A Finite Element Study on the Effect of Bulk Material on the Auxetic Behavior of Additively Manufactured Three-Dimensional Reentrant Honeycomb

Abstract

AbstractThis study investigates the behavior of three dimensional reentrant auxetic honeycomb made of different bulk materials. The energy absorption capacity of auxetic structure depend on both geometrical properties of the unit cell as well as mechanical properties of the bulk material. Auxetic structures are classified as auxetic foams, 2D auxetic structures, and 3D auxetic structures. Based on the literature survey, 3D reentrant auxetic honeycomb (3DRAH) with a relative density of \(0.16\) were considered for this investigation. The important aspect of this study is to analyze the effect of bulk material and their properties on the performance of 3DRAH. A total of four commonly used plastic materials in additive manufacturing technology were selected as bulk material, they are Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Nylon and High-Impact Poly Styrene (HIPS). All four auxetic models were subjected to quasistatic uniaxial compression using LS Dyna explicit solver. Our numerical simulations showed that at quasistatic loading conditions, the deformation mechanism of 3DRAH is a combination of in-plane bending, out-of-plane bending, and lateral distortion. Moreover, the stress–strain response and the Specific Energy Absorbed (SEA) of the 3DRAH sample are most influenced by the mechanical properties of the bulk material. It is proved through our simulations that as Young’s modulus of the bulk material increases, structural properties like Elastic modulus, Yield stress, Plateau stress and the SEA of the structure increase. No specific correlation was observed between mechanical properties of the material and the densification strain of the structure. We suppose that the densification strain of the structure is rather controlled by the aforementioned deformation mechanism.Keywords3D reentrant auxetic honeycombsFusion deposit modelingFinite element analysisLS DynaSpecific energy absorption