基于反双曲正弦函数的循环本构模型

为改善本构模型对循环变形应力-应变滞回环的预测能力,基于反双曲正弦函数提出了一个新的随动硬化律.在该硬化律中,背应力分为长程、中程和短程3部分,并且每部分都符合"A-F"硬化律的演化形式(即包含线性项和动态恢复项).在长程和中程背应力中,动态恢复系数逐渐演化以描述大变形瞬态包辛格效应,并且系数中引入了棘轮系数以描述材料...

An Arcsinh-function Based on Cyclic Constitutive Model

A novel kinematic hardening rule is proposed to improve the predictive capability for cyclic stress-strain hysteresis loops. In the proposed rule, the back stress is decomposed into long, middle and short-range components with each addressing an " A-F"evolution rule consisting of a linear hardening and a dynamic recovery term. For the long and middle-range components, the dynamic recovery coefficients are postulated to be evaluated with deformation to describe the transient Bauschinger effect and each contains a ratchetting coefficient accounting for ratchetting evolution. For the short-range component, the linear hardening and dynamic recovery terms are further divided into two parts respectively, with one part in each activating only when the reverse loading occurs to describe the lower plastic modulus at initial yielding stage during cyclic loading. Under the monotonic loading condition, the proposed rule is integrable and the integration form yields an Arcsinh-function. Besides, the material parameters for the proposed rule related to monotonic loading response, ratchetting behavior and stress-strain hysteresis loops can be determined separately. Finally, incorporating the proposed rule, a cyclic constitutive model is developed in the hypo-elastic finite deformation framework and the predictive capacity for ratchetting behavior and stress-strain hysteresis loops is validated.