portal frame
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EXPERIMENTAL STUDY ON STRUCTURAL CHARACTERISTICS OF PORTAL FRAMES CONSISTING OF SQUARE CFT
COLUMNS
Jun Kawaguchi, Shosuke Morino, Toshikazu Sugimoto and Junya Shirai
Department of Architecture, Mie University
1515 Kamihama-cho, Tsu-shi, Mie, 514-8507 JAPAN
T: 81-59-231-9450; F: 81-59-231-9452; E: jkawa@arch.mie-u.ac.jp
ABSTRACT
In order to clarify the elasto-plastic behavior of the frame consisting of concrete-filled steel tube (CFT) columns and H-shaped steel beams under seismic loading, portal frame specimens were tested under constant vertical loads on columns and alternately repeated horizontal load. Experimental parameters were: axial load ratio (0.15, 0.3 and 0.5) and width-to-thickness ratio (21,39 and 54). Ds factors which are the factor used in the seismic design practice in Japan, were calculated from the load-deflection curves of all specimens. It was observed that all specimens showed fairly stable hysteresis loops, and the earthquake resistant capacity of a CFT frame was better than a similar steel frame.
INTRODUCTION
CFT frames consist of concrete-filled steel tubular (CFT) columns and pure steel beams. They have become very popular these days, since it has been verified by many investigations since the 1970 's that CFT columns have more benefit compared with ordinary steel columns, that is, CFT columns have more load carrying capacity than hollow steel tubular columns due to the interactive effects between steel and concrete; the confining effect of the steel tube on the concrete, and the restraining effect of filled-concrete on the local buckling of the steel tube. However, only a few frame tests have been done which include Matsui 's portal frames (1) and CFT threedimensional subassemblages (2) and portal frames (3) tested by first two authors.
Test results of portal frames were
EXPERIMENTAL STUDY ON STRUCTURAL CHARACTERISTICS OF PORTAL FRAMES CONSISTING OF SQUARE CFT
COLUMNS
Jun Kawaguchi, Shosuke Morino, Toshikazu Sugimoto and Junya Shirai
Department of Architecture, Mie University
1515 Kamihama-cho, Tsu-shi, Mie, 514-8507 JAPAN
T: 81-59-231-9450; F: 81-59-231-9452; E: jkawa@arch.mie-u.ac.jp
ABSTRACT
In order to clarify the elasto-plastic behavior of the frame consisting of concrete-filled steel tube (CFT) columns and H-shaped steel beams under seismic loading, portal frame specimens were tested under constant vertical loads on columns and alternately repeated horizontal load. Experimental parameters were: axial load ratio (0.15, 0.3 and 0.5) and width-to-thickness ratio (21,39 and 54). Ds factors which are the factor used in the seismic design practice in Japan, were calculated from the load-deflection curves of all specimens. It was observed that all specimens showed fairly stable hysteresis loops, and the earthquake resistant capacity of a CFT frame was better than a similar steel frame.
INTRODUCTION
CFT frames consist of concrete-filled steel tubular (CFT) columns and pure steel beams. They have become very popular these days, since it has been verified by many investigations since the 1970 's that CFT columns have more benefit compared with ordinary steel columns, that is, CFT columns have more load carrying capacity than hollow steel tubular columns due to the interactive effects between steel and concrete; the confining effect of the steel tube on the concrete, and the restraining effect of filled-concrete on the local buckling of the steel tube. However, only a few frame tests have been done which include Matsui 's portal frames (1) and CFT threedimensional subassemblages (2) and portal frames (3) tested by first two authors.
Test results of portal frames were
References: Structural Steel Conference, Vol. 2, pp. 169-181, 1986. Concrete II, pp. 726-741, 1992, Potosi, U.S.A.. 4) Structural Requirements for Building Construction, The Building Center of Japan, 1994. 5) AIJ Standard for Structural Calculation of Steel Reinforced Concrete Structures, Architectural Institute of Japan, 1987. of The International Conference on Structural Stability and Design, pp. 295-300, 1995, Sydney, Australia. 7) The Building Standard Law of Japan, The Building Center of Japan, 1986.