Additive Manufacturing of Honeycomb Lattice Structure-From Theoretical Models to Polymer and Metal Products

• Published in: Materials Vol. 15; no. 5; p. 1838
• Main Authors: Goldmann, Tomáš, Huang, Wei-Chin, Rzepa, Sylwia, Džugan, Jan, Sedláček, Radek, Daniel, Matej
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-03-2022; MDPI
• Subjects: Accuracy; Additive manufacturing; Bulk modulus; Finite element method; Honeycomb structures; Laser beam melting; Mathematical analysis; Mathematical models; Mechanical properties; Metal powders; Modulus of elasticity; Polymers; Powder beds; Stainless steel; Stainless steels; Stiffness; Titanium alloys; Titanium base alloys; United States > US; additive manufacturing; analytical modeling; titanium alloys; laser powder bed fusion; numerical simulation; lattice structures
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma15051838

The study aims to compare mechanical properties of polymer and metal honeycomb lattice structures between a computational model and an experiment. Specimens with regular honeycomb lattice structures made of Stratasys Vero PureWhite polymer were produced using PolyJet technology while identical specimens from stainless steel 316L and titanium alloy Ti6Al4V were produced by laser powder bed fusion. These structures were tested in tension at quasi-static rates of strain, and their effective Young's modulus was determined. Analytical models and finite element models were used to predict effective Young's modulus of the honeycomb structure from the properties of bulk materials. It was shown, that the stiffness of metal honeycomb lattice structure produced by laser powder bed fusion could be predicted with high accuracy by the finite element model. Analytical models slightly overestimate global stiffness but may be used as the first approximation. However, in the case of polymer material, both analytical and FEM modeling significantly overestimate material stiffness. The results indicate that computer modeling could be used with high accuracy to predict the mechanical properties of lattice structures produced from metal powder by laser melting.