Computational analysis and characterization of fretting stress fields

If a friction pad is idealized as sharp corner contact, the stress around the corner can be hyper-singular, as predicted in many known works. In this paper we have investigated singular stress characterization of sharp friction pad based on finite element computations with varying pad radii. It is confirmed that the sharp pad possesses singular stress and the singularity depends on both friction coefficient and pad geometry. Our detailed computations confirm that the validity of the sharp pad solution is limited only for mathematically sharp corner. As soon as the pad corner is rounded with a small finite radius, the stress concentration decreases dramatically which cannot be approximated by the hyper-singular asymptotic solution. For a rounding radius larger than 0.1 mm, stress fields of the friction pair are described by the rounded contact surface. One may use the known stress intensity factors to assess the friction fretting damage.