Elimination of Bowing Distortion in Welded Stiffeners

Abstract

Welding induces residual stresses in welded T-type stiffeners causing bowing (camber) distortion. Reducing the welding heat input or increasing the structural stiffness reduces or eliminates bowing distortion. However, where the structure geometry and weld size are fixed because of the design constraints, a transient differential heating process is effective in reducing bowing distortion. This paper presents an experimental verification and demonstration of transient differential heating for minimizing welding-induced bowing distortion in welded stiffeners. Conventional welding is carried out to demonstrate bowing distortion and establish a baseline case. Bowing distortion is eliminated using transient differential heating during welding using the same welding conditions. Residual stress measurements are taken using the blind hole drilling method, and a comparison of residual stresses for the baseline stiffener and for the stiffener with transient differential heating is presented.