John Patrick Dowell

A Method to Predict Fretting in Diesel Engine Connecting Rod Bearing Bores

The highly dynamic nature of the loads imposed by the rotating and reciprocating components of diesel engines makes this machine highly susceptible to fretting fatigue problems. The authors have developed a method to predict the potential for fretting damage between the connecting rod and its big-end bearing shells. This method uses the ABAQUS finite element software package to conduct detailed contact analysis at the interface between the bearing shells and the connecting rod under the applied loads of the engine operating cycle. This analysis can be performed at the design stage, given the geometry of the connecting rod assembly and the data necessary to calculate the loads. Experimental measurements of the coefficient of friction between the bearing shell and the connecting road are presented, since this is an important factor in the contact analysis. Correlations of the predicted fretting damage to observed fretting locations from engine operation are presented for two variants of connecting rod design. As with any design analysis method, caution must be exercised in the application of the technique to new cases and in the interpretation of the results.Copyright