Dissipated energy-based fatigue lifetime calculation under multiaxial plastic thermo-mechanical loading

Abstract

The paper concerns the metallic material lifetime calculation under arbitrary multiaxial thermo-mechanical fatigue loading. An energy-based damage operator approach ( $\mathrm{eDOA}$ ) is introduced. In such an approach, fatigue lifetime is continuously computed by the Prandtl type damage operator. The dissipated energy of plastic deformation is applied as a damage parameter that is obtained at any moment by the recently developed multiaxial energy operator approach. Strain-life curves are transformed into energy-cycle damage curves in order to associate the damage parameter with the fatigue lifetime. The present approach is validated on turbocharger housing. A satisfactory evaluation of the fatigue lifetime is obtained even though visco-plasticity and mean stress correction are not addressed yet.