Sebastião A. L. De Andrade | PUC-RJ (original) (raw)
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Papers by Sebastião A. L. De Andrade
Proceedings of the Seventh International Conference on Computational Structures Technology, 2004
Nowadays, using the Eurocode 3 component method, it is possible to evaluate the rotational stiffn... more Nowadays, using the Eurocode 3 component method, it is possible to evaluate the rotational stiffness and moment capacity of semi-rigid joints when subject to pure bending. However, this component method is not yet able to calculate these properties when, in addition to the applied moment, an axial force is also present. The main aim of this paper is to propose
Este artigo apresenta a metodologia e uma ferramenta para otimização da flexão em estruturas de a... more Este artigo apresenta a metodologia e uma ferramenta para otimização da flexão em estruturas de aço com ligações semi-rígidas, através de algoritmos genéticos. Para tanto se implementou um algoritmo genético no programa FTOOL/SRC [1], que dispõe de uma interface eficiente para o pré-processamento, análise e pós-processamento de estruturas com ligações semi-rígidas. Os resultados comprovam a eficácia do algoritmo genético implementado e da metodologia proposta, visando uma distribuição de momentos fletores na estrutura mais eficiente a partir da variação da rigidez de suas ligações. O presente trabalho constitui uma importante contribuição para a metodologia de projeto estrutural de pórticos em aço, devido à consideração das ligações semi-rígidas.
Journal of Constructional Steel Research, 2009
Traditionally, the steel portal frame design assumes that beam-to-column joints are rigid or pinn... more Traditionally, the steel portal frame design assumes that beam-to-column joints are rigid or pinned. However, it is largely recognized that the great majority of joints do not exhibit such idealized behaviour transmitting bending moments with non-negligible rotations. These joints are called semi-rigid and their design should be performed according to their actual structural behaviour. When minor axis beam-to-column joints are considered, the adopted design process generally assumes a flexible response although this is not true for the great majority of structural joints. Minor axis joints present a distinct behaviour that differentiates them from major axis joints. In fact, the absence of transverse stiffeners implies that the column web must resist all the tensile and compressive forces arising from the beam flanges in bending, akin to a plate supported on its vertical sides. In order to evaluate this component’s behaviour, this paper presents a comparison between results obtained from a finite element model analysis and experiments. The experimental programme was based on the use of reflection photoelasticity techniques to determine the column web stress and strain distribution present in minor axis semi-rigid joints. This technique, although widely used for determining stress and strain distributions in other applications, was first used in this investigation to determine the semi-rigid joints structural response.
… of Constructional Steel …, 2007
This work presents a parametric analysis to evaluate the behaviour of steel beams subjected to co... more This work presents a parametric analysis to evaluate the behaviour of steel beams subjected to concentrated loads.
… of Constructional Steel …, 2004
The use of steel deck slabs has proved over the years to be one of the most economic structural b... more The use of steel deck slabs has proved over the years to be one of the most economic structural building systems. Despite this affirmative, mainly for various historic reasons beyond the scope of the present paper, the Brazilian construction industry has not fully exploited the considerable potential of this structural solution. The first part of this paper presents and discusses the analytical and experimental results of a wide-rib composite steel deck developed at the Structural and Materials Laboratory of PUC-Rio. The steel decks results are centred on the steel/concrete longitudinal shear ultimate limit state, load vs. slab strain curve responses and on steel deck design and detailing recommendations. The final part of the paper focuses on an innovative composite slab system made of a steel deck and a styrofoam plate, side by side, filled with reinforced concrete also developed at PUC-Rio. A parametric analysis of the steel deck profile was first performed. When an optimum steel deck profile was established, the investigation proceeded with a series of full-scale-experiments to access the system’s ultimate and serviceability limit states. The experiments also comprised the study of the concrete vs. steel deck interlocking or mechanical shear transfer devices.
Journal of Intelligent …, 2001
This work presents the application of Artificial Neural Networks to forecast the ultimate resista... more This work presents the application of Artificial Neural Networks to forecast the ultimate resistance of steel beams subjected to patch loads. A single design formula for this structural engineering problem is very difficult to obtain, due to the influence of several independent parameters. On the other hand, creating new experimental data in laboratory is very time consuming and expensive. This work demonstrates that new data can be obtained from a neural network system composed of four Back Propagation networks. The proposed neural network system presented a maximum error value lower than 15%, while the existing formulas errors were over 20%. These results confirmed the possibility of using this methodology to generate new trustworthy data. These data, coupled with experiments found in the literature, can surely help the development of a more consistent and accurate design formula.
Proceedings of the Seventh International Conference on Computational Structures Technology, 2004
Nowadays, using the Eurocode 3 component method, it is possible to evaluate the rotational stiffn... more Nowadays, using the Eurocode 3 component method, it is possible to evaluate the rotational stiffness and moment capacity of semi-rigid joints when subject to pure bending. However, this component method is not yet able to calculate these properties when, in addition to the applied moment, an axial force is also present. The main aim of this paper is to propose
Este artigo apresenta a metodologia e uma ferramenta para otimização da flexão em estruturas de a... more Este artigo apresenta a metodologia e uma ferramenta para otimização da flexão em estruturas de aço com ligações semi-rígidas, através de algoritmos genéticos. Para tanto se implementou um algoritmo genético no programa FTOOL/SRC [1], que dispõe de uma interface eficiente para o pré-processamento, análise e pós-processamento de estruturas com ligações semi-rígidas. Os resultados comprovam a eficácia do algoritmo genético implementado e da metodologia proposta, visando uma distribuição de momentos fletores na estrutura mais eficiente a partir da variação da rigidez de suas ligações. O presente trabalho constitui uma importante contribuição para a metodologia de projeto estrutural de pórticos em aço, devido à consideração das ligações semi-rígidas.
Journal of Constructional Steel Research, 2009
Traditionally, the steel portal frame design assumes that beam-to-column joints are rigid or pinn... more Traditionally, the steel portal frame design assumes that beam-to-column joints are rigid or pinned. However, it is largely recognized that the great majority of joints do not exhibit such idealized behaviour transmitting bending moments with non-negligible rotations. These joints are called semi-rigid and their design should be performed according to their actual structural behaviour. When minor axis beam-to-column joints are considered, the adopted design process generally assumes a flexible response although this is not true for the great majority of structural joints. Minor axis joints present a distinct behaviour that differentiates them from major axis joints. In fact, the absence of transverse stiffeners implies that the column web must resist all the tensile and compressive forces arising from the beam flanges in bending, akin to a plate supported on its vertical sides. In order to evaluate this component’s behaviour, this paper presents a comparison between results obtained from a finite element model analysis and experiments. The experimental programme was based on the use of reflection photoelasticity techniques to determine the column web stress and strain distribution present in minor axis semi-rigid joints. This technique, although widely used for determining stress and strain distributions in other applications, was first used in this investigation to determine the semi-rigid joints structural response.
… of Constructional Steel …, 2007
This work presents a parametric analysis to evaluate the behaviour of steel beams subjected to co... more This work presents a parametric analysis to evaluate the behaviour of steel beams subjected to concentrated loads.
… of Constructional Steel …, 2004
The use of steel deck slabs has proved over the years to be one of the most economic structural b... more The use of steel deck slabs has proved over the years to be one of the most economic structural building systems. Despite this affirmative, mainly for various historic reasons beyond the scope of the present paper, the Brazilian construction industry has not fully exploited the considerable potential of this structural solution. The first part of this paper presents and discusses the analytical and experimental results of a wide-rib composite steel deck developed at the Structural and Materials Laboratory of PUC-Rio. The steel decks results are centred on the steel/concrete longitudinal shear ultimate limit state, load vs. slab strain curve responses and on steel deck design and detailing recommendations. The final part of the paper focuses on an innovative composite slab system made of a steel deck and a styrofoam plate, side by side, filled with reinforced concrete also developed at PUC-Rio. A parametric analysis of the steel deck profile was first performed. When an optimum steel deck profile was established, the investigation proceeded with a series of full-scale-experiments to access the system’s ultimate and serviceability limit states. The experiments also comprised the study of the concrete vs. steel deck interlocking or mechanical shear transfer devices.
Journal of Intelligent …, 2001
This work presents the application of Artificial Neural Networks to forecast the ultimate resista... more This work presents the application of Artificial Neural Networks to forecast the ultimate resistance of steel beams subjected to patch loads. A single design formula for this structural engineering problem is very difficult to obtain, due to the influence of several independent parameters. On the other hand, creating new experimental data in laboratory is very time consuming and expensive. This work demonstrates that new data can be obtained from a neural network system composed of four Back Propagation networks. The proposed neural network system presented a maximum error value lower than 15%, while the existing formulas errors were over 20%. These results confirmed the possibility of using this methodology to generate new trustworthy data. These data, coupled with experiments found in the literature, can surely help the development of a more consistent and accurate design formula.