| 引用本文: | 强旭红,武念铎,姜旭,罗永峰.高强钢S460和S690火灾后力学性能试验[J].哈尔滨工业大学学报,2017,49(2):130.DOI:10.11918/j.issn.0367-6234.2017.02.021 |
| QIANG Xuhong,WU Nianduo,JIANG Xu,LUO Yongfeng.Mechanical properties of high strength steels S460 and S690 after fire[J].Journal of Harbin Institute of Technology,2017,49(2):130.DOI:10.11918/j.issn.0367-6234.2017.02.021 |
|
| 摘要: |
| 火灾后，材料力学性能的退化是导致钢结构火灾后承载力降低的主要因素.通过试验研究高强钢S460和S690过火冷却至常温后的力学性能，得到过火高温对高强钢S460和S690的弹性模量、屈服强度、极限强度及应力-应变曲线的影响规律，并与普通钢火灾后力学性能进行对比.结果表明，当过火温度低于600 ℃时，S460和S690冷却后可恢复其基本力学性能；当过火温度超过600 ℃后，甚至高达1 000 ℃时，高强钢S460仍可恢复其常温下75%以上的力学性能，而S690仅可恢复其常温下64.5%的弹性模量、38.1%的屈服强度及57.3%的极限强度；高强钢火灾后力学性能与普通钢不同.通过对试验数据进行数值拟合，给出可准确表达S460和S690火灾后力学性能剩余程度的预测公式，可用于指导含高强钢S460和S690构件的钢结构火灾后检测与鉴定，并为相关规范的修订提供参考依据.
|
| 关键词: 高强钢 火灾后 力学性能 剩余系数 预测公式 |
| DOI：10.11918/j.issn.0367-6234.2017.02.021 |
| 分类号:TU391 |
| 文献标识码:A |
| 基金项目:国家自然科学基金(51408150);中央高校基本科研业务费专项资金(2014KJ044) |
|
| Mechanical properties of high strength steels S460 and S690 after fire |
|
QIANG Xuhong, WU Nianduo, JIANG Xu, LUO Yongfeng
|
|
(College of Civil Engineering,Tongji University, Shanghai 200092, China)
|
| Abstract: |
| The load bearing capacity of steel structures after fire reduces mainly due to the deterioration of its mechanical properties. This paper presented an experimental study on material properties of high strength steels S460 and S690 after fire. The post-fire elastic modulus, yield and ultimate strengths, ductility and stress-strain curves were obtained and compared with the post-fire mechanical properties of mild strength steels. It is found that when the fire temperature from which the high strength steel is cooled down is less than or equal to 600 ℃, S460 and S690 can regain their original mechanical properties. When the fire temperature is up 1 000 ℃, S460 can also regain more than 75% of its original mechanical properties, but S690 only regains 64.5% of its original elastic modulus, 38.1% of its original yield strength and 57.3% of its original ultimate strength. The mechanical properties of high strength steels are different from mild strength steels. Predictive equations were proposed to evaluate the post-fire material properties of S460 and S690. Comparing with the test results, the predictive equations were validated. The predictive equations can be employed for practical inspection and appraisal of steel structures after fire with members made of S460 and S690, and provide a reference for the revision of current worldwide leading design standards.
|
| Key words: high strength steel post-fire mechanical properties residual factor predictive equation |
