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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Fire Performance of Connections in Laminated Veneer Lumber

Chuo, Terence Chung Biau January 2007 (has links)
The embedment strength of timber with respect to exposure temperature has not been widely studied. Some studies have suggested that the timber totally loses its embedment strength when the timber temperature reaches 300℃. This research concentrates on the embedment strength study of Laminated Veneer Lumber (LVL) timber product exposed to elevated temperatures up to 250℃ using singly bolted connections. Experiments showed that the embedment strength of LVL decreased at a constant rate from 0.08 kN/mm² to 0.025 kN/mm² once the bolt temperature increased from ambient conditions. The embedment strength was then assumed to remain at strength of 0.025 kN/mm² as the bolt temperature continues to increase from 120℃. The difference between the estimated failure load based on Johansen's Equations and the experimental failure load for the connections tested under fire conditions was less than 30%. The estimation was based on bolt strength reduction using NZS 3404, the experimental charring rate and the experimental embedment strength. The predicted failure mode agreed with experimental for all types of connection.
2

A Model for Prediction of Fracture Initiation in Finite Element Analysis of Bolted Steel Connections

Wurzelbacher, Kenneth P. January 2012 (has links)
No description available.
3

ON THE DESIGN OF BOLTED SPLICES FOR COMPOSITE PLATESHEAR WALLS/CONCRETE FILLED

Anna Pukha (17564337) 10 December 2023 (has links)
<p dir="ltr">This thesis presents the results of the study performed on the behavior of bolted splice</p><p dir="ltr">connections for Concrete Filled Composite Plate Shear Walls. As a part of an experimental</p><p dir="ltr">program, two large-scale specimens employing two different types of fasteners: (i) Hollo-Bolt</p><p dir="ltr">blind bolts, and (ii) threaded rods with pipe sleeves were designed, built, and tested at the Bowen</p><p dir="ltr">Laboratory. The specimens were subjected to monotonic loading to examine the behavior and</p><p dir="ltr">capacity of the proposed connection types. From the results obtained in the experiments it could</p><p dir="ltr">be suggested that the proposed connections are an effective method to connect C-PSW/CFs and</p><p dir="ltr">could be a valuable alternative to Complete Joint Penetration (CJP) welding.</p>
4

The boundary element method and its application to the analysis of bolted connections

Ichikawa, Kazuhiko January 1984 (has links)
No description available.
5

Análise da resposta numérica de ligações parafusadas em chapas finas e perfis formados a frio / Analyzes of the numerical answer of the bolted connections of cold-formed steel members

Rezende, Pedro Gonçalves de 23 September 2005 (has links)
A utilização de perfis formados a frio na construção metálica no Brasil vem crescendo de forma significativa. Dentro deste mesmo contexto, atenções especiais estão sendo direcionadas às ligações utilizadas neste tipo de perfil, pelo fato de as chapas que as constituem resultarem cada vez mais esbeltas em função da significativa redução na sua espessura (elevada relação largura/espessura). Por esta razão, as ligações em perfis formados a frio têm sido estudadas por pesquisadores, tanto no contexto mundial como no Brasil. Neste sentido, o presente trabalho tem por objetivo realizar estudos relacionados às ligações parafusadas em perfis formados a frio, com vistas a avaliar a resistência e o comportamento destas ligações por meio de modelagem numérica, simulando o comportamento estrutural com a utilização do código de cálculo ANSYS v.6.0, elaborado com base nos Métodos dos Elementos Finitos (MEF). No sentido de avaliar a eficiência e a confiabilidade dos modelos elaborados, os resultados numéricos obtidos foram comparados com resultados experimentais obtidos em ensaios, bem como, comparados com resultados numéricos obtidos utilizando-se outros padrões de modelagem. / The use of cold-formed steel members in the steel building in Brazil comes growing of significant form. Inside of the same context, special attentions are being directed to the connections used in the cold-formed steel members, or the fact of the sheets used to this kind of steel members result each time more thin. For this reason the connections in cold-formed steel members have been studied for researchers, as much in the worldwide context as in Brazil. The objective of this work is studies the bolted connections in cold-formed steel member to evaluate the resistance and the behavior of these connections by means of numerical modeling, simulating the structural behavior with the use of the code of calculation ANSYS v.6.0, elaborated based on Finite Element Methods. With the objective to evaluate the efficiency and the trustworthiness of the elaborated model, the numerical results where compare with experimental results gotten in assays, as well as, compared with numerical results gotten using other standards of modeling.
6

Análise da resposta numérica de ligações parafusadas em chapas finas e perfis formados a frio / Analyzes of the numerical answer of the bolted connections of cold-formed steel members

Pedro Gonçalves de Rezende 23 September 2005 (has links)
A utilização de perfis formados a frio na construção metálica no Brasil vem crescendo de forma significativa. Dentro deste mesmo contexto, atenções especiais estão sendo direcionadas às ligações utilizadas neste tipo de perfil, pelo fato de as chapas que as constituem resultarem cada vez mais esbeltas em função da significativa redução na sua espessura (elevada relação largura/espessura). Por esta razão, as ligações em perfis formados a frio têm sido estudadas por pesquisadores, tanto no contexto mundial como no Brasil. Neste sentido, o presente trabalho tem por objetivo realizar estudos relacionados às ligações parafusadas em perfis formados a frio, com vistas a avaliar a resistência e o comportamento destas ligações por meio de modelagem numérica, simulando o comportamento estrutural com a utilização do código de cálculo ANSYS v.6.0, elaborado com base nos Métodos dos Elementos Finitos (MEF). No sentido de avaliar a eficiência e a confiabilidade dos modelos elaborados, os resultados numéricos obtidos foram comparados com resultados experimentais obtidos em ensaios, bem como, comparados com resultados numéricos obtidos utilizando-se outros padrões de modelagem. / The use of cold-formed steel members in the steel building in Brazil comes growing of significant form. Inside of the same context, special attentions are being directed to the connections used in the cold-formed steel members, or the fact of the sheets used to this kind of steel members result each time more thin. For this reason the connections in cold-formed steel members have been studied for researchers, as much in the worldwide context as in Brazil. The objective of this work is studies the bolted connections in cold-formed steel member to evaluate the resistance and the behavior of these connections by means of numerical modeling, simulating the structural behavior with the use of the code of calculation ANSYS v.6.0, elaborated based on Finite Element Methods. With the objective to evaluate the efficiency and the trustworthiness of the elaborated model, the numerical results where compare with experimental results gotten in assays, as well as, compared with numerical results gotten using other standards of modeling.
7

Dynamic Modeling Of Structural Joints

Tol, Serife 01 May 2012 (has links) (PDF)
Complex systems composed of many substructures include various structural joints connecting the substructures together. These mechanical connections play a significant role in predicting the dynamic characteristics of the assembled systems accurately. Therefore, equivalent dynamic models of joints that consist of stiffness and damping elements should be developed and the joint parameters should be determined for an accurate vibration analysis. Since it is difficult to estimate joint parameters accurately by using a pure analytical approach, it is a general practice to use experimental measurements to model joints connecting substructures. In this study an experimental identification method is suggested. In this approach the frequency response functions (FRFs) of substructures and the coupled structure are measured and FRF decoupling method is used to identify equivalent dynamic characteristics of bolted joints. Since rotational degrees of freedom (RDOF) in connection dynamics is very important, a structural joint is modeled with translational, rotational and cross-coupling stiffness and damping terms. FRF synthesis and finite-difference formulations are used for the estimation of unmeasured FRFs and RDOF related FRFs, respectively. The validity and application of the proposed method are demonstrated both numerically and experimentally. In simulation studies, simulated experimental values are used, and it is seen that the identification results are prone to high errors due to noise in measurement and the matrix inversions in the identification equations. In order to reduce the effect of noise, it is proposed to extract the joint properties by taking the average of the results obtained at several frequencies in the frequency regions sensitive to joint parameters. Yet, it is observed in practical applications that experimental errors combine with the measurement noise and the identification results still may not be so accurate. In order to solve this problem, an update algorithm is developed. In the approach proposed, the identified dynamic parameters are used as initial estimates and then optimum dynamic parameters representing the joint are obtained by using an optimization algorithm. The application of the proposed method is performed on a bolted assembly. It is shown with experimental studies that this method is very successful in identifying bolted joint parameters. The accuracy and applicability of the identification method suggested are illustrated by using a dynamically identified bolt in a new structure, and showing that the calculated FRFs in which identified joint parameters are used, match perfectly with the measured ones for the new structure. In this study, the effects of bolt size and quality of bolts, as well as the bolt torque on the joint properties are also studied by making a series of experiments and identifying the joint parameters for each case.
8

Influência da flexibilidade das ligações no projeto de estruturas metálicas

Barbosa, Giovana Daltrozo January 2006 (has links)
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.
9

Influência da flexibilidade das ligações no projeto de estruturas metálicas

Barbosa, Giovana Daltrozo January 2006 (has links)
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.
10

Influência da flexibilidade das ligações no projeto de estruturas metálicas

Barbosa, Giovana Daltrozo January 2006 (has links)
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.

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