Morphological Characteristics and Stress Analysis of 3D Printed Trabeculae

In this paper, the morphological characteristics and mechanical properties of 8 kinds of trabecular cell structures were analyzed by finite element analysis software. The cell structures were enlarged by 25 times and were fabricated using polymer materials by a 3D printer. The reliability of the simulation was proved by comparing the compression law of load and deformation experiments with the simulation results. According to the need of pore and strength of bone trabecula, the structure of bone trabecula with high porosity and strength is screened. Then the cuboid and cylindrical models composed of multi-cell elements are constructed. The load-carrying capacity and stress distribution of the two shapes specimens are analyzed numerically. Titanium alloy bone trabecular specimens with rectangular cross section were fabricated by electron beam 3D printing, and compression tests were carried out. The simulation results show that the porosity of cell structure is inversely proportional to the carrying capacity. The circular section specimens have a lower load-carrying capacity than rectangular section specimens because of the broken ends of struts. The influence of strut size on the load-bearing capacity of specimens is obvious. Increasing strut size appropriately can effectively improve the load-bearing capacity of bone trabecular structure. Compression experiments show that there are two yielding stages in the compression process of 3D printed titanium alloy bone trabecular structure, and the real failure of the specimen is in the second yielding stage.