Simulation of deformation behavior of porous Titanium using Modified Gurson yield function

Abstract

In this research the stress-strain curve of porous Titanium, as a common material for biomedical application, was predicted using the mechanical properties of fully solid Titanium experimental data. Modified Gurson model (Gurson-Tvergaard-Needleman (GTN) model) was used to predict the plastic response of porous Titanium in compaction. Different values of GTN parameters were used for different initial porosity. It was recognized that volume constancy assumption during plastic deformation of porous media cannot be satisfied due to both of changes in porosity and hydrostatic stress contribution on yielding. It was found that consideration of porosity variation is necessary during deformation for accurate modeling. Also, porous samples represented the same lateral expansion under less axial displacement relative to fully solid sample regarding the GTN model. The stress distribution of porous samples was different from solid sample considering the GTN model and this was predicted different shear banding. Evolution of porosity during deformation leads to linear like stress response in the plastic deformation regime.