Abstract
We present a new and simplified method of estimating residual stress in welded structures using inherent strain. The method makes use of elastic analysis with the finite element method, and can be used to calculate the welding residual stress in three-dimensional structures. The method is used to efficiently compute the residual stress remaining in complex welded structures. The inherent strain distribution at a welded joint of a pipe penetrating the spherical head of a pressure vessel and a socket-welded pipe joint can be assumed to be present in a simple distribution, and the residual stress was calculated by elastic analysis. Inherent strain distributions were inferred from those of welded joints with simple shapes. The estimated residual stress distributions using these inferred inherent strains agree well with the results of measurements of a mock-up specimen. Welding residual stress in three-dimensional structures with complicated shape can be estimated by using the proposed method in this paper.
