  An orthotropic metamaterial is composed of elements arrayed periodically in
space. The element includes two cuboid structures. The first structure is the
basic structure of the element, and the second structure is the transformation
of the first structure of the element. The first structure of the element is a
cuboid structure composed of 24 bars connected by 8 nodes, and the second
structure of the element is a cuboid structure composed of 36 bars connected by
14 nodes. This metamaterial has 6 independent elastic constants, so there is a
large degree of freedom in material design. Using a simple universal design
method, a metamaterial with tailored elastic constants can be designed.
Therefore, it has great application value in the fields of mechanical
metamaterials, elastic wave metamaterials, acoustic metamaterials, and seismic
metamaterials, and has also laid the foundation for realizing the dream of
controlling elastic waves, acoustic waves and vibrations.
