Even though creep behavior in steel at elevated temperatures has been widely observed, the effect of creep on steel members is not fully understood yet due to the extensive range of steel grades. In this paper, a tension creep test on high-strength Q960 steel at high temperatures was performed. Based on the test data in this paper and available creep data on Q345, Q460, and Q690 steels, a consistent creep model for each steel according to the Fields & Fields creep model was proposed and validated by the comparison with the test data. In order to quantitatively investigate the effect of creep on fire response of restrained steel beams, a finite element model (FEM) was established to analyze the critical temperature of restrained steel beams in fire conditions, with and without considering creep strain generated in steel beams. This was also carried out to better understand the impact of high-temperature on steel beams with various steel grades under the influence of the same load. The verification of the FEM was achieved by comparing the results with experimental data on a restrained Q235 steel beam and Q690 cantilever steel beam. The study reveals that creep has a noticeable effect on the fire resistance of the restrained steel beams and that the effect varies from one type of steel to another. A comparison has been made to observe the effect of high-temperature creep on the critical temperature for each steel type.

尽管钢在高温下的蠕变行为已被广泛观察到，但由于钢种范围广泛，因此尚未完全了解蠕变对钢构件的影响。本文对高强Q960钢进行了高温拉伸蠕变试验。根据本文的试验数据和 Q345、Q460 和 Q690 钢的可用蠕变数据，根据 Fields & Fields 蠕变模型提出了每种钢的一致蠕变模型，并通过与试验数据的比较进行了验证。为了定量研究蠕变对受约束钢梁火灾响应的影响，建立有限元模型（FEM）来分析受约束钢梁在火灾条件下的临界温度，考虑和不考虑钢梁产生的蠕变应变。这样做也是为了更好地了解高温对不同钢种钢梁在相同载荷作用下的影响。FEM 的验证是通过将结果与约束 Q235 钢梁和 Q690 悬臂钢梁的实验数据进行比较来实现的。研究表明，蠕变对受约束钢梁的耐火性有显着影响，而且这种影响因钢种而异。已经进行了比较以观察高温蠕变对每种钢的临界温度的影响。FEM 的验证是通过将结果与约束 Q235 钢梁和 Q690 悬臂钢梁的实验数据进行比较来实现的。研究表明，蠕变对受约束钢梁的耐火性有显着影响，而且这种影响因钢种而异。已经进行了比较以观察高温蠕变对每种钢的临界温度的影响。FEM 的验证是通过将结果与约束 Q235 钢梁和 Q690 悬臂钢梁的实验数据进行比较来实现的。研究表明，蠕变对受约束钢梁的耐火性有显着影响，而且这种影响因钢种而异。已经进行了比较以观察高温蠕变对每种钢的临界温度的影响。