钢桁腹-混凝土组合箱梁外接式节点疲劳性能试验研究
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中图分类号：U443.35 文献标志码：A 文章编号：2096-6717（2025）04-0100-09
Experimental study on fatigue performance of external joints in steel truss web-concrete composite box girders
TAN Yingliang，ZHU Bing，CUI Shengai，BI Xinyu， ZHANG Zhen，LU Baojie （School of Civil Engineering，Southwest Jiaotong University， Chengdu 6loo3l，P.R. China）
Abstract： Two joint models with a scale of 1：3 were fabricated and fatigue tests were carried out to investigate thefatigue performance of steltrussweb-concrete composite external joints and verify the reliabilityof the new structure applied to high-speed railway bridges.The fatigue damage mode，load-displacement relationship，and load-strain curve of the composite external joints were investigated，the fatigue force characteristics of the external joints under different stress amplitudes were examined and the experimental results showed that the fatigue life of the composite external joint exceeds 2.51 millon loading cycles under the design stress amplitude， the joint is not damaged，the stiffess is not reduced，and the fatigue resistance performance meets the requirements.Under the action of 1.4 times design stress amplitude，the measured fatigue life of the external joint is1.4 milion times.The fatigue damage mode of the external joint is the cracking of the exposed gusset plate on the tensile side，and the critical detail of composite external joint is the welding detail which connecting the exposed gusset plate and the stifening plate.The fatigue crack causes the stress redistribution in the gusset plate，the strain in the gusset plate above and below the crack is reduced by 81% at most，and the strain in the gusset plate near the crack is increased by 33% at most. According to the S-N curve obtained by the one-point method，the fatigue life of the composite external joint corresponding to the design stress amplitude of 53.2MPa （204号 is 4.36 million times，which is 2.18 times of the design value.
Keywords： steel truss web-concrete composite bridge；composite external joint；model test；fatigue perfor mance; fatigue damage
钢-混凝土组合结构桥充分结合了钢材和混凝土的优势，具有优良的整体受力性能，得到了广泛应用[1-4]。（剩余13496字）
