疲劳荷载作用后钢-混凝土组合外接式节点静载性能试验研究  

Experimental study on the static load performance of steel-concrete composite external joints after fatigue loading

作　　者：谭映梁 祝兵[1] 崔圣爱[1] Tan Yingliang;Zhu Bing;Cui Shengai(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,成都610031

出　　处：《Journal of Southeast University(English Edition)》2023年第3期269-276,共8页东南大学学报（英文版）

基　　金：The National Natural Science Foundation of China(No.U1834207)。

摘　　要：为研究疲劳荷载对钢桁腹-混凝土组合外接式节点静力性能的影响,设计并制作了3个1∶3节点模型,分别进行了静载破坏试验和疲劳后静载破坏试验,获得了节点破坏模式、荷载-位移曲线及节点板荷载-应变曲线,研究了节点屈服荷载、极限荷载、节点刚度及延性系数等力学性能指标的变化.试验结果表明:节点板是组合节点受力关键构件,节点板破坏是外接式节点的典型破坏模式;疲劳荷载对节点屈服前的受力性能影响较小,但对节点屈服后的受力性能影响显著;与仅承受静载的试件相比,未疲劳破坏试件的极限承载力减小4%,延性系数减小28%,有疲劳破坏试件的极限承载力减小25%,延性系数减小52%;疲劳裂纹引起了节点板应力重分布,增大了无疲劳裂纹区域的应变,且应变增长率随着与疲劳裂纹距离的增加而减小.To study the effect of fatigue loading on the static performance of the external joint of the steel truss web-concrete composite(STWCC)structure,three joint models were designed and constructed with a scale ratio of 1∶3.The failure mode and load-displacement curve of the joint were obtained through static load testing and post-fatigue static load testing.The load-strain curve of the gusset plate was plotted.The changes in mechanical performance indexes,such as the yield load,ultimate load,rigidity,and ductility coefficient of the joint,were comprehensively analyzed.The results showed that the gusset plate was the key load-bearing component of the STWCC joint,and gusset plate failure was the typical failure mode of the external joint.Although fatigue load had a minor impact on the mechanical performance of the joint before yielding,it exerted a remarkable impact post yielding.Compared with the specimen subjected to only static loading,the specimen without fatigue failure exhibited a 4%lower ultimate bearing capacity and a 28%lower ductility coefficient,while the specimen with fatigue failure exhibited a 25%lower ultimate bearing capacity and a 52%lower ductility coefficient.Fatigue cracks induced stress redistribution in the gusset plate and increased the strain in the regions without fatigue cracks.The strain increase rate decreased with increasing distance from the fatigue cracks.

关 键 词：钢桁腹-混凝土组合结构 组合外接式节点 模型试验 疲劳后静载 受力性能 

分 类 号：U24[交通运输工程—道路与铁道工程]