Fatigue life predictions of spot welds using coarse FE meshes

TLDR: In this paper, a new engineering method for fatigue life prediction of spot welds is presented, which starts with a coarse finite element representation of each spot weld using shell elements and one beam element.

Abstract: A new engineering method for fatigue life prediction of spot welds is presented. The method starts with a coarse finite element representation of each spot weld using shell elements and one beam element. Forces and moments at the spot weld are calculated using the finite element method and used in an analytical calculation of the stresses around the spot weld. Mode I and II stress intensity factors are calculated from these stresses. Thereafter, an equivalent stress intensity factor is calculated and the fatigue life prediction is made using one unique ΔK-N curve for spot welds. Good agreement is found between a ΔK-N curve derived from the Paris law and several experimental results from the literature, although in order to achieve this, a shear correction factor is required. This factor is discussed in relation to results from the literature.