Modeling the multiaxial fracture behavior of Ti–6Al–4V alloy sheets at a high temperature using improved damage modeling

Abstract

In this study, the mechanical responses of Ti–6Al–4V alloy sheets at a high temperature under multi-axial loading were investigated using a micromechanics-based damage model within a continuum finite element (FE) framework. Tensile tests at three strain rates and a high temperature were conducted to analyze the plastic and ductile damage properties of the Ti–6Al–4V alloy sheets. Additionally, hot Nakajima tests were conducted on specimens with three different shapes to evaluate the improvement in formability at a high temperature. Moreover, the dimples on the fractured surfaces of the experimental samples were qualitatively analyzed. Simultaneously, corresponding FE simulations were conducted to predict the ductile damage behavior of the Ti–6Al–4V alloy sheets at a high temperature using a modified Gurson−Tvergaard−Needleman model. The predicted results and the displacements at the onset of failure were compared with the corresponding experimental data.