Mechanical characterization and puncture resistance of 3D ‐printed PLA lattice structures

• Published in: Polymer engineering and science Vol. 64; no. 10; pp. 5006 - 5021
• Main Authors: Mani, Megavannan, Murugaiyan, Thiyagu, Shanmugam, Vigneshwaran
• Format: Journal Article
• Language: English
• Published: Newtown Society of Plastics Engineers, Inc 01.10.2024; Blackwell Publishing Ltd
• Subjects: 3D printing; Acid resistance; Additive manufacturing; Analysis; Bend strength; Biomedical engineering; Biomedical materials; Biopolymers; Energy absorption; Failure analysis; Hexagonal lattice; Impact analysis; Impact resistance; Impact strength; Interfacial shear strength; Mechanical engineering; Mechanical properties; Polylactic acid; Shear strength; Specific energy; Stainless steels; Structural design; Tensile strength
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.26897

The increasing application of additivcly manufactured (AM) materials in engineering and biomedical fields highlights the necessity of understanding their mechanical behavior, particularly with complex lattice structures. Polylactic acid (PLA), a popular biopolymer in additive manufacturing, exhibits mechanical characteristics highly dependent on its structural design. This research investigates the quasi-static puncture failure analysis and mechanical characteristics of additively manufactured (AM) polylactic acid (PIA) materials with various lattice structures. The mechanical behavior, including tensile strength, flexural properties, interlaminar shear strength (ILSS), Izod impact resistance, and quasi-static punch shear strength (QS-PSS), was investigated following the respective ASTM protocols. Results indicate a 6% increase in tensile strength, to ca. 28 MPa, for the triangular PLA lattice structure compared with plain lattice structures. In the flexural test, the hexagonal structure showed a 13% increase in bending strength, to ca. 45 MPa, compared with the plain structure. Additionally, the hexagonal PLA lattice structure exhibited a 24% increase in shear strength, to approximately 8 MPa, over the plain lattice structure in the interlaminar shear strength analysis. In the Izod impact analysis, the plain lattice structure demonstrated a 17% increase in impact strength, to ca. 278 J/m, compared with the circular structure. A stainless- steel hemispherical indenter was employed to investigate the quasi-static punch shear behavior (QS-PSS) of different lattice structures. The triangular structure displayed increased total energy absorption capacity and specific energy absorption of ca. 19 J and 0.529 J/g, respectively, compared with other lattice structures. These results are important for the creation of additively manufactured PLA lattice structures, improving the puncture resistance of advanced composites.