Detection of Bearing Damage using Elasticity Surface Wave
Yasuo INOUE, Hiroshi SAKAMOTO, Hideshi KAKISHIMA
With the bearing used on axle of Shinkansen train and the #6206 bearing put
to a fatigue test, the V(z) curves are measured by ultrasonic microscope.
Discussions are made about detection of bearing damage in terms of residual
stress, half-value breadth, comparing results of hardness test and metallographic
observation.
We have been able to conclude the following:
(1) The variation in sound velocity under elasticity surface wave as measured V(z)
curve is able to be applied for estimation of bearing damage due to fatigue.
(2) If metallography is normal, the sound velocity under elasticity surface wave
will correspond to the variations in residual stress and half-value breadth very
well. But when thermal deformation and big stress develop, the sound velocity
under elasticity surface wave will be lowered regardless of existing residual stress.