Institute Superieur Of Mecanique Of Paris

Saint-Ouen-l'Aumône, France

Institute Superieur Of Mecanique Of Paris

Saint-Ouen-l'Aumône, France
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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
Advances in Aircraft and Spacecraft Science | Year: 2015

Theoretical and numerical assessments of approximate evaluations and simplified analyses of piezoelectric structures transverse shear modal effective electromechanical coupling coefficient (EMCC) are presented. Therefore, the latter is first introduced theoretically and its approximate evaluations are reviewed; then, three-dimensional (3D) and simplified two-dimensional (2D) plane-strain (PStrain) and plane-stress (PStress) piezoelectric constitutive behaviors of electroded shear piezoceramic patches are derived and corresponding expected short-circuit (SC) and open-circuit (OC) frequencies and resulting EMCC are discussed; next, using a piezoceramic shear sandwich beam cantilever typical benchmark, a 3D finite element (FE) assessment of different evaluation techniques of the shear modal effective EMCC is conducted, including the equipotential (EP) constraints effect; finally, 2D PStrain and PStress FE modal analyses under SC and OC electric conditions, are conducted and corresponding results (SC/OC frequencies and resulting effective EMCC) are compared to 3D ones. It is found that: (i) physical EP constraints reduce drastically the shear modal effective EMCC; (ii) PStress and PStrain results depend strongly on the filling foam stiffness, rendering inadequate the use of popular equivalent single layer models for the transverse shear-mode sandwich configuration; (iii) in contrary to results of piezoelectric shunted damping and energy harvesting popular single-degree-of-freedom-based models, transverse shear modal effective EMCC values are very small in particular for the first mode which is the common target of these applications. © 2015 Techno-Press, Ltd.

Agency: European Commission | Branch: FP7 | Program: CP | Phase: SPA-2007-2.2-02 | Award Amount: 6.56M | Year: 2009

In Space Propulsion 1 was set up to improve the fundamental knowledge and the techniques which are necessary to allow Europe to implement new ambitious space programs involving cryogenic propulsion. It concentrates on liquid oxygen, liquid hydrogen, and liquid methane propellants, and the anticipated progress will address - LOX methane combustion - heat and propellant management - materials tribology, compatibility, and hydrogen embrittlement.

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.

Trindade M.A.,University of Sao Paulo | Benjeddou A.,Institute Superieur Of Mecanique Of Paris
Acta Mechanica | Year: 2013

Nonlinear dependence between mechanical deformation and applied voltage has been experimentally observed on a recently manufactured lengthwise poled piezoelectric d 15 shear macro-fibre composite (MFC) transducer. This work proposes a methodology to model this phenomenon by combining the nonlinear behaviour of the constituent piezoceramic fibre (electric field dependence of material properties) with a finite element homogenization technique to evaluate the resulting nonlinearity of the effective properties of the d 15 MFC. Results show that the experimentally observed nonlinear behaviour of d 15 MFC is reasonably well predicted by the proposed methodology indicating that this behaviour could be explained by an electric field dependence of the piezoceramic fibre material properties. Results also show that d 15 and Ïμ 11 T coefficients of the d 15 MFC are not significantly reduced by the MFC packaging, while e 15 and G 13 coefficients are reduced by 90 %, compared to the piezoceramic fibre ones. A conducted parametric analysis indicates that the actuation performance of the d 15 MFC transducer could be improved by increasing the active layer thickness. © 2013 Springer-Verlag Wien.

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.

Renaud F.,Institute Superieur Of Mecanique Of Paris | Dion J.-L.,Institute Superieur Of Mecanique Of Paris | Chevallier G.,Institute Superieur Of Mecanique Of Paris | Tawfiq I.,Institute Superieur Of Mecanique Of Paris | Lemaire R.,Robert Bosch GmbH
Mechanical Systems and Signal Processing | Year: 2011

This paper focuses on the generalized Maxwell model (GMM) identification. The formulation of the transfer function of the GMM is defined, as well as its asymptotes. To compare identification methods of the parameters of the GMM, a test transfer function and two quality indicators are defined. Then, three graphical methods are described, the enclosing curve method, the CRONE method and an original one. But the results of graphical methods are not good enough. Thus, two optimization recursive processes are described to improve the results of graphical methods. The first one is based on an unconstrained non-linear optimization algorithm and the second one is original and allows constraining identified parameters. This new process uses the asymptotes of the modulus and the phase of the transfer function of the GMM. The result of the graphical method optimized with the new process is very accurate and fast. © 2010 Elsevier Ltd.All rights reserved.

This contribution presents numerical and experimental assessments of the modal effective electromechanical coupling coefficient (EMCC) using popular approximate evaluations and simplified analyses of piezoelectric structures. For this purpose, first, a common benchmark, consisting of a cantilever Aluminum (Al) beam with symmetrically surface-bonded two pairs of large piezoceramic (PZT) patches, is retained for the assessment of EMCC different evaluation formulas and plane strain (PStrain) and plane stress (PStress) two-dimensional (2D) analyses using ANSYS coupled piezoelectric three-dimensional (3D) and 2D finite elements (FE). Then, similarly, an experimental assessment is conducted on two benchmarks consisting of Al long and short cantilevers equipped symmetrically with pairs of small and large PZT patches. It is found that, in order to get EMCC accurate approximate numerical evaluation, it is crucial to consider the patches electrodes equipotential constraints and, in order to get EMCC accurate 2D results with regard to 3D calculations, it is necessary to use PStress kinematics for approximate 2D analysis. Besides, 3D FE and experimental frequencies are shown to be bounded from below by PStress and from above by PStrain 2D FE results. Moreover, EMCC 2D PStress results are found closer to 3D FE and experimental results than PStrain 2D FE ones. © 2014, Springer-Verlag Wien.

Casimir J.B.,Institute Superieur Of Mecanique Of Paris | Vinh T.,Institute Superieur Of Mecanique Of Paris
Journal of Sound and Vibration | Year: 2012

A interesting double pendulum system permits evaluating complex moduli (Young and shear) without independent excitation and transducers. This instrument was described at France in 1934 by Le Rolland and Sorin in Etude dune méthode utilisant le couplage entre deux systèmes oscillants pour la détermination de la résistance mécanique des constructions et la mesure des modules délasticité, scientific and technical publications of the Air Force Ministry, no. 47, 1934. This device is revisited and improved in order to make it applicable to measurements of viscoelastic materials. © 2011 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.

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