钢箱梁面板与U肋焊接残余应力的分布特性

Distribution Characteristics of Welding Residual Stress at U Deck-to-Rib Connection Detail of Steel Box Girder

为研究残余应力场对钢箱梁疲劳性能影响效应,以港珠澳大桥正交异性钢桥面板为例,采用数值模拟的方法,研究了正交异性钢桥面板焊接全过程及残余应力分布特性,分析了板件参数对残余应力的影响效应,得到钢箱梁确定正交异性钢桥面板焊接残余应力分布的经验公式.研究结果表明:采用ANSYS热-结构弱耦合数值模拟方法可反映实际焊接过程中残余应力场的分布;焊缝区域残余应力峰值受板件参数影响较小,横向最大残余应力约为300 MPa;沿板厚方向焊接残余应力符合正弦分布,表明采用正弦函数作为其经验分布模型是可行的.

This study aimed to research the influence of residual stress on fatigue resistance at the deck-to-rib weld joint of steel box girder. Research on distribution characteristics of the field of residual stress is a precondition to verifying the influence on fatigue resistance. The study was conducted taking Hong Kong Zhuhai Macao Bridge as an example to simulate the entire welding process and the distribution of residual stress. The influence of panel thickness on residual stress was analysed.Then,empirical formulae for the residual stress distribution were proposed. The results indicate that the variation of residual stress fields can be simulated accurately using numerical methods,i. e.ANSYS thermal-structural analysis. The panel thickness has little influence on the peak residual stress at the local weld zone,and the peak transverse residual stress is approximately 300 MPa. The residual stress distribution across the thickness of the deck is in good agreement with the sinusoidal distribution,which implies that considering sine function as the empirical distribution model is feasible.