火灾后方钢管混凝土压弯构件滞回性能理论分析

采用数值计算方法，对ISO-834标准火灾作用后方钢管混凝土压弯构件荷载-位移滞回关系曲线进行理论分析，计算结果与实验结果吻合较好，并比较规程BS5400(1979)、LRFD-AISC(1999)、AU(1997)、EC4(1994)、GJB4142-2000(2001)、DBJ13-51(2003)在进行火灾后方钢管混凝土压弯构件往复荷载作用下极限承载力计算时的差异。在此基础上，对该类构件荷载-位移关系骨架线进行了参数分析，选用的参数包括含钢率、钢材屈服极限、混凝土抗压强度、轴压比、长细比、受火时间。

Cyclic analysis of concrete filled square hollow section columns after exposure to ISO-834 standard fire

This paper presents the results of theoretical studies for concrete filled square hollow section columns subjected to constant axial loading and cyclically increasing flexural loading after exposure to ISO-834 standard fire. The predicted cyclic responses for the composite columns are in good agreement with test results. Comparisons were made with predicted column strengths using the existing codes, such as BS5400 (1979), LRFD-AISC (1999), AIJ (1997), EC4 (1994), GJB4142-2000 (2001) and DBJ13-51 (2003).It is found that all the methods in the codes are somewhat conservative. Influences of parameters on the envelope curves, such as the steel ratio, the steel yielding strength, the concrete strength, the axial load level, the slenderness ratio, and the fire duration were analyzed.