Experimental observations of HFMI treated joints subjected to high R-ratios and Variable amplitude loading
2013 (English)In: Proceedings of the 66th IIW Annual Assembly and International Conference,Essen - GERMANY,11-17th September 2013, International institute of welding , 2013Conference paper (Other academic)
High frequency mechanical impact (HFMI) is a post-weld treatment method for improving fatigue strength of welded joints. The beneficial effect of this method is mainly based on compressive residual stresses created at the weld toe. The use of HFMI is becoming increasingly popular as the treatment is user-friendly and produces a uniform treatment region with good repeatability. Much of the experimental research on fatigue performance of HFMI treated welded joints has concentrated on compressive residual stresses created by the treatment and the fatigue strength of these joints under constant amplitude loading and relatively low mean stresses. This means that whilst beneficial compressive residual stresses are very well known, the stability of these stresses is less clear, as residual stress relaxation rate depends on the global and local welding geometry, type of loading, material condition, initial residual stress state and mean stress. Conditions with high mean stresses and individual large stress cycles are especially important, as in these cases, the maximum stress can be close to the yield strength of the material and stress relaxation might occur. New mean stress and variable amplitude fatigue data are presented and evaluated with respect to a proposed International Institute of Welding (IIW) design guideline concerning HFMI treated welded joints.
Place, publisher, year, edition, pages
International institute of welding , 2013.
High frequency mechanical impact (HFMI); Fatigue, Stress relaxation, Mean stress, Variable amplitude loading
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-137309OAI: oai:DiVA.org:kth-137309DiVA: diva2:678693
66th IIW Annual Assembly and International Conference,Essen - GERMANY,11-17th September 2013
QC 201401032013-12-122013-12-122014-01-03Bibliographically approved