Dynamic shear characteristics of titanium alloy Ti-6Al-4V at large strain rates by the split Hopkinson pressure bar test

The focus of this paper is the dynamic shear characteristics of titanium alloy Ti-6Al-4V at large strain rates. Dynamic load testing of titanium alloy Ti-6Al-4V are performed by the split Hopkinson pressure bar (SHPB) at different strain rates, which involve the SHPB compression test and the SHPB shear test. The material behaviour during the tests are measured and recorded. The strain rates for the compression and shear tests range from 5.0 x 10(2) s(-1) to 9.0 x 10(3) s(-1) and 1.0 x 10(4) s(-1) to 3.0 x 10(5)s(-1), respectively. The effect of competing mechanisms-strain rate hardening and thermal softening-on the adiabatic shear band is analysed. A size effect on shear band width is also found. According to the results, a modified Johnson-Cook U-C) constitutive model is applied to tests at an ultrahigh strain rate. Furthermore, a finite element method (FEM) simulation is conducted to validate different aspects of the methodology. The SHPB shear test is confirmed as a process of pure shear. A comparison of the shear stress-strain curves from the mechanical tests and simulation show good agreement based on the modified J-C constitutive model. 2017 Elsevier Ltd. All rights reserved.