A dinâmica evolutiva de margens passivas continentais tem sido alvo de debates no âmbito da tectônica global e a margem leste da América do Sul compõe uma série de bacias marginais que contêm o registro sedimentar de diversos estágios de desenvolvimento da zona costeira após a abertura do Oceano Atlântico. No nordeste do Brasil, evidências de tectônica pós-rifte têm sido apontadas em algumas áreas do embasamento precambriano e bacias sedimentares . Nestas bacias, predomina a ocorrência de depósitos neógenos e quaternários no topo das unidades sedimentares. Estes depósitos têm sua ocorrência estendida para a costa sudeste e norte do Brasil. A área que compreende atualmente a Bacia Paraíba representa a última ponte de ligação das placas sul-americana e africana, portanto é um sítio geológico de fundamental relevância para a discussão da evolução da margem passiva sul-americana. Desta forma, o presente estudo tem como objetivo geral estabelecer um modelo de evolução tectono-sedimentar da Bacia Paraíba do Cretáceo superior ao Quaternário a partir da integração de informações de superfície e subsuperfície. Para atingir este objetivo, foram definidas duas etapas de trabalho. Na primeira etapa, foi criado e aplicado um método que permitiu o mapeamento das unidades neógenas e quaternárias, visto que os mapas disponíveis da região nordeste não apresentam estas unidades discriminadas. Este método combinou dados aerogamaespectrométricos e geomorfométricos, e foi validado por dados de campo. Os procedimentos criados representam uma metodologia inovadora no campo do sensoriamento remoto e geofísica integrada, visto que nenhum trabalho até o momento unificou de forma quantitativa estas técnicas e aplicou para o mapeamento geológico. A metodologia pode ser reproduzida nas demais áreas da costa nordeste com ocorrência de depósitos neógenos e quaternários. Na segunda etapa, a integração do mapa geológico com dados de campo, perfis estratigráficos profundos e imagens de aerogeofísica e sensoriamento remoto, permitiu o estabelecimento de estágios de preenchimento da Bacia Paraíba. Considerando as evidências de contatos laterais abruptos entre unidades cretáceas e cenozoicas, as grandes mudanças de espessura de estratos em curtas distâncias, a correspondência entre os dados morfoestruturais, magnéticos e estruturais de campo, foi possível propor que uma sequência de eventos de subsidência e soerguimentos foi impulsionadora de processos deposicionais e denudacionais nesta bacia. Estes eventos tectônicos não ocorreram somente na fase inicial da separação dos continentes, eles se estenderam até muito depois da separação do Pangea. Os depósitos neógenos e quaternários apresentam estruturas de deformação extensional e compressional compatíveis com o regime regional de esforços extensionais de orientação N-S para o Cenozoico Superior. Estes eventos estão provavelmente associados à reativação de zonas de cisalhamento do embasamento precambriano adjacente durante o Quaternário Superior. Portanto, a Bacia Paraíba apresenta um diverso conjunto de evidências de que a margem passiva da América do Sul, pelo menos no nordeste do Brasil, foi afetada por eventos tectônicos pós-rifte, incompatíveis com o padrão de desenvolvimento de margens passivas continentais. / The evolutionary dynamics of continental passive margins has been the subject of discussion in the global tectonics scope and the eastern South America margin comprises a number of marginal basins containing sedimentary records of several development stages of the coastal zone after the opening of the Atlantic Ocean. Evidence of tectonic post-rift in northeastern Brazil has been identified in some areas of Precambrian basement and sedimentary basins. In these basins, it is predominant the occurrence of Neogene and Quaternary deposits on top of the sedimentary units. These deposits have extended occurrence to the southeastern and to the northern coasts of Brazil. The area that nowadays comprises the Paraíba Basin represents the last bridge connecting the South American and African plates, hence it is an essential geological site for discussion concerning the South American passive margin evolution. Thus, the present study has the general objective to establish a model of tectonic-sedimentary evolution of the Paraíba Basin from late Cretaceous to late Quaternary based on integration of surface and subsurface information. To achieve this goal, two work stages of were defined. In the first stage, it was created and applied a method that enabled mapping Neogene and Quaternary units, because the available maps of the northeastern region do not present these units separately. This method has combined airborne gamma-spectrometry and geomorphometric data, and it was validated using field data. The proposed procedures represent an innovative methodology in the branch of integrating remote sensing and geophysical research, since no work has yet quantitatively unified and applied these techniques for geological mapping. The methodology can be replicated in other areas of th e northeastern coast where Neogene and Quaternary deposits also occur. The second step corresponds to the integration of the geological map with field data, deep stratigraphic profiles and images of airborne geophysics and remote sensing, what enabled the establishment of fill stages in the Paraíba Basin. Considering the evidence of abrupt lateral contacts between Cretaceous and Cenozoic units, large changes in strata thickness over short distances, and the correlation between morphostructural, magnetic and structural data, it is possible to propose that a sequence of subsidence and uplift events were driving factors of depositional and denudational processes in this basin. These tectonic events occurred not only in the initial separation stage of the continents, they went on until well after the breakup of Pangea. The Neogene and Quaternary deposits reveal extensional and compressional deformation structures compatible with the regional N-S-oriented extension stress field. These events are probably associated to the reactivation of shear zones of the precambrian basement area during the Late Quaternary. Therefore, the Paraíba Basin presents a diverse set of evidences that the passive South America margin, at least in the northeastern region of Brazil, was affected by post-rift tectonic events incompatible with the development pattern of passive continental margins.

The constantly tightening emission regulations demand the engines to be moreefficient, to get more power out of smaller engines. Higher engine loads andcomponent temperatures are causing more stresses to engine components. Therefore,a company that produces engines wanted to study if it would be possible to increasethe capabilities of the components by optimising the used material. In this final project work, a cylinder head will be studied. The cylinder heads for theengines are made of ductile cast iron. The limits of that material are near safety limits,and therefore a better material is needed. In this work are some previous studiesanalysed and tried to find how to optimise the used material. The optimised materialshould have better thermal conductivity properties combined with sufficient strengthproperties. Previous studies were analysed to gather knowledge of the elements that affect thematerial parameters. Those studies showed that copper, silicon, pearlite fraction, andthe use of chills are the elements to be optimised. Silicon and pearlite fraction waschosen as optimisation parameters because of their effect on the thermal conductivityand strength properties. Copper was chosen as an optimisation variable due to its effecton the pearlite formation. Chills were used to affect the cooling rate and thereby thepearlite formation. The work was made using MAGMASOFT™ simulation software to simulate cylinderhead casting. The simulated cylinder head was divided into 4 parts for the simulations.For those sections were then set targets for pearlite fraction according to previousstudies. The silicon content was kept constant in the simulation, based on the studiespresented in this work. Copper content was simulated with variations from 0 to 0.7weight-%, and chill heights were simulated from 20 to 60 mm and without chills. After simulating the different variables, the results were analysed. Then the selectedcasting simulation result was mapped to finite element simulation mesh to include thelocal material parameters to finite element simulation. With the finite elementsimulation, the estimated lifetime of the component was simulated. By analysing the casting simulation results, an optimal combination was found. Theoptimal material parameters for a cylinder head casting would be copper 0.5weight-%, silicon 1.9 weight-% and chills thicker than 40 mm on the flame plate. Theoptimised material gives more possibilities to develop engines even further when thecomponent demands are growing.

While using iron castings behind temperature of 500 C namely at cyclic heat straining degradation of structure and breaching iron castings. For this purpose introduce cast iron with content of Si and Mo. Focusing on improvement of SiMo51 for increased high-temmperature corrosion-and fatigue life in exhaust-gas temperatures up to 800 C. Thesis set up chemical microheterogeneity, properties, high temperature corosion and microhardness

The master‘s thesis deals in theoretical part with the casting classification, ductile iron casting, its inoculation and modification and quality evaluation using thermal analysis, image analysis and testing of mechanical properties. The aim of the practical part was to test the effects of preconditioning on the properties of ductile iron and to find out whether it is able to replace the current method of inoculation or to increase the mechanical properties of ductile iron castings. The state of the ductile iron was under control by spectral and thermal analysis. The mechanical properties and image analysis were checked on finished casting.

Táto diplomová práca sa zaoberá možnosťami výpočtového modelovania valcovania v kalibroch pomocou metódy konečných prvkov. Na začiatku je formulovaná motivácia pre písanie práce a problémová situácia, nasledovaná zostavením systému podstatných veličín. Ďaľšia kapitola popisuje rôzne spôsoby valcovania ako aj samotný valcovací proces. Dôraz je kladený na popis tradičného návrhu kalibrov. Nasledujúca kapitola sa zaoberá teóriou plasticity, plastickým chovaním materiálu a jeho modelovaním v konečnoprvkovom prostredí Abaqus, ktoré je použité vo výpočtovej časti práce. Predstavené sú viaceré modely plasticity, ako aj modely tvárneho porušovania, používané na posúdenie tvárniteľnosti či simuláciu šírenia tvárnej trhliny v materiáli. Práca pokračuje kapitolou zameranou na metódu konečných prvkov, najmä jej explicitný algoritmus, využívaný vo výpočtovej časti práce. Ďaľšia časť je venovaná popisu základných princípov fotoelasticimetrie, tradičnej experimentálnej metódy. Tieto kapitoly zahŕňajú aj popis konečnoprvkovej a experimentálnej fotoplastickej analýzy konkrétneho prípadu valcovania v kalibroch, riešené v predchádzajúcom článku. Použitý výpočtový model je základom nového konečnoprvkového modelu, ktorého tvorbe je predmetom nasledujúcej kapitoly. Naviac sú vytvorené aj dve varianty pôvodného, zjednodušeného výpočtového modelu. S použitím vytvorených výpočtových modelov sú vykonané štrukturálne analýzy a vyhodnotené viaceré výsledky, následne zhrnuté a porovnané s pôvodnými výpočtovými a experimentálnymi výsledkami. Rozbor porovnania výsledkov a zhodnotenie použiteľnosti a spoľahlivosti jednotlivých výpočtových modelov tvoria záver práce.

This thesis describes the complete technology solution of front driving axle console production by machining. The console is part of the self-supporting structure of the tractor and is produced under conditions of large engineering company. Introduction describes the prduction technology of component. The main part is devoted to the technological process of production and selection of appropriate cutting tools. Technical and economical evaluation of machined part is mentioned in the conclusion of thesis.

This master´s thesis deals with the evaluation of fracture behavior of ODS steel MA956 at high temperature range. This behavior was tested by using miniaturized CT specimens, on which were performed experiments to measure of ductile crack growth resistance curves (J-R curves). The value of the fracture toughness was determined from these J-R curves. Fracture properties were consequently evaluated by using fractographic analysis of the fracture surfaces. Structural properties of material was identified by hardness measurement and analyzed by metallographic methods. Results of the measurements show drop of the fracture toughness with respect to the increasing temperature.

No description available.

The issue of ductile damage prediction can be generally divided in two types of tasks. The first one is to preventing the initiation of ductile damage with is most common group of calculation today. The second task can be described as aimed damaging, such as machining, cutting, etc. The significant development of this issue occurred in recent decades by help of development and access to powerful computational techniques and new experimental possibilities. However, the behaviour of ductile damage at multiaxial proportional and non-proportional loading is insufficiently described. This thesis helped to clarify some of the unknown this topic. It contributed to the understanding of selected materials behaviour at room temperature and quasistatic loading. Austenitic stainless steel AISI 316L was selected for detail study of ductile damage. A large number of experiments were performed on this material, such as uniaxial tensile tests of smooth and notched specimens, upsetting tests of smooth cylinder and special cylinder with dimple, butterfly specimens, notched tube specimens and penetration tests. Experimental results is used for calibration of five so-called simple criteria, taking into account fracture strain and stress triaxiality (Equivalent fracture strain, Johnson-Cook, simplify Bao-Wierzbicki, RT, RTCL) and universal criteria (Bai-Wierzbicki, Xue-Wierzbicki, EMC, LOU, KHPS). SPT potentially enable the determination of actual mechanical behaviour using only a fraction of specimen volume compared to standard specimen. It is promising tool to improve accuracy when assessing working life of components in operation. The inverse numerical simulation loop of SPT was designed using program OptiSLang on the basis of detailed sensitivity analysis. It was achieved 2% deviation of yield strength and 6% deviation of ultimate strength obtained from tensile tests. A several modification of SPT specimen was suggested for universal criteria calibration of small material volume. The 3D numerical model was built for numerical simulation with ductile damage simulation. The criteria KHPS and EMC gave the most accurate results.

No description available.