Este trabalho tem a intenção de contribuir com informações sobre a integridade superficial resultante do processo de torneamento em material endurecido de componentes mecânicos fabricados em aço cementado ABNT 8620 (DIN 21 NiCrMo 2). A análise das tensões residuais do corpo de prova foi experimentalmente conduzida pelo Método do Furo Cego Incremental, no qual um pequeno furo é introduzido na superfície do componente e a deformação aliviada é registrada por meio de extensômetros especiais, e também, pelo método da difração de raios-X. A superfície foi analisada através de parâmetros obtidos do mapeamento tridimensional da topografia superficial com instrumento de interferometria laser. Os parâmetros de rugosidade, selecionados para medição, visaram uma caracterização funcional das superfícies obtidas, tais como capacidade de carga, capacidade de retenção de fluidos lubrificantes e resistência ao desgaste. Também foram executados ensaios metalográficos para avaliar a existência de camadas de material alteradas abaixo da superfície. Os resultados indicaram que o torneamento em material endurecido foi capaz de produzir uma superfície resultante com boa área de contato, boa capacidade de carregamento e razoável capacidade de retenção de fluidos uma vez que nem todos os parâmetros se encontraram na faixa funcional ideal. O torneamento em material endurecido induziu tensão de compressão nas camadas das amostras cementadas, cuja condição original era tensão residual de tração. Não foram detectadas alterações expressivas na camada cementada, principalmente na região limítrofe da área transversal com a superfície devido ao aquecimento e rápido resfriamento imposto pelo processo de usinagem. / The aim of the present work is to provide relevant information regarding the obtained surface integrity during hard turning process of mechanical components manufactured from case hardened steel ABNT 8620 (DIN 21 NiCrMo 2). The sample residual stress analysis has been experimentally conducted by the incremental Blind Hole method, in which a small hole is machined on the surface of the component and the relieved deformation is recorded through special strain gages, and by the X-ray diffraction technique. The surface was examined by parameters obtained from the surface topography three-dimensional mapping with a laser interferometer instrument. The selected roughness parameters analysis intends to have a functional characterization such as bearing capacity, fluid and lubricants retention ability and contact wear resistance. In the search for altered material layers beneath the surface, metallographic studies were carried out. The functional bearing area curve analysis parameters indicated that the resulting surface has a good area contact, good bearing capacity and reasonable ability to fluid retention as the reduced valley depth parameter did not produced negative values for all conditions tested. The hard turnig process was able to add compression residual stress condition at the surface, and no significant changes were found at the case hardened layer due to rapid heating and cooling imposed by the hard turning process.

Dans cette thèse, nous nous sommes intéressés à l'analyse locale de systèmes différentiels linéaires singulièrement perturbés et de systèmes de Pfaff complètement intégrables et multivariés à croisements normaux. De tels systèmes ont une vaste littérature et se retrouvent dans de nombreuses applications. Cependant, leur résolution symbolique est toujours à l'étude. Nos approches reposent sur l'état de l'art de la réduction formelle des systèmes linéaires singuliers d'équations différentielles ordinaires univariées (ODS). Dans le cas des systèmes différentiels linéaires singulièrement perturbés, les complications surviennent essentiellement à cause du phénomène des points tournants. Nous généralisons les notions et les algorithmes introduits pour le traitement des ODS afin de construire des solutions formelles. Les algorithmes sous-jacents sont également autonomes (par exemple la réduction de rang, la classification de la singularité, le calcul de l'indice de restriction). Dans le cas des systèmes de Pfaff, les complications proviennent de l'interdépendance des multiples sous-systèmes et de leur nature multivariée. Néanmoins, nous montrons que les invariants formels de ces systèmes peuvent être récupérés à partir d'un ODS associé, ce qui limite donc le calcul à des corps univariés. De plus, nous donnons un algorithme de réduction de rang et nous discutons des obstacles rencontrés. Outre ces deux systèmes, nous parlons des singularités apparentes des systèmes différentiels univariés dont les coefficients sont des fonctions rationnelles et du problème des valeurs propres perturbées. Les techniques développées au sein de cette thèse facilitent les généralisations d'autres algorithmes disponibles pour les systèmes différentiels univariés aux cas des systèmes bivariés ou multivariés, et aussi aux systèmes d''equations fonctionnelles. / In this thesis, we are interested in the local analysis of singularly-perturbed linear differential systems and completely integrable Pfaffian systems in several variables. Such systems have a vast literature and arise profoundly in applications. However, their symbolic resolution is still open to investigation. Our approaches rely on the state of art of formal reduction of singular linear systems of ordinary differential equations (ODS) over univariate fields. In the case of singularly-perturbed linear differential systems, the complications arise mainly from the phenomenon of turning points. We extend notions introduced for the treatment of ODS to such systems and generalize corresponding algorithms to construct formal solutions in a neighborhood of a singularity. The underlying components of the formal reduction proposed are stand-alone algorithms as well and serve different purposes (e.g. rank reduction, classification of singularities, computing restraining index). In the case of Pfaffian systems, the complications arise from the interdependence of the multiple components which constitute the former and the multivariate nature of the field within which reduction occurs. However, we show that the formal invariants of such systems can be retrieved from an associated ODS, which limits computations to univariate fields. Furthermore, we complement our work with a rank reduction algorithm and discuss the obstacles encountered. The techniques developed herein paves the way for further generalizations of algorithms available for univariate differential systems to bivariate and multivariate ones, for different types of systems of functional equations.

Dans ce travail nous démontrons un théorème de simplification uniforme concernant les équations différentielles ordinaires du second ordre singulièrement perturbées au voisinage d’un point dégénéré, appelé point tournant. Il s’agit d’une version analytique d’un résultat formel dû à Hanson et Russell, qui généralise un théorème connu de Sibuya. Pour traiter ce problème, nous utilisons les développements asymptotiques combinés Gevrey introduits par Fruchard et Schäfke. Dans une première partie nous rappelons les définitions et théorèmes principaux de cette récente théorie. Nous établissons trois résultats généraux que nous utilisons ensuite dans la seconde partie de ce manuscrit pour démontrer le théorème principal de réduction analytique annoncé. Enfin nous considérons des équations différentielles ordinaires d’ordre supérieur à deux, singulièrement perturbées à point tournant, et nous démontrons un théorème de réduction analytique. / In this thesis we prove a theorem of uniform simplification for second order and singularly perturbed differential equations in a full neighborhood of a degenerate point, called a turning point. This is an analytic version of a formal result due to Hanson and Russell, which generalizes a well known theorem of Sibuya. To solve this problem we use the Gevrey composite asymptotic expansions introduced by Fruchard and Schäfke. In the first part we recall the main definitions and theorems of this recent theory. We establish three general results used in the second part of this thesis to prove the main theorem of analytic reduction. Finally we consider ordinary differential equations of order greater than two, which are singularly perturbed and have a turning point, and we prove a theorem of analytic reduction.

Lors de l’usinage, les conditions de pression et de température à la surface usinée sont trèsélevées. La microstructure et l’état mécanique du matériau sont impactés, ce qui a desconséquences sur la réactivité chimique de la surface usinée. Dans cette thèse, ons’intéresse au tournage de superfinition de l’acier inoxydable martensitique X4CrNiMo16-5-1traité thermiquement (dénommé APX4 optimisé). Il présente la particularité d’êtremultiphasé à la température ambiante (martensite, ferrite et austénite). L’objectif est dequantifier les relations entre les conditions de coupe, les propriétés d’usage et ladégradation par corrosion des surfaces usinées. Des essais d’usinage en coupe orthogonale(type QST) ont été réalisés afin de comparer directement les résultats expérimentaux auxprédictions numériques 2D des surfaces usinées.Les changements de phase du matériau ont été étudiés par des essais de calorimétriejusqu’à 1200°C. Les cycles thermiques réalisés ont mis en évidence différentestransformations métallurgiques. L’étude bibliographique complémentaire permet deconclure quant aux possibilités de transformation de phase en usinage, qui sont quasiinexistantes du fait des cinétiques de chauffage extrêmement élevées en tournage.Les échantillons usinés ont été caractérisés avec une étude microstructurale parmicrographie optique et par MEB-EBSD. Ces deux techniques mettent en évidence lesdéformations importantes en extrême surface indiquées par l’étirement des îlots de ferriteparallèlement à la surface usinée. Ces résultats microstructuraux ont été mis en relationavec les résultats de microdureté Vickers. Une relation de la dureté superficielle a étéexprimée en fonction des conditions de coupe. La technique EBSD a permis de montrer pourles échantillons usinés dans les conditions les plus sévères la déformation de la ferrite avecapparition de sous-joints de grain, un affinement microstructural de la martensite et uneaccentuation de l’affinement de la matrice martensitique à proximité de la ferrite déformée.Une simulation numérique de prédiction des déformations à l’échelle macroscopiquea été réalisée. Ces résultats numériques ont été comparés aux résultats de déformation etde microdureté issus d’une campagne d’essais. Des essais numériques complémentairesappliqués à l’échelle de la microstructure (matériau considéré biphasé) permettent ded’appréhender la déformation de la phase ferritique et son influence locale sur ladéformation de la matrice martensitique. Ces résultats sont cohérents avec les résultatsexpérimentaux.Les phénomènes de corrosion par piqûres ont été étudiés par le biais d’essais depolarisation à l’aide de la microcellule électrochimique et d’essais spécifiques pulsés. Cesderniers essais ont permis l’analyse des piqûres générées (en diamètre et en densité). Larésistance à la corrosion localisée des surfaces d’acier inoxydable martensitique reste bonneaprès usinage, même améliorée (densité de piqûres plusieurs fois plus faible que l’état deréférence). Ce comportement est corroboré à l’état de compression de la surface.La microdureté de surface, qui est contrôlée majoritairement par l’avance, conditionne lepotentiel de piqûre. L’augmentation du diamètre de piqûre a été reliée à l’affinementmicrostructural (observé à partir d’un certain seuil de microdureté superficielle). / During machining, pressure and temperature conditions at the machined surface are veryintensive. Machined material microstructure and mechanical state are changed, whichimpacts the chemical reactivity of the machined surface. In this PhD study, we focus onsuperfinish turning of heat treated martensitic stainless steel X4CrNiMo16-5-1 (namedoptimized APX4). It has to be mentioned that this material has a multiphased microstructureat ambient temperature (martensite, ferrite and austenite). The aim is then to quantifyrelationships between cutting conditions, properties and the deterioration (corrosion) ofmachined surfaces. Machining trials in orthogonal cutting configuration (QST) have beenrealized in order to compare experimental results directly to 2D numerical forecast ofmachined surfaces.Material phase transformations have been studied by calorimetry tests until 1200°C. Testshave evidenced different metallurgical transformations. The complementary bibliographystudy allows to conclude that phase transformation possibilities during machining are veryquasi nonexistent due to extremely high heating kinetics in turning.Machined samples have been characterized by a microstructural study by opticalmicrography and SEM-EBSD. Both techniques highlight high strains in extreme machinedsurface as indicated by the stretching of ferrite islands in parallel to the machined surface.Microstructural results have been linked to the Vickers microhardness results. Surfacehardness has been expressed as a function of the cutting conditions.EBSD measurements have shown for machined samples in the most severe conditionsstraining of the ferrite with low angle grain boundaries, microstructural refining ofmartensite and heightening of martensitic matrix close to the strained ferrite.A numerical simulation predicting strains at the macroscopic scale has been carried out.These numerical results have been compared to strain and microhardness results arise fromone trials campaign. Further numerical simulations applied at the microstructure level(considered as biphased material) allow understanding of ferritic phase strain and its localinfluence on martensitic matrix strain. These results are consistent with experimentalresults.Pitting corrosion phenomenon has been studied by polarization testing using theelectrochemical microcell and specific pulsed testing. Last used method has been conductedto analyze the generated pits (diameter and density). Localized corrosion resistance ofmachined martensitic stainless steel surfaces remains good, even improved (few times lowerpitting density than the reference state). This behaviour is corroborated to the compressivestate of the surface.Surface microhardness, which is mainly controlled by the feed rate, conditions the criticalpitting potential. Increased pitting diameter has been linked to microstructural refining(observed above a surface microhardness level).

The thesis aims to assess the feasibility of the business plan of pre-paid model of tasting of Moravian wine and judge whether it pays off to invest into this business plan. The feasibility study serves to confirm the execution of the business plan. The study describes the establishment of limited liability company and activities that are related to its establishment. It analyzes the environment through PEST analysis and Porter's five forces model. Market research is conducted via a survey, which serves as a basis for determination of an estimate of potential customers. Marketing mix allows to describe the product, pricing, distribution, promotion plan and marketing communications. The final price is determined using the calculation formula. The opening balance sheet of the company is prepared within this thesis. The amount of capital, the costs and sources of funding are determined. The financial plan includes estimated revenue, profit, return on equity and cash flow plan for the first two years of the life of the company.

The diploma thesis is focused on the design and evaluation of the concrete monolithic ceiling slab in the shape of semicircular ring, ribs lining this plate and skylights. The result is static calculation and drawing documentation.

The subject of this diploma thesis is the design of a pre-station area near the railway station Uherský Ostroh on track 340: Brno - Veselí nad Moravou and its connection to existing roads. The work alternatively addresses the method of connecting the area to the road I/55 in the build-up area of the town, the arrangement of parking and bus stops. Part of the design is also the connection of the area for the needs of pedestrians and suggests places for parking bicycles.

The diploma thesis deals with the influence of machining technologies (turning, milling, grinding and polishing) on the surface texture of functional surfaces of selected materials from technical plastics. In the first part of the thesis there is a theoretical analysis of the possibilities of machining plastic materials. Furthermore, an analysis of the most commonly used parameters for evaluating the roughness of the machined surface and their effect on functionality is performed. The experimental part of the thesis describes samples preparation, analysis of measured data and subsequent evaluation with benefits for machinery industry.

This document is about the work conducted during four months in the company Poclain Hydraulics. The aim was to improve the productivity of the turning operation on the cams MK04, in a factory environment but with the support of a laboratory. Was also in mind to improve the quality of the part and diminish or eliminate the unbroken chips. In that purpose the trajectories have been analyzed and modified, the cutting conditions studied and adapted, some tool changed, etc. The final result was an improvement of productivity to 140%, an amelioration of the chip breaking and of the part’s quality, leading to significant savings on the process.

This diploma thesis deals with the proposal of a single box girder bridge of three spans in the town Blansko. It bridges the river Svitava and the main railway Praha - Brno. The calculations were carried out by hand, the model was created in the Scia Engineer programme. The thesis also describes the solving of a complicated phased construction with the necessity of turning the bridge into the final position. The construction is considered by Eurocodes.