Resin-Reinforced Auxetic Structures with Re-Entrant Struts for Improved Energy Absorption

This study aims to improve the energy absorption and mechanical properties of auxetic structures by optimizing their design and analyzing the influence of different resin matrices in composite fabrication. Auxetic materials exhibit unique deformation behavior due to their negative Poisson's ratio, making them promising for energy absorption applications. However, their practical implementation is often constrained by their intrinsic mechanical properties, particularly their strength under realistic loading conditions. This research investigates the effect of resin matrix selection on the energy absorption capacity, Young's modulus, and yield strength of auxetic composites. A systematic experimental campaign was conducted, subjecting auxetic structures reinforced with various resin matrices to compressive loading. The results indicate that embedding the auxetic structure within a resin matrix significantly enhances energy absorption compared to pure resin samples. Notably, vinylester resin composites exhibited the highest Young's modulus, yield strength, and energy absorption capacity. This superior performance is attributed to the synergistic interaction between the auxetic structure, which efficiently distributes stress, as well as the intrinsic toughness and load-bearing capacity of the vinylester resin. These findings contribute to the optimization of auxetic composites for energy absorption applications and the development of high-performance materials for impact mitigation in aerospace and automotive industries.