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Papers by Ala Eddine Lakhdari

Research paper thumbnail of Gap Estimation of Disbanding Failure Appears in Hybrid Laminate Material by Means of an Eddy Current Evaluation

2018 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2018

The aim of this paper is to estimate the gap of a disbanding failure appears in the hybrid lamina... more The aim of this paper is to estimate the gap of a disbanding failure appears in the hybrid laminate material by means of the eddy current non-destructive evaluation (EC-NDE) method. In order to model and analyse the corresponding problem, a 3D FVM anisotropic numerical model is developed, in which the heterogeneity of the hybrid laminate material is taken into account. To estimate the gap of a disbanding failure, the developed model is hence inversed using the Nelder-Mead simplex algorithm. Both numerical and experimental results are given in this paper related to an experimental sample of the hybrid material.

Research paper thumbnail of Modélisation d’un Capteur Différentiel de CND-CF par la Méthode des Volumes Finis

Research paper thumbnail of Modélisation en Volumes Finis de CND des Matériaux Faiblement Conducteurs par Courants de Foucault et de Déplacement

Compte tenu de la grande demande des matériaux composites dans différents secteurs de l’industrie... more Compte tenu de la grande demande des matériaux composites dans différents secteurs de l’industrie, notamment l’aéronautique et l’automobile, les méthodes de ses contrôle non destructif et l’évaluation (CND et E) deviennent indispensables, surtout celles qui sont par les courants de Foucault. Par ailleurs, certains problèmes de CND-CF notamment ceux qui liés à la caractérisation des défauts et également la structure en matériaux composites, évoquent des outils de simulations numériques. A cet effet, le travail de cette thèse est consacré au développement d’un modèle de modélisation 3D par la méthode des volumes fins, adapté aux problèmes de CND-CF des matériaux composites. Ce modèle est pris en compte de l’anisotropie du matériau, ainsi que la sollicitation des éléments prismes et la formulation potentiel vecteur magnétique A-V. En outre, afin de valider le code de calcul développé en se basant sur ledit modèle, différentes applications sont considérées, certaines d'entre sont ex...

Research paper thumbnail of FVM model and virtual instrument based system for electromagnetic characterization of steel material

This paper deals with a finite volume model and virtual instrument based system for electromagnet... more This paper deals with a finite volume model and virtual instrument based system for electromagnetic characterization of steel material. Both magnetic permeability and electrical conductivity are electromagnetic properties must be defined. These two parameters are strongly required for electromagnetic problems analysis such as in eddy current nondestructive testing problem. The magnetic permeability is measured by using the B(H) loop of the steel material which is illustrated by experimental measurement through a virtual instrument based system. However, the electrical conductivity is obtained by the solution of an inverse problem. For that reason a direct electromagnetic model is analyzed using the finite volume method.

Research paper thumbnail of Modélisation 3D d’un capteur matriciel à courants de Foucault par la MVF

Research paper thumbnail of Etude et Modelisation De Capteurs en CND Par Courants De Foucault : Application a La Detection Des Fissures

Relativement aux dangers lesquels provenant par la fissuration des structures metalliques: toles,... more Relativement aux dangers lesquels provenant par la fissuration des structures metalliques: toles, tubes… etc., dans le secteur industriel (aviation, automobile, centrale nucleaire), souvent un controle de qualite est exige. Parmi les methodes de controle non destructif les plus en plus utilisees, on trouve la technique de controle non destructif par courants de Foucault CND-CF. Cette technique est basee sur le fait que si un capteur inductif est alimente par un courant variable et apporte a proximite d'une piece conductrice, une variation d'impedance du capteur sera entrainee par la modification des lignes du champ magnetique due a l'existence d'un defaut dans la piece. La methode des volumes finis est une methode tres prometteuse en termes temps de calcul et consommation d’espace memoire. Les travaux traites dans ce memoire concernent la modelisation par la MVF et l’analyse des principaux capteurs utilises dans les systemes de controle non destructif par courants de...

Research paper thumbnail of Estimation of a Hidden Crack Position Using the FVM Skin Effect Analysis

Research paper thumbnail of Accurate measurement of Aluminum layer thickness in a multilayer material using eddy current sensor

2016 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2016

This paper presents an eddy current sensor based system that allows thickness measurement of an A... more This paper presents an eddy current sensor based system that allows thickness measurement of an Aluminum layer in multilayer material. An electromagnetic analytical model is used to give the relationship between the response of the eddy current sensor and the Aluminum layer thickness for different frequencies, and then looking for the optimal working frequency according to a given criterion. The measurement system is performed and controlled by a Labview application in which the analytical relationship is integrated. Some experimental samples of multilayer material containing an Aluminum layer with different thicknesses are used to verify the measurement system. A good accuracy and agreement is observed between the measured thicknesses and the exact thickness of the samples.

Research paper thumbnail of 3D-FVM anisotropic model for eddy current problems related to composite materials

Nondestructive Testing and Evaluation, 2018

In this paper, a 3D-finite volume method model is developed to analyse eddy current problems rela... more In this paper, a 3D-finite volume method model is developed to analyse eddy current problems related to anisotropic conductive materials. Two unidirectional composite materials (boron fibres reinforced aluminium alloy, carbon fibres reinforced polymer) are studied. To be adapted to such problem, the finite volume implementation of the A-V formulation has been carried out by using the unstructured mesh, where the prism shape of the elementary volume is introduced. The effects of the mesh type either prism mesh or hexahedral mesh on the accuracy and the CPU time are carefully analysed. The anisotropy ratio on the eddy current distribution is also discussed. The developed numerical model is validated by comparison to experimental results.

Research paper thumbnail of Transient axisymmetric FVM analysis of electodynamic levitation devices

The European Physical Journal Applied Physics, 2013

In this paper a transient finite volume model for electrodynamic levitation devices analysis has ... more In this paper a transient finite volume model for electrodynamic levitation devices analysis has been developed. Both electromagnetic and mechanical equations are time stepped and coupled to give the dynamic characteristic of the motion. Furthermore, the nonconforming mesh technique is introduced to take movement into account. To check the efficiency and accuracy of the transient finite volume method (FVM) model, the Team Workshop Problem 28 is used.

Research paper thumbnail of Skin effect based technique in eddy current non-destructive testing for thickness measurement of conductive material

IET Science, Measurement & Technology, 2019

This study proposes an estimation procedure for thickness measurement of conductive material by i... more This study proposes an estimation procedure for thickness measurement of conductive material by investigating the skin effect phenomenon in eddy current non-destructive testing. Both three-dimensional numerical modelling using the finite volume method and experimental analysis are considered. Before starting this investigation, the material to be measured must be recognised in terms of its electrical conductivity, and hence this study presents also an electrical conductivity characterisation which is identified by using two methods; the first one is the four-probe-based technique while the second one is an eddy current-based technique.

Research paper thumbnail of Gap Estimation of Disbanding Failure Appears in Hybrid Laminate Material by Means of an Eddy Current Evaluation

2018 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2018

The aim of this paper is to estimate the gap of a disbanding failure appears in the hybrid lamina... more The aim of this paper is to estimate the gap of a disbanding failure appears in the hybrid laminate material by means of the eddy current non-destructive evaluation (EC-NDE) method. In order to model and analyse the corresponding problem, a 3D FVM anisotropic numerical model is developed, in which the heterogeneity of the hybrid laminate material is taken into account. To estimate the gap of a disbanding failure, the developed model is hence inversed using the Nelder-Mead simplex algorithm. Both numerical and experimental results are given in this paper related to an experimental sample of the hybrid material.

Research paper thumbnail of Modélisation d’un Capteur Différentiel de CND-CF par la Méthode des Volumes Finis

Research paper thumbnail of Modélisation en Volumes Finis de CND des Matériaux Faiblement Conducteurs par Courants de Foucault et de Déplacement

Compte tenu de la grande demande des matériaux composites dans différents secteurs de l’industrie... more Compte tenu de la grande demande des matériaux composites dans différents secteurs de l’industrie, notamment l’aéronautique et l’automobile, les méthodes de ses contrôle non destructif et l’évaluation (CND et E) deviennent indispensables, surtout celles qui sont par les courants de Foucault. Par ailleurs, certains problèmes de CND-CF notamment ceux qui liés à la caractérisation des défauts et également la structure en matériaux composites, évoquent des outils de simulations numériques. A cet effet, le travail de cette thèse est consacré au développement d’un modèle de modélisation 3D par la méthode des volumes fins, adapté aux problèmes de CND-CF des matériaux composites. Ce modèle est pris en compte de l’anisotropie du matériau, ainsi que la sollicitation des éléments prismes et la formulation potentiel vecteur magnétique A-V. En outre, afin de valider le code de calcul développé en se basant sur ledit modèle, différentes applications sont considérées, certaines d'entre sont ex...

Research paper thumbnail of FVM model and virtual instrument based system for electromagnetic characterization of steel material

This paper deals with a finite volume model and virtual instrument based system for electromagnet... more This paper deals with a finite volume model and virtual instrument based system for electromagnetic characterization of steel material. Both magnetic permeability and electrical conductivity are electromagnetic properties must be defined. These two parameters are strongly required for electromagnetic problems analysis such as in eddy current nondestructive testing problem. The magnetic permeability is measured by using the B(H) loop of the steel material which is illustrated by experimental measurement through a virtual instrument based system. However, the electrical conductivity is obtained by the solution of an inverse problem. For that reason a direct electromagnetic model is analyzed using the finite volume method.

Research paper thumbnail of Modélisation 3D d’un capteur matriciel à courants de Foucault par la MVF

Research paper thumbnail of Etude et Modelisation De Capteurs en CND Par Courants De Foucault : Application a La Detection Des Fissures

Relativement aux dangers lesquels provenant par la fissuration des structures metalliques: toles,... more Relativement aux dangers lesquels provenant par la fissuration des structures metalliques: toles, tubes… etc., dans le secteur industriel (aviation, automobile, centrale nucleaire), souvent un controle de qualite est exige. Parmi les methodes de controle non destructif les plus en plus utilisees, on trouve la technique de controle non destructif par courants de Foucault CND-CF. Cette technique est basee sur le fait que si un capteur inductif est alimente par un courant variable et apporte a proximite d'une piece conductrice, une variation d'impedance du capteur sera entrainee par la modification des lignes du champ magnetique due a l'existence d'un defaut dans la piece. La methode des volumes finis est une methode tres prometteuse en termes temps de calcul et consommation d’espace memoire. Les travaux traites dans ce memoire concernent la modelisation par la MVF et l’analyse des principaux capteurs utilises dans les systemes de controle non destructif par courants de...

Research paper thumbnail of Estimation of a Hidden Crack Position Using the FVM Skin Effect Analysis

Research paper thumbnail of Accurate measurement of Aluminum layer thickness in a multilayer material using eddy current sensor

2016 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2016

This paper presents an eddy current sensor based system that allows thickness measurement of an A... more This paper presents an eddy current sensor based system that allows thickness measurement of an Aluminum layer in multilayer material. An electromagnetic analytical model is used to give the relationship between the response of the eddy current sensor and the Aluminum layer thickness for different frequencies, and then looking for the optimal working frequency according to a given criterion. The measurement system is performed and controlled by a Labview application in which the analytical relationship is integrated. Some experimental samples of multilayer material containing an Aluminum layer with different thicknesses are used to verify the measurement system. A good accuracy and agreement is observed between the measured thicknesses and the exact thickness of the samples.

Research paper thumbnail of 3D-FVM anisotropic model for eddy current problems related to composite materials

Nondestructive Testing and Evaluation, 2018

In this paper, a 3D-finite volume method model is developed to analyse eddy current problems rela... more In this paper, a 3D-finite volume method model is developed to analyse eddy current problems related to anisotropic conductive materials. Two unidirectional composite materials (boron fibres reinforced aluminium alloy, carbon fibres reinforced polymer) are studied. To be adapted to such problem, the finite volume implementation of the A-V formulation has been carried out by using the unstructured mesh, where the prism shape of the elementary volume is introduced. The effects of the mesh type either prism mesh or hexahedral mesh on the accuracy and the CPU time are carefully analysed. The anisotropy ratio on the eddy current distribution is also discussed. The developed numerical model is validated by comparison to experimental results.

Research paper thumbnail of Transient axisymmetric FVM analysis of electodynamic levitation devices

The European Physical Journal Applied Physics, 2013

In this paper a transient finite volume model for electrodynamic levitation devices analysis has ... more In this paper a transient finite volume model for electrodynamic levitation devices analysis has been developed. Both electromagnetic and mechanical equations are time stepped and coupled to give the dynamic characteristic of the motion. Furthermore, the nonconforming mesh technique is introduced to take movement into account. To check the efficiency and accuracy of the transient finite volume method (FVM) model, the Team Workshop Problem 28 is used.

Research paper thumbnail of Skin effect based technique in eddy current non-destructive testing for thickness measurement of conductive material

IET Science, Measurement & Technology, 2019

This study proposes an estimation procedure for thickness measurement of conductive material by i... more This study proposes an estimation procedure for thickness measurement of conductive material by investigating the skin effect phenomenon in eddy current non-destructive testing. Both three-dimensional numerical modelling using the finite volume method and experimental analysis are considered. Before starting this investigation, the material to be measured must be recognised in terms of its electrical conductivity, and hence this study presents also an electrical conductivity characterisation which is identified by using two methods; the first one is the four-probe-based technique while the second one is an eddy current-based technique.