Techno Press


Steel and Composite Structures   Volume 18, Number 6, June 2015, pages 1569-1582
DOI: http://dx.doi.org/10.12989/scs.2015.18.6.1569
 
Mid-length lateral deflection of cyclically-loaded braces
Therese Sheehan, Tak-Ming Chan and Dennis Lam

 
Abstract     [Full Text]
    This study explores the lateral deflections of diagonal braces in concentrically-braced earthquakeresisting frames. The performance of this widely-used system is often compromised by the flexural buckling of slender braces in compression. In addition to reducing the compressive resistance, buckling may also cause these members to undergo sizeable lateral deflections which could damage surrounding structural components. Different approaches have been used in the past to predict the mid-length lateral deflections of cyclically loaded steel braces based on their theoretical deformed geometry or by using experimental data. Expressions have been proposed relating the mid-length lateral deflection to the axial displacement ductility of the member. Recent experiments were conducted on hollow and concrete-filled circular hollow section (CHS) braces of different lengths under cyclic loading. Very slender, concrete-filled tubular braces exhibited a highly ductile response, undergoing large axial displacements prior to failure. The presence of concrete infill did not influence the magnitude of lateral deflection in relation to the axial displacement, but did increase the number of cycles endured and the maximum axial displacement achieved. The corresponding lateral deflections exceeded the deflections observed in the majority of the previous experiments that were considered. Consequently, predictive expressions from previous research did not accurately predict the mid-height lateral deflections of these CHS members. Mid-length lateral deflections were found to be influenced by the member non-dimensional slenderness (
 
Key Words
    cyclic loading; concentrically-braced frames; tubular structures; concrete-filled tubes; earthquake-resisting buildings
 
Address
(1) Therese Sheehan, Dennis Lam:
School of Engineering and Informatics, University of Bradford, Richmond Road, Bradford BD7 1DP, United Kingdom;
(2) Tak-Ming Chan, Dennis Lam:
Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2019 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: technop@chol.com