Mechanical Characterization of Lattice Materials via Additive Manufacturing and Digital Image Correlation Technique

Abstract

The advent of additive manufacturing has sparked a revolution in lattice material research, offering promising applications across diverse industries. However, assessing the mechanical properties of these intricate structures has posed a significant challenge. Ambiguities in plastic material testing standards and the financial hurdles tied to specialized testing equipment have hindered progress. This study presents a simplified, cost-effective methodology employing readily available tools and computational techniques. Our approach utilizes a Formlabs Form 3 Stereolithography (SLA) 3D printer with Formlabs Tough 1500 resin, coupled with the Instron-5944 2kN universal testing system[1]. We meticulously fabricated compression specimens adhering to ASTM standard D695-15[2], then produced hexagonal lattice configurations subjected to compression testing. Accurate displacement and strain measurements were achieved using digital image correlation (DIC) techniques, bolstered by open-source Ncorr software and the Point Track algorithm[3, 4]. One challenge in lattice experiments is creating a reliable speckle pattern on the lattice surface for precise DIC measurements, which we addressed using tattoo papers[5]. To validate our findings, we conducted finite element (FE) simulations of the compression experiments. These simulations closely matched our experimental results, highlighting the reliability of our methodology. In conclusion, our user-friendly approach simplifies lattice material characterization and deepens our understanding of their mechanical behavior. By integrating additive manufacturing, DIC techniques, and FE simulations, our methodology offers an accessible path for advancing lattice material research. It empowers researchers to explore these materials’ mechanical properties without the financial constraints of expensive experimental setups, fostering progress in this field and expanding its industrial applications.