Numerical Modeling of Fatigue Damage and Fissure Propagation under Cyclic Loadings

The purpose of this work is to develop a numerical simulation procedure in order to predict the evolution of the fatigue damage and rupture in mechanical parts (such as rolling bearings and gears) under cyclic loadings. The study of the fatigue damage evolution, from the first defect appearance until the part's failure, is primordial in view of the preventive maintenance. The numerical procedure is based on the continuum damage mechanics and the thermodynamics of irreversible processes. The damage effects are fully coupled with the elasto-plastic constitutive laws on a macroscopic point of view. The Sines fatigue criterion for multiaxial stress states is used to estimate the lifetime of mechanical parts in terms of number of cycles. This numerical model is implemented into Abaqus/Explicit using an user's subroutine (Vumat). A cycle jumping algorithm allows to largely reduce the computation time. Some remeshing techniques are used to follow up the damage and rupture evolutions. The birth and the growth of the damage and rupture can be visualized via the element deleting and remeshing. These numerical tools are applied to a 2D specimen under a cyclic stretching.