摘要
通过对国产Q420D低合金高强度钢进行高温(200~800℃)拉伸试验,得到在不同试验温度下的弹性模量、屈服强度、抗拉强度、断后伸长率以及应力-应变关系,建立了多项式模型、NIST模型和Ramberg-Osgood (R-O)模型,并与国内外的钢结构抗火设计规范进行对比。利用多项式模型和NIST模型对力学参数的折减系数进行拟合;根据不同温度下的应力-应变曲线,基于R-O模型拟合得到Q420D钢的应力-应变本构模型。结果表明,在200~400℃,Q420D钢的强度、弹性模量和断后伸长率与室温相比下降幅度较小﹐温度超过400℃后,其强度和弹性模量下降速率明显加快,断后伸长率急剧增大。
The elastic modulus,yield strength,tensile strength,elongation after fracture and stress-strain relationship at different test temperatures of domestic Q420D low-alloy high-strength steel were obtained by tensile test at high temperature(200-800℃).The polynomial model,NIST model and Ramberg-Osgood(R-O)model were established,and compared with the domestic and foreign steel structure fire resistance design specifications.The polynomial model and NIST model were used to fit the reduction coefficients of mechanical parameters.According to the stress-strain curves at different temperatures,the stress-strain constitutive model of Q420D steel was obtained by fitting R-O model.The results show that the strength,elastic modulus and the elongation after fracture changes little of Q420D steel decrease less at 200-400℃than that at room temperature.When the temperature exceeds 400℃,the decreasing rate of strength and elastic modulus accelerates obviously,and the elongation after fracture increases sharply.
作者
朱军
盛冬发
幸美秀
宋浩然
毛星波
ZHU Jun;SHENG Dong-fa;XING Mei-xiu;SONG Hao-ran;MAO Xing-bo(School of Civil Engineering,Southwest Forestry University,Kunming 650224,China;School of Mechanics and Civil Engineering,Jinan University,Guangzhou 510600,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2023年第7期172-179,共8页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(11862023)。
关键词
高温拉伸
折减系数
本构模型
低合金高强度钢
high temperature tensile
reduction coefficient
constitutive model
low-alloy high-strength steel
