Effect of printing path on compressive properties of 3D printed continuous fiber composite negative Poisson's ratio structure

Abstract

AbstractIn this work, continuous fiber reinforced thermoplastic negative Poisson's ratio structures (CFNPRSs) with rotating squares are fabricated by 3D printing based on a symmetrical orthogonal and one‐stoke path planning method. The influences of the printing path on the Poisson's ratio, elastic modulus and energy absorption of the structures under compression are systematically researched. The distribution of continuous fiber at the hinge has a great influence on the compression behavior of the structures. As the number of cross laps of continuous fibers at the hinge increases, the negative Poisson's ratio effect decreases while the elastic modulus and energy absorption increase. The printed CFNPRSs with no cross lap have the most obvious negative Poisson's ratio effect, with an average Poisson's ratio of −0.61. A comparative study on Poisson's ratio of the 3D printed polylactic acid negative Poisson's ratio structures (PANPRSs) is carried out, and the results show that the PANPRSs cannot achieve the negative Poisson's ratio effect because the insufficient stiffness of the printed rotation units violates the rigid assumption in theoretical model. Furthermore, the printed CFNPRSs with a lower relative density of 0.18 has an even better negative Poisson's ratio effect than the existing fiber‐reinforced auxetic structures fabricated by 3D printing. This work can provide a significant reference for the preparation of lightweight functional structures using 3D printing.Highlights The CFNPRSs with rotating squares are prepared by 3D printing technique. The path planning of the fiber at the hinge affects the properties of CFNPRSs. The negative Poisson's ratio of CFNPRSs is more obvious than that of PANPRSs. The relative density and Poisson's ratio of CFNPRSs have obvious advantages.