摘要
为了评估双相冷成型钢高温冷却后的力学性能,采用箱式炉对试件进行加热升温至300~1 000℃,在指定温度下分别保温15min和60min,自然冷却后进行拉伸试验,得到双相冷成型钢过火后的应力-应变曲线、弹性模量、屈服强度、抗拉强度和断后伸长率。结果表明,保温时间对过火后材性有显著影响,保温时间越长,材料力学性能的衰减越明显;另一方面,双相冷成型钢的过火后力学性能随着过火温度的升高而降低,但在600~800℃温度区间有显著的回升。因此,相关研究的预测公式不适用于过火后的双相冷成型钢,在过火后材性试验数据的基础上,给出了基于不同保温时间的双相高强冷成型钢高温后强度折减预测公式。
In order to evaluate the post-fire mechanical properties of cold-formed dual-phase steel,the specimen was heated to specified temperatures ranged from 300 to 1 000 ℃ with an electric furnace.The holding time for the test coupons at the specified temperatures was 15 and 60 min,then the tensile test was carried out after natural cooling.The post-fire strain-stress curve,elastic modulus,yield strength,ultimate strength and fracture strain for cold-formed dual-phase steel were obtained.The results show that the holding time significantly affects the post-fire material properties of cold-formed dual phase steel,the decrease on material properties was observed with the increase of holding time.On the other hand,the deterioration of mechanical properties of cold-formed dual-phase steel decrease was observed with the increase of elevated temperatures,but a recovery was found in the temperature within 600-800 ℃.Therefore,the relevant predictions are not applicable to the post-fire cold-formed dual-phase steel.Based on the results of material properties,aprediction for post-fire material properties of high strength cold-formed dual phase steel with different holding time is proposed.
作者
张佳慧
盛孝耀
ZHANG Jiahui;SHENG Xiaoyao(School of Environment and Architeeture,University of Shanghai for Science andTechnology,Shanghai 200093,China)
出处
《建筑钢结构进展》
CSCD
北大核心
2020年第5期26-34,共9页
Progress in Steel Building Structures
基金
国家自然科学基金(51508328)。
关键词
双相冷成型钢
高温后
力学性能
强度折减系数
cold-formed dual phase steel
post-fire
mechanical properties
strength reduction coefficient
