A Simplified Analysis of Residual Stress at Welded Joints between Plate and Penetrating Pipe

We present a new and simplified method of estimating residual stress in welded structures by using inherent strain. The method makes use of elastic analysis by means of the finite element method, and can be used to calculate the welding residual stress in three-dimensional structures. The method can be used to efficiently compute the residual stress remaining in complex welded structures. The inherent strain distribution at a welded joint of a small-diameter pipe penetrating a thick plate can be assumed to be present in a simple distribution, and the residual stress can be 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 strain gauge measurements of a mock-up specimen. The proposed method in this paper can estimate welding residual stress in three-dimensional structures of complicated shapes in a simple way.