HYBRID STRUCTURAL ISOTROPY RESEARCH BASED ON LATTTICE STRUCTURES

The mechanical properties of lattice porous structures are usually anisotropic. In the engineering applications of porous bone implants, stress shielding effect may occur in some directions due to the anisotropy of elastic modulus. To solve these problems, the mechanical properties and isotropy of typical lattice structures are analyzed by means of homogenization theory and finite element analysis. The results show that the structure porosity has a great influence on isotropy, i.e., the greater the porosity, the greater the Zener factor. The lattices of Gyroid and Edge-centered cube are the best isotropy, while the lattices uniformity of I-WP and Body-centered cubic are poor. In order to achieve the effect of isotropy, the hybrid elements of Primitive and Body-centered cubic can optimize the structural isotropy. The Zener factor of P60BCC65, P65BCC70, P70BCC70 and P75BCC80 structures is close to 1, and the Zener factor of P75BCC80 lattice structure is 1.02 and the porosity is 62.4%, which is within the applicable orthopedic implant porosity range.