Techno Press
Tp_Editing System.E (TES.E)
Login Search


scs
 
CONTENTS
Volume 4, Number 4, August 2004
 

Abstract
In view of the mounting cost of rehabilitating deteriorating infrastructure, further compounded by intensified environmental concerns, it is now obvious that the evolvement and application of advanced composite structural materials to complement conventional construction materials is a necessity forrnsustainable construction. This study seeks alternative fill materials (polymer-based) to the much-limited cement concrete used in concrete-filled steel tubular structures. Polymers have been successfully used in other industries and are known to be much lighter, possess high tensile strength, durable and resistant tornaggressive environments. Findings of this study relating to elasto-plasticrncharacteristics of polymer concrete filled steel composite beams subjected to uniform bending highlight the enormous increase in stiffness, strength and ductility of the composite beams, over the empty steel tube. Moreover, polymer based materials were noted to present a wide array of properties that could be tailored to meet specific design requirements e.g., ductility based design or strength based design. Analytical formulations for design are also considered.

Key Words
composite section; polymer concrete; flexural strength.

Address
Walter O. Oyawa; Department of Civil Engineering, JKUAT, P.O. Box 62000-00200, Nairobi, KenyarnKunitomo Sugiura

Abstract
The paper begins by presenting a unified variational approach to the lateral-torsional buckling (LTB) analysis of doubly symmetric prismatic and tapered thin-walled beams with open cross-sections, which accounts for the influence of the pre-buckling deflections. This approach (i) extends the kinematical assumptions usually adopted for prismatic beams, (ii) consistently uses shell membrane theory in general coordinates and (iii) adopts Trefftz

Key Words
lateral-torsional buckling; thin-walled beams; prismatic and web-tapered I-beams; pre-buckling deflections; variational formulation; Rayleigh-Ritz method.

Address
A. Andrade; Department of Civil Engineering, FCT, University of Coimbra, Polo II,rnPinhal de Marrocos, 3030 Coimbra, PortugalrnD. Camotim; Dept. of Civil Engineering, ICIS/IST, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal

Abstract
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 rnthrough-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.

Key Words
concrete filled steel tubular columns; connections; bolted connections; welded connections; through-bolt connections; beam-column connection behavior; extended endplate.

Address
Silvana De Nardin and Ana Lucia H. C. El Debs;rnDepartment of Structural Engineering, University of Sao Paulo at Sao Carlos, rnSao Carlos, Brazil

Abstract
The lateral sway of a multi-storey steel frame should be limited so as to ensure the comfort of the occupants and for the protection of mechanical and architectural systems. This paper investigates the applicability of Schueller\'s equation for predicting sway of rigid steel frames, and proposes a number of modifications to the equation so that it can produce results that are almost identical to those given by accurate Finite Element (FE) analysis. The behaviour of irregular steel frames has also been studied and proposals are made so that Schueller\'s Equation can also be used to predict sway of such frames.

Key Words
FE analysis; steel frames; sway; rigid connection.

Address
M. Ashraf and D. A. Nethercot;rnDepartment of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, U.K.rnB. Ahmed; Dept. of Civil Engineering, Bangladesh Univ. of Engineering and Technology, Dhaka-1000, Bangladesh


Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2017 Techno-Press
P.O. Box 33, Yuseong, Daejeon 34186 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: info@techno-press.com