A combined experimental and numerical approach was applied to develop a basic understanding of the fatigue damage process
taking place at edges exposed to cyclic mechanical loads.
A recently developed cyclic edge-loading test was used in order to simulate the fatigue loading of the edges of manufacturing tools and
to study the microscopic damage mechanisms. Accompanying finite element calculations were performed to provide a better understanding
of the loading conditions at edges subjected to cyclic mechanical loads. A comparison of the numerical simulation with the experimental
results revealed good accordance.
Main results of the investigations are the distribution of plastic strains and their evolution with increasing number of cycles, the distribution
of the residual stresses, the localisation and the evolution of damage at the microscale (microcracks and voids), and the localisation and
growth of fatigue cracks.
Micro-damage develops in the entire plastically deformed region. Fatigue crack nucleation was mainly found in deformation bands and
fatigue crack growth was only observed near the transition region between the extensively and the slightly plastically deformed zone not at
the loaded area but at the side area. The reason for that phenomenon is the formation of tensile residual stresses in this region which is
favouring fatigue crack growth.