The Meso-inhomogeneous Deformation of Pure Copper under Tension–Compression Cyclic Strain Loading

Abstract

The investigation based on experiments and crystal plasticity simulation is carried out to undertake research on meso-deformation inhomogeneity of metals under cyclic loading at grain level. Symmetrical tension–compression cycle tests are performed on pure copper specimens to observe the inhomogeneous distribution of slip deformation and its evolution with cycle number. Cyclic hardening process and stable hysteretic behavior of pure copper under cyclic loading are simulated by applying a crystal plasticity constitutive model including nonlinear kinematic hardening associated with the polycrystalline representative volume element (RVE) constructed by Voronoi tessellation. Inhomogeneous deformation processes of materials under six different strain amplitudes are simulated by 1600 cycles, respectively. We discuss the variation law of the inhomogeneous meso-deformation distribution of material with the increase in cycle number, and research the rationality of characterizing the inhomogeneous deformation distribution and variation with the statistical standard deviation of the micro-longitudinal strain or the statistical average of the first principal strain based on the statistical analysis of the inhomogeneous deformation of the polycrystalline RVE model during the cycling process. It is found that these two parameters are related to and approximately inversely proportional to the length of measuring gauge.