The method partial weakening operation evolves cognitive function by the children in all areas cognition: optical and acoustic sensation, cubic orientation, connecting of sensation especially optical and acoustical (intermodalita), gradual thinking from simplest to more complicated (serialita), also evolve motorial abilities, speech and communication. At the same time also evolve social relations, moral-ethic principles and administer to general evolvement children{\crq}s personality in preschool and younger school age. The graduation these is structured to chapters. The first to third chapter i. a. treats of history of method, aetiology, clinical symptoms, appearance, diagnostics and retrieval partial weakening operation. In the fourth chapter are analysed psychological characteristics preschool children. The fifth chapter reflects testing of optical disabled and auditory disabled children. The sixth chapter reflects the ethic dilemma work with children. The final chapter reflects expertly treated cases.

L’identification et la caractérisation des sources acoustiques restent encore aujourd’hui deux sujets d’importance pour les industriels qui ont besoin de techniques permettant d’identifier des sources acoustiques ou vibratoires sur des surfaces complexes dans un environnement acoustique non contrôlé. La thèse que nous présentons ici s'inscrit dans ce cadre. Nous y étudions les qualités d'une méthode inverse, appelée iPTF (pour inverse Patch Transfer Functions, pour la résolution de ce problème particulier. Nous consacrerons le premier chapitre de notre étude à la synthèse bibliographique des méthodes les plus pertinentes permettant de résoudre des problèmes similaires. Nous soulignerons également les difficultés de ces méthodes pouvant être liées à leurs applications pratiques ou à leurs fondements théoriques. Dans un second chapitre, nous présenterons la méthode iPTF à partir de sa formulation directe, c'est-à-dire de la source vers le bruit rayonné. Celle-ci est une approche par sous-structuration de domaines permettant l’étude des problèmes vibro-acoustiques en basses et moyennes fréquences. Nous montrerons particulièrement la façon dont l'association des deux formulations directe et indirecte permet de définir une méthode pouvant conduire jusqu'à l'identification des trois champs de vitesses, de pressions et d'intensités sur la surface de l'objet source. Notre troisième chapitre sera consacré à la présentation des premiers résultats d'identification dans un cas d'application numérique simple. Nous effectuerons, dans les chapitres quatre et cinq, une étude des principaux paramètres conditionnant les résultats donnés par la méthode. Le premier de ces deux chapitres présentera la mise en place d'un code de calcul permettant de résoudre rapidement le problème de rayonnement d'une structure simple. La méthode ainsi définie sera utilisée dans le chapitre cinq afin de générer de nombreux champs rayonnés présentant des caractéristiques différentes de façon à étudier la stabilité de la méthode iPTF face à la variation de différents paramètres. Un sixième chapitre présentera une étude approfondie faite sur les ondes évanescentes qui prennent une part non négligeable dans le champ rayonné par les structures. Ces ondes évanescentes, par définition, ne peuvent pas être mesurées au delà du champ proche, ce qui peut être la cause d'une part des défauts d'identification rencontrés lors de l'application de notre méthode. L'étude faite ici aura pour but de déterminer l'importance de ces ondes évanescentes dans le champ rayonné. Nous présenterons enfin, dans un dernier chapitre, les résultats de mesures expérimentales réalisées. / Nowadays, both identification and characterization of acoustical sources remain two important topics in industry as such method are often required to localize acoustical or vibrational sources on complex surfaces in an acoustical environment that may not be well-known. The PhD Thesis we present hereby is set in this purpose. We will study the ability of an inverse method, named iPTF (standing for inverse Patch Transfert Functions) used to solve this particular problem. In our first chapter we will present a bibliographical study of the different methods dealing with the resolution of similar problems. We will particularly underline the difficulties encountered with these methods, either regarding their practical application or their theoretical bases. The presentation of the iPTF method will be made in the second chapter. This presentation will be organized starting from the direct formulation, that is from the source to the radiated sound. This direct method is a sub-domai decomposition based approach, allowing the study of vibro-acoustical problems in low and mid frequencies. We will especially explain how the association of both direct and reverse formulation enables to identify the pressure, velocity and intensity fields on the source. The third chapter will concerne the presentation of the first identification results in a simple numerical application. In the fourth and fifth chapters, the main parameters conditioning the results given by our method will be studied. The first of these two chapters will introduce a calculation routine used to compute quickly the radiation field of a simple structure. This routine will then be used in our fifth chapter in order to build numerous fields having different characteristics. Using all these fields will let us know the stability of our method regarding different parameters. A sixth chapter will present a precise study of evanescent waves that constitute a non-neglectful part of the radiated field. According to their definition, those evanescent waves cannot be taken into account beyond the near-field, and this may be the reason of some difficulties while applying our method. The objective of the study herein presented is to determine the importance of those evanescent waves in the radiated field. We eventually present, in a last chapter, the results of experimental measures conducted during the preparation of this PhD Thesis.

La caractérisation expérimentale de sources acoustiques est l'une des étapes essentielles pour la réduction des nuisances sonores produites par les machines industrielles. L'objectif de la thèse est de mettre au point une procédure complète visant à localiser et à quantifier des sources acoustiques stationnaires ou non sur un maillage surfacique par la rétro-propagation d'un champ de pression mesuré par un réseau de microphones. Ce problème inverse est délicat à résoudre puisqu'il est généralement mal-conditionné et sujet à de nombreuses sources d'erreurs. Dans ce contexte, il est capital de s'appuyer sur une description réaliste du modèle de propagation acoustique direct. Dans le domaine fréquentiel, la méthode des sources équivalentes a été adaptée au problème de l'imagerie acoustique dans le but d'estimer les fonctions de transfert entre les sources et l'antenne, en prenant en compte le phénomène de diffraction des ondes autour de l'objet d'intérêt. Dans le domaine temporel, la propagation est modélisée comme un produit de convolution entre la source et une réponse impulsionnelle décrite dans le domaine temps-nombre d'onde. Le caractère sous-déterminé du problème acoustique inverse implique d'utiliser toutes les connaissances a priori disponibles sur le champ sources. Il a donc semblé pertinent d'employer une approche bayésienne pour résoudre ce problème. Des informations a priori disponibles sur les sources acoustiques ont été mises en équation et il a été montré que la prise en compte de leur parcimonie spatiale ou de leur rayonnement omnidirectionnel pouvait améliorer significativement les résultats. Dans les hypothèses formulées, la solution du problème inverse s'écrit sous la forme régularisée de Tikhonov. Le paramètre de régularisation a été estimé par une approche bayésienne empirique. Sa supériorité par rapport aux méthodes communément utilisées dans la littérature a été démontrée au travers d'études numériques et expérimentales. En présence de fortes variabilités du rapport signal à bruit au cours du temps, il a été montré qu'il est nécessaire de mettre à jour sa valeur afin d'obtenir une solution satisfaisante. Finalement, l'introduction d'une variable manquante au problème reflétant la méconnaissance partielle du modèle de propagation a permis, sous certaines conditions, d'améliorer l'estimation de l'amplitude complexe des sources en présence d'erreurs de modèle. Les développements proposés ont permis de caractériser, in situ, la puissance acoustique rayonnée par composant d'un groupe motopropulseur automobile par la méthode de la focalisation bayésienne dans le cadre du projet Ecobex. Le champ acoustique cyclo-stationnaire généré par un ventilateur automobile a finalement été analysé par la méthode d'holographie acoustique de champ proche temps réel. / Experimental characterization of acoustic sources is one of the essential steps for reducing noise produced by industrial machinery. The aim of the thesis is to develop a complete procedure to localize and quantify both stationary and non-stationary sound sources radiating on a surface mesh by the back-propagation of a pressure field measured by a microphone array. The inverse problem is difficult to solve because it is generally ill-conditioned and subject to many sources of error. In this context, it is crucial to rely on a realistic description of the direct sound propagation model. In the frequency domain, the equivalent source method has been adapted to the acoustic imaging problem in order to estimate the transfer functions between the source and the antenna, taking into account the wave scattering. In the time domain, the propagation is modeled as a convolution product between the source and an impulse response described in the time-wavenumber domain. It seemed appropriate to use a Bayesian approach to use all the available knowledge about sources to solve this problem. A priori information available about the acoustic sources have been equated and it has been shown that taking into account their spatial sparsity or their omnidirectional radiation could significantly improve the results. In the assumptions made, the inverse problem solution is written in the regularized Tikhonov form. The regularization parameter has been estimated by an empirical Bayesian approach. Its superiority over methods commonly used in the literature has been demonstrated through numerical and experimental studies. In the presence of high variability of the signal to noise ratio over time, it has been shown that it is necessary to update its value to obtain a satisfactory solution. Finally, the introduction of a missing variable to the problem reflecting the partial ignorance of the propagation model could improve, under certain conditions, the estimation of the complex amplitude of the sources in the presence of model errors. The proposed developments have been applied to the estimation of the sound power emitted by an automotive power train using the Bayesian focusing method in the framework of the Ecobex project. The cyclo-stationary acoustic field generated by a fan motor was finally analyzed by the real-time near-field acoustic holography method.

La conjugaison de phase ultrasonore à couplage par l’air basée sur une céramique magnétostrictive et une membrane de filtration poreuse pour la microscopie et la vélocimétrie de micro écoulements a été développée. Dans ce but, dans le cadre de l’acoustique géométrique un système d’équations pour décrire mathématiquement le passage par l’interface entre l’élément actif du système de conjugaison de phase confocale – milieu de propagation a été développé.On a développé et réalisé une technique de codage de phase par m-séquence pour l’enregistrement des faibles signaux conjugués en phase. Cette technique a permis de travailler plus efficacement avec fort bruit et des signaux qui se trouvent sous le niveau de bruit. Aussi cette technique a permis d’améliorer une méthode de vélocimétrie des écoulements gazeux.On a développé et réalisé une technique d’adaptation d’impédance acoustique basée sur la membrane de filtration poreuse imprégnée par de l’huile. Cette technique a permis d’optimiser les conditions de transmission de l’onde à l’interface air–ferrite aux fréquences basse dans bande du MHz.Les applications possibles de l’effet de conjugaison de phase paramétrique à la vélocimétrie des écoulements gazeux et à la microscopie à couplage par l’air ont été présentées. L’application de l’effet de conjugaison de phase permet d’améliorer les performances des méthodes de vélocimétrie et de microscopie ultrasonores à couplage par l’air. Les méthodes élaborées a repoussé les limites d’applications pratiques de l’effet de conjugaison de phase et peuvent être utilisées pour le développement des dispositifs en vélocimétrie, microscopie et tomographie ultrasonore des écoulements gazeux / Air-coupled wave phase conjugation technique, based on magneto-acoustic interaction and porous membrane filters, for microscopy and velocity measurements of gas micro flows is under investigation. For this reason in the frame of ray acoustics the base system of equations for mathematical model of phase conjugate wave passage through the interface active element of con-focal WPC system – medium of propagation is developed. The phase coding technique by pseudonoise M-sequence was used for registration of weak acoustical phase conjugate signals. This method has allowed to work more effectively with strong noisy and being under noise level phase conjugate signals. Also this method has allowed improving a method of gas flow velocimetry.It is developed and realized the technology of acoustical matching on base of thin polycarbonate porous membrane filters impregnated by oil. This technology has allowed optimizing the conditions of wave transmission through the interface air–ferrite in the low megahertz frequency range.Possible applications of phase conjugate waves in air are shown. Results of investigations of air-coupled wave phase conjugation technics can serve for drawing up of new methods ultrasonic velocimetry and microscopy in technical industrial applications. The elaborated methods expand limits of application and can be used for development of devices of ultrasonic microscopy, tomography and velocimetry of gas micro flows

Für die Optimierung akustischer Eigenschaften von Räumen ist die Verbesserung deren numerischer Simulationen von entscheidender Bedeutung. Im unteren Frequenzbereich hängt in vielen Fällen die Qualität der Lösungen stark von der Kenntnis akustischer Wandadmittanzen ab. Die vorliegende Arbeit umfasst die Entwicklung und Untersuchung verschiedener auf deterministischen Diskretisierungen des akustischen Randwertproblems basierender Formulierungen zur globalen Bestimmung frequenzabhängiger Admittanzparameter. Mit Admittanzen kann das Reflexions- und Absorptionsverhalten von Wänden quantifiziert werden. Der vorgestellte Ansatz der globalen Admittanzbestimmung in Innenräumen ermöglicht die Berücksichtigung schrägen Schalleinfalls. Die Methode sieht ein Experiment vor, bei dem das Schallfeld mit Mikrofonen abgetastet, alle vorhandenen Schallquellen bestimmt sowie die Geometrie des akustischen Raumes erfasst werden. Mit den in der Arbeit entwickelten Algorithmen wird eine globale Admittanzverteilung für den gesamten Rand aus diesen Daten berechnet. Mit Hilfe erfolgreich identifizierter Admittanzverläufe sollen Simulationen niederfrequenter Wellenausbreitungen in Räumen auch komplizierter Geometrien und Oberflächenbeschaffenheiten durch Hinzunahme von Admittanzrandbedingungen ermöglicht und verbessert werden. Die Bestimmung von Wandadmittanzen aus partiell bekannten Schalldruckwerten wird mathematisch als inverses Problem eingeordnet. Für die inversen Algorithmen werden die Methoden der Randelemente (BE) und der finiten Elemente (FE) zur Diskretisierung des akustischen Randwertproblems verwendet. Aus den Gleichungen der BE-Diskretisierung lässt sich ein schlecht konditioniertes, aber dafür lineares Gleichungssystem für das inverse Problem finden, während die FE-basierte Formulierung ein nichtlineares, aufgrund der Komplexität des Problems meist ebenfalls schlecht konditioniertes Optimierungsproblem darstellt. Ein wesentliches Ergebnis dieser Arbeit ist die Gegenüberstellung der linearen und nichtlinearen Algorithmen des inversen Problems in Hinblick auf deren Herleitungen, die umgesetzten Berechnungsverfahren und der sich stark unterscheidenden Lösungsqualitäten. Untersuchungen der Admittanzrekonstruktion an zwei- und dreidimensionalen theoretischen Modellen verdeutlichen die Einflüsse der Modellgenauigkeit, des Messumfanges und des Messrauschens auf die Ergebnisse der inversen Algorithmen. Anhand der Anwendung auf Messdaten eines bei Brüel & Kjaer durchgeführten Experimentes wird das inverse Verfahren der globalen Admittanzbestimmung einem Praxistest unterzogen. / Reflection and absorption of sound waves on boundaries play a determining role for the optimization of acoustical properties in closed rooms. Above all the geometry and dynamic behavior of the wall structure are responsible for it. These boundary terms are quantifiable within the scope of numerical acoustics by the so-called admittance boundary conditions of the acoustical boundary value problem. Especially at low frequencies the quality of acoustical simulation depends strongly on the recognition of boundary admittances. The present work includes the development of two different inverse algorithms based on deterministic discretization methods for the global determination of frequency-dependent boundary admittance parameters. The approach of global determination of admittances allows to take account for non-perpendicular wave incident. For the method to work an experiment shall be initially conducted. In that process all present sound sources and microphone arrays scanning the sound field must be located and measured and a model of the geometry of the room needs to be created. The developed algorithms calculate then a global admittance distribution based on this data. Using successfully identified admittance characteristics as admittance boundary condition, low frequency simulation in rooms of complex geometry and arbitrary consistency of the surface shall be improved. Identifying boundary admittances out of partially measured sound pressure data is classifiable as inverse acoustic problem. In order to develop inverse formulations the acoustical boundary value problem is discretized by means of the Boundary Element and the Finite Element Method. The inverse formulation of the Boundary Element equations composes an ill-posed but linear system of equations. In contrast, based on Finite Elements only a nonlinear optimization problem can be set up that often features a bad condition due to the complexity of the inverse problem. The comparison of these linear and nonlinear algorithms of the inverse acoustic problem of global determination of boundary admittances in respect of derivation, implemented solution techniques and differing solution qualities states an essential result of this work. The investigation of admittance reconstruction at two and three-dimensional theoretical models reveal the influences of model accuracy, measurement expense and noise on measured data onto the results of both inverse algorithms. Finally, the problem of global admittance determination is subjected to experimentally obtained data (at Brüel & Kjaer) in order to check for practical applicability.

The theory of radiative transfer is applied to the problem of multiple wave scattering in a one-dimensional multilayer. A new mathematical model of a multilayer is presented in which both the refractive index and width of each layer are randomized. The layer widths are generated by a new probability distribution which allows for strong layer width disorder. An expression for the transport mean free path of the multilayer is derived based on its single-scattering properties. It will be shown that interference between the field reflected from adjacent layer interfaces remains significant even in the presence of strong layer width disorder. It will be proven that even when the scattering is weak, the field in a random multilayer localizes at certain frequencies. The effect of increasing layer width randomization on this form of localization is quantified. The radiative transfer model of time-harmonic scattering in multilayers is extended to narrow-band pulse propagation in weakly scattering media. The tendency of pulses to broaden in this medium is discussed. A radiative transport model of the system is developed and compared to numerical solutions of the wave equation. It is observed that pulse broadening is not described by simple transfer theory. The radiative transfer model is extended by the addition of a Laplacian term in an attempt to model the effect of ensemble average pulse broadening. Numerical simulation results in support of this proposal are given, and applications for the theory suggested. Finally, the problem of acoustic wave scattering by planar screens is considered. The study was motivated by the idea that multiple scattering experiments may prove possible in a medium composed of such scatterers. Successful multiple scattering in a medium of planar scatterers will depend on the scattering cross-section at angles away from normal incidence. The scattering cross-section is calculated for a circular disc using a new technique for solving the acoustic wave equation on planar surfaces. The method is validated by comparison with available analytic solutions and the geometric theory of diffraction.

The theory of radiative transfer is applied to the problem of multiple wave scattering in a one-dimensional multilayer. A new mathematical model of a multilayer is presented in which both the refractive index and width of each layer are randomized. The layer widths are generated by a new probability distribution which allows for strong layer width disorder. An expression for the transport mean free path of the multilayer is derived based on its single-scattering properties. It will be shown that interference between the field reflected from adjacent layer interfaces remains significant even in the presence of strong layer width disorder. It will be proven that even when the scattering is weak, the field in a random multilayer localizes at certain frequencies. The effect of increasing layer width randomization on this form of localization is quantified. The radiative transfer model of time-harmonic scattering in multilayers is extended to narrow-band pulse propagation in weakly scattering media. The tendency of pulses to broaden in this medium is discussed. A radiative transport model of the system is developed and compared to numerical solutions of the wave equation. It is observed that pulse broadening is not described by simple transfer theory. The radiative transfer model is extended by the addition of a Laplacian term in an attempt to model the effect of ensemble average pulse broadening. Numerical simulation results in support of this proposal are given, and applications for the theory suggested. Finally, the problem of acoustic wave scattering by planar screens is considered. The study was motivated by the idea that multiple scattering experiments may prove possible in a medium composed of such scatterers. Successful multiple scattering in a medium of planar scatterers will depend on the scattering cross-section at angles away from normal incidence. The scattering cross-section is calculated for a circular disc using a new technique for solving the acoustic wave equation on planar surfaces. The method is validated by comparison with available analytic solutions and the geometric theory of diffraction.

The theory of radiative transfer is applied to the problem of multiple wave scattering in a one-dimensional multilayer. A new mathematical model of a multilayer is presented in which both the refractive index and width of each layer are randomized. The layer widths are generated by a new probability distribution which allows for strong layer width disorder. An expression for the transport mean free path of the multilayer is derived based on its single-scattering properties. It will be shown that interference between the field reflected from adjacent layer interfaces remains significant even in the presence of strong layer width disorder. It will be proven that even when the scattering is weak, the field in a random multilayer localizes at certain frequencies. The effect of increasing layer width randomization on this form of localization is quantified. The radiative transfer model of time-harmonic scattering in multilayers is extended to narrow-band pulse propagation in weakly scattering media. The tendency of pulses to broaden in this medium is discussed. A radiative transport model of the system is developed and compared to numerical solutions of the wave equation. It is observed that pulse broadening is not described by simple transfer theory. The radiative transfer model is extended by the addition of a Laplacian term in an attempt to model the effect of ensemble average pulse broadening. Numerical simulation results in support of this proposal are given, and applications for the theory suggested. Finally, the problem of acoustic wave scattering by planar screens is considered. The study was motivated by the idea that multiple scattering experiments may prove possible in a medium composed of such scatterers. Successful multiple scattering in a medium of planar scatterers will depend on the scattering cross-section at angles away from normal incidence. The scattering cross-section is calculated for a circular disc using a new technique for solving the acoustic wave equation on planar surfaces. The method is validated by comparison with available analytic solutions and the geometric theory of diffraction.

The theory of radiative transfer is applied to the problem of multiple wave scattering in a one-dimensional multilayer. A new mathematical model of a multilayer is presented in which both the refractive index and width of each layer are randomized. The layer widths are generated by a new probability distribution which allows for strong layer width disorder. An expression for the transport mean free path of the multilayer is derived based on its single-scattering properties. It will be shown that interference between the field reflected from adjacent layer interfaces remains significant even in the presence of strong layer width disorder. It will be proven that even when the scattering is weak, the field in a random multilayer localizes at certain frequencies. The effect of increasing layer width randomization on this form of localization is quantified. The radiative transfer model of time-harmonic scattering in multilayers is extended to narrow-band pulse propagation in weakly scattering media. The tendency of pulses to broaden in this medium is discussed. A radiative transport model of the system is developed and compared to numerical solutions of the wave equation. It is observed that pulse broadening is not described by simple transfer theory. The radiative transfer model is extended by the addition of a Laplacian term in an attempt to model the effect of ensemble average pulse broadening. Numerical simulation results in support of this proposal are given, and applications for the theory suggested. Finally, the problem of acoustic wave scattering by planar screens is considered. The study was motivated by the idea that multiple scattering experiments may prove possible in a medium composed of such scatterers. Successful multiple scattering in a medium of planar scatterers will depend on the scattering cross-section at angles away from normal incidence. The scattering cross-section is calculated for a circular disc using a new technique for solving the acoustic wave equation on planar surfaces. The method is validated by comparison with available analytic solutions and the geometric theory of diffraction.

La prédiction du bruit de roulement ferroviaire est en enjeu majeur pour la maitrise des nuisances sonores. Au point de contact roue/rail, la roue et la voie sont excités de manière dynamique, ce qui enclenche le rayonnement du bruit de roulement. Les réponses vibratoires au point de contact ainsi que les taux de décroissance des ondes sont des données primordiales pour simuler de manière précise le bruit de roulement. Or, la dimension infinie de la voie ferrée conduit bien souvent à des modèles éléments finis coûteux et non adaptés à la recherche de solutions innovantes. La thèse a pour objectifs de proposer un modèle vibratoire de voie en éléments finis qui prenne en compte la dimension infinie périodique de la voie, mais aussi d’inclure une portion de voie non-périodique sur laquelle des solutions anti-vibratiles peuvent être testées. La propagation des vibrations est exprimée sous la forme d’une décomposition en ondes par la méthode WFE (Wave Finite Element). Le calcul de la réponse vibratoire de la voie périodique infinie est obtenu à partir du déplacement d’une cellule physique longue d’environ 0.6 m. Pour réduire les temps de calcul nécessaires à sa condensation dynamique, une méthode de bi-périodisation est proposée. Le couplage entre les méthodes éléments finis et WFE est développé pour prendre en considération les supports élastiques dans cette cellule. Les comparaisons avec des mobilités expérimentales ainsi que des taux de décroissance montrent un très bon accord calculs-mesures. Enfin, le modèle développé dans cette thèse a permis de tester l’efficacité d’une solution anti-vibratile innovante développée au sein du projet CERVIFER. Celle-ci offre un comportement bi-mode, elle assouplit les supports autour de la roue préservant ainsi l’infrastructure, mais elle rigidifie les supports loin de la roue pour augmenter les taux de décroissance. Les résultats numériques se révèlent prometteurs en termes d’efficacité du dispositif et entrevoient une poursuite du développement de cette solution anti-vibratile. / Railway noise is a critical issue concerning environmental noise. At the wheel/rail contact point, both the wheel and the track are dynamically excited and vibrate together to emit the well known rolling noise. The point receptance of the rail and the track decay rates are important quantities to accurately predict wheel-rail noise emission. However, the infinite dimension of the track leads to cumbersome numerical finite-element (FE) models and not adapted to assist the research of innovative solutions. The goals of this thesis are to build an efficient numerical model for calculating the vibration from an infinite railway track, but also to include a central non-periodic part with the aim of testing anti-vibration solutions. The vibration propagation along the track is expressed as a sum of different waves using the WFEM (Wave Finite Element Method). The displacements of a 0.6 m unit cell lead to the computation of the whole track. To reduce the dynamic condensation of this cell, a bi-periodic method is proposed in this thesis. The FEM - WFEM coupling is proposed to easily include elastic supports inside the unit cell. Results show a good correlation between test and calculation. Finally, the model proposed in this thesis was used to test the efficiency of an innovative anti-vibration solution developed within the CERVIFER project. It is a dual mode device which makes the supports softer around the wheel to protect the infrastructure, and stiffer away from the wheel to increase the track decay rates. The numerical results revealed to be really promising, and they will permit to pursue the development of this anti-vibration solution.