Characterization of composite materials, such as Asphalt Concrete (AC) and other engineering materials is required to provide data for design and construction. This is usually carried out through various performance tests, which are always time consuming for specimen preparation, equipment calibration and test setting up. For materials with time- and temperature-dependent properties, this procedure requires fabrication of a large number of specimens in order to get reasonably comprehensive results. Furthermore, for materials that consist of phases with significant differences in properties, macroscopic homogeneous assumption or microscopic statistic approximation will lead to complex correction schemes. This will add complexity in material characterization. On the other hand, the homogeneity based interpretation of test results makes it difficult to understand the interaction between different components. The objective of this research is to develop a numerical testing method for material characterization based on x-ray tomography and finite element method. The introduction of tomography technology, such as x-ray tomography into engineering field makes it possible to obtain material microstructure without disturbing the phase configuration. Along with the development of image analysis technology, image data can be manipulated to obtain digitalized sample reconstruction and to build finite element geometric model. Based on well developed material models that sufficiently capture the essential behavior of individual material component, we developed a framework of numerical tests for characterization of composite material. The geometric model imports the microstructural data of the sample, the configuration of aggregates, voids and flakes, through x-ray tomography and image processing. The voids distribution as well as density variation was quantified to verify the model microscopic characteristics. FORTRAN programs were developed to automatically achieve data transfer and model generation, e.g. boundary identification and ABAQUS simulation model generation. Material model was studied and selected for different material components. Viscoplastic material models were evaluated and calibrated in ABAQUS. Monotonic loading and repeated loading were considered in the study to validate the model for most characterization needs. The digital model was validated through small sample tests and was implemented and used in various material characterizations. For the wood panel characterization, the anisotropic elastic properties were studied while the viscous and plastic responses were studied for asphalt concrete. Factors affecting the accuracy and the limitations of the application were determined. It is worth noting that further advance and data collection will make the calibration of material model more accurate. Nevertheless, the work can be extended to other regimes, such as high speed impact especially where the actual testing is complicated to setup. / Ph. D.

Made available in DSpace on 2016-03-22T17:26:09Z (GMT). No. of bitstreams: 1 Daniela_Martin.pdf: 1349980 bytes, checksum: 0af40cf90affae72c9cc98461fd4ffc3 (MD5) Previous issue date: 2008-11-11 / Objective: comparing muscle strength scores between groups 1 and 2 with questionnaire and clinical anamnesis findings, and describing biofeedback values found. Methods: transversal clinical trial with 70 women with urinary incontinency, divided in 2 groups according to muscle strength, being 40 women in the first group and 30 in the second. All women with previous diagnosis of effort urinary incontinency, in the climacteric period. Patients with neurological problems and pregnant women were excluded. The participants were subjected to the bi-digital test (according to Ortiz, 1996) and biofeedback measures for phasic contraction fibers, as well as a life quality questionnaire KHQ (King´s Health Questionaire) and clinical anamnesis. Data found were described as frequencies, means and standard deviations, minimum and maximum median scores. Results: a higher frequency of women presenting lowered muscle strength was found, for 57.1% (40 women). The most frequent complaints of urinary loss occurred during coughing and sneezing for both groups examined, group 1 (92.5%) and group 2 (96.7%). In group 2, only 1 woman reported total urinary loss. All biofeedback measures were higher in group 1, relative to group 2. In the questionnaire (KHQ), higher domain-specific scores were found in patients with more muscle strength (group 1), resulting in lower quality of life. Conclusion: the assessment of muscle strength is crucial for any physiotherapeutic intervention, as most patients may be altered. More than this, the quality of life must be analyzed, because the same could not be releated with objective datas like: age, urinary time loosing and delivery numbers / Objetivo: comparar os valores obtidos de força muscular do assoalho pélvico em mulheres com incontinência urinária de esforço, entre os grupos de força muscular 1 (menor força) e 2 (maior força), com os resultados do questionário de qualidade de vida e anamnese, bem como, descrever os valores de ativação pressórica atingidos através do biofeedback. Métodos: estudo transversal com 70 mulheres com incontinência urinária, divididas em 2 grupos, de acordo com a força muscular obtida, 40 mulheres no grupo 1 (menor força) e 30 no grupo 2 (maior força). Todas as mulheres com diagnóstico prévio de incontinência urinária de esforço, no período do climatério. Foram excluídas pacientes com problemas neurológicos e grávidas. As pacientes foram submetidas ao teste bidigital (de acordo com Ortiz, 1996) e, medidas de ativação pressórica para fibras de contração fásicas, além da aplicação do questionário de qualidade de vida KHQ e anamnese. Os dados obtidos foram descritos em freqüências, médias e desvios padrões, medianas, mínimos e máximos. Resultados: ocorreu maior freqüência de mulheres que apresentaram força muscular diminuída, 57,1% (40 mulheres). As queixas mais freqüentes de perda urinária deram-se na tosse e no espirro em ambos os grupos analisados, grupo 1 (92,5%) e grupo 2 (96,7%). No grupo 2 (maior força), somente 1 mulher relatou perda urinária completa. Todas as medidas de ativação pressórica foram superiores no grupo 1 (menor força), em relação ao grupo 2 (maior força). No questionário KHQ foram evidenciados maiores escores dos domínios, nas pacientes com maior força muscular (grupo 2), resultando em pior percepção individual da qualidade de vida. Conclusão: para uma intervenção fisioterapêutica objetiva, a avaliação da força muscular do assoalho pélvico torna-se primordial, já que, na maioria das pacientes, esta pode estar alterada. Além disso, a qualidade de vida deve ser analisada, pois a mesma pode não estar 42 relacionada com dados objetivos como: idade, número de partos e tempo de perda urinária por exemplo

Methods for Extending High-Performance Automated Test Equipment (ATE) using Multi-Gigahertz FPGA Technologies Ashraf M. Majid 264 Pages Directed by Dr. David Keezer This thesis presents methods for developing multi-function, multi-GHz, FPGAbased test modules designed to enhance the performance capabilities of automated test equipment (ATE). The methods are used to develop a design approach that utilizes a test module structure in two blocks. A core logic block is designed using a multi-GHz FPGA that provides control functions. Another block called the â application specificâ logic block includes components required for specific test functions. Six test functions are demonstrated in this research: high-speed signal multiplexing, loopback testing, jitter injection, amplitude adjustment, and timing adjustment. Furthermore, the test module is designed to be compatible with existing ATE infrastructure, thus retaining full ATE capabilities for standard tests. Experimental results produced by this research provide evidence that the methods are sufficiently capable of enhancing the multi-GHz testing capabilities of ATE and are extendable into future ATE development. The modular approach employed by the methods in this thesis allow for flexibility and future upgradability to even higher frequencies. Therefore the contributions made in this thesis have the potential to be used into the foreseeable future for enhancements to semiconductor test capabilities.