Improving the energy absorption capacity of bending-dominated additively manufactured polylactic acid (PLA) lattices

Abstract

This study aims to investigate the energy absorption performance of three bending-dominated lattice structures including quad-diametral (QD), quad-diametral-line (QDL), and dodecahedron (DO)). Compression test specimens with these three lattice types were manufactured using the material extrusion additive manufacturing technique with PLA material. The specimens were manufactured with different sets of values of the print temperature, layer thickness, and line width to identify their effect on the energy absorption performance. Taguchi's method was utilized for this purpose which revealed that the temperature is the most effective and its optimized value is 225 & DEG;C. It was also found that the energy absorption performance of the DO lattice is superior to that of QD and QDL lattices. In the following set of experiments, the print temperature was fixed to its optimized value (i.e. 225 & DEG;C), and another process parameter (i.e. print speed) along with layer thickness and line width were investigated among eight different groups of DO lattices. Numerical investigations were also performed and validated based on the experimental results. Parametric studies were also done for the DO lattice to improve its energy absorption performance by changing the strut diameters and introducing grading to the struts at each lattice cell.