Vibration and wear prediction analysis of IC engine bearings by numerical simulation

Direct measurement of wear in IC engine bearings is a tedious activity. Vibration signals are known to carry substantial information about engine condition and correlate well with bearing clearance, but have not been well utilised for wear analysis. This paper presents a new method to simulate wear in IC engine bearings by integrating vibration and wear analysis techniques. Some unique features of the developed simulation are the inclusion of all three lubrication regimes (full-film, mixed and boundary) and the capability to update the wear profile and wear rates. The resulting increases in bearing clearance give rise to changing forces in the engine dynamic model, which feed back to the wear model. The peak forces are well detected using envelope analysis, which is used to process the vibration signals to reveal the location and strength of recurring impulses due to contact. The obtained wear critical zones and the impulse responses in the vibration signals are found to be in good agreement. The developed simulation can be effectively used for tracking wear related faults in engine bearings with reduced dependence on experimental work, used only to provide occasional model updates.