Comparison of elastic properties of open‐cell metallic biomaterials with different unit cell types

Abstract

Additive manufacturing techniques have made it possible to create open-cell porous structures with arbitrary micro-geometrical characteristics. Since a wide range of micro-geometrical features is available for making an implant, having a comprehensive knowledge of the mechanical response of cellular structures is very useful. In this study, finite element simulations have been carried out to investigate the effect of structure unit cell type (cube, rhombic dodecahedron, Kelvin, Weaire-Phelan, and diamond), cross-section type (circular, square, and triangular), strut length, and relative density on the Young's modulus, shear modulus, yield stress, shear yield stress, and Poisson's ratio of open-cell tessellated cellular structures. It was desired to see whether or not and to what extent each of the aforementioned parameters affect the mechanical properties of a porous structure. It was seen that the strut cross-section type does not have a considerable effect on the structure Young's modulus while its effect on the structure yield stress is significant. The strut length was not effective on the mechanical properties if the relative density was kept constant. It was also observed that the structure unit cell type and relative density have a considerable effect on the elastic properties. The highest and the lowest stiffness and strength belonged to the cube and diamond unit cell types, respectively. The rhombic dodecahedron structure with circular cross-section had a high yielding strength (second among all the cases) while its Young's modulus was relatively low. Therefore, it is the best choice for applications with low stiffness requirements, such as biomedical implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 386-398, 2018.

Non-Auxetic Mechanical Metamaterials

“…The yield stress of the rhombic dodecahedron was somewhat lower than the truncated cuboctahedron, while their values started to overlap at higher values of relative density [18,19]. The cube, on the other hand, possessesed the highest yield stress and first maximal stress in all studies (Figure 6 and Figure 7) [12,18,19,42,45,51]. In terms of the Young’s modulus, the cube was surpassed by the truncated cube, which has been shown to be the stiffest unit cell studied [18].…”

Three dimensional modeling method of MIMICS adjacent mask spherical open cell aluminum foam-polyurethane composites based on DICOM data

“…Because it was a simple model, it could only be used for the foamed structure material with a relative lower density. After correcting and optimizing this simple model, the cubic plate model was developed, and then the docecahedral [6] and tetrakaidecahedral models [7] were generated through further model optimization. However, these simple models could not approximate the real inner pore structure of metal foam, leading to significant difference between the simulation results and the experimental results.…”

Mechanobiological Approach to Design and Optimize Bone Tissue Scaffolds 3D Printed with Fused Deposition Modeling: A Feasibility Study

“…To this purpose, both regular and irregular scaffold geometries were proposed and investigated. The regular scaffolds include unit cell configurations all with the same shape and dimensions that are regularly replicated in the scaffold volume [1,2]. Analytical solutions were recently developed that put in relationship the equivalent material properties of the entire scaffold with the dimensions and the material properties of the single unit cell [3][4][5][6].…”