Temperature dependent representation for Chaboche kinematic hardening model

Abstract

The assessment of high temperature components under cyclic deformation conditions increasingly relies on determinations of the stress-strain state at the critical location using nonlinear finite element analysis. An important consideration in such finite element simulations is the used constitutive model. The Chaboche model has been widely accepted as an advanced model for such applications. This study evaluates the variation of Chaboche model parameters with temperature for low cycle fatigue conditions and introduces an approach to systematically calibrate the model for a range of temperatures, rather than for single temperatures. Furthermore, mathematical representations have been proposed to consider the effect of superimposed creep deformation on the Chaboche model parameters. Successful application of the proposed approach/formulation for representing the behaviour of a 10%Cr steel under low cycle fatigue and cyclic/hold deformation conditions for the temperature range of 20-625uC is presented.

Modelling heat-to-heat variability in high temperature cyclic deformation behaviour

“…The parameters of x 01220 for heat I of the 10%Cr steel were determined in Ref. 17 The use of equations (4)-(7) enabled estimation of the Chaboche model parameters for heats II and III based on the available model parameters for heat I and a knowledge of the R p0?2,RT values for the three heats. Using the estimated Chaboche model parameters for heats II and III, Figure 3 compares the estimated Chaboche model representations for the mid-life stress-strain responses of heats II and III with their respective experimental data at different temperatures under LCF and C/H loading conditions.…”

“…A recent study 17 described a procedure for systematically determining the parameters of a kinematic hardening Chaboche model as a function of temperature for both low cycle fatigue (LCF) and cyclic/hold (C/H) conditions. Such procedures determine the model parameters for a single heat of the alloy.…”

“…As an engineering solution, analysis of real structures/components then may be based on the mean or minimum alloy property representations. While description of the cyclic stress-strain properties for the single heat of an alloy is relatively straightforward, even using complex constitutive model formulations, 17 the same is not true for models representing mean or minimum alloy properties.…”

“…-(17) provides an equation set which defines the Chaboche model parameters as a function of temperature and the R p0?2,RT value for a specific heat…”

Simulation of low cycle fatigue stress‐strain response in 316LN stainless steel using non‐linear isotropic kinematic hardening model—A comparison of different approaches

“…For the simulation of cyclic plasticity with “Chaboche non‐linear isotropic kinematic hardening model (NLIKH)”, it has been reported that the kinematic‐hardening (KH) parameters have been obtained either from the first cycle loop or stabilized cycle loop or from the cyclic stress‐strain curve (CSSC) . In addition to this, simulations can also be conducted directly with the experimental hysteresis loop data in combination with the CSSC.…”