scholarly journals Analysis of Smart Piezo-Magneto-Thermo-Elastic Composite and Reinforced Plates: Part I – Model Development

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
D. A. Hadjiloizi ◽  
A.L. Kalamkarov ◽  
Ch. Metti ◽  
A. V. Georgiades
Keyword(s):  
Effective Properties ◽  
Practical Importance ◽  
Electric Displacement ◽  
Micromechanical Model ◽  
Composite Plates ◽  
Thin Elastic Plate ◽  
Smart Composite ◽  
Uniform Thickness ◽  
Asymptotic Homogenization ◽  
Static Approximation

AbstractA comprehensive micromechanical model for the analysis of a smart composite piezo-magneto-thermoelastic thin plate with rapidly-varying thickness is developed in the present paper. A rigorous three-dimensional formulation is used as the basis of multiscale asymptotic homogenization. The asymptotic homogenization model is developed using static equilibrium equations and the quasi-static approximation of Maxwell’s equations. The work culminates in the derivation of a set of differential equations and associated boundary conditions. These systems of equations are called unit cell problems and their solution yields such coefficients as the effective elastic, piezoelectric, piezomagnetic, dielectric permittivity and others. Among these coefficients, the so-called product coefficients are also determined which are present in the behavior of the macroscopic composite as a result of the interactions and strain transfer between the various phases but can be absent from the constitutive behavior of some individual phases of the composite material. The model is comprehensive enough to allow calculation of such local fields as mechanical stress, electric displacement and magnetic induction. In part II of this work, the theory is illustrated by means of examples pertaining to thin laminated magnetoelectric plates of uniform thickness and wafer-type smart composite plates with piezoelectric and piezomagnetic constituents. The practical importance of the model lies in the fact that it can be successfully employed to tailor the effective properties of a smart composite plate to the requirements of a particular engineering application by changing certain geometric or material parameters. The results of the model constitute an important refinement over previously established work. Finally, it is shown that in the limiting case of a thin elastic plate of uniform thickness the derived model converges to the familiar classical plate model.

scholarly journals Analysis of Smart Piezo-Magneto-Thermo-Elastic Composite and Reinforced Plates: Part II – Applications

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
D. A. Hadjiloizi ◽  
A.L. Kalamkarov ◽  
Ch. Metti ◽  
A. V. Georgiades
Keyword(s):  
Effective Properties ◽  
Electric Displacement ◽  
Micromechanical Model ◽  
Composite Plates ◽  
Local Fields ◽  
Orthotropic Materials ◽  
Constant Thickness ◽  
Equilibrium Equations ◽  
Static Approximation ◽  
Effective Coefficients

AbstractA comprehensive micromechanical model for the analysis of a smart composite piezo-magneto-thermoelastic thin plate with rapidly varying thickness is developed in Part I of thiswork. The asymptotichomogenization model is developed using static equilibrium equations and the quasi-static approximation of Maxwell’s equations. The work culminates in the derivation of general expressions for effective elastic, piezoelectric, piezomagnetic, dielectric permittivity and other coefficients. Among these coefficients, the so-called product coefficients are determined which are present in the behavior of the macroscopic composite as a result of the interactions between the various phases but can be absent from the constitutive behavior of some individual phases of the composite structure. The model is comprehensive enough to also allow for calculation of the local fields of mechanical stresses, electric displacement and magnetic induction. The present paper determines the effective properties of constant thickness laminates comprised of monoclinic materials or orthotropic materials which are rotated with respect to their principal material coordinate system. A further example illustrates the determination of the effective properties of wafer-type magnetoelectric composite plates reinforced with smart ribs or stiffeners oriented along the tangential directions of the plate. For generality, it is assumed that the ribs and the base plate are made of different orthotropic materials. It is shown in this work that for the purely elastic case the results of the derived model converge exactly to previously established models. However, in the more general case where some or all of the phases exhibit piezoelectric and/or piezomagnetic behavior, the expressions for the derived effective coefficients are shown to be dependent on not only the elastic properties but also on the piezoelectric and piezomagnetic parameters of the constituent materials. Thus, the results presented here represent a significant refinement of previously obtained results.

Fully coupled thermo-magneto-electro-elastic properties of unidirectional smart composites with a piezoelectric interphase

2018 ◽  
Vol 233 (8) ◽  
pp. 2813-2829 ◽  
Author(s):  
M Haghgoo ◽  
R Ansari ◽  
MK Hassanzadeh-Aghdam ◽  
A Darvizeh
Keyword(s):  
Elastic Properties ◽  
Effective Properties ◽  
Constitutive Relations ◽  
Micromechanical Model ◽  
Matrix Composites ◽  
Smart Composite ◽  
Fiber Volume ◽  
Two Phase ◽  
Smart Composites ◽  
Fully Coupled

In the present study, the effect of PZT-5A piezoelectric interphase on the effective thermo-magneto-electro-elastic properties of CoFe2O4 piezomagnetic matrix composites reinforced with carbon fibers is investigated. In this type of three-phase smart composite, the unidirectional fiber is coated with the piezoelectric shell. To this end, the fully coupled thermo-magneto-electro-elastic constitutive relations are developed for a unit cell-based micromechanical model in conjunction with a proper representative volume element. The influences of piezoelectric interphase thickness on the effective properties of the unidirectional smart composite are extensively investigated at different carbon fiber volume fractions up to 70%. The results demonstrate that piezoelectric interphase can greatly affect the overall thermo-magneto-electro-elastic properties of the smart composites. For two-phase smart composites, the present predictions are found to be in close proximity with the Mori–Tanaka results, which validates the present model.

Analytical and Numerical Predictions of Thermoelastic Properties of Carbon Single-Walled Nanotubes

Aerospace ◽  
2005 ◽  
Author(s):  
Vinod P. Veedu ◽  
Davood Askari ◽  
Mehrdad N. Ghasemi-Nejhad
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Graphene Sheet ◽  
Effective Properties ◽  
Constitutive Models ◽  
Thermoelastic Properties ◽  
Asymptotic Homogenization ◽  
Element Analysis ◽  
Single Walled Nanotubes ◽  
Numerical Predictions

The objective of this paper is to develop constitutive models to predict thermoelastic properties of carbon single-walled nanotubes using analytical, asymptotic homogenization, and numerical, finite element analysis, methods. In our approach, the graphene sheet is considered as a non-homogeneous network shell layer which has zero material properties in the regions of perforation and whose effective properties are estimated from the solution of the appropriate local problems set on the unit cell of the layer. Our goal is to derive working formulas for the entire complex of the thermoelastic properties of the periodic network. The effective thermoelastic properties of carbon nanotubes were predicted using asymptotic homogenization method. Moreover, in order to verify the results of analytical predictions, a detailed finite element analysis is followed to investigate the thermoelastic response of the unit cells and the entire graphene sheet network.

Hygrothermal Buckling Response of Laminated Composite Plates with Random Material Properties: Micro-Mechanical Model

2011 ◽  
Vol 110-116 ◽  
pp. 113-119 ◽  
Author(s):  
Rajesh Kumar ◽  
Dharamveer Singh
Keyword(s):  
Material Properties ◽  
Plate Theory ◽  
Perturbation Technique ◽  
Micromechanical Model ◽  
Laminated Composite ◽  
Composite Plates ◽  
Second Order Statistics ◽  
Operational Life ◽  
Safety And Reliability ◽  
Random Material Properties

The aim of this paper is to find out the randomness in the material properties on the buckling of laminated composite plate needed for the economy, safety and reliability of the structures and components in their operational life especially for sensitive Aerospace Engineering applications in hygrothermal environments. Micromechanical model has been taken for the analysis .The used methodology is a C0 finite element method based on higher-order shear deformation plate theory for deriving the standard eigenvalue problem. A Taylor series based mean-centered first order perturbation technique is used to find out the second order statistics of the hygrothermal buckling loads under different sets of environmental conditions..The numerical results for deterministic parameters are compared and validated with available literature and random parameters with independent Monte Carlo Simulation. The result shows that the plate is significantly affected by the hygrothermal buckling load.

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