Challenges of Compression Test Simulations of a Resin-Filled Auxetic Polylactic Acid Structure

Auxetic materials have recently attracted particular interest due to their wide range of functional applications, especially in smart devices and implants. Characterized by a negative Poisson’s ratio, auxetic materials subjected to tension expand in the transverse direction of the load, while if subjected to compression, undergo shortening in the direction transverse to the load. This study presents the identification and analysis of a material finite element model capable of simulating the behavior of auxetic structures. A uniform pattern of auxetic cells formed by “reentrant bars” constitutes the macromaterial with adjustable mechanical properties according to the angle of the struts. The auxetic structure is first investigated in compression and then impregnated with an epoxy resin to achieve higher levels of energy absorption capacity. By comparing the numerical results obtained with the available experimental data, the challenges and a strategic roadmap to achieve accurate prediction of the mechanical behavior of resin-filled auxetic material are established.