Optimizing the specific mechanical properties of lattice structures fabricated by material extrusion additive manufacturing

Abstract

Lattice-structured materials are becoming increasingly adopted for impact absorption and load-carrying applications. This study presents the design of experiments approach for examining the mechanical performance of the Schwarz Primitive (SP) lattice structure and the body-centered cubic (BCC) plate lattice in order to optimize their design for material extrusion additive manufacturing. The present study investigates the effect of varying the design parameters (unit cell length, shell thickness, relative density) of these structures on tailoring their specific mechanical properties. This study explores the answers to two major research questions: Does varying the unit cell length of lattice structures affect their specific energy absorption (SEA)? Does varying the relative density of lattice structures affect their specific compressive modulus? The Analysis of Variance indicated that the relative density of the lattice structures is the statistically significant design factor when considering the improvement of SEA. Furthermore, the unit cell length of the lattice structures is the statistically significant design factor when considering the improvement of the specific compressive modulus. It was found that the BCC plate lattices outperformed the SP lattice structures of the same relative density in terms of SEA and specific compressive modulus. The Finite Element Analysis software Abaqus was utilized to regenerate results of the quasi-static compression experiments. Once the numerical model was validated, it was then used to predict the mechanical properties of unprintable and untested body-centered cubic plate lattices.