Os erros cíclicos nas escalas das máquinas de medir a três coordenadas (MM3Cs) exercem influência significativa nos resultados das medições efetuadas em comprimentos pequenos. Um dos fatores que contribuem para a ocorrência dos erros cíclicos é a acuracidade limitada dos métodos utilizados na fabricação de escalas. As MM3Cs utilizam escalas desenhadas e fabricadas por métodos fotográficos ou riscadas em máquinas tipo \"step and repeat\". Ambos os métodos produzem um erro sistemático entre traços sucessivos. Desta forma, a medida que o número de traços aumenta as parcelas do erro sistemático somam-se e quando atingem um determinado valor este erro é compensado. Esta correção é feita a cada distância cujo valor corresponde ao de um período cíclico de baixa freqüência e o processo repete-se até que toda a escala seja riscada. Outro fator que contribui para a existência dos erros cíclicos origina-se da resolução exigida pela MM3C, que é sempre bastante alta e ultrapassa as capacidades existentes atualmente para fabricação de escalas. O que se faz para lidar com o problema da resolução é subdividir eletronicamente o espaço entre traços consecutivos da escala. Esta divisão eletrônica está associada a um sinal seno gerado pelas franjas de Moiré. A digitalização e subdivisão deste sinal geram erros periódicos, também conhecidos como erros cíclicos de alta freqüência. Embora diversos erros das MM3Cs tenham sido largamente estudados, ainda hoje, não foi realizada uma observação sistemática para que se tenha a exata medida da influência dos erros cíclicos, na medição a três coordenadas. Para suprir essa necessidade e contribuir na busca de novos métodos de avaliação, este trabalho apresenta os procedimentos de medição dos erros cíclicos de baixa e de alta freqüência, bem como a aplicação de Análise de Fourier aos conjuntos de dados obtidos. A medição da distância entre as linhas consecutivas da régua móvel da MM3C também foi realizada e os resultados comprovaram a existência dos erros de fabricação, a ocorrência de compensação periódica e também sugeriram os erros de subdivisão eletrônica. Além disso, no levantamento dos erros cíclicos de baixa freqüência foi confirmada a existência de um período cíclico de quatro milímetros. / Cyclic errors in scales of Coordinate Measuring Machines (CMMs) have a significant influence in measuring results on a very small displacement hindering most of the measuring tasks. One of the factors that contribute to the appearance of the cyclic errors is the limited accuracy of the used manufacturing methods of the scales. CMMs use scales drawn and manufactured by photographic methods or marked in step and repeat machines. In both methods the distances between succeeding lines are prone to systematic errors and therefore, with the increasing of the number of lines systematic errors are added up. Error compensation is provided when the amount of errors reaches a predetermined value. The error correction made at predetermined lengths defines a period what one can call the low frequency cyclic error. This process must be repeated all along the scale. Another factor that contributes to the existence of cyclic errors originates from high resolution required by CMM that goes beyond the existent manufacturing capacities of scales. This problem is somewhat solved by means of an electronic signals splitting up. The electronic sign obtained as two consecutive lines on the scale is probed can be associated to a sine signal what is generated by Moiré type fringes. Digital conversion and electronic division of these signals also generate periodic errors and can be called high frequency cyclic error. Although several types of errors in CMMs have been largely studied,there is a lack regarding the cyclic errors. A huge need for a systematic study and observation of these errors is needed to permit an exact measure of its influence on coordinate measurements. To cope with the urgent need and to contribute in the search for new evaluation methods of the cyclic errors, this work presents a measuring procedure of low and high frequency cyclic errors and the application of Fourier Analysis to the testing data. Measurements of distances between consecutive lines of the scale were also obtained and the results have shown the existent manufacturing errors and suggested frequencies and period of errors of electronic division. A cyclic period of four millimeters was confirmed in the low frequency tests.

Bien que les propriétés de l'antimatière soit largement testées dans le secteur faible, fort et électromagnétique, la question de la gravitation pour ces objets reste ouverte. En observant la chute libre d'atomes d'anti-hydrogène, l'expérience AEGIS prévoit de mesurer pour lapremière fois l'accéleration gravitationelle pour l'antimatière. Le dispositif prévu pour cette mesure se compose de trois réseaux en transmission et d'un détecteur possèdant une haute résolution spatiale. Le travail de cette thèse se concentre sur la caractérisation d'un tel dispositif avec une source d'ions de basse énergie, permettant de mesurer simultanément les champs électriques et magnétiques environnant. La sensibilité atteinte en font un dispositif compétitif avec les meilleurs appareils disponibles. Une attention particulière est également portée sur l'implémentation de l'expérience avec des réseaux de pas plus fin, afin de mettre en évidence l'interférence quantique des ions. Les effets qui pourraient réduire le contraste des franges d'interférences sont passés en revue et discutés. Enfin, la réalisation d'une ligne de faisceau capable de sélectionner des particules de basse énergie et l'intégration d'un détecteur silicium dédié à la détection d'antiprotons est détaillée dans le but de réaliser pour la première fois l'interférence de particules d'antimatière / Although numerous experiments investigate the properties of antimatter in the weak, strong and electromagnetic sector, the gravitational interaction for these objects remains an open question. By observing the free-fall of antihydrogen atoms, the AEGIS experiment plans toperform the first measurement of the gravitational acceleration on antimatter. The device envisioned for such an experiment consists in a set of three transmission gratings with a pitch of few micrometers, associated with a high resolution imaging detector. This thesis focuses on testing such a device with a low-energy ion beam, enabling one to measure simultaneously the magnitude of surrounding electric and magnetic fields. The sensitivity achieved makes such an apparatus competitive with state-of-the-art fieldmeters. An effort is moreover initiated to perform the same experiment with smaller grating periodicities since it could reveal the quantum interference of the ions. In order to probe the quantum behavior of protons, the effects which might destroy the interference pattern are reviewed and discussed. We finally detail the implementation of a velocity selector and a silicon detector dedicated to low energy antiprotons. These two components are indeed a prerequisite to perform for the first time theinterference of antimatter particles

Orientadores: Mauro Augusto Demarzo, Inácio Maria Dal Fabbro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-18T17:31:36Z (GMT). No. of bitstreams: 1 Affonso_EudirAlves_D.pdf: 5364894 bytes, checksum: 5129a906f83a74c648da3835cf634275 (MD5) Previous issue date: 2011 / Resumo: A análise do comportamento das estruturas das obras de engenharia civil passam pela determinação das deformações e tensões atuantes em seus elementos. Neste contexto, a extensometria desempenha um papel fundamental. Nos laboratórios de estruturas civis do Brasil, os extensômetros utilizados, em geral, têm se limitado a determinar a deformação específica em um dado ponto dos corpos-de-prova. Verifica-se, porém, que a extensometria óptica apresenta-se como alternativa vantajosa para esta tarefa, fornecendo resultados para todos os pontos da área de medição (em campo inteiro ou full field). Entre as técnicas da extensometria óptica, a de moiré foi escolhida por ser a mais simples e apresentar os menores índices relativos de ruídos. O objetivo geral desta tese foi a implantação desta técnica. Os resultados mostraram que a sensibilidade da técnica de moiré por interferência mecânica (ou geométrica) alcançou níveis que anteriormente só podiam ser obtidos com o uso de interferômetros (moiré interferométrico). Esta tarefa foi possível por multiplicação de franjas obtida por processo digital (DFM), e mostrou-se capaz de medir deformações micrométricas a partir de retículos de baixa frequência. Este trabalho é apresentado como técnica de moiré geométrico digital (TMGD), pois tudo, desde a captura da imagem do retículo do modelo até a geração de franjas foi feita por meio digital, e não se insere na classificação geral das técnicas de moiré presente na bibliografia. O resultado obtido foi algo ainda inovador: uma técnica de baixo custo, insensível a perturbações do meio-ambiente, e capaz de fazer medições na superfície plana dos diversos materiais estruturais, sem aparatos dispendiosos. As conclusões mostram a aplicabilidade do método proposto para medir deformações e analisar tensões em modelos e estruturas de engenharia civil / Abstract: The study of the behavior of building structures pass through the determination of the strain and stresses to evaluate the level of local and global security against the active actions. In the last years in Brazil, the extensometers have been commonly used to measure the strain at a specific single point. The optical extensometry presents itself as an alternative to this task by providing results for all points of measurement area (full field). The moiré techniques are the simplest of the optical extensometry and have the smaller indeces relating to noise. In this work, the sensitivity of mechanics (or geometric) interference of moiré technique reached levels that previously could only be obtained using interferometers (moiré interferometry). It is worth noting that interferometers are appliances that cost thousands of dollars. This task was made possible through the multiplication of fringes obtained through digital technology with application present in photography and digital image processing and proved able to measure deformations for micrometric from very low frequency cross gratings. This work is presented as digital geometric moiré technique (TMGD) because everything from image capture of specimen gratings until the generation of fringes was made by digital means and therefore does not fall within the classification set out in chapter which deals with the classification of moiré techniques. The result was something still unheard in civil engineering in Brazil, a low-cost technique, insensitive to vibrations and of the environment, moreover able to make measurements in plane surfaces without major apparatus. Findings show the applicability of the proposed method to measure strain and to analyze stresses in models and civil engineering structures / Doutorado / Estruturas / Doutor em Engenharia Civil

Thesis (MSc)--Stellenbosch University, 2015. / English abstract: We introduce a method for determining the position of a camera with accuracy beyond that which is obtainable through conventional methods, using a single image of a specially constructed calibration object. This is achieved by analysing the moiré pattern that emerges when two high spatial frequency patterns are superimposed, such that one pattern on a plane is observed through another pattern on a second, semi-transparent parallel plane, with the geometry of both the patterns and the planes known. Such an object can be created by suspending printed glass over printed paper or by suspending printed glass over a high resolution video display such as an OLED display or LCD. We show how the camera’s coordinate along the axis perpendicular to the planes can be estimated directly from frequency analysis of the moiré pattern relative to a set of guide points in one of the planes. This method does not require any prior camera knowledge. We further show how the choice of the patterns allows, within limits, arbitrary accuracy of this coordinate estimate at the cost of a stricter limit on the span along that coordinate for which the technique is usable. This improved accuracy is illustrated in simulation. With a sufficiently accurate estimate of the camera’s full set of 3D coordinates, obtained by conventional methods, we show how phase analysis of the moiré pattern in relation to the guides allows calculation of a new estimate of position in the two axes parallel to the planes. This new estimate is shown in simulation to offer significant improvement in accuracy. / Afrikaanse opsoming: Ons stel ’n metode bekend om die posisie van ’n kamera te bepaal met akkuuraatheid bo dit wat verkrygbaar is uit konvensionele metodes, deur gebruik te maak van ’n spesiaal gekonstrueerde kalibrasievoorwerp. Die metode berus op analise van moiré patrone wat onstaan waneer twee hoë ruimtelike frekwensie patrone oor mekaar neergelê word deurdat een patroon op ’n plat vlak waargeneem word deur ’n tweede patroon op ’n parallelle, gedeeltelik deursigtige vlak, met die geometrie van beide patrone en vlakke bekend. So ’n voorwerp kan geskep word deur ’n spesiaal gedrukte glas vlak te monteer oor gedrukte papier of oor ’n hoë resolusie skerm, soos ’n OLED skermof LCD. Onswys hoe die kamera se koördinaat langs die as loodreg op die vlakke direk uit frekwensie analise van die moiré patroon relatief tot ’n stel gidspunte in een van die vlakke bepaal kan word. Hierdie metode vereis geen vooraf kennis oor die kamera nie. Ons wys verder hoe die keuse van patrone, binne perke, arbitrêre akkuuraatheid in die bepaling van hierdie koördinaat kan verkry ten koste van ’n nouer bruikbare verstek in hierdie koördinaat. Die verbeterde akkuuraatheid is geïllustreer in simulasie. Indien ’n benadering van die kamera se volle stel 3D koördinate met voldoende akkuuraatheid ook beskikbaar is, wys ons ook hoe fase analise van die moiré patroon relatief tot die gidspunte ons in staat stel om’n nuwe benadering te kanmaak vir die koördinate in die twee asse parallel aan die vlakke. Daar word in simulasie getoon hoe hierdie nuwe benadering beduidend beter akkuuraatheid kan bied in vergelyking met konvensionele metodes van benadering.

As technology progresses towards smaller electronic packages, thermo-mechanical considerations pose a challenge to package designers. One area of difficulty is the ability to predict the fatigue life of the solder connections. To do this one must be able to accurately model the thermo-mechanical performance of the electronic package. As the solder ball size decreases, it becomes difficult to determine the performance of the package with traditional methods such as the use of strain gages. This is due to the fact that strain gages become limited in size and resolution and lack the ability to measure discreet strain fields as the solder ball size decreases. A solution to the limitations exhibited in strain gages is the use of Moiré interferometry. Moiré interferometry utilizes optical interferometry to measure small, in-plane relative displacements and strains with high sensitivity. Moiré interferometry is a full field technique over the application area, whereas a strain gage gives an average strain for the area encompassed by the gage. This ability to measure full field strains is useful in the analysis of electronic package interconnections; especially when used to measure strains in the solder ball corners, where failure is known to originate. While the improved resolution of the data yielded by the method of Moiré interferometry results in the ability to develop more accurate models, that is not to say the process is simple and without difficulties of it's own. Moiré interferometry is inherently susceptible to error due to experimental and environmental effects; therefore, it is vital to generate a reliable experimental procedure that provides repeatable results. This was achieved in this study by emulating and modifying established procedures to meet our specific application. The developed procedure includes the preparation of the specimen, the replication and transfer of the grids, the use of the PEMI, interpretation of results, and validation of data by finite element analysis using ANSYS software. The data obtained maintained uniformity to the extent required by the scope of this study, and potential sources of error have been identified and should be the subject of further research.

The objective of this research was to provide means for the experimental analysis of deformations encountered in micromechanics. Whole field contour maps of U and V displacements in a microscopic field of view were desired. Since displacements within a small field can be very small even when strains are large, ultra-high sensitivity is required. The specific objective was displacement sensitivity of 50 nm per fringe contour, which corresponds to that of moire with 20,000 lines per mm, in combination with spatial resolution of the optical microscope (2-5 μm). The objective was achieved by the following developments. First, the basic sensitivity of moire interferometry was increased beyond the previously conceived theoretical limit. This was accomplished by creating the virtual reference grating inside a refractive medium instead of air, thus shortening the wavelength of light. A very compact four beam moire interferometer in a refractive medium was developed for microscopic viewing, which produced a basic sensitivity of 208 nm per fringe order. Its configuration made it inherently stable and relatively insensitive to environmental disturbances. An optical microscope was employed as the image recording system to obtain the desired spatial resolution. Secondly, a fringe multiplication scheme was implemented. Here, an automatic fringe shifting and fringe sharpening scheme was developed, wherein very thin fringe contours of order N* = βN were produced, where N is the fringe order in the basic moire pattern and β is a fringe multiplication factor. A factor of 12 was achieved, providing a sensitivity of 17 nm per fringe contour. This corresponds to moire with 57,600 lines per mm (1,463,000 lines per in.), which exceeds the sensitivity objective. The mechanical and electronic systems implemented here are remarkably robust and quick. The method was demonstrated with three practical applications: interface strains in a thick 0°/90° graphite/epoxy composite, fiber/matrix deformations of metal/matrix composites, and thermal deformation around a solder joint in a microelectronic subassembly. / Ph. D.

Techniques for shear property measurements for composite and isotropic materials were investigated. A new strain gage called the shear gage was conceived, designed, and tested for routine shear characterization on notched shear specimens. The shear gage integrates the shear strain in the entire test section of the losipescu and compact shear specimens. The result was consistent and accurate determination of the shear stress/strain response of materials. Prior knowledge of material properties or shear strain distributions were not required. Deficiencies in the losipescu shear test were automatically compensated when shear gages were placed on the two faces of the specimen. The shear gages were tested on composite and isotropic materials and produced higher accuracy and consistency than could be produced using current technology. Moir© interferometry was used to evaluate the ability of the shear gage to measure the average shear strains. The results from the evaluation program confirmed the attributes of the concept. / Ph. D.

This paper presents the theory and results of three Moire methods 1) the incoherent projection Moire method, 2) the electronic phase detection method, and 3) the fringe multiplication method. It is proposed that these three methods be used together in a system to measure out-of-plane displacements of large diffusely reflecting surfaces. The operation of the system is divided into two processes. The first process records an incoherent moire pattern which contains the out-of-plane displacement information. The second process uses a transduced coherent image of the pattern produced in the first process to optically generate a quantitative result with variable sensitivity. The coherent processing is a technique that uses the fringe multiplication method with the electronic phase-detection method. The result is the quantitative, out-of-plane displacement measurement with sensitivity enhancement that can be altered during coherent processing of the Moire fringe pattern. / Master of Science

Due to the rapid expansion of applications of composite materials, investigations of their properties have greatly increased. Since theoretical and numerical methods have many limitations for anisotropic materials, experimental methods are sometimes the only way to answer the questions. It has been proved that moire interferometry is a powerful technique in the study of composite materials. The high sensitivity and resolution of a measurement technique is the key to determining the properties of a material which has a fine and complicated structure such as fiber reinforced composite laminates. In this paper, a carrier fringe method is introduced to increase the resolution of the fringe gradient in the moire technique. The ability of measurement is extended to the micromechanics region. High strain concentrations and the dramatic displacement variations can be determined by measuring the slopes of carrier fringes. Strain distributions across the plies (with the thickness of 125 μm) in graphite/epoxy composites and strain concentrations in the resin-rich zones (with the thickness of 10 μm) between neighboring plies are revealed by the carrier fringe technique. Three experiments are presented to show the effectiveness of the application of carrier fringes to resolve fringe gradients and obtain strains. The current moire technique is limited to the optical laboratory because it is extremely sensitive to the disturbance of the environment. A vibration with magnitude of 0.2 μm can completely wash out the contrast of a moire fringe pattern. The study has been done in moving moire interferometry off the optical table. Vibration insensitive moire systems are investigated to extend the moire technique to the tests of large structures and using testing machines for loading. Vibration problems are discussed and the new ideas for eliminating vibration effects are presented. Six representative schemes are analyzed and three of these systems are built to perform experiments in rough environments such as on a hydraulic testing machine. The results show the great success of these new systems. / Ph. D.

Shifting Surfaces is an MFA thesis exhibition comprised of screenprints and sculptures. The written thesis contains documentation of the exhibition and a selection of related works, focusing on the progression of research and artmaking which led to the development of a new visual language. Shifting Surfaces employs emergent phenomena and abstraction to evoke the enmeshed relationship between bodies, ecology, and technology. / Master of Fine Arts / Shifting Surfaces is an MFA thesis exhibition comprised of screenprints and sculptures. The written thesis contains documentation of the exhibition and a selection of related works, focusing on the progression of research and artmaking which led to the development of a new visual language. Shifting Surfaces employs emergent phenomena and abstraction to evoke the enmeshed relationship between bodies, ecology, and technology.