不同热源模型下顶板-U肋焊缝焊接残余应力分析

Analysis of Welding Residual Stress at Deck-to-rib Welded Joint under Different Heat Source Models

钢桥面板在焊接过程中会产生较大的残余应力,严重影响其使用性能。为确定焊接过程中残余应力的大小,基于有限元软件ANSYS,建立了正交异性钢桥面板U肋节段模型,采用均匀体热源模型、半球状热源模型、双椭球热源模型三种不同的热源模型,通过生死单元技术,对顶板-U肋焊缝焊接过程进行了数值模拟,得到了不同热源模型下的焊接温度场。在温度场计算结果的基础上,采用间接耦合法,计算了各热源模型下的焊接应力场。对不同热源模型下的温度场和应力场计算结果进行了比较。结果表明:三种模型在温度场整体分布和应力场顺桥向与横桥向分布上基本一致,仅在纵向应力沿板厚分布上存在轻微差异。

Large residual stress is induced in the welding process of steel deck,which seriously affects its performance.To determine the residual stress,a U-rib model of an orthotropic steel deck was established by ANSYS.The welding process was respectively simulated by three different heat source models,homogeneous heat source model,hemispherical heat source model and double ellipsoidal heat source model.Through element birth and death technique,welding temperature fields under different heat source models were obtained.Indirect coupling method was then used to calculate the welding stress fields.The results showed that the temperature field and stress field distributions of the three models were basically the same in longitudinal and transverse directions of bridge,but there were some differences in longitudinal stress along plate thickness direction.