初始缺陷角度对钢桥面纵肋顶板焊缝应力强度因子影响分析

初始缺陷在钢桥面板工厂焊接加工时难以避免，是影响钢桥面疲劳性能的重要内在因素。为研究初始缺陷角度对纵肋顶板焊缝疲劳开裂的影响，建立了包含典型初始缺陷工况条件下的有限元模型，分析得到了裂纹前缘应力强度因子。计算结果表明：竖向初始缺陷状态下的裂纹扩展能力最强；初始缺陷从竖向偏转至45°过程中，偏转角越大，张开型应力强度因子越小，滑开型和撕开型应力强度因子越大。断裂参数数值计算方法与分析结果可为相关钢桥面构造抗疲劳分析提供参考。

Analysis on Influence of Initial Defect Angle on Stress Intensity Factor of Welded Joints of Longitudinal Rib Roof of Steel Bridge Deck

Initial defect is difficult to avoid during welding and processing of steel bridge deck in manufactory, which is an important internal factor influencing the fatigue performance of steel bridge deck. In order to analyze the effect of initial defect angle on the fatigue cracking of welded joints of longitudinal rib roof, a finite element model is established under the typical initial defect conditions to analyze and obtain the stress intensity factor at the front edge of cracks. The calculation results indicate that the crack propagation ability is the highest in the vertical initial defect state. During the initial defect deflection from vertical to 45°, the larger deflection angle, the smaller stress intensity factor of the opening mode, and the larger stress intensity factors of the sliding and tearing modes. The numerical calculation method and analysis results of fracture parameters can provide reference for the fatigue resistance analysis of steel bridge deck structures.