RHEOLOGICAL MODELS FOR STICK-SLIP BEHAVIOR

Stick-slip is a complex phenomenon which has been studied by researche rs front many points of view. A variety of engineering factors, such a s surface roughness, may contribute to this behavior. However, recent studies from basic science have shown that molecularly smooth surfaces separated by a film also exhibit stick-slip. Thus, the process may be intrinsically film-induced due to transitions between solidlike and f luid-like behavior. The authors of such studies often state that this kind of response indicates the futility of trying to describe such beh avior from a continuum perspective. A propose of this paper is to refu te that point of view. Other studies, both experimental and theoretica l, have indicated that continuum rheological models may be valid for f ilms of molecular (nanometer) scale. Various rheological models which can predict stick-slip are proposed in this paper, Calculated results are similar to those of experiment.