Welding residual stresses and their relaxation under cyclic loading in welded S550 steel plates

Abstract

This paper presents experimental and numerical investigations to determine the surface and through-thickness welding residual stresses and their relaxation in butt-welded plates under fatigue actions. The X-ray diffraction measurement validates the accuracy of thermal–mechanical analyses in estimating the as-welded residual stresses and their relaxation under cyclic loading. The experimental findings reveal that the relaxation of residual stresses occurs mostly within the first loading cycle. The amount of relaxation depends on the plastic deformation incurred, and hence the maximum load of the cyclic loads. The residual stress and its relaxation affect the stress ratio without changing the cyclic stress range.