A novel method combining finite element analysis and computed tomography reconstruction to master mechanical properties of lattice structures processed by laser powder bed fusion

Abstract

The inherent manufacturing defects in laser powder bed fusion (LPBF)-processed samples leads to deviations from results of finite element analysis (FEA) using the designed model. To systematically evaluate process-induced defects and elucidate their effect, a novel methodology, combining statistical analysis, precision computed tomography (CT) characterisation techniques, mechanical properties assessments and FEA, has been developed. Compared to designed models, CT reconstructed models consider defects, which may affect mechanical properties evaluation, especially along the building direction. FEA based on the CT reconstructed model can more accurately display the stress distribution and the anisotropy of samples. Results indicate that mechanical properties correlate with geometric structure and building direction. Anisotropy becomes more pronounced at a strut diameter of 1.0 mm, the universal anisotropic index AU can reach to 6.31. Overall, this method improves predictive ability by elucidating structure–property relationships in LPBF-processed lattice structures, offering insights into the efficient design for LPBF-processed lattice structures with desirable mechanical properties.

Keywords

• Laser powder bed fusion
• lattice structures
• orthogonal experiment
• CT reconstructed model
• finite element analysis (FEA)
• anisotropy