| 摘要: |
| Q235B钢材在中国建筑领域应用广泛，但目前却缺乏该类钢材的空穴增长模型（VGM模型）和应力修正临界应变模型（SMCS模型）等微观损伤模型韧性参数.为此，取材自热轧无缝钢管以及冷焊钢管母材、热影响区、焊缝区的4种Q235B钢材，加工了8个光滑圆棒试件和24个缺口圆棒试件，通过系列单轴拉伸试验，辅以数值分析及电镜扫描试验，获得了Q235B钢材的VGM和SMCS模型韧性参数，确定了Q235B钢材的特征长度，然后试验验证VGM和SMCS模型对Q235B钢材韧性断裂的预测效果.结果表明:VGM与SMCS模型对Q235B钢材韧性断裂预测效果均很理想. |
| 关键词: 韧性参数 特征长度 母材 热影响区 焊缝区 |
| DOI：103969/jissn1007 9629201502008 |
| 分类号: |
| 基金项目:国家自然科学基金面上项目（51278036）；中国铁路总公司科技研发计划项目(2013T002 A 2)；教育部高等学校学科创新引智计划项目（B13002） |
|
| Calibrations of Toughness Parameters of Microscopic Damage Model for Steel Q235B |
|
XING Jihui1, GUO Changlan1, ZHANG Pei2, YANG Qingshan1
|
|
1.School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China;2.China Light Industry International Engineering Company, Beijing 100026, China
|
| Abstract: |
| Steel Q235B is one of the most widely used structure steels in China. There are as yet no toughness parameters of void growth model(VGM model) and stress modified critical strain model(SMCS model) for such a popular material. Taking 4 types of steel Q235B materials extracted from the hot rolled seamless pipe and the matrix, heat affected zone as well as welded zone of cold welding pipe, eight smooth round coupons and twenty four notched round coupons were prepared. A series of uniaxial tensile tests were carried out, and finite element analyses as well as scanning electron microscopic tests were done too. Toughness parameters of VGM model and SMCS model for steel Q235B had been acquired, the characteristic length of steel Q235B was confirm. Experimental verification was made for the predict effect of ductile fracture of steel Q235B by VGM model and SMCS model. Research result shows that both VGM model and SMCS model can accurately predict the ductile fracture of steel Q235B. |
| Key words: toughness parameter characteristic length matrix heat affected zone welded zone |
