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Saint-Ouen-l'Aumône, France

Trindade M.A.,University of Sao Paulo | Benjeddou A.,Institute Superieur Of Mecanique Of Paris
Smart Materials and Structures | Year: 2011

A finite element homogenization method for a shear actuated d15 macro-fibre composite (MFC) made of seven layers (Kapton, acrylic, electrode, piezoceramic fibre and epoxy composite, electrode, acrylic, Kapton) is proposed and used for the characterization of its effective material properties. The methodology is first validated for the MFC active layer only, made of piezoceramic fibre and epoxy, through comparison with previously published analytical results. Then, the methodology is applied to the seven-layer MFC. It is shown that the packaging reduces significantly the shear stiffness of the piezoceramic material and, thus, leads to significantly smaller effective electromechanical coupling coefficient k15 and piezoelectric stress constant e15 when compared to the piezoceramic fibre properties. However, it is found that the piezoelectric charge constant d15 is less affected by the softer layers required by the MFC packaging. © 2011 IOP Publishing Ltd.

Kranz B.,Fraunhofer Institute for Machine Tools and Forming Technology | Benjeddou A.,Institute Superieur Of Mecanique Of Paris | Drossel W.-G.,TU Chemnitz
Acta Mechanica | Year: 2013

This contribution presents original numerical and experimental characterizations for prototyped longitudinally polarized piezoelectric d 15 shear macro-fiber composites (MFC). The numerical characterization consists of a finite element (FE) simulation based on a representative volume element. It implements an enthalpy-based homogenization method (EBHM), recently proposed by the authors, as an extension of the so-called strain energy method to orthotropic piezoelectric fiber-reinforced composites. The numerical validation is carried out on a previously assumed layout of shear MFC. Later on, the EBHM is used to get the effective electromechanical material parameters of the shear MFC actual layout. These parameters are further validated experimentally through their use in the FE simulation of an original actuation benchmark that is proposed for the manufactured shear MFC experimental characterization. The latter is based on low-frequency (quasi-static) displacement measurements where the shear MFC serves as a voltage-driven actuator. Due to the small overall dislocation, a laser vibrometer is used for the measurements. The comparison of experimental and numerical results shows a reasonably good agreement and a nonlinear actuation response is observed. This work's major outcomes are the experimental validation of the EBHM and the actuation functional operability of the manufactured longitudinally polarized piezoelectric d 15 shear MFC. This opens the possibility for their application as actuator and sensor of shear-induced bending and torsion for vibration, shape and health control, or as a transducer for energy harvesting. © 2013 Springer-Verlag Wien.

Tounsi D.,University of Sfax | Casimir J.B.,Institute Superieur Of Mecanique Of Paris | Haddar M.,University of Sfax
Computers and Structures | Year: 2012

This paper describes a procedure for calculating the dynamic stiffness matrix of a circular ring. The basis of the dynamic stiffness method resides in determining the dynamic stiffness matrix of such structural elements. The solution of the elementary problem is derived using Hamilton's principle and a Fourier series expansion of the solution. Concentrated and distributed loads are applied to the ring along several directions in order to determine the response of the system. The performances of the method are evaluated using comparisons with the harmonic responses of a circular ring obtained using the finite element method. © 2012 Elsevier Ltd. All rights reserved.

Benjeddou A.,Institute Superieur Of Mecanique Of Paris | Hamdi M.,Institute Superieur Des Science Appliquees Et Of Technology
Composite Structures | Year: 2016

The effective three-dimensional elastic behaviour of a rectangular piezoceramic patch centrally surface-bonded to a free multilayer unidirectional carbon-fibre reinforced plastic composite plate is inversely identified from three potential ones: orthotropic, quasi transversely isotropic (QTI) or transversely isotropic. This is reached through minimizing the finite element-experimental frequency relative deviations of the first eight short-circuit modes of the smart composite structure using a robust multi-objective evolutionary optimization procedure. The latter combines full factorial design of experiments (DoE)-based surface response meta-modelling of the frequency dependence on the patch's elastic engineering constants and a non-sorting genetic algorithm of second generation. The inverse identification robustness comes from considering large uncertainties (±20%) of the design parameters nominal (initial) values. DoE-based sensitivities of the considered frequencies to the investigated piezoceramic patch's elastic behaviour engineering constants are analyzed in order to identify the most influent design parameters. The latter are used for reducing the DoE plans and corresponding finite element computations. It is found that the bonded patch's effective elastic behaviour is QTI (or orthotropic) when all (or the most influent) engineering constants are optimized. © 2016 Elsevier Ltd.

Zouari W.,University of Lorraine | Ben Zineb T.,University of Lorraine | Benjeddou A.,Institute Superieur Of Mecanique Of Paris
International Journal of Solids and Structures | Year: 2011

An isoparametric 3D electromechanical hexahedral finite element integrating a 3D phenomenological ferroelectric and ferroelastic constitutive law for domain switching effects is proposed. The model presents two internal variables which are the ferroelectric polarization (related to the electric field) and the ferroelastic strain (related to the mechanical stress). An implicit integration technique of the constitutive equations based on the return-mapping algorithm is developed. The mechanical strain tensor and the electric field vector are expressed in a curvilinear coordinate system in order to handle the transverse isotropy behavior of ferroelectric ceramics. The hexahedral finite element is implemented into the commercial finite element code Abaqus® via the subroutine user element. Some linear (piezoelectric) and non linear (ferroelectric and ferroelastic) benchmarks are considered as validation tests. © 2010 Elsevier Ltd. All rights reserved.

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