Prediction of Cyclic Behaviors of Mild Steel at Large Plastic Strain Using Coupon Test Results

Abstract

In practice, engineers can usually only obtain material properties from monotonic tensile coupon tests. The aim of this paper is to predict cyclic plasticity of mild steel from coupon test results available. First, the theory of metal plasticity is generally reviewed, and selected models are introduced, i.e., Prager’s hardening rule, the Chaboche models, and the Yoshida-Uemori model. Calibration methods of the material parameters of each model are proposed and limitations of the models are addressed. Then, a modified Yoshida-Uemori model is proposed. Monotonic tensile coupon tests and a series of tests of hourglass-type specimens were carried out under different loading histories to fracture. Numerical simulations using the selected plasticity models and the modified Yoshida-Uemori model were carried out to simulate the cyclic behaviors of hourglass-type specimens using the material parameters calibrated by the monotonic coupon test results. The comparison results show that the modified Yoshida-Uemori model gives the best prediction of the cyclic behaviors of mild steel in large plastic strain ranges.