Design of mechanical metamaterial with controllable stiffness using curved beam unit cells

摘要

In this paper, a novel mechanical metamaterial with controllable stiffness is proposed based on the structural topology and rational design of curved beam unit cells. First, both straight and curved beams are mechanically analyzed, and the corresponding stiffness of these two beams is compared. Second, various curved beam unit cells are presented based on fractal geometries, and lattice structures assembled from curved beam unit cells are optimally designed and precisely fabricated by means of 3D printing techniques. Finally, multi-layered mechanical metamaterials are proposed and mechanically tested, which exhibit advantages of improved specific stiffness and reduced spatial volume. The theoretical and experimental results are verified using the finite element method (FEM). This study proposes a novel design principle for mechanical metamaterials with adjustable stiffness using curved beam unit cells, which can provide a theoretical basis for the development of mechanical metamaterials and present promising potentials in versatile engineering applications.