In the framework of continuum damage mechanics, a new damage-coupled cyclic plastic model is proposed to describe the nonlinear evolution of whole-life ratchetting and its dependence on the stress level. The characteristic that the damage evolution rate of U75V heat-treated steel decays in the initial load cycles is considered by introducing a modified term into classic damage evolution equation. A hybrid fatigue failure criterion considering both the fatigue and ratchetting strain-induced failures is established based on the fatigue failure rule concluded from experiments. Comparisons between simulated and experimental stress–strain hysteresis loops, ratchetting strains, damage evolutions, and fatigue lives are performed to validate the proposed model.

中文翻译：

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一种新的损伤耦合循环塑性模型，用于热处理 U75V 钢的全寿命棘轮齿

在连续介质损伤力学的框架内，提出了一种新的损伤耦合循环塑性模型来描述全寿命棘轮的非线性演化及其对应力水平的依赖性。通过在经典损伤演化方程中引入修正项，考虑了U75V热处理钢在初始载荷循环中损伤演化速率衰减的特性。根据实验得出的疲劳失效规律，建立了一种同时考虑疲劳和棘轮应变引起的失效的混合疲劳失效准则。对模拟和实验应力-应变滞后回线、棘轮应变、损伤演变和疲劳寿命进行比较，以验证所提出的模型。