Constitutive Modeling for Uniaxial Time-Dependent Ratcheting of SS304 Stainless Steel

Abstract

Based on the experimental results of uniaxial time-dependent ratcheting behavior of SS304 stainless steel at room temperature and 973K, three kinds of time-dependent constitutive models were employed to describe such time-dependent ratcheting by using the Ohno-Abdel-Karim kinematic hardening rule, i.e., a unified viscoplastic model, a creep-plasticity superposition model and a creep-viscoplasticity superposition model. The capabilities of such models to describe the time-dependent ratcheting were discussed by comparing with the corresponding experimental results. It is shown that the unified viscoplastic model cannot provide reasonable simulation to the time-dependent ratcheting, especially to those with certain peak/valley stress hold and at 973K; the proposed creep-plasticity superposition model is reasonable when the creep is a dominant factor of the deformation, however, it cannot provide a reasonable description when the creep is weak; the creep-viscoplastic superposition model is reasonable not only at room temperature but also at high temperature.

An evaluation for several kinematic hardening rules on prediction of multiaxial stress-controlled ratchetting

“…Especially, a significant achievement in simulating uniaxial as well as multiaxial ratchetting has been observed during the last 10 years since several robust kinematic hardening rules (which are responsible for simulating ratchetting) have been developed (see the review paper of Chaboche (2008) and Kang (2008) and the recent works of Kang and Kan (2007), , , , Kan and Kang (2009), and Kang et al (2009a,b)). …”

Effect of frequency of free level fluctuations and hold time on the thermal ratcheting behavior

“…In this regard, visco-plasticity-creep superposition model (SVC) that simulates uniaxial time dependent deformation is considered by the superposition of multiaxial visco-plasticity and multiaxial creep law [23] as shown below:…”

“…Several researchers [34e36] have investigated the interaction between plasticity and creep. It was demonstrated [23] that the UVP model satisfactorily simulates the uniaxial ratcheting behavior with negative stress ratio and at moderate stressing rates. However, it yielded poor results under lower stressing rate at which the creep strain becomes a main part of rate-dependent ratcheting strain.…”

“…Thus, significance of rate dependence is observed in these literature using different time dependent constitutive models. It was reported that plasticity-creep superposition model (SPC) is suitable when hold time/creep effect is to be accounted while unified visco-plastic constitutive model (UVP) is preferred to account visco-plastic behavior (without hold time/creep) [23].…”

Stress-Strain Behaviors Simulation of High Chromium Steel at Elevated Temperatures

“…For example, numerical simulations of the stress fields of rollers are very important, which are helpful to predict hot crack, cold crack, and deformation. The bases of thermal stress analyses during casting process are the numerical simulations of temperature fields, which are basically mature ( Ref 1,[7][8][9][10][11][12][13][14][15][16]. The stress simulation of solidified ingot shells was first performed by using analytical method in 1960s.…”