Abstract
Fretting damage is a phenomenon occurring at contact interfaces by two contacting bodies, the in-situ or
direct observation in necessary to investigate the mechanism of the phenomenon and its process. In this paper, a
small specially designed piezoelectric fretting wear testing device was developed for the purpose. The fretting wear
tests were carried out under the Hertzian contact of steel ball and glass plate. The experimental results showed that the appearance of worn surfaces fretted annulus, spread with increasing number of cycle, and process of crack
initiation.
