Diapositive 1

Adaptive shunted piezoelectric metacomposite: a new integrated technology for vibroacoustic controlDr M. Collet(1), Dr M. Ouisse(1), F. Tato, Pr M. Ichchou(2), T. Huang(2)

Dept Applied MechanicsFEMTO-ST UMR 6174, Besanon, France (2) LTDS, Ecole Centrale de Lyon, Ecully, France

dMEMS Conf, Besanon 2012universit de technologieBelfort-MontbliarddMEMS 2012 - BesanonMotivations2Classical approaches of ANC or AVC is difficult to apply into real fully distributed applications : Technological and Numerical complexity Difficulties for integrating such technology into the Design Process (Robustness/Performances) Energy CostNecessity to propose a new approach .

Active Control of Vibroacoustic interface by the synthesis of generalized Impedance operatoruniversit de technologieBelfort-MontbliarddMEMS 2012 - Besanon3To Program the behavior relationship inside hybrid composite material by using a distributed set of smart cells including transducers, Computing capabilities and smart materials .

We have to Synthetize and integrate dedicated programmable vibroacoustic functionnalities inside structures for realizing adaptive interfaces.

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Motivationsuniversit de technologieBelfort-MontbliarddMEMS 2012 - Besanon4The Targeted ApplicationLet us consider the elasto-dynamical wave control by means of shunted piezoelectric periodic patches :

The shunt impedance is complexDamped SystemWe obtain evanescent Bloch wave and damped scattering

By using WFE techniques => Optimization of the energy diffusion* for wave trap

* M. Collet, K.A. Cunefare, N.M. Ichchou, Wave Motion Optimization in Periodically Distributed Shunted Piezocomposite Beam Structures Journal of Intelligent Material Systems and Structures, 20(7), 787-808, 2009universit de technologieBelfort-MontbliarddMEMS 2012 - Besanon6

Part 1-Mathematical FormulationdMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard7Bloch Expansion Theorem

Generic Elliptic PDE :

(Bloch Expansion)

where are the eigenvectors :

of the shifted cell operator :Periodic SystemdMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard10

Part 2-Electric Impedance OptimizationdMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard

11The Considered SystemPZT-Aluminum Composite

dMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard12Optimization of the shunted electric impedance The Critera for Optimizing the Flexural Wave Propagation:Based on computing the Group Velocity :

Two vibroacoustic functions to minimize is (Nelder Mead algorithm): (Transmission)

(Absorption)

The normal acoustic wave number is given by :

dMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard13Transmission OptimizationInduced effects on Acoustic normal wave number

Acoustic coincidencedMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard5Challenges and ContentsFields of interestWave propagation in multiphysics and periodic systems : Smart Wave GuidesStructural Health Monitoring (Faults detection)Noise & Vibration Reduction in Complex Structures (Optimization of passive or active systems)Available TechniquesFloquet theorem in 1D waveguide (SAFE, WFE, TL techniques )Bloch theorem in 2D for undamped or weakly damped systems (WFE)ChallengesTo predict and analyze complex waves vectors of damped mechanical systems with multiphysics coupling introduced by shunted piezoelectric patchesApproachFormulate Bloch Expansion theorem for damped piezo-elastodynamic problemsIntroduce a suitable criterion based on Waves Intensity vectorContents - OutlineMathematical methodologyOptimization of the shunted electric impedance Acoustic induced control and 3D validations.

universit de technologieBelfort-MontbliarddMEMS 2012 - Besanon

15Effect on Acoustic normal wave number

Acoustic coincidenceAcoustic decay rateAbsorption OptimizationdMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard

16Dissipative CircuitQuasi constant Cneg :The Optimal Impedance

Absorption OptimizationdMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard17Validation on a periodically semi-distributed adaptive cellsThe considered System :

dMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard18Validation on a periodically semi-distributed adaptive cells

dMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard19ConclusionsWave Dispersion in 2DApplication of the Bloch TheoremShunted Piezoelectric SystemFinite Element Approach (Multiphics)ConceptsWhole 2D K-space computation with electric shuntGroup Velocity based IndicatorImpedance optimizationVibroacoustic energy diffusion controlResultsPeriodic smart StructuresPassive, semi-active or active controlWaves Diffusion at 2D Medium InterfaceWave Trap ConceptsFuture

dMEMS 2012, Besanonuniversit de technologieBelfort-Montbliard