结构用钢(16Mn)恒载加温试验研究

Research on steel structure 16Mn by heating tests under constant loads

利用WAW-1000微机控制伺服万能试验机对四大钢厂的钢材进行了182次恒载加温试验。荷载水平分为0.25、0.3、0.35、0.4、0.45、0.5、0.55、0.6、0.65、0.7、0.75、0.8、0.85共13个应力水平,温度为200℃、300℃、350℃、400℃、450℃、500℃、550℃、600℃共8个水平。通过对总变形分离成荷载变形、膨胀变形、温度应力耦合变形三部分,以试验取得的数据进行回归,得到各变形的经验计算公式,并构建出该类国产钢材的应变-温度-应力材料模型和临界温度计算模型。根据该模型,当屈服应变已知时,可由临界温度计算模型反推出临界温度,为钢结构保护层厚度计算提供方便。此外,利用该材料模型可为钢结构抗火整体分析提供一定的理论支持。

In this paper, by WAW-1000 computer control testing machine, heating device and specially designed deformation measuring appliance, experiments have been carried out to investigate the mechanical behavior of steel structure 16Mn from China＇s four major steelworks at elevated temperatures by heating tests under constant loads. In all 182 tests were conducted by stress levels from 0. 25 to 0. 85 with a step of 0. 05, and by temperatures from 200℃ to 600℃. Based on the experiments results, a stress-strain-temperature relationship model and a critical temperature model have been developed. The critical temperature obtained by the known yield strain can be used to calculate the thickness of covering layer. In steel structure fireresisting design and evaluation, the calculation of the temperature stress and deformation of steel structure depends on the stress-strain-temperature material model, which can be applied in performance-based fire resisting design and steel structure evaluation.