Professor Joseph MOYSAN graduated from the Mechanical Engineering school ECAM Lyon in 1989 and obtained his PhD from INSA Lyon in 1992 (FRANCE). He is now a full professor at Aix-Marseille University in the Mechanical Engineering Department of the Institute of Technology in Aix en Provence.He began research and teaching in NDT in 1993. He won the Gold Medal for the European NDT Innovation Awards in 1994 for his work concerning the automatic thresholding of ultrasound images. He developed NDT analysis for metallic welds (defects detection, grain noise analysis) and contributed to the development of the MINA model that describes weld microstructure at the ultrasonic scale. He is also interested in the development of NDT solutions for nuclear reactors since year 2001 and directed several PHD thesis in this domain. He also recently managed an extensive French program to develop innovative NDT solutions to evaluate nondestructive bond strength (ISABEAU). He is a member of the permanent scientific council for the French NDT association (COFREND) since 2015.
In some polycrystalline materials, ultrasonic non destructive testing is affected by structural n... more In some polycrystalline materials, ultrasonic non destructive testing is affected by structural noise and attenuation. Those phenomena can cause significant loss in detection performances, thus their prediction is of great practical interest. During previous works at CEA-LIST, noise and attenuation models have been developed and implemented into the simulation software for non destructive testing CIVA. These two models are based
The presence of microscopic gas pockets trapped on a non-wetting solid/liquid interface induces a... more The presence of microscopic gas pockets trapped on a non-wetting solid/liquid interface induces a significant decrease of the transmitted ultrasonic energy. This phenomenon can reduce the performance of ultrasonic inspection in sodium-cooled fast reactors (SFR) for instance. To explain this event, a hypothesis was formulated in a previous study: under the effect of ultrasound, the gas pockets could coalesce, forming a gas film which would prevent the passage of the ultrasound. This coalescence hypothesis can be studied by visual observation of the phenomenon. This paper is presenting an original experiment which simulates this phenomenon in water. This experiment consists in observing the ultrasound-induced behaviour of gas pockets over various time scales. The results allow dismissing the coalescence hypothesis. Our conclusion indicates how future works are reoriented to improve the design of ultrasonic transducers dedicated to SFR inspection.
ABSTRACT The inspection of austenitic welds used in the nuclear field with ultrasound involves pr... more ABSTRACT The inspection of austenitic welds used in the nuclear field with ultrasound involves problems of interpretation: intense grain noise makes the detection of the crack difficult. The formation B-scan images and their digital processing increase the effectiveness of testing. A segmentation method based on the cooccurrence matrix is presented. It separates defect zones and noise zones. The calculation of statistical parameters makes it possible to automate and to improve image thresholding. Defect sizing through the analysis of the modified image is the final goal. Some examples of segmentation improvement applied to artificial defects are presented
This paper presents a generalization to eddy current images of a thresholding method developed fo... more This paper presents a generalization to eddy current images of a thresholding method developed for ultrasonic imaging. It is also shown how to improve the thresholding strength through the definition of a cooperation rule between two threshold assessment measures. This rule is also used to reduce time of calculus. These measures are calculated from the image cooccurrence matrix. The aim
... in NDT. We solve for the vector d through an automatic analysis of the matrix behaviour for s... more ... in NDT. We solve for the vector d through an automatic analysis of the matrix behaviour for several vectors based on the characteriz ation curves. The developed method allows us to present an efficient thresholding algorithm that is tested on real images. Image processing ...
... is mainly a twodimensional histogram which multiplies the possibility and the accuracy of ima... more ... is mainly a twodimensional histogram which multiplies the possibility and the accuracy of image analysis. ... Data acquisition The segmentation method is tested on images of defects fabricated by electroerosion in stainless steel plates which have an austenitic weld. ...
ABSTRACT To increase the reliability of non-destructive examinations of plasma facing components ... more ABSTRACT To increase the reliability of non-destructive examinations of plasma facing components (PFC), we present steps in order to make data combination in this study. The industrial issue is the inspection of manufacturing quality of these components which must support a very high-heat flux in Tokamaks. The experimental study was conducted on trial components for the Wendelstein 7X stellarator using two benches of infrared thermal imaging equipment. The first bench measures the surface temperature with an internal excitation of the components. The second bench uses a lock-in thermal imaging method. The data fusion method makes use of the Dempster–Shaffer theory of evidence. We show that we can improve the decision making for the quality diagnostic. This study could be generalized to other combinations of non-destructive tests for current Tokamaks or those under development like the future ITER reactor.
ABSTRACT The topic of ultrasonic evaluation of bonded joint quality is of interest in many fields... more ABSTRACT The topic of ultrasonic evaluation of bonded joint quality is of interest in many fields such as aeronautics, civil engineering, nuclear industry... The main issue is to determine if the adhesive joint is "good" or not. Up to date, nobody is able to discern an adhesive from a cohesive joint before fracture. As an example, 10 samples prepared in the same time and same conditions (rougthness, cleaning agent, temperature, humidity...) won't have the same mechanical behaviour. 9 will fail at the presumed load, but one will break before. This study is aimed at exploring potentialities of Time Of Flight Modulation to discern an eventual change in the nonlinear signature of an aluminium/epoxy interface.
In some polycrystalline materials, ultrasonic non destructive testing is affected by structural n... more In some polycrystalline materials, ultrasonic non destructive testing is affected by structural noise and attenuation. Those phenomena can cause significant loss in detection performances, thus their prediction is of great practical interest. During previous works at CEA-LIST, noise and attenuation models have been developed and implemented into the simulation software for non destructive testing CIVA. These two models are based
The presence of microscopic gas pockets trapped on a non-wetting solid/liquid interface induces a... more The presence of microscopic gas pockets trapped on a non-wetting solid/liquid interface induces a significant decrease of the transmitted ultrasonic energy. This phenomenon can reduce the performance of ultrasonic inspection in sodium-cooled fast reactors (SFR) for instance. To explain this event, a hypothesis was formulated in a previous study: under the effect of ultrasound, the gas pockets could coalesce, forming a gas film which would prevent the passage of the ultrasound. This coalescence hypothesis can be studied by visual observation of the phenomenon. This paper is presenting an original experiment which simulates this phenomenon in water. This experiment consists in observing the ultrasound-induced behaviour of gas pockets over various time scales. The results allow dismissing the coalescence hypothesis. Our conclusion indicates how future works are reoriented to improve the design of ultrasonic transducers dedicated to SFR inspection.
ABSTRACT The inspection of austenitic welds used in the nuclear field with ultrasound involves pr... more ABSTRACT The inspection of austenitic welds used in the nuclear field with ultrasound involves problems of interpretation: intense grain noise makes the detection of the crack difficult. The formation B-scan images and their digital processing increase the effectiveness of testing. A segmentation method based on the cooccurrence matrix is presented. It separates defect zones and noise zones. The calculation of statistical parameters makes it possible to automate and to improve image thresholding. Defect sizing through the analysis of the modified image is the final goal. Some examples of segmentation improvement applied to artificial defects are presented
This paper presents a generalization to eddy current images of a thresholding method developed fo... more This paper presents a generalization to eddy current images of a thresholding method developed for ultrasonic imaging. It is also shown how to improve the thresholding strength through the definition of a cooperation rule between two threshold assessment measures. This rule is also used to reduce time of calculus. These measures are calculated from the image cooccurrence matrix. The aim
... in NDT. We solve for the vector d through an automatic analysis of the matrix behaviour for s... more ... in NDT. We solve for the vector d through an automatic analysis of the matrix behaviour for several vectors based on the characteriz ation curves. The developed method allows us to present an efficient thresholding algorithm that is tested on real images. Image processing ...
... is mainly a twodimensional histogram which multiplies the possibility and the accuracy of ima... more ... is mainly a twodimensional histogram which multiplies the possibility and the accuracy of image analysis. ... Data acquisition The segmentation method is tested on images of defects fabricated by electroerosion in stainless steel plates which have an austenitic weld. ...
ABSTRACT To increase the reliability of non-destructive examinations of plasma facing components ... more ABSTRACT To increase the reliability of non-destructive examinations of plasma facing components (PFC), we present steps in order to make data combination in this study. The industrial issue is the inspection of manufacturing quality of these components which must support a very high-heat flux in Tokamaks. The experimental study was conducted on trial components for the Wendelstein 7X stellarator using two benches of infrared thermal imaging equipment. The first bench measures the surface temperature with an internal excitation of the components. The second bench uses a lock-in thermal imaging method. The data fusion method makes use of the Dempster–Shaffer theory of evidence. We show that we can improve the decision making for the quality diagnostic. This study could be generalized to other combinations of non-destructive tests for current Tokamaks or those under development like the future ITER reactor.
ABSTRACT The topic of ultrasonic evaluation of bonded joint quality is of interest in many fields... more ABSTRACT The topic of ultrasonic evaluation of bonded joint quality is of interest in many fields such as aeronautics, civil engineering, nuclear industry... The main issue is to determine if the adhesive joint is "good" or not. Up to date, nobody is able to discern an adhesive from a cohesive joint before fracture. As an example, 10 samples prepared in the same time and same conditions (rougthness, cleaning agent, temperature, humidity...) won't have the same mechanical behaviour. 9 will fail at the presumed load, but one will break before. This study is aimed at exploring potentialities of Time Of Flight Modulation to discern an eventual change in the nonlinear signature of an aluminium/epoxy interface.
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Papers by Joseph Moysan