Abstract:The true stress—true strain curves of Ti-3%Al-5%Mo-4.5%V alloy with a wide range of strain rates were investigated under uniaxial quasi-static tension and uniaxial dynamic compression respectively with Instron 8032 test machine and the split Hopkinson bar. A new method incorporating the stress—strain curve of Ti-3%Al-5%Mo-4.5%V alloy was proposed for determining the parameters based on Johnson-Cook model easily and avoiding the estimation of adiabatic temperature rising. The Johnson-Cook dynamic constitutive relationship for Ti-3%Al-5%Mo-4.5%V alloy was obtained. The results show that the true stress increases with increasing strain rate, while decreases with increasing temperature. Under the condition of high strain rate of 105/s and temperature above 673 K, the true stress is even less than that under quasi-static condition. Good agreement is obtained between the model prediction and the experimental stress—strain curves for Ti-3%Al-5%Mo-4.5%V alloy under both quasi-static and dynamic loadings.

Key words: TC16; dynamic constitutive relationship; SHPB; strain rate; temperature