Ultrasonic welding (UW), as a solid-state joining process, uses an ultrasonic energy source (usually with a frequency of 20 kHz or above) to induce oscillating shears between the faying surfaces to produce metallurgical bonds between a wide range of metal sheets [1, 2], thin foils [3], semiconductors [4], plastics [5], glass [6], and ceramics [7]. In contrast to traditional fusion welding processes, ultrasonic welding has several inherent advantages [3,8] derived from its solid-state process characteristics, and has been in use as a versatile joining method in the electronics, automotive, and aerospace industries since the 1950s

Les systèmes de protection thermique ablatifs, couramment utilisés dans l'industrie de l'aérospatiale sont généralement des matériaux composites, dont la dégradation permet d'isoler thermiquement les éléments subissant des flux aérothermiques sévères. On recense dans la littérature de très nombreux systèmes, tant en terme de matrice que de type de renfort. Face à la diversité des matériaux existants et la multiplicité des sollicitations auxquelles ils peuvent être soumis, il est aujourd'hui nécessaire d'acquérir une meilleure connaissance de l'influence de la composition (matrice, renfort et porosité) de ces matériaux sur leur comportement thermique et leur tenue à l'ablation. La démarche scientifique des travaux s'articule autour d'un volet expérimental et du développement d'un modèle numérique. La caractérisation expérimentale a été construite en trois étapes, explorant chacune le comportement des matériaux à une échelle différente : le comportement thermo-chimique a été caractérisé par des essais d'ATG, de TMA et de DSC, le comportement thermique a été évalué grâce à un banc muni d'une torche oxygène acétylène. Enfin, la tenue des matériaux à un jet aérothermique sévère a été testée sur un banc d'essai équipé d'un minipropulseur. Ce dernier banc permet de tester des échantillons de plusieurs dizaines de centimètres de large et d'étudier l'impact couplé de la thermique et de l'aérodynamique. En parallèle, un modèle numérique simple simulant l'ablation a été développé et validé. L'ensemble de ces travaux ont notamment permis de mettre en évidence les liens existants entre les propriétés thermo-physiques et la tenue à l'ablation d'un matériau composite. Appuyée par des observations microscopiques des matériaux dégradés, l'étude combinée des résultats aux différentes échelles a permis de proposer des scénarii de dégradation pour chacun des matériaux. Les principaux paramètres pilotant l'avancée d'un front d'ablation ont été identifiés, l'impact primordial de la porosité a notamment été démontré. / Ablative thermal protection systems, commonly used in space industry, are usually made of composite materials. The degradation of these materials in surface allows to protect essential parts against severe aerothermal fluxes. In the literature, lots of different systems are described they are constituted of different type of matrix and reinforced by several kind of fibers. The diversity of the existing thermal protection systems raises the question of the influence of the composition of the materials on the thermal and ablative performances. The developed scientific approach is based on an experimental procedure coupled with the development of a numerical simulation. The material characterization is based on three experimental steps : the thermo-chemical behavior of the materials is investigated with TGA, TMA and DSC experiments, the thermal behavior under a severe flux is evaluated by an experimental bench equipped with an oxyacetylenic torch ; finally, the ablative behavior is characterized with a small jet-nozzle impacting the sample with a severe aerothermal flux. In parallel to the experimental characterization, a numerical simulation modeling of the ablative and thermal behavior of composite materials is developed. Links existing between the thermal behavior and the ablation resistance have been demonstrated. Degradation scenarios have been proposed thanks to the combined analysis of the experimental results at each stage of the characterization. Parameters controlling the ablation have been identified, the major impact of the porosity has been particularly demonstrated.

Laser cutting is a widely used technology for precision cutting of various materials, in-cluding mild structural steel. It involves the use of a high-powered laser beam to melt, burn, or vaporize the material, resulting in a clean and accurate cut. This doctoral thesis presents a comprehensive investigation of the laser cutting process for mild structural steels. To understand the thermal effects on the steel workpiece, an analytical model for the laser cutting heat source is proposed, which takes into account laser source geometry variation along the cut edge thickness. A modified heat source based on a Gaussian dis-tribution is used to model the heat flux as a combination of laser beam and heat produced by the reaction of oxygen with iron. The proposed model allows the laser cutting process to be simulated as a function of cutting speed, laser power, and shape of the heat flux. The FE method is employed to predict both temperature and stress fields in the cutting section considering the solid-state phase transformation during and after the laser cutting process. Optical microscopy, scanning electron microscopy and microhardness measure-ments are employed to observe morphological and metallurgical changes in the cutting sections, and the stress is detected using the X-ray diffraction methodology. The residual stress field surrounding the cutting edges is experimentally examined, and the results are compared to those anticipated by the developed model. An accurate temperature distri-bution field is obtained and validated by microstructural solid phases of the cut specimens. Consequently, residual stresses are also validated by comparing experimental measure-ments and outputs of the FE model. The study also investigates the optimization of laser cutting parameters for achieving, in agreement with the standard EN ISO 9013, quality cut surface requirements, such as roughness and perpendicularity. The trial-and-error method used in the past is incompat-ible with environment-friendly processes. Hence, to study the effects of cutting parameters on the target parameters and to collect data, an experimental campaign is carried out on a 12 mm thickness low carbon steel grade S235 cut by a 4kW fiber laser. A multi-objective optimization based on both a genetic algorithm and Kriging method is carried out to in-vestigate the correlations between input and target parameters as well as to find the op-timal laser cutting parameters to achieve the minimum roughness and perpendicularity. The applicability of the Kriging method to laser cutting processes is highlighted by the agreement between predicted cut quality and experimental results, provided by additional specimens cut with laser parameter sets obtained by a Pareto front. Overall, the investi-gated model offers important details on the physical procedures that occur during the laser cutting process and provides useful insights for selecting the optimal sets of laser cutting parameters for different applications.

Yes / We have performed shrinkage restraint force measurements on three shape memory polymers of polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) and a blend of the two at a range of temperatures. Observations are made of the change in stress during temperature rise, hold and cooling. All materials show an increase in stress during rise and hold, but on cooling the three materials behave differently; the PET shows a drop in stress, the PMMA a rise and the blend a much smaller rise. This behaviour correlates with the reversible thermal dimensional change at below the shrinkage threshold temperature; the expansion coefficients are negative for PET, positive for PMMA and positive at a lower order of magnitude for the blend. We model the behaviour by supposing that the shrinkage forces are created by prestressed strains effective at long range within a matrix of shorter chains effective at short range. The total stress is the sum of the shrinkage stress and the thermal stress in the matrix. The drops in stress on cooling are modelled using an elastic analysis based on measured elastic moduli and thermal expansion coefficients. For the blend, downward jumps in temperature produce small transient increases in the total stress, leaving it effectively unchanged. This phenomenon and the results of the elastic model for the stress drops imply that the shrinkage stress from the long-range chain network is largely unaffected by the temperature change, and so is not entropic.

<div>The objective of this dissertation is to develop new methods in the areas of multiscale topology optimization, thermomechanical topology optimization including heat convection, and thermal-fluid topology optimization. The dissertation mainly focuses on developing five innovative topology optimization algorithms with respect to structure and multistructure coupling fluid, thermal and mechanical analysis, in order to solve customary design requirements. Most of algorithms are coded as in-house code in MATLAB.</div><div><br></div><div><div>In Chapter One, a brief introduction of topology optimization, a brief literature review and the objective is presented. Five innovative algorithms are illustrated in Chapter Two</div><div>to Six. From Chapter Two to Four, the methods with respect to multiscale approach are presneted. and Chapter Five and Six aims to contribute further research associated with</div><div>topology optimization considering heat convection. In Chapter Two, a multiphse topology optimization of thermomechanical structures is presented, in which the optimized structure is composed of several phases of prescribed lattice unit cells. Chapter Three presents a</div><div>Multiscale, thermomechanical topology optimization of self-supporting cellular structures. Each lattice unit cell have a optimised porousity and diamond shape that benefit additive</div><div>manufacturing. In Chapter Four, the multiscale approach is extended to topology optimization involved with fluid mechanics problem to design optimized micropillar arrays in</div><div>microfludics devices. The optimised micropillars minimize the energy loss caused by local fluid drag force. In Chapter Five, a novel thermomechanical topology optimization is developed, in order to generate optimized multifunctional lattice heat transfer structure. The algorithm approximate convective heat transfer by design-dependent heat source and natural convection. In Chapter Six, an improved thermal-fluid topology optimization method is created to flexibly handle the changing of thermal-fluid parameters such as external heat source, Reynolds number, Prandtl number and thermal diffusivity. The results show the</div><div>changing of these parameters lead versatile optimized topologies. Finally, the summary and recommendations are presented in Chapter Seven.</div></div><div><br></div>

This study aims at the description, modelling and numerical prediction of ductile fracture in inelastic solids undergoing thermomechanical static or dynamic loading. Several research areas of contemporary interest in computer analysis of solids and structures are covered. The theoretical methodologies, computer implementations and practical applications will be treated. This thesis summarizes my recent research works since 1989 at the MSM Department of the University of Liège. However, it should also be useful to those who are interested in the most recent developments in finite element methods and in applying these techniques to the analysis of real industrial problems. Numerous references to original sources are included. For the convenience of the reader, each chapter of the thesis is designed to be self-contained, starts with a summary of the topic addressed, and finishes with an outline of the main results presented. Numerical examples are organized at the end of chapter 2 to 8 to assess the performance and applicability of the proposed mechanical and finite element models developed in each of them. Hereafter, a brief overview of the thesis is given. After a brief introduction in chapter 1, the numerical tools that are necessary to perform large strain thermomechanical static or dynamic analysis of solids are presented. In chapter 2, a general strategy for nonlinear dynamic finite element formulation is presented, including explicit and implicit time integration schemes. A special emphasis is placed on the application of high-speed metalforming and frictional contact-impact problems. Chapter 3 describes a strategy for solving problems involving transient thermal and thermomechanical analysis. A class of unified and mixed solid, thermal and coupled thermomechanical finite elements by assumed strain method is developed in chapter 4. Special care is taken to hourglass ans locking control. Once these developments are validated and their efficiency tested, it is then possible to tackle the problem of ductile fracture prediction and propagation. In chapter 5, a bibliographic research on the "local approach of ductile fracture" is presented. The implementation of six fracture criteria into various constitutive laws for predicting fracture initiation sites is also shown. A fully coupled elasto(-visco)-plastic damage model for isotropic material is developed in chapter 6. This model is based on irreversible thermodynamics theory and on the energy equivalence hypothesis. Chapter 7 presents the theoretical and experimental comparison for isotropic ductile material at fracture. Finally in chapter 8, the isotropic damage model of chapter 6 is extended to the case of anisotropic solids in which the damage growth itself is also anisotropic. The above developments have been implemented to an existing finite element code LAGAMINE developed since 1982 at the MSM Department of the University of Liège and are applied to many real engineering problems such as high speed rolling, magnetoforming, impact upsetting, dynamic forging, deep drawing of axisymmetric ans square cups, hot upsetting, warm folding of 3D sheet, non-isothermal hemispherical punch stretching, and other contact-impact examples.

Applications of chromium vary widely (refractories, chemicals and metallurgical); however, the greatest benefit of chromium is its ability to improve the corrosion resistance, strength and hardness of steel. South Africa possesses approximately 75% of the viable global chromite reserves and, as a result, dominates the ferrochrome market with production in excess of 5 million mega tonnes per year - making it an industry of extreme importance to the South African economy Submerged arc ferroalloy production furnaces mainly use Soderberg electrodes - self–baking continuous electrodes that are produced in situ during furnace operation. Electrode breakings may affect a furnace in a number of ways depending on the nature and location of the break. Low furnace power input, abnormal charging and tapping conditions, as well as loss of production are among the more common negative implications associated with electrode breaks. The successful operation of Soderberg electrodes is dependent on two main factors: high quality electrode paste and effective electrode management procedures. This study focused on electrode paste quality. The raw materials utilised in the production of Soderberg electrode paste consists of calcined anthracite mixed with a tar pitch binder. In this study the focus was on the development of an experimental procedure to measure the dimensional changes of electrode paste raw materials as a function of temperature by means of thermomechanical analysis (TMA). Three uncalcined anthracite (Zululand chips, Zululand duff, and Tendele duff) and two tar pitch samples (low and high softening point pitches, i.e. LSP and HSP) were obtained from a local paste producer. Electrode graphite samples were also obtained from a local pre–baked electrode supplier. The experimental procedure for both the anthracite and tar pitches consisted of two phases: sample preparation and TMA measurements. During the sample preparation procedure for the tar pitches, the two tar pitches were heat treated in order to prevent softening in the TMA (preventing possibly damage the instrument), where after pellets were pressed for TMA measurement. The anthracite samples were calcined at 1200, 1300 and 1400°C in the anthracite sample preparation phase. TMA sample pellets of calcined and uncalcined anthracite were pressed using only water as a binder. TMA was performed on pellets produced from the heat–treated tar pitch samples, uncalcined and calcined anthracite samples, as well as core drilled pellets of the pre–baked electrode graphite. The dimensional changes of these pellets were measured, as a function of temperature, through three consecutive heating (room temperature to 1300°C) and cooling (1300°C to approximately 100°C) cycles under a N2 atmosphere. A significant shrinkage (> 12%) for both the LSP and HSP tar pitches occurred during the first TMA heating cycle. During the second and third heating cycles of the LSP and HSP tar pitches, dimensional changes were approximately 2%. This indicates that substantial structural reordering of the carbonaceous binder takes place during the first heating cycle. TMA results obtained for all three the calcined anthracite samples investigated indicated thermal dimensional changes of less than 1%. The anthracite samples calcined at the highest experimental calcination temperature (1400°C) prior to TMA analysis had the smallest dimensional changes. This confirmed that higher calcination temperatures result in a higher level of structural ordering and dimensional stability. Considering the combined calcined anthracite and tar pitches TMA results, the importance of the initial baking of a Soderberg electrode at temperatures exceeding the baking isotherm temperature (475°C) becomes apparent - the dimensional behaviour of the tar pitch binder and the calcined anthracite differ dramatically, making the newly–formed electrode very susceptible to breakage. Once structural reordering of the pitch had taken place, thermal dimensional behaviours of the materials are much more similar, significantly reducing the risk of thermal shock–induced electrode breakages. In contrast to the relatively small dimensional changes measured for the calcined anthracite samples, the shrinkages measured for the uncalcined samples during the first TMA heating/cooling cycle were substantial (6–8%). This indicates the importance of the anthracite calcination process, before the electrode paste is formulated. Improperly calcined anthracite present in electrode paste would result in additional dimensional shrinkage that would have to be accommodated in the baking of a new electrode section. Considering the large shrinkage of the tar pitch that already takes place, it is unlikely that a strong enough electrode would be formed if this occurs. From the results, it also became apparent that the anthracite with the highest fixed carbon and lowest ash contents exhibited the smallest shrinkage during in situ TMA calcination. High fixed carbon, low ash type anthracites are therefore less prone to dimensional instabilities in Soderberg electrodes, as a result of poor calcination. The dimensional changes observed in the calcined anthracites were very similar to those observed for the electrode graphite samples. The expansions/shrinkages observed in the graphite samples were mostly less than 0.5%, whereas the expansions/shrinkages observed in the various calcined anthracites were approximately 0.6 to 0.9%. The difference in the magnitude of the dimensional behaviour between the calcined anthracites and the graphite can be attributed to the fact that the graphite had already undergone maximum structural ordering (having been pre–baked at 3000°C). / Thesis (M.Ing. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2012.

Applications of chromium vary widely (refractories, chemicals and metallurgical); however, the greatest benefit of chromium is its ability to improve the corrosion resistance, strength and hardness of steel. South Africa possesses approximately 75% of the viable global chromite reserves and, as a result, dominates the ferrochrome market with production in excess of 5 million mega tonnes per year - making it an industry of extreme importance to the South African economy Submerged arc ferroalloy production furnaces mainly use Soderberg electrodes - self–baking continuous electrodes that are produced in situ during furnace operation. Electrode breakings may affect a furnace in a number of ways depending on the nature and location of the break. Low furnace power input, abnormal charging and tapping conditions, as well as loss of production are among the more common negative implications associated with electrode breaks. The successful operation of Soderberg electrodes is dependent on two main factors: high quality electrode paste and effective electrode management procedures. This study focused on electrode paste quality. The raw materials utilised in the production of Soderberg electrode paste consists of calcined anthracite mixed with a tar pitch binder. In this study the focus was on the development of an experimental procedure to measure the dimensional changes of electrode paste raw materials as a function of temperature by means of thermomechanical analysis (TMA). Three uncalcined anthracite (Zululand chips, Zululand duff, and Tendele duff) and two tar pitch samples (low and high softening point pitches, i.e. LSP and HSP) were obtained from a local paste producer. Electrode graphite samples were also obtained from a local pre–baked electrode supplier. The experimental procedure for both the anthracite and tar pitches consisted of two phases: sample preparation and TMA measurements. During the sample preparation procedure for the tar pitches, the two tar pitches were heat treated in order to prevent softening in the TMA (preventing possibly damage the instrument), where after pellets were pressed for TMA measurement. The anthracite samples were calcined at 1200, 1300 and 1400°C in the anthracite sample preparation phase. TMA sample pellets of calcined and uncalcined anthracite were pressed using only water as a binder. TMA was performed on pellets produced from the heat–treated tar pitch samples, uncalcined and calcined anthracite samples, as well as core drilled pellets of the pre–baked electrode graphite. The dimensional changes of these pellets were measured, as a function of temperature, through three consecutive heating (room temperature to 1300°C) and cooling (1300°C to approximately 100°C) cycles under a N2 atmosphere. A significant shrinkage (> 12%) for both the LSP and HSP tar pitches occurred during the first TMA heating cycle. During the second and third heating cycles of the LSP and HSP tar pitches, dimensional changes were approximately 2%. This indicates that substantial structural reordering of the carbonaceous binder takes place during the first heating cycle. TMA results obtained for all three the calcined anthracite samples investigated indicated thermal dimensional changes of less than 1%. The anthracite samples calcined at the highest experimental calcination temperature (1400°C) prior to TMA analysis had the smallest dimensional changes. This confirmed that higher calcination temperatures result in a higher level of structural ordering and dimensional stability. Considering the combined calcined anthracite and tar pitches TMA results, the importance of the initial baking of a Soderberg electrode at temperatures exceeding the baking isotherm temperature (475°C) becomes apparent - the dimensional behaviour of the tar pitch binder and the calcined anthracite differ dramatically, making the newly–formed electrode very susceptible to breakage. Once structural reordering of the pitch had taken place, thermal dimensional behaviours of the materials are much more similar, significantly reducing the risk of thermal shock–induced electrode breakages. In contrast to the relatively small dimensional changes measured for the calcined anthracite samples, the shrinkages measured for the uncalcined samples during the first TMA heating/cooling cycle were substantial (6–8%). This indicates the importance of the anthracite calcination process, before the electrode paste is formulated. Improperly calcined anthracite present in electrode paste would result in additional dimensional shrinkage that would have to be accommodated in the baking of a new electrode section. Considering the large shrinkage of the tar pitch that already takes place, it is unlikely that a strong enough electrode would be formed if this occurs. From the results, it also became apparent that the anthracite with the highest fixed carbon and lowest ash contents exhibited the smallest shrinkage during in situ TMA calcination. High fixed carbon, low ash type anthracites are therefore less prone to dimensional instabilities in Soderberg electrodes, as a result of poor calcination. The dimensional changes observed in the calcined anthracites were very similar to those observed for the electrode graphite samples. The expansions/shrinkages observed in the graphite samples were mostly less than 0.5%, whereas the expansions/shrinkages observed in the various calcined anthracites were approximately 0.6 to 0.9%. The difference in the magnitude of the dimensional behaviour between the calcined anthracites and the graphite can be attributed to the fact that the graphite had already undergone maximum structural ordering (having been pre–baked at 3000°C). / Thesis (M.Ing. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2012.

[pt] O entendimento dos processos que levam à instabilidade de taludes rochosos é de grande importância em análises de risco. Normalmente, desplacamentos e quedas de blocos de rocha ocorrem em épocas sem chuva, levando a crer que existem outros fatores deflagradores que devem ser analisados. Estudos relativamente recentes tem levantado a importância das tensões térmicas na propagação de fissuras e noacúmulo de tensões de tração. De forma a avaliar o impacto da ciclagem térmica sobre a rocha, foram realizadas análises termomecânicas utilizando o software de elementos finitos Abaqus 6.14. Nas simulações efetuadas foram utilizadas geometrias simplificadas, representativas de placas rochosas reais de áreas costeiras do Brasil. O maciço rochoso foi considerado isotrópico e homogêneo e os parâmetros térmicos utilizados (condutividade, calor específico e coeficiente de expansão térmica) foram adotados de acordo com valores obtidos na literatura para rochas de origem e constituição similar às rochas presentes na costa da região sudeste do Brasil (Gnaisses e Granitos). As condições de contorno de temperatura foram obtidas através de campanhas experimentais extraídas de estudo anterior. Admitiu-se ainda, apenas a ocorrência do modo I de propagação de fraturas, sendo a análise da propagação restrita a comparação entre K1c e os valores K1 desenvolvidos. Os resultados das simulações numéricas mostraram que a ocorrência de baixas temperaturas e de altos gradientes térmicos entre as faces externa e interna da placa ocasionam os maiores valores de K1, cuja magnitude é comparável aos valores de K1c típicos para rochas encontradas na região sudeste do Brasil. / [en] The understanding of the processes that lead to instability of rock slopes is of great importance in risk analysis. Normally, detachments and rockfalls occur in times without rain, leading to belief that there are other triggering factors that need to be evaluated. Relatively recent studies have raised the importance of thermal stresses in the propagation of cracks and in the accumulation of tensile stresses. In order to evaluate the impact of thermal cycling on the rock, thermomechanical analyzes were performed using Abaqus 6.14 finite element software. In the simulations, simplified geometries were used, representative of real rock plates of coastal areas of Brazil. The rock mass was considered isotropic and homogeneous and the thermal parameters (conductivity, specific heat and coefficient of thermal expansion) were adopted according to values obtained in the literature for rocks of origin and constitution similar to the rocks present in the coast of the southeastern region of Brazil (Gneisses and Granites). The temperature contour conditions were obtained through experimental campaigns extracted from a previous study. Only the occurrence of mode I of fracture propagation was allowed, with propagation analysis being restricted to the comparison between K1c and the K1 values developed. The results of the numerical simulations showed that the occurrence of low temperatures and high thermal gradients between the outer and inner faces of the plate cause the highest values of K1, whose magnitude is comparable to the values of K1c typical for rocks found in the southeastern region of Brazil.

Pour être commercialisés et installés à bord des navires, les panneaux structuraux tels que les cloisons et les pontsdoivent passer avec succès un essai normalisé de résistance au feu de type ISO 834. De tels essais sont longs et coûteux,les constructeurs de panneaux souhaitent par conséquent maximiser les chances de succès lors du passage de leur produitau test en particulier pour les designs alternatifs que constituent les sandwichs composite.La simulation par éléments finis est un outil pour modéliser le comportement thermomécanique de telles structures.Les codes industriels comme SAMCEF qui a été utilisé dans ce travail sont capables de réaliser des analyses thermiquesavec dégradation et des analyses mécaniques mettant en jeu la gestion du contact, la dégradation des propriétésmécaniques et la perte des structures par ruine.L’enjeu de cette étude est d’abord identifier les spécificités de telles structures particulières par leur taille, leurconception, de déterminer quelles sont les données thermiques et mécaniques nécessaires pour alimenter le modèlenumérique et le cas échéant de les construire à partir des résultats de la réaction au feu des matériaux. Des modèlesnumériques que l’on souhaite robustes et utilisables dans un contexte industriel, sont développés pour déterminer lecomportement thermomécanique de tels panneaux. Ils prennent en compte l’évolution des propriétés thermiques etmécaniques des matériaux en cours de dégradation. Ces modèles doivent permettre par la suite l’estimation desperformances de nouveaux designs lors d’un essai de certification ISO 834. / Structural panels used in naval industry such as bulkheads and decks must succeed in standard certification testssuch as ISO 834 to be commercialized and settled on board. As these tests are long and expensive, panel manufacturerswish to maximize chances of success for their panels when submitted to certification tests especially when it comes toalternative designs such as composite sandwich panels.Finite elements analyses are used to model thermo-mechanical behavior. Industrial software such as SAMCEF,which was used to conduct this work, are able to solve thermal analyses with degradation and mechanical analyses involvingcontact conditions, degradation of mechanical properties and loss of structures due to failure.The objective in this study is to first identify characteristics of these structures. They are special due to their size andtheir manufacturing. This study aims also to determine thermal and mechanical data required for numerical modeling.When necessary some data can be computed from results coming from the results of the materials’ reaction to fire.Numerical models are developed to determine thermo-mechanical behavior and are designed to be robust and used inindustrial context. They include the evolution of thermal and mechanical properties during the degradation process. Thesemodels must enable to estimate the performances of innovative designs during an ISO 834 certification test.