Fatigue behaviour of automatically HFMI-treated welds

Abstract

Due to notches, welds are most critical regarding fatigue failure within cyclic loaded constructions. Therefore, various post-weld-treatment techniques like post-weld treatment by high-frequency mechanical impact (HFMI) treatment have been invented to improve the fatigue strength of welded details. The benefit, resulting from HFMI treatment, has already been proven by numerous studies. Since a manual HFMI treatment must be performed by a skilled and trained person to ensure an acceptable treatment quality, an automated application of HFMI treatment is supposed to result in a more reliable and consistent treatment result, which does not depend on the operator. Furthermore, a robotic application of HFMI treatment enables an economic implementation of HFMI treatment of automated welded constructions like offshore wind energy converters and various mechanical components, as these parts do not have to be taken out of the production chain to manually perform HFMI treatment. This paper focuses on the experimental investigation of the fatigue behaviour of automated HFMI-treated welds, using a developed robotic application of the HiFIT device (specific HFMI tool).