Fig. 4: Mapping between extreme mechanical properties to anisotropy index.
From: Mining extreme properties from a large metamaterial database
A Anisotropy index ASU versus Ex/Ey and νyx/νxy with their projections on three planes. The colors of the scatters represent the intervals of ASU. The conditions for anisotropy and isotropy are ASU > 10−3 and ASU ≤ 10−3, respectively. B Floating columns of the range of ASU for eleven groups and classic metamaterials. The metamaterials with the highest and lowest ASU in the groups pg and pm are identified. The classic metamaterials with the highest and lowest ASU are marked for comparison. C ASU versus shear modulus G. ASU is divided into three areas: (I) extreme, (II) intermediate, and (III) low ASU, to describe the aggregation along the vertical direction of the scatters. The metamaterials are aggregated into three clusters based on the (i) low, (ii) intermediate, and (iii) extreme values of G. The boundaries of these regions (dashed line) are at ASU = 106 and ASU = 10−3. D Examples of metamaterials with various combinations of anisotropy index and shear modulus. The double central reflection in the orthogonal directions notably enhances shear resistance, as demonstrated by the group cmm, while the single reflection results in extreme anisotropy and low G. E Anisotropy index versus νxy and νyx, and their projections on three planes. The range of νxy and νyx is limited to -0.490 ~ + 0.510 for mining isotropic bi-mode. F Examples of isotropic bi-mode metamaterials in groups p4g and pmm. Metamaterial, pmm_3044_4Eq_8Strut_8092, simultaneously exhibits outstanding effective Young’s moduli and isotropic bi-mode. Source data are provided in the Source Data file.
