(a) Some representative unit cells in the 2D and 3D SGDs. (b) The sample generation process. (c) The architecture of the GCNN model and actual values versus the predicted values: (d) volume fraction, (e) |$\mathbb {E}_{11}^{\rm H}$|⁠, (f) |$\mathbb {E}_{12}^{\rm H}$|⁠, (g) |$\mathbb {E}_{22}^{\rm H}$| and (h) |$\mathbb {E}_{33}^{\rm H}$| in the effective elastic tensor.