In this work, an evaluation was made to prove the possibility of emplo
ying a neural net method for the classification of debris and monitori
ng of a lubricated contact pair. We trained a neural net to classify t
he severity of wear into two types from the morphological features of
the wear debris. The following procedures were used. First, the shape
of wear particles was characterized by Fourier descriptors. The Fourie
r descriptors were considered as coordinates of a point in multidimens
ional feature space. A set of points form a cluster, and the location
and structure of the cluster depend on the morphology of the wear part
icles and the current conditions of the contact system. A distance dis
tribution between the debris in the feature space was used to represen
t the location of the cluster. Second, we trained a back-propagation n
eural net. To train the neural net, we used the distance distribution
corresponding to the different stages of the wear process as an input
vector and encoded the wear rate as a desired response. The network wa
s then further trained until the desired error goal was achieved. Fina
lly, we tested the trained neural net. The ability of the neural net m
ethod to monitor wear is shown. (C) 1997 Elsevier Science S.A.