Realizing the impact and compressive strengths of an arrowhead auxetic structure inspired by topology optimization

Abstract

Auxetic structures have unique properties wherein the structure collapses inward in the lateral direction when compressed longitudinally and expands in the lateral direction when subjected to longitudinal tensile load. This paper focuses on improving the impact absorption potential of the arrowhead auxetic structure. Topology optimization is performed on this structure to identify areas in the structure where material reduction is possible. The optimized structure inspired the creation of three new variants of the arrowhead structure. These designs are 3D printed using ABS and PLA materials. Compression and impact tests are performed on a drop test rig and a compression test set-up. From the results, an optimal design is obtained that strikes a balance between compressive strength and impact absorption. In addition, a scope for functional structures that are tailor-made for specific applications, based on a trade-off between impact absorptivity and compressive strength, is identified.