Abstract
Cantilevers are unique statically determinate structural elements with respect to their mode of overall buckling, in that the tension flange is the critical flange under gravity loading, and is the flange that deflects greatest during overall buckling. While this phenomenon does not complicate the calculation of the lateral buckling load, either theoretically or in structural design codes, it has been shown in previous research that the influence of distortion in the elastic buckling of cantilevers is not the same as that experienced in the elastic buckling of simply supported beams. This paper extends the study of the distortional buckling of cantilevers into the hitherto unconsidered inelastic range of structural response. A finite element method for studying the inelastic bifurcative instability of members whose cross-sections may distort during buckling is described, and the efficacy of the method is demonstrated. It is then used to study the inelastic distortional buckling of hot-rolled I-section cantilevers with two common patterns of residual stresses, and which may be restrained elastically from buckling by other structural elements.
Key Words
buckling; cantilevers; distortional buckling; inelasticity; residual stresses; restraints.
Address
Department of Civil, Urban and Geosystem Engineering, Seoul National University, Seoul 51-752, KorearnSchool of Civil and Environmental Engineering, The University of New South Wales, UNSW Sydney, NSW 2052, Australia
Abstract
In this paper design and fabrication information system for steel bridge construction is studied and proposed according to the progress of Construction CALS/EC in the construction industry in Japan. The data exchange in this system bases on the text file as well as CAD data with simplified drawings. The concept of this system is discussed following the analysis on the issues of the conventional system. The application of the product model is also discussed including effects and issues on the inspection system. This paper is based on the study carried out by Special Committee on Construction CALS of JASBC to which author belong.
Key Words
CALS/EC; steel bridge; fabrication; data exchange; auto CAD; CAM; inspection; product model.
Address
Steel Structure Department, NKK Corporation, 1-1-2, Marunouchi, Chiyoda-Ku, Tokyo 100-8202, JapanrnYokogawa Bridge Co. Ltd., 27, Yamano-Cho, Funabashi, Chiba 261-0002, JapanrnJapan Association of Steel Bridge Construction, 2-2-18, Ginza, Tokyo 104-0061, Japan
Abstract
This study focuses on the influence of a composite external strengthening on the natural frequencies of a steel beam with open cracks. In a first step, the leading parameters associated with the effect of the composite strengthening are experimentally identified. An analytical model is developed in order to quantify the importance of the force transfer within the resin interface. In a second step, the analytical model of a cracked beam with composite external strengthening is compared to experiments.
Address
Laboratoire M?canique Mat?riaux et Structures, Universit? Claude Bernard, 82 boulevard Niels Bohr, Domaine scientifique de la Doua, 69622 Villeurbanne, France
Abstract
In a nonlinear finite element study on the mechanical behavior of simple beam connections to continuous concrete-filled steel tube columns, two principally different connection types were analyzed: one with plates attached to the outside of the tube wall, relying on shear transfer, and one with an extended plate inserted through the steel section to ensure bearing on the concrete core. The load was applied partly at the connection within the column length and partly at the top, representing the load from upper stories of a multi-story building. The primary focus was on the increased demand for load transfer to ensure composite action when concrete with higher compressive strength is used. The results obtained from the analyses showed that the design bond strength derived from push tests is very conservative, mainly due to the high frictional shear resistance offered by pinching and contraction effects caused by connection rotation. However, with higher concrete strength the demand for load transfer increases, and is hard to fulfill for higher loads when connections are attached only to the steel section. Instead, the connection should penetrate into the concrete core to distribute load to the concrete by direct bearing.
Key Words
composite columns; concrete-filled steel tube; composite action; bond; connections; finite element analysis.
Address
Department of Structural Engineering, Concrete Structures, Chalmers University of TechnologyrnSE-412 96 G?teborg, Sweden
Abstract
A higher level of engineering standard in the field of construction, is the use of prestressing in building structures. The concept of prestressing steel structures has only recently been widely considered, despite a long and successful history of prestressing concrete members. Several analytical studies of prestressed steel girders were reported in literatures, but much of the work was not studied with reference to the optimal design and behaviour of the prestressed steel plate girder. A plate girder prestressed eccentrically, will behave as a beam-column, which is subjected to axial compression and bending moment which will cause the beam to buckle out. The study of buckling of the prestressed steel plate girder is necessary for stability criteria. This paper deals with the stability of prestressed steel plate girder using concept of
Key Words
prestressing; plate girder; torsion, buckling, stability; Vlasov
Address
Department of Structural Engineering and Applied Mechanics, Visvesvaraya National Institute of Technology, Nagpur 440 011, India
