Modelling Acoustic Emissions induced by dynamic fluid-asperity shearing in hydrodynamic lubrication regime

Abstract This paper investigates the mechanism and characteristics of Acoustic Emission (AE) generated from the dynamic Fluid-Asperities Shearing (FAS) in the hydrodynamic lubrication (HL) regime. Firstly, a FAS model is derived to take into account the dynamic effect of surface asperities. Then, the influence of surface profiles, lubricants and operating conditions are illustrated on AE characteristics, i.e. magnitudes and frequency bandwidths. It has been found that the correlation length of surface roughness parameters and shear rate are two main factors affecting FAS behaviours and consequently AE characteristics. Finally, the corresponding experiments are carried out based on a rheometer rig, which validate the predictability of the model and new findings, paving the foundation for developing AE based monitoring techniques.