Low cycle fatigue evaluation of welded structures with arbitrary stress-strain curve considering stress triaxiality effect

Abstract

In this work, load-controlled low-cycle fatigue tests of butt and lap joints are conducted, and a structural strain range parameter is proposed to characterize the fatigue behavior of weldment. A new scheme to calculate the structural strain range is formulated, which can deal with arbitrary material elastic–plastic behavior. The method captures the lateral structural constraint effect through the stress triaxiality parameter. The new fatigue parameter shows superior data transferability, which correlates high and low-cycle fatigue data of steel, aluminum, titanium, and magnesium weldments into one master E-N curve.