管道环焊缝接头焊接残余应力预测

PREDICATION OF RESIDUAL WELDING STRESSES IN A GIRTH-BUTT WELDED PIPE

本文利用 ADINA非线性分析有限元程序 ,对低碳钢管道环焊缝接头焊接残余应力进行计算 .在热弹塑性有限元分析模型中考虑了材料热物理和力学性能依赖于温度变化 .计算预测结果表明 :在管道接头内表面焊缝中心及近缝区轴向和环向残余应力均为拉应力 ;随离开焊缝距离的增加 ,逐渐过渡为压应力 .在管道接头外表面焊缝中心处的轴向残余应力为压应力 ,而环向残余应力为拉应力 .计算预测值与实测值基本一致 。

In this paper,the residual welding stresses in a low carbon steel girth butt welded pipe are calculated with a nonlinear finite element code ADINA.The variation of thermal physical properties and mechanical properties of material with the change of temperature is taken into consideration in the thermal elastoplastic analysis.Calculated results show that the axial and the hoop residual stresses at the weld and in its vicinity on the inner surface of the pipes are both tensile.However, with the growth of distance from the weld,the stresses gradually turn into compressive.On the outer surface of the pipe,the axial residual stresses of the weld and in its vicinity are compressive while the hoop stresses keep tensile.The calculated results are in agreement with the experimental measurements,which shows that the finite element method (FEM) can be used to predict the residual welding stresses in a girth butt welded pipe both economically and effectively