Strain amplitude-dependent cyclic softening behavior of carbide-free bainitic rail steel: Experiments and modeling

Abstract

Experimental investigations of Carbide-free bainite (CFB) rail steel under different strain amplitudes are conducted to indicate the cyclic deformation feature and hysteresis loop evolution. A modified yield function with an exponential evolution coefficient is proposed to consider the strength differential effect, and a strain range-dependent coefficient is introduced to consider the transient Bauschinger effect. Moreover, a Logistic dose–response function and a cyclic softening function are introduced into the isotropic and kinematic hardening rules. Finally, the comparison between the simulated and experimental results demonstrates that the proposed model can reasonably describe the strain amplitude-dependent cyclic softening of CFB rail steel.