Cyclic plasticity of structural elements made of materials which exhibit the yield-point phenomenon

At first transition from the elastic into the elasto-plastic region, many materials which structural elements are made from exhibit the yield-point phenomenon. In the event of uniaxial cyclic experiments, the yield-point phenomenon is visible only in the first cycle. However, the authors of this paper have proven that the yield-point phenomenon affects the stress-strain response during the entire lifetime of structural elements which are subject to cyclic plasticity. Taking account of the yield-point phenomenon in constitutive models of cyclic plasticity significantly improves the forecast of the stress-strain response and the lifetime of structural elements. For constitutive models of cyclic plasticity, a description and benefit of the yield-point phenomenon during the development of the stress-strain state of a cyclically loaded structural element are presented by comparing experiment and numerical simulation results. In the paper, the emphasis is placed on detailed determination of the benefit as well as the functionality and necessity of taking account of the yield-point phenomenon in constitutive models of cyclic plasticity.