Yield-point phenomenon in constitutive models of cyclic plasticity

This paper describes the yield-point phenomenon in rate-independent constitutive models of cyclic plasticity. This phenomenon is typical of annealed low-alloy steels and related alloys as well as of some aluminium and titanium alloys and occurs at first transition from the elastic into the elasto-plastic region. The effects of cyclic plasticity are described with constitutive equations of kinematic and cyclic hardening or softening. The advantage of the presented model is that it requires a small number of material parameters which describe the yield-point phenomenon and can be defined using simple uniaxial monotonous experiments. In order to define material parameters and establish the stress–strain response of the constitutive model in comparison with the actual state, uniaxial monotonous and uniaxial cyclic tension–compression experiments were carried out. The model is included in the finite element code the use of which helps to simulate the contribution of the model to the development of the stress–strain state in a real structure.