Inherent Strain and Its Application for Prediction of Welding Deformation at Groove in Narrow Gap Welding

摘要

Welding deformation and welding residual stress are produced by the inherent strain which is created during the thermal cycle. If the inherent strain is known, both deformation and residual stress am be computed by simple elastic analysis. The magnitude and the distribution of the inherent strain depend mainly on highest temperature reached and the constraint. In case of narrow gap welding, the deformation at the groove is strongly influenced by constraint in various forms. Thus, the characteristics of the inherent strain in narrow gap welding are clarified from the aspect of constraint using the thermal-elastic-plastic FEM analysis in this report. Further, formulas to describe the inherent strain are proposed and apply them to the prediction welding deformations.