Design, testing, and mechanical behavior of additively manufactured casing with optimized lattice structure

Additively manufactured internal lattice structures offer a unique approach to lightweight components and adding multi-functionality. Design methods for parts based on lattices are emerging and include a family of topology optimization schemes for tailoring local cell density to service loadings. In order to gain confidence, these methods must be validated in a controlled manner. In this paper, we report optimization, analysis, manufacturing, and mechanical test validation of a casing-like test article. The test article was optimized using a stress-based homogenized topology optimization approach and achieved a 53% weight reduction versus a solid, fully-dense casing with the same form factor. The optimized geometry was studied with high-fidelity finite element analysis and then additively manufactured. Mechanical testing was performed and demonstrated good correlation between the homogenized finite element model used for optimization, the high-fidelity finite element model, and experimental results. The findings validate the optimization approach for the particular use and load case and start to build confidence in the approach as an accepted method.