A constitutive model for C45 steel alloys is proposed in this work by integrating the effect of damage and a specific phenomenon, so-called dynamic strain aging. For damage modeling, an energy-based isotropic damage model is implemented within a frame of continuum damage mechanics. The total stress is decomposed into athermal and thermal elements. The former includes the additional term for dynamic strain aging. This term is conceptually inspired by the probabilistic nature of dynamic strain aging, and its derivation is micromechanics-based. Both athermal and thermal components are defined as a function of temperature, equivalent plastic strain, and equivalent plastic strain rate because the occurrence and characteristics of dynamic strain aging are dependent on these factors. A finite element solution for the developed model is addressed additionally to further investigate the characteristics of plastic-damage behaviors and dynamic strain aging. The numerical results are compared to the experiments and theoretical predictions for its validation. The modified model developed in this work has largely reduced the number of fitting parameters compared to the previous model originally developed by the authors in 2019. Nevertheless, predictions from the proposed model still capture the experimental data accurately.

中文翻译：

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损伤和动态应变时效对 C45 钢合金塑性响应影响的理论和数值模拟

这项工作通过整合损伤效应和一种特定现象（即所谓的动态应变时效），提出了 C45 钢合金的本构模型。对于损伤建模，在连续损伤力学框架内实现基于能量的各向同性损伤模型。总应力分解为非热应力和热应力。前者包括动态应变老化的附加术语。该术语在概念上受到动态应变老化的概率性质的启发，其推导基于微观力学。非热分量和热分量都被定义为温度、等效塑性应变和等效塑性应变率的函数，因为动态应变时效的发生和特征取决于这些因素。另外还解决了所开发模型的有限元解决方案，以进一步研究塑性损伤行为和动态应变老化的特征。将数值结果与实验和理论预测进行比较以验证其有效性。与作者最初于 2019 年开发的先前模型相比，这项工作中开发的修改模型大大减少了拟合参数的数量。尽管如此，所提出的模型的预测仍然准确地捕获了实验数据。