部分除去ビードフラッシュ法による３次元溶接残留応力の非破壊評価

抄録

One of the major concerns in the structural integrity of aged-welded structures is to evaluate residual stresses nondestructively. Residual stresses are generated by eigenstrains in thevicinity of weld bead. It means that eigenstrains are the source of residual stress generation. If eigenstrains are known experimentally, residual stresses can be estimated by a simple elastic FEM analysis. Based on this concept, authors have proposed a new method, the bead flush method. The purpose of the present study is to simplify the bead flush method by partially removing weld reinforcement. To improve accuracy of the conventional method, one of the regularization methods, SVD and L-curve are adopted to regularize the solution in the inverse analysis. The proposed partial removal method has following advantages comparing to the conventional one. The proposed method saves inspection times and costs because only a part of weld reinforcement is removed to measure the released strains. Secondly, residual stresses of structures at the same position can be evaluated periodically.