Auxetic structures in civil engineering applications: Experimental (by 3D printing) and numerical investigation of mechanical behavior

Abstract

Auxetic materials are a group of metamaterials that have a negative Poisson's ratio. The most important advantage of auxetics over conventional materials is higher energy absorption. Consequently, in Civil Engineering, a wide range of applications may be considered for auxetic materials including energy absorber structural elements. In this study, two auxetic structures named re-entrant and arrowhead were selected along with the conventional honeycomb structure to investigate the effect of the negative Poisson's ratio on their mechanical behavior. These structures were produced utilizing a fused deposition modeling (FDM) 3D printer. Energy absorption was investigated numerically and experimentally. In order to increase the accuracy of the numerical study, ductile damage for the material was considered. The results showed that the ultimate forces of the re-entrant and arrowhead structures were increased by 125 % and 164 %, respectively, compared to the honeycomb structure. Furthermore, the amount of energy absorption of the re-entrant and arrowhead compared to the honeycomb structure increased by 47.4 % and 176.8 %, respectively. The rate of specific energy absorption in the two mentioned auxetic structures compared to the non-auxetic structure improved by 20.9 % and 53.5 %, respectively.

Keywords

• Negative Poisson's ratio
• Auxetic materials
• Auxetic structures
• Energy absorption
• Additive manufacturing
• Numerical simulation