Cycle deformation behavior of 3D-printed CF/PEEK honeycomb metamaterials with zero Poisson's ratios

To realize the one-dimensional deformation of morphing wings, zero Poisson's ratio (ZPR) honeycomb metamaterials have become a popular research topic due to their lightweight, low in-plane modulus, and high out-of-plane strength. A ZPR honeycomb metamaterial is designed and prepared from short-cut carbon fiber-reinforced polyetheretherketone (CF/PEEK) by a 3D printer. The mechanical properties of ZPR honeycomb metamaterials were tested to determine their tensile and bending stiffness. The results show that the metamaterial can achieve 62.3% +/- 3.3% in-plane elastic deformation after optimized structure design. At the same time, metamaterial has a certain bending resistance to keep the airfoil from normal buckling deformation. Moreover, a new test method for evaluating the cycle deformation behavior of flexible morphing wings is proposed. The high-speed cyclic tension-compression test showed that H22-t0.6-CT has the best stability, which may be related to its lower porosity (2.15% +/- 0.12%). These results indicate that ZPR honeycomb metamaterials have great application prospects in the field of morphing wings. Highlights center dot The printed CF/PEEK wire is treated as a transversely isotropic material.center dot ZPR honeycomb metamaterial allows for more than 50% in-plane deformation.center dot A new test method to evaluate the cyclic deformation behavior.

Automated summary

ZPR honeycomb metamaterials have become a popular research topic for realizing the one-dimensional deformation of morphing wings due to their lightweight, low in-plane modulus, and high out-of-plane strength. A ZPR honeycomb metamaterial made from CF/PEEK material was prepared by 3D printing and its mechanical properties were tested. The results showed that the optimized metamaterial can achieve significant in-plane elastic deformation and has certain bending resistance. A new test method for evaluating the cyclic deformation behavior of flexible morphing wings was proposed.