The effect of thickness variation and pre-strain on the cornering fatigue life prediction of a DP600 steel wheel disc

Abstract Cornering fatigue test of an automotive wheel is one of the essential tests to ensure the structural integrity of a wheel disc. Forming operation of wheel disc introduces forming history such as thickness reduction, pre-strain, and mean residual stresses. In this work, a methodology is proposed to consider the factors affecting the cornering fatigue performance of DP600 automotive wheel disc. The cyclic elastic-plastic Finite Element (FE) simulations are performed using the Chaboche kinematic hardening model. Local stress-strain states of critical element evaluated from FE simulations and fatigue parameters obtained from symmetric strain and stress controlled tests are coupled to predict the cornering fatigue life. Maximum equivalent stress and stress triaxiality at the cup radius region indicates a possible site for fatigue crack initiation. The incorporation of thickness variation and pre-strain effect is found to be the two most significant parameters for the accurate estimation of cornering fatigue life and failure location of wheel disc.