Experimental investigation on the influence of welding residual stresses on fatigue for two different weld geometries
Nils Friedrich
Abstract
Abstract Fatigue tests on welded small‐scale specimens often do not show a distinct residual stress influence. An exception is longitudinal stiffeners, which are therefore frequently used to study the influence of welding residual stresses on fatigue. The results are not directly transferable to other weld geometries because the residual stress distribution depends on the weld geometries. In the presented investigation, fatigue tests on multilayer K‐butt weld and longitudinal stiffener specimens were performed. The tests were carried out in the as‐welded and stress‐relieved conditions at different load ratios. Initiation of macroscopic cracks was detected using digital image correlation. This allowed determining the influence of welding residual stresses on the initiation of macroscopic cracks, crack propagation and total fatigue life for both investigated weld geometries.