Modeling the mechanical properties of lattice structures made by selective laser melting

Abstract

Nowadays, materials with graded density are of great interest. These materials are manufactured with the use of additive technologies and consist of multiple lattice structures with variable parameters and topology. By varying the parameters of the lattice structures, one can adjust the mechanical properties of the material as required. The paper proposes an original methodology for predictive modeling of mechanical properties of graded materials with the help of numerical simulation tools for the further design of the human femur endoprosthesis. The developed methodology is based on varying the topology of lattice structures with the consideration of the technological capabilities of additive manufacturing. The materials under the study allow creating endoprostheses with mechanical properties close to those of the human femur. The periodic structure of these materials ensures ingrowing of bone tissue into the endoprosthesis. Endoprostheses made of materials with graded density are superior to the traditionally manufactured prostheses. Endoprostheses manufactured by means of traditional methods are of higher stiffness than bones, thus, during exploitation they can cause bone damage or fracture. The authors applied a combination of biological and mechanical selection criteria for various zones of endoprosthesis and defined variants of topologies of the lattice structures corresponding to the mechanical properties and geometry of the human femur. With the use of the selected quasi-optimal lattice structures topologies, a femur-like endoprosthesis prototype can be designed for its further fabrication with the use of additive manufacturing methods.