Abstract: Residual stress of thick plate welding is affected by many factors and varied complicatedly. The research of residual stress distribution model is one of the difficult points in this field, so the actual distribution measurement is very important. Two plates with thickness of 100 mm are presented, which are made of A105 steel, subjected to multi-pass weld with submerged automatic arc welding technology. Then experimental measurement and MSC.Marc finite element simulation are combined to analyze the welding residual stress distribution of 100 mm special thick plate by multi-pass and multi-layer welding. Then, distribution curves of transverse residual stress and longitudinal residual stress on the top surface, and along the thick direction are given. The finite element calculations are coincided with the experimental results, indicating that the finite element model established is reasonable. In particular, the residual stressin the thick direction can be gained by the finite element result, which solves the problem about residual stress is inconvenient to measure in the thick direction and offers reference for the future residual stress research work.

Key words: Marc finite element simulation, Multi-pass and multi-layer welding, Special thick plate, Welding residual stress