Viscoplastic constitutive model of a nickel-based superalloy under multiaxial loading conditions

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.

Automated summary

This study proposes a viscoplastic constitutive model for nickel-based alloy under multiaxial loading, incorporating Lemaitre damage model and non-proportional hardening factor. Simulation results of stress-strain hysteresis loops under different conditions show that the model accurately predicts fatigue behavior and life of the alloy. Experiments and simulations confirm the validity and accuracy of the proposed model.