Johnson−Cook dynamic constitutive relationship for TC16 titanium alloy
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: The true stress—strain curves of TC16 alloy with a wide range of strain rates were investigated under uniaxial quasi-static tension and uniaxial dynamic compression with the Instron 8032 test machine and the split Hopkinson bar respectively. The results indicate that the true stress increases with increasing strain rate, while decreases with increasing temperature. Under the 105 s−1 high strain rate and temperature higher than 673 K, the true stress would even be less than that under quasi-static condition. A new method incorporating TC16’s stress—strain curve developing item was proposed to determine the coefficients in J−C model easily and to avoid the estimation of the adiabatic temperature rising. The Johnson−Cook dynamic constitutive relationship for TC16 was obtained for the first time. Good agreement was obtained between the model prediction and the experimental stress—strain curves for TC16 under both quasi-static and dynamic loadings.
Key words: TC16 titanium alloy; dynamic constitutive relationship; SHPB; strain rate; temperature