Near threshold fatigue crack growth in aluminium alloys at low and ultrasonic frequency: Influences of specimen thickness, strain rate, slip behaviour and air humidity

Different methods and procedures exist for the computation of the structural hot-spot stress at welded joints. These are either based on the extrapolation of stresses at certain reference points on the plate surface (or edge) close to the weld toe—as known from experimental investigations—or on the linearization of stresses in the through-thickness direction. Procedures for the application of both methods to finite element analysis have recently been proposed in the literature. In the present paper, the different methods are reviewed and applied to four different details in order to compare the methods with each other and to illustrate the differences. Conclusions are drawn with respect to their accuracy and sensitivity to finite element meshing.