A Methodology Using Cycle Jump Algorithm for Prediction of the Low Cycle Fatigue Life Concerning Mechanical Structures

In this paper, a numerical methodology using cycle jump algorithm is developed to predict the low cycle fatigue residual life of mechanical structures subjected to initial state conditions. A fully coupled model that accounting for isotropic and two kinematic mixed hardening and coupling with fatigue damages are developed in order to accurately predict the residual fatigue life. Obviously, the time-based algorithms used for solving fatigue problems are confronted to the huge size of the CPU time needed. The cycle jump algorithm that adapt the jump according to evolution of the mechanical fields constitutes an alternative solution that avoids the calculation of the total loading cycles. The model parameters have been identified in the case of DP600 steel specimen subject to symmetric tension-compression loading path. An application is presented to evaluate the accuracy and the efficiency of the fatigue numerical methodology: a plate structure tensile operation is firstly simulated followed by the numerical simulation of fatigue test accounting for all the residual state due to the previous metal deformation.