Analytical model for angular distortion in multilayerwelding under constraints

Abstract

We propose an analytical model for the fast prediction of angular distortion that is caused by practical multilayer (or multi-pass) butt welding under constraints. To this end, the relationships between angular distortion, bead size, thickness, and degree of constraint are derived by analyzing the welding deformation mechanism and considering the bead-on-plate welding experimental results. Prediction curves are then obtained while considering the geometry of the butt welding joint. We verify the formulas through experiments under various constraint conditions, with different welding joint geometries, heat inputs, and thicknesses. The proposed model can not only predict angular distortion in butt joints of various shapes, but also allows for providing restraint methods and welding sequences for minimizing distortion.