Mechanical failure analysis of automobile crankshafts under service reconditioned modelling approach

Mechanical failure of automotive crankshaft is modelled under varying service reconditioning. Primary factors (torsional vibration, bending vibration and twisting) and secondary factors (lubricity of engine, oil quality, and lubrication effectiveness) responsible for failures were identified. The stated factors were modelled using service life of main journal bearings at varying operation speeds as the crankshaft failure predictors under different reconditioning. Modelling was carried out based on standard relationships among the stated factors. The system model was implemented using experimental data from the selected vehicular crankshafts. The results showed that the service life (failure) time of the crankshafts were dissimilar. Unequal useful life of the crankshafts was attributed to variation in torsional vibration and lubricity. The findings will serve as guides for selecting right vehicular crankshaft(s) based on targeted useful life and reconditioning limits.