Post-fire performance evaluation of steel connections under a column-loss scenario

Abstract

This study evaluates the post-fire performance of steel connections under a column-loss scenario. A series of fire tests, coupon tests and cyclic loading tests were carried out on 5 sets of 1/3-scaled SN400YB steel H-beam-to-H-column connections. After exposure to temperatures reaching 800 °C, the connections do not indicate any beam residual deformations or column drifts, and the steel properties, such as yield strength, tensile strength, and elongation, still meet the design requirements for room temperature. Under cyclic loading testing, fracture occurs in the base metal of beam flanges near the column faces of the connections subjected to high temperature and room temperature. Moreover, all the connections developed a moment strength greater than the 80% of nominal plastic moment strength of the beam after the first loading cycle with a drift angle of 0.04 rad. Finite element analyses were also conducted to simulate the test results, showing the severity of a column-loss scenario and the minor effect of initial heating rates. The results obtained from this work show the structural robustness of steel connections against earthquake shaking following a fire accident.

Keywords

• Steel connections
• Post-fire behavior
• Performance evaluation
• Cyclic test
• Finite element analyses