钢桥面板疲劳裂纹全寿命周期扩展特性

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中图分类号：U448.3 文献标志码：A 文章编号：2096-6717（2025）03-0180-10

Fatigue crack life cycle growth characteristics of steel bridge deck

LU Naiwei CUI Jian LUO Yuan WANG Honghao （1. School of Civil Engineering，Changsha Universityof Science& Technology，Changsha 41Ol14，P.R.China; 2.College of Civil Engineering，Hunan Universityof Technology，Zhuzhou 4l2Oo7，Hunan，P.R.China）

Abstract：The initial welding defect is the key factor that affects thefatigue performanceofthe structural details of the orthotropic steel bridge deck.In order to study the whole life cycle dynamic characteristics of crack initiation and propagation of the joint weld between the top plate and the longitudinal ribof theorthotropic steel bridge deck，based on the fracture mechanics theory and ABAQUS-FRANC3D interactive technology，the dynamiccharacteristics of the stress intensity factor in the whole process from the weld buried defect to the fatigue fracture were studied，the crack shape development law was revealed，and the influence of sensitive parameters on the crack growth rate and fatigue life wasanalyzed，the ful-life propagation behaviour of fatigue crack is clarified，and thereliabilityof theresearch results is verified bythe full-scale segmental fatigue testof steel bridge deck.The analysis results show that the fatigue crack growth behavior of steel bridge deck can be divided into three stages：burial stage，initiation stage，and propagation stage.The distribution of stress intensity factors in the buried initiation stage and the propagation stage along diferent crack paths are exactly opposite;buried cracks of any initial shape tend to be round with continuous expansion，and surface cracks of any shape gradually flatten，which reasonably explains the flat shape of surface cracks when they continue to extend to the roof; the crack propagation rate along the upper surface of the buried stage is 54% higher than that along the lower surface.The crack propagation rate from the buried initiation stage to the roofdirection is larger; The crack shape ratio and the burial depth have a great influence on the initiation life，and the initiation life accounts for the majority of the total fatigue life.

Keywords： steel bridge deck; fatigue crack; fatigue life；stress intensity factor;embedded crack

正交异性钢桥面板具有轻质高强、工厂化制作、施工便捷等优点[1-2，但由于钢桥面板焊缝较多，含大量焊接接头，容易在焊缝内部或表面产生初始裂纹及气孔、夹杂等焊接缺陷。（剩余13730字）