Submitted by RAFAEL AGUERA REZENO DA SILVA null (aguera.feg@gmail.com) on 2016-04-10T23:05:59Z No. of bitstreams: 1 Dissertação_Aguera.pdf: 5287076 bytes, checksum: 018a793b7d2956814528ec0cb549cc66 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-04-12T17:53:04Z (GMT) No. of bitstreams: 1 silva_rar_me_guara.pdf: 5287076 bytes, checksum: 018a793b7d2956814528ec0cb549cc66 (MD5) / Made available in DSpace on 2016-04-12T17:53:04Z (GMT). No. of bitstreams: 1 silva_rar_me_guara.pdf: 5287076 bytes, checksum: 018a793b7d2956814528ec0cb549cc66 (MD5) Previous issue date: 2016-02-16 / Em bielas automotivas, os parafusos atuam de maneira a manter a união entre capa e haste, suportando as cargas trativas, compressivas e transversais originadas no olhal maior. Para tais componentes, o dimensionamento de juntas aparafusadas torna-se complexo, visto que a disposição dos parafusos e a geometria do mancal conduzem ao surgimento de esforços excêntricos à face de fratura, elevando a criticidade do projeto. Em vista disso, e do reduzido número de publicações sobre o assunto, o presente trabalho propôs uma “abordagem híbrida” para a análise de juntas aparafusadas em bielas anguladas, utilizando resultados obtidos a partir de um modelo de elementos finitos simplificado e as ferramentas contidas no roteiro VDI 2230 parte 1. Além disso, foi avaliada a influência do fenômeno de abertura unilateral sobre a vida em fadiga dos fixadores utilizados em bielas anguladas, analisando os resultados obtidos de modo a desenvolver um critério de avaliação para a fadiga desses componentes. A despeito das restrições, a abordagem numérico-analítica desenvolvida demostrou-se atraente, tanto pelo baixo custo computacional associado, quanto por sua precisão, principalmente na determinação da força tensora residual mínima para a prevenção de abertura, mostrando-se adequado para processos de otimização multiparamétricos, selecionando designs promissores passíveis de posterior avaliação através de modelos refinados. Já as análises de influência do fenômeno abertura não apresentaram alterações sensíveis nos níveis de força adicional dos fixadores, fato esse relacionado com a posição dos pontos de abertura em relação ao parafuso e ao mancal. Apesar disso, as simulações realizadas demonstraram que as condições de carregamento avaliadas não influenciaram no diagrama de Haigh local dos nós críticos de cada fixador, o que sugere o uso de resultados extraídos de ensaios de fadiga como variáveis de entrada para simulações em juntas de bielas, incluindo assim as influências benéficas do processo de manufatura. / Connecting rods screws maintain the connection between cap and shank supporting the tensile, compressive and transversal loads applied on the big end. In this case, the design of bolted joints become complex since the screw’s position and bearing geometry lead to eccentric forces acting on the joint split line. Due to that and the reduced number of publications on the subject, this dissertation aims to develop a "hybrid approach" for the analysis of bolted joints in angled connecting rods, using results from a simplified finite element model as input for the VDI 2230 part 1 guideline. In addition to that, this study evaluates the influence of unilateral opening phenomenon on fasteners fatigue life, analyzing the results in order to develop a criterion for fatigue analysis of connecting rod bolts. Despite the restrictions, the “hybrid approach” proved to be attractive due to the low computational cost and accuracy, especially for the calculation of minimal residual tensile force to prevent opening, being suitable for multiparametric optimization during project early phases. The opening phenomenon showed no significant changes in fastener’s additional forces, fact related to the position of joint opening points. Nevertheless, the simulations showed that the loading conditions did not influence on the local Haigh diagram of critical nodes, which suggests the use of fasters fatigue tests as input variables for fatigue simulations, thus including the beneficial influences of the manufacturing process.

Este trabalho aborda ligações semi-rígidas com o objetivo de verificar a influência da flexibilidade na análise de estruturas metálicas, com o propósito de apresentar um modelo que represente o real comportamento das conexões assumindo uma situação intermediária entre totalmente rígida e totalmente flexível. Os procedimentos empregados para determinar as propriedades destas conexões estão embasados nos métodos descritos pelo anexo J do Eurocode 3 e recomendações do BCSA/SCI. Com intuito de automatizar o cálculo das conexões semi-rígidas foi implementado um programa computacional que fornece as propriedades necessárias das ligações entre vigas e pilares através da entrada de dados geométricos e especificações do material empregado. São abordadas ligações soldadas e ligações parafusadas com chapa de extremidade.O trabalho apresenta, ainda, uma avaliação da redistribuição de solicitações nas estruturas de aço. Fazendo a análise de um pórtico plano empregando molas rotacionais nos nós de encontro entre vigas e pilares inserindo a rigidez rotacional obtida através dos procedimentos numéricos apresentados neste trabalho. Esta mesma estrutura foi analisada da maneira tradicional, ou seja, considerando nós rígidos no encontro entre vigas e pilares. Através da analogia entre os resultados obtidos pelas duas análises é possível visualizar a diferença entre a distribuição nas solicitações. Dessa forma, é possível verificar a influência da rigidez das ligações na análise das estruturas metálicas. / This work approaches semi-rigid connections with the purpose to verify the influence of connections in the analysis of steel structures, with the intention to present a model that represents the real behavior of the connections assuming an intermediate situation between totally rigid and totally pinned. The used procedures to determine the properties of these connections are based in the described methods for the Annex J of the Eurocode 3 and BCSA/SCI. With intention to speed the calculations of the semi-rigid connections a computational program was implemented that supplies to the necessary properties of the connections between beams and columns through the geometric data entry and specifications of the employed material. They are boarded welded connections and connections bolted with extend end plate. The work presents, still, an evaluation of the new distribution of loads in the steel structures. Making the analysis of a plain frame using rotational springs between beams and columns inserting the gotten rotational rigidity through the presented numerical procedures in this work. This same structure was analyzed in the traditional way, that is, considering rigid we in the meeting between beams and columns. Through the analogy it enters the results gotten for the two analyses is possible to visualize the difference enters the distribution in the requests. Of this form, it is possible to verify the influence of flexibility in the analysis of the metallic structures.

Este trabalho aborda ligações semi-rígidas com o objetivo de verificar a influência da flexibilidade na análise de estruturas metálicas, com o propósito de apresentar um modelo que represente o real comportamento das conexões assumindo uma situação intermediária entre totalmente rígida e totalmente flexível. Os procedimentos empregados para determinar as propriedades destas conexões estão embasados nos métodos descritos pelo anexo J do Eurocode 3 e recomendações do BCSA/SCI. Com intuito de automatizar o cálculo das conexões semi-rígidas foi implementado um programa computacional que fornece as propriedades necessárias das ligações entre vigas e pilares através da entrada de dados geométricos e especificações do material empregado. São abordadas ligações soldadas e ligações parafusadas com chapa de extremidade.O trabalho apresenta, ainda, uma avaliação da redistribuição de solicitações nas estruturas de aço. Fazendo a análise de um pórtico plano empregando molas rotacionais nos nós de encontro entre vigas e pilares inserindo a rigidez rotacional obtida através dos procedimentos numéricos apresentados neste trabalho. Esta mesma estrutura foi analisada da maneira tradicional, ou seja, considerando nós rígidos no encontro entre vigas e pilares. Através da analogia entre os resultados obtidos pelas duas análises é possível visualizar a diferença entre a distribuição nas solicitações. Dessa forma, é possível verificar a influência da rigidez das ligações na análise das estruturas metálicas. / This work approaches semi-rigid connections with the purpose to verify the influence of connections in the analysis of steel structures, with the intention to present a model that represents the real behavior of the connections assuming an intermediate situation between totally rigid and totally pinned. The used procedures to determine the properties of these connections are based in the described methods for the Annex J of the Eurocode 3 and BCSA/SCI. With intention to speed the calculations of the semi-rigid connections a computational program was implemented that supplies to the necessary properties of the connections between beams and columns through the geometric data entry and specifications of the employed material. They are boarded welded connections and connections bolted with extend end plate. The work presents, still, an evaluation of the new distribution of loads in the steel structures. Making the analysis of a plain frame using rotational springs between beams and columns inserting the gotten rotational rigidity through the presented numerical procedures in this work. This same structure was analyzed in the traditional way, that is, considering rigid we in the meeting between beams and columns. Through the analogy it enters the results gotten for the two analyses is possible to visualize the difference enters the distribution in the requests. Of this form, it is possible to verify the influence of flexibility in the analysis of the metallic structures.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17154号 / 工博第3644号 / 新制||工||1553(附属図書館) / 29893 / 京都大学大学院工学研究科建築学専攻 / (主査）教授 中島 正愛, 教授 吹田 啓一郎, 教授 金子 佳生 / 学位規則第4条第1項該当

Cold-formed steel purlin systems are widely used in modem building construction, for supporting the roof and floor structures. The rotational behaviour of beam-to-beam bolted connections, which are used between the sections, significantly affects the performance of purlin systems and is hard to predict. The behaviour models currently available for the connections only offer linear or multilinear predictions with low levels of accuracy. The aim of the research presented in this thesis is to develop and propose a nonlinear, more accurate behaviour model for the sleeved modified Z bolted connections, by means of experimental and numerical analysis. Finite element models are presented for the single-bolt, single-lap connection, sleeved modified Z connections in the simply supported arrangement, and a six-span purlin system. Based on the numerical results that have been validated by the experiments, a nonlinear behaviour model is proposed for the sleeved modified Z connections. In the model, the behaviour of the connections is divided into four stages, based on the dominant mechanism that provides the resistance to the rotation. Different formulas are used in different stages to determine the behaviour of the connection, boundary conditions, and magnitudes of bolt forces. The new model reflects well the true behaviour of the connections, and provides a good understanding of what happens inside the connections. The model reveals the failure pattern of the connections and enables optimization in the design of purl in systems, for improving efficiency in material usage.

The search for new and additional sources of energy -- from sun, wind, waves, and ocean currents -- is necessitating the development of structures in the open environment of the oceans as well as on land. The advantages of round or tubular members for use in such structures are shown; and to avoid the uncertainties of welded joints, two bolted connections are proposed and their feasibility explored.

ABSTRACT The task was to design and assess the supporting structure of the lookout tower. Material steel and wood. The lookout tower is 27.22 m high and decreases in height from the base of the srka. Construction system with continuous columns and horizontal reinforcement.

No description available.

At the calculations group in Sigma Industry East North, the traditional method for evaluating fasteners has been by use of the VDI2230 manual. As the complexity of a model increases the evaluation also becomes harder. The goal of this thesis is to set a robust evaluation method by combining the VDI2230 with the Finite Element (FE) method. Varied topics such as fastener and plate compliance, embedding effect, forces through the fastener and plate, minimum thread engagement length, service loads and the fatigue effect in fasteners is discussed. The flowchart discusses the process flow, as in, where to use the VDI2230 and where the FE method comes into use. The thesis also helps to understand designing of bolts like selection of the bolt diameter of varied applications and is user friendly to handle. The focus is also on reducing the time taken for fastener evaluation and setting up of an in-house technique for the evaluation. The evaluation method is verified using a test case. / På beräkningsgruppen på Sigma Industry East North har den traditionella metoden för utvärdering av fästelement varit att använda sig av manualen VDI 2230. Ökad komplexitet gör utvärderingen svårare att genomföra. Målet med detta examensarbete är att föreslå en robust utvärderingsmetod som kombinerar VDI 2230 med Finita Element-Analys (FEA). Olika ämnen såsom vekhet för fästelement och plåtar, sättningar, kraftvägar genom fästelement eller plåtar, minsta ingreppslängd, laster och utmattningseffekter diskuteras. Flödesdiagrammet avhandlar processflödet, det vill säga var man ska använda VDI2230 och när FE-metoden bör användas. Examensarbetet är också till för att skapa förståelse för hur man konstruerar skruvar, såsom val av skruvdiameter vid olika tillämpningar. Fokus har också varit att minska tidsåtgången för utvärdering av fästelement och att sätta upp tekniker för utvärdering att användas i den dagliga verksamheten. Utvärderingsmetoden verifieras med hjälp av ett provfall.

<p> Trusses and Vierendeel girders are usually built from a single chord HSS "Hollow Structural Sections", but the largest HSS size as produced in Canada may limit its use for longer span applications. Therefore, the possibility of using double chord sections to enable the use of HSS for longer span trusses without the need for manufacturing new larger sections, presented itself. </p> <p> A new concept utilizing double chord square hollow sections in welded K-joints of Warren trusses is described. The experimental results of 29 tests are reported, including four connections types — standard, channel, bolted and back-to-back. The latter type comprised of gapped, overlapped and gapped with connecting stiffener plates. </p> <p> The results indicate that the standard type is an excellent joint in both strength and stiffness. The channel type is generally susceptible to twisting. It was found adequate only when a significant increase in chord thickness (≃ 50%) was employed. The bolted connection appears to hold promise when on-site assembly of large trusses is necessary. Its performance was further improved by connecting the chords with small tie bars. The back-to-back type needed to be reinforced or fully overlapped to develop full branch member strength. </p> <p> The double chord system of connection reveals itself to be much superior in strength to an equivalent single chord joint. </p> <p> The effects of eccentricity, branch member to chord angle, and chord preloading were investigated. Interaction formulae are presented for the standard and channel type joints which suffered from a chord failure at the connection. </p> <p> Results of four T-type connections using the double chord concept are also reported and were recently published in the ASCE (8). </p> / Thesis / Doctor of Philosophy (PhD)