Uniaxial/Multiaxial Creep-Ratchetting of Several Types of Steels and Its Constitutive Modelling

Abstract

In the last two decades, ratchetting (or cyclic creep, i.e. cyclic stress-induced strain accumulation) has been intensively studied, and several interesting phenomena have been reported, such as the effects of maximum stress and mean stress in uniaxial ratchetting [1–6]; the effect of the primary stress and its variation in multiaxial ratchetting [6–12]; biaxial strain accumulation [13–17]; time-dependent behavior and creep effect [2, 7, 10, 15–17]; and the effects of temperature and its variation on the material behavior [10, 15–18]. If we look at carefully these experimental data, we can find that the ratchetting behavior strongly depends on types of materials. About this point, Hassan & Kyriakides [19] mentioned that cyclic hardening/softening nature has a significant effect on uniaxial/multiaxial ratchetting, and they also presented constitutive models to describe the different ratchetting behavior appearing for several types of steels. However, they restricted the discussion within the framework of rate-independent plasticity, even though the viscoplasticity of materials (rate-dependent ratchetting or creep effect) sometimes plays an important role in ratchetting.KeywordsStrain AccumulationCyclic HardeningBack StressStress CycleCyclic PlasticityThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.