CAE analysis on the mechanical properties of a 3D-printed lattice structure from Ti-6Al-4V for biomedical applications

Abstract

This study investigates the structural compression properties of the additive manufactured (AM) Ti-6Al-4V lattice structure using LS-Dyna simulation analysis software and calculates its mechanical properties under different porosities and different pattern designs. Ti-6Al-4V alloys formed by using additive manufacturing produced elliptic holes with long and short axes due to the difference in the direction of construction. These holes could be eliminated and the materials could be compacted by hot isostatic pressing (HIP) treatment. Compactness of the frame element achieved 99.9% and drastically reduced the anisotropic behavior caused by the fabrication process. For the experimental testing, the samples with different porosities and the A-type and AZ-type designs were employed in compression experiment. In the meantime, the Young's modulus, the yield strength, plateau stress and other mechanical behavior were investigated by CAE simulation. The plateau stress, which is an important property for some biomedical applications, was calculated with satisfactory accuracy compared with experimental measurements. The simulated results of the designed lattice structures with different porosity contents were able to adopt the Gibson-Ashby model to determine their failure mechanisms. Finally, the CAE simulation for the design of an auxetic material was demonstrated.