جستجو در تالارهای گفتگو

Experimental and analytical investigations on seismic behavior of ductile steel knee braced frames Seyed Mehdi Zahrai 1a and Meysam Jalali 2 1 Center of Excellence for Engineering and Management of Civil Infrastructures, School of Civil Engineering, the University of Tehran, Tehran, Iran 2 Department of Civil Engineering, Faculty of Engineering, University of Damghan, Damghan, Iran (Received November 11, 2011, Revised August 30, 2013, Accepted September 16, 2013) Abstract. Knee Braced Frame (KBF) is a special form of ductile eccentrically braced frame having a diagonal brace connected to a knee element, as a hysteretic damper, instead of beam-column joint. This paper first presents an experimental investigation on cyclic performance of two knee braced single span one-story frame specimens. The general test arrangement, specimen details, and most relevant results (failure modes and hysteretic curves) are explained. Some indexes to assess the seismic performance of KBFs, including ductility; response reduction factor and energy dissipation capabilities are also subsequently discussed. Experimental results indicate that the maximum equivalent damping ratios achieved by test frames are 21.8 and 23% for the specimens, prior to failure. Finally, a simplified analytical model is derived to predict the bilinear behavior of the KBFs. Acceptable conformity between analytical and experimental results proves the accuracy of the proposed model. Keywords: knee braced frames; cyclic behavior; ductility; equivalent damping ratio; response reduction factor; simplified model Steel and Composite Structures, Vol. 16, No. 1 (2014) 1-21 DOI: [Hidden Content] منبع: [Hidden Content] دانلود: [Hidden Content] AoJV84uc.pdf