Parameter identification of the Norton-Bailey creep model using isochronous curves

Structural integrity assessment of metal components in advanced reactor systems operating at elevated temperatures requires calculations that account for the sequence and duration of loading throughout their service life. Numerical simulation of such processes is performed using nonlinear inelastic material models, whose parameters are determined based on experimental data. The development and verification of an automated numerical algorithm for identifying the parameters of the Norton-Bailey creep law are considered. The algorithm utilizes initial data in the form of a set of material isochronous curves at a specific temperature. It implements an optimization procedure aimed at minimizing the discrepancy between the normative and the computed isochronous curves. The generation of the computed isochronous curves is performed using the Abaqus software package. It is demonstrated that the developed algorithm enables the highly accurate identification of the constants for the Norton-Bailey law.