Computer aided nondestructive evaluation method of welding residual stresses by removing reinforcement of weld (proposal of a new concept and its verification)

A new method (the bead flush method) is proposed to estimate welding residual stresses non-destructively. First, the reinforcement of the weld is removed. Then from released strains on the surface due to removal, eigenstrain distributions are estimated by an inverse analysis. Finally, residual stresses are determined by the finite element method (FEM) using estimated eigenstrains as boundary conditions. Numerical simulations were conducted to develop a sophisticated procedure. It is shown by numerical simulations that the proposed method gives reasonably good predictions of residual stress. Also, the validity of the proposed method was evaluated experimentally for a butt-welded plate joint. Based on this work, future problems to overcome are discussed.