摘要
螺栓球钢网架结构火灾后,其螺栓球节点用高强度螺栓剩余力学性能对结构整体安全至关重要。通过对螺栓球钢网架常用的10.9 s级40Cr和35CrMn螺栓球节点用高强度螺栓进行过火冷却后力学性能试验,主要控制参数为过火温度和冷却方式,并对其力学性能变化规律进行了分析,得到两种高强螺栓过火冷却后的抗拉强度变化规律。结果表明:40Cr螺栓和35CrMn螺栓的过火温度分别低于500℃和400℃时,过火温度及冷却方式对高强螺栓的力学性能影响不大;40Cr螺栓过火温度在500~800℃,35CrMn螺栓过火温度在400~800℃时,过火温度对高强螺栓的力学性能有较大影响,而冷却方式仅对伸长率影响显著;过火温度大于800℃时,冷却方式对高强螺栓的力学性能影响较大。过火温度不大于800℃时,螺栓抗拉强度可按文中拟合公式进行计算,对于40Cr高强螺栓计算公式最大误差为3.78%;对于35CrMn高强螺栓,计算公式最大误差为6.79%。
After a fire,the residual mechanical properties of high strength bolts of bolt ball joints are very important to the overall safety of the structure.The mechanical properties of 40 Cr and 35 CrMn high strength bolts of 10.9 s grade commonly used in grid structures were tested after fire.The main control parameters in this experiment were the fire temperature and the cooling mode,whose effects on the mechanical properties were analyzed.It is shown from the results that when the fire temperatures of 40 Cr bolt and 35 CrMn bolt are lower than 500℃and 400℃,respectively,the fire temperature and cooling mode have little influence on the mechanical properties of high strength bolts.when the fire temperature of 40 Cr bolt is between 500℃and 800℃,or the fire temperature of 35 CrMn bolt is between 400℃and 800℃,the fire temperature has a great effect on the mechanical properties of high strength bolts,while the cooling mode only has a significant effect on the elongation.The cooling mode has a great effect on the mechanical properties of high strength bolts when the fire temperature is more than 800℃.The tensile strength of bolts can be calculated according to the fitting formulas proposed in this paper when the fire temperature is no more than 800℃.When the over fire temperature is less than 800℃,the tensile strength of bolts under different cooling methods can be calculated according to the formula in this paper.The maximum error of the formula is 3.78%for 40 Cr bolt and 6.79%for 35 CrMn bolt.
作者
冯绍攀
幸坤涛
王新泉
辛雷
肖树豪
FENG Shaopan;XING Kuntao;WANG Xinquan;XIN Lei;XIAO Shuhao(Central Research Institute of Building and Construction Co.,Ltd.,MCC Group,Beijing 100088,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2021年第2期198-205,共8页
Journal of Building Structures
基金
“十三五”国家重点研发计划(2016YFC0701306)。
