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Le creuset est une structure majoritairement composée de matériaux réfractaires destinés à supporter de fortes sollicitations thermomécaniques, dues au contact direct de ses parois internes avec la fonte à 1500°C. L’objectif de cette thèse est de développer un modèle thermomécanique de creuset capable de localiser les zones sensibles de la structure et d’estimer les contraintes. Des blocs de carbone, des structures maçonnées (briques avec mortier) et un pisé carboné sont les principaux constituants du creuset. Afin d’identifier leur comportement, des essais de caractérisation ont été développés pour des températures atteignant les 1500°C. Un modèle de type Cam-Clay modifié est proposé pour modéliser le comportement compactant du pisé. L’influence de la température et des fortes pressions est prise en compte. Une bonne corrélation est obtenue entre les résultats expérimentaux et numériques. Les structures maçonnées, en contact direct avec la fonte, sont fortement sollicitées, ce qui peut conduire à l’ouverture des joints de mortier. La modélisation proposée pour ces structures est basée sur une approche micro-macro où les briques et le mortier sont remplacés par un matériau homogène équivalent, et ce pour différents états d’ouverture de joints. La non-linéarité du comportement est reproduite grâce à un critère d’ouverture en contrainte, qui permet le passage d’un état à un autre. Les propriétés homogénéisées sont obtenues par homogénéisation périodique en s’appuyant sur une approche énergétique. La modélisation d’un essai de la littérature permet la validation du modèle. La modélisation finale du creuset est confrontée aux résultats de l’instrumentation d’un creuset. Une bonne concordance entre ces résultats est obtenue. / The blast furnace hearth is mainly composed of refractory materials to support strong thermo-mechanical loads. Indeed, there is a direct contact between its internal walls and the molten pig iron at 1500°C. The objective of this thesis is to develop a thermo-mechanical model able to locate the sensitive areas and to estimate the stress fields. Carbon blocks, masonries (bricks and mortars) and a carbon ramming mix are the main constituents of the hearth. In order to identify their behaviours, characterization tests have been developed for temperatures up to 1500°C. A modified Cam-Clay model is proposed in order to reproduce the hardening behaviour of the ramming mix. The influences of temperature and pressure are taken into account. Experimental and numerical results are in good agreement. Masonries, submitted to high temperature gradients are highly stressed, which can lead to the opening of the mortar joints. The proposed masonry modelling is based on a micro-macro approach where bricks and mortars are replaced by an equivalent homogenous material for different joint states. The non-linearity of the behaviour is reproduced thanks to a stress criterion, allowing the transition from one state to another. Homogenized properties are obtained by periodic homogenization with an energetic approach. The modeling of a shear test available in the literature allows the validation of this model. The final modelling of a hearth is compared with in-situ instrumentation results. A good agreement is reached between these results.

Master's thesis deals with the Red Hill, a place situated inside the urban area of Brno, close to the historic center, close to the newly established and still growing campus of Masaryk University. Red hill with its gardening colony remains blank space on the map of Brno, the goal here was to create a functional urban structure that would place the space in the city map. Not to make an urban mash on the peripherals, but build a real city organism into the hearth of the city Brno.

This study has focused on determining the heat flows in a production blast furnace hearth. This part of the blast furnace is exposed to high temperatures. In order to increase the campaign length of the lining an improved knowledge of heat flows are necessary. Thus, it has been studied both experimentally and numerically by heat transfer modeling. Measurements of outer surface temperatures in the lower part of a production blast furnace were carried out. In the experimental study, relations were established between lining temperatures and outer surface temperatures. These relations were used as boundary conditions in a mathematical model, in which the temperature profiles in the hearth lining are calculated. The predictions show that the corner between the wall and the bottom is the most sensitive part of the hearth. Furthermore, the predictions show that no studied part of the lining had an inner temperature higher than the critical temperature 1150°C, where the iron melt can be in contact with the lining. / QC 20101124

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Medieval dwelling houses of a similar type have been documented on Gotland in archaeological investigations. They all have common planning, a rectangular house foundation divided into two rooms and a square-shaped fireplace which is located in one of the corners. In this study the aim is to find out when this type of building was first introduced on Gotland as well as why it was adopted. Another aim is to compare the gotlandic houses with similar buildings from other places in Scandinavia? The method used to answer these questions consists of a comparison between visually similar houses from Gotland and the mainland based on orientation, dimensions, construction and dating. The comparison shows that the majority of the foundations investigated frequently are oriented west east, that the average dimensions are approximately 8 × 6 m and that the houses approximately can be dated between the 12th and 13th century.

Die vorliegende Arbeit untersucht den Einsatz einer induktiven Längsfelderwärmung im Wärmebehandlungsprozess der direkten Warmumformung automobiler Karosserieblechbauteile. Zur Charakterisierung des Erwärmungsvorgangs werden sowohl experimentbasierte Regressionsmodelle als auch ein FEM-Simulationsmodell entwickelt. Der Einfluss der induktiven Erwärmung auf die Ausbildung der AlSi-Beschichtung, die Widerstandspunktschweißbarkeit so-wie die Korrosionsbeständigkeit gefertigter Blechbauteile wird dargelegt. Abschließend wird ein Anlagenkonzept entwickelt, das durch den Einsatz der induktiven Längsfelderwärmung eine Verringerung der Erwärmungsdauer um etwa 50 % sowie eine Verkürzung der erforderlichen Ofenlänge um etwa 37 % ermöglicht. / The present thesis investigates the usage of longitudinal induction heating in the austenitization process of direct press hardening. In order to describe the induction heating procedure, experiment-based regression models as well as a FEM model are developed. The influence of an induction heating process on the properties of press hardened parts with aluminum-silicon coating is depicted. Therefore, resistance spot welding tests, paint adhesion tests and corrosion tests are performed. Finally, a heating concept for series production including a longitudinal induction heating is developed, which allows a decrease in heating time of about 50 % and a reduction of furnace length of about 37 %.

Il lavora affronta l'analisi delle strutture di combustione provenienti da diversi contesti archeologici attraverso un approccio multidisciplinare. Le metodologie adottate associano all'approccio contestuale i risultati derivati dall'analisi archeobotanica dei residui di combustione e delle alterazioni termiche. Lo studio tipologico delle strutture di combustione è integrato dai risultati della riproduzione sperimentale delle strutture in modo da selezionare le metodologie di analisi e di intervento nei cantieri archeologici. L'analisi dei resti vegetali (analisi antracologica, carpologica, tafonomica) ha permesso inoltre di ricostruire le strategie ed aree di approvvigionamento del combustibile, il paleoambiente, la paleodieta ed alcuni aspetti dell'agricoltura delle comunità del passato. Tale approccio è stato applicato alla lettura ed interpretazione delle attività connesse con l'uso del fuoco e gestione degli spazi in alcuni contesti archeologici indagati dall'Università del Salento: santuario di Apollo a Hierapolis (Turchia), abitato dell'età del Ferro e fase arcaica di San Vito dei Normanni, abitato dell'età del Ferro di Castelluccio. / This work analyzes the hearth structures from different archaeological contexts through a multisciplinary approach. The contextual analysis is linked to archaeobotanical analysis of fuel and thermal alteration. The experimental replica of hearth structures shed new light about new methodology of studies and definition of proceedings protocol. This approach is applied to three archaeological sites excavated by the University of Salento: Apollo sanctuary at Hierapolis (Turkey), San Vito dei Normanni (Brindisi, South Italy), Castelluccio (Brindisi, South Italy). The archaeobotanical analysis (anthracological, carpological, taphonomical analysis) allowed to reconstruct fuel management, palaeoenvironment, paleodiet and agricolture practice of ancient comunities.

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