D. Pupaza et Jh. Beynon, THE USE OF VIBRATION MONITORING IN DETECTING THE INITIATION AND PREDICTION OF CORRUGATIONS IN ROLLING-SLIDING CONTACT WEAR, Wear, 177(2), 1994, pp. 175-183
Vibration displacements and accelerations have been monitored on a mod
ified Amsler machine during the dry rolling-sliding wear testing of ra
il steels. Certain combinations of contact stress and creepage lead to
periodic circumferential surface deformations of the test discs, term
ed corrugations. The low frequency corrugations are defined as facets.
Dramatic facets have occurred at 500 MPa maximum Hertzian contact str
ess and 10% creepage, in the frequency band ranging from 1-100 Hz, wit
h a typical facet frequency initiated at 58.25 Hz. No higher frequency
corrugations occurred during the test run, unlike previous tests (J.E
. Garnham, J.R. Brightling and J.H. Beynon, Wear, 124 (1988) 45-63).Th
e evolution of the surface deformation was observed by surface profilo
metry, as well as by monitoring the facet vibration component trend, a
nd a good correlation between the two has been found. Aslo, a signific
ant correlation between the predominant peaks of the displacement spec
tra and the higher harmonics of the rotation frequency have been detec
ted, leading to conclusions concerning the mechanism of facet initiati
on. At the end of the test the facets degenerated into pronounced ecce
ntricities causing a high level component of the rotation frequency th
at could easily be detected by following the evolution of the characte
ristic component. The tests highlighted that the vibration displacemen
t is more suitable for the monitoring of rolling-sliding contact defec
ts than is the acceleration, which tends to emphasise the high frequen
cy components. Vibration monitoring is shown to be a proper and powerf
ul tool for the early detection of facet initiation.