Study the Impact of Cross-Sections on the Energy Absorption of Architected Materials

Abstract

Abstract Advances in additive manufacturing (AM) facilitate the fabrication of as-designed architected metamaterials with complex cellular structures. The mechanical properties of these materials can be tailored by their design, i.e., the geometries of the cellular structures, which results in a design-by-demand paradigm and can be employed in a broad range of tasks such as lightweight and energy absorption applications. Despite the extensive studies on designing the geometries of cellular structures, limited works have investigated the impact of cross-sections on the final properties of architected materials. The cross-section is critical since the cellular structures are connected with repeated unit cells, and detrimental stress concentrations are found at all intersections of structural members, which leads to low strength and poor recoverability. In this work, we investigate how the cross-sections of cellular structure affect its energy absorption performance. Specifically, we studied both bending and stretching-dominated cellular structures: five typical strut-based cells were chosen, and each structure is designed with four different types of cross-sections — circular, square, diagonal-square, and rectangular. The structure specimens are printed with lab-developed stereolithography (SLA) printer. Physical compression tests are conducted, and the impacts of cross-sections on final properties are compared and discussed. Designed strategies based on the experimental results are summarized.