Modeling of the fatigue behavior of functionally graded materials: Study of the residual stresses induced by surface severe plastic deformation

Abstract

AbstractA new finite elements approach has been used to model the evolution of residual stresses during cyclic loading in functionally graded 316 L stainless steel, obtained by surface severe plastic deformation. The affected layer modeling was divided in two stages: the compressive residual stress state initialization and the update of the mechanical properties characteristic of the gradient microstructure determined from local characterization. The capacity of the model to simulate both the strain‐ and stress‐controlled fatigue behavior was evaluated, and a good consistency between the numerical and experimental results was obtained. Numerical residual stress fields were compared to the experimental measurements, and a very good agreement was observed. A mean error of approximately 65 MPa over all the compared data was measured. Especially, the relaxed and inverted residual stress gradient after the different testing conditions were nicely retrieved, indicating the capabilities of the newly proposed model.