Identification of strain hardening behaviors in titanium alloys using tension tests and inverse finite element method

This study proposes an inverse methodology for determining the strain hardening behaviors at large deformation of titanium alloys using uniaxial tensile and notched tests with finite element analysis. Various hardening laws and data fitting range are considered to characterize the stress-strain relationships of commercially pure titanium (CP-Ti) and Ti6Al4V alloys which can increase the flexibility of identifying the proper models. A new hybrid HHSL hardening model is presented for CP-Ti and its parameters are obtained by iteratively minimizing the difference between the finite element simulation and experimental data. The hardening behavior of Ti6Al4V alloy is predicted by the weighted HSV model. The results show that mechanical response and loading curves from the identified numerical models are consistent with the experimental results of titanium alloys, demonstrating the validity and effectiveness of the proposed inverse approach in practical use.