Comparative Analysis of 3 Constitutive Models for 93 Tungsten Alloy

In this research, we carried out a systematic study of the mechanical behaviors of the 93 tungsten alloy (93%W-4.9%Ni-2.1%Fe) with a temperature range of 296-1273 K and a strain rate range of 0.000 5-6000 s^-1. The results demonstrate that the flow stress is highly dependent on the temperature and the strain rate: the flow stress increases with the decrease of temperature and the increase of strain rate, and the shear failure does not occur when the true plastic strain is up to 0.6. Then we introduced and established 3 constitutive models, including two phenomenological constitutive models, JC model and KHL model and one physically-based constitutive model, to fit the stress-strain relationship through a procedure of regression analysis and constrained optimization. Finally, we evaluated the fitted results of the 3 constitutive models through a fitting error analysis and a specific strain-rate jump experiment.