Fire Behavior of Composite Beams in Moment Frames

• Main Authors: Tsai, Min-Yen, 蔡旻諺
• Other Authors: 陳誠直
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/43803652336208046460

碩士 === 國立交通大學 === 土木工程系所 === 104 === This study has been conducted experimentally to investigate the behavior of composite beams in moment frames at elevated temperatures and theoretically to evaluate the axial forces within the composite beams. Two specimens were tested to study the effects of the restraint stiffness of the composite beam which provided by different column sizes. Test results demonstrated that the deflection of the composite beams gradually increased due to the deterioration of the material strength at elevated temperatures. When composite beams are subjected to fire, thermal expansion of the composite beams is restrained and compression force is produced, resulting in local buckling at the lower flange and web of the composite beams. For the specimen with larger column section, the maximum axial deformation was reached earlier and the maximum axial deformation was smaller, but the local buckling behavior was more obvious. In addition, it had better fire resistance than the specimen with smaller column section. The theoretical calculation results demonstrated that the compression forces in the specimen with larger column section had a faster increasing rate at the beginning of the test, and local buckling behavior occurred earlier. The theoretical calculation in this study can reasonably predict the axial forces of the composite beams in moment frames.