation may be useful in design and analysis of magnetoelectroelastic smart structures and sensor applications.

Vibration based energy harvesting performance of magneto-electro-elastic beams reinforced with carbon nanotubes

Arjun Siddharth Mangalasseri,Vinyas Mahesh,Sriram Mukunda,Vishwas Mahesh,Sathiskumar A Ponnusami,Dineshkumar Harursampath,Abdelouahed Tounsi Techno-Press 2023 Advances in nano research Vol.14 No.1

This article investigates the energy harvesting characteristics of a magneto-electro-elastic (MEE) cantilever beam reinforced with carbon nanotubes (CNT) under transverse vibration. To this end, the well-known lumped parameter model is used to represent the coupled multiphysics problem mathematically. The proposed system consists of the MEE-CNT layer on top and an inactive substrate layer at the bottom. The substrate is considered to be made of either an isotropic or composite material. Basic laws such as Gauss's Law, Newton's Law and Faraday's Law are used to arrive at the governing equations. Surface electrodes across the beam are used to harvest the electric potential produced, together with a wound coil, for the generated magnetic potential. The influence of various distributions of the CNT and its volume fraction, substrate material, length-to-thickness ratio, and thickness ratio of substrate to MEE layer on the energy harvesting behaviour is thoroughly discussed. Further, the effect of external resistances and changes in substrate material on the response is analysed and reported. The article aims to explore smart material-based energy harvesting systems, focusing on their behaviour when reinforced with carbon nanotubes. The results of this study may lead to an improved understanding of the design and analysis of CNT-based smart structures.

Free Vibration Analysis of Graphene Platelets–Reinforced Composites Plates in Thermal Environment Based on Higher-Order Shear Deformation Plate Theory

Saeedeh Qaderi,Farzad Ebrahimi,Vinyas Mahesh 한국항공우주학회 2019 International Journal of Aeronautical and Space Sc Vol.20 No.4

As a first endeavor, this article presents the free vibration of composite plates reinforced with graphene platelets (GPLs) based on the higher-order shear deformation plate theory. Moreover, it is assumed that the material properties are temperature dependent and are graded in the thickness direction. It is assumed that GPLs randomly spread out in each individual composite layer reinforced with graphene platelets. The theoretical formulation is derived based on higher-order shear deformation plate theory and the initial thermal stresses are evaluated by solving the thermo-elastic equilibrium equations. The Halpin–Tsai micromechanical model is used to evaluate the effective material properties of every layer of composite plates reinforced GPLs. Further, the Navier solution has been used to derive the governing equations of motion and evaluate the natural frequencies and dynamic response of simply supported graphene platelet reinforced composite plates. Four different GPL distribution pattern is modeled to find out its effect on the frequency of the plate and the other parameters. The result asserted that subjoining GPL to composite plates has a significant reinforcing effect on the free vibration of Graphene platelet reinforced composite (GPLRC) plates.

Assessment of porosity influence on dynamic characteristics of smart heterogeneous magneto-electro-elastic plates

Farzad Ebrahimi,Ali Jafari,Vinyas Mahesh 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.1

A four-variable shear deformation refined plate theory has been proposed for dynamic characteristics of smart plates made of porous magneto-electro-elastic functionally graded (MEE-FG) materials with various boundary conditions by using an analytical method. Magneto-electro-elastic properties of FGM plate are supposed to vary through the thickness direction and are estimated through the modified power-law rule in which the porosities with even and uneven type are approximated. Pores possibly occur inside functionally graded materials (FGMs) due the result of technical problems that lead to creation of micro-voids in these materials. The variation of pores along the thickness direction influences the mechanical properties. The governing differential equations and boundary conditions of embedded porous FGM plate under magneto-electrical field are derived through Hamilton\'s principle based on a four-variable tangential-exponential refined theory which avoids the use of shear correction factors. An analytical solution procedure is used to achieve the natural frequencies of embedded porous FG plate supposed to magneto-electrical field with various boundary condition. A parametric study is led to carry out the effects of material graduation exponent, coefficient of porosity, magnetic potential, electric voltage, elastic foundation parameters, various boundary conditions and plate side-to-thickness ratio on natural frequencies of the porous MEE-FG plate. It is concluded that these parameters play significant roles on the dynamic behavior of porous MEE-FG plates. Presented numerical results can serve as benchmarks for future analyses of MEE-FG plates with porosity phases.