Self-consistent modeling of the mechanical behavior of an austenitic stainless steel under low cycle fatigue loading
ICMM5 – 5th International Conference on Material Modelling, Rome, Italy, 13-16 June 2017
Experimental results of low cycle fatigue (LCF) tests, with different total strain amplitudes from ±0.5% to ±1.25%, show that the studied austenitic stainless steel 316L undergoes an initial hardening followed by a large softening range, and then reaches stress stabilization until fracture. Furthermore, stress analysis highlights obvious strain range effect for this material during cyclic loading. In this work, an elastic-inelastic self-consistent model for polycrystals is used to simulate the mechanical behavior of the material under uniaxial low cycle fatigue loadings. A modified kinematic hardening variable χ^s and a set of isotropic hardening variables k^s, associated with state variables of crystal slip systems, are proposed to describe the hardening/softening behavior of the material. Along with the parameters concerning grain/matrix interaction law and homogenization method, material parameters of kinematic and isotropic hardenings are identified using optimization methods. With the identified parameters, it is shown that the modified model is able to well describe the cyclic hardening/softening behavior as well as the strain range effect under uniaxial loading.