Review and considerations on the fatigue assessment of welded joints using reference radii

It is shown, that with the current recommended FAT values non-conservative results may occur if an assessment of weld toe failure is performed with notch stress approaches using maximum stresses and radii smaller r=1.0mm. To overcome this limitation, FAT-values in relation to the notch radii and notch opening angle are proposed. Another possibility to overcome this discrepancy is the use of effective stresses. With this approach the stress gradients in the notch ligament are evaluated and only one FAT-class independent on the radius on opening angle is necessary.