EXPERIMENTAL INVESTIGATIONS INTO THE INFLUENCE OF CYCLIC PHENOMENA OF METALS ON STRUCTURAL RATCHETTING BEHAVIOR

The results of experiments on 2-bar structures of 99. 9% copper are compared with the prediction of classical plasticity models for loading histories which simulate the effects of thermal cycling in the presence of constant primary loading. Two material phenomena, cyclic hardening and material ratchetting, are shown to have important effects upon cyclic strain growth. Neither of these effects are contained in classical plasticity models. The steady state growth of strain due to material ratchetting is modeled in a simple way. An approximate solution method, based on the 'rapid cycle' method for creep analysis, is shown to give a good prediction of the experimental data.