Effects of different porosity volume fractions on the mechanical properties and global orthotropic behavior of gelatin closed-cell bio-foams

In this study, two micromechanical models for gelatin closed-cell bio-foams with different porosity volume fractions are presented to investigate porous structures' global orthotropic behavior. A wide range of porosity from zero% to ۶۳% of volume fractions, together with ۳-D distributions of spherical shaped pores, are considered. Both Mori-Tanaka's (M-T) analytical model and finite elements (FE) based models are implemented for analyzes. At first, a code for random algorithms in PYTHON is developed to reconstruct ۳-D representative volume elements (RVEs) containing randomly distributed non-overlapping pore cells for implementing finite element simulations. Then, such models revealed a discrepancy interval between M-T procedure and FE based models from ۰% in the relative density of ۱ in most of the orthotropic elastic components, and exceptionally in relative density of ۰.۳۷ at (E۶۶)*/ (E۶۶)S fraction up to ۸% in the relative density of ۰.۳۷ at (E۱۱)*/ (E۱۱)S fraction due to the varying porosity volume fractions within analyzed samples when such materials showed orthotropic global behavior. Homogenized Young's moduli, driven from FE models of such materials, decreased due to porosity concerning the bulk material having a wide-ranging interval so that zero% Young's modulus reduction in relative density of ۱ up to ۷۹.۷۱۸% in relative density of ۰.۳۷ was seen.

Keywords:

Biomimetics , Closed-Cell Foams , Heterogeneous Materials , Micromechanics , Porous Materials , RVE