Effect of yield criterion and variable elastic modulus on springback prediction of Ti-6Al-4V sheet V-shaped bending

In recent years, Ti-6Al-4V titanium alloy has been widely used in many fields because of its excellent material properties. However, the complex properties of Ti-6Al-4V titanium alloy make the common material constitutive model no longer applicable. It is difficult to accurately analyze the deformation process of Ti-6Al-4V titanium alloy in theoretical analysis or numerical simulation. In this paper, we take Ti-6Al-4V titanium alloy as the research object, and the change of elastic modulus of Ti-6Al-4V titanium alloy was studied. A mathematical model of titanium alloy variable elastic modulus was established. Based on the YLD2000-2D yield criterion and the mathematical model of variable elastic modulus, the constitutive model of Ti-6Al-4V titanium alloy was established. We have carried out the numerical simulation and field experiment of V-bending springback of Ti-6Al-4V titanium alloy sheet. The springback prediction accuracy of three different constitutive models was compared and analyzed. The influence of yield criterion and elastic modulus on springback prediction of titanium alloy V-bending was studied. The results show that the constitutive model established in this paper significantly improved the springback prediction accuracy of the numerical simulation of titanium alloy sheet bending. This work has made a great contribution to the field of titanium alloy bending forming.