An experimental study of connections between I-beams and concrete filled steel tubular columns

Silvana De Nardin,Ana Lucia H. C. El Debs 국제구조공학회 2004 Steel and Composite Structures, An International J Vol.4 No.4

Frame composed of concrete-filled steel tubular columns and I-shaped steel beam has been researched in order to development reasonable connection details. The present paper describes the results of an experimental program in four different connection details. The connection details considered include through-bolt between I-shaped steel beams and concrete-filled steel tubular columns and two details of welded connections. One of the welded connection details is stiffened by angles welded in the interior of the profile wall at the beam flange level. The specimens were tested in a cruciform loading arrangement with variable monotonic loading on the beams and constant compressive load on the column. For through-bolt details, the contribution of friction and bearing were investigated by embedding some of the bolts in the concrete. The results of the tests show that through-bolt connection details are very ductility and the bearing is not important to the behavior of these moment connections. The angles welded in the interior of the profile wall increase the strength and stiffness of the welded connection detail. In addition, the behavior curves of these connections are compared and some interesting conclusions are drawn. The results are summarized for the strength and stiffness of each connection.

Priest and Patriarch in Elizabeth Inchbald`s A Simple Story

( Jane Baron Nardin ) 한국영미문학페미니즘학회 2009 영미문학페미니즘 Vol.17 No.2

Critics have argued that Sandford and Dorriforth, the male protagonists of A Simple Story (1791), behave inconsistently for reasons that remain enigmatic. The two men do indeed exhibit the sort of wayward behavior that was usually coded "feminine" in the late eighteenth century. But their motives are not enigmatic. Sandford and Dorriforth are complex characters whose behavior reveals significant fissures within eighteenth-century patriarchy. Each man defines his obligations in terms of multiple masculine roles. Sandford feels obligated to enforce the father`s law as a former Jesuit and a secular priest. Dorriforth feels obligated to enforce it as a secular priest, a guardian, the head of a family, and an aristocrat. In struggling to fulfill their obligations, the men find that patriarchal precepts are in conflict with one another. By relating their conduct to the history of the Roman Catholic "mission" in England and to the situation of the Jesuits after the order`s suppression in 1773, we can understand their motives, especially those of Sandford. Through these two characters, Inchbald analyzes the often self-defeating nature of patriarchal law and suggests that it undermines the very distinctions of gender it aims to sustain.

Shear transfer mechanisms in composite columns: an experimental study

Silvana De Nardin,Ana Lucia H. C. El Debs 국제구조공학회 2007 Steel and Composite Structures, An International J Vol.7 No.5

In the design of concrete filled composite columns, it is assumed that the load transfer between the steel tube and concrete core has to be achieved by the natural bond. However, it is important to investigate the mechanisms of shear transfer due to the possibility of steel-concrete interface separation. This paper deals with the contribution of headed stud bolt shear connectors and angles to improve the shear resistance of the steel-concrete interface using push-out tests. In order to determine the influence of the shear connectors, altogether three specimens of concrete filled composite column were tested: one without mechanical shear connectors, one with four stud bolt shear connectors and one with four angles. The experimental results showed the mechanisms of shear transfer and also the contribution of the angles and stud bolts to the shear resistance and the force transfer capacity.

Shear transfer mechanism in connections involving concrete filled steel columns under shear forces

Silvana De Nardin 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.4

This paper reports the experimental results of three through bolt beam-column connections under pure shear forces using modified push-out tests. The investigated specimens include extended end-plates and six through-bolts connecting square concrete-filled steel tubular column (S-CFST) to steel beams. The main goal of this study is to investigate if and how the mechanical shear connectors, such as steel angles and stud bolts, contribute to the shear transfer mechanisms in the steel-concrete interface of the composite column. The contribution of shear studs and steel angles to improve the shear resistance of steel-concrete interface in through-bolt connections was investigated using tests. The results showed that their contribution is not significant when the beam-column connection is included in the push-out tests. The specimens failed by pure shear of the long bolts, and the ultimate load can be predicted using the shear resistance of the bolts under shear forces. The predicted values of load allowed obtaining a good agreement with the tests results.

Partially encased composite columns using fiber reinforced concrete: experimental study

Margot F. Pereira,Silvana De Nardin,Ana L.H.C. El. Debs 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.6

This paper addresses the results of an experimental study involving 10 partially encased composite columns under concentric and eccentric compressive loads. Parameters such as slenderness ratio, ordinary reinforced concrete and fiber reinforced concrete, load eccentricity and bending axis were investigated. The specimens were tested to investigate the effects of replacing the ordinary reinforced concrete by fiber reinforced concrete on the load capacity and behavior of short and slender composite columns. Various characteristics such as load capacity, axial strains behavior, stiffness, strains on steel and concrete and failure mode are discussed. The main conclusions that may be drawn from all the test results is that the behavior and ultimate load are rather sensitive to the slenderness of the columns and to the eccentricity of loading, specially the bending axis. Experimental results also indicate that replacing the ordinary reinforced concrete by steel fiber reinforced concrete has no considerable effects on the load capacity and behavior of the short and slender columns and the proposed replacement presented very good results.

Structural behavior of partially encased composite columns under axial loads

Margot F. Pereira,Silvana De Nardin,Ana L.H.C. El Debs 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.6

This paper presents the results of experimental and numerical model analyses on partially encased composite columns under concentric loads. The main objective of this study is to evaluate the influence of replacing the conventional longitudinal and transverse steel bars by welded wire mesh on the structural behavior of these members under concentric loads. To achieve these goals experimental tests on four specimens of partially encased composite columns submitted to axial loading were performed and the results were promising in terms of replacing the traditional reinforcement by steel meshes. In addition, a numerical FE model was developed using the software DIANA® with FX+. The experimental results were used to validate the numerical model. Satisfactory agreement between experimental and numerical results was observed in both capacity and deformability of the composite columns. Despite of the simplifying assumptions of perfect bond between steel and concrete, the numerical model adequately represented the columns behavior. A finite element parametric study was performed and parameters including thickness of the steel profile and the concrete and steel strengths were evaluated. The parametrical study results found no significant changes in the partially encased columns behavior due to variations of the steel profile thickness or yield strength. However, significant changes in the post peak behavior were observed when using high strength concrete and these results suggest a change in the failure mode.

Genetic variants of inducible costimulator are associated with allergic asthma susceptibility

Andiappan, Anand Kumar,Narayanan, Sriram,Myers, Rachel A.,Lee, Bernett,Nieuwenhuis, Maartje A.,Nardin, Alessandra,Park, Choon-Sik,Shin, Hyoung Doo,Kim, Jeong-Hyun,Westra, Harm-Jan,Franke, Lude,Esko, T Elsevier 2015 The journal of allergy and clinical immunology Vol.135 No.2