Influence of technological residual stresses on the fatigue strength of machine parts

The durability and fatigue strength of machine components are critically influenced by the condition of their surface layer, which is formed during final mechanical processing. Residual stresses, work hardening, and surface roughness determine the load-bearing capacity under cyclic loading. Compressive residual stresses increase the endurance limit, whereas tensile residual stresses decrease it. Analytical models allow quantifying the relative change in the fatigue limit solely due to residual stresses. The presented approach integrates both the plane and complex stress states, providing predictive capability for component performance. These methods are applicable for the design and optimization of engineering components subjected to variable operational stresses.