Fundação de Amparo a Pesquisa do Estado de Minas Gerais / This work presents the development of a learning platform for testing the three-phase induction motors. The project is the implementation and automation of a mechanical bench for testing in electrical machines with power less than 5HP. The developed bench allows user interaction, gradual and assisted in all stages, ie, from the design of the electric machine to the experimental verification of the dynamic behavior of the tested machine. Teaching resources from educational are illustrated by the results obtained with the control of a dc machine operating as a generator driven by three-phase induction motor. With this stand it is possible to perform significant tests to determine the performance of electric motors, such as measuring voltages and stator currents, speed, torque and power on to the motor shaft, beyond the graphics of torque and current versus speed , power and efficiency versus applied load factor. To drive and processing of information obtained (measures), uses a data acquisition system controlled by an application developed specifically for this work in graphical programming using the \"LabVIEW \" software. The study was conducted in steps like the following description: literature review study of NBR 5383-1(2002) (Brazilian rules of electrical machines), study and simulation of induction motors, physical design of the bench, specification of sensors and equipment, assembly and implementation of the testing manager application. / Neste trabalho apresenta-se o desenvolvimento de uma plataforma didática para ensaios de motores de indução trifásico. O projeto consiste na implementação e automação de uma bancada mecânica para ensaios de motores elétricos com potência de até 5CV. A plataforma desenvolvida permite uma interação do usuário, gradual e assistida, em todos os estágios dos ensaios, ou seja, desde a escolha do tipo da máquina elétrica até a verificação experimental do comportamento dinâmico da máquina ensaiada. Os recursos didáticos da ferramenta educacional são ilustrados com resultados obtidos com o controle de uma máquina de corrente contínua, operando como gerador acionada por um motor de indução trifásico. Com esta bancada é possível a realização de testes relevantes para determinação de desempenho dos motores elétricos, como a medição de tensões e correntes de estator, velocidade, conjugado e potência no eixo da máquina ensaiada, além da obtenção das curvas de conjugado e corrente versus velocidade, fator de potência e rendimento versus carga aplicada. Para acionamento e processamento de informações obtidas (mensuradas), utiliza-se um sistema de aquisição de dados controlado por um aplicativo desenvolvido especificamente para este trabalho na linguagem de programação gráfica ―LabVIEW ‖. O trabalho foi desenvolvido nas seguintes etapas: levantamento bibliográfico, estudo da Norma NBR 5383-1(2002), estudo e simulação dos motores de indução trifásicos, projeto físico da bancada, especificação dos sensores e equipamentos, montagem da bancada e implementação do aplicativo gerenciador dos ensaios. / Mestre em Ciências

La morphologie des os longs est affectée par les charges mécaniques qu'ils subissent, telles celles générées par les comportements locomoteurs. Dans ce mémoire, des images de coupes transversales de fémurs, tibias et humérus obtenues par CT-scan ont été analysées pour déterminer la locomotion de l'enfant de Dikika, un Au. afarensis juvénile, en se basant sur des comparaisons d'humains et de grands singes africains. Les résultats indiquent que le fémur de l'enfant de Dikika montre des signes de bipédie, mais ce n'est pas le cas du tibia. Malgré le fait que la forme de l'humérus est très similaire aux grands singes africains, la résistance de celui-ci aux tensions et torsions laissent supposer que l'enfant de Dikika ne pratiquait pas les locomotions typiques des grands singes comme l'arboricolisme ou encore la quadrupédie terrestre. Malgré tout, certains résultats montrent que la morphologie osseuse dépend aussi des processus ontogéniques et de la génétique de chaque taxon. / The morphology of long bones is affected by the mechanical loads they incur, such as those generated by locomotor behaviors. In this thesis, the images of cross sections of femora, tibiae and humeri obtained by CT-scan were analyzed to determine the locomotion of the Dikika child, a juvenile Au. afarensis, based on comparisons of humans and African apes. The results indicate that the Dikika child's femur shows signs of bipedalism, although the tibia does not. Despite the fact that the shape of the humerus is very similar to that of great African apes, its bending and torsional strength suggest that the Dikika's child did not practice locomotion typical of great apes such as arboricolism or terrestrial quadrupedism. Nevertheless, some results show that bone morphology also depends on the ontogenetic processes and the genetics of each taxon.

Components of turbines, combustion chambers, multi-layered electronic packaging structures and nuclear reactors are subjected to transient thermal loads during their service life. In the presence of a discontinuity like crack or dislocation, the thermal load creates high temperature gradient, which in turn causes the stress intensification at the crack tips. If proper attention is not paid in the design and maintenance of components on this high stress in the vicinity of crack tips, it may lead to instability in the system and decrease in the service life. The concepts of thermal fracture mechanics and its major parameter called transient thermal stress intensity factors can greatly help in the assessment of stability and residual life prediction of such structures. The evaluation of thermal stress intensity factors becomes computationally difficult when the body constitutes of two different materials or is non-homogenous or made of composites. Fracture at bi-material interface is different from its homogenous counterpart because of mixed mode stress condition that prevails at the crack tip even when the geometry is symmetric and loading unidirectional. Because of this, the mode 1 and mode 2 stress intensity factors can not be decoupled to represent tension and shear stress fields as can be done in the case of homogeneous materials. Mathematically, the stress intensity factors at bi-material interfaces are complex due to oscillatory singularity that exists at the crack tip. Although plenty of literature is available for bi-material systems subjected to mechanical loads, very little information is available on problems related to thermal loads. Besides, problems related to transient thermal loads need special attention, since no thermal weight functions are available and the existing methods are computationally expensive. Therefore, the present investigation has been undertaken to develop computational and analytical approaches for obtaining the Mode 1 and Mode 2 stress intensity factors for bi-material interface crack problems using conservation of energy principle in conjunction with the weight function approach for various kinds of thermal loads. In the beginning of the studies, a method to extract the Mode 1 and Mode 2 stress intensity factors for bi-material interface crack subjected to mechanical load is proposed using the concept of Jk integrals. This is extended to thermal loads using J2 line integral and J2 domain integral. Furthermore, weight functions are analytically derived for thermal bi-material stress intensity factors and a computational scheme is developed. These methods are validated for several benchmark problems with known solutions.