Based on Chaboche constitutive model, a viscoplastic constitutive model of nickel-based alloy under multiaxial loading is proposed by introducing Lemaitre damage model and non-proportional hardening factor. Lemaitre damage model can characterize the effect of microscopic defects on the fatigue behavior and non-proportional hardening factor is used to describe non-proportional hardening phenomenon. Subsequently, the stress–strain hysteresis loops at room and high temperatures under different loading conditions are simulated by the proposed constitutive model. Comparison between experiments and simulations confirms that the proposed model can reasonably predict the fatigue behavior of nickel-based alloy under different multiaxial loadings. At last, the fatigue life predictions under different multiaxial loadings are investigated, and comparison between experiments and simulations verifies the accuracy of the proposed model.

在Chaboche本构模型的基础上，通过引入Lemaitre损伤模型和非比例硬化因子，提出了镍基合金在多轴载荷下的粘塑性本构模型。Lemaitre损伤模型可以表征微观缺陷对疲劳行为的影响，并且非比例硬化因子用于描述非比例硬化现象。随后，通过所提出的本构模型对室温和高温下不同载荷条件下的应力-应变磁滞回线进行了仿真。实验和仿真结果的比较证实，所提出的模型可以合理地预测镍基合金在不同多轴载荷下的疲劳行为。最后，研究了不同多轴载荷下的疲劳寿命预测，