Experimental Investigation on Stability of Circular Steel Tubular Stub Columns at Elevated Temperatures Under Axial Compression

This paper studies the structural stability of circular steel tubular stub columns at elevated temperatures under axial compression. Fifty-one specimens are subjected to high-temperature treatment and axial compression. The variables of the specimen are temperature, wall thickness of steel tube and duration of high temperature. The displacement–load curve, strain–load curve, ultimate load, axial compressive stiffness and failure characteristics of the specimens were analyzed. Test results show that after exposure to high temperatures, the specimens’ failure phenomenon in the axial compression loading test is consistent with that at room temperature, the bearing capacity decreases considerably, the ductility decreases slightly and the axial compressive stiffness changes irregularly. Temperature is the determining factor of the ultimate load of the specimen, and the reducing extent of ultimate load increases with the temperature. When the temperature reaches 1000^∘C, its maximum reducing extent exceeds 50%. Among the three parameters considered in this study, the duration of high temperature has the least influence on the specimen.