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

La técnica de las ondas de Lamb acopladas por aire representa un importante avance en el área de los Ensayos No Destructivos (END) de materiales laminares.Sin embargo la compleja naturaleza de las vibraciones mecánicas encontradas en acústica, hacen que el análisis y el estudio de esta área del conocimiento sea un tema muy complejo. De allí que la posibilidad de contar con una herramienta de simulación de software que permita la evaluación y prueba de diferentes configuraciones de excitación y recepción acústica utilizando la flexibilidad de un modelo de computadora sea de una gran utilidad y ayuda.El objetivo de la presente tesis es proveer al área de los END con un software de simulación gratuito: The LAMB Matlab® toolbox basado en el modelo del software libre de la GNU.El software es capaz de simular el comportamiento de sistemas de END basados en ondas de Lamb acopladas por aire en láminas isótropas simples utilizando transductores tipo array.El programa se basa en un arreglo tipo C-scan de un sistema de END y está compuesto por tres bloques principales: 1) Excitación, 2) Propagación y 3) Recepción.La verificación individual del funcionamiento de dichos módulos se presenta a lo largo de la tesis mediante una serie de comparaciones entre simulaciones y datos experimentales provenientes de diferentes pruebas. Por otro lado, la validación del programa completo se llevo a cabo por medio de experimentos en láminas de cobre y aluminio; utilizando un sistema real de END por ondas de Lamb acopladas en aire mediante arrays cóncavos.La influencia negativa en el desempeño general de dicho sistema de END real basado en este tipo de transductores se comprobó efectivamente mediante el simulador desarrollado. Esto se debió fundamentalmente al efecto de directividad de los sensores individuales en los transductores y a la simetría cóncava de los arrays.Para emular este comportamiento la tesis presenta un modelo geométrico bidimensional simple de un filtro espacial, junto a las simulaciones de un nuevo tipo de array plano propuesto.El programa desarrollado comprobó así mismo la naturaleza coherente de los campos acústicos emitidos en aire por las láminas sujetas a vibraciones de Lamb. Esto se realizó mediante la implementación de un conformador de haz simple de suma y demora; constituyéndose así la etapa inicial de procesamiento de señal del bloque de recepción del programa.El objetivo principal del presente trabajo fue contribuir con un modelo operativo de simulación y prueba de nuevos diseños de arrays e implementación de estrategias de procesado de señal útiles en sistemas de END basados en ondas de Lamb acopladas por aire.Finalmente, si bien el objetivo de la calibración del programa no se pudo conseguir; si se logró efectivamente un notable grado de similitud con un sistema de END real. / Air-coupled ultrasonic Lamb waves represent an important advance in Non- Destructive Testing and Evaluation (NDT & NDE) techniques of plate materials and structures. Examples of these advances are the characterization and quality assessment of laminate materials in manufacturing processes, the location of damaged parts in aircrafts and structure monitoring in the aerospace industry.However the rich and complex nature of mechanical vibrations encountered in acoustics make the subject of analysis and study of these systems a very complex task. Therefore a simulation tool that permits the evaluation and testing of different configuration scenarios using the flexibility of a computer model is an invaluable aid and advantage.The objective of this thesis is to provide the field of NDT with free open source software i.e. the LAMB Matlabrtoolbox. The toolbox is capable of simulating the behaviour of Lamb wave based NDE systems for single ideal isotropic laminates using air-coupled ultrasonic arrays. The programme usesa pitch-catch type of a Cscan NDE arrangement and is composed of three integrated sections each individually modelling a feature in the system: 1) Excitation, 2) Propagation, and 3) Reception.For assessment of the individual modules of the toolbox the thesis presents comparisons between each section simulations and the data obtained from different acoustic experiments. The validation of the complete simulator was carried out by evaluation tests on the copper and aluminium plates by use of a real hardware prototype of a Lamb wave based NDE system with aircoupled concave arrays.The negative impact on the performance of the real air-coupled NDE systembased on concave arrays was effectively confirmed by the programme. This was produced by the inherent directivity of the individual sensors as well as their concave arrangement. To emulate this behaviour the thesis introduces a simple two-dimensional geometric model for the inclusion of the spatial filtering effect of the sensors plus a group of simulations for a new proposed air-coupled plane array transducer.The software also verified the spatial coherent nature of the Lamb wave fields emitted by a plate in air. This was demonstrated by the implementation of a delay and sum beamformer to constitute an initial signal processing stage in the reception section.

Para que um transdutor ultrassônico gere e transmita um pulso curto e receba ecos com elevada sensibilidade, além de uma camada de retaguarda que absorva as ondas emitidas para trás, é necessário que haja um bom casamento de impedância acústica entre a cerâmica piezelétrica e o meio externo (camada de acoplamento). Quando comparado ao acoplamento em líquido, o acoplamento em ar é ainda mais complexo, pois este tipo resulta em perdas elevadas durante a transmissão e a recepção dos sinais acústicos, devido à grande diferença de impedância acústica entre a cerâmica e o ar. Certas aplicações requerem um acoplamento em ar e, para isso, os transdutores ultrassônicos usados devem ter banda larga, além de uma baixa impedância acústica. O aumento da largura de banda de um transdutor piezelétrico pode ser alcançado com o emprego de piezocompósitos, de uma camada de retaguarda, de camadas de acoplamento frontal e melhorias na parte eletrônica. A contribuição deste trabalho visa a estudar e desenvolver piezocompósitos com maior largura de banda para aplicação em transdutores de ultrassom para acoplamento em ar. De modo geral, os piezocompósitos possibilitam um maior fator de acoplamento eletromecânico e uma menor impedância acústica quando comparado às cerâmicas piezelétricas convencionais. Neste trabalho foram realizadas a modelagem, a construção e a caracterização de três tipos de piezocompósitos: piezocompósitos com gradação da densidade, piezocompósitos 2-2, e piezocompósitos 1-3. Naqueles com gradação da densidade,variaram-se os parâmetros profundidade, largura e distribuição dos cortes. O método de elementos finitos foi utilizado para analisar a influência dos parâmetros dos cortes. Os piezocompósitos foram construídos a partir de piezocerâmicas circulares e retangulares. Alguns dos piezocompósitos construídos foram submetidos a experimentos de interferometria a laser, mostrando a variação da distribuição dos deslocamentos máximos na superfície em função da frequência. A partir do espectro de frequência da condutância e dos valores inferiores e superiores da largura de banda foram analisados os deslocamentos máximos nas diversas regiões da superfície dos piezocompósitos. Nos piezocompósitos gradados observou-se que os deslocamentos máximos em determinadas regiões da superfície do piezocompósito dependiam da frequência de excitação. Desse modo, os piezocompósitos gradados apresentaram fator de acoplamento eletromecânico e largura de banda maiores do que os dos piezocompósitos 1-3. Transdutores com emissão em ar construídos a partir de piezocompósito gradado e do tipo 1-3 foram caracterizados e medidos os parâmetros largura de banda e fator de acoplamento eletromecânico. O transdutor construído a partir do piezocompósito gradado apresentou maior largura de banda quando comparado com o transdutor do tipo 1-3. / In order to generate and emit a short pulse and receive the echoes with high sensitivity, an ultrasound transducer requires a backing layer to attenuate the signal going backwards and a matching layer to match the acoustical impedances of the piezoceramic and the medium. When compared to liquid coupling, air coupling is further complicated because the large mismatch in acoustic impedance between the ceramic and air results in high losses during transmission and reception of acoustic signals. Certain applications require air-coupling and, therefore, the ultrasonic transducers used must be broadband and have low acoustic impedance. The increase of the bandwidth of a piezoelectric transducer can be achieved with the use of piezocomposites, a back layer, frontal coupling layers and improvements in the electronic part. The contribution of this work aims to study and develop piezocomposites with higher bandwidth for application in ultrasonic transducers with air coupling. In general, the piezocomposites allow a higher electromechanical coupling factor and a lower acoustic impedance when compared to conventional piezoelectric ceramics. In this work, three types of piezocomposites were made: piezocomposites with density gradation, piezocomposites 2-2, and piezocomposites 1-3. In those with density gradation, depth, width and distribution of the cuts were varied. The finite element method was used to analyze the influence of the cut parameters. The piezocomposites were constructed from circular and rectangular piezoceramics. Some of the constructed piezocomposites were submitted to laser interferometry experiments, which showed the variation of the distribution of the maximum displacements in the surface as a function of the frequency. From the frequency spectrum of the conductance curve and of the lower and upper values of bandwidth, the maximum displacements in the various surface regions of the piezocomposites were analyzed. In the graded piezocomposites it was observed that the maximum displacements in certain regions of the surface of the piezocomposite depend on the frequency of excitation. Thus, the graded piezocomposites presented higher electromechanical coupling factor and bandwidth than the piezocomposites 1- 3. Air-coupled transducers constructed from graded piezocomposite and type 1-3 were characterized and measured the parameters bandwidth and electromechanical coupling factor. The transducer constructed from the graded piezocomposite presented higher bandwidth when compared to the type 1-3 transducer.

Para que um transdutor ultrassônico gere e transmita um pulso curto e receba ecos com elevada sensibilidade, além de uma camada de retaguarda que absorva as ondas emitidas para trás, é necessário que haja um bom casamento de impedância acústica entre a cerâmica piezelétrica e o meio externo (camada de acoplamento). Quando comparado ao acoplamento em líquido, o acoplamento em ar é ainda mais complexo, pois este tipo resulta em perdas elevadas durante a transmissão e a recepção dos sinais acústicos, devido à grande diferença de impedância acústica entre a cerâmica e o ar. Certas aplicações requerem um acoplamento em ar e, para isso, os transdutores ultrassônicos usados devem ter banda larga, além de uma baixa impedância acústica. O aumento da largura de banda de um transdutor piezelétrico pode ser alcançado com o emprego de piezocompósitos, de uma camada de retaguarda, de camadas de acoplamento frontal e melhorias na parte eletrônica. A contribuição deste trabalho visa a estudar e desenvolver piezocompósitos com maior largura de banda para aplicação em transdutores de ultrassom para acoplamento em ar. De modo geral, os piezocompósitos possibilitam um maior fator de acoplamento eletromecânico e uma menor impedância acústica quando comparado às cerâmicas piezelétricas convencionais. Neste trabalho foram realizadas a modelagem, a construção e a caracterização de três tipos de piezocompósitos: piezocompósitos com gradação da densidade, piezocompósitos 2-2, e piezocompósitos 1-3. Naqueles com gradação da densidade,variaram-se os parâmetros profundidade, largura e distribuição dos cortes. O método de elementos finitos foi utilizado para analisar a influência dos parâmetros dos cortes. Os piezocompósitos foram construídos a partir de piezocerâmicas circulares e retangulares. Alguns dos piezocompósitos construídos foram submetidos a experimentos de interferometria a laser, mostrando a variação da distribuição dos deslocamentos máximos na superfície em função da frequência. A partir do espectro de frequência da condutância e dos valores inferiores e superiores da largura de banda foram analisados os deslocamentos máximos nas diversas regiões da superfície dos piezocompósitos. Nos piezocompósitos gradados observou-se que os deslocamentos máximos em determinadas regiões da superfície do piezocompósito dependiam da frequência de excitação. Desse modo, os piezocompósitos gradados apresentaram fator de acoplamento eletromecânico e largura de banda maiores do que os dos piezocompósitos 1-3. Transdutores com emissão em ar construídos a partir de piezocompósito gradado e do tipo 1-3 foram caracterizados e medidos os parâmetros largura de banda e fator de acoplamento eletromecânico. O transdutor construído a partir do piezocompósito gradado apresentou maior largura de banda quando comparado com o transdutor do tipo 1-3. / In order to generate and emit a short pulse and receive the echoes with high sensitivity, an ultrasound transducer requires a backing layer to attenuate the signal going backwards and a matching layer to match the acoustical impedances of the piezoceramic and the medium. When compared to liquid coupling, air coupling is further complicated because the large mismatch in acoustic impedance between the ceramic and air results in high losses during transmission and reception of acoustic signals. Certain applications require air-coupling and, therefore, the ultrasonic transducers used must be broadband and have low acoustic impedance. The increase of the bandwidth of a piezoelectric transducer can be achieved with the use of piezocomposites, a back layer, frontal coupling layers and improvements in the electronic part. The contribution of this work aims to study and develop piezocomposites with higher bandwidth for application in ultrasonic transducers with air coupling. In general, the piezocomposites allow a higher electromechanical coupling factor and a lower acoustic impedance when compared to conventional piezoelectric ceramics. In this work, three types of piezocomposites were made: piezocomposites with density gradation, piezocomposites 2-2, and piezocomposites 1-3. In those with density gradation, depth, width and distribution of the cuts were varied. The finite element method was used to analyze the influence of the cut parameters. The piezocomposites were constructed from circular and rectangular piezoceramics. Some of the constructed piezocomposites were submitted to laser interferometry experiments, which showed the variation of the distribution of the maximum displacements in the surface as a function of the frequency. From the frequency spectrum of the conductance curve and of the lower and upper values of bandwidth, the maximum displacements in the various surface regions of the piezocomposites were analyzed. In the graded piezocomposites it was observed that the maximum displacements in certain regions of the surface of the piezocomposite depend on the frequency of excitation. Thus, the graded piezocomposites presented higher electromechanical coupling factor and bandwidth than the piezocomposites 1- 3. Air-coupled transducers constructed from graded piezocomposite and type 1-3 were characterized and measured the parameters bandwidth and electromechanical coupling factor. The transducer constructed from the graded piezocomposite presented higher bandwidth when compared to the type 1-3 transducer.

Le contrôle non destructif par ondes guidées générées et détectées par des transducteurs ultrasonores à couplage par air, présente deux avantages majeurs. Le premier réside dans la capacité des ondes guidées à transporter l’information sur la qualité du milieu sur une grande distance. De plus, l’absence d’un milieu de couplage liquide entre les capteurs et le milieu à tester, rend le contrôle plus commode. Ce travail consiste d’abord à développer un procédé de simulation numérique qui prend en considération de nombreux paramètres du système de contrôle. Dans une optique de réduire le nombre de degrés de liberté, un modèle hybride a été développé qui consiste en une combinaison entre un modèle analytique basé sur l’intégrale de Kirchhoff pour la propagation des ultrasons dans l’air et un modèle éléments finis de la propagation des ondes guidées dans le matériau. La mesure des caractéristiques du transducteur à couplage par air (efficacité de l’émetteur et sensibilité du récepteur) permet, d’une part, de calculer la valeur exacte de la pression dans l’air et les valeurs exactes des champs de contraintes et de déplacements dans la structure, pour une tension et une fréquence d’excitation, et d’autre part, de remonter à la tension électrique aux bornes de ce récepteur pour une pression rayonnée par le matériau. Par suite, cette caractérisation rend possible la comparaison entre les prédictions numériques de la réponse (en niveau de tension) du système et les mesures expérimentales correspondantes. A la lumière du modèle numérique développé, une optimisation des paramètres du système de contrôle (angle, fréquence,diamètre, direction de propagation, champ proche et champ lointain) a été effectuée pour améliorer la pureté des modes guidés par le matériau. Une manipulation expérimentale, basée sur un transducteur à couplage par air pour l’émission et une sonde laser pour la réception, a été alors mise en place pour valider quelques prédictions numériques. Ensuite, on a étudié l’interaction des ondes guidées ultrasonores avec des défauts de type délaminage enfouis dans une plaque composite à symétrie quadratique. Pour cela, on a analysé la sensibilité des deux modes fondamentaux A0 et S0 au délaminage en terme de détectabilité. En parallèle, on a traité un problème inverse qui consiste à dimensionner un délaminage par le calcul du spectre fréquentiel du coefficient de réflexion. Enfin, on a mis en évidence le potentiel des transducteurs à couplage par air à ausculter des pièces aéronautiques impactées. / Non-destructive testing (NDT) using guided waves generated and detected by air-coupled ultrasonic transducers have two main advantages. First, this non-contact technique without coupled medium allows obvious convenience of use. Moreover, the ability of guided waves to carry information about medium quality over long distance. In this context, a numerical model has been developed, which takes into account many parameters of the control system. In order to reduce the number of degrees of freedom, a hybrid model has been developed which consists of a combination between an analytical model, based on the Kirchhoff integral for the propagation of ultrasound in air and a finite element model for the propagation of guided waves in the material. The measured characteristics (efficiency and sensitivity) of two air-coupled transducers allow the prediction of the accurate values of the pressure of bulk waves generated in air and the measurement of the pressure of the radiated field in air by guided waves propagating in a structure. This process enables the comparison between predicted and measured guided waves modes. Based on the hybrid model, an optimization of the parameters of the control system (angle, frequency, diameter, direction of propagation, near and far field) was performed to improve the purity of guided modes along the material plate. To validate some numerical predictions, an aircoupled ultrasonic transducer is used and oriented at a specific angle chosen for generating one specific Lambmode guided along a composite plate sample, and a laser probe measures the normal velocity at different locations on the surface of the plate. Then, the interaction of ultrasonic guided waves with delamination in acomposite plate was studied. In particular, the sensitivity of the two fundamental modes A0 and S0 was analyzed in order to predict the detectability of the defect. In parallel, the inverse problem is solved and the defect size is quantified by calculating the spectrum of the reflection coefficient. Finally, the potential of air-coupled transducers to examine an aircraft structure, has been demonstrated.

Ce travail de recherche propose l’algorithme de calcul pour la modélisation d’un scanner ultrasonore sans contact à ondes de surface. L’approche proposée permet de prendre en compte l’ouverture finie du récepteur, l’atténuation d’air et la réponse électrique he de l’ensemble émetteur-récepteur. Le milieu avec l’atténuation (air et milieu testé) est modélisé dans le domaine temporel à l’aide de la fonction de Green causale permettant la caractérisation large bande. Le réponse he est déterminée de manière expérimentale en utilisant la procédure spatialement développée, incluant la déconvolution des effets d’atténuation. Le modèle est implémenté numériquement en utilisant l’approche de la Représentation Discrète et les résultats obtenus sont validés expérimentalement. La technique chirp est utilisée afin d’améliorer le rapport signal/bruit. Il est démontré que lorsque l’atténuation dans l’air, la dimension de récepteur et la réponse he reconstituée avec précision sont correctement pris en compte, la réponse impulsionnelle du système peut être prédite avec l’erreur de 2-5 %. L’introduction de la taille du récepteur est essentielle pour la prédiction dans le champ proche. Le temps de calcul obtenu est considérablement plus court que le temps nécessaire pour les méthodes FEM. A l’aide de ce modèle l’influence des réglages du scanner est étudiée. Les résultats obtenus permettent de formuler des recommandations pour les réglages optimaux / In this research the time-domain model for the prediction of an acoustic field in an air-coupled, non-contact, surface wave scanner is proposed. The model takes into account the finite size of the aperture receiver, attenuation in air, and the electric response he of the emitter-receiver set he. The attenuation is characterized by a causal time-domain Green’s function, allowing the wideband attenuation of a lossy medium (air and solid tested sample) obeying the power law to be modelled. The response he is recovered experimentally using an original especially developed procedure which includes the deconvolution of air absorption effects. The model is implemented numerically using a Discrete Representation approach and validated experimentally. In order to improve the signal to noise ratio the chirp technique is used. It is shown that when the attenuation in air, the receiver size, and the accurately recovered response he, are correctly taken into account, the model allows the system’s impulse response to be very accurately predicted, with errors ranging between 2-5%. Inclusion of the size of the receiver dimension in the model appears to be crucial to the accuracy of the near field predictions. The obtained computation efficiency is much better that efficiency of FEM methods. The influence of typical user defined settings has been investigated. The obtained conclusions will be used as the recommendations for further use

Although several studies have proven the accuracy of using a non-contact, air-coupled receiver in nonlinear ultrasonic (NLU) Rayleigh wave measurements, inconsistent results have been observed when working with narrow specimens. The objectives of this research are first, to develop a 3D numerical finite element (FE) model which predicts nonlinear ultrasonic measurements and second, to apply the validated model on the narrow waveguide to determine causes of the previously observed experimental issues. The commercial FE-solver ABAQUS is used to perform these simulations. Constitutive law and excitation source properties are adjusted to match experiments conducted, considering inherent effects of the non-contact detection, such as frequency dependent pressure wave attenuation and signal averaging. Comparison of “infinite” and narrow width simulations outlines various influences which impair the nonlinear Rayleigh wave measurements. When the wave expansion is restricted, amplitudes of the fundamental and second harmonic components decrease more significantly and the Rayleigh wavefronts show an oscillating interaction with the boundary. Because of the air-coupled receiver’s finite width, it is sensitive to these edge effects which alter the observed signal. Thus, the narrow specimen adversely affects key factors needed for consistent measurement of material nonlinearity with an air-coupled, non-contact receiver.

Cette thèse porte sur le développement d'un traducteur ultrasonore multi-élément capacitif à couplage air (MEACUT) et son utilisation dans le domaine du contrôle non destructif (CND) de matériaux. Un modèle est employé pour simuler numériquement ce traducteur, et pour optimiser sa conception. Un prototype est ensuite fabriqué, puis caractérisé expérimentalement pour quantifier ses performances. Son originalité réside dans le fait qu'il possède une large bande passante en fréquence, tout en offrant la possibilité d'une focalisation variable. Ce prototype est alors employé pour la détection d'un endommagement causé par impact, dans une plaque composite. Il est clairement constaté que la résolution spatiale du procédé d'inspection employé (C-scan) est fortement améliorée grâce aux performances techniques du MEACUT. Enfin, un modèle hybride 3D est développé pour simuler, rapidement et intégralement, ce procédé de CND. Le très bon accord obtenu entre prédictions numériques et mesures expérimentales laisse présager que cet outil de simulation pourra servir à mettre au point d'autres expérimentations de CND, qui pourront à leur tour exploiter les performances du MEACUT. / This thesis focuses on the development of a Multi-Element Air-coupled Capacitive Ultrasonic Transducer (MEACUT) and its use in the field of non-destructive testing (NDT) of materials. A numerical model is used to simulate the translator, and to optimize its design. A prototype is then built and experimentally characterized to quantify its performance. Its originality lies in the fact that it has a broad frequency bandwidth while offering the possibility of a dynamic focusing. This prototype is then used for the detection of damage caused by impact, in a composite plate. It is clearly found that the spatial resolution of the inspection process employed (C-scan) is greatly improved thanks to the technical performance MEACUT. Finally, a 3D hybrid model is developed to simulate quickly and fully, the process of NDT. The good agreement obtained between numerical predictions and experimental measurements suggests that this simulation tool can be used to develop other NDT experiments, which may in turn exploit the performance of MEACUT.