In the high cycle fatigue (HCF) regime, the fatigue strength of welded joints is influenced by residual stresses (RS) induced during welding processes. If the weld toe is modelled via a sharp V-notch, the distribution of weld toe residual stress can be shown to be asymptotic with a singularity which follows either the linear-elastic or elastic-plastic solution depending on parameters that range across material properties, specimen clamping conditions, and the welding process. For thicker plates, multipass welding is used instead of single-pass welding to reduce the heat input and hence the width of the fusion zone (FZ) and heat-affected zone (HAZ). However, for a fixed plate thickness, the magnitude and extent of residual stresses near the weld toe will vary according to the number of passes used in the welding operation. In this paper the influence of multipass welding on the residual stress field near the weld toe has been analysed using a combination of analytical and numerical techniques. It was found that the higher the number of weld passes, the higher the magnitude of the residual asymptotic stress field near the weld toe

Fatigue failure in hard oxide-coated aluminum is usually driven by rapid short crack propagation from the interface through the substrate; mitigation of this is possible by introducing interfacial compressive stresses. Combining cold work with hard oxide coating can improve their performance under conditions of simultaneous wear, corrosion, and fatigue. Three-dimensional strain fields in an aluminum alloy with combined cold work and PEO coating have been measured and mechanisms for stress redistribution presented. These comprise material consumption, expansive growth of oxide layers, and local annealing.

A growing fatigue crack gives rise to a plastically deformed wake of material that envelops the crack. In this work, the plastic wake extent during fatigue crack growth is experimentally quantified by analyzing the crack tip displacement fields measured with digital image correlation. A novel technique based on use of a yield criterion is proposed that uses the undamaged state of the specimen as the reference state in the image processing. The plastic wake was identified by differentiation of the residual displacement fields obtained with a near-zero load level to avoid any rigid body motion. The plastic wake extent was then found by assuming that the boundary between the elastic and plastic regions would occur when the equivalent stress was higher than the yield stress of the material. The results presented can contribute to a better understanding of the mechanisms driving fatigue crack propagation.