The basis of this thesis was that Kåver & Mellin Uppsala wanted todetermine if they should train their employees in the software RobotStructural Analysis. The company had licenses for the program that theydid not use due to lack of experience. The purpose of the project wastherefore to examine how Robot is used for designing structures and tocompare its usefulness to its competitor FEM-Design. The comparison ofusefulness was made by designing an identical structure in bothprograms. The focus of the study was to compare three main areas,workflow, areas of use and calculation results. This was made for themost common construction elements that were limited to concrete slabs,concrete walls, steel columns and steel beams.The study proved the programs to be similar. Designing steel profilesis more efficient in Robot. Another advantage of Robot is that there isan official online help page and a useful online forum, that FEM-Designlacks. One significant disadvantage of Robot is that the calculationsfor concrete are made with outdated national standards for Eurocode.The disadvantage was crucial and led to the conclusion that Kåver &Mellin Uppsala should wait for updated standards before using theprogram fully but they could start using Robot for load calculationsand steel design.

A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, September 2016 / The aim of this research was to investigate the bord and pillar design procedure in use at the time on chrome and platinum mines and subject it to a critical appraisal and, if necessary, propose an improved methodology. An analysis of the current method and some of the alternatives proposed in the literature has shown that the methodologies suffer from drawbacks that can be detrimental to the mining industry due to overdesign or rendering an excavation unsafe. The conclusion was that improvement is essential. The influence of the variability of the rock mass properties input parameters on the factor of safety in the current equation was calculated and the findings were that the value of the factor of safety can vary by up to 30 percent due to these variation. The proposed process adopted FLAC2D Hoek-Brown simulations to develop full stress deformation curves for typical pillars. The mine stiffness concept was introduced to determine the pillar load which automatically included the influence of the pillar and strata stiffness, excavation spans, pillar yield and failure. The factor of safety was obtained by dividing the pillar strength by the stress value of the intersection point of the two linear equations for the stiffness of the system and the pillar respectively. The proposed methodology was calibrated by applying it to two mines in the Bushveld. The conclusion was that the methodology is a significant improvement over the one in use. It was shown that a combination of the FLAC2D Hoek Brown and the System Pillar Equilibrium Concept can predict the extent of the fracture zones and, to certain extent, the pillar stresses. The stage has been reached where the methodology can be used to predict the most likely commencement of failure of pillars at greater depth and alternative pillar mining methods can be modelled. / MT2017

A thesis submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 1992. / This thesis presents the results of theoretical and experimental investigations into the behaviour and ultimate load capacity of latticed lower panels with cross-bracing diagonals made of equal-leg, hot-rolled steel angles under the effects of in-plane loads. Loading tests to collapse are carried out on cross-bracings in reduced-scale two-dimensional frames of various arrangements. The Southwell-plot of deflection measurements immediately prior to first yield of the diagonals is used to define equivalent end eccentricities and effective length factors, which therefore account for geometric and material imperfections of the test specimens. A proposal for new design formulae for calculating the resistance of struts is presented. The new design equations are based on the secant formula and are calibrs"ed against the experimental results. A computer model is developed based on flexibility equations which do not require an narative analysis procedure. The non-linear effects are given through the inclusion of Berry stability functions. The effects of eccentric forces and nodal restraints are simulated at all joints in which diagonals and main chords are connected . An additional model is formulated using a mainframe finite-element cod, demonstrating that it is now possible to perform non-linear analyses of complex frames including asymmetric members. Experimental results from this and other investigations are compared with ultimate load predictions based on the new design equations and the computer models and also usual buckling curves for design of steel transmission towers. In all cases the proposed models give acceptable predictions ot the behaviour and ultimate capacity of the bracings. In particular, failure loads calculated with the new design equations show improvements with respect to predictions based on current design buckling curves. These equations, therefore, can be used for design of steel latticed tower structures with angle members.

A primeira parte desta dissertação consiste em uma exposição de alguns aspectos do fenômeno de difração de raios X por cristais, de vários tipos estruturais de zeólitas e de uma introdução ao Método de Rietveld (MR)para refinamento de estrutura utilizando amostras policristalinas. Apresenta-se a seguir o resultado da aplicação do MR a uma amostra conhecida: a alumina Al2O3-&#945 (Corindo). No teste foram refinados o fator de escala, o ponto zero (2θ0), os parâmetros de rede, os parâmetros atômicos posicionais e vibracionais e os parâmetros de perfil usando-se a função pseudo-Voigt. Passa-se então à aplicação do MR ao refinamento da estrutura de uma zeólita Y sinética e de três amostras da mesma zeólita após terem sido tratadas sob ação de vapor d´água e calor com (NH4) 2SO4 e com H2SO4 / The first parto f this dissertation is presented some aspects of X-ray diffraction by crystals, different kind of zeolites and an introduction to the Rietveld Method (RM) of structure refinement by polycrystalline samples. The refinement of &#945- Al2O3 (Corindon) is then presented as a test for the use of RM. In this test the scale factor, the zero point (2θ0), the lattice parameters, the positional, vibrational atomic parameters and the profile parameters were refined using the pseudo-Voigt profile function. Next the RM is used for the structure refinement of a synthetic Y-zeolite and of three samples of the same zeolite after treatment with water vapour, heat, (NH4)2SO4 and H2SO4

Degradation of the Carbon Fiber/Vinylester (CF/VE) polymer matrix composites due to different electrochemical interactions when exposed to seawater or at high temperature had been experimentally investigated. Water uptake behavior of composite specimen was examined based on weight gain measurement. Three point bending test was performed to quantify the mechanical degradation of composite immersed in seawater with different environmental and electrochemical interactions. Finally, Electrochemical Impedance Spectroscopy (EIS) was used to better understanding of the degradation process in CF/VE composite produced by interactions between electrochemical and different environmental conditions. A detailed equivalent circuit analysis by using EIS spectra is also presented in an attempt to elucidate the degradation phenomenon in composites. / by Md Hasnine. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

O estudo trata da análise estrutural dentro da indústria têxtil para mapeamento dos grupos estratégicos. O objetivo foi construir mapas dos grupos estratégicos para análise das vantagens e desvantagens competitivas da indústria têxtil. Este trabalho se constitui de pesquisa bibliográfica referendada em autores que tratam dos temas administração estratégica e competitividade, na edição especial da revista Exame Melhores e Maiores dos anos de 2009, 2010, 2011 e 2012 e nos relatórios setoriais da indústria têxtil brasileira editados pelo Instituto de Estudos e Marketing Industrial (IEMI), a fim de construir um mapa dos grupos estratégicos da indústria têxtil. Os resultados mostraram que o grau de verticalização das empresas têxteis é diretamente proporcional a sua participação de mercado, levando a entender que a estratégia de verticalização é exitosa. / The study deals with the structural analysis inside the textile industry for the mapping of strategical groups. The aim was to build a map of those groups in order to make an analysis of competitive advantages and disadvantages of the textile industry. This work constitutes a bibliographic research refereed on authors that deal with the themes Strategical Administration and Competitiveness, on the special edition of a magazine called Exame Melhores e Maiores the years 2009, 2010, 2011 and 2012 and on sector reports of Brazilian Textile Industry edited by Instituto de Estudos e Marketing Industrial IEMI (Industrial Marketing and Studies Institute), in order to build a map about strategical groups of textile industry. The results indicate that the textiles companies verticalization process is the consequence of their ranking in the market, demonstrating that the verticalization process can be an effective one.

Nos últimos anos, a utilização de pontes estaiadas tem evoluído rapidamente e novos conceitos estruturais têm surgido, como por exemplo: o desenvolvimento de seções flexíveis e esbeltas, o aumento do comprimento dos vãos e a aplicação de pontes estaiadas em múltiplos vãos. Torna-se necessário portanto uma compreensão profunda do comportamento estrutural desse sistema. No processo de projeto as decisões mais importantes são geralmente feitas nas fases iniciais quando a síntese predomina sobre a análise numérica, tornando fundamental o entendimento do comportamento físico da estrutura na fase de pré-dimensionamento. Na concepção de uma ponte estaiada inúmeras alternativas estruturais são possíveis, por exemplo: pode-se utilizar um ou dois planos de cabos em diferentes arranjos, mastros e tabuleiros com seções transversais diversas e diferentes tipos de vinculação externa. Para um dado problema, mais de uma solução pode ser viável, no entanto algumas delas propiciarão a maior eficiência, sob o ponto de vista de consumo de materiais, facilidades construtivas, prazo de execução e comportamento físico da estrutura. Neste trabalho foram analisadas diferentes concepções estruturais com o objetivo de fornecer subsídios para as decisões tomadas no início do projeto estrutural de uma ponte estaiada. Para tanto, a partir do entendimento preliminar do comportamento físico de diferentes sistemas, foram definidas alternativas estruturais para análise estática através de modelos de elementos finitos tridimensionais. A análise e a comparação dos resultados permitiram um aprofundamento daquele entendimento. Além disso, alguns aspectos relevantes no projeto de pontes estaiadas foram estudados, tais como: o pré-dimensionamento dos estais, a definição da força de protensão inicial dos mesmos, o estudo do problema de fadiga nos cabos e a elaboração de modelos simplificados para análise preliminar do comportamento do tabuleiro e da torre. / In the last years, the use of cable-stayed bridges has increased a lot and new design concepts have appeared, such as: the development of slender and flexible deck sections, the increase in span length and the application of cable-stayed bridges in multiple spans. It is thus necessary a thorough understanding of the structural behavior of this system. During the design process the most important decisions are usually taken in the initial phases, when the synthesis prevail over the numerical analysis, which requires the understanding of the physical structural behavior in the preliminary design. The design of cable-stayed bridges involves many structural alternatives, for example: it is possible to use one or more cable planes in different arrangements, a wide range of pylons and decks cross sections and different types of external connections. For a given problem, more than one solution can be feasible, however some of them will provide a greater efficiency, from the point of view of material consumption, construction facilities, time of execution and physical behavior of the structure. This study analyzes different structural conceptions with the purpose of helping in the decisions made in the beginning of a cable-stayed bridge structural project. For this, from the preliminary understanding of the physical behavior of different systems, some structural alternatives were defined and a static analysis using finite element models was carried out. The analysis and comparison of results allowed an improved understanding of the problem. Furthermore, some relevant aspects in cable-stayed bridges were studied, such as: the preliminary stay design, the definition of initial prestressing force in the stays, the study of the fatigue behavior of the cables and the development of simple models to simulate the response of the bridge decks and pylons.

Segundo a legislação brasileira, as estruturas de concreto armado devem ser verificadas em situação de incêndio, de modo a assegurar a capacidade portante para permitir a fuga dos usuários e o combate ao fogo com segurança e minimizar a propagação do incêndio para outros compartimentos. Para estruturas de concreto armado, especial atenção deve ser dada aos pilares. A redução da capacidade portante desses elementos é significativa em situação de incêndio e seu colapso pode resultar na instabilidade global da estrutura em certos casos. O cálculo do tempo de resistência ao fogo de pilares de concreto armado, em fase de projeto, é feito normalmente usando métodos simplificados dados pelas normas técnicas. Esses métodos possuem campos de validade limitados e podem apresentar resultados excessivamente seguros (antieconômicos) e em alguns casos contra a segurança. Neste trabalho foi desenvolvida uma ferramenta computacional para o cálculo do tempo de resistência ao fogo de pilares de concreto armado em situação de incêndio, dados os campos de temperaturas simétricos na seção transversal em função do tempo de exposição ao incêndio-padrão. O cálculo do pilar foi baseado no método da estimativa da curvatura dado pelo Eurocode 2 (EN 1992-1-2:2004). A seção transversal foi discretizada em elementos (concreto e aço), na qual as deformações térmicas e as propriedades termomecânicas de cada elemento foram calculadas de acordo com sua temperatura. O método da estimativa da curvatura permite ainda considerar os efeitos da não linearidade geométrica, que geralmente se tornam importantes devido à redução da rigidez do pilar sob temperaturas elevadas. Foram modelados pilares sob flexão normal composta considerando a seção transversal aquecida de forma simétrica. Os resultados do programa foram comparados a resultados de ensaios de laboratórios internacionais, com o objetivo de validar as hipóteses de cálculo adotadas. / According to Brazilian Codes, reinforced concrete structures must be verified under high temperatures, in order to assure the load bearing capacity to allow the safe evacuation of the users and the fire fighting and to reduce the fire spread to other compartments. For reinforced concrete structures, the columns must be analyzed carefully. The significant reduction in the load bearing capacity of reinforced concrete columns in fire can lead to collapse, which could result in global instability of the structure in some cases. The calculation of the fire resistance time of reinforced concrete columns, in the design phase, is usually done by means of simplified methods given by the standards. These methods are very limited and can result in excessively safe solutions (uneconomical) or unsafe solutions in some cases. A computational tool was developed for calculating the fire resistance time of reinforced concrete columns in fire, given symmetrical temperature fields in cross section as a function of exposure time to standard fire. The calculation method was developed using the method based on estimation of curvature given by Eurocode 2 (EN 1992-1-2:2004). The cross section was divided into elements (concrete and steel), in which the thermal strain and thermomechanical properties of each element were calculated according to its temperature. The mechanical behavior of the column under uniaxial bending considered the geometrically nonlinear effects of the structure, which generally become important due to reduced stiffness of the column at elevated temperatures. The results of the numerical analysis and experimental results of full-scale laboratory fire tests on concrete columns performed by international researchers were compared in order to validate the main hypothesis adopted.

Nas últimas décadas, considerável evidência tem sido direcionada no desenvolvimento de métodos computacionais que analisam os comportamentos não lineares das estruturas. O método da corda é considerado o tipo de método de seguimento de trajetórias que possui a técnica mais comum e versátil para analisar tais comportamentos não lineares. No entanto, testes realizados pelos autores concluem que tais métodos ainda apresentam algumas dificuldades quando as estruturas possuem formas complexas e comportamentos fortemente não lineares. Devido a isso, o objetivo do trabalho em questão é acrescentar duas modificações ao método da corda, a fim de desenvolver um modelo mais seguro e estável. A esses métodos, inclui-se (i) uma equação alternativa para o passo previsor, que tornará o método mais estável ao ultrapassar pontos críticos; e (ii) um parâmetro de controle, que através do conceito de soma dos comprimentos de corda, é chamado de método da corda acumulado. Ao final, por consequência destas alterações, um procedimento mais robusto para o método da corda é obtido. Sua validação é apresentada, pelos autores, através de exemplos utilizando estruturas treliçadas (bidimensionais e tridimensionais) em um programa de simulação numérica desenvolvida. / In the last decades, a considerable effort has been directed to develop of computational methods to analyze the nonlinear behavior of structures. The arc-length method is considered the type of path following method which have the most common and versatile techniques for analyzing such nonlinear behaviors. Nevertheless, tests performed by the authors conclude that such methods present some difficulties when the structures possess complex shapes and strongly nonlinear behaviors. Due to this, the purpose of the present work is to add two amendments to the arc-length method, in order to develop a model safer and more stable. In such methods, it is included (i) an alternative equation for the predictor step, that will make the method most stable to overcoming critical points, and (ii) a control parameter, through the concept of sum of the arc length up to now, referred to as accumulated arc-length method. By the end, as a result of these modifications, a more robust procedure for the method of the string is obtained. And its validation is presented by the authors through examples using truss structures in a two-dimensional and three-dimensional numerical simulation program developed.

A análise estrutural dos pavimentos de edifícios vem se constituindo de recursos cada vez mais refinados, com a difusão de inúmeros \"softwares\", dotados de pré e pós-processadores que possibilitam análises precisas, com a consideração da interação entre as rigidezes de todos os elementos que compõem o sistema estrutural do pavimento. Entretanto, há que se ressaltar que, diante desta ampla disponibilidade de recursos, os cálculos simplificados não podem ser deixados de lado nas análises dos projetistas, uma vez que propiciam confirmações dos resultados fornecidos por um \"software\". Assim sendo, o presente trabalho apresenta alguns aspectos da análise estrutural das lajes de edifícios, abordando conceitos relativos a ações e disposições construtivas a considerar nos projetos, ao pré-dimensionamento das lajes e aos tipos de análise estrutural possíveis de serem realizadas. São apresentados alguns modelos estruturais para análise linear das lajes de edifícios, a saber, o cálculo aproximado mediante tabelas do método elástico, a técnica da analogia de grelha e o método dos elementos finitos, mostrando as particularidades de cada um e definindo até que ponto cada um deles pode ser aplicado com segurança, apresentando resultados coerentes para o comportamento estrutural. No regime elasto-plástico, é apresentado um modelo estrutural de análise através da teoria das charneiras plásticas. São abordadas, para cada um dos modelos estruturais propostos, questões relativas à distribuição das armaduras e aos valores de esforços solicitantes a considerar para o correto dimensionamento das lajes do pavimento. Apresentam-se, ainda, os detalhamentos das armaduras positivas e negativas resultantes das análises realizadas. / The structural analysis of building pavements has been made through the use of very sophisticated instruments, with the dissemination of severa! softwares, characterized by pre- and post-processors which enable accurate analysis, considering the interaction between the stiffness of ali the elements that constitute the pavement structural system. lt is important to notice that even with the large number of available resources, simplified calculations cannot be disregarded in a designer\'s analysis, since they provide the confirmation of the results yielded by the software. So, this study presents some aspects of building slabs structural analysis, regarding concepts related to actions and constructive dispositions to be considered in such projects, to slabs pre-design and kinds of possible structural analysis. Some structural models for linear analysis of building slabs are presented: (1) the simplified calculation through the use of tables of elastic method; (2) crossing beams analogy technique and (3) the finite element method, showing the characteristics of each one and defining up to what point each of them can be used safely, presenting coherent results to structural behavior. In the elastic-plastic regime, a structural model of analysis through the yield line theory is presented. For each proposed structural model, questions about arm distribution and values of requested efforts are considered, regarding the correct pavement slabs design. The details regarding positive and negative arms resulting from the analysis performed is also presented.