陈桥, 姜健, 蔡文玉, 陈伟, 叶继红. 基于SMCS模型的高强螺栓及节点火灾全过程断裂性能模拟[J]. 工程力学, 2024, 41(2): 56-70, 159. DOI: 10.6052/j.issn.1000-4750.2022.03.0252
引用本文: 陈桥, 姜健, 蔡文玉, 陈伟, 叶继红. 基于SMCS模型的高强螺栓及节点火灾全过程断裂性能模拟[J]. 工程力学, 2024, 41(2): 56-70, 159. DOI: 10.6052/j.issn.1000-4750.2022.03.0252
CHEN Qiao, JIANG Jian, CAI Wen-yu, CHEN Wei, YE Ji-hong. SIMULATION ON FRACTURE PROPERTIES OF HIGH-STRENGTH BOLTS AND CONNECTIONS UNDER THE WHOLE PROCESS OF FIRE BASED ON SMCS MODEL[J]. Engineering Mechanics, 2024, 41(2): 56-70, 159. DOI: 10.6052/j.issn.1000-4750.2022.03.0252
Citation: CHEN Qiao, JIANG Jian, CAI Wen-yu, CHEN Wei, YE Ji-hong. SIMULATION ON FRACTURE PROPERTIES OF HIGH-STRENGTH BOLTS AND CONNECTIONS UNDER THE WHOLE PROCESS OF FIRE BASED ON SMCS MODEL[J]. Engineering Mechanics, 2024, 41(2): 56-70, 159. DOI: 10.6052/j.issn.1000-4750.2022.03.0252

基于SMCS模型的高强螺栓及节点火灾全过程断裂性能模拟

SIMULATION ON FRACTURE PROPERTIES OF HIGH-STRENGTH BOLTS AND CONNECTIONS UNDER THE WHOLE PROCESS OF FIRE BASED ON SMCS MODEL

  • 摘要: 高强螺栓广泛应用于钢结构节点连接,火灾高温会影响其基本材性和断裂行为,从而影响螺栓节点抗火性能甚至整体结构抗倒塌性能。基于10.9级高强螺栓火灾全过程(升温段、降温段、火灾后)单轴拉伸试验结果,结合有限元模拟,对不同温度历程和应力三轴度对应的螺栓SMCS断裂模型进行校准,并与螺栓材性试验和T-stub节点试验结果对比验证;对T-stub节点火灾全过程断裂行为进行参数分析,研究损伤准则和温度历程对节点失效模式和变形特征的影响。结果表明:校准的SMCS模型能够有效、准确地预测螺栓和节点在火灾全过程和高应力三轴度(0.3~1.2)下的受拉断裂行为,适用预测误差在12%以内;拉伸温度和峰值温度是影响高强螺栓抗断能力的主要因素,螺栓抗断能力随温度升高而提高;不同温度历程下T-stub节点可能发生翼缘板屈服断裂、翼缘板和螺栓同时屈服断裂、螺栓屈服断裂三种失效模式,且节点的变形能力(延性系数)与失效模式有关,确定钢板母材和螺栓的断裂模型是准确预测节点失效模式的关键。

     

    Abstract: High-strength bolts have been widely used in steel connections. The fire-induced high temperature will affect its basic material properties and fracture behavior and may affect the fire resistance of bolted connections and even the collapse resistance of the whole structure. Based on the uniaxial tensile tests under the whole process of fire (heating stage, cooling stage and after fire) and finite element simulation on high-strength bolts, the SMCS fracture model of Grade 10.9 high-strength bolts with different temperature conditions and stress triaxialities is calibrated and compared with the results of bolt material properties tests and T-stub connection test. Parametric studies are conducted on the fracture behavior of T-stub connections in the whole process of fire, and the effect of damage criterion and heating history on the failure mode and deformation characteristics of T-stub connections is studied. The results show that the calibrated SMCS model can effectively and accurately predict the tensile fracture behavior of bolts and connections in the whole process of fire and high stress triaxialities (0.3-1.2), and the prediction errors are less than 12%. The tensile temperature and peak temperature are the main factors affecting the fracture capacity of high-strength bolts. The fracture capacity of bolts increases with the increase of temperatures. Under different heating histories, T-stub connections may have three failure modes: yielding fracture of flange plate, simultaneous yielding fracture of flange plate and bolt, and yielding fracture of bolt. The deformation capacity (ductility index) of connections is related to the failure mode. Determining the fracture model of base metal and bolts is the crux to accurately predict the failure mode of connections.

     

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