On the assessment of train crankshafts fatigue life based on LCF tests and 2D-FE evaluation of J-integral

Abstract Low cycle fatigue (LCF) tests were carried out on forged carbon steel (AISI 4130) used in V12 Diesel engine crankshafts, at room temperature and 300 °C, under total strain control. These tests were performed in order to study the cyclic mechanical behavior, lifetime and damage mechanisms of the material. Then, a Chaboche nonlinear isotropic-kinematic hardening model available in the commercial FE code Abaqus was identified and a 2D-FE evaluation of J -integral, chosen as a crack driven force, has been carried out to estimate the crankshaft life under cyclic bending loads when a macroscopic crack propagates. It has been found that i ) material lifetime was not affected by temperature at the studied domain, ii ) the fractured surfaces examined with SEM exhibit typical features of ductile fracture behavior, and iii ) the number of cycles spent until the total crankshaft fracture is relatively short compared to its total fatigue life.