Dissertations / Theses on the topic 'Simulation macroscopique'
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BOUSQUET, MELOU PATRICK. "Modelisation macroscopique et simulation numerique de la solidification des melanges binaires." Paris 6, 2000. http://www.theses.fr/2000PA066067.
Le, lan Jean-Vincent. "Etude de méthodes simplifiées pour la simulation de l'usinage à l'échelle macroscopique." Paris, ENSAM, 2007. https://pastel.archives-ouvertes.fr/pastel-00003289.
This work presents some simplified methods for machining simulation. Two main phenomena are studied, the form error and chatter prediction. For both studies the workpiece and the tool are modelized using a finite element model. The material cutting is modelized using an experimental cutting force law. The resulting cutting force is applied on models as a punctual loading. In order to predict the form error, the relative displacement between the tool and the workpiece is computed for each loading configuration. Then the final form error is built using these results. Regenerative effects are not taken into account. The study of the cutting instability is done appart. Chatter-relative methods are using a frequency domain approach to compute the inconditionnally stable depth of cut. For both aspects, a method based on the static behaviour of the system is presented first. Then, dynamic-based methods are presented. Computed results are confronted to experiments
Leclere, Guillaume. "Simulation numérique de la rupture dynamique de structures métalliques à l'échelle macroscopique." Nantes, 2004. http://www.theses.fr/2004NANT2118.
Azoug, Aurélie. "Micromécanismes et comportement macroscopique d'un élastomère fortement chargé." Phd thesis, Ecole Polytechnique X, 2010. http://tel.archives-ouvertes.fr/tel-00552234.
Cohen, Assouline Stéphanie. "Simulation numérique de l'usinage à l'échelle macroscopique : prise en compte d'une pièce déformable." Phd thesis, Paris, ENSAM, 2005. http://tel.archives-ouvertes.fr/tel-00012006.
Le principal apport de ce travail est la prise en compte de pièces dont la zone concernée par l'usinage est flexible. Cette présence de déformations dans la pièce a nécessité une définition précise de l'enlèvement de matière. Cette définition se fonde sur une configuration dite matérielle, où la réalisation pratique de la simulation de l'usinage est effectuée.
Par ailleurs, les pièces flexibles étant généralement très minces, l'enlèvement de matière peut modifier de façon significative le comportement dynamique de la pièce (perte de masse et de raideur). Pour être fidèle, une simulation doit alors prendre en compte cette modification de façon régulière en cours d'usinage. Nous montrons que cette prise en compte ne peut dans certains cas être évitée, et nous proposons une stratégie limitant les coûts numériques induits par cette prise en compte.
Un autre apport du travail réalisé est l'utilisation d'un modèle géométrique différent de celui des approches précédentes du LMSP, pour représenter le volume occupé par la pièce. Avec le modèle géométrique de la pièce retenu dans les travaux précédents du LMSP (modèle B-Rep analogue aux modèles utilisés en CAO), de très nombreuses intersections de polyèdres conduisent à des facettes "dégénérées" dont la prise en compte dans les algorithmes d'intersection est loin d'être triviale et constitue actuellement un des points bloquants pour ce qui concerne la robustesse. La nouvelle technique adoptée est celle des Z-buffer où la pièce est modélisée par des dexels (ensemble de « bâtonnets » disposés sur une matrice régulière). Cette description permet de simplifier sensiblement les algorithmes d'intersection tout en les rendant plus robustes. Cette nouvelle description nous a conduit à revoir la démarche de modélisation de l'interaction outil/pièce et notamment la démarche de calcul des efforts de coupe. Cette modélisation s'intègre dans le logiciel Nessy du LMSP. Par les résultats obtenus, nous démontrons la faisabilité de notre approche et son potentiel d'analyse.
Beauchesne, Erwan. "Simulation numérique de l'usinage à l'échelle macroscopique : prise en compte d'une pièce déformable." Paris, ENSAM, 1999. http://www.theses.fr/1999ENAM0033.
Mayet, Clément. "Simulation énergétique flexible d’un carrousel de métros basée sur la représentation énergétique macroscopique." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10013/document.
Transportation systems have to be efficient in terms of energy in order to limit their environmental impact. Electric public transportation, such as subways or tramways, is thus strongly requested in urban areas. Various innovative solutions have emerged recently to increase their energy efficiency (energy storage systems, reversible traction power substations, etc.). However, due to the complexity of the development and optimization of such systems, numerical simulation tools are essential. Nevertheless, simulators of railway systems are particularly delicate to develop due to non-linearity (non-reversibility of traction power substations), non-stationary (displacement of trains), and multiple energetic interactions which exists within these kind of systems. This PhD thesis then proposes a new simulation tool of subway system based on EMR formalism (Energetic Macroscopic Representation). This formalism structures the models according to the energetic properties of the system. It leads to a forward simulation approach with exclusive use of the integral causality. In that way, the proposed simulation tool is stemming from an innovative approach and allows a new vision of subway systems. These approaches allow especially the increasing of the simulator flexibility and the obtaining of physical simulation results. Moreover, this PhD thesis has the particularity to experimentally validate all the developed models
Dubacq, Benoît. "Thermodynamique des phyllosilicates de basse température : de l'approche macroscopique à la simulation atomistique." Phd thesis, Grenoble 1, 2008. http://www.theses.fr/2008GRE10265.
Phyllosilicates are important minerals in metamorphic petrology as well as in waste storage sites where clays are extensively used. Despite this fact, there is no thermodynamic model allowing to describe and to predict properly the behaviour of clay minerals (for example variation of volume with dehydration) and their phase relations with other minerals in metamorphic conditions. Inversely, the thermodynamic models of phengites are well constrained at high pressure and temperature but do not allow accurate thermobarometric estimations at temperatures less than about 350°C. In this study, we propose two new thermodynamic models for smectites, illites, mixed-layers illites / smectites and phengites. With these models, it is possible to predict the composition of stable clays at low temperature and to estimate the pressure and temperature of crystallisation of dioctahedral aluminous phyllosilicates. These models take into consideration the hydration state of clay minerals as a function of pressure, temperature and water activity. The thermodynamic properties of solid solutions and hydrated mica-like end-members have been estimated in order to reproduce experimental results of i) clay dehydration, ii) nature of stable phases, iii) calorimetric measurements, as well as known (or estimated with independent methods) pressure-temperature conditions of crystallization of phyllosilicates analyses, from diagenesis conditions to ultra - high - pressure / temperature conditions. Phase diagrams have been computed with these models in simple systems. Conditions of crystallization of phyllosilicates have been estimated on many samples, including electron microprobe compositional maps. We investigated several approaches to estimate thermodynamic properties of minerals. All these methods revealed to be insufficiently accurate to estimate standard enthalpy of formation; calculated enthalpies of formation can not be directly used for thermobarometric estimations. However, we suggest several improvements to these methods. We used atomistic simulation to calculate the mixing enthalpy along two solid solutions binaries of interest in low-temperature petrology. Results are in agreement with observations in natural systems and confirm the importance of hydration in clay minerals stability
Dubacq, Benoît. "Thermodynamique des phyllosilicates de basse température : de l'approche macroscopique à la simulation atomistique." Phd thesis, Université Joseph Fourier (Grenoble), 2008. http://tel.archives-ouvertes.fr/tel-00411810.
Nous proposons deux modèles thermodynamiques pour les smectites, illites, interstratifiés illites / smectites et micas. Ces modèles permettent respectivement de calculer la composition des phases stables à basse température, incluant les argiles, et l'estimation thermobarométrique de leurs conditions de cristallisation. Ils prennent tous deux en compte l'hydratation des phyllosilicates, variable en fonction de la composition, la pression, la température et l'activité d'eau. L'évaluation des propriétés thermodynamiques des équivalents hydratés des pôles purs des micas et des paramètres de solution solide nécessaires a été réalisée pour reproduire au mieux les contraintes expérimentales de déshydratation, nature des phases stables, calorimétrie ainsi que les estimations des conditions de cristallisation d'une compilation d'analyses, dont la gamme s'étend de la diagenèse à la haute pression - haute température. Ces modèles sont appliqués au calcul de diagramme de phase dans des systèmes chimiques simples et à l'estimation des conditions de cristallisation de phyllosilicates de nombreux échantillons naturels, y compris à partir de cartographies élémentaires.
Nous avons testé plusieurs méthodes d'estimation des propriétés thermodynamiques des phases pour lesquelles les contraintes expérimentales et / ou du milieu naturel sont insuffisantes. Aucune d'entre elles ne permet une estimation de l'enthalpie standard de formation directement utilisable à des fins thermobarométriques. Nous proposons cependant une approche pour améliorer cette situation. De plus, nous avons utilisé une méthode de simulation atomistique pour évaluer l'enthalpie de mélange le long de deux solutions solides d'intérêt pour la pétrologie de basse température. Les résultats sont compatibles avec les observations du milieu naturel, et le calcul du solvus entre les pôles muscovite et pyrophyllite confirme l'importance de l'hydratation pour la stabilité des argiles.
Kostenko, Romaric. "Simulation d'écoulements non-newtoniens en milieu poreux macroscopique par la méthode de lattice-Boltzmann." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS561.
A non-newtonian fluid is a fluid which relation between it's shear rate and the stress under which it is put, is not linear. In a porous medium, the stress imposed to the fluid depends on the imposed pressure, but also on the pores size, and therefore on the macroscopic scale permeability. Some fluids have a rheology such that the fluid show a change of behaviour reaching a yield stress. If the pore size is random, then the fluid will present heterogeneous regime changes in the medium. The flow will then show a first regime where the whole fluid will be under the threshold, a regime where the whole fluid will be far above the threshold, and an intermediate regime for which both rheologies coexists. We are interested in intermediate regime for the flow of non-newtonian fluids in macroscopic porous media, and study it with numerical simulations. More particularly, we look at the flow of a Bingham fluid and that of a Carreau fluid. The Bingham fluid doesn't flow under a yield stress. Under the threshold, it behaves as a solid. Beyond, it's shear-rate/stress relation is an affine law. Carreau fluids have a shear-rate/stress relation that change regime between that of a newtonian fluid, and a power law. The macroscopic scale study is done simulating a Darcy-Brinkman law in a heterogeneous permeability field. We use for our simulations the lattice-Boltzmann method, on a regular node grid, and more specifically Irina Ginzburg two relaxation-time scheme. For each fluid, we study the flow-pressure relationship, as well as the geometric properties and the multi-scale properties in the fluid regions in the same flow regime (clusters), properties such as their size and shape. We also link these geometrical properties to the percolation theory, which studies the behaviour of randomly opening node maps and predicts fractal properties
Simo, Kanmeugne Patrick. "Simulation crédible des déplacements de piétons en temps réel : modèle microscopique à influence macroscopique." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://tel.archives-ouvertes.fr/tel-01066477.
Simo, Kanmeugne Patrick. "Simulation crédible des déplacements de piétons en temps réel : modèle microscopique à influence macroscopique." Electronic Thesis or Diss., Paris 6, 2014. http://www.theses.fr/2014PA066597.
In this work, we focus on real-time simulation of autonomous pedestrians navigation. Existing models for this purpose tend to diverge on whether to build on pedestrians' characteristics and local interactions - microscopic approaches - or to focus on pedestrians' flow regardless of individual characteristics - macroscopic approaches. Our position is that the two approaches should not be separated. Thus, we introduce a Macroscopic-Influenced Microscopic approach which aims at reducing the gap between microscopic and macroscopic approaches by providing credible walking paths for a potentially highly congested crowd of autonomous pedestrians. Our approach originates from a least-effort formulation of the navigation task, which allows us to consistently account for congestion at every levels of decision. We use the multi-agent paradigm and describe pedestrians as autonomous and situated agents who plan dynamically for energy efficient paths, and interact with each other through the environment. The navigable space is considered as a set of contiguous resources that agents use to build their paths. We emulate the dynamic path computation for each agent with an evolutionary search algorithm that implement a tabu search heuristic, especially designed to be executed in real-time and autonomously. We have compared an implementation of our approach with a standard microscopic model, against low-density and high density scenarios, with encouraging results in terms of credibility and scalability. We believe that microscopic models could be easily extended to embrace our approach, thus providing richer simulations of potentially highly congested crowd of autonomous pedestrians
Ducourthial, Élodie. "Simulation et analyse de la propagation d'une fissure macroscopique dans un milieu élastique fragile microfissuré." Paris, ENMP, 2001. http://www.theses.fr/2001ENMP1041.
Ducourthial, Élodie. "Simulation et analyse de la propagation d'une fissure macroscopique dans un milieu élastique fragile microfissuré /." Châtillon : ONERA, 2001. http://catalogue.bnf.fr/ark:/12148/cb37686001t.
Tabti, Saïd. "Modélisation macroscopique de l'écoulement du trafic aérien : une approche par analyse de données multidimensionnelles." Lyon 1, 1999. http://www.theses.fr/1999LYO10055.
Dugois, Kévin. "Simulation à l’échelle microscopique et analyse macroscopique de l’imprégnation d’un matériau composite par un fluide chargé en particules." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0011/document.
In order to improve thermo-mechanical behavior of tubine blades in SAFRAN engines plane, a new composite material is necessary. The manufacturing process to obtain this composite is intricate and requires a two steps fluid densification process. This thesis focuses on numerical simulation of the first one called Slurry Cats/APS. In this step, suspended particles are introducted and captured in the reinforcement. For that purpose,we carry out a model at fiber scale, using Navier-Stokes equations in incompressible and monophasic formulation, Phillips equations [Phillips et al., 1992] and a rheological law [Krieger, 1972]. After validation step consisting in a comparison of computational results with experiments [Hampton et al., 1997] and theorical law [Belfort et al., 1994], this model has been used to simulate flow around geometries similar to those encountered in our composite material
Marty, Audrey. "Simulation numérique de l'usinage par outil coupant à l'échelle macroscopique : contribution à la définition géométrique de la surface usinée." Phd thesis, Paris, ENSAM, 2003. http://tel.archives-ouvertes.fr/tel-00005762.
Le premier objectif a alors été de revenir à un cas simple : le tournage en coupe orthogonale. Ceci a permis de vérifier à nouveau la pertinence de notre démarche et de commencer l'analyse des algorithmes d'intersection par celle d'un cas simplifié. Un simulateur spécifique a été mis en place et des comparaisons avec des résultats expérimentaux sont montrées.
Le second objectif a été d'améliorer l'algorithme d'intersection dans le cas tridimensionnel en reprenant complètement les points de vue adoptés dans les travaux précédents du LMSP. Le travail d'intersection est maintenant effectué dans une configuration de référence matérielle de la pièce. Ceci, combiné à une analyse autorisant l'auto-intersection d'un modèle B-Rep, améliore la robustesse générale de l'algorithme. Les développements correspondants à ce travail ont été intégrés dans le logiciel Nessy du LMSP.
Castaings, Ali. "Gestion d’énergie de véhicules multi-sources électriques et hybrides au travers de la représentation énergétique macroscopique." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10025/document.
Road vehicles are at a turning point of their history. In order to face economic and environmental challenges, road vehicle of the future must be less energy-consuming and less polluting. Multi sources vehicles represent interesting solutions in order to comply with these challenges. However, these vehicles use particularly complex propulsion systems, both on the architecture level and the control level. The management of the different energy sources represents a key issue for the energy efficiency of the vehicles to be designed. It becomes a real challenge as soon as one exceeds the usual number of two sources, as in current hybrid vehicles and mixed electric vehicles (battery and supercapacitors). The objective of the works relative to this thesis is to propose a structured method for the synthesis the energy management in real time, of electric or hybrid multi-sources vehicles. This approach is based on a systemic approach using the modeling and Energetic Macroscopic Representation (EMR) as a tool of assistance to the synthesis of the models and the related control. A systematic way for the synthesis of the strategies based on optimal control, has been associated benefitting from EMR tool. Indeed, EMR respecting “physical” causality (integral causality) on the one hand, and giving a clear distinction between the control level known as “local” and the “strategy” level on the other hand, the formulation of the optimal control problem is carried out and efficiently structured. Thus, on the basis of the electric vehicle case with a multi-source system battery/supercapacitors already studied in the literature, the method was applied for the synthesis of an energy management law based on the optimal control. Then, sources were added to pass to the case of three sources by including a Fuel cell, then four sources by adding a generator set. The developed principles are validated by simulation and experimental tests, in order to assess the feasibility in real time of the developed strategies
El, Mayas Theet Nathalie. "Modélisation microscopique et macroscopique du comportement d'un composite à matrice métallique." Phd thesis, Ecole Nationale des Ponts et Chaussées, 1994. http://tel.archives-ouvertes.fr/tel-00523623.
Agha, Mohammadi Farahnaz. "Contribution à la modélisation éléctrique et électromagnétique des circuits électroniques microondes basée sur une approche physique macroscopique dans le domaine temporel." Lille 1, 1998. http://www.theses.fr/1998LIL1A001.
El, Mayas Theet Nathalie. "Modélisation microscopique et macroscopique du comportement d'un composite à matrice métallique." Phd thesis, Marne-la-vallée, ENPC, 1994. http://www.theses.fr/1994ENPC9402.
A thermoviscoplastic model is presented to characterize the macroscopic behavior of a Metal Matrix Composite (MMC) reinfored with short fibers. This analysis is based on experimental data and numerical results in order to build up the theoretical model. The experimental analysis is performed with cycling loadings and with tension-compression tests at several temperatures and for different material directions. It allows to observe the evolution of the elastic domain with temprature, time and plastic strain. The numerical analysis performed in viscoplasticity on a unit cell using the Finite Element Method (FEM), gives informations about the residual stresses and plasticity in the material after the manufactoring thermal process. The macroscopic response is then studied for different loading paths. The theorerical model is based on homogenization techniques like the homogenization of a periodic media, the self consistent method and the transformation concentration factor tensors developed by Dvorak. These methods allows the correlate to overall and local mechanical variables together. A simplified version degenerates into a purely macroscopic constitutive model. The macroscopic constitutive equations in thermo-elasto-viscoplasticity are based on a non-linear kinematic hardening and takes into account, on one hand, the effects and the evolution of the initial back stress and, on the second hand, the initial anisotropy of the material and its evolution during a viscoplastic flow
Combe, Gaël. "Origines géométriques du comportement quasi-statique des assemblages granulaires denses: étude par simulation numérique." Phd thesis, Ecole des Ponts ParisTech, 2001. http://tel.archives-ouvertes.fr/tel-00005737.
Combe, Gaël. "Origines géométriques du comportement quasi-statique des assemblages granulaires denses : étude par simulations numériques." Marne-la-vallée, ENPC, 2001. http://www.theses.fr/2001ENPC0015.
Bendhaou, Wafa. "Modélisation macroscopique des écoulements à masse volumique variable : vers un modèle de la pyrolyse de la biomasse." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLC084.
Pyrolysis is a thermo-chemical conversion of biomass into bio-fuels. This technology has not been fully developed and its competitiveness against other sources of energy is yet to be proven. The aim of this work is to derive a macroscopic model of pyrolysis by means of volume averaging method. The obtained macroscopic model can then be used to conduct fast and low-cost numerical simulations to characterize the process and improve the reactor efficiency. To achieve our objective, a two-steps methodology has been established. First, the fundamental problem of variable density flow in porous media has been investigated. The physical phenomena in this kind of problem are very similar to those involved in pyrolysis for two reasons: the fluid density varies due to high temperature gradients and the pyrolysis reactor can be considered as a double porosity medium (porosity at the reactor scale and porosity at the biomass particle scale). The obtained macroscopic conservation equations (continuity, momentum and energy) and the effective properties (density, permeability and thermal diffusivity) contain additional terms resulting from the fluid density variation. The explicit form of these terms has been established and their components have been computed. The resulting models of the first step have then been used to develop a macroscopic model of the pyrolysis in the second part of our study
Pam, Abdoulaye. "Méthodologie d’émulation pour le test de chaîne de puissance de véhicules électrifiés." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I027.
The electrification of transportation has become, for several years, an essential solution to deal with the various ecological problems in transport. Thus, electrified vehicles (hybrid and electric) are more and more put on the road. Test procedures for their various components are organized to optimize the design, production, and quality of these vehicles. Power Hardware-in-the-Loop simulation (using power emulators) has become an important step in the vehicle development cycle for these various tests. To reduce time and cost constraints, the rapid development of reliable and flexible power emulators is necessary. The objective of this PhD thesis is to propose a method for the design of power emulators for electrified vehicles for the testing of their various functional subsystems. EMR (Energetic Macroscopic Representation) formalism is used as an organization tool for the design of the various power emulators. The methodology developed is used to test the battery and electric drives of a series hybrid electric vehicle. First, a unified representation of the energetic simulation model of the series hybrid electric vehicle is proposed. Next, the methodology is applied for the battery testing of the reference vehicle. Finally, the methodology is applied for electric drives testing. Experimental results are provided throughout this PhD thesis to validate these various power emulators
Desreveaux, Anatole. "Impact de facteurs techniques sur la consommation énergétique de véhicules électriques." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I004.
Global Warning is one of the major challenges for the 21st century. The transport sector is one of the biggest emitters of greenhouse gas. Electric Vehicles (EVs) are one of the solutions able to reduce those emissions. However, the driving range of the vehicle is one of the barriers for EVs’ adoption. The Campus of University with Mobility based on Innovation and carbon Neutral (CUMIN) program aims at reducing the greenhouse gas emissions produced by mobility at campus “Cité Scientifique” of the University of Lille. EVs are one of the solutions studied to reduce emissions on this campus. For this solution, the university wishes to study the implementation of charging stations to promote EVs. In order to do this, a tool for estimating the energy consumption of an EV is required.Many factors have an impact on the energy consumption of EVs or their driving range. It is necessary to evaluate the effects of the different factors so as to have a better estimation of the driving ranges of those cars. In this PhD Thesis, the impact of different factors on the energy consumption of an Electric Vehicle has been assessed with a simulation tool developed on purpose. The suggested tool takes into account the energy consumption of the traction system, the Heating, Ventilation and Air Conditioning (HVAC) system and the other auxiliaries of the vehicle. This tool has been developed with Energetic Macroscopic Representation. This formalism aims at organizing the model using a forward approach. With this approach, it is possible to take into account the limitations of the system in the simulation tool of the vehicle. In this thesis, the modeling of the different parts have been developed, then validated with experimental tests. Finally, simulations have been carried out to evaluate the impact of the different factors on the energy consumption of an EV
Nguyen, Bao Huy. "Stratégies de gestion d’énergie pour véhicules électriques et hybride avec systèmes hybride de stockage d’énergie." Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1I045/document.
Electric and hybrid vehicles are among the keys to solve the problems of global warming and exhausted fossil fuel resources in transportation sector. Due to the limits of energy sources and energy converters in terms of power and energy, hybridizations are of interest for future electrified vehicles. Two typical hybridizations are studied in this thesis: • hybrid energy storage subsystem combining batteries and supercapacitors (SCs); and• hybrid traction subsystem combining internal combustion engine and electric drive. Such combined energy sources and converters must be handled by energy management strategies (EMSs). In which, optimization-based methods are of interest due to their high performance. Nonetheless, these methods are often complicated and computation consuming which can be difficult to be realized in real-world applications.The objective of this thesis is to develop simple but effective real-time optimization-based EMSs for an electric car and a parallel hybrid truck supplied by batteries and SCs. The complexities of the studied system are tackled by using Energetic Macroscopic Representation (EMR) which helps to conduct reduced models for energy management at the supervisory level. Optimal control theory is then applied to these reduced models to accomplish real-time EMSs. These strategies are simple due to the suitable model reductions but systematic and high-performance due to the optimization-based methods. The performances of the proposed strategies are verified via simulations by comparing with off-line optimal benchmark deduced by dynamic programming. Moreover, real-time capabilities of these novel EMSs are validated via experiments by using reduced-scale power hardware-in-the-loop simulation. The results confirm the advantages of the proposed strategies developed by the unified approach in the thesis
Soussi, Hakim. "Modèle global et paramétrable, pour la gestion des foules d'agents en animation comportementale." Phd thesis, Université de Bourgogne, 2011. http://tel.archives-ouvertes.fr/tel-00762319.
Tournez, Florian. "Du composant au conducteur dans la boucle de simulation pour le test de véhicules électriques hybrides." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILN060.
Vehicle electrification plays a crucial role in the fight against climate change. In response to the increasingly pronounced growth of electrified vehicles in the global automotive market, new technologies have emerged to meet the demand. Hardware-in-the-Loop simulations, such as Signal (S-HIL) and Power (P-HIL), are already used in the automotive industry to test various components and next-generation subsystems before their integration into the final prototype, but their potential remains underutilized. To promote their use and enhance the speed of development, new and affordable methods need to be implemented.The objective of this thesis is to propose a flexible method for testing various electrical subsystems, ranging from traditional HIL simulations to Driver-in-the-Loop simulation (DIL). The concept of distributed HIL simulation is based on the use of a remote server. The remote server corresponds to a virtual computer located in a data center equipped with the Amesim Simcenter simulation software. The software provides access to an online library of models, allowing the user to couple their models or locally located subsystems with Amesim Simcenter to perform pure simulations, S-HIL, or P-HIL. A simple and flexible interface has been established through the organization of models using the Energetic Macroscopic Representation (EMR) formalism. Distributed HIL simulation was carried out as part of the H2020 PANDA Project to improve the integration of electrified vehicles into the automotive market. The second focus is to implement a DIL simulation coupled simultaneously with a P-HIL simulation while retaining the flexibility of using models in a real-time simulation platform. This approach enables the testing of a power subsystem while incorporating a driver through a driving simulator (DIL/P-HIL)
Pauthenet, Martin. "Macroscopic model and numerical simulation of elastic canopy flows." Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0072/document.
We study the turbulent flow of a fluid over a canopy, that we model as a deformable porous medium. This porous medium is more precisely a carpet of fibres that bend under the hydrodynamic load, hence initiating a fluid-structure coupling at the scale of a fibre's height (honami). The objective of the thesis is to develop a macroscopic model of this fluid-structure interaction in order to perform numerical simulations of this process. The volume averaging method is implemented to describe the large scales of the flow and their interaction with the deformable porous medium. An hybrid approach is followed due to the non-local nature of the solid phase; While the large scales of the flow are described within an Eulerian frame by applying the method of volume averaging, a Lagrangian approach is proposed to describe the ensemble of fibres. The interface between the free-flow and the porous medium is handle with a One-Domain- Approach, which we justify with the theoretical development of a mass- and momentum- balance at the fluid/porous interface. This hybrid model is then implemented in a parallel code written in C$++$, based on a fluid- solver available from the \openfoam CFD toolbox. Some preliminary results show the ability of this approach to simulate a honami within a reasonable computational cost. Prior to implementing a macroscopic model, insight into the small-scale is required. Two specific aspects of the small-scale are therefore studied in details; The first development deals with the inertial deviation from Darcy's law. A geometrical parameter is proposed to describe the effect of inertia on Darcy's law, depending on the shape of the microstructure of the porous medium. This topological parameter is shown to efficiently characterize inertia effects on a diversity of tested microstructures. An asymptotic filtration law is then derived from the closure problem arising from the volume averaging method, proposing a new framework to understand the relationship between the effect of inertia on the macroscopic fluid-solid force and the topology of the microstructure of the porous medium. A second research axis is then investigated. As we deal with a deformable porous medium, we study the effect of the pore-scale fluid-structure interaction on the filtration law as the flow within the pores is unsteady, inducing time-dependent fluidstresses on the solid- phase. For that purpose, we implement pore-scale numerical simulations of unsteady flows within deformable pores, focusing for this preliminary study on a model porous medium. Owing to the large displacements of the solid phase, an immersed boundary approach is implemented. Two different numerical methods are compared to apply the no-slip condition at the fluid-solid interface: a diffuse interface approach and a sharp interface approach. The objective is to find the proper method to afford acceptable computational time and a good reliability of the results. The comparison allows a cross-validation of the numerical results, as the two methods compare well for our cases. This numerical campaign shows that the pore-scale deformation has a significant impact on the pressure drop at the macroscopic scale. Some fundamental issues are then discussed, such as the size of a representative computational domain or the form of macroscopic equations to describe the momentum transport within a soft deformable porous medium
Wang, Jie. "Simulation macro-méso de la mise en forme de renforts tissés interlocks." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI075.
The forming stage in the RTM process is crucial because it strongly influences the mechanical behavior of composites in service. In order to better predict the appearance of possible defects of composite materials, numerical simulations are increasingly developed taking into account the duration and the cost of experiences. Deformations and orientations of yarns at the mesoscopic scale are essential to simulate the resin flow in the stage of injection. Given the number of elements and their complex interactions, it is difficult to conduct the shaping simulations for the entire reinforcement at this mesoscopic scale. This present thesis consists in developing a multiscale method that allows linking the macroscopic simulations of reinforcements and the mesoscopic modellings of RVE (representative volume element) during the forming process. Firstly, the numerical simulations for three different woven reinforcements at the macroscopic scale are carried out using an anisotropic hyperelastic constitutive law, by the finite element method with a dynamic explicit scheme. Then, the geometrical modelling of RVE at the mesoscopic scale are reconstituted based on the tomographic images. The mesoscopic displacement-deformation fields of woven reinforcements are determined from the macroscopic results and the position of the yarns. In order to take into consideration sliding effects of yarns, two approaches of mesoscopic simulations of RVE are developed. Finally, the mesoscopic numerical results are compared with the experimental results
Torres, Guzman Diana Angélica. "Generation and control of tactile feedback with longitudinal ultrasonic vibration and human-in-the-Loop analysis." Thesis, Université de Lille (2018-2021), 2021. http://www.theses.fr/2021LILUN035.
Haptic technology offers users a unique way of interacting with the virtual world, as it allows direct information transfer between the interfaces and the human through the sense of touch. Surface haptic devices use different techniques to achieve friction modulation in order to simulate texture. In the case of ultrasonic surface haptics, this is achieved with the use of piezoelectric ceramics, which, supplied by a sinusoidal alternating voltage, elicit motion on the surface of the device. This motion is transmitted and amplified by the material, at its resonance frequency.Transversal vibrational modes are commonly used in ultrasonic surface haptic technology. This work evaluates the possibility to use longitudinal vibration as a technological alternative to produce haptic return in ultrasonic devices. Valuable comparisons between transverse and longitudinal modes are performed on a dedicated device, both on the point of view of energetic behavior and stimuli perception quality. The action and perception of the human in this context are very important. Unfortunately, due to the complexity of friction phenomena, the sensory response is different from one user to another, with the same haptic stimulus. For this reason, it is interesting to explore the human in the tactile simulation loop. With this purpose in mind, an initial attempt to develop the concept of "Human-in-the-Loop" in surface haptics is given in this thesis, using the EMR formalism, (Energetic Macroscopic Representation)developed within the L2EP Control team and already commonly applied to HIL (Hardware in the Loop).This PhD thesis is organized as follows: chapter 1 presents the state of the art and the positioning. Chapter 2 presents the creation and control of a longitudinal wave surface haptic device. In Chapter 3, the interaction model at the origin of the friction modulation effect with ultrasonic longitudinal vibration is proposed and validated for the case where the exploration occurs in the same axis as the wave motion, as well as the more general case where the exploration occurs in any other direction. In Chapter 4, a series of experiments are conceived to perform a comparative analysis between longitudinal and transverse ultrasonic vibration, in terms of energetic requirements for a given texture intensity. From this study, it is possible to perceive one important problematic in the design of ultrasonic surface haptic devices: the adaptation of the haptic feedback to each user to achieve a standardized perception. Chapter 5 deals with this problematic, by introducing the concept of acoustic finger force and its correlation with the friction reduction phenomenon. Finally, Chapter 6 presents the lessons learned in the previous chapters in a ‘Human-in-the-loop’ perspective and explores the possible future applications of this type of analysis.This work has been carried out within the framework of the Mint Project at IRCICA. It takes, therefore, part in the collaborative ‘CRIStAL-L2EP-MINT’ team, and CNRS GdR TACT group
Orliac, Jean-Guillaume. "Analyse et simulation du comportement anisotrope lors de la mise en forme de renforts tissés interlock." Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00823359.
Liu, Yuchen. "Synthesis, structural characterization and electrochemical hydrogen storage properties of LaNi5 and La4MgNi19 alloys prepared by mechanical alloying." Electronic Thesis or Diss., Bourgogne Franche-Comté, 2024. http://www.theses.fr/2024UBFCA004.
Today's world is facing the imminent depletion of fossil fuels and serious environmental problems, and it is urgent to find clean and renewable energy sources. Hydrogen energy, as a clean energy source, is a potential candidate. In a hydrogen economy based on hydrogen energy, hydrogen storage is the biggest obstacle limiting its development. Metal hydrides have attracted attention due to their safety and high hydrogen storage properties. The first generation of commercial hydrogen storage alloy LaNi5-based alloy has excellent hydrogen storage performance and has been widely used in various fields. However, due to its low hydrogen storage capacity, it is difficult to meet the requires of the European Union for hydrogen storage materials. Scientists often use a single optimization method, such as element substitution, new synthetic routes, surface optimization, etc. However, few articles report optimization methods that combine the two methods.In this work, first principles were used to screen out the best element Cr to substitute Ni. Mechanical alloying was used to synthesize LaNi5 alloy and LaNi4Cr alloy. The micromorphology and phase composition of different samples produced with different ball milling parameters were characterized by SEM and XRD tests. The hydrogen storage performance of the sample was then tested, and the gaseous hydrogen storage performance and electrochemical performance of the sample were obtained. The hydrogen storage properties of all the above samples are compared with each other, and the results reflect the effectiveness of the combination of mechanical alloying and element substitution methods for the optimization of LaNi5.In addition, another optimization method of LaNi5 alloy was also carried out, that is, combining it with AB2 phase to form La4MgNi19 alloy. A total of 6 sets of parameters with different ball milling times and different precursors were used to synthesize La4MgNi19 alloy. The phase composition and hydrogen storage properties of all samples were obtained and compared with the hydrogen storage properties of LaNi4Cr. The results show that the hydrogen storage performance of La4MgNi19 alloy is better than that of LaNi5 alloy, but slightly worse than that of LaNi4Cr alloy.Finally, with the help of simulation software, the parameters of the LaNi4Cr alloy were introduced into the proven hydrogen storage tank model to explore the performance of this alloy in the hydrogen storage tank. After exploring the effects of different parameters on the hydrogen storage tank, water pipes were added to adjust the heat exchange. The results show that hydrogen storage tanks filled with LaNi4Cr have excellent performance
Du, Peloux de Saint Romain Bertrand. "Modélisation des actionneurs électromagnétiques par réseaux de réluctances : création d'un outil métier dédié au prédimensionnement par optimisation." Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10144.
In the field of electromagnetism, the reluctance networks are perfectly adapted to pre- sizing issues. However, their setting in equations is a tiresome task and often leads to errors, and suffers from a lack of dedicated. This work proposes to formulate this method in a general case, and then to implement it in a dedicated tool in order to automate the creation process of the model, starting from the designer's know-how. In order to improve the models, energies and force calculation are also proposed. Finally an automatic derivation of the model allows its compatibility with optimization algorithms that use the gradients. The simulation of the transient states is also approached through a methodology allowing to couple electric and mechanical parts, thus a complete dynamic model can be obtained. A close attention is paid to their formulation because of the integration of the differential equations by numerical methods
Aviziotis, Ioannis. "Chemical vapor deposition of Al, Fe and of the Al13Fe4 approximant intermetallic phase : experiments and multiscale simulations." Thesis, Toulouse, INPT, 2016. http://www.theses.fr/2016INPT0100/document.
Films containing intermetallic compounds exhibit properties and combination of properties which are only partially explored. They carry potential solutions to confer multifunctionality to advanced materials required by industrial sectors and to become a source of breakthrough and innovation.Metalorganic chemical vapor deposition (MOCVD) potentially allows conformal deposition on, and functionalization of complex surfaces, with high throughput and moderate cost. For this reason, it is necessary to control the complex chemical reactions and the transport mechanisms involved in a MOCVD process. In this perspective, computational modeling of the process, fed with experimental information from targeted deposition experiments, provides an integrated tool for the investigation and the understanding of the phenomena occurring at different length scales, from the macro- to the nanoscale. The MOCVD of Al-Fe intermetallic compounds is investigated in the present thesis as a paradigm of implementation of such a combined, experimental and theoretical approach. Processing of the approximant phase Al13Fe4 is particularly targeted, due to its potential interest as low-cost and environmentally benign alternative to noble metal catalysts in the chemical industry. The attainment of the targeted Al13Fe4 intermetallic phase passes through the investigation of the MOCVD of unary Al and Fe films. The MOCVD of Al from dimethylethylamine alane (DMEAA) in the range 139oC-241oC results in pure films. Increase of the deposition temperature yields higher film density and decreased roughness. The Aldeposition rate increases to a maximum of 15.5 nm/min at 185oC and then decreases. Macroscopic simulations of the process predictdeposition rates in sufficient agreement with experimental measurements, especially in the range 139oC-227oC. At higher temperatures, competitive gas phase and surface phenomena cannot be captured by the applied model. Multiscale modeling of the process predicts the RMS roughness of the films accurately, thus allowing the control of properties such as electrical resistivity which depend on the microstructure. The MOCVD of Fe from iron pentacarbonyl, Fe(CO)5, is investigated in the range 130oC-250oC for the possibility toobtain fairly pure Fe films with low Oand C contamination. The surface morphology depends strongly on the temperature and changes are observed above 200oC. The Fe deposition rate increases up to 200oC, to a maximum of 60 nm/min, and then decreases. Moreover, the deposition rate decreases sharply with increasing pressure. Computational predictions capture accurately the experimental behavior and they reveal that the decrease athigher temperatures and pressures is attributed to the high gas phase decomposition rate of the precursor and to inhibition of the surface fromCO. The multiscale model calculates RMS roughness in good agreement with experimental data, especially at higher temperatures. Upon investigation of the two processes, aseries of Al-Fe co-depositions performed at 200oC results in Al-rich films with a loose microstructure. They contain no intermetallic phases and they are O-contaminated due to the reaction of the Al with the carbonyl ligands. Sequential deposition of Al and Fe followed by in situ annealing at 575oC for 1 h is applied to bypass the Ocontamination. The process conditions of Fe are modified to 140oC, 40 Torr and 10 min resulting in O-free films with Al:Fe atomic ratio close to the targeted 13:4 one. Characterization techniques including X-ray diffraction, TEM and
Solano, Javier. "Modélisation et supervision des flux énergétiques à bord d'un véhicule hybride lourd : approche par logique floue de type-2." Phd thesis, Université de Franche-Comté, 2012. http://tel.archives-ouvertes.fr/tel-00699896.
Nouh, Aiman. "Contribution au développement d’un simulateur pour les véhicules électriques routiers." Besançon, 2008. http://www.theses.fr/2008BESA2013.
Since noise and polluting gases as well as fuel consumption rise steadily, the interest in electric vehicles (EV) is ever more increasing nowadays. The EV is one of the solutions recommended by vehicle manufacturers and research organizations, to gradually replace the conventional vehicles especially in city centres. In this context, the generic, quick and accurate numerical simulation proves to be the main means of designing more and more high-performing and competitive electric vehicles. Thus, this research work has the goal to develop a simulator dedicated to electric vehicles and called ELEctric Vehicle Simulator (ELEVES). It uses the Component Hybrid Dynamic Nets (CHDN) as a graphical formalism for extracting the system of equations. The advantage of ELEVES that it allows the user not only to build and simulate an EV from its pre-established libraries, but also to build his own models. A dynamic model of vehicle with three degrees of freedom, a model of a permanent magnets synchronous motor with its power supply have been implemented into ELEVES. In order to include the control aspect of EV, a systematic approach based on the Energetic Macroscopic Representation (EMR) has been adopted. Thus, starting from EMR, a Maximum Control Structure (MCS) has been established to control the EV speed. Finally, three architectures of EVs have been simulated to highlight some ELEVES’s capabilities and to show the necessary steps to follow for building such applications. They are the two in-wheel drives EV with and without speed control and the four in-wheel drives EV. In order to assess the validity of ELEVES, the same simulations have been performed using Matlab/Simulink, the results obtained from both softwares are in a good agreement
Callot, Stanislas. "Analyse des mécanismes macroscopiques produits par les interactions rotor/stator dans les turbomachines." Ecully, Ecole centrale de Lyon, 2002. http://bibli.ec-lyon.fr/exl-doc/scallot.pdf.
Unsteady phenomena produced by the relative motion between fixed and moving rows in turbomachinery is caracterized by different scales in space and time. From the numerical point of view, taking into account those effets requires new models. The purpose of this work is a better understanding of the unstaeday mechanisms in a multistage turbomachinery. In ordre to cast of any restricting hypothesis over the spatial periodicities, numerical simulations are operated over the whole circumference of each row. In the single stage case, it is shown that the unsteady flow presents a phase-lagged periodic condition which may be described by the double Fourier decomposition proposed by Tyler & Sofrin. The spatial modes precise the interaction between rows and a comparison is made with the Adamczyk's decomposition. The numerical simulation of a one and a half stage brings an extension of the analysis of the interactions in a multistage machine
Callot, Stanislas Ferrand Pascal. "Analyse des mécanismes macroscopiques produits par les interactions rotot/stator dans les turbomachines." Ecully : Ecole centrale de Lyon, 2002. http://bibli.ec-lyon.fr/exl-doc/scallot.pdf.
Solano, Martinez Javier Enrique. "Modélisation et supervision des flux énergétiques à bord d'un véhicule hybride lourd : approche par logique floue de type-2." Phd thesis, Université de Franche-Comté, 2012. http://tel.archives-ouvertes.fr/tel-00947626.
Monnier, Arnaud. "Interactions entre perturbations magnétiques macroscopiques et turbulence microscopique dans un modèle 3D d'un plasma de tokamak." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4773/document.
In this thesis, the interaction between tokamak edge plasma and resonant magnetic perturbation (RMPs) is studied. It is mainly used to mitigate quasi-periodic relaxations in enhanced confinement regime. This regime allows to obtain good conditions for nuclear fusion. Introduction of a RMP in a tokamak plasma has been observed to modified the magnetic topology at the edge and decrease the relaxation amplitude up to complete suppression. Previous works studied the RMP effect on a plasma with relaxations, via numerical simulations. The model used for that consider the electrostatic approximation, where the magnetic topology does not evolve in time. In this thesis, the study is done with an edge plasma model taking into account magnetic fluctuations via the numerical code EMEDGE3D. This code has been modified to include the resonant magnetic perturbation. Comparison with reduced models has been carried out on the RMP penetration and the effect of sheared velocity on it. Then a RMP has been induced in a stable plasma, with or without imposed sheared rotation. A condition on the sheared velocity has been identified to avoid the screening effect, that would prevent the RMP penetration, analytically and in numerical simulations. This works has been repeated in a turbulent plasma in presence or not of transport barrier (sheared velocity). The turbulent plasma generate an effective RMP amplification, while the transport barrier is affected by locked convective cells due to the RMP
Tounsi, Rami. "Comportement des structures en nids d'abeilles sous sollicitations dynamiques mixtes compression/cisaillement et effet de l'orientation des cellules." Phd thesis, Université de Valenciennes et du Hainaut-Cambresis, 2014. http://tel.archives-ouvertes.fr/tel-01002421.
Dietl, Thomas. "Modélisations numériques macroscopiques et microscopiques du comportement d'un matériau biphasique : applications à l'optimisation du cycle de fabrication des structures en béton de résine." Université Joseph Fourier (Grenoble), 1996. http://www.theses.fr/1996GRE10162.
Vilfayeau, Jérôme. "Modélisation numérique du procédé de tissage des renforts fibreux pour matériaux composites." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0026/document.
The aeronautical industry faces new challenges regarding the reduction of fossil fuel consumption. One way to address this issue is to use lighter composite materials. The ability to predict the geometry and the mechanical properties of the unit cell is necessary in order to develop 3D reinforcements in composite materials for these aeronautical applications. There is a difficulty to get realistic geometries for these unit cells due to the complexity of their architecture. Currently, existing tools which model 3D fabrics at a meso scale don't take into account manufacturing process influence on the shape modification of the textile structure. There is already some numerical tools that can model the braiding or knitting process, but none have been developed for weaving so far. Consequently, this study deals with the numerical simulation of the weaving process to obtain a deformed dry fabric structure. During the weaving process of E-glass fabrics, achieved in our laboratory, it has been observed that large deformations led to the modification of transverse section of meshes, or local density changes, that can modify the fabrics mechanical resistance. For this reason, a numerical tool of the weaving process, based on finite element modelling, has been developped to predict these major deformations and their influences on the final textile structure. The correlation between numerical results and fabrics produced with glass fibres has been achieved for plain weave and 2-2 twill
Doublet, Marie-Liesse. "Grandeurs Locales et Liaisons Chimiques :Des Outils d'Analyses pour l'Etude des Propriétés Macroscopiques des Solides Périodiques." Habilitation à diriger des recherches, Université Montpellier II - Sciences et Techniques du Languedoc, 2006. http://tel.archives-ouvertes.fr/tel-00185445.
Qu'il s'agisse des propriétés physiques comme le transport électronique et le magnétisme, ou des propriétés chimiques comme la réactivité chimique et l'oxydo-réduction, une approche locale visant à modéliser les interactions microscopiques au sein des différents systèmes doit permettre, dans le principe, de reproduire convenablement leurs propriétés macroscopiques (de basse énergie). Pour être efficace, cette approche nécessite une définition correcte de l'entité électronique active mais aussi des grandeurs physiques locales qui la caractérisent, incluant les effets de l'environnement. Établir une corrélation directe entre la nature de la liaison chimique (microscopique) et les propriétés physico-chimiques (macroscopiques) des matériaux est donc l'objectif dans lequel j'ai inscrit mes travaux de recherches depuis ma soutenance de Thèse en septembre 1994 et mon stage postdoctoral à l'Université libre d'Amsterdam. Mon travail explore à la fois des aspects méthodologiques et des applications, et vise à une meilleure description et une meilleure compréhension des phénomènes électroniques gouvernant l'arrangement structural des matériaux et les propriétés physico-chimiques qui en découlent. Une grande variété de propriétés a donc été abordée (transport, magnétisme, réactivité chimique et réactions électrochimiques), avec laquelle une grande variété de systèmes cristallins (moléculaires, covalents, organiques, inorganiques). A l'interface entre la physique et la chimie, ces études ont nécessité l'utilisation de formalismes théoriques différents mais également un investissement important dans le monde expérimental pour une bonne lecture des caractérisations physico-chimiques et des objectifs industriels.
Benezech, Jean. "Modélisation aux échelles méso- et macroscopique du comportement mécanique de zones singulières de pièces de structure en CMC." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0309.
Woven ceramic matrix composites (CMC) exhibit an intricate multi-scale architecture. To be used as components of aircraft engines, the weaving of such parts could also incorporate specific features compared to « classical » woven CMC as they need to comply with complex geometries. My work focused on a stiffener-like fully woven junction that is made of a complex 3D woven fabric, and whose characteristic size lies at the frontier between the mesoscopic and the macroscopic scales, i.e. where scale separation hypothesis is not applicable.I have first developed an experimental device to perform shear/bending tests on the woven junction. These tests not only allowed to gain significant knowledge about the mechanical behavior of such part, but also to highlight the interplay between the load, material architecture and damage mechanisms that is particularly significant in the case of the woven junction. Therefore, numerical prediction of the mechanical behavior of the woven junction necessitates a sound knowledge of its inner structure.With this aim, I have developed an original segmentation method to build realistic numerical models of textile composites, using X-ray micro-computed tomography and a prior geometric model. The procedure includes a global-local heuristic to iteratively improve the resemblance of the initial model. This approach allowed to build “digital twins” of the woven junction. A conformal tetrahedral image-based mesh could then be obtained as the resulting models are free of interpenetration. Mesoscale FE simulations, including non-linear behavior laws of the yarns and matrix, allowed to predict the maximal load leading to the first damage events, and to reproduce accurately the damage localization and its interaction with the architecture.However, with such level of details incorporated in the model, the simulations necessitate significant computational resources. An approximate macro-scale description may be sufficient to evaluate the elastic properties, or even to simulate damage initiation. Therefore, we have proposed a meso-informed macroscopic modelling framework where the behaviour of the macro-elements is derived from the knowledge of the local direction and volume fraction of constituents, thanks to the digital twin. The effective behaviour of the macro-elements is obtained through an equivalent lamina. This method drastically reduces the size of the model while preserving an approximate description of the underlying local anisotropy and heterogeneities. With respect to the damage initiation, the meso-informed macroscopic model accurately reproduced the results obtained using the reference mesoscale model, as long as the filtering size remains comparable to the yarn size. This allowed to propose an optimal modelling framework with an adequate level of description of meso-details and acceptable computational requirements.Finally, I have used these models to thoroughly compare the numerical simulations with the experimental results: variabilities of experimental boundary conditions have been analyzed, as well as the influence of specific heterogeneities related to the fabrication process. We have also used this framework to explore different weaving patterns in order to obtain an optimal design of the woven junction
Salamone, Salvatore. "Propriétés physiques des empilements de fibres macroscopiques : une approche expérimentale, théorique et numérique." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAE007/document.
The purpose of this work is to understand how intrinsic shape of individual fibers controls the collective behavior of fiber stacks, in particular the mechanical (elasticity) and electrical properties. We consider long fibers, aligned towards one preferential direction with a significant disorder shape. Our study is experimental and numerical. We propose a two dimensions self consistent mean field model which describes the collective elasticity from the individual properties of fibers : the disorder distribution and the bending modulus. We obtain an equation of state which describes with a good agreement the stacks elasticity, without any fit parameters, however up to a multiplicative constant. We obtain similar results between experimental and numerical studies
Dumazer, Guillaume. "Dynamique microscopique et propriétés macroscopiques de systèmes réactifs structurés : fronts d'onde chimiques exothermiques et prise du plâtre." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2010. http://tel.archives-ouvertes.fr/tel-00628301.
Schulmann, Nava. "Du polymère à la fibre : Conformations et élasticité de chaines à deux dimensions." Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAE014/document.
This PhD thesis is devoted to a theoretical study of polymer and ’polymer like’ systems in strictly two dimensions. Polymer systems in reduced dimensions are of high experimental and technological interest and present theoretical challenges due to their strong non-mean-field-like behavior manifested by various non-trivial universal power law exponents. We focus on the strictly 2D limit where chain crossing is forbidden and study as function of density and of chain rigidity conformational and elastic properties of three system classes: flexible and semiflexible polymers at finite temperature and macroscopic athermal polymers (fibers) with imposed quenched curvature. For flexible polymers it is shown that although dense self-avoiding polymers are segregated with Flory exponent ν = 1/2 , they do not behave as Gaussian chains. In particular a non-zero contact exponent θ2 = 3/4 implies a fractal perimeter dimension of dp = 5/4. As a consequence and in agreement with the generalized Porod law, the intramolecular structure factor F(q) reveals a non-Gaussian behavior and the demixing temperature of 2D polymer blends is expected to be reduced. We also investigate the effects of chain rigidity on 2D polymer systems and found that universal behavior is not changed when the persistence length is not too large compared to the semidilute blob size. The nature of the nematic phase transition at higher rigidities, which is in the 2D case the subject of a long standing debate, is also briefly explored. Preliminary results seem to indicate a first order transition. Finally, motivated by recent theoretical work on elastic moduli of fiber bundles, we study the effects of spontaneous curvature at zero temperature. We show that by playing on the disorder of the Fourier mode amplitudes of the ground state, it is possible to tune the compression modulus, in qualitative agreement with theory