Fillet radius influence for keyway subjected to fatigue: An investigation on an actual application

The keyway is a widely employed solution to link a hub with a shaft. This paper underlines the importance of the fillet radius at the keyway base, highlights the combined effect between bending and torsion and verifies the stress concentra- tion factors present in the literature thanks to Finite Element Method. Starting from a first analytical analysis of the shaft, a series of FE analyses were carried out with the aim of understanding why certain shaft failures occurred. In these analy- ses, the key presence is considered and the torque is transmitted through it. The analysis reveals that standard verifica- tion could fail for some configurations and for the precise evaluation of the fatigue behaviour, for this reason a numerical model is always suggested.