Mechanical Characterization and Numerical Simulation of the Ti6Al4V Porous Scaffolds Based on Weaire-Phelan Structure / 医用生物力学

ABSTRACT

Objective To study mechanical properties of porous scaffolds with lattice Weaire-Phelan (LWP) structure and precisely simulate the whole process of compression test using finite element method. Methods The Ti6Al4V (TC4) porous scaffolds with different porosities were manufactured by selective laser melting (SLM) technology, and their mechanical properties were measured by uniaxial compressive tests, and compared with those of human bones and porous scaffolds with other cellular structures. Four types of material models were verified for their effects on the simulation of porous scaffold compression. Results LWP samples presented the elastic modulus close to that of human cancellous bone and significantly higher yield strength than that of cortical bone in most parts of human body. Compared with other scaffold structures, LWP samples exhibited the lowest elastic modulus and highest yield strength. The simulated results derived from the proposed material model in this study, namely, Johnson-Cook constitutive model and failure model based on dynamic geometric strain (JCDG), were proved very consistent with the experimental data. Conclusions LWP scaffolds as the bone repair biomaterials exhibite more excellent mechanical properties than the scaffolds with other structures. JCDG is more beneficial for establishing the reasonable simulation model of porous scaffolds compression, compared with other reported material models.