Methodology for modelling and simulation of tailored 3D functionally graded auxetic metamaterials

Abstract

The description of methodologies for modelling auxetic structures with functional gradient and simulating their behaviour under loading is lacking in the literature, despite an increase of the interest in auxetics and the quantity of experimental data on these structures. This work proposes a method that allows modelling of tailored complex functionally graded auxetic structures, achieved through modifications in the equations defining the basic surfaces that characterize the aforementioned structures. In this method, the simulation studies were performed by means of the finite element method. To showcase the capabilities of this method with complex geometries, the gyroid surface was the chosen example from which to form the auxetic structures. The study was performed on geometries with different gradient types and steepness’s to obtain comprehensive data that allows to infer on the accuracy of the method. The obtained results demonstrate that even for large deformations (> 10%), the simulations concur with the experimental results. The good agreement between computational and experimental results points out the validation of the proposed methodology and the further application for various auxetic structures.