Дисертації з теми "Contrôles structuraux"
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Ayt, Ougougdal Mohamed. "Contrôles magmatiques, structuraux et hydrothermaux de la formation des épisyénites de la marche occidentale." Vandoeuvre-les-Nancy, INPL, 1994. http://docnum.univ-lorraine.fr/public/INPL_T_1994_AYT_OUGOUGDAL_M.pdf.
Chantal-Espinasse, Catherine. "Les minéralisations stratiformes (pyrite, blende) du Cambrien des Malines (Gard, France) : contrôles lithostratigraphiques et structuraux." Montpellier 2, 1987. http://www.theses.fr/1987MON20280.
Salles, Lise. "Contrôles structuraux en 3 dimensions de la sédimentation turbiditique dans les chaînes plissées : exemple des Grès d’Annot (SE de la France)." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL024N/document.
The Annot Sandstone, exposed in the southern sub-alpine chains, consists of sand-rich turbidites deposited in the Tertiary Alpine foreland basin (Upper Eocene – Lower Oligocene Annot Sandstone basin). While the sedimentology and stratigraphy of this turbidite system have been largely described and discussed, its structural framework remains unconstrained. This thesis presents a study of the tectonics of the Annot Sandstone basin based on field surveys and 3D geometrical (gOcad) and kinematic modelling (Trishear), focusing in particular on the Annot, Grand Coyer and Sanguinière sub-basins. Objectives were to determine the structural evolution of the sub-basins, including the role of inherited features, and to use these data to better constrain the alpine tectonic history of SE France.Infill of the early alpine foreland basin is more complex than a simple foreland migration of sedimentation and deformation. Results reveal complex interactions of tectonics and sedimentation at different scales during deposition of the Annot Sandstone.•At the foreland scale, a balanced cross-section illustrates the critical control by the pre-existing salt-based passive margin architecture on the structure of the fold and thrust belt. Triassic evaporates regionally acted as a weak basal detachment, accommodating an early alpine deformation phase of the whole foreland from the Middle to Upper Eocene. Variations in mechanical stratigraphy within the Mesozoic sediments generated a change in structural style. For example, the eastern region is characterized by a thinner, shalier Mesozoic succession, leading to several active detachments during alpine compression. Multiple fold wavelengths and synsedimentary rolling hinges generated by these active detachments led to complex depocentres. The previously under-estimated structural heritage of the foreland basin derived from rifting and spreading of the Alpine Tethys and from an early regional deformation responsible for E-W trending folds, which began in the Late Cretaceous and increased during the Middle Eocene. Preliminary thermochronology results (U-Th/He datings on detrital zircons of medium to coarse sandstone blocks and granodiorite blocks from debris flows of the Sanguiniere depocentre) suggest an exhumation of source areas during this Cretaceous deformation.•A detailed study of structures within the Annot and Grand Coyer sub-basins and their Cretaceous substrate revealed connected depocentres evolving in 3D at the basin scale. Paleocurrent directions are mainly parallel to the main alpine fold axes recording structural confinement, while some diverging directions indicate flow interaction with minor or oblique tectonic features. Turbidites were deposited along the axis into several alpine synclines, which were simultaneously or successively active.•Concerning the depocentre infill, 3D geometrical modelling of the Annot depocentre (using gOcad) was used to identify inherited structures and to constrain alpine fold activity during turbidite deposition. The onlap migration and the specific stacking and dip pattern within turbidite members (laterally rather than vertically stacked deposits) record depocentre migration linked with a rolling synclinal hinge. Due to its sedimentology and its stratigraphy, the Annot Sandstone is well-known as an analogue for sand-rich reservoirs deposited at delta toes in deep-water passive margins. This study reveals that, structurally, it is also a good example of axially-sourced turbidite depocentres developed on a multi-detachement fold and thrust belt
Dentzer, Jacques. "Forçages environnementaux et contrôles structuraux sur le régime thermique actuel du bassin de Paris : enjeux pour la compréhension du potentiel géothermique en Ile-de-France." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066187/document.
The acquisition of measurements of temperature and of thermal conductivity has enriched the understanding of the thermal regime of the Paris sedimentary basin and brought to light spatial and temporal thermal heterogeneities. In order to understand them better, these variations need to be integrated into a multidisciplinary vision of the basin by comparing data against models. The bibliographic review made it possible to integrate data of diverse sorts, to compare them using GIS and to investigate the knowledge base. This study has highlighted and reinterpreted the vertical variations of geothermal flux. Simulations carried out based on diffusive palaeoclimatic scenarios show that the system has retained a memory of the effects of palaeoclimates. Furthermore, for the first time, a systematic decline of the geothermal flux has been identified at the level of the main aquifer formations. Transitory thermo-hydraulic simulations of palaeoclimatic phenomena show the development in the sedimentary basin of cold and hot zones according to the areas of flow. An explanation of the temperature anomaly of over 20°C between the geothermal installations located to the north and south of Paris in the Bathonian is put forward. The models produced clearly show the potential contribution of fractured zones, as well as that of the faults, to the heterogeneity observed in the temperature field of the basin by allowing flow constrained by the regional charge gradient and unstable densities. This work has shown the link between the formations in the basin which are exploited for their resources or used as a storage medium
Dentzer, Jacques. "Forçages environnementaux et contrôles structuraux sur le régime thermique actuel du bassin de Paris : enjeux pour la compréhension du potentiel géothermique en Ile-de-France." Electronic Thesis or Diss., Paris 6, 2016. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2016PA066187.pdf.
The acquisition of measurements of temperature and of thermal conductivity has enriched the understanding of the thermal regime of the Paris sedimentary basin and brought to light spatial and temporal thermal heterogeneities. In order to understand them better, these variations need to be integrated into a multidisciplinary vision of the basin by comparing data against models. The bibliographic review made it possible to integrate data of diverse sorts, to compare them using GIS and to investigate the knowledge base. This study has highlighted and reinterpreted the vertical variations of geothermal flux. Simulations carried out based on diffusive palaeoclimatic scenarios show that the system has retained a memory of the effects of palaeoclimates. Furthermore, for the first time, a systematic decline of the geothermal flux has been identified at the level of the main aquifer formations. Transitory thermo-hydraulic simulations of palaeoclimatic phenomena show the development in the sedimentary basin of cold and hot zones according to the areas of flow. An explanation of the temperature anomaly of over 20°C between the geothermal installations located to the north and south of Paris in the Bathonian is put forward. The models produced clearly show the potential contribution of fractured zones, as well as that of the faults, to the heterogeneity observed in the temperature field of the basin by allowing flow constrained by the regional charge gradient and unstable densities. This work has shown the link between the formations in the basin which are exploited for their resources or used as a storage medium
Oguadinma, Vivian Onyinyechukwu. "The submarine canyon heads of the Niger delta : structural controls, sedimentary infilling and Cenozoic evolution." Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR087.
Submarine canyons are major corridors for transferring sediments from continents to deep submarine basins. Considered transit structures sealed by distal mud, canyons have little perspective in reservoir geology. The source of the sediments, the timing of inputs, and the transport mechanisms in submarine canyons differ from one margin to another depending on the climatic and geodynamic contexts, making it a vast field of study. This work presents the results of a high-resolution 3D seismic survey of a south-eastern submarine canyon in the Niger Delta, the Galabor Canyon. After a literature review, two articles submitted to BSGF are presented in this dissertation. The first article focuses on seismic geomorphology and the relationships between gravity deformation (shale ridges, detachment faults) and canyon dynamics. The seismic volume studied, wedged at the well (gamma ray and biostratigraphic calibration), was explored through (i) vertical sections along and across the thalwegs of the canyon and (ii) seismic attribute maps of key horizons. The confinement of turbiditic flows in intra slope basin bordered by shale ridges explains much of the trapping of sand at the upper slope. Channel processes are responsible for sorting and concentrating sand in meander belts that extend far beyond the initial incision. The second article concerns sequential stratigraphy. Two 100,000-year-old deposition sequences are identified, separated by a dated horizon of 0.99 Ma. In each sequence, the sand is not sourced by an incised valley but by the regressive submarine erosion of shelf-edge deltas. The sand is bypassed in the falling stage system tract, dominated by mass transport deposits, and preserved in the low stand system tract. The transgressive system tract, which is thick and forms an excellent seal above the sandy reservoir, is dominated by fine hemipelagic sedimentation and the high stand system tract is absent. Questions such as sediment source and flow transformations between gravity and tractive mechanisms remain unanswered
Lagarrigue, Olivier. "Contrôle actif structural du rayonnement de plaque." Aix-Marseille 2, 1994. http://www.theses.fr/1994AIX22069.
Yin, Xuming. "Bases neurales de l’apprentissage olfactif perceptif : plasticité structurale et contrôle noradrénergique." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1182/document.
The field of neuroscience has experienced explosive growth over the past decade toward understanding the neural correlates of perception. More specifically, the adult brain responds to environmental experience by significant functional and structural modifications, called "neural plasticity" which underlies learning. A main issue in neuroscience is to understand the cellular basis of perceptive plasticity and subsequent behavioral adaptations. Contrary to previously held beliefs about its static nature, the adult brain is in fact capable of generating new neurons that can integrate into its complex circuitry. The birth of new neurons constitutively occurs in two specific regions of the adult mammalian brain (OB and hippocampal dentate gyrus). Adult neurogenesis is a sophisticated biological process whose function has remained a mystery to neuroscience researchers but a role in learning and memory has been proposed. Previous work in our group have shown that perceptive olfactory learning depends on adult neurogenesis. In addition, neuromodulatory systems, including noradrenergic and cholinergic systems massively innervate the olfactory bulb and more specifically the inhibitory interneurons targeted by adult neurogenesis and are long-known for their role in learning and memory. One objective of the present work was to determine the spatial and temporal pattern of the innervation by noradrenergic and cholinergic inputs of developing adult-born neurons and to investigate its modulation by learning. For that purpose, we used behavioral and neuro-anatomical approaches. Another objective was to assess the functional role of centrifugal contacts using an optogenetic approach. Results indicate that the noradrenergic innervation is selectively increased on adult born neurons following perceptual olfactory learning, a phenomenon that was not observed for cholinergic innervation, pointing the noradrenergic system as a key mechanisms involved in perceptual learning. Interestingly, noradrenergic contacts on neurons born during ontogenesis were not affected by learning, suggesting a very specific part played by adult-born neuron in learning associated plasticity. In the same brains, we have analyzed the structural plasticity induced by learning in adult-born and pre-existing neurons. The major finding is that mirroring the increased number of noradrenergic contacts, learning induced an increase in dendritic spines on adult-born, but not on pre-existing neurons
Audrain, Pascal. "Contrôle actif de l'intensité structurale dans une poutre." Le Mans, 2001. http://cyberdoc.univ-lemans.fr/theses/2001/2001LEMA1009.pdf.
This thesis deals with active vibration control in one dirnensional structures. The control of flexural and extensional structural power flow is investigated. The instantaneous intensity is completely taken into account in the control algorithm, i. E. All the terms are considered in the real-time control process and, in particular, the evanescent waves are considered in this approach. The structural intensity has to be calculated from signals measured by several sensors. To do so, an intensity probe rnade of PVDF strain sensors is developped. The PVDF sensors are well suited for integration into structure in order to realize smart structures. A wave decomposition of the displacement field is used to calculate the structural power flow. A structural intensity optimal active control scheme is formulated and the numerical simulations illustrate the performance of this strategy. Experimental validation of the approach is conducted on a free-free beam and on a beam connected to a plate. A feedforward filtered-X LMS algorithm is adapted to control instantaneous intensity associated with flexural and extensional waves. This energy-based control problem involves a non-positive definite quadratic form in general. In this respect, the approach is limited to cases where the geometry is such that the intensity component will have the same sign for the control source and the primary disturbance. A finite difference scheme using PVDF strain sensors is presented and validated to measure and control structural power flow. The results show this strategy can be used to control vibration transfert in structures
Endress, Maxime. "Neuropeptides et phéromones sexuelles impliqués dans le contrôle de la ponte chez la seiche Sepia Officinalis." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC208/document.
The common cuttlefish (Sepia officinalis) is a Cephalopod mollusk found on the Normandy coasts. In the Bay of Seine, it is the third species targeted by offshore and coastal fleets, so it is an important economic resource for the whole region. In a context of resource protection, the study and understanding of its reproductive mechanisms is a major objective. This study is therefore focused on the regulatory mechanisms of egg-laying, and in particular on the factors involved in the release of oocytes. Previous research in the laboratory demonstrated multifactorial control of the egg-laying process, with three levels of regulation: (i) neuropeptides involved in the perception of environmental cues, (ii) ovarian factors providing paracrine regulation of the genital tract, and (iii) sexual pheromones, which are implied in egg-laying and are suspected to play a determining role in the reproductive behavior. This thesis highlights the role of two families of recently identified neuropeptides called CCAPs and FLGamides (or So-orcokinins B). These two families participate in oocyte transport and in egg capsule secretion by acting on the contractile activity of the oviduct/oviduct gland complex and of the main nidamental glands. These neuropeptides are also suspected to play a role in the biosynthesis of yolk and capsular proteins. At the same time, sex pheromones are expressed by the oviduct gland and secreted along with capsular proteins. Previous work made it possible to characterize expression products resulting from cleavages of the prohormone convertase type. In this new study, a second mode of cleavage is highlighted, evidenced by the identification of cleavage products with MWs greater than 20 kDa. One of these products, beta pheromone, was produced in a recombinant system but its biological activity on the male reproductive system and on the oviduct was not demonstrated. As for behavioral tests, they were not exploited because the number of animals tested was too small. Finally, a comparative and differential transcriptomic approach of the male olfactory organ and the oviduct pavilion evidenced a candidate receptor expected to bind to sex pheromones
Vu, Duc-Chuan. "Contrôle sismique des structures." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLY015/document.
This thesis is motivated by various questions that arise regarding the use of base isolation in the nuclear industry. Unlike the majority of previous work on base isolation in general and mixed isolation in particular, which focus mainly on the response of the isolated structure (interstorey drifts, maximum accelerations of floors, etc.), this work focuses on the behavior of equipment, through the study of floor response spectra. The main objective is to reduce the deformation of the isolators without amplification of the response of the higher modes, which may appear under certain conditions and which can be a source of equipment solicitation. To this end, alternatives to the commonly used base isolators are explored. These are combinations of a low damping rubber bearing with a Maxwell element (relaxation isolator) or a semi-active hydraulic damper (mixed base isolation system).Maxwell element behaves like a damper in low frequency and as a low stiffness spring in high frequency. Hence it meets the above objectives. . Regarding isolation systems, three semi-active control techniques are proposed. In order to improve the performance of the control, the seismic excitation and the characteristics of the damper are taken into account in the design of the controller. Numerical analyzes confirm the effectiveness of these systems. Having in mind implementation of these methods to real structures, some practical aspects such as, observation of the system, effects of model reduction, considered by the controller, or time delay on the control performance, as well as the control of a set of redundant semi-active devices, are also studied
Koelsch, Magali. "Nanoparticules de TiO2 : contrôle structural, morphologique, dimensionnel et propriétés électrochimiques." Paris 6, 2004. http://www.theses.fr/2004PA066175.
Vu, Duc-Chuan. "Contrôle sismique des structures." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLY015.
This thesis is motivated by various questions that arise regarding the use of base isolation in the nuclear industry. Unlike the majority of previous work on base isolation in general and mixed isolation in particular, which focus mainly on the response of the isolated structure (interstorey drifts, maximum accelerations of floors, etc.), this work focuses on the behavior of equipment, through the study of floor response spectra. The main objective is to reduce the deformation of the isolators without amplification of the response of the higher modes, which may appear under certain conditions and which can be a source of equipment solicitation. To this end, alternatives to the commonly used base isolators are explored. These are combinations of a low damping rubber bearing with a Maxwell element (relaxation isolator) or a semi-active hydraulic damper (mixed base isolation system).Maxwell element behaves like a damper in low frequency and as a low stiffness spring in high frequency. Hence it meets the above objectives. . Regarding isolation systems, three semi-active control techniques are proposed. In order to improve the performance of the control, the seismic excitation and the characteristics of the damper are taken into account in the design of the controller. Numerical analyzes confirm the effectiveness of these systems. Having in mind implementation of these methods to real structures, some practical aspects such as, observation of the system, effects of model reduction, considered by the controller, or time delay on the control performance, as well as the control of a set of redundant semi-active devices, are also studied
Ryckelynck, David. "Sur l'analyse des structures viscoplastiques : stratégie adaptative et contrôle de qualité." Cachan, Ecole normale supérieure, 1998. http://www.theses.fr/1998DENS0003.
Nazaraly, Micaela. "Contrôle morphologique, dimensionnel et structural de particules de phosphate de cérium (IV)." Paris 6, 2013. http://www.theses.fr/2006PA066800.
This thesis deals with the synthesis, by precipitation in aqueous solution, of cerium (IV) (CePs) phosphates and the study of their structures. Many studies, done since the sixties, showed that these compounds exhibiting interesting properties as cationic exchangers. However, no relation between these properties and the structural chemistry of CePs has been established as no structurehas ever been solved. A versatile synthesis of CePs based on Ce(NO3)6(NH4)2, nitric acid, phosphoric acid was developed Variation of the synthesis parameters (P/Ce ratios: 0. 5-10, solution acidity: 0. 05-6 M, ageing time at 95)C: 18h-28d) showed that many compounds could be obtained. These compounds have different XRD patterns, they also have different composition morphology. The structure of a stable compound Ce( PO4) ( HPO4) 1/2 ( H2O) 1/2 has been solved by ab-initio Rietveld analysis. It corresponds to a bridged - lamellar. The structure of a kinetic compound, Ce( PO4) 3/2 ( H2O) ( H3O) 1/2 ( H2O) 1/2, has also been solved by single crystal X-ray diffraction. It corresponds to a 3D negatively charged framework with tunnels in which hydronium cations and free water molecules are located. Two other original CePs, Ce(PO4) (NO3) (H2O) 2 and Ce (PO4) (H2PO4) (H2O) 3/4, were synthesized by using Ce(NO3)6(NH4)2, Ce(NO3)4, CE(ClO4)4 or CeO2. Since these two compounds were intercalated by primary amines, we can suggest that these compounds are lamellar solid. Exfoliation properties were also tested for these compounds
Poinçot, Flavien. "Le contrôle des émissions de N₂O par l'état structural des sols." Thesis, Orléans, 2019. http://www.theses.fr/2019ORLE2001/document.
Agricultural soils account for 66 % of anthropogenic nitrous oxide emissions (N₂O), the 3rd greenhouse gas emitted from anthropogenic activities. N₂O emissions variability measured in-situ is quite high. Soil structure affects both N₂O production processes and N₂O movements through the soil profile. The main goal of this work was to understand the part of soil structure in soil N₂O spatial variability. Two kinds of laboratory experiments were designed: rainfall experiments on soil trays of 0.3 m² x 0.1 m and on a 10 m² x 0.3 m box with a slope. A modelling approach with a short time step was combined, involving representation of physical, chemical and biological soil processes as well as a representation of surface runoff.This work highlighted a hierarchy between N₂O production and N₂O transportation processes, which evolve with time and environmental conditions: under conditions that favor denitrification, N₂O production increases with soil bulk density due to an increase in the water-filled pore space, until a threshold limit. The deterministic modelling approach showed that rainfall dynamic and resulting runoff affect soil N₂O emissions, those emissions occurring later downslope. Finally, this work highlighted the complexity of soil N₂O emissions determinism and we pointed out that the description of soil structure at a high spatial resolution would be useful to improve modelling quality
Authié, Colas. "Contrôle visuel du déplacement en trajectoire courbe : approche sensorimotrice du rôle structurant du flux optique." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22085.
The main purpose of this dissertation is to determine the role of the direction and movement of the eyes and the head in the perception and control of self-motion in curved trajectories, with respect to the properties of the optical flows generated in a stable environment. To do so, we used two experimental methods: a psychophysical approach which allows to assess human observers' ability to perceive the direction of self-motion; and a behavior-based approach on a driving simulator. The two methods combined should help to highlight active perception of self-motion.The introduction reviews the current knowledge of perceptuo-motor strategies during curve driving. In this context, we put a stress on both (1.) the particular role of the tangent point -- in the driving situation on a delimited road, and on the role of the optic flow in general (apparent transformation of the optic array during self-motion), emphasizing the capability of humans to spatially interpret the movement; and (2.) on the duality between movement and perception. We then address the role of head-and-eye combined movements, in a functional perspective of the control of self-motion. In a first experimental section, we analyze the oriented movements of the head in simulated curve driving. We demonstrate that head movements are independent from the handling of the steering wheel, and that they actively participate in the gaze orientation toward the tangent point.In a second experimental section, we set out to describe the combined movements of head and eyes, with respect to the geometry of the road environment. In a third section, we analyze in more details gaze behavior as a function of the tangent point direction and of the local speed of optical flow. We demonstrate that the tangent point corresponds to a local minimum of optic flow speed and that the global component of the optic flow induces a systematic optokinetic nystagmus. In a fourth section involving a psychophysical study, we scrutinize the effect of varying gaze direction on the discrimination of the direction of self-motion. We show that the trajectory discrimination thresholds are minimal when the gaze is oriented toward an area of minimum flow speed. We finally propose a model of trajectory change detection, relying on a Weber fraction of foveal flow speeds, predicting the experimental thresholds very precisely. The gaze orientation strategies we have observed (combination of head and eye movements) toward the tangent point are compatible with this model and with the hypothesis of an active an optimal selection of the information contained in the optical flow
Chang, Zheng. "Préparation contrôlée, caractérisation structurale et applications d'hydroxydes doubles lamellaires contenant des terres rares." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2006. http://tel.archives-ouvertes.fr/tel-00703250.
Ding, Wenxiang. "Structural health monitoring of piezoelectric ultrasonic transducers." Electronic Thesis or Diss., Bourges, INSA Centre Val de Loire, 2021. http://www.theses.fr/2021ISAB0008.
Ultrasonic transducers have been widely used in medical diagnostic, therapy, non-destructive evaluation, cleaning, underwater sonar, and other applications. The proper functioning of the transducer itself is a key factor in the reliability of the entire system. However, due to the misuse of operators or material degradation, defects may occur, such as breakages in cables, cracks, damaged or weakened crystals, and delamination between layers. This contribution focuses on a detail analysis of the influence of bonding delamination on the performance of the transducer, aiming to determine procedures to facilitate the monitoring of the behavior of the transducer during its lifetime and the detection of degradations before they significantly affect the performance of the system.In the frame of this work, an original two-dimensional analytical model for coupled vibrations of finite piezoelectric resonators is proposed. General solutions for all the physical quantities in Cartesian and cylindrical coordinate systems are deduced from the governing equations. They are expressed as a series of trigonometric or Bessel functions. Electrical impedance, mode shape, and frequency spectrum of piezoceramics are calculated by the proposed analytical method as well as by the finite element method. Comparison of the results of these two methods shows an excellent agreement.A systematic investigation of the influence of different kinds of bonding delamination on the performance of single-element and linear array ultrasonic transducers is presented. Finite element models are developed to show the impact of bonding delamination as well as other factors on the electromechanical admittance (EMA) of ultrasonic transducers, which are composed of a piezoceramic disk or parallelepiped, a backing, and a matching layer. Experimental studies are set up to validate the models and quantitative indicators are proposed. 3D printed backings and matching layers are mounted on piezoceramic elements to obtain an intact model transducer and delaminated ones. Comparison between numerical and experimental results show a good agreement, which allows to affirm that changes in EMA can reveal the occurrence and extent of a delamination in an ultrasound probe
Lallart, Mickaël. "Amélioration de la conversion électroactive de matériaux piézoélectriques et pyroélectriques pour le contrôle vibratoire et la récupération d'énergie - Application au contrôle de santé structurale auto-alimenté." Phd thesis, INSA de Lyon, 2008. http://tel.archives-ouvertes.fr/tel-00367302.
L'objectif des travaux présentés est triple. Tout d'abord il s'agit de développer des techniques de contrôle vibratoire limitant la fatigue des matériaux et répondant aux contraintes énergétiques des systèmes embarqués.
Ensuite de nouvelles méthodes améliorant la récupération d'énergie ambiante sont exposées. Reposant sur un traitement non linéaire, ces techniques permettent un gain important en termes de puissance de sortie.
Enfin, des techniques de contrôle de santé structurale nécessitant une énergie très faible sont présentées, permettant ainsi le suivi à moindre coût de l'évolution de la structure.
Ces trois points seront finalement combinés, démontrant ainsi la faisabilité de contrôle de santé structurale totalement auto-alimenté. Cette dernière partie a été effectuée dans le cadre du projet européen ADVICE.
Mrabet, Elyes. "Optimisation de la fiabilité des structures contrôlées." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEC011/document.
The present work deals with the parameters optimization of tuned mass dampers (TMD) used in the control of vibrating linear structures under stochastic loadings. The performance of the TMD device is deeply affected by its parameters that should be carefully chosen. In this context, several optimization strategies can be found in the literature and among them the stochastic structural optimization (SSO) and the reliability based optimization (RBO) are particularly addressed in this dissertation.The first part of this work in dedicated to the calculation of the optimal bounds solutions of the TMD parameters in presence of uncertain but bounded (UBB) structural parameters. The bounds of the optimal TMD parameters are obtained using an approximation technique based on Taylor expansion followed by interval extension. The numerical investigations applied with one degree of freedom (1DOF) and with multi-degree of freedom (multi-DOF) systems showed that the studied technique is suitable for the SSO strategy and that it’s less appropriate for the RBO strategy.As immediate consequence of the obtained results in the first part of this work, in the second part a method, called the continuous-optimization nested loop method (CONLM), providing the exact range of the optimal TMD parameters is presented and validated. The numerical studies demonstrated that the CONLM is time consuming and to overcome this disadvantage, a second method is also presented. The second method is called the monotonicity based extension method (MBEM) with box splitting. Both methods have been applied in the context of the RBO strategy with 1DOF and multi-DOF systems. The issue of effectiveness and robustness of the presented optimum bounds of the TMD parameters is also addressed and it has been demonstrated that the optimum solution corresponding to the deterministic context (deterministic structural parameters) provide good effectiveness and robustness.Another aspect of RBO approach is dealt in the third part of the present work. Indeed, a new RBO strategy of TMD parameters based on energetic criterion is presented and validated. The new RBO approach is linked to a new failure mode characterized by the exceedance of the power dissipated into the controlled structure over a certain threshold during some interval time. Based on the outcrossing approach and the Rice’s formula, the new strategy is firstly applied to 1DOF system and exact expression of the failure probability is calculated. After that, a multi-DOF system is considered and the minimum cross entropy method has been used providing an approximation to the failure probability and then the optimization is carried out. The numerical investigations showed the superiority of the presented strategy when compared with other from the literature
Hautefeuille, Alexandre. "Couplage écoulement-déformation des renforts fibreux dans les procédés de mise en oeuvre des composites structuraux : Étude expérimentale, modélisation et contrôle." Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0047.
For the purpose of lightening structures, the transport industry has, for several years, been moving towards the production of large composite parts. The use of manufacturing processes with a strong hydromechanical coupling is essential to meet the growing needs for reduced cycle times. A key step in the process is the consolidation of the pre-impregnated fabric during composite processing. This step consists in complete the impregnation of the fluid in the fibrous reinforcement by transverse compression of the prepreg. The latter can generate a fluid flow over long distances (for example in the case of the I/C-RTM process). The use of high viscosity resins (sometimes above 10 Pa.s) coupled with high compression rates can generate a flow with the capacity to deform the fibrous architecture. The coupling between flow and induced deformations is addressed in this thesis. The objectives are to identify, quantify and control the mechanisms involved during the coupling of the flow and the deformation of the reinforcement. The development of specific experimental allowed to identify a mechanical signature, and then to localize the phenomenon of fibre washout on a large flat part. A model has been developed to integrate these induced deformations into the calculation of the fluid pressure field during the consolidation of the composite material. The flow resistance offered by the fibrous reinforcement is linked to the intra-pli friction. The development of a measurement bench allowed to quantify this resistance. Finally, the balance between the viscous drag and the friction forces is modelled to anticipate flow-induced in-plane deformations. This model results in the control of consolidation by driving the compression speed
Li, Kaixiang. "Structural vibration damping with synchronized energy transfer between piezoelectric patches." Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00735788.
Maolood, Nasren. "Contrôle noradrénergique de la plasticité neurochimique et structurale dans le noyau supra-optique de l'hypothalamus chez la souris." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2007. http://tel.archives-ouvertes.fr/tel-00167335.
Nous avons utilisé un modèle ex-vivo de tranches d'hypothalamus (400µm) de souris C3H mâle, contenant les NSO, maintenues en survie dans une chambre d'incubation, dans différentes conditions pharmacologiques. Ces tranches ont subi des traitements pharmacologiques pour 1h ou 4h en présence de la NA. Afin de déterminer l'implication du NO ou des MMP dans la voie de signalisation de la NA, des traitements par le L-arginine méthyl ester (L-NAME, inhibiteur de NO), le sodium nitroprusside (SNP, donneur de NO), l'EGTA (bloquer du Ca+2), et la phénanthroline (inhibiteur de MMP) ont été réalisé. Une quantification des deux peptides synthétisés par les neurones magnocellulaires dans ces conditions a été réalisée par le dosage immunoenzymatique, et l'étude de l'expression et de l'activité des différents peptides et facteurs a été réalisée par immunohistochimie, histoenzymologie, et zymographie in situ.
Dans la première partie de ce travail, nous avons montré que la NA stimule l'expression de l'AVP et de l'OT validant ainsi notre modèle ex-vivo par rapport aux modèles in-vivo. Parallèlement, une augmentation de l'expression et de l'activité de la nNOS et la iNOS, ainsi que l'activité de la NADPH-diaphorase par la NA a été observé dans les neurones magnocellulaires du NSO. Aucune détection de la eNOS n'a été observée. L'utilisation de L-NAME au cours du traitement NA nous a permis de montrer que le NO est impliqué dans la voie de régulation de l'AVP par la NA mais pas dans celle de l'OT. L'analyse immunoenzymatique en utilisant un bloqueur de l'activité de la nNOS nous a permis de constater que le NO impliqué dans la régulation d'AVP par la NA provient à la fois de l'activité de la nNOS et de la iNOS.
Dans le deuxième partie, nous avons montré que la plasticité neurochimique induite par la NA pourrait impliquer des molécules de la MEC. Nous avons montré que la MMP2 et la MMP9 sont exprimées dans des neurones vasopressinergiques, ocytocinergiques, ainsi que dans les astrocytes. Nous avons ensuite montré que la NA augmente l'expression et l'activité de ces MMPs dans les neurones magnocellulaires du NSO. L'implication de la MMP2 et de la MMP9 dans la régulation de l'AVP et de l'OT par la NA, réalisée par immunohistochimie en utilisant un inhibiteur des MMPs, a permis de suggérer que ces MMPs pourraient être un des facteurs impliqués dans la plasticité des neurones magnocellulaires du NSO.
Hadani, Mohamed. "Contrôle structurale de l'intrusion granitique de tawrirt (secteur d'adassil); implications à l'évolution géodynamique du haut-atlas occidental (Maroc)." Master's thesis, Universidade de Évora, 2003. http://hdl.handle.net/10174/15477.
Tassy, Aurélie. "Karsts côtiers et canyons sous-marins de la marge provençale au Cénozoïque : Contrôle géodynamique, eustatique, hydrologique et structural." Phd thesis, Aix-Marseille Université, 2012. http://tel.archives-ouvertes.fr/tel-00830299.
Msellak, Khalid. "Electrodéposition métallique sous contrôle MHD : caractérisation physique et électrochimique." Reims, 2003. http://www.theses.fr/2003REIMS008.
This work analyzes the influence of a magnetic field parallel to the electrode on two electrochemical systems of industrial interest : the deposit of Cu on substrates inducing no epitaxy and deposits of Ni-Fe alloys. The characterization of the deposits was led with several physical and electrochemical techniques. The results show that : The magnetic field does not modify the nucleation of Cu on a conductive substrate (glassy C or Ti) : the only measurable results are the magneto-induced convective effects on the growth of Cu. On TiO2, a phenomenon of anisotropy confirms the existence of a transverse electric field. The phenomenon, sensitive with moderate fields, was put in evidence in a spectacular way under the intense fields available on the LMCI of Grenoble. For electrodeposition of Ni-Fe alloys, the results show that the magnetic field increases the convective rate of the ferrous ions to the electrode. These species inhibit the Ni deposit and lead to alloys considerably enriched in Fe
Brizard, Denis. "Contrôle des vibrations de charge utile sur lanceur spatial." Thesis, Ecully, Ecole centrale de Lyon, 2011. http://www.theses.fr/2011ECDL0041/document.
Space launchers undergo a certain amount of complex excitations during their lifecycle. These excitations are transmitted to the payload in a structure-born or air-born way. To improve the dynamic behaviour and thus ensure the protection of the payload, secondary systems must be added to the launcher – indeed, the architecture of the launcher is fixed at the beginning of the project. The essential part of this thesis work is dedicated to the optimal fitting of a system capable of reducing the vibration response of the payload, using appropriate models. Therefore a double modal synthesis method is implemented, allowing to calculate the vibrational response of the structure with reduced bases and offering improved performances over conventional methods. The addition of a local damping device requires the consideration of one or more structural modifications in the model, a dedicated method is thus developped along with a specific continuation algorithm. A friction damper is retained, a prototype is designed and built. It is first characterized alone ; the identified behaviour is that of a spring in series with a dry friction element, a simple Coulomb friction law enables to reproduce the experimental curves. A scale model of the launcher’s last stage is designed and built. The friction device is then mounted inside the scale model and leads to a significant reduction of the payload vibration levels
Cariou, Charles. "Stratégie de contrôle actif de bruit harmonique moyenne fréquence dans un habitacle." Rouen, 1999. http://www.theses.fr/1999ROUES022.
Nerlikar, Vivek. "Digital Twin in Structural Health Monitoring for Aerospace using Machine Learning." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASG080.
Modern engineering systems and structures often utilize a combination of materials such as metals, concrete, and composites, carefully optimized to achieve superior performance in their designated functions while also minimizing overall economic costs. Primarily, engineering structures are subjected to dynamic loads during their operational life. The manufacturing issues and/or the perpetual dynamic operations often lead to some changes into a system that adversely impact its present and/or future performance; these changes can be defined as damage. The identification of damage is a crucial process that ensures the smooth functioning of equipment or structures throughout their life cycle. It alerts the maintenance department to take the necessary measures for repair. Structural Health Monitoring (SHM) is a potential damage identification technique which has attracted more attention in the last few decades. It has the capability to overcome the downsides of traditional Non-Destructive Testing (NDT). In this thesis, we used Ultrasonic Guided Waves (GW) technique for SHM. However, sensitivity of GW to Environmental and Operational Conditions (EOC) modify the response signals to mask defect signatures. This makes it difficult to isolate defect signatures using methods such as baseline comparison, where damage-free GW signals are compared with current acquisitions Baseline-free methods can be an alternative, but they are limited to simple geometries. Moreover, high sensitivity of GW to EOC and measurement noise poses a challenge in modelling GW through physics-based models. The recent advancements in Machine Learning (ML) has created a new modelling axis, including data-driven modelling and physics-based modelling, often referred to as Scientific ML. Data-driven modelling is extremely helpful to model the phenomena that cannot be explained by physics, allowing for the isolation of subtle defect signatures and the development of robust damage detection procedures. However, ML-based methods require more data to capture all the information to enhance the generalization capability of ML models. SHM, on the other hand, tends to generate mostly damage-free data, as damage episodes seldom occur. This particular gap can be filled through physics-based modeling. In this approach, the modeling capabilities of physics-based models are combined with measurement data to explain unexplainable phenomena using ML. The primary objective of this thesis is to develop a data-driven damage detection methodology for identifying defects in composite panels. This methodology is designed for monitoring similar structures, such as wind or jet turbine blades, without requiring pristine (damage-free) states of all structures, thereby avoiding the need for direct baseline comparisons. The second goal is to develop a physics-based ML model for integrating physics-based simulations with experimental data within the context of a Digital Twin. The development of this physics-based ML model involves multi-fidelity modeling and surrogate modeling. To validate this model, we utilize an experimental and simulation dataset of an Aluminium panel. Furthermore, the developed model is employed to generate realistic GW responses at the required damage size and sensor path. These generated signals are then used to compute a Probability of Detection (POD) curve, assessing the reliability of a GW-based SHM system
Matioszek, Dimitri. "Conception de nouvelles espèces divalentes du groupe 14 (Ge, Sn) : réactivité et synthèse contrôlée de nano-objets." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1438/.
This work concerns the synthesis of single-element (Ge, Sn) and alloys (SiGe, GeSn, SnSi) nano-objects from group 14 derivatives specifically designed for this purpose. These species present a double challenge: they have to be stable enough to be handled easily and to remain labile to decompose in mild conditions of temperature. For this, two sets of low-coordinate germanium compounds (oxidation state II) have been prepared and characterized. The first one contains N-chelating ligands (aminotroponiminate and amidinate) which allow stabilization by intramolecular complexation. The oxidative reaction with an ortho-quinone and the complexation reaction with transition metals have confirmed their specific character of divalent sites. Their thermolysis in solution led to photoluminescent nanoparticles with a size in the range of 2. 5 to 5 nm surrounded by an organic layer that protected them from oxidation. The second set was devoted to the synthesis of di- and poly-metallated group 14 complexes (hypermetallyl-germylenes and -stannylenes) stabilized by inter- or intra-molecular complexation. They are potential precursors for group 14 nanoscale alloys with totally unique properties
Chemin, Alexandre. "Analyse isogéométrique multiéchelle à précision contrôlée en mécanique des structures." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0098/document.
Isogeometric analysis applied to structural mechanics problems is a topic of intense concerns for a decade. Indeed, an exact description of geometries studied is allowed by this discretization method suppressing errors due to a bad description of the spatial domain considered. However, a theoretical problem of refinement propagation appears during mesh localization. Local refinement methods for isogeometric analysis has been developed and implied a complexification of the implementation of such a resolution strategy. This PhD thesis expose a space adaptative refinement strategy for linear elastic problems and a space-time one for transient dynamic using isogeometric analysis. For this purpose, a localization method for isogeometric analysis based on a multigrid resolution is developed for 2D linear elastic problems. This method allow to circumvent mesh refinement propagation inherent to isogeometric analysis, and is easier to implement than existing methods. Moreover, the use of isogeometric analysis simplifies refinement procedures occuring during mesh adaptation and which can be really complex using classical finite element analysis. Then, a space-time adaptative refinement based on a multigrid resolution is developed for one dimensional in space problems. A study on operators structure is exposed in order to choose a well suited time integrator. This strategy's performances are highlighted, then an evolution of this method is set up in order to lower computational costs. The space-time adaptaptive refinement is applied to some academical examples to show it good behavior during localization
Tuloup, Corentin. "Process and structural health monitoring of Polymer-Matrix Composites (PMC) using embedded piezoelectric transducers." Thesis, Compiègne, 2020. https://bibliotheque.utc.fr/Default/doc/SYRACUSE/2020COMP2593.
This innovative work studies the interest of integrating piezoelectric transducers (ceramic and/or polymer-based) within Polymer- Matrix Composite materials (PMC) to perform real-time and in-situ monitoring of their manufacturing process (Process Monitoring PM) as well as their lifespan (Structural Health Monitoring SHM). To do this, the piezoelectric transducers were integrated into the heart of the fibrous stacks using an innovative methodology developed within the "Materials and Surfaces" research team at the Roberval laboratory. The Liquid Resin Infusion (LRI) manufacturing system used (PM campaign), as well as the resulting samples tested mechanically (SHM campaign), were multi-instrumented using several Non-Destructive Testing devices (NDT: Acoustic Emission (AE), Infrared Thermography (IRT), Digital Image Correlation (DIC), etc.) in order to establish multi-physical couplings between the signals of external NDT techniques and the internal signature (electrical capacitance) coming from the transducers integrated into the heart of the material. In PM, the piezoceramic (PZT) transducers were found to be sensitive to the various key steps of the LRI process (flow front passing, impregnation, end of injection, chemo-physical transitions during curing and associated consolidation rates) achieved at different hardener rates, and able to detect manufacturing defects. These results showed great potential, worthy of future use on an industrial scale. In SHM, after verification of the non-intrusiveness of the ceramic and polymer-based transducers integrated into the heart of the mechanical test specimens, the polymer transducers allowed a real-time evaluation of the triaxial strain state and the rigidity loss experienced by the host PMC during its mechanical loading. However, despite a Non-Working Threshold (NWT) linked to the brittleness of their constitutive material, the piezoceramic transducers have shown a high sensitivity to the detection and monitoring of damage in real-time when they are positioned intelligently with respect to the mechanical stress. These thesis works ended with a first attempt aimed at transposing the knowledge acquired on PM and SHM of in-situ piezoelectric transducers from a 2D “laboratory” scale to a 3D structural one closer to industrial realities. The multi-instrumented manufacturing of an “Omega” stiffener PMC structure integrating 14 piezoelectric transducers (PZT and P(VDF-TrFE) copolymer) and reinforced through-the-thickness by a carbon tuft thread allowed confirming the previously evidenced PM abilities of the PZT, and showed a difference between how the electrical capacitance signals of PZT and copolymers react to the whole manufacturing process
Pardo, Jérémie. "Méthodes d'inférence de cibles thérapeutiques et de séquences de traitement." Electronic Thesis or Diss., université Paris-Saclay, 2022. http://www.theses.fr/2022UPASG011.
Network controllability is a major challenge in network medicine. It consists in finding a way to rewire molecular networks to reprogram the cell fate. The reprogramming action is typically represented as the action of a control. In this thesis, we extended the single control action method by investigating the sequential control of Boolean networks. We present a theoretical framework for the formal study of control sequences.We consider freeze controls, under which the variables can only be frozen to 0, 1 or unfrozen. We define a model of controlled dynamics where the modification of the control only occurs at a stable state in the synchronous update mode. We refer to the inference problem of finding a control sequence modifying the dynamics to evolve towards a desired state or property as CoFaSe. Under this problem, a set of variables are uncontrollable. We prove that this problem is PSPACE-hard. We know from the complexity of CoFaSe that finding a minimal sequence of control by exhaustively exploring all possible control sequences is not practically tractable. By studying the dynamical properties of the CoFaSe problem, we found that the dynamical properties that imply the necessity of a sequence of control emerge from the update functions of uncontrollable variables. We found that the length of a minimal control sequence cannot be larger than twice the number of profiles of uncontrollable variables. From this result, we built two algorithms inferring minimal control sequences under synchronous dynamics. Finally, the study of the interdependencies between sequential control and the topology of the interaction graph of the Boolean network allowed us to investigate the causal relationships that exist between structure and control. Furthermore, accounting for the topological properties of the network gives additional tools for tightening the upper bounds on sequence length. This work sheds light on the key importance of non-negative cycles in the interaction graph for the emergence of minimal sequences of control of size greater than or equal to two
Ntiharirizwa, Seconde. "Les minéralisations en Eléments de Terres Rares de la région de Gakara (Burundi) : contrôle structural, caractérisation pétrologique et géochimique, modèle métallogénique." Thesis, Rennes 1, 2019. https://ged.univ-rennes1.fr/nuxeo/site/esupversions/2613ecfc-fc24-4a52-84c9-f0ea9d943359.
The Gakara deposit in Burundi is one of the richest deposits of Rare Earth Elements (REE) in the world. The East African rift zone is the well-known host of many carbonatites and associated alkaline complexes, which have been in place for many hundred million years. The main deposits of REE mined today in the world are associated with carbonatite complexes. In these complexes, mineralization is rarely part of the primary mineral assemblage; they precipitate from fluids evolved from magmatic intrusions. To better understand the mechanisms of emplacement of REE mineralization in the Gakara area, we used a multidisciplinary approach: i) A geological study based on field observations and a study of the mineralogical composition and textures of different facies of the ore, using conventional microscopic observation tools. ii) In-situ U-Th-Pb dating by La-ICP-MS to determine the ages of primary mineralization (veins of bastnaesite, REE-fluorocarbonate) and hydrothermal alteration (monazitic alteration, REE-phosphate). iii) A detailed study of the fluid inclusions trapped in bastnaesite and quartz crystals associated with the monazitic alteration to characterize the mineralizing fluids and thus specify their nature and physicochemical conditions of emplacement. iv) A study of stable isotopes of carbon and oxygen on bastnaesite and quartz to give a complementary indication of the origin of the mineralizing fluids and the mechanisms involved. v) The integration of geophysical and geochemical data acquired by Rainbow Company during its prospecting campaigns to compare them with field geology data in order to better understand the formation mechanisms of the Gakara deposit as well as to discuss the identification of new mineralized zones. All the data acquired in these different studies and the main observations allow to establish a global metallogenic model of Gakara area. Mineralization is results from the deposition of REE in hydrothermal conditions in the upper crust, from exsolved fluids of a probably carbonatitic magma, fluids having subsequently undergone CO2 vapor – aqueous brine separation. This phase separation was probably the main precipitation mechanism of REE minerals. The implication of surrounding fluids, with very low salinity, possibly coming from the surface, is suggested. Mineralization took place during the pan-African tectonic event, at about 600 Ma, and was affected by recent deformations, possibly associated with the development of the East-African rift
Ghrib, Meriem. "Contrôle santé des structures composites : génération de délaminages par choc laser et quantification par apprentissage machine." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0070/document.
In this work, we approach delamination quantification in Carbon Fiber Reinforced Polymer (CFRP) laminates as a classification problem whereby each class corresponds to a certain damage extent. A Support Vector Machine (SVM) is used to perform multi-class classification task. Classically, Signal Based Features (SBF) are used to train SVMs when approaching SHM from a machine learning perspective. In this work, starting from the assumption that damage causes a structure to exhibit nonlinear response, we investigate whether the use of Nonlinear Model Based Features (NMBF) increases classification performance. NMBF are computed based on parallel Hammerstein models which are identified with an Exponential Sine Sweep (ESS) signal. Dimensionality reduction of features vector using Principal Component Analysis (PCA) is also conducted in order to find out if it allows robustifying the quantification process suggested in this work. The proposed quantification approach was first tested and validated using simulation results. Thereafter, experimental results on CFRP composite plates equipped with piezoelectric elements and containing various delamination severities are considered for demonstration. Delamination-type damage is introduced into samples in a calibrated and realistic way using LASER Shock Wave Technique (LSWT) and more particularly symmetrical LASER shock configuration. We have experimentally demonstrated that such a configuration of LASER shock is an effective alternative to conventional damage generation techniques such as conventional impacts and Teflon inserts since it allows for a better calibration of damage in type, depth and size
Chal, Robin. "Préparation de matériaux zéolithiques à mésoporosité contrôlée à l'aide d'agents structurants recyclables dans l'eau." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2012. http://www.theses.fr/2012ENCM0003.
Zeolites are widely used in acid catalysis, especially in petrochemistry. However, their activity is not optimal because of diffusional limitations imposed by their microporous structure. Various approaches have been proposed to circumvent these limitations, including the preparation of mesoporous zeolites. After an industrial assessment of the different methods reported in the literature, the first part of the thesis was devoted to the development, understanding and optimization of a procedure for preparation of zeolites with controlled mesoporosity using an organic structuring agent. We studied the recrystallization of the zeolite Y, which creates a large mesoporous volume in the zeolite crystals by pseudomorphic transformation. In the second part, we report the first synthesis of mesoporous zeolites using a structuring agent recoverable and recyclable under mild conditions in water. By synthesizing a structuring agent adapted to the conditions of thermal recrystallization, controlled mesostructure could be obtained within the zeolite. The extraction of the polymer in aqueous solution has been optimized and recycling of four cycles of recrystallization has been demonstrated
Langlois, Anne-Marie. "Influence de l'endommagement sur la fiabilité structurale de ponts en béton armé : étude de cas." Master's thesis, Université Laval, 2010. http://hdl.handle.net/20.500.11794/21327.
A computer program, named « Laval Reliability Toolbox 2 » (LRT2), was developed in order to evaluate a time-variant reliability index for a reinforced concrete bridge while considering various usage and damage parameters. This tool pioneers by considering the reliability of three ultimate limit states: flexure and shear for beams and punching shear for the slab. In order to represent the failure mode of the bridge, system reliability analysis is used to model the structure as a system. A damage model predicts in time the properties of a structure undergoing corrosion caused by the application of de-icing salts: corrosion causes a reduction of the rebar’s diameter and spalling of the concrete cover. This computer tool was used to compare the reliability of bridges with two, three, five and six girders undergoing different damaging scenarios. Results show the importance of considering a spatial-variant reliability index for a girder. It is also shown that ignoring possible correlation among structural elements overestimates the reliability of low-redundant structures, modelled as series systems, and underestimates the reliability of high-redundant structures, modelled as complex systems. The study of homogeneous and non-homogeneous damaging scenarios shows the existence of corrosion-sensitive sections and failure modes that, if damaged, affect significantly the reliability of the bridge. Lastly, performance cycles were defined in order to evaluate the life service of a bridge, which is to estimate the time when the bridge will get below its target reliability index and to estimate when certain damages will occur. This type of methodology enables the prediction of a structure’s lifetime performance; it could facilitate the management of structures operations by making possible the comparison of multiple bridges performance.
Zhu-Colas, Beiting. "Using knowledge-based MAS to build a reliable structural earth model." Paris 6, 2008. http://www.theses.fr/2008PA066529.
Druet, Tom. "Tomographie passive par ondes guidées pour des applications de contrôle santé intégré." Thesis, Valenciennes, 2017. http://www.theses.fr/2017VALE0032/document.
This manuscript presents a baseline-free quantitative method for the imaging of corrosion flaws present in thin plates. This method only requires an embedded guided waves sensors network in a fully passive way. The field ofapplications are Structural Health Monitoring (SHM) of critical structures with heavy constrains on both sensors intrusiveness and diagnostic reliability. A promising solution allowing to increase the number of measurement points without increasing the intrusiveness of the system is provided by the Fiber Bragg Gratings (FBGs). However, unlike piezoelectric transducers generally used in SHM, the FBGs cannot emit elastic waves. The idea consists in using passive methods in order to retrieve the Green function from elastic diffuse fields - naturally present in structures - measured simultaneously between two sensors. In this manuscript, two passive methods are studied: the ambient noise correlation and the passive inverse filter. It is shown that the latter gives better results when coupled with tomography. Several tomography algorithms are assessed with numerical simulations and then applied to active and passive datasets measured by a PZT network. In order to make passive tomography robust, a time of flight identification method is proposed, based on a time-frequency representation. Finally, a novel experimental demonstration of passive measurements with FBGs only is presented, suggesting high potential for FBGs passive tomography
Silva, Pires Viviane. "Synthèse, étude structurale et évaluation biologique de peptides et de peptidomimétiques à visée anti-thrombotique." Amiens, 2006. http://www.theses.fr/2006AMIED002.
This doctoral thesis aimed at synthesizing peptides and analogous peptides with an anti-thrombosis activity profile. The peptides allowed us to study the importance of peptide sequences as well as their structure as recognized by the TIIICBP receptor. The KBGEBGPK and KPGEPGPK reference octapeptides show an anti-thrombosis activity in vitro and in vivo. The incorporation of these reference sequences into the simple trimers increases the anti-thrombosis activity of the octapeptide sequences. However, when the reference octapeptide is incorporated into a peptide that mimics the collagen triple helix, the anti-thrombosis activity is suppressed in favor of a pro-thrombosis activity. The incorporation of a thiouracile-type probe into the side chain of the lysines in the positions 1 and/or 3 of the reference octapeptide sequence does not lead to a major change in the anti-thrombosis activity. This will make it possible to use these analogous peptides as a molecular tool to characterize TIIICBP
Gonzalez, Vieyra Joel Abraham. "Estimation et Contrôle des Systèmes Dynamiques à Entrées Inconnues et Energies Renouvelables." Thesis, Ecole centrale de Lille, 2019. http://www.theses.fr/2019ECLI0012/document.
Nowadays, industrial processes must be efficient, particularly at the production level and/or energy consumption.This research work aims at improving the process efficiency by analysing the influences of disturbances on their behaviour, from the conception phase to the synthesis of controller/observer, in an integrated approach.The disturbance rejection problem is first introduced as well as different control laws allowing attenuate/reject these disturbances. A control law based on the concept of derivative state variable is presented and validated while applied as disturbance rejection.In order to reject the disturbance, different physical variables must be estimated, such as state variables, derivative state variables as disturbance variables. An unknown input observer based on the bond graph representation is recalled and extended in the multivariable case. It is the first theoretical contribution of this work.We thus compare the efficiency of different so-called «modern control laws» for the disturbance rejection problems by simulation with the Torsion-Bar system example. We analyse the efficiency of our approach. One extension to the Input-Output decoupling problem allows us to extend the disturbance rejection problem to other control law type in an integrated approach. At least, these techniques are applied on the real Torsion-Bar system and compared. We validate our approach.Since this work aims at analysing and developing efficient control laws for industrial processes, a simplified model of a hydroelectric plant is developed, in order to apply our results. A simplified bond graph model is validated with simulations
Krishna, Aditya. "Topological Imaging of Tubular Structures using Ultrasonic guided waves." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0111.
Tubular structures are widely used in a variety of industries such as Aerospace, Oil and Gas, Nuclear, etc. Non Destructive Evaluation (NDE) of these structures plays a crucial role during it’s life cycle. In order to test large structures with limited accessibility, guided wave testing was developed as a viable solution. Due to the nature of these waves, they are able to propagate over large distances without losing much of their energy. However, they are also complex in that their velocity is frequency dependent i.e. they are dispersive. Conventionally, guided wave testing require costly finite element simulations. This thesis offers an alternative to such simulations with a quick and robust method to simulate guided wave propagation in tubular structures.Based on these calculations, the aim of this work is to obtain the 3d topological image of multilayered isotropic tubular structures using ultrasonic guided waves to locate defects. A mathematical model has been proposed where the wave equation is converted to an ordinary differential equation with respect to radius 'r' using the Fourier and Laplace transforms for the spatial and temporal variables respectively. The partial wave solution, expressed as a combination of Bessel’s functions, allows for the creation of a fast robust semi-analytical algorithm to compute the Green function in tubular structures. A model to approximate numerical defects is then developed. The defect response is considered as the cumulative response of secondary sources, aiming to negate the incident and diffracted stress field present within it. Next, the numerical model is validated with experimental measurements.Finally, the technique of Topological Imaging is introduced. This method of imaging is based on the idea of performing a correlation between two wave fields for defect localization. The versatility and flexibility of the numerical tool in conjunction with the method of imaging is then successfully demonstrated by localising and imaging a multitude of numerical and experimental defects with dimensions as low as 1=40th of the wavelength
Ahmad, Adeel. "Contribution à la multi-modélisation des applications distribuées pour le contrôle de l'évolution des logiciels." Thesis, Littoral, 2011. http://www.theses.fr/2011DUNK0387/document.
The software evolution control requires a complete understanding of the changes and their impact on the various systems artifacts. We propose a multi-modeling approach for the change impact analysis to provide assistance in understanding the effects of projected or actual changes in distributed software systems. This work elaborate the modeling of software artifacts along with their various interdependencies to build a knowledge-based system, which allows, among others, an assistance for the software developers or maintenance engineers to establish an a priori evaluation of impact of changes. The model we develop integrates two major descriptions of software, at first, the underlying structural description that encompasses the levels of granularity and abstraction of software artifacts, and then the qualitative description designed to integrate the structural description. Initially, the formal models are designed separately for the respective descriptions, and then these are integrated for the objective to study the change impact and its potential propagation through the affected software artifacts. For a change, it is important to establish a qualitative assessment of its impact. The integrated modeling leads to a reasoning based on expert rules. The proposed model is being tested and validated through the development of a platform, implemented in the Eclipse environment
Orlik, Kelly. "Nouvelles céramiques piézoélectriques sans plomb pour des applications sonar ou de contrôle non destructif." Electronic Thesis or Diss., Valenciennes, Université Polytechnique Hauts-de-France, 2019. http://www.theses.fr/2019UPHF0010.
In this work barium titanate doped with calcium and zirconium (BCTZ), with the composition Ba₀⋅₈₅Ca₀⋅₁₅Ti₀⋅₉₀Zr₀⋅₁₀O₃, was synthesized by solid-state route. The aim of this work was to elaborate an optimized and reproducible synthesis and sintering procedure. Besides, the composition was slightly varied to find the best compromise between the Curie temperature and the electrical properties. A decrease of the zirconium amount in this material led to an improvement of the Curie temperature associated to a decrease of the electrical properties. A solubility limit of 20 %at for calcium in BCTZ was demonstrated. Solid-state route coupled with conventional sintering proved to be an efficient process to obtain BCTZ samples with good properties but it is an energy and time-consuming process. By using microwave heating, the sintering step duration could be drastically reduced. Higher converse piezoelectric constant (d₃₃*) was measured for samples obtained by this fast sintering method. Microwave heating was also tested both to synthesize and to sinter BCTZ. Samples with a 88 % relative density and a d₃₃ piezoelectric constant of 50 pC/N were obtained in only 90 minutes
Chaouch, Olfa. "Tomographie passive des ondes acoustiques : Prédiction et identification à partir du bruit ambiant." Thesis, Le Mans, 2016. http://www.theses.fr/2016LEMA1035/document.
The work presented is in the domain of SHM. An identification method based on the cross correlations functions between piezoelectric sensors was proposed and gave birth to two criterion of identification. The first is a visual criterion, it is based on the superposition of the envelopes of the cross correlation functions obtained by Hilbert transform for two configurations, the first is a defect free configuration of reference and the other is with defect.The second criterion is numerical; it is the mean of the differences between two envelopes. The performance of these criterions was tested first on an aluminum plate in free edges conditions, using a source located in space; the intensity of this source was not controlled. The results of the first experiment has certainly shown the sensitivity of these criterion to the appearance of defects despite the randomness of the source, but also highly sensitivity to changes in the position of the source was found. In the second experiment a source not localized in space was used, and the plate was in clamped edges conditions. The proposed criterions have been tested using a single frequency sine signal as a source first and using a white noise filtered signal secondly. With the proposed criterion, the defect was certainly identified; however, it remains to find a way to locate and to characterize the defect
Hoang, Huu Tinh. "Contrôle santé intégré passif par ondes élastiques guidées de tuyauteries pour applications nucléaires et pétrolières." Thesis, Valenciennes, Université Polytechnique Hauts-de-France, 2020. http://www.theses.fr/2020UPHF0023.
Structural Health Monitoring (SHM) consists in embedding sensors into a structure in order to monitor its health inreal time throughout its lifetime. The research works carried out in this thesis aimed at developing a new approachof SHM for the detection of corrosion/erosion in pipes. This manuscript presents a new quantitative imaging method,called passive elastic guided wave tomography, based on the use of an embedded network of piezoelectric sensors(PZT) listening and analyzing only the ambient elastic noise which is naturally generated by the fluid circulation inpipes. This passive method offers many advantages for a SHM system, such as reduction of energy consumption,simplified electronics and ability to perform an inspection while the structure is in operation. In addition, thispassive method makes SHM systems possible to use Fiber Bragg Grating sensors (FBG) which have several advantagesover traditional PZT sensors (low intrusivity, resistance to harsh environments, etc.) but which are not able to emitwaves. A first demonstration of the feasibility of corrosion/erosion imaging by FBG is illustrated experimentallythanks to a result obtained by hybrid tomography in which wave emission is performed by PZT and reception byFBG. All these works offer promising perspectives for the application of passive tomography on industrial structuresusing a pure FBG system. Among the various results presented in this thesis, we also show that corrosion/erosiondefects can be characterized by tomography on a straight pipe without the need for a baseline measurement in apristine state. It is feasible by using a new method of auto-calibration of the data used for tomography. The absenceof baseline measurement makes the method very reliable and avoid false alarms of the system. Finally, preliminarystudies on tomography for more complex structures such as a bended pipe have been realized and validated throughsimulations
Huang, Xu-Dong. "Middle-Late Jurassic Cu-Pb-Zn-bearing and W-bearing granitoids and their skarn mineralization in the Nanling Range, South China : the Tongshanling and Weijia deposits." Thesis, Orléans, 2018. http://www.theses.fr/2018ORLE2038/document.
The Middle-Late Jurassic Cu-Pb-Zn-bearing and W-bearing granitoids in the Nanling Range were mainlyderived from non-simultaneous partial melting of the mafic amphibolitic rocks in the lower crust and themuscovite-rich metasedimentary rocks in the upper-middle crust, respectively. The fertile sources in theNanling Range are beneficial to the formation of Cu-Pb-Zn and W deposits during Middle-Late Jurassic.The lower-crust origin of the Cu-Pb-Zn-bearing granodiorites is further demonstrated by the dioriticmicrogranular enclaves in the Tongshanling granodiorite which are reworked restite enclaves derivedfrom partial melting of the mafic amphibolitic source. The Cu and Zn associated with these intrusionswere most probably released from the mafic amphibolitic lower crust by partial melting, whereas, Pb wasextracted from the upper crust by ascending granodioritic magmas. The emplacement of these orebearinggranitoid magmas may have a structural connection with the subsequent polymetallicmineralization in some way. For instance, the exoskarn and sulfide-quartz veins in the Tongshanling Cu-Pb-Zn deposit are evidently controlled by magma emplacement-induced wall-rock deformation. Thedifferent mineralization types and ore deposits in the Tongshanling Cu-Mo-Pb-Zn-Ag ore district aregenetically linked together in the same skarn system as the productions of evolution and zonation. TheWeijia granite was crystallized from a F-rich and water-saturated magma. The key factors controlling theoccurrence of unusual magnesian skarn W mineralization during Late Jurassic in the Nanling Rangemainly include a W enriched metasedimentary source, a fluorine-rich magma, a strong crystalfractionation, and a fluorine-rich hydrosaline melt
Wu, Dan. "Piezoelective semi-active networks for structural vibration damping with energy redistribution." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0078/document.
Structural vibration control is an important issue and has received considerable research attention in many industry applications. Researches investigated various approaches to reduce undesirable vibrations. The smart materials can control and suppress vibration in an efficient and “intelligent” way without causing much additional weight. The majority of research in smart damping materials has focused on the control of composite structure using embedded or bonded piezoelectric transducers. The advantages of piezoelectric materials include high achievable bandwidth, compactness, lightness, easy implementation and good electromechanical coupling characteristics, thus making them appropriate for actuators and sensors applications. Recently, a non-linear semi-passive vibration control technique, so-called Synchronized Switch Damping (SSD), has been developed. SSD technique relies on a cumulative build-up of the voltage resulting from the continuous switching of the piezoelectric voltage and it was shown that the performance is strongly related to this total voltage amplitude available. Based on SSD techniques, a new global approach for improved vibration damping of smart structure, based on global energy redistribution by means of a network of piezoelectric elements is proposed in this thesis. The objective of this work is to propose a new approach to increase the piezoelectric voltage (also related to the damping operative energy) in order to improve the damping performance. In the proposed semi-active approach, the extra energy used to improve this voltage is gathered on the various modes of the structure using an interconnected piezoelectric element network. Two original network topologies are developed for transferring energy. One is named SSDT for “Synchronized Switch Damping by energy Transfer”. The second is defined as SSDD for “Synchronized Switch Damping with Diode”. Performance evaluations and comparisons are performed on a model representative of a clamped plate equipped with piezoelectric elements in the case of multimodal motion. Compared to the Modal-SSDI method used as a baseline, simulation results and a global theoretical model are proposed demonstrating the relationship between the achievable damping improvement and the ratio of transferred energy to the structure mechanical energy, thus proving the capability of a network of piezoelectric elements for global energy management and redistribution in order to improve the vibration damping of smart structures
Sahyoun, Wafaa. "Maîtrise de l'aptitude de matériaux agro-alimentaires aux procédés de séchage : étude de l'adéquation entre les états structuraux, biochimiques, physiques et comportementaux sur les processus de déshydratation." Compiègne, 1996. http://www.theses.fr/1996COMPD900.
The natural structure of vegetables does not promote water transfer within raw products; this structure should be altered in order to enhance both drying and rehydration processes. This thesis aims at the determination, the quantifying, and the study of the modifications induced within the vegetable product (e. G. Carrot) following several pre-treatments: blanching, freezing, DIC and enzymic. Multidimensional approach has thus been performed; it has mainly been concerned with the structural analysis, the biochemical composition, and the physical characterisation, as well as their evolution. The study of the impact of these pre-treatments on drying and rehydration processes will not only permit to establish corrélations between the different approaches undertaken, but will more importantly better approach possible industrial applications. The study has revealed a positive impact induced by all pre-treatments considered on the drying time réduction. In all considered cases, with the exception of enzymic pre-treatment, a close correlation between drying time reduction, rehydration capacity enhancement, and the lowering of the product's density, has been observed. Furthermore, the evolution of water activity following the different pre-treatments, does not permit to explain the evolution of drying time. A positive impact of the different pre-treatments has systematically been observed in the preservation of lipids and provitamin A. All of the microscopie study has allowed to ascertain the huge impact of the modification of the structure on the behavioural properties of the products. The industrial application consists on the definition of a new process coupling the vacuum drying with a pre-treatment operation. The fundamental study thus realised allowed to choose freezing or DIC