1D cyclic yield model independent of load spectrum characteristics and its application to Inconel 718

At room temperature, nickel-based superalloy Inconel 718 softens under fully reversed plastic deformation cycles. Chaboche's unified constitutive equations have been previously used in the literature to predict nickel-based superalloy cyclic softening behavior. To better fit our results, the constitutive equations were modified to account for continuous softening. Moreover, applying the model to results gathered from two different loading spectrum indicates that the isotropic evolution is solely dependent on the accumulated plastic strain and can be applied to a variety of number of cycles and strain amplitudes combinations without adjusting the parameters. This new information is significant and has a considerable impact on material testing and modeling. It implies that a unique set of parameters extracted from any fully reversed strain controlled test can characterize the material flow stress evolution with accumulated plastic strain independently of the strain sequence, for Rɛ=−1. This flexible prediction method could lead to significant experimental costs reductions.