ANALYSIS OF PAD COMPLIANCE UNDER FRETTING FATIGUE
fretting fatigue, life estimation, pad deformation
Fretting fatigue is a contact problem of great importance to the aerospace industry. Along the
years, a series of experimental campaigns have been carried out, however, not many of them carried
about the deformation from the pad and how it could impact the life estimates. One of the reasons
for not much effort being put into the deformation effect is that the well known Cattaneo-Mindlin
and subsequent analytical solutions for the contact between two cylinders do not account for lateral
deformation of any cylinder. In this study, the pad deformation variation was put into focus by
systematically estimating the fretting fatigue lives for different pad overhangs, i.e. the distance
between the contact surface and the apparatus that holds the pad. The same variation of pad
overhang was carried in experimental tests with Al 7075-T651 alloy. The estimates were taken using
finite element analysis and theory of critical distances. They represented well the trend that with the
increase of the pad deformation the fretting fatigue life decreases. Estimates with the undeformable
analytical solution can significantly over-estimate the lives up to 37\%. The proposed methodology
for estimating life have shown average errors of less than 18%.