An interval-energy-based method for lifetime assessment of dissimilar lightweight metal welded joints

In consideration of uncertainties of material characteristics and its welding and forming process, an interval strain energy density method for predicting fatigue life of dissimilar lightweight metal welded joints was presented in this paper. Firstly, the mechanical performance parameters and fatigue properties of welded joints with parental material aluminum alloy 5083H111 and 5754 were obtained by experimental work. Based on the interval number approach, the interval relationship between the elastic and plastic strain energy density and fatigue life was constructed, including lower and upper interval bounds. Then, a finite element model of the dissimilar lightweight metal cross welded joint was generated to calculate the stress-strain response curve under cyclic loadings through the non-linear finite element analysis. The predicted lifetime and failure location for the cross welded joint based on the interval strain energy density method agreed well with the tested results.