We studied a new and simplified method for estimation of residual stress in a welded structure using inherent strain. Using this method, welding residual stresses can be calculated by elastic analysis with the finite element method. Residual stress at the welded joint of a pipe penetrating a thick plate is obtained by this method, and compared with the results from direct measurement. Inherent strain at the welded pipe joint is assumed to be a simple distribution, and residual stress is elastically calculated. Inherent strain distribution is inferred from that of welded joints with simple shapes. The residual stress distribution from inherent strain analysis agrees well with the results of direct measurement of a mock-up specimen. The proposed method is useful to estimate simply welding residual stress in various three-dimensional structures.
