With the enhancement of the Radio signal communication systems, Wi-Fi technology become a &ldquo / de facto&rdquo / standard used in Campus areas such as hospitals and universities. Besides being used as a data communication method, Received Signal Strength Indicator (RSSI) is also used as a location tracking method. There are lots of studies enhancing the RSSI based location tracking. In this thesis we tried to generate a test environment as close to a real Wi-Fi network scenario as possible. Our aim is to implement a simple moving client among different wireless local area networks, which is tracked across the internet by a stationary client. We also assumed that there is a Network Address Translation (NAT) at both LAN internet edges.

Due to their practical application, flat-plates have been commonly used slab type in constructions in recent years. According to the investigations that were performed since the beginning of the 20th century, the vicinity of the slab-column connection is found to be susceptible to punching failure that causes serious unrepairable damage leading to the collapse of the structures. The objective of this study is to enhance the punching shear strength of slab-column connections in existing deficient flat plate structures. For this purpose, an economical and easy to install strengthening method was applied to &frac34 / scale flat-slab test specimens. The proposed strengthening scheme employs the use of in house-fabricated Carbon Fiber Reinforced Polymer (CFRP) dowels placed around the column stubs in different numbers and arrangements as vertical shear reinforcement. In addition, the effect of column aspect ratio on strengthening method was also investigated in the scope of this study. Strength increase of at least 30% was obtained for the CFRP retrofitted specimens compared to the companion reference specimen. Three-dimensional finite element analyses of test specimens were conducted by using the general purpose finite element analyses program. 3-D finite element models are successful in providing reasonable estimates of load-deformation behavior and strains. The experimental punching shear capacities and observed failure modes of the specimens were compared with the estimations of strength and failure modes given by punching shear strength provisions of ACI 318-08, Eurocode-2, BS8110-97 and TS500. Necessary modifications were proposed for the existing provisions of punching shear capacity in order to design CFRP upgrading.

Neste trabalho, são estudas as verificações da punção global segundo a revisão da NBR 6118. A partir da análise dos fenômenos físicos e com base nos estudos teóricos realizados, são feitas sugestões para serem contornadas algumas omissões da Norma. Também são propostas complementação que facilitem o entendimento das novas recomendações e, ainda, modificações que melhorem seus resultados. Sugerem-se métodos simplificados relacionados à punção excêntrica, e propõem-se algumas alterações quanto ao uso do &#947z como coeficiente majorador na avaliação da estabilidade global. Observa-se que as verificações, apesar de mais trabalhosas, apresentam melhorias significativas em relação à NBR 6118 (1978), mostrando-se mais detalhadas e eficientes. Ainda assim, considera-se importante a introdução de algumas complementações, como aquelas sugeridas neste trabalho. / This work presents an overview of the requirements for punching shear and global stability of buildings in the draft Brazilian Code for concrete structures. Suggestions are made for fulfilling some omissions of the Code, based on theoretical studies and physical phenomena analysis. Some complements and changes are also proposed to facilitate the understanding of the new recommendations and to improve their results. Simplified methods related to the eccentric punching and modifications in the use of &#947z as a first order effects magnifier are suggested. It is concluded that the new provisions are more detailed and efficient, presenting significant improvements on both topics, especially when compared to NBR 6118 (1978). Nevertheless, it is considered important the introduction of some complements, as those suggested in this work.

Made available in DSpace on 2014-07-29T15:03:34Z (GMT). No. of bitstreams: 1 Dissertacao Diorgenes C de Oliveira.pdf: 4985818 bytes, checksum: 3bb65a23267322ba684300f2b7486ab1 (MD5) Previous issue date: 2011-06-17 / The structural behavior and the ultimate punching shear resistance of internal reinforced concrete flat slab-column connections, with one hole adjacent to the column, with or without flexural moment transfer of the slab to the column was investigated. Main variables were: the existence whether or not hole, flexural reinforcement layout and ratio, the direction and sense of the moment transferred and the eccentricity of the load (M (moment transferred to column) / V (shear)) ratio at the connection - 0,50 m or 0,25 m. Seven internal slab-column joining were tested and ultimate loads, cracking, deflections, concrete and reinforcement strains were analyzed. The existence of hole adjacent to the smaller column dimension, the hole dimension, flexural reinforcement rate and placing, the variation of relation Mu/Vu in function of the load, and, than, of eccentricity of the load, influenced the slabs behavior and rupture load. These influences were quantified. Test results were compared with the estimations from CEB-FIP/MC1990, EC2/2004, ACI-318:2005 and NBR 6118:2003. ACI and EC2 presented most conservative estimates, although have presented some non conservative estimates. Brazilian NBR, even though being partly based in EC2, presented smaller conservative estimates and more non conservative estimates. A modification on all codes is proposed for taking in account the moment caused by the eccentricity at the critical perimeter for slabs with holes. / São investigados o comportamento estrutural e a resistência última à punção de ligações laje-pilar de regiões internas das lajes lisas, com um furo adjacente ao pilar, e com ou sem transferência de momento fletor da laje ao pilar. As principais variáveis foram: a existência ou não de furo, a taxa e a distribuição da armadura de flexão, a direção e o sentido do momento transferido e a excentricidade de carga (relação M(momento transferido ao pilar)/V(força cortante)) na ligação, igual a 0,50 m ou 0,25 m. Foram ensaiadas 7 (sete) ligações internas laje-pilar e analisados os resultados das cargas últimas, fissuração, deslocamento vertical, deformações das armaduras de flexão e do concreto. A existência de furo adjacente ao menor lado do pilar, a taxa e a distribuição da armadura de flexão, a variação da relação Mu/Vu em função do carregamento, e, por conseguinte, da excentricidade, influenciaram o comportamento e a carga de ruptura das lajes. Essas influências foram quantificadas. Os resultados experimentais foram comparados com os estimados pelas normas: CEB-FIP/MC1990, EC2/2004, ACI-318:2005 e NBR 6118:2003. O ACI e o EC2 apresentaram estimativas mais conservadoras, embora tenham apresentado algumas estimativas contra a segurança. A NBR 6118:2003, apesar de baseada em parte no EC2, apresentou estimativas menos conservadoras e com um número maior de estimativas contra a segurança. Recomenda-se que todas as normas passem a considerar o momento causado pela excentricidade do perímetro crítico em lajes com furos e, neste sentido, foram apresentadas propostas de modificações para todas as normas estudadas.

Um dos principais problemas das lajes-cogumelo refere-se à ruína por puncionamento da ligação laje-pilar. Esta forma de ruína deve ser evitada, proporcionando-se às lajes as melhores condições para o desenvolvimento de mecanismos de escoamento das armaduras e de ruína por flexão, antes da ocorrência da ruína por cisalhamento. A introdução de fibras de aço em elementos de concreto submetidos a solicitações tangenciais proporciona melhoria de desempenho, seja pelo aumento da capacidade resistente, seja pela alteração da forma de ruína. Pretende-se contribuir com o avanço do conhecimento sobre o assunto, explorando aspectos como a análise das similaridades dos efeitos da adição de fibras de aço na resistência e na ductilidade de lajes-cogumelo à punção, com aqueles que se observam no cisalhamento de vigas prismáticas análogas. Abordam-se os casos de ligações laje-pilar interno sem armadura de punção, variando-se a resistência do concreto, a taxa e o tipo de fibra utilizado. A partir dos resultados experimentais, verificou-se que existe uma similaridade de comportamento estrutural entre esses dois elementos e concluiu-se que é possível utilizar ensaios de cisalhamento em vigas prismáticas para se obter indicadores a serem utilizados nos ensaios de punção de lajes. Foi efetuada uma análise da adaptabilidade de modelos teóricos existentes sobre cisalhamento em vigas e punção em lajes, com vistas à consideração do efeito da adição de fibras de aço ao concreto. Com base nesses modelos, foram estabelecidos critérios quantitativos para avaliação da resistência e da ductilidade das ligações laje-pilar. / One of the main problems of flat slabs concerns the punching shear failure of the slab-column connection. This form of failure must be avoided, providing flat slabs with the best conditions for the development of yielding mechanisms of the flexural reinforcement before the occurrence of shear failure. The addition of steel fibers to concrete elements subjected to tangential stress provides performance improvement, by either the resistant capacity increase or the failure mode alteration. It is intended to contribute to the advance of the subject knowledge, by exploring aspects as the analysis of similarities of the steel fiber addition effects on both strength and ductility of flat slabs to punching shear with those observed in the shear of analogous prismatic beams. The cases approached include internal slab-column connections without shear reinforcement, and the variables investigated included concrete strength, fiber volume and type of steel fiber. From the experimental results, it was possible to verify that there exists a similarity of structural behavior between these two elements and the shear tests in prismatic beams can be used to get indicators to be utilized in punching shear tests of flat slabs. An adaptability analysis of the existing theoretical models on shear in beams and punching shear in flat slabs was carried out in order to consider the steel fibers addition effect on the concrete. Based on these models, quantitative criteria for the evaluation of both strength and ductility of the slab-column connections were established.

Este trabalho descreve uma pesquisa experimental de lajes cogumelo de concreto armado com armadura de cisalhamento, sem envolver a armadura de flexão. Onze lajes cogumelo quadradas de concreto com 200 mm de espessura e 3000 mm de lado, com uma área central carregada de 200 mm de lado, foram testadas até a ruptura. O principal objetivo dos ensaios foi investigar a eficiência de se utilizar esse tipo de armadura de cisalhamento sem envolver a armadura de flexão. Todas as lajes romperam por punção, com cargas de ruptura superiores em até 110%, em relação às cargas de ruptura em lajes similares sem armadura de cisalhamento, demostrando a eficiência da armadura. Foram realizadas também simulações numéricas utilizando modelos axissimétricos e tridimensionais, de lajes cogumelo de concreto armado, com o objetivo de reproduzir numericamente alguns resultados obtidos por pesquisadores e documentados na literatura, validando a parte experimental e a modelagem numérica. As simulações numéricas nãolineares foram realizadas com programa DIANA, e o modelo de fissuração do concreto adotado foi o distribuído (smeared crack). Foram analisados os resultados de cargas últimas e tipos de ruptura, fissuração, deformações nas armaduras e no concreto e as curvas carga x deslocamento. / This work reports experimental research of reinforced concrete flat slabs with use of shear reinforcement not embracing the flexural reinforcement. Eleven square reinforced concrete flat slabs with 200 mm thickness and 3000 mm side lengths, with a square central column of 200mm of side, were tested up to failure. The main objective was to investigate the efficiency of using the mentioned shear reinforcement. All slabs failed by punching and the ultimate loads were superior in up to 110% in relation to slabs without shear reinforcement, demonstrating the efficiency of the reinforcement. The numerical simulations using axisymmetric and three dimensional analyses, of reinforced concrete flats slabs, were carried out with the objective of reproducing some experimental results reported by different investigators, validating the experimental part and also the numerical modelling . The numerical simulations were performed with the software package DIANA, adopting the smeared crack approach to reproduce the concrete behaviour under shear and tension. The evaluated results were mode of failure, strain in steel and loaddeflections curves.

The master’s thesis deals with proposal of technological process for production of computer case in EMKO Case a.s. Computer case is manufactured from a DX51D + Z275 steel sheet with thickness 1 mm. For manufacturing were chosen technology punching and press-brake bending as the best technologies. Master’s thesis contains literary studies of these chosen technologies. Based on literary studies were made technological calculations, proposal of technological process and choice of machines. For punching was chosen machine TRUMPF TruPunch 2000, for press-brake bending hydraulic machine TRUMPF TrumaBend 50V. For chosen solution is made technical and economical evaluation.

JEŽ Marek: Technology of thrust bearing steel cages production . Diploma assert of daily magisteral´s studies, study programme – Industry. The branch manufactoring technology, 2 end form, level 2 – summer semester, study group 50 / 51, academical year 2007 / 2008. FSI of Brno University of Technology, department of forming and plastics, May 2008, 78 pages, 54 pictures, 6 supplements. The main theme of the Diploma Theses is the technology of production of tin cages for axial spherical-roller bearings. The given matter includes the production of tin cages for axial spherical-roller bearings – by traction, cutting, punching and calibration. For the chosen representative, i.e. bearing with marking 29 336 M I suggest the substitution of tin cage instead of the brass one. The component (cage) is made of the sheet iron 11 300 of 4 mm thickness, the basic semi product is the sheet panel with the size of 360 x 4 x 3000 mm. In solving the given matter, it is started from the fact that the current state of the cage is still under development. The aim of the Diploma Thesis is to choose the representative, suggest the appropriate technological progress, proposing the engineering design of functional parts of the tool for punching the holes/windows including the necessary calculations and workshop graphical documentation.

The holder of outdoor air-conditioning units are made out of steel 11 321.21 with 2mm thickness. The production quantity is 2000 units / year. The holder is produced using CNC machine for cutting and bending on CNC press brake. The semi-finished product is a metal sheet (2 x 2000 x 1000 mm). Part of this diploma thesis is to design of the population with the punching tools, the layout of parts on the metal sheet and design of appropriate press brake punches and dies. The conclusion contains economic evaluation of the proposed solution.

An innovative strengthening technique is applied for the first time in this study to provide flexural strengthening in two-way reinforced concrete (RC) slabs supported on edge beams. The technique comprises external bonding of textiles on the tension face of RC slabs through the use of polymer-modified cement- based mortars. The textiles used in the experimental campaign comprised fabric meshes made of long stitch-bonded fibre rovings in two orthogonal directions. The specimens measured 2 x 2 m in plan and were supported on hinges at the corners. Three RC slabs strengthened by textile reinforced mortar (TRM) overlays and one control specimen were tested to failure. One specimen received one layer of carbon fibre textile, another one received two, whereas the third specimen was strengthened with three layers of glass fibre textile having the same axial rigidity (in both directions) with the single-layered carbon fibre textile. All specimens failed due to flexural punching. The load-carrying capacity of the strengthened slabs was increased by 26%, 53%, and 20% over that of the control specimen for slabs with one (carbon), two (carbon) and three (glass) textile layers, respectively. The strengthened slabs showed an increase in stiffness and energy absorption. The experimental results are compared with theoretical predictions based on existing models specifically developed for two-way slabs and the performance of the latter is evaluated. Based on the findings of this work the authors conclude that TRM overlays comprise a very promising solution for the strengthening of two-way RC slabs.