No description available.

In terms of master’s thesis HAM-Tools library designed for MATLAB/Simulink was modified for the use in simulations of houses in the Czech Republic. Modified library and its parts were described in detail and tested by the simulation of the one-zone and two-zones models of the house. The simulations of models with same parameters were also realized in program TRNSYS. The corresponding results achieved in mentioned simulation tools were compared to each other. The one-zone model created by using HAM-Tools library is tested by the simulation of ventilating, heating, cooling, and sources of moisture. A demonstration of the practical use of the simulation is carried out in the thesis, namely by examining the influence of the insulation thickness on the thermal performance of the house (resp. its heat loss) on real atmospheric conditions. Among others, available resources of meteorological data are mentioned and compared to each other. The function for processing of the meteorological data to a file compatible with the HAM-Tools library was created. It was also created a material data file containing commonly used materials of building structures in the Czech Republic and their parameters.

Föreliggande studie är en kvalitativ intervjustudie som syftar till att undersöka erfarenheter av och uppfattningar om matematiklärande hos gymnasie- och vuxenstuderande i matematiksvårigheter för att därigenom öka kunskapen om denna elevgrupp och bättre kunna möta skilda undervisningsbehov. Frågeställningarna som ämnas besvaras är hur gymnasie- och vuxenstuderande som befinner sig i matematiksvårigheter beskriver sina möjligheter till lärande och utveckling i matematik och på vilket sätt dessa uppfattningar och erfarenheter kan relateras till begreppet matematisk resiliens. Matematisk resiliens härstammar ifrån psykologisk resiliens och handlar bland annat om att hantera och övervinna motgångar knutna till matematiklärande. Tidigare forskning kring matematisk resiliens är framförallt gjord i USA och Storbritannien och fenomenet är ännu inte studerat i någon högre utsträckning i svensk kontext. Intervjumaterialet har analyserats tematiskt med en hermeneutisk ansats. Studiens resultat presenteras i teman som beskriver möjlighet till lärande och utveckling i matematik kopplat till synen på förmåga, synen på arbete och ansträngning, synen på matematikens relevans och värde samt synen på hur känslor påverkar matematiklärandet. Resultatet diskuteras i relation till matematisk resiliens och vi konstaterar att arbetet med att öka elevers matematiska resiliens kan vara ett sätt för lärare och speciallärare i matematik att öka måluppfyllelse och att uppmärksamma de affektiva aspekterna av matematiklärande. Detta kan exempelvis ske genom användningen av the growth zone model och explicit undervisning kring olika studiestrategier samt att teorier om mindset särskilt beaktas vid utformandet av undervisningen. Sammanfattningsvis visar vår analys av resultatet att det är viktigt att ta i beaktande äldre elevers erfarenhetsmässiga bagage av återkommande misslyckanden och komplexa relation till matematiklärande.

Les propriétés du béton constituant les enceintes de confinement des centrales électronucléaires évoluent sous les effets de mécanismes de vieillissement résultant notamment de transferts couplés de chaleur et de masse au sein du matériau. Ces phénomènes peuvent être modélisés par des équations de transports moyennées : lois de Fick pour le transport d’espèces en solution et lois de Fourier pour la description de la diffusion thermique. Dans cette étude, les développements concernent la diffusion de la thermique dans un milieu hétérogène fissuré représentant un matériau cimentaire dégradé chimiquement. Le problème thermo-mécanique est traité à l'aide d'une approche multi-corps reliés par des lois d’interactions enrichies (zones cohésives). La diffusion thermique est écrite dans le formalisme cohésif-volumique en prenant en compte le couplage entre un état d'endommagement local de la zone cohésive et une conductivité homogénéisée. Afin d'optimiser les coûts de calculs, une étude est menée sur la dimension d'un volume élémentaire représentatif (VER). Pour cela, la méthode d'eigenerosion est étendue à la fissuration de milieux hétérogènes puis appliquée aux milieux cimentaires. La propagation de fissures sous chargement thermique est ensuite analysée dans des VERs de béton dégradés représentatifs des enceintes de confinement des centrales nucléaires après plusieurs années. Le vieillissement est modélisé par un taux de pré-dégradation initial entre le mortier et les granulats. Le développement de multi-fissures est relié au taux de pré-dégradation et la formation "d'écrans" à la diffusion de la thermique est mise en avant. / During their confinement in a nuclear power plant, the mechanical properties of the constitutive materials of concrete change as a result of ageing. This is due to the transportation of chemical species at the microscopic level of the media. Firstly, this can be modelled with average equations. The Fick laws represent the evolution of chemical diffusion and the Fourier laws, the transportation of heat at a mesoscopic level. In this research, we will consider thermal evolution on a fractured media.This thermomechanical problem is solved with a staggered method. The mechanical contribution used an approach based on multi-bodies system linked with cohesive zone models. The thermal problem is based on the approximation of the heat transfer equation at the cohesive interface. This approach has been implemented and validated. The description of the heat trough the interface is composed with the definition of an homogenised conductivity and the local damage parameter. In order to optimize the computational cost with a good agreement of the crack propagation, a criterion is proposed for sizing a representative elementary volume (REV). The eigenerosion method is used, validated and extended to heterogeneous media. Two studies are carried out on the morphological properties on a cementious media. As a result of those studies, a minimal size for a REV is defined.Crack spread under thermal loads are investigated on a media representing the concrete of the containment of a nuclear power station. The ageing effect are taken into account as an initial damage between the mortar and the aggregates. These parameters are expressed in terms of rate of initial damage. A study is proposed for different values of this rate. As assumed, the development of multi-cracks is linked with the rate of initial damage and the creation of thermal border is proposed.

<div>A combined experimental and computational study has been performed in order to understand the effect of interface chemical composition on the shock induced mechanical behavior of an energetic material (EM) system consisting of Hydroxyl-Terminated Polybutadiene (HTPB) binder and an oxidizer, Ammonium Perchlorate (AP), particle embedded in the binder. The current study focuses on the effect of interface chemical composition between the HTPB binder material and the AP particles on the high strain rate mechanical behavior. The HTPB-AP interface chemical composition was changed by adding cyanoethylated polyamine (HX-878 or Tepanol) as a binding agent. A power law viscoplastic constitutive model was fitted to nanoscale impact based experimental stress-strain-strain rate data in order to obtain the constitutive behavior of the HTPBAP interfaces, AP particle, and HTPB binder matrix. An in-situ mechanical Raman spectroscopy framework was used to analyze the effect of binding agent on cohesive separation properties of the HTPB-AP interfaces, AP particle, and HTPB binder matrix. In addition, a combined mechanical Raman spectroscopy and laser impact set up was used to study the effect of strain rate, as well as the interface chemical composition on the interface shock viscosity. Finally, high velocity strain rate impact simulations were performed using an explicit cohesive finite element method framework to predict the effect of strain rate, interface strength, interface friction, and interface shock viscosity on possible strain rate dependent temperature rises at high strain rates approaching shock velocities. </div><div><br></div><div>A modified stress equation was used in the cohesive finite element framework in order to include the effect of shock viscosity on the shock wave rise time and shock pressure during impact loading with strain rates corresponding to shock impact velocities. It is shown that increasing the interface shock viscosity, which can be altered by changing the interface chemical composition, increases the shock wave rise time at the analyzed interfaces. It is shown that the interface shock viscosity also plays an important role in determining the temperature increase within the microstructure. Interface shock viscosity leads to a decrease in the overall density of the possible hot-spots which is caused by the increase in dissipation at the shock front. This increase in shock dissipation is accompanied by a decrease in the both the maximum temperature, as well as the plastic dissipation energy, within the microstructure during shock loading.</div>

A ship to which vehicles and other loads can be rolled on and off is usually named ro-ro ship. A ro-ro ship consists of large corridor shaped space, normally extending to a considerable length or the entire length of the ship, which is usually loaded with various vehicles or stowage units. A ro-ro space can either be designed as an open space, closed space or a weather deck. There have been several fire incidents in ro-ro ship spaces and these fires occur with a relatively high frequency. A fire on a ro-ro ship is a very complex phenomenon. The fire development is hard to predict, and the fire tend to grow very quickly. One crucial parameter for the development of these fires is the ventilation, and the ventilation conditions may be totally different depending on the design of the ro-ro space.   This study was conducted in co-operation with RISE, the department of Fire Research, and the research project RO5. RO5 aims to clarify how the ventilation in ro-ro spaces affects the development of a fire and to possibly establish conceptual solutions for fire protection measures for ro-ro spaces with different ventilation conditions. The aim of this study is to explore tendencies of how both natural and mechanical ventilation affects the fire development within a ro-ro space. The intention is to provide basic knowledge regarding this subject, so that further simulations and tests could be optimized. The long-term goal of this study is to reduce the consequences, the severity and the number of fires within ro-ro spaces. The first step in the project is to explore the usefulness of two-zone models and compare the applicability of such method to experimental data. This is crucial in order to assess the applicability of two-zone models, especially as the aim is to make a parametric study of the influence of ventilation of fire development inside ro-ro space. A literature study of previous incident investigations of fires in ro-ro spaces was performed to gain knowledge concerning possible fire scenarios, ship constructions, fire development, consequences etc. and to provide an insight into how the ventilation was used in the case of a fire. In 2002, the research project “Model Scale Fire Tests on a Vehicle Deck Aboard a Ship” was issued by SP Swedish National Testing and Research Institute (now RISE). The aim was to simulate possible fire scenarios on a vehicle deck and examine what parameters can affect the fire development. To study this, tests were performed in model scale 1:8. The model had the dimensions 11.425 m x 2.786 m x 0.625 m (length x width x height). It was concluded that the ventilation and air supply being crucial for the fire development in ro-ro space. Although fires in a closed ro-ro space can quickly become ventilation-controlled, the fire may initially grow to be very large. One part of this study was to simulate some of the tests in “Model Scale Fire Tests on a Vehicle Deck Aboard a Ship” in the same sized model (scale 1:8). This was done since no tests on a full-scale model could be found. The simulation programs used were CFAST and B-RISK. The results were used for comparison to see how the two-zone simulations cohere with the tests. This was considered necessary due to limitations of the simulation programs and to the simplifications of two-zone fire model. By the comparison it was possible to choose the most suitable simulation program of the two, to use for further simulations in the study. The most suitable program was CFAST. Another part of the study was to conduct a parameter study. Since the model used in the tests in 2002 corresponded to an eight times larger model, the model was upscaled using Froude scaling to the dimensions 91.4 m x 22.3 m x 5 m (length x width x height). This model (scale 1:1) was then used in the parameter study. In the model, steel was used as material of the walls, ceiling and floor in order to imitate a real ro-ro space. By the results of the parameter study using two-zone fire simulations in CFAST, it is concluded that increased natural ventilation results in larger fire development, as well as increased mechanical ventilation results in larger fire development. Due to the results, open ro-ro spaces are recommended to be avoided. The regulations and definitions addressing closed ro-ro spaces are suggested to be reviewed since a closed ro-ro space can have relatively large natural ventilation. If natural ventilation is nevertheless required, the simulations indicate that openings constructed as wide as possible and with as low sill- and soffit height as possible are preferable. Because of the large size of a ro-ro space, there is enough oxygen to sustain a large fire during a given period. The fire will produce inert gases in the burning process such as CO2. As the gases reaches down to the fire source, the fire will start to fade. The oxygen within the ro-ro space will get pushed away by the process. The phenomenon is called inerting/vitiation and may occur when there is a fire within a ro-ro space. Previous investigations show that, the mechanical ventilation has been used to extract smoke in order to improve visibility and locate the fire. This measure may however be risky since mechanical ventilation may increase the fire development. Also, the mechanical ventilation may not be designed to be used for this purpose. In order to locate the fire efficiently for final extinguishment new improved and safer tactical methods is suggested to be evaluated. / Ett ro-ro fartyg är ett fartyg där fordon och annan last kan rullas på och av. Ombord på ett ro-ro fartyg finns det rorolastutrymmen. Ett rorolastutrymme är ett stort, korridorformat utrymme som vanligtvis är fyllt med fordon eller andra typer av last. Ett rorolastutrymme kan designas som ett öppet rorolastutrymme, ett slutet rorolastutrymme eller ett väderdäck. Det har skett flera brandincidenter på ro-ro fartyg och i rorolastutrymmen, samt har bränderna inträffat med en relativt hög frekvens. En brand på ett ro-ro fartyg är ett väldigt komplext fenomen. Brandutvecklingen är svår att förutse, och branden tenderar att växa väldigt fort. En viktig parameter för brandens utveckling är ventilationen. I ett rorolastutrymme kan ventilationsförhållandena vara väldigt olika beroende på hur utrymmet är utformat. Denna studie genomfördes tillsammans med RISE och forskningsprojektet RO5. RO5 syftar till att klargöra hur ventilationen i rorolastutrymmen påverkar brandutvecklingen, samt om möjligt, etablera konceptuella brandskyddsåtgärder för rorolastutrymmen med olika ventilationsförhållanden. Målet med denna studien är att studera tendenser av hur både naturlig och mekanisk ventilation påverkar brandutvecklingen i ett rorolastutrymme. Avsikten med denna studien är att få grundläggande kunskap inom ämnet, för att ytterligare simuleringar och kommande tester ska kunna optimeras i forskningsprojektet RO5. Det långsiktiga målet med studien är att minska konsekvenserna, brandstorleken, samt antalet bränder i rorolastutrymme. Metoden som användes i studien var tvåzonssimuleringar. För att få kunskap om möjliga brandscenarion, fartygskonstruktion, brandutveckling, konsekvenser etc. studerades tidigare olycksutredningar av bränder i rorolastutrymmen. Litteraturstudien gav också en inblick i hur ventilationen används vid händelse av brand i rorolastutrymmen. År 2002 utfördes “Model Scale Fire Tests on a Vehicle Deck Aboard a Ship” av SP, Sveriges Tekniska Forskningsinstitut (nuvarande RISE). Målet var att testa möjliga brandscenarion i ett rorolastutrymme och undersöka vilka parametrar som kan påverka brandens utveckling. Detta studerades genom att utföra tester i en nerskalad modell (skala 1:8). Modellen hade dimensionerna 11,425 m x 2,786 m x 0,625 m (längd x bredd x höjd). En slutsats var att ventilationen och syretillförseln var avgörande för brandens utveckling i ett rorolastutrymme. Även om branden i ett slutet rorolastutrymme snabbt kan bli ventilationskontrollerad, kan branden initialt bli väldigt stor. En del av studien var att simulera några av testerna som genomfördes i “Model Scale Fire Tests on a Vehicle Deck Aboard a Ship” i en modell av samma storlek (skala 1:8). Detta gjordes eftersom inga fullskaliga tester kunde hittas. De simuleringsprogram som användes var CFAST och B-RISK. Resultaten användes för att se hur simuleringarna stämde överens med verkliga tester. Detta bedömdes nödvändigt på grund av simuleringsprogrammens begränsningar och förenklingarna i tvåzonsmodellen. Genom jämförelsen kunde det mest lämpliga programmet av de två väljas ut för att använda i studiens fortsatta simuleringar. CFAST var det mest lämpliga programmet. En annan del av studien var att genomföra en parameterstudie. Eftersom modellen som användes i testerna 2002 motsvarar en åtta gånger så stor modell, skalades modellen upp med Froudes skalningslagar till dimensionerna 91,4 m x 22,3 m x 5 m (längd x bredd x höjd). Denna modellen (skala 1:1) användes därefter i en parameterstudie. För att modellen skulle efterlikna ett rorolastutrymme användes stål som väggar, tak och golv i modellen. Med resultaten från parameterstudien som utfördes i tvåzonssimuleringsprogrammet CFAST, kan slutsatsen dras att ökad naturlig ventilation resulterar i en större brandutveckling, samt att ökad mekanisk ventilation resulterar i en större brandutveckling. Baserat på resultaten rekommenderas det att öppna rorolastutrymmen bör undvikas. Definitionen för ett slutet rorolastutrymme föreslås att ses över eftersom ett slutet rorolastutrymme kan ha relativt mycket naturlig ventilation. Om naturlig ventilation dock krävs, indikerar simuleringarna på att öppningar konstruerade så breda som möjligt och med så låg sill- och bröstningshöjd som möjligt är att föredra. På grund av att rorolastutrymmen ofta är väldigt stora finns det tillräckligt med syre för att underhålla en stor brand under en viss tid. Branden kommer i förbränningsprocessen att producera inerta gaser som CO2 och när gaserna når ned till brandkällan kommer branden att börja avta. Syret i rorolastutrymmet kommer att tryckas bort av processen. Fenomenet kallas inertering/vitiation och kan förekomma vid en brand i ett rorolastutrymme. Tidigare utredningar visar på att mekanisk ventilation har använts för att ventilera ut rökgaser för att öka sikten och därmed kunna lokalisera branden. Denna åtgärd kan dock vara riskfull då mekanisk ventilation kan öka brandförloppet. Den mekaniska ventilationen är förmodligen inte heller designad för detta ändamål. För att kunna lokalisera en brand effektivt så att släckning kan genomföras, föreslås att nya, förbättrade och säkrare taktiker utvärderas.

Despite the phenomena of fracture and fatigue having been the focus of academic research for more than 150 years, it remains in effect an empirical science lacking a complete and comprehensive set of predictive solutions. In this regard, the focus of the research in this thesis is on the development of new cohesive-zone models for fracture and fatigue that are afforded an ability to capture strain-rate effects. For the case of monotonic fracture in ductile material, different combinations of material response are examined with rate effects appearing either in the bulk material or localised to the cohesive-zone or in both. The development of a new rate-dependent CZM required first an analysis of two existing methods for incorporating rate dependency, i.e.either via a temporal critical stress or a temporal critical separation. The analysis revealed unrealistic crack behaviour at high loading rates. The new rate-dependent cohesive model introduced in the thesis couples the temporal responses of critical stress and critical separation and is shown to provide a stable and realistic solution to dynamic fracture. For the case of fatigue, a new frequency-dependent cohesive-zone model (FDCZM) has been developed for the simulation of both high and low-cycle fatigue-crack growth in elasto-plastic material. The developed model provides an alternative approach that delivers the accuracy of the loading-unloading hysteresis damage model along with the computational efficiency of the equally well-established envelope load-damage model by incorporating a fast-track feature. With the fast-track procedure, a particular damage state for one loading cycle is 'frozen in' over a predefined number of cycles. Stress and strain states are subsequently updated followed by an update on the damage state in the representative loading cycle which again is 'frozen in' and applied over the same number of cycles. The process is repeated up to failure. The technique is shown to be highly efficient in terms of time and cost and is particularly effective when a large number of frozen cycles can be applied without significant loss of accuracy. To demonstrate the practical worth of the approach, the effect that the frequency has on fatigue crack growth in austenitic stainless-steel 304 is analysed. It is found that the crack growth rate (da/dN) decreases with increasing frequency up to a frequency of 5 Hz after which it levels off. The behaviour, which can be linked to martensitic phase transformation, is shown to be accurately captured by the new FDCZM.

Over the last few decades, Shape Memory Alloys (SMAs) have been increasingly explored in order to take advantage of their unique properties (i.e., pseudoelasticity and shape memory effect), in various actuation, sensing and absorption applications. In order to achieve an effective design of SMA-based devices a thorough investigation of their behavior in the presence of cracks is needed. In particular, it is important to understand the effect of phase transformation on their fracture response. The aim of the present work is to study the effect of stress-induced as well as thermo-mechanically-induced phase transformation on several characteristics of the fracture response of SMAs. The SMA thermomechanical response is modeled through an existing constitutive phenomenological model, developed within the framework of continuum thermodynamics, which has been implemented in a finite element frame-work. The effect of stress-induced phase transformation on the mechanical fields in the vicinity of a stationary crack and on the toughness enhancement associated with crack advance in an SMA subjected to in-plane mode I loading conditions is examined. The small scale transformation assumption is employed in the analysis according to which the size of the region occupied by the transformed material forming close to the crack tip is small compared to any characteristic length of the problem (i.e. the size of the transformation zone is thirty times smaller than the size of the cracked ligament). Given this assumption, displacement boundary conditions, corresponding to the Irwin’s solution for linear elastic fracture mechanics, are applied on a circular region in the austenitic phase that encloses the stress-induced phase transformation zone. The quasi-static stable crack growth is studied by assuming that the crackpropagates at a certain critical level of the crack-tip energy release rate. The Virtual Crack Closure Technique (VCCT) is employed to calculate the energy release rate. Fracture toughness enhancement associated with transformation dissipation is observed and its sensitivity on the variation of key characteristic non-dimensional parameters related to the constitutive response is investigated. Moreover, the effect of the dissipation due plastic deformation on the fracture resistance is analyzed by using a Cohesive Zone Model (CZM). The effect of thermo-mechanically-induced transformation on the driving force for crack growth is analyzed in an infinite center-cracked SMA plate subjected to thermal actuation under isobaric mode I loading. The crack-tip energy release rate is identified as the driving force for crack growth and is measured over the entire thermal cycle by means of the VCCT. A substantial increase of the crack-tip energy release rate – an order of magnitude for some material systems – is observed during actuation as a result of phase transformation, i.e., martensitic transformation occurring during actuation causes anti-shielding that might cause the energy release rate to reach the critical value for crack growth. A strong dependence of the crack-tip energy release rate on the variation of the thermomechanical parameters characterizing the material response is examined. Therefore, it is implied that the actual shape of the strain- temperature curve is important for the quantitative determination of the change of the crack-tip energy release rate during actuation.

L’objectif de cette thèse est de modéliser en temps réel la propagation d’un incendie dans des ensembles comportant un grand nombre de locaux. Un modèle semi-physique de réseau polydisperse amorphe prenant en compte les connexions à courte et longue distances entre sites, est proposé. Les phénomènes physiques liés au développement du feu dans un local et à sa transmission entre locaux par les parois sont simulés par des lois normales de probabilité. Les durées moyennes de transmission par les parois sont déterminées à l’aide d’un modèle à zones prenant en compte les spécificités du local en feu. Des expérimentations spécifiques dans un caisson en acier, représentatif d’un local de la Marine Nationale, ont permis de valider le modèle à zones. Un exemple détaillé du calcul par le modèle de réseau de la propagation d’un feu dans une maquette de navire à échelle un est ensuite décrit et analysé pour différents scénarios. Une analyse de sensibilité utilisant un plan factoriel complet à deux niveaux permet de hiérarchiser les paramètres du modèle et d’étudier la sensibilité de la solution aux variations de ces paramètres. Une étude statistique est conduite afin d’établir une cartographie du risque incendie à bord du navire. La transmission du feu par les gaines de ventilation est simulée par une loi normale de probabilité où la durée moyenne de transmission est déterminée à l’aide d’un code à champ unidimensionnel. Après avoir validé ce code sur des mesures obtenues par DGA dans une conduite cylindrique différentiellement chauffée, l’influence de ce mode de transmission sur la propagation du feu dans le navire est analysée. / This thesis work is devoted to the development of a semi-physical network model to predict real-time fire spread in polydisperse amorphous massively multi-compartmented spaces. This model takes into account short-range and long-range connections between adjacent and remote network sites. The physical phenomena of fire ignition and flashover, and of fire transmissions through the walls are simulated using time-dependent normal probability distributions. Mean durations of transmission though the walls are determined by a two-zone model which takes into account the fuel load, the room size and the thermal properties of walls. Specific experiments were conducted in a steel room, representative of a naval vessel compartment, in order to validate the zone model. Then a proof of concept is developed by applying the network model to different fire scenarios in a full-scale vessel mockup. A sensitivity analysis using a two-level full factorial design is performed to identify the most influential model parameters and to evaluate the sensitivity of the solution to variations of these parameters. A statistical study is conducted to produce fire risk maps. Finally, a special emphasis is put on the fire transmission by the ventilation ducts. This phenomenon is simulated using a time-dependent normal probability distribution where the mean duration is determined by means of a one-dimensional CFD model. This model is first validated using data obtained by DGA in a differentially heated duct and second, the influence of fire transmission through ventilation duct on its propagation throughout the vessel is investigated.

Les composites stratifiés de plis unidirectionnels en carbone/époxy sont fortement utilisés pour alléger les structures aéronautiques tout en conservant de bonnes propriétés structurales. Toutefois, les avantages de ce type de matériau ne sont pas encore pleinement exploités de par le manque de confiance accordée aux modèles de prévision de l’endommagement, dont notamment ceux concernant le délaminage. C’est pourquoi l’objectif de cette thèse était de développer une stratégie de modélisation du délaminage adaptée aux structures composites stratifiées. Cette stratégie s’est appuyée sur le développement d’un modèle de zone cohésive prenant en compte les ingrédients nécessaires à la bonne description de l’amorçage et de la propagation de la fissure : (i) un critère d’amorçage avec un renforcement en compression/cisaillement hors-plan, (ii) une loi de propagation décrivant l’évolution de la ténacité en fonction de la mixité de mode et (iii) la prise en compte du couplage inter/intralaminaire. Pour identifier ce nouveau modèle, une procédure d’identification efficace, s’appuyant sur un essai de traction sur plaque rainurée, a été mise en place. Cette procédure d’identification a permis de démontrer que la ténacité semble indépendante (i) de l’orientation des plis adjacents à l’interface et (ii) de l’empilement étudié. De même, pour décrire l’évolution de la ténacité, une nouvelle loi de propagation adaptée au matériau carbone/époxy a été proposée. Pour finir, la stratégie de modélisation, complétée par une stratégie de calcul, a été appliquée sur différents cas structuraux pour mettre en avant ses apports et ses premières limites. / The carbon/epoxy laminated composites of unidirectional plies are strongly used in order to reduce the weight of aeronautical structures while at the same time proposing good structural properties. However, the advantages of this kind of material are not fully exploited due to the lack of confidence in damage models, like ones concerning delamination. Then, the purpose of this work was the development of a strategy to model delamination in laminated composite structures. This strategy was based on the development of a cohesive zone model taking into account the ingredients necessary to the well description of the onset of delamination and the crack growth: (i) an onset criterion with an out-of-plan compression/shearing reinforcement, (ii) a propagation law describing the evolution of the fracture toughness as a function of mixed mode ratio and (iii) the inter/intralaminar coupling. To identify this new model, an efficient identification procedure, basing on a tensile test on notched specimen, has been proposed. This identification procedure has demonstrated that the fracture toughness seems to be independent of (i) the orientation of plies closed to the interface and (ii) the stacking sequence. Furthermore, to describe the evolution of the fracture toughness, a new propagation law adapted to carbon/epoxy material has been proposed. Finally, the strategy to model delamination, completed by a calculation strategy, has been applied on several structural cases to prove its contributions and its first limitations.