Made available in DSpace on 2014-12-17T14:55:55Z (GMT). No. of bitstreams: 1 JoaoCSF_DISSERT.pdf: 4517412 bytes, checksum: 2112619de393ca975c806fa334e083ff (MD5) Previous issue date: 2011-12-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Relevant researches have been growing on electric machine without mancal or bearing and that is generally named bearingless motor or specifically, mancal motor. In this paper it is made an introductory presentation about bearingless motor and its peripherical devices with focus on the design and implementation of sensors and interfaces needed to control rotor radial positioning and rotation of the machine. The signals from the machine are conditioned in analogic inputs of DSP TMS320F2812 and used in the control program. This work has a purpose to elaborate and build a system with sensors and interfaces suitable to the input and output of DSP TMS320F2812 to control a mancal motor, bearing in mind the modularity, simplicity of circuits, low number of power used, good noise imunity and good response frequency over 10 kHz. The system is tested at a modified ordinary induction motor of 3,7 kVA to be used with a bearingless motor with divided coil / Relevantes pesquisas v?m sendo desenvolvidas em m?quinas el?tricas sem mancais mec?nicos ou rolamentos e que s?o, genericamente, denominadas m?quinas sem mancais ou, em car?ter espec?fico, motor mancal. Neste trabalho faz-se uma abordagem introdut?ria sobre as m?quinas sem mancais e apresenta??o de seus dispositivos perif?ricos enfatizado o projeto e implementa??o de sensores e interfaces necess?rios ao controle de posicionamento radial do rotor e rota??o da m?quina. Os sinais oriundos da m?quina s?o condicionados ?s entradas anal?gicas do DSP TMS320F2812 e utilizados no programa de controle. Este trabalho tem por proposta elaborar e implementar um sistema envolvendo sensores e interfaces compat?veis as entradas e sa?das do DSP TMS320F2812, para controle de um motor mancal, tendo como foco a modularidade, simplicidade de circuitos, redu??o das fontes de alimenta??o, melhoria na imunidade a ru?dos e melhor resposta em frequ?ncia acima de 10 kHz. O sistema ? testado em um motor de indu??o de 3,7 kVA modificado para operar como uma m?quina sem mancais com bobinado dividido

Joints in structures always cause strength reduction. The percentage of strength reduction depends upon the selection of several factors such as: type of joint (i.e. adhesive or mechanical), technique of joint (i.e. lap joint, butt joint etc.), geometry of joint, mode of load application etc. Here in this research, the strength of adhesively bonded butt joints with several geometries, later referred as joint angles, is investigated under uniaxial tension loading. Adhesively bonded simple butt joints, where joints are placed perpendicular to the loading direction are in common practice mainly because of ease in manufacturing process. But when the joint is fabricated with an angle respective to the loading direction, the geometry of the joint itself affects the strength of the joint significantly. Without going too deep into other factors that affects the joint strength such as manufacturing techniques, manufacturing defects, material behavior etc. only the geometry of the joint is considered and it is evaluated whether it is worth to change the joint geometry or not. The significant issue in adhesive joint technology is the prediction of joint strength. However, an approach similar to plastic yield criterion later referred as elastic limit offset method (attempted for 0.025% offset) is considered to estimate the linear elastic limit. Since RUAG Space AB (the industry for which this project is performed) is only interested in the linear elastic regime of the stress-strain curve, therefore the elastic limit offset method is considered to be the suitable one. The present work is concerned with the study of adhesively bonded angled butt joint vs. strength behavior. The strength of adhesively bonded butt joints is examined for several butt joint angles under uniaxial tensile loading. The employed butt joint angles are: 0°, 30°, 45°, 60° and 75°. The main objective of the current investigation is to find the joint angle that has the highest strength or the highest capability of load transfer. In addition to the above, the influence of the joint on the stress field, joint strength and type of failure is also evaluated using DSP (Digital Speckle Photography) technique and simulated using well known finite element tool, ABAQUS. It is observed that specific strength of the joint is greatly influenced with joint angle. The 45° joint showed the highest elasticity and failed like ductile behavior whereas 75° joint showed the lowest elasticity and failure was purely brittle. Moreover, post-failure inspection of fractured surfaces showed cohesive failure (failure within adhesive layers) for 0°, 30°, 45° and 60°whereas 75° showed composite or adherend failure. The simulation is performed for each joint angle. However to validate the model only 45° and 75° joints results are compared with experimental results and plotted in the report. The simulation results of these angles showed good agreement with the experimental ones. Moreover, the stress fields for each joint angle are captured (from ABAQUS), showing that all joints are susceptible to inter-laminar shear. Besides, the relative slip between the top and middle adherends is also calculated, the results show that, the 45° joint has higher tendency of relative slip than others.