王元清¹, 关阳², 刘明², 顾浩洋¹, 石永久¹
AuthorsHTML:王元清¹, 关阳², 刘明², 顾浩洋¹, 石永久¹
AuthorsListE:Wang Yuanqing¹, Guan Yang², Liu Ming², Gu Haoyang¹, Shi Yongjiu¹
AuthorsHTMLE:Wang Yuanqing¹, Guan Yang², Liu Ming², Gu Haoyang¹, Shi Yongjiu¹
Unit:1. 清华大学土木工程安全与耐久教育部重点实验室，北京 100084；2. 沈阳建筑大学 沈阳 110168
Unit_EngLish:1．Key Laboratory of Civil Engineering Safety and Durability of Ministry of Education of China, Tsinghua University, Beijing 100084, China
2．Shenyang Construction University, Shenyang 110168, China
Abstract_Chinese:Q235B和Q345B钢材在中国建筑领域应用广泛, 但却缺乏该类钢材的微孔扩张模型(VGM)和应力修正临界应变(SMCS)模型等微观损伤模型韧性参数, 且关于断裂方面的研究缺乏监测到钢材断裂时刻的应力与应变, 而无法正确对韧性参数进行校正．笔者取材自母材、热影响区、焊缝区的3种Q235B和Q345B钢材, 加工了36个缺口圆棒试件, 通过系列单轴拉伸实验, 获得了Q235B和Q345B钢材的VGM和SMCS模型韧性参数, 然后利用有限元计算VGM模型和SMCS模型对Q235B和Q345B钢材韧性断裂的预测效果．结果表明：VGM模型和SMCS模型对Q235B钢材破坏荷载的预测程度可以控制在25% 以内, 对Q345B钢材的预测可以控制在10% 以内, 两种模型对破坏荷载的预测程度精准于对破坏位移的预测程度．
Abstract_English:The Q235B and Q345B steels are widely used in Chinese building industry，but there is a lack of the vacancy growth model(VGM)and the stress modified critical strain(SMCS) model of such steels. The lack of monitoring of stress and strain at the moment of fracture in steel does not allow the correct calibration of toughness parameters. For this purpose，3 types of Q235B and Q345B steels were selected from parent metal，heat affected zone and weld zone，36 notched round bar specimens were processed，and VGM and SMCS model toughness parameters of Q235B and Q345B steels were obtained through a series of uniaxial tensile tests，and then used the finite element to calculate VGM model and SMCS model of Q235B and Q345B steel ductile fracture prediction effect. The results show that the prediction of failure load of Q235B steel by VGM and SMCS models can be controlled within 25%，and the prediction of Q345B steel can be controlled within 10% . The prediction of damage load by the two models is more accurate than the prediction of failure displacement.
Keyword_Chinese:Q235B; Q345B; VGM模型; SMCS模型; 韧性参数
Keywords_English:Q235B; Q345B; VGM model; SMCS model; toughness parameters

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