This paper presents a modeling approach of eddy current Non Destructive Evaluation of Unidirectio... more This paper presents a modeling approach of eddy current Non Destructive Evaluation of Unidirectional Carbon Fiber Reinforcement Composite (UD-CFRC) rods, with taking into account of the capacitive effect. To construct the model, the following three steps must be respected. In the first step, the multilayer solenoidal air coil is modeled with an axisymmetric eddy current model formulated with a coupled finite element model (FEM) and an equivalent electrical circuit model (EECM), without taking into account the capacitive effect. The complex impedance of each coil layer is computed for several frequencies, and then it is introduced into the EECM with considering the equivalent capacitors of each layer and between all neighboring layers. After that, the total impedance of the coil is computed for each frequency. The difference between computed and measured impedances is minimized until reaching the convergence criterion of the objective function using the simulated annealing optimizati...
This paper present a high potential NDT technique based on electromagnetic induction and thermogr... more This paper present a high potential NDT technique based on electromagnetic induction and thermography method called induction thermography or eddy-current thermography applied to laminated CFRP composites. Accurate assessment of the performance of this technique requires the development and use of a specific multiphysics and multiscale computation code in which mesoscopic model is used in macroscopic scale simulations. Simulation results show that short time heating is advantageous.
In this paper, one proposes a model-assisted probability of detection approach to study the relia... more In this paper, one proposes a model-assisted probability of detection approach to study the reliability of detecting special defects. The approach is based on a 3-D finite-element T–<inline-formula> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> formulation with circuit coupling. This model is then applied to calculate performances of induction thermography method to detect thin open cracks in vessel reactor shell in nuclear installation.
The present work deals with the use of conformal mapping method in order to analysis multiples ax... more The present work deals with the use of conformal mapping method in order to analysis multiples axisymmetric defects using established transformations models [1] for eddy current problems in non-destructive testing (NDT) systems. The interest of such a transformation is the generation of electromagnetic field for axisymmetric problem from only the field distribution known in simpler 2D(x-y) geometry. The transformation technique
2019 IEEE 5th International Workshop on Metrology for AeroSpace (MetroAeroSpace)
This paper discusses the possible non-destructive testing (NDT) techniques for a novel bonding qu... more This paper discusses the possible non-destructive testing (NDT) techniques for a novel bonding quality evaluation technique based on comparison of different inspection methodologies. The goal of this paper is to guide a way for bonding quality evaluation with high reliability by comparing different NDT techniques including ultrasonic, electromagnetic, and thermography. The advantages and limitations of each different NDT technique have been reported systematically. Two case studies have been investigated with two different NDT techniques, namely ultrasonic and induction thermography. The results suggested the limitations and advantages of NDT techniques. In order to compensate the limitations of each technique, data fusion of the selected techniques is proposed.
The European Physical Journal Applied Physics, 2016
Using a 3D finite elements simulation tool, a study on the flaw detection capacity of the non des... more Using a 3D finite elements simulation tool, a study on the flaw detection capacity of the non destructive testing (NDT) induction thermography (IT) technique for laminated carbon fiber reinforced polymers (CFRP) composites is presented. Delamination and fiber rupture flaw occurring at the elementary-ply scale are considered. In order to reduce the impact of measurement noise on the flaw detectability, several signal processing techniques are proposed.
International Journal of Electronics, Apr 23, 2007
ABSTRACT Simulated annealing (SA) adapted to continuous variables is used lo determine the synapt... more ABSTRACT Simulated annealing (SA) adapted to continuous variables is used lo determine the synaptic coefficients of an analogue multilayer neural network, approximating any continuous function of one or several variables. The ‘open’ electrical simulator SPICE-PAC driven by SA produces a globally optimal set of synaptic weights, in a reasonable time and without requiring heavy and inaccurate gradient computations, We illustrate and improve our weights tuning strategy through simple examples.
International Journal of Electronics, Apr 23, 2007
ABSTRACT An efficient new method, based on the coupling between an enhanced simulated annealing a... more ABSTRACT An efficient new method, based on the coupling between an enhanced simulated annealing algorithm and the SPICE-PAC ‘open’ circuit simulator, is proposed for minimizing objective functions describing circuit performance optimization problems or component model fitting to experimental data. To keep the number of objective function evaluations and CPU times to the lowest possible level, we focus our attention on two features: first, we build an original partitioning technique for splitting large n-dimensional problems; then we carefully study variables discretization, (which is necessary for applying the simulated annealing method to continuous problems). To illustrate the efficiency of our method, we show how to determine the 40 MOS transistor model parameters, through fitting the model to experimental data.
This work mainly deals with the characterization of the delaminations in the fibre-metal laminate... more This work mainly deals with the characterization of the delaminations in the fibre-metal laminates as the Glare®. We present a direct model based on Electromagnetic Coupled Circuit Method (ECCM). This model has been improved and coupled with analytical computations to avoid the discretization of the load. The number of unknowns needed for obtaining the sensor impedance variations is reduced and computation of the direct model has been sped up. Thus, an optimization algorithm could be applied to obtain the material physical properties and the delamination geometrical parameters in multilayer materials. The particle swarm optimization (PSO), a recent powerful optimization technique, is then coupled with the direct model in an inversion process, providing the desired parameters. Some examples, linked to aeronautics, are presented: thickness of layers and delamination geometrical characterization in fiber-metal laminate material as Glare®. Experimental results are shown and analyzed in ...
A semi-analytical forward model based on the electromagnetic coupled cir-cuits method is presente... more A semi-analytical forward model based on the electromagnetic coupled cir-cuits method is presented. This model allows to simulate the impedance variation of a ferrite-cored sensor above a controlled material. The computational speed is increased by determinig the current density in coil using the Kelvin analytical distribution. This forward model provides a good accuracy with respect to experimental measurements. 1 Main objectives ECNDT is generally used in such frequency domain that intrinsic skin and proximity effects of the sensor are rather important (freq. between 100Hz and some MHz). Most of well-used models don't consider these effects which can change considerably the impedance of the sensor. In this paper, we propose a semi-analytical forward model which takes into account these phenomena [1, 4]. Our axisymmetrical model is based on the electromagnetic coupled circuits method (ECCM) [2, 3] which allows to determine the sensor impedance. As this model is fast-running, we...
Modélisation et simulation pour l'analyse et l'optimisation des systèmes industriels et l... more Modélisation et simulation pour l'analyse et l'optimisation des systèmes industriels et logistiques" MOSIM'04 – du 1 er au 3 septembre 2004 -Nantes (France) RÉSUMÉ : Cet article décrit la conception d'une Machine à Réluctance Variable (MRV) basse vitesse destinée à des applications éolienne. On s'intéresse particulièrement à la modélisation et au dimensionnement de la structure de la machine en optimisant d'une part le couple et d'autre part le couple massique. Les dimensions sont obtenues en utilisant un algorithme génétique couplé avec la méthode des éléments finis pour la résolution des équations électromagnétique. . simple refroidir. autonome. L'objectif est d'optimiser la structure de la MOTS-CLÉS : Machine à Réluctance Variable, Optimisation, Algorithme génétique, Eolienne.
This paper presents a modeling approach of eddy current Non Destructive Evaluation of Unidirectio... more This paper presents a modeling approach of eddy current Non Destructive Evaluation of Unidirectional Carbon Fiber Reinforcement Composite (UD-CFRC) rods, with taking into account of the capacitive effect. To construct the model, the following three steps must be respected. In the first step, the multilayer solenoidal air coil is modeled with an axisymmetric eddy current model formulated with a coupled finite element model (FEM) and an equivalent electrical circuit model (EECM), without taking into account the capacitive effect. The complex impedance of each coil layer is computed for several frequencies, and then it is introduced into the EECM with considering the equivalent capacitors of each layer and between all neighboring layers. After that, the total impedance of the coil is computed for each frequency. The difference between computed and measured impedances is minimized until reaching the convergence criterion of the objective function using the simulated annealing optimizati...
This paper present a high potential NDT technique based on electromagnetic induction and thermogr... more This paper present a high potential NDT technique based on electromagnetic induction and thermography method called induction thermography or eddy-current thermography applied to laminated CFRP composites. Accurate assessment of the performance of this technique requires the development and use of a specific multiphysics and multiscale computation code in which mesoscopic model is used in macroscopic scale simulations. Simulation results show that short time heating is advantageous.
In this paper, one proposes a model-assisted probability of detection approach to study the relia... more In this paper, one proposes a model-assisted probability of detection approach to study the reliability of detecting special defects. The approach is based on a 3-D finite-element T–<inline-formula> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> formulation with circuit coupling. This model is then applied to calculate performances of induction thermography method to detect thin open cracks in vessel reactor shell in nuclear installation.
The present work deals with the use of conformal mapping method in order to analysis multiples ax... more The present work deals with the use of conformal mapping method in order to analysis multiples axisymmetric defects using established transformations models [1] for eddy current problems in non-destructive testing (NDT) systems. The interest of such a transformation is the generation of electromagnetic field for axisymmetric problem from only the field distribution known in simpler 2D(x-y) geometry. The transformation technique
2019 IEEE 5th International Workshop on Metrology for AeroSpace (MetroAeroSpace)
This paper discusses the possible non-destructive testing (NDT) techniques for a novel bonding qu... more This paper discusses the possible non-destructive testing (NDT) techniques for a novel bonding quality evaluation technique based on comparison of different inspection methodologies. The goal of this paper is to guide a way for bonding quality evaluation with high reliability by comparing different NDT techniques including ultrasonic, electromagnetic, and thermography. The advantages and limitations of each different NDT technique have been reported systematically. Two case studies have been investigated with two different NDT techniques, namely ultrasonic and induction thermography. The results suggested the limitations and advantages of NDT techniques. In order to compensate the limitations of each technique, data fusion of the selected techniques is proposed.
The European Physical Journal Applied Physics, 2016
Using a 3D finite elements simulation tool, a study on the flaw detection capacity of the non des... more Using a 3D finite elements simulation tool, a study on the flaw detection capacity of the non destructive testing (NDT) induction thermography (IT) technique for laminated carbon fiber reinforced polymers (CFRP) composites is presented. Delamination and fiber rupture flaw occurring at the elementary-ply scale are considered. In order to reduce the impact of measurement noise on the flaw detectability, several signal processing techniques are proposed.
International Journal of Electronics, Apr 23, 2007
ABSTRACT Simulated annealing (SA) adapted to continuous variables is used lo determine the synapt... more ABSTRACT Simulated annealing (SA) adapted to continuous variables is used lo determine the synaptic coefficients of an analogue multilayer neural network, approximating any continuous function of one or several variables. The ‘open’ electrical simulator SPICE-PAC driven by SA produces a globally optimal set of synaptic weights, in a reasonable time and without requiring heavy and inaccurate gradient computations, We illustrate and improve our weights tuning strategy through simple examples.
International Journal of Electronics, Apr 23, 2007
ABSTRACT An efficient new method, based on the coupling between an enhanced simulated annealing a... more ABSTRACT An efficient new method, based on the coupling between an enhanced simulated annealing algorithm and the SPICE-PAC ‘open’ circuit simulator, is proposed for minimizing objective functions describing circuit performance optimization problems or component model fitting to experimental data. To keep the number of objective function evaluations and CPU times to the lowest possible level, we focus our attention on two features: first, we build an original partitioning technique for splitting large n-dimensional problems; then we carefully study variables discretization, (which is necessary for applying the simulated annealing method to continuous problems). To illustrate the efficiency of our method, we show how to determine the 40 MOS transistor model parameters, through fitting the model to experimental data.
This work mainly deals with the characterization of the delaminations in the fibre-metal laminate... more This work mainly deals with the characterization of the delaminations in the fibre-metal laminates as the Glare®. We present a direct model based on Electromagnetic Coupled Circuit Method (ECCM). This model has been improved and coupled with analytical computations to avoid the discretization of the load. The number of unknowns needed for obtaining the sensor impedance variations is reduced and computation of the direct model has been sped up. Thus, an optimization algorithm could be applied to obtain the material physical properties and the delamination geometrical parameters in multilayer materials. The particle swarm optimization (PSO), a recent powerful optimization technique, is then coupled with the direct model in an inversion process, providing the desired parameters. Some examples, linked to aeronautics, are presented: thickness of layers and delamination geometrical characterization in fiber-metal laminate material as Glare®. Experimental results are shown and analyzed in ...
A semi-analytical forward model based on the electromagnetic coupled cir-cuits method is presente... more A semi-analytical forward model based on the electromagnetic coupled cir-cuits method is presented. This model allows to simulate the impedance variation of a ferrite-cored sensor above a controlled material. The computational speed is increased by determinig the current density in coil using the Kelvin analytical distribution. This forward model provides a good accuracy with respect to experimental measurements. 1 Main objectives ECNDT is generally used in such frequency domain that intrinsic skin and proximity effects of the sensor are rather important (freq. between 100Hz and some MHz). Most of well-used models don't consider these effects which can change considerably the impedance of the sensor. In this paper, we propose a semi-analytical forward model which takes into account these phenomena [1, 4]. Our axisymmetrical model is based on the electromagnetic coupled circuits method (ECCM) [2, 3] which allows to determine the sensor impedance. As this model is fast-running, we...
Modélisation et simulation pour l'analyse et l'optimisation des systèmes industriels et l... more Modélisation et simulation pour l'analyse et l'optimisation des systèmes industriels et logistiques" MOSIM'04 – du 1 er au 3 septembre 2004 -Nantes (France) RÉSUMÉ : Cet article décrit la conception d'une Machine à Réluctance Variable (MRV) basse vitesse destinée à des applications éolienne. On s'intéresse particulièrement à la modélisation et au dimensionnement de la structure de la machine en optimisant d'une part le couple et d'autre part le couple massique. Les dimensions sont obtenues en utilisant un algorithme génétique couplé avec la méthode des éléments finis pour la résolution des équations électromagnétique. . simple refroidir. autonome. L'objectif est d'optimiser la structure de la MOTS-CLÉS : Machine à Réluctance Variable, Optimisation, Algorithme génétique, Eolienne.
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Papers by G. Berthiau