Evaluation of Flexural Properties of Auxetic Core Sandwich Beams under Three Point Bending Test

Using of lattice cores in the design and construction of sandwich structures is common way to reduce the weight of the structures while retaining a significant amount of their mechanical properties compared to bulk and integrated structures. Since, it is important to choose the constructive geometry that has the best expected mechanical properties. In recent years, auxetic core lattice structures have been extensively studied because of their unique characteristic of negative Poisson’s ratio. In this study, the mechanical properties and deformation behavior of sandwich beams with auxetic cores was investigated. Various sandwich beams with different cellular cores were designed and fabricated via fused deposition modeling (FDM) process. Three point bending tests were conducted on additively manufactured specimens to evaluate their flexural stiffness, energy absorption, etc. It was found that the core geometry of the sandwich structures has a remarkable effect on the energy absorption and other mechanical properties as well as on their deformation modes under loading.