A PARAMETRIC STUDY OF ENERGY ABSORPTION EFFICIENCY IN POLYMERIC 3D PRINTED CELLULAR STRUCTURES

Abstract

Cellular structures are regarded as excellent candidates for lightweight energy-absorbing applications in various industries such as vehicles, sports, and packaging. The cellular design should be optimized for a purpose since the geometrical design and configuration of cellular structures are of great significance to their mechanical properties. As additive manufacturing (AM) technology arises, cellular structures can be optimized with high design freedom to achieve the desired energy absorption properties. Numerous design approaches for cellular structures have been proposed to help the manufacturer to fabricate specific energy-absorbing cellular structures. In general, these approaches tend to be focused on the relative density of the structure. This is quite cumbersome to manufacturers since they have to measure each structure's relative density if they want to make the structures that have the desired energy-absorbing capability. This study aims to suggest a parametric design method of the polymeric cellular structures that have the desired energy absorption capability. The flow of this study can be explained in the following four steps. First, two different types of polymeric cellular structures were designed with a wide range of relative densities. Open-cell honeycombs were formed from regular unit cells with a cell wall thickness (t) and cell wall length (L). Three types of lattice structures (kelvin, octagonal, octet truss) were designed with strut thickness (t) and the number of unit cells in a side (N). Second, quasi-static compression tests were conducted to collect energy absorption related data. Third, based on the compression test results, statistical analysis was conducted to investigate the relationship between structural parameters of the cellular structures and energy-absorbing capability factors (efficiency, specific energy absorption, and energy absorption per unit volume). Finally, optimized structural parameters of each cellular structure for vehicle seat application are proposed.