Abstract
From the viewpoint of monitoring and maintenance (especially condition-based maintenance) of machinery, it is extremely important to recognize and quantify friction and wear phenomena, such as the progress of wear and the state of friction at interfaces. An acoustic emission (AE) is intimately related to the deformation and fracture of materials and the AE-based method is useful in obtaining large quantities of information relating to friction and wear phenomena. Accordingly, the AE method, unlike other estimation methods in current use, permits direct estimations and is very effective for the in-process monitoring of the state of rubbing surfaces. For the recognition and quantification of friction and wear phenomena, it is necessary to elucidate the relationship between AE signals and friction and wear phenomena. However, little is known regarding the relationship between AE and friction and wear phenomena, because of the complexity of such phenomena. To mitigate the complexity, not only experiments by repeated rubbing (a typical experimental method), but also experiments with the simplified friction systems have been performed in this study. As a result, the features of the AE parameters and the AE frequencies were revealed for the quantitative evaluation of wear state.
