高强钢平齐式端板连接节点火灾后性能数值研究

Numerical Study on Postfire Behavior of High Strength Steel Flush Endplate Connections

摘要:

采用Abaqus软件对高强钢平齐式端板连接节点火灾后性能进行模拟，结果表明有限元模型能准确模拟节点的弯矩转角关系、节点失效模式和应力分布等.在此基础上，对端板采用Q460高强钢和Q345普通钢的节点进行参数分析.结果表明：在历经550 ℃火灾高温并冷却后，节点力学性能未发生明显退化；端板材料对节点初始刚度无影响,但对节点承载力影响显著；与采用较厚普通钢端板的节点相比，采用较薄高强钢端板的节点可实现相近的承载力甚至更高的转动能力.

关键词:高强钢; 平齐式端板连接节点; 火灾后; 结构火灾安全; 数值研究

Abstract:

The behavior of high strength steel flush endplate connections on postfire was simulated according to the test results using finite element software Abaqus. Comparison between the analysis results of finite element method (FEM) and all representative experimental results on momentrotation relationship, failure mode and stress distribution of flush endplate connections shows that good agreements exist. Based on above，parametric analysis on Q460 high strength steel endplate connections and Q345 mild steel endplate connections was conducted. Results show that: the degradation of mechanical behavior of the connections is not significant after cooling down from fire temperature 550 ℃; the material property of the endplate has no impact on the initial stiffness of the connections but has important impact on the bending capacity of the connections; a connection with thinner high strength steel endplate can achieve similar bending capacity and equivalent or even higher rotation capacity after fire in comparison with a connection with thicker mild steel endplate.

Key words:high strength steel; flush endplate connection; postfire; structural fire safety; numerical study