O desenvolvimento de métodos de simulação física e numérica tem criado novas possibilidades de otimização dos processos relacionados à estampagem com inclusão de processos industriais reais. Portanto, recorrendo à aplicação destes métodos de análise, é possível avaliar a transformação mecânica e as transformações de fase que ocorrem no material e prever as interações entre as propriedades dos materiais no processo de conformação, o comportamento constitutivo do material, as variáveis de otimização do processo, bem como a previsão das tensões e deformações a fim de estabelecer a melhor relação material-processo-desempenho. A introdução e crescente utilização de aços avançados de alta resistência (AHSS) em aplicações automotivas exige uma maior compreensão dos fenômenos físicos envolvidos no processamento termomecânico a fim de otimizar a performance da peça final fabricada. O presente trabalho teve como objetivo avaliar experimentalmente o processo de estampagem a quente, com posterior tratamento térmico de têmpera e partição e analisar as microestruturas formadas e suas propriedades mecânicas. A formação de microestruturas durante o processo de estampagem a quente e de têmpera e partição foi avaliada neste trabalho por simulação física em simulador termomecânico Gleeble, acoplado à uma linha de difração de raios X (XTMS) de feixe de luz síncrotron no Laboratório Nacional de Nanotecnologia (LNNano). Foram avaliadas a partição do carbono, a estabilidade térmica da austenita retida e a formação de microconstituintes resultantes da transformação da austenita durante resfriamento forçado (têmpera), seguido de partição de carbono em patamares isotérmicos. Foram utilizadas técnicas de caracterização com apoio de microscopia eletrônica (MEV-FEG e STEM), EBSD, tomografia de sonda atômica (APT) e avaliação de propriedades mecânicas por ensaios de tração e indentação instrumentada. A análise numérica foi realizada por meio do método dos elementos finitos (MEF) e por elementos finitos orientada a objetos (OOF, Object Oriented Finite Element Analysis) visando estabelecer correlações entre microestrutura e propriedades mecânicas, comparando com resultados experimentais. Os resultados e conclusões obtidos no projeto, além de possibilitarem a identificação dos mecanismos fundamentais de geração de microestruturas durante o processo, auxiliam no projeto de aços AHSS estampados a quente, usados principalmente na indústria automobilística, na busca pela redução do consumo de combustível, através da redução do peso, e pelo aumento da segurança dos passageiros. / The development of numerical and physical simulation methods has created new possibilities regarding the optimization of metal forming processes, taking into account real industrial forming processes. Therefore, by applying such methods of analysis it is now possible to assess the material phase transformations and predict the interactions between material properties and the forming process, the constitutive behavior of the material, and optimize process variables as well as predicting the best material-process-performance relationship. The increasing usage of Advanced High Strength Steels (AHSS) in automotive applications demands a better insight of the physical phenomena involved in the thermomechanical processing in order to optimize the performance of the final manufactured part. Thermomechanical simulation of the hot stamping, quenching and partitioning process was carried out in a Gleeble machine coupled to the XTMS Synchrotron X-ray diffraction line at the National Nanotechnology Laboratory (LNNano). Carbon partitioning, carbon contents, and amount of retained austenite, martensite, bainite and ferrite was assessed online during the experiments. In addition, characterization techniques by optical, electron microscopy (FEG-SEM and STEM), EBSD, and Atom Probe Tomography (APT) were applied. Mechanical testing of subsize specimens of the processed steels was performed by means of tensile tests and macro and nanoindentation tests. The numerical analysis was performed using the finite element method (FEM) and object-oriented finite element technique (OOF). The results were compared with the experimental results of mechanical testing of specimens used in the thermomechanical simulations and with hot stamped sheets, where quenching and partitioning were carried out. The results and conclusions obtained in this project allow the identification of the fundamental mechanisms of the process, helping the design of the hot stamping process for AHSS steels used primarily in the automotive industry, seeking weight reduction to improve fuel economy and increased passenger safety.

[pt] Os aços inoxidáveis Duplex são materiais metálicos que tendem a aliar uma excelente resistência à corrosão em meios agressivos com elevada resistência mecânica devido à sua microestrutura bifásica. Essa microestrutura é composta por uma matriz ferrítica e ilhas de austenita, a temperatura ambiente, com frações volumétricas aproximadamente iguais dessas duas fases. Com isso, estas ligas costumam ser utilizadas em tubulações e equipamentos industriais onde se requer elevada relação resistência/peso, especialmente em empreendimentos de construção e montagem off-shore. Este trabalho apresenta uma metodologia desenvolvida com a utilização de um modelo numérico parametrizado baseado no método de elementos finitos para analisar o efeito dos ciclos térmicos de soldagem nos aços duplex e leanduplex. O modelo desenvolvido faz uso da análise térmica transiente da soldagem, em que as propriedades térmicas dos materiais envolvidos são termo dependentes, e grandes gradientes térmicos são gerados entre a região da solda e as áreas afastadas dela. Procedimentos experimentais para medição dos ciclos térmicos empregados sob determinados regimes de soldagem são utilizados para calibrar o modelo numérico. A metodologia é aplicada ao estudo do comportamento de uma solda na forma de cordão sob chapa contendo um único passe, realizada com o processo GMAW, em chapas planas de 10mm de espessura dos aços duplex UNS32205 e leanduplex UNS32304, através de um modelo de elementos finitos. Os resultados mostram uma boa correspondência entre o modelo numérico e o resultado experimental. / [en] Duplex stainless steels are metallic materials that tend to combine excellent corrosion resistance in aggressive environment with high mechanical strength due to their biphasic microstructure. This microstructure is composed of a ferritic matrix and austenite islands, at room temperature, with approximately equal volume fractions of these two phases. As a result, these alloys are often used in pipes and industrial equipment where high resistance / weight ratio is required, especially in offshore assembly and construction field. This work presents a methodology developed with the use of a parameterized numerical model based on the finite element method to analyze the effect of thermal welding cycles on duplex and leanduplex stainless steels. The developed model uses the transient thermal analysis of welding, in which the thermal properties of the materials involved are thermo-dependent, and large thermal gradients are generated between the region of the weld and the areas away from it. Experimental procedures for measuring the thermal cycles employed under certain welding conditions are used to calibrate the numerical model. The methodology is applied to the study of the behavior of a weld in the form of a strand in sheet form containing a single pass, realized with the GMAW process, in flat plates of 10mm thickness of the duplex steels UNS32205 and leanduplex UNS32304, through a finite element model. The results show a good correspondence between the numerical model and the experimental result.

Les insectes ravageurs constituent depuis longtemps une menace sérieuse pour l’agriculture dans plusieurs régions du monde. En particulier, les criquets pèlerins (Schistocerca Gregaria) sont les plus redoutés à cause des dégâts colossaux qu’ils peuvent infliger à une large variété de cultures. Ces derniers, dans leur milieu de reproduction et un ensemble de paramètres climatiques, peuvent être assimilés à un système biophysique. Un système biophysique associe plusieurs composants caractérisés par leur complexité propre et celle de leurs interactions. Par exemple la pluie apporte de l’humidité et le développement du couvert végétal qui sont critiques dans la dynamique de population du criquet pèlerin. Ces systèmes biophysiques peuvent être contrôlés par divers moyens, dont un réseau de surveillance couplant des capteurs sans fil. L’intégration des systèmes biophysiques et des réseaux d’observation peut être un des faits majeurs de cette décennie. Elle permet un échange entre les processus cycliques physiques et les systèmes d’information. Ces derniers permettent de collecter et de traiter les données de terrain et peuvent aussi agir sur le système physique par le biais de boucles rétro-actives. Cette intégration a été possible grâce aux avancées technologiques notées dans les domaines de la micro électronique et de la transmission sans fil. On la trouve dans des domaines émergents tels que l’agriculture fine. Cette thèse est consacrée à la modélisation cellulaire et à la simulation de systèmes physiques. Pour cela, un échantillonnage spatial et temporel d’une zone de reproduction des criquets pèlerins a été réalisé à l’aide d’outils spécifiques avec différentes résolutions, dans le but de générer les systèmes cellulaires. Ces systèmes cellulaires contiennent des informations telles que le vent, la température, l’humidité relative et la pluviométrie. L’échantillonnage spatial permet une représentation de migration et l’échantillonnage temporel permet de suivre l’évolution locale des individus dans une cellule.Les systèmes cellulaires sont transcrits en réseaux de processus communicant et évoluent de manière synchrone afin de reproduire et de simuler le phénomène de migration intercellulaire et le cycle de vie du criquet pèlerin dans une cellule. La construction de ces systèmes a été explorée en profondeur, en faisant varier leur contexte géographique, les critères de classification, la dimension des cellules, la connectivité entre les processus, les comportements collectifs. L’exploration a porté sur la génération de codes parallèles et les performances à l’exécution, essentiellement pour le cas des processus légers.Ce travail a abouti à la production de deux simulateurs paramétriques, le premier est destiné à la dynamique de population des criquets pèlerins en vue d’évaluer l’état de la situation acridienne par un couplage entre les réseaux de surveillance synchrones et les systèmes biophysiques. Le second permet de planifier le déploiement de réseaux de capteurs sans fil dans une zone afin de déterminer l’emplacement des capteurs. / Insect pests have long been a serious threat to agriculture in many parts of the world. In particular, desert locusts (Schistocerca Gregaria) are the most feared because of the colossal damage they can inflict on a wide variety of crops.The latter, in their breeding environment and a set of climatic parameters, can be assimilated to a biophysical system. A biophysical system associates several components characterized by their own complexity and that of their interactions. For example, rain brings moisture and canopy development that is critical in Desert Locust population dynamics. These biophysical systems can be controlled by various means, including a monitoring network coupling wireless sensors. The integration of biophysical systems and observation networks can be one of the major events of this decade. It allows an exchange between physical cyclical processes and information systems. These can collect and process field data and can also act on the physical system through feedback loops. This integration has been made possible thanks to technological advances noted in the fields of microelectronics and wireless transmission. It is found in emerging fields such as fine agriculture. This thesis is devoted to cellular modeling and simulation of physical systems. For this, a spatial and temporal sampling of a Desert Locust breeding area was carried out using specific tools with different resolutions, in order to generate the cellular systems. These cellular systems contain information such as wind, temperature, relative humidity and rainfall. Spatial sampling allows a migration representation and temporal sampling can track the local evolution of individuals in a cell.Cellular systems are transcribed into communicating process networks and evolve synchronously to reproduce and simulate the phenomenon of intercellular migration and the life cycle of the Desert Locust in a cell. The construction of these systems has been explored in depth, making vary their geographical context, the criteria for classification, the cells, connectivity between processes, collective behaviors.Exploration has focused on the generation of parallel codes and performance at the execution, mainly for the case of lite processes.This work has led to the production of two parametric simulators, the first of which is aimed at Desert Locust population dynamics with a view to assessing the state of the locust situation through coupling between synchronous monitoring networks and biophysical systems. The second allows you to plan the deployment of wireless sensor networks in an area to determine the location of the sensors.

O desenvolvimento de métodos de simulação física e numérica tem criado novas possibilidades de otimização dos processos relacionados à estampagem com inclusão de processos industriais reais. Portanto, recorrendo à aplicação destes métodos de análise, é possível avaliar a transformação mecânica e as transformações de fase que ocorrem no material e prever as interações entre as propriedades dos materiais no processo de conformação, o comportamento constitutivo do material, as variáveis de otimização do processo, bem como a previsão das tensões e deformações a fim de estabelecer a melhor relação material-processo-desempenho. A introdução e crescente utilização de aços avançados de alta resistência (AHSS) em aplicações automotivas exige uma maior compreensão dos fenômenos físicos envolvidos no processamento termomecânico a fim de otimizar a performance da peça final fabricada. O presente trabalho teve como objetivo avaliar experimentalmente o processo de estampagem a quente, com posterior tratamento térmico de têmpera e partição e analisar as microestruturas formadas e suas propriedades mecânicas. A formação de microestruturas durante o processo de estampagem a quente e de têmpera e partição foi avaliada neste trabalho por simulação física em simulador termomecânico Gleeble, acoplado à uma linha de difração de raios X (XTMS) de feixe de luz síncrotron no Laboratório Nacional de Nanotecnologia (LNNano). Foram avaliadas a partição do carbono, a estabilidade térmica da austenita retida e a formação de microconstituintes resultantes da transformação da austenita durante resfriamento forçado (têmpera), seguido de partição de carbono em patamares isotérmicos. Foram utilizadas técnicas de caracterização com apoio de microscopia eletrônica (MEV-FEG e STEM), EBSD, tomografia de sonda atômica (APT) e avaliação de propriedades mecânicas por ensaios de tração e indentação instrumentada. A análise numérica foi realizada por meio do método dos elementos finitos (MEF) e por elementos finitos orientada a objetos (OOF, Object Oriented Finite Element Analysis) visando estabelecer correlações entre microestrutura e propriedades mecânicas, comparando com resultados experimentais. Os resultados e conclusões obtidos no projeto, além de possibilitarem a identificação dos mecanismos fundamentais de geração de microestruturas durante o processo, auxiliam no projeto de aços AHSS estampados a quente, usados principalmente na indústria automobilística, na busca pela redução do consumo de combustível, através da redução do peso, e pelo aumento da segurança dos passageiros. / The development of numerical and physical simulation methods has created new possibilities regarding the optimization of metal forming processes, taking into account real industrial forming processes. Therefore, by applying such methods of analysis it is now possible to assess the material phase transformations and predict the interactions between material properties and the forming process, the constitutive behavior of the material, and optimize process variables as well as predicting the best material-process-performance relationship. The increasing usage of Advanced High Strength Steels (AHSS) in automotive applications demands a better insight of the physical phenomena involved in the thermomechanical processing in order to optimize the performance of the final manufactured part. Thermomechanical simulation of the hot stamping, quenching and partitioning process was carried out in a Gleeble machine coupled to the XTMS Synchrotron X-ray diffraction line at the National Nanotechnology Laboratory (LNNano). Carbon partitioning, carbon contents, and amount of retained austenite, martensite, bainite and ferrite was assessed online during the experiments. In addition, characterization techniques by optical, electron microscopy (FEG-SEM and STEM), EBSD, and Atom Probe Tomography (APT) were applied. Mechanical testing of subsize specimens of the processed steels was performed by means of tensile tests and macro and nanoindentation tests. The numerical analysis was performed using the finite element method (FEM) and object-oriented finite element technique (OOF). The results were compared with the experimental results of mechanical testing of specimens used in the thermomechanical simulations and with hot stamped sheets, where quenching and partitioning were carried out. The results and conclusions obtained in this project allow the identification of the fundamental mechanisms of the process, helping the design of the hot stamping process for AHSS steels used primarily in the automotive industry, seeking weight reduction to improve fuel economy and increased passenger safety.

This master's thesis deals with physical simulation of cars. Program is implemented in C++ using OpenSceneGraph and Bullet libraries, which are shortly introduced. The application is implemented as simple racing game for one or two players. Using a simple menu, the user can select a car and the weather, which dramatically affects the handling characteristics of vehicles. Setting weather to random is one of the options leading to a dynamic weather changes during the game. The application takes into account collisions among cars and collisions with the terrain and bars on a racing circuit.

This thesis deals with the issue of creating applications of augmented reality. There are described types of augmented reality, problems associated with developing of applications of this kind. Also there is description of method for detection of moving objects from the record of stationary camera. The thesis deals with camera calibration using knowledge of scene geometry. Scene editor for scene geometry estimation is included in this work. Augmented reality is represented by physical simulations, where object from virtual reality interacts with detected objects and with objects defined in scene editor.

Background. In order to increase the visual fidelity of characters in video games, strand-based hair rendering within Unreal Engine 4 is explored in this thesis. Because of the complex nature of hair, explicit hair models can be very costly to render and simulate. It is theorized that utilizing customized hair and simulation settings, tailored to specific types of hairstyles could alleviate this issue while preserving visual fidelity. Objectives. The aim of this thesis is to provide an insight into what can be done to increase visual appeal and computer performance of physical simulation for different types of hairstyles and determine if customized settings may cause a significant impact on the perceived level of realism. The objectives of this thesis are to acquire a set of different strand-based hairstyles, determine a set of customized hair and simulation settings which can be applied to them, create a test scene inside of Unreal Engine 4 and render out a set of images and videos to be used in a user experiment, measure the performance of each customized setting and finally synthesize the acquired data. Methods. In order to achieve the aims and objectives of this thesis, a user experiment that utilizes the 2AFC method to let participants compare image- and video-pairs is performed as well as a performance experiment using the built-in profiling tools in Unreal Engine 4. In addition, a pilot experiment was performed in order to ascertain that the experiments would be feasible on the available hardware. Results. The results show that there was a significant difference in the perceived level of realism when different simulation settings was applied to the hairstyles, with customized settings being preferred to the default setting. The voting results on the image-pairs showed a preference for fine hair strands while the strand count did not have as much of an impact. It was shown that participants could easier distinguish between the different simulation- and hair-settings in long hair compared to short hair. The performance experiment showed that the amount of hair strands had the biggest impact on computer performance. Conclusions. Customizing hair and simulation settings to different types of hairstyles could provide a heightened perceived level of realism and a limited performance boost, from what could be derived from these experiments. Lowering the hair strand count was determined to be the most effective method of increasing performance. The performance of strand-based hair is currently not quite reaching a consistent 60 frames per second on the tested hardware, but with further optimizations it is believed that this could be acquired, especially on more powerful graphics cards. Future work should keep focus on increasing the stability of real-time strand-based hair simulation.

Background There exist an external demand forcing the manufacturing industry to increase their sustainable practice. For manufacturing companies to stay competitive it is necessary for them to transform their organization and operation to be more sustainably responsive. To meet the external demand for sustainable practice in the manufacturing industry, companies need to find new innovative solutions for their production processes.  Implementing new process innovations in production processes can be an uncertain task for companies to manage. To reduce the uncertainty, it is important to experiment with different solutions before implementation. To conduct experiments in an efficient and safe way, companies can use the tool simulation to validate process innovations before implementation.  There exist different simulation methods a company can use. Physical simulations are used when a company have production processes that cannot be simulated through a computer. Physical simulations are conducted in test facilities where companies can analyze material behavior in a laboratory scale production process.  Research questions RQ1: What need exists for test facilities in manufacturing companies?  RQ2: What benefits can be obtained using test facilities?  Aim A1: Identify stakeholder needs and based on these needs develop a conceptual test facility adapted to the case company.  Method To answer the research questions and fulfill the aim of the study, a literature review and a case study was conducted. The literature review explored the need and benefits of conducting physical simulations in test facilities when implementing new innovations in production processes to meet the demand for sustainability.  The case study was conducted at Volvo Construction Equipment in Hallsberg where the need to implement a test facility for their chemical production process was explored together with the benefits such a facility might contribute with. The case study also entailed information with stakeholder’s need for the development of a conceptual test facility to fulfill to the aim of the thesis.  Findings The findings suggest that there exists a need for implementing test facilities in manufacturing companies with chemical production processes. To transform production processes to meet external demands, companies must experiment with new innovations before implementation. A test facility could increase the efficiency when transforming and improving chemical production processes as well as strengthen the knowledge within the company for organizational development.  Furthermore, findings contributed with the development of a conceptual test facility adapted to the case company’s chemical production process. This facility was constructed increase the company’s ability for conducting quality and development test of their current state production process. / Bakgrund Det existerar ett yttre krav som tvingar tillverkningsindustrin att öka sin hållbarhet. För att tillverkande företag ska förbli konkurrenskraftiga är det nödvändigt att omvandla sin organisation och verksamhet för att bli mer hållbart lyhörd. För dem att bemöta de yttre kraven på hållbart utövande inom tillverkningsindustrin behöver företag hitta nya innovativa lösningar för sina produktionsprocesser.  Att implementera nya processinnovationer i produktionsprocesser kan vara en osäker uppgift för företag att hantera. För att minska osäkerheten är det viktigt att experimentera med olika lösningar innan implementering. För att genomföra experiment på ett effektivt och säkert sätt kan företag använda simulering för att validera processinnovationer innan implementering.  Det finns olika simuleringsmetoder som ett företag kan använda. Fysiska simuleringar används när ett företag har produktionsprocesser som inte kan simuleras via en dator. Fysiska simulering genomförs i testanläggningar där företag kan analysera materialbeteende i produktionsprocess i laboratorieskala.  Forskningsfrågor F1: Vilket behov för testanläggningar existerar i tillverkningsföretag?  F1: Vilka fördelar kan erhållas genom att använda testanläggningar?  Mål M1: Identifiera intressentbehoven och utifrån dessa behov utveckla en konceptuell testanläggning anpassad till företaget.  Metod För att svara på forskningsfrågorna och uppfylla målet med studien genomfördes en litteraturstudie och en fallstudie. Litteraturstudien undersökte behovet och fördelarna med att utföra fysiska simuleringar i testanläggningar när nya innovation i produktionsprocesser ska implementeras för att möta hållbarhetskraven.  Fallstudien genomfördes på Volvo Construction Equipment i Hallsberg där behovet av att implementera en testanläggning för deras kemiska produktionsprocess undersöktes tillsammans med vilka fördelar en sådan anläggning kan bidra med. Fallstudien medförde också information med intressenters behov vid utvecklingen av en konceptuell testanläggning för att uppfylla avhandlingens mål.  Resultat Resultaten tyder på att det finns ett behov av att implementera testanläggningar i tillverkande företag med kemiska produktionsprocesser. För att omvandla produktionsprocesser för att bemöta de yttre kraven måste företag experimentera med nya innovationer innan de implementeras. En testanläggning skulle kunna öka effektiviteten vid omvandling och förbättring av kemiska produktionsprocesser samt stärka kunskapen inom företaget för utveckling av organisationen.  Dessutom bidrog resultaten till utvecklingen av en konceptuell testanläggning anpassat till det studerade företagets kemiska produktionsprocess. Denna anläggning konstruerades för att öka företagets förmåga att genomföra kvalitets- och utvecklingstest av deras nuvarande produktionsprocess.

No description available.

Models (both physical and numerical) of the friction stir (FS) welding process are used to develop a greater understanding of the influence of independent process parameters on dependent process output variables, such as torque, power, specific weld energy, peak temperature, cooling rates and various metallurgical factors (e.g., grain size and precipitates). An understanding of how the independent process parameters influence output variables and ultimately their effect on resultant properties (e.g., strength, hardness, etc..) is desirable. Most models developed have been validated primarily for aluminum alloys with relatively small amounts of experimental data. Fewer models have been validated for steels or stainless steels, particularly since steels and stainless steels have proven more challenging to friction stir than aluminum alloys. The Gleeble system is also a powerful tool with the capability to perform thermomechanical simulations in a known and controlled environment and provide physical representation of resultant microstructure and hardness values. The coupling of experimental data and physical simulated data can be extremely useful in assessing the capabilities of friction stir numerical process models. The overall approach is to evaluate Isaiah an existing three-dimensional finite element code developed at Cornell University by comparing against experimental and physically-simulated data to determine how well the code output relates to real FS data over a range of nine processing conditions. Physical simulations replicating select thermomechanical streamline histories were conducted to provide a physical representation of resultant metallurgy and hardness. Isaiah shows promise in predicting qualitative trends over a limited range of parameters and is not recommended for use as a predictive tool but rather a complimentary tool, Once properly calibrated, the Isaiah code can be a powerful tool to gain insight into the process, strength evolution during the process and coupled with a texture evolution model may also provide insight into microstructural and texture evolution over a range for which it is calibrated.