Micro computed tomography based finite element models for elastic and strength properties of 3D printed glass scaffolds

In this study, the mechanical properties of glass scaffolds manufactured by robocasting are investigated through micro computed tomography (mu-CT) based finite element modeling. The scaffolds are obtained by printing fibers along two perpendicular directions on parallel layers with a 90 circle tilting between two adjacent layers. A parametric study is first presented with the purpose to assess the effect of the major design parameters on the elastic and strength properties of the scaffold; the mechanical properties of the 3D printed scaffolds are eventually estimated by using the mu-CT data with the aim of assessing the effect of defects on the final geometry which are intrinsic in the manufacturing process. The macroscopic elastic modulus and strength of the scaffold are determined by simulating a uniaxial compressive test along the direction which is perpendicular to the layers of the printed fibers. An iterative approach has been used in order to determine the scaffold strength. A partial validation of the computational model has been obtained through comparison of the computed results with experimental values presented in [10] on a ceramic scaffold having the same geometry. All the results have been presented as non-dimensional values. The finite element analyses have shown which of the selected design parameters have the major effect on the stiffness and strength, being the porosity and fiber shifting between adjacent layers the most important ones. The analyses carried out on the basis of the mu-CT data have shown elastic modulus and strength which are consistent with that found on ideal geometry at similar macroscopic porosity.