球罐焊接残余应力数值模拟分析

Numerical simulation analysis of welding residual stresses in spherical tank

利用有限元法动态模拟球罐环焊缝以及平板的焊接过程,分析了球罐焊接过程温度场的变化状况和焊接残余应力分布规律.结果表明,焊接热影响区范围很小,球罐环焊缝焊接残余应力是经向和径向坐标的函数,纬向焊接残余应力大于经向应力,两向应力的最大值均处在热影响区内,最大应力值超出了材料的屈服极限,是产生裂纹缺陷的原因之一等.用X射线衍射的方法测试了平板焊接接头的焊后残余应力,并将测试结果与有限元模拟计算结果比对,验证了模拟计算方法的可靠性和计算结果的正确性.

Using finite element methods to carry on a dynamic simulation of a welding process of spherical tank girth welds and the plate,from which the changes in the temperature field and the laws of welding residual stress distribution in the welding process of the spherical tank were analyzed.It was mainly concluded that welding heat-affected zone was very small,and the residual welding stress in spherical tank girth welds were functions of meridional and radial coordinate,and the zonal residual welding stress was larger than the meridional stress,and the maximum value of 2-D stress was in the heat-affected zone,and the value of the maximum stress exceeded the yield stress,which was a cause of the spherical tank defects.The residual welding stress in the plate welded joint was tested by X-ray method,and the testing results were compared with the numerical simulation results.The results matched which means the simulation method is feasible.