https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Thu, 12 Mar 2026 23:28:41 GMT 2026-03-12T23:28:41Z http://hdl.handle.net/10985/19615 Damage imaging post processing for delamination size assessment of CFRP aeronautic structures BRIAND, William; MECHBAL, Nazih; GUSKOV, Mikhail; RÉBILLAT, Marc Thanks to their high strength to mass ratio, composite materials are now widespread in the aerospace industry. Nevertheless, this type of material is sub- ject to internal damages like delamination. In order to detect and localize these damages, robust and precise Structural Health Monitoring algorithms exist for this purpose and have been validated experimentally. However, in order to avoid struc- tures catastrophic failures and to estimate their residual life, there is still a huge need of reliable damage size assessment methods. In this paper, a damage quanti cation method is proposed. This strategy is based on the extraction of a damage size sen- sitive feature computed from damage imaging results. Here damage imaging stands for methods that use ultrasonic Lamb waves-based map of damage localization like- lihood index. This feature is extracted from each labelled example of a training set in order to infer a mathematical model used to predict the area of a delamination of unknown damages. The proposed method is successfully validated on experimental data carried out on CFRP plate samples equipped with a piezoelectric transducers network. Wed, 01 Jan 2020 00:00:00 GMT http://hdl.handle.net/10985/19615 2020-01-01T00:00:00Z BRIAND, William MECHBAL, Nazih GUSKOV, Mikhail RÉBILLAT, Marc Thanks to their high strength to mass ratio, composite materials are now widespread in the aerospace industry. Nevertheless, this type of material is sub- ject to internal damages like delamination. In order to detect and localize these damages, robust and precise Structural Health Monitoring algorithms exist for this purpose and have been validated experimentally. However, in order to avoid struc- tures catastrophic failures and to estimate their residual life, there is still a huge need of reliable damage size assessment methods. In this paper, a damage quanti cation method is proposed. This strategy is based on the extraction of a damage size sen- sitive feature computed from damage imaging results. Here damage imaging stands for methods that use ultrasonic Lamb waves-based map of damage localization like- lihood index. This feature is extracted from each labelled example of a training set in order to infer a mathematical model used to predict the area of a delamination of unknown damages. The proposed method is successfully validated on experimental data carried out on CFRP plate samples equipped with a piezoelectric transducers network. http://hdl.handle.net/10985/23351 Fusion of SHM techniques for synergetic degradation monitoring of composite aircraft wing structure under compression fatigue YUE, Nan; BROER, Agnes; GALANOPOULOS, Georgios; BRIAND, William; RÉBILLAT, Marc; LOUTAS, Theodoros; ZAROUCHAS, Dimitrios In the pursue of smart structures for cyber-physical health management of lightweight engineering structures, a number of structural health monitoring methods have been developed. Each SHM technique has different coverage and sensitivity to certain types of damage. In particular, the structural degradation of composites under fatigue loading is multi-causal and intricate, and none of the techniques alone is able to fully capture the fatigue degradation phenomenon. This paper presents the considerations and results in a fusing strategy of two different SHM techniques, distributed optical strain sensing and guided wave, on the in-situ monitoring of an aircraft wing structure under compression-compression fatigue loading. The emergence and growth of localized damage (disbond of stiffener foot) and the degradation of mechanical performance (stiffness degradation) caused by the accumulation of distributed fatigue damage have been monitored in the synergy of the two different SHM techniques. The result shows that the fusion strategy unveils the fatigue degradation phenomenon in a more extensive manner than using two techniques separately. Sun, 01 May 2022 00:00:00 GMT http://hdl.handle.net/10985/23351 2022-05-01T00:00:00Z YUE, Nan BROER, Agnes GALANOPOULOS, Georgios BRIAND, William RÉBILLAT, Marc LOUTAS, Theodoros ZAROUCHAS, Dimitrios In the pursue of smart structures for cyber-physical health management of lightweight engineering structures, a number of structural health monitoring methods have been developed. Each SHM technique has different coverage and sensitivity to certain types of damage. In particular, the structural degradation of composites under fatigue loading is multi-causal and intricate, and none of the techniques alone is able to fully capture the fatigue degradation phenomenon. This paper presents the considerations and results in a fusing strategy of two different SHM techniques, distributed optical strain sensing and guided wave, on the in-situ monitoring of an aircraft wing structure under compression-compression fatigue loading. The emergence and growth of localized damage (disbond of stiffener foot) and the degradation of mechanical performance (stiffness degradation) caused by the accumulation of distributed fatigue damage have been monitored in the synergy of the two different SHM techniques. The result shows that the fusion strategy unveils the fatigue degradation phenomenon in a more extensive manner than using two techniques separately. http://hdl.handle.net/10985/23349 Damage Size Quantification Using Lamb Waves by Analytical Model Identification BRIAND, William; RÉBILLAT, Marc; GUSKOV, Mikhail; MECHBAL, Nazih Corrosion is a major concern for the aeronautic industry and providing structures with the intrinsic ability to monitor autonomously their health state is a major actual academic and industrial challenge. In this paper, detection, localization, and quantification of a damage representative of a corrosion damage using Lamb waves emitted and received by piezoelectric elements for the purpose of structural health monitoring of aeronautics aluminum structures is addressed. Semi-spherical holes of differ- ent sizes representing a calibrated corrosion pit are manufactured on a 2024 aluminum plate with four piezoelectric sensors bonded on it. Lamb waves are then recorded with one element used as an actuator and the other ones being used as sensors. A dedicated recording system provided by Cedrat Technologies is used to acquire Lamb waves data. It is demonstrated on this representative example that by using actual algorithms from the SHM literature, it is possible to detect, localize, and quantify this damage representative of an actual corrosion damage. These preliminary results are very encouraging before monitoring actual corrosion and fatigue damages which constitutes the main objective of the COQTEL project. Wed, 01 Jun 2022 00:00:00 GMT http://hdl.handle.net/10985/23349 2022-06-01T00:00:00Z BRIAND, William RÉBILLAT, Marc GUSKOV, Mikhail MECHBAL, Nazih Corrosion is a major concern for the aeronautic industry and providing structures with the intrinsic ability to monitor autonomously their health state is a major actual academic and industrial challenge. In this paper, detection, localization, and quantification of a damage representative of a corrosion damage using Lamb waves emitted and received by piezoelectric elements for the purpose of structural health monitoring of aeronautics aluminum structures is addressed. Semi-spherical holes of differ- ent sizes representing a calibrated corrosion pit are manufactured on a 2024 aluminum plate with four piezoelectric sensors bonded on it. Lamb waves are then recorded with one element used as an actuator and the other ones being used as sensors. A dedicated recording system provided by Cedrat Technologies is used to acquire Lamb waves data. It is demonstrated on this representative example that by using actual algorithms from the SHM literature, it is possible to detect, localize, and quantify this damage representative of an actual corrosion damage. These preliminary results are very encouraging before monitoring actual corrosion and fatigue damages which constitutes the main objective of the COQTEL project. http://hdl.handle.net/10985/23345 Detection, localization, and quantification of corrosion damage using Lamb Waves for the structural health monitoring of aluminum aeronautics structures LIEGEY, Julie; BRIAND, William; RÉBILLAT, Marc; EL MAY, Mohamed; DEVOS, Olivier; MECHBAL, Nazih Corrosion is a major concern for the aeronautic industry and providing structures with the intrinsic ability to monitor autonomously their health state is a major actual academic and industrial challenge. In this paper, detection, localization, and quantification of a damage representative of a corrosion damage using Lamb waves emitted and received by piezoelectric elements for the purpose of structural health monitoring of aeronautics aluminum structures is addressed. Semi-spherical holes of different sizes representing a calibrated corrosion pit are manufactured on a 2024 aluminum plate with four piezoelectric sensors bonded on it. Lamb waves are then recorded with one element used as an actuator and the other ones being used as sensors. A dedicated recording system provided by Cedrat Technologies is used to acquire Lamb waves data. It is demonstrated on this representative example that by using actual algorithms from the SHM literature, it is possible to detect, localize, and quantify this damage representative of an actual corrosion damage. These preliminary results are very encouraging before monitoring actual corrosion and fatigue damages which constitutes the main objective of the COQTEL project. Mon, 04 Jul 2022 00:00:00 GMT http://hdl.handle.net/10985/23345 2022-07-04T00:00:00Z LIEGEY, Julie BRIAND, William RÉBILLAT, Marc EL MAY, Mohamed DEVOS, Olivier MECHBAL, Nazih Corrosion is a major concern for the aeronautic industry and providing structures with the intrinsic ability to monitor autonomously their health state is a major actual academic and industrial challenge. In this paper, detection, localization, and quantification of a damage representative of a corrosion damage using Lamb waves emitted and received by piezoelectric elements for the purpose of structural health monitoring of aeronautics aluminum structures is addressed. Semi-spherical holes of different sizes representing a calibrated corrosion pit are manufactured on a 2024 aluminum plate with four piezoelectric sensors bonded on it. Lamb waves are then recorded with one element used as an actuator and the other ones being used as sensors. A dedicated recording system provided by Cedrat Technologies is used to acquire Lamb waves data. It is demonstrated on this representative example that by using actual algorithms from the SHM literature, it is possible to detect, localize, and quantify this damage representative of an actual corrosion damage. These preliminary results are very encouraging before monitoring actual corrosion and fatigue damages which constitutes the main objective of the COQTEL project. http://hdl.handle.net/10985/19519 DAMAGE SIZE QUANTIFICATION IN AERONAUTIC COMPOSITE STRUCTURES BASED ON IMAGING RESULTS POST-PROCESSING BRIAND, William; MECHBAL, Nazih; GUSKOV, Mikhail; RÉBILLAT, Marc Thanks to their high strength to mass ratio, composite materials are now widespread in the aerospace industry. Nevertheless, this type of material is subject to various internal damages and it is mandatory to monitor in real time their structural integrity. Structural Health Monitoring (SHM) is a process based on embedded sensors whose aim is to detect, locate, classify and quantify potential damages appearing in a structure in order to avoid structures catastrophic failures and to estimate their residual life. The most widely used technique to perform SHM of aeronautical structures made up of composite materials is based on the use of ultrasonic Lamb waves. However, even if robust and precise SHM algorithms exist for damage detection and localization, there is still a huge need for reliable algorithms for damage quantification. In this paper, a damage quantification strategy based on a post-processing step of the results of damage imaging method is presented. Such a method allows for damage size assessment of a delaminated area by post-processing the images produced by damage localization algorithms. Localization methods take raw signals from sensor as input and return a map of index representing the likelihood of presence of a damage over the surface of the structure under study. From this spatial probability map, region of high localization index can be identified around the estimated damage location and the area this region can be computed. A data-driven model representing the mathematical relationship between the computed area and the actual size of the damage is then inferred. The proposed method is successfully validated on numerical simulation data carried out on CFRP plate samples equipped with a stiffener and of a piezoelectric sensor-actuator network with several configurations of damage size. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/19519 2019-01-01T00:00:00Z BRIAND, William MECHBAL, Nazih GUSKOV, Mikhail RÉBILLAT, Marc Thanks to their high strength to mass ratio, composite materials are now widespread in the aerospace industry. Nevertheless, this type of material is subject to various internal damages and it is mandatory to monitor in real time their structural integrity. Structural Health Monitoring (SHM) is a process based on embedded sensors whose aim is to detect, locate, classify and quantify potential damages appearing in a structure in order to avoid structures catastrophic failures and to estimate their residual life. The most widely used technique to perform SHM of aeronautical structures made up of composite materials is based on the use of ultrasonic Lamb waves. However, even if robust and precise SHM algorithms exist for damage detection and localization, there is still a huge need for reliable algorithms for damage quantification. In this paper, a damage quantification strategy based on a post-processing step of the results of damage imaging method is presented. Such a method allows for damage size assessment of a delaminated area by post-processing the images produced by damage localization algorithms. Localization methods take raw signals from sensor as input and return a map of index representing the likelihood of presence of a damage over the surface of the structure under study. From this spatial probability map, region of high localization index can be identified around the estimated damage location and the area this region can be computed. A data-driven model representing the mathematical relationship between the computed area and the actual size of the damage is then inferred. The proposed method is successfully validated on numerical simulation data carried out on CFRP plate samples equipped with a stiffener and of a piezoelectric sensor-actuator network with several configurations of damage size. http://hdl.handle.net/10985/20415 Upcoming damage size quantification in aeronautic composite structures based on imaging results post-processing BRIAND, William; RÉBILLAT, Marc; GUSKOV, Mikhail; MECHBAL, Nazih In this paper, a damage quantification strategy relying on post-processing of Lamb wave based damage localization results is presented. This method is able to predict the upcoming sizes of a delamination after a training step. Inputs of the proposed method are localization index maps produced by damage localization algorithms and representing the presence likelihood of a damage over the structure under study. The area covered by a high localization index around the estimated damage location are then extracted from these spatial probability maps. A data-driven model representing the mathematical relationship between this quantification feature and the actual size of the damage is finally inferred and used to predict future damage size. The proposed method is successfully validated on experimental data coming from CFRP plate samples equipped with piezoelectric transducers. Delaminations induced by fatigue testing and laser shock are studied. The sensitivity of the method to input frequency and damage localization algorithms parameters is assessed and a method to automatically select its own parameters is proposed. Furthermore, it is demonstrated that a model can be confidently learned on a given CFRP plate sample and transferred to predict damage size on another similar CFRP plate sample. Fri, 01 Jan 2021 00:00:00 GMT http://hdl.handle.net/10985/20415 2021-01-01T00:00:00Z BRIAND, William RÉBILLAT, Marc GUSKOV, Mikhail MECHBAL, Nazih In this paper, a damage quantification strategy relying on post-processing of Lamb wave based damage localization results is presented. This method is able to predict the upcoming sizes of a delamination after a training step. Inputs of the proposed method are localization index maps produced by damage localization algorithms and representing the presence likelihood of a damage over the structure under study. The area covered by a high localization index around the estimated damage location are then extracted from these spatial probability maps. A data-driven model representing the mathematical relationship between this quantification feature and the actual size of the damage is finally inferred and used to predict future damage size. The proposed method is successfully validated on experimental data coming from CFRP plate samples equipped with piezoelectric transducers. Delaminations induced by fatigue testing and laser shock are studied. The sensitivity of the method to input frequency and damage localization algorithms parameters is assessed and a method to automatically select its own parameters is proposed. Furthermore, it is demonstrated that a model can be confidently learned on a given CFRP plate sample and transferred to predict damage size on another similar CFRP plate sample. http://hdl.handle.net/10985/21955 Assessing stiffness degradation of stiffened composite panels in post-buckling compression-compression fatigue using guided waves YUE, Nan; BROER, Agnes; BRIAND, William; RÉBILLAT, Marc; LOUTAS, Theodoros; ZAROUCHAS, Dimitrios The application of structural health monitoring (SHM) in composite airframe structural elements under long- term realistic fatigue loading needs to consider the structural behavior on the global level, which is an intri- cate task. The overall structural stiffness is a key design parameter for composite structures and the stiffness degradation under fatigue loading is closely related to the damage accumulation and failure mechanism which can be used as an indicator for the structural degradation. Therefore, this paper investigates the use of guided waves in axial stiffness degradation estimation for stiffened carbon fiber reinforced polymer (CFRP) composite panels under post-buckling compression-compression (C-C) fatigue loads. Impacted or artificially debonded stiffened composite panels are tested under fatigue until failure and guided waves are acquired using a network of piezoelectric (PZT) sensors at fixed cycle intervals. The guided wave phase velocity along the loading direction is extracted to estimate the axial stiffness degradation with the consideration of mode conversion and failure of PZT sensors. The estimated stiffness of five stiffened composite panels matches well with the stiffness calculated from the load–displacement curves. The estimated stiffness is also assessed using prognostic performance metrics and shows good potential for being used as a health indicator for prognostic purposes. Mon, 01 Aug 2022 00:00:00 GMT http://hdl.handle.net/10985/21955 2022-08-01T00:00:00Z YUE, Nan BROER, Agnes BRIAND, William RÉBILLAT, Marc LOUTAS, Theodoros ZAROUCHAS, Dimitrios The application of structural health monitoring (SHM) in composite airframe structural elements under long- term realistic fatigue loading needs to consider the structural behavior on the global level, which is an intri- cate task. The overall structural stiffness is a key design parameter for composite structures and the stiffness degradation under fatigue loading is closely related to the damage accumulation and failure mechanism which can be used as an indicator for the structural degradation. Therefore, this paper investigates the use of guided waves in axial stiffness degradation estimation for stiffened carbon fiber reinforced polymer (CFRP) composite panels under post-buckling compression-compression (C-C) fatigue loads. Impacted or artificially debonded stiffened composite panels are tested under fatigue until failure and guided waves are acquired using a network of piezoelectric (PZT) sensors at fixed cycle intervals. The guided wave phase velocity along the loading direction is extracted to estimate the axial stiffness degradation with the consideration of mode conversion and failure of PZT sensors. The estimated stiffness of five stiffened composite panels matches well with the stiffness calculated from the load–displacement curves. The estimated stiffness is also assessed using prognostic performance metrics and shows good potential for being used as a health indicator for prognostic purposes. http://hdl.handle.net/10985/23350 Lamb waves scattering model for identification of damage parameters BRIAND, William; RÉBILLAT, Marc; GUSKOV, Mikhail; MECHBAL, Nazih In order to optimize their maintenance costs, airlines are very interested in the condition based maintenance approach. For this purpose, structural health data coming from the monitoring of structural subcomponents and in particular their residual useful life (RUL) are used. If a damage is detected in the part, the evolution of its size will strongly influence the RUL. It is therefore essential to have a tool to monitor the size of defects in structures in a reliable manner. In this article, we propose an analytical scattering model that deals with piezoelectric transducers in acting and sensing mode. The actuator generates Lamb waves which are reflected by an inhomogeneity in the material and captured by the PZT in sensor mode. By specifying the material parameters and the input signal, the model predicts the output signal. The theoretical model is successfully validated on simulation data. Finally, the model is used to perform damage size quantification. Sun, 01 May 2022 00:00:00 GMT http://hdl.handle.net/10985/23350 2022-05-01T00:00:00Z BRIAND, William RÉBILLAT, Marc GUSKOV, Mikhail MECHBAL, Nazih In order to optimize their maintenance costs, airlines are very interested in the condition based maintenance approach. For this purpose, structural health data coming from the monitoring of structural subcomponents and in particular their residual useful life (RUL) are used. If a damage is detected in the part, the evolution of its size will strongly influence the RUL. It is therefore essential to have a tool to monitor the size of defects in structures in a reliable manner. In this article, we propose an analytical scattering model that deals with piezoelectric transducers in acting and sensing mode. The actuator generates Lamb waves which are reflected by an inhomogeneity in the material and captured by the PZT in sensor mode. By specifying the material parameters and the input signal, the model predicts the output signal. The theoretical model is successfully validated on simulation data. Finally, the model is used to perform damage size quantification.