Simulation of low cycle fatigue stress-strain response in 316LN stainless steel using non-linear isotropic kinematic hardening modelA comparison of different approaches

Cyclic stress-strain response of 316LN stainless steel subjected to low cycle fatigue at strain amplitude of +/- 0.4% and at 873K is simulated using finite element analysis with non-linear isotropic-kinematic hardening Chaboche model. Four different approaches have been used in simulating cyclic stress response and hysteresis loops: 3 based on Chaboche model-parameters and the fourth on direct experimental data (stabilized loop and cyclic stress-strain curve [CSSC]). Among them, simulations performed with direct experimental data have not yielded expected initial cyclic response. The source of data used for evaluation of kinematic-hardening (KH) parameters determined the extent of closeness between experimental results and Chaboche-model predictions. KH parameters determined from first-cycle loop and modified-CSSC predicted the overall stress-strain response (from initial to stabilized condition) with reasonable fit, compared with other approaches. All 4 approaches though predicted stabilized response, simulations based on KH-parameters from stabilized-cycle accurately described stabilized response with coefficient of determination (r(2)) 0.995.