Highlights

• •The cyclic softening feature of carbide-free bainitic rail steel is revealed.

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• •A modified yield function is introduced to consider the strength differential effect.

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• •A new function is introduced to consider the transient Bauschinger effect.

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• •A new cyclic softening function is introduced to describe the strain amplitude-dependent cyclic softening.

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• •The hysteresis loop evolution is simulated reasonably.

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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.

Link

https://doi.org/10.1016/j.ijfatigue.2022.106922