No description available.

No description available.

Thesis (Ph.D.)--University of Adelaide, School of Civil and Environmental Engineering, 2003. / Includes bibliographical references (p. 185-189).

Thesis (Ph.D.)--University of Wollongong, 2007. / Typescript. Includes bibliographical references.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Additional advisors: Derrick R. Dean, Alan W. Eberhardt, Ramana G. Reddy, Uday K. Vaidya. Description based on contents viewed Feb. 13, 2009; title from PDF t.p. Includes bibliographical references.

Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references (p. 86-88).

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 330-341). Also available in electronic version.

During propped construction the steel-concrete composite action resists dead as well as imposed loads. Conversely, the steel section alone resists the floor self-weight in unpropped beams. The major difference between propped and unpropped composite beams lies in the ductility requirements rather than in the strength requirements. Relatively few studies have been carried out to assess the rotation requirements for unpropped semi-continuous composite beams. The outstanding critical factor in the case of unpropped construction is the dead load stress that must be carried by the steel beam alone prior to hardening of the concrete. This research overcomes the difficulties involved in modelling the composite and noncomposite stages by using a numerical integration technique developed from the basic principles of structural mechanics. The method incorporates the fully non-linear material properties and requires very little assumption. The technique was initially validated using the experimental results from plain steel beam bending tests. The subsequent comparison between the model predictions and the results from the large-scale frame test carried out for this research purpose, showed that the method is capable of predicting non-elastic load vs. end rotation behaviour within a high degree of accuracy. Thus the model can be used with confidence in order to predict the connection rotation requirements for a wider range of loading configurations than is practically possible from experimental testing alone. A parametric study is carried out using the numerical integration technique developed for the semi-continuous composite beam on a total of 2160 different beam configurations, utilising different steel grades and loading conditions. In this study the influence of dead load stress on the connection rotation requirement has been thoroughly evaluated along with several other factors including span to depth ratio, location within the building frame, ratio between the support (connection) moment capacity and span (beam) moment capacity, loading type, steel grade and percentage of the beam strength utilised during design. The connection rotation capacity requirements resulting from this study are assessed to establish the scope for extending the use of composite connections to unpropped beams. The large-scale experiment that has been carried out provided an opportunity to investigate the behaviour of a modified form of composite connection detail for use at perimeter columns (single-sided composite connections) with improved rebar anchorage. Additionally, another extensive parametric study is carried out using the numerical integration technique developed for the steel beam to establish the influence of strainhardening on elastic-plastic frame instability design.

Orientadores: Paulo Sollero, Éder Lima de Albuquerque / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-23T11:43:13Z (GMT). No. of bitstreams: 1 Souza_CarlosAlexandreOliveirade_D.pdf: 19059891 bytes, checksum: 202a970a88c1bc18c1c8c3304c5b5e47 (MD5) Previous issue date: 2013 / Resumo: Na indústria aeronáutica é de extrema importância o uso de juntas coladas, rebitadas e parafusadas na união de componentes ou partes estruturais. Com o desenvolvimento de novos materiais e novas técnicas de manufatura, as juntas coladas passaram a ser mais utilizadas devido a algumas vantagens sobre as tradicionais juntas rebitadas e parafusadas, tais como: melhor distribuição das tensões na região de colagem, melhor vedação, melhor acabamento, melhor resistência à fadiga, maior eficiência aerodinâmica e o mais importante em aplicações aeronáuticas, menor peso. O projeto de juntas coladas é baseado em análises para a determinação das tensões normais e cisalhantes no adesivo e do campo de deslocamentos ao longo da junta. E no caso de solicitação cíclica, ou seja, fadiga é necessário ainda desenvolver modelos para prever a vida em fadiga de trincas na camada de adesivo e nos aderentes. O objetivo deste trabalho é estudar o comportamento de juntas coladas em estruturas metálicas de aeronaves solicitadas em fadiga, através de modelos analíticos, numéricos e ensaios experimentais. No decorrer do trabalho foram realizados ensaios estáticos, de fadiga e tenacidade à fratura de corpos de prova com juntas coladas. Também foram projetados e testados subcomponentes que representam de forma aproximada, estruturas aeronáuticas reais. As juntas foram modeladas utilizando o software comercial de elementos finitos ABAQUS Ò . Foi ainda, desenvolvido e implementado um modelo semi-analítico para prever a vida em fadiga de juntas coladas baseado em uma formulação proveniente da teoria de vigas e da lei de Paris. E finalmente, foi desenvolvida uma técnica para medir o crescimento da trinca em fadiga durante um ensaio de forma automática, ou seja, sem precisar parar o ensaio para fazer avaliações subjetivas a partir de inspeções visuais / Abstract: In the aeronautical industry is extremely important the use of bonded, riveted and screwed joints for the union of components or structural parts. Through the development of new materials and new manufacturing techniques, the use of bonded joints has increased considerably over recent years. This growth is mainly due to some advantages over the traditional riveted and bolted joints, such as: better stress distributions, better sealing, smoother surface finishes, enhanced fatigue properties, greater aerodynamic efficiency and lower weight, which is an important issue in aeronautical applications. The design of bonded joints is predominantly based on stress analysis as well as the field of displacement along the joint. In the case of cyclic loading, or fatigue, is also necessary to develop models to predict the fatigue life of cracks in the adhesive layer and adherends. The main objective of this work is to study the behavior of bonded joints in metallic aircraft structures under fatigue loading, through analytical models, numerical models and experimental tests. During this work, was carried out static, fatigue and fracture toughness tests. Also was designed and tested subcomponents that represent real aircraft structures. The joints were modeled using the commercial finite element software ABAQUS. It was also developed and implemented a semi-analytical model to predict the fatigue life of bonded joints based on a formulation derived from the theory of beams and the Paris like-law. Finally, was developed a technique to measure the fatigue crack growth during a test automatically, ie, without stopping the test to make subjective evaluations from visual inspections / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

During propped construction the steel-concrete composite action resists dead as well as imposed loads. Conversely, the steel section alone resists the floor self-weight in unpropped beams. The major difference between propped and unpropped composite beams lies in the ductility requirements rather than in the strength requirements. Relatively few studies have been carried out to assess the rotation requirements for unpropped semi-continuous composite beams. The outstanding critical factor in the case of unpropped construction is the dead load stress that must be carried by the steel beam alone prior to hardening of the concrete. This research overcomes the difficulties involved in modelling the composite and noncomposite stages by using a numerical integration technique developed from the basic principles of structural mechanics. The method incorporates the fully non-linear material properties and requires very little assumption. The technique was initially validated using the experimental results from plain steel beam bending tests. The subsequent comparison between the model predictions and the results from the large-scale frame test carried out for this research purpose, showed that the method is capable of predicting non-elastic load vs. end rotation behaviour within a high degree of accuracy. Thus the model can be used with confidence in order to predict the connection rotation requirements for a wider range of loading configurations than is practically possible from experimental testing alone. A parametric study is carried out using the numerical integration technique developed for the semi-continuous composite beam on a total of 2160 different beam configurations, utilising different steel grades and loading conditions. In this study the influence of dead load stress on the connection rotation requirement has been thoroughly evaluated along with several other factors including span to depth ratio, location within the building frame, ratio between the support (connection) moment capacity and span (beam) moment capacity, loading type, steel grade and percentage of the beam strength utilised during design. The connection rotation capacity requirements resulting from this study are assessed to establish the scope for extending the use of composite connections to unpropped beams. The large-scale experiment that has been carried out provided an opportunity to investigate the behaviour of a modified form of composite connection detail for use at perimeter columns (single-sided composite connections) with improved rebar anchorage. Additionally, another extensive parametric study is carried out using the numerical integration technique developed for the steel beam to establish the influence of strainhardening on elastic-plastic frame instability design.