Stress Singularities at the Frictional Contact Interface Edge with Small Slipping

Abstract

Frictional contact interface edge appears in the fretting pair of a mechanical structure, and reduces its fatigue life. Due to the frictional force on the contact interface, the singular behavior at the edge is different from that of a bonded wedge, and is also different from that obtained by Hertz theory for elastic contact problems. In this paper, the singular stress field at a frictional contact interface edge is deduced theoretically. Based on the eigenequation which determines the singular order, the optimum geometry of the contact pad is discussed. Numerical analysis by using the boundary element method is also carried out to verify the theoretical results. It is found that the singularity depends not only on the material combination and the geometry shape of the frictional interface edge, but also on the coefficient of friction. Moreover, the singularity can be even stronger than 1/√r.