Model of Low-Cycle Deformation of Stainless Steel Under Soft Loading

A variant of the plasticity model is proposed that allows describing the kinetics of plastic deformation of materials under different modes of low-cycle loads. In the model, the radius of the flow surface is represented as a function depending on temperature and accumulated plastic deformation, and the coordinates of the center are described by two Armstrong-Frederick-Kadashevich-type evolutionary equations, the first of which additionally introduces corrective material functions. Changes in plastic deformations in the model are determined based on the associated flow law. Receiving material functions of the model and testing it was carried out on the basis of the results of experimental study of the deformation of a cylindrical sample under soft cyclic loading with maximum control and minimum effort in the cycle. The experiments were carried out on the Amsler HA 100 servo-hydraulic fatigue testing machine. Comparative analysis of the results of numerical simulation and experiment shows that the proposed model allows us to describe the main effects of plastic deformation of the material under consideration under soft asymmetric loads (displacement of the plastic hysteresis loop and reduction of its width) quite well.