Nonlinear Analysis and Assessment for a Repairing Weld of Surge Line

摘要

A NPP unit surge line with a backslope is still not at the required design level after havingrnbeen installed. The installer adopted a repairing technology that is shown as following: twornwelds located at the ends of surge line were successively excavated, and welded again underrnthe surge line erection with the help of jacks in order to correct the surge line level in terms ofrnthe welding shrinkage force. After that, a stress analysis and assessment are required for thernrepairing technology. This paper describe the stress analysis, which includes: elastic stressrnanalysis with the piping system, elasto-plastic stress FEM analysis during lifting stage, andrnelasto-plastic FEM simulation of the welding shrinkage stress.