“…Thus, reduced-order models have been actively studied. Some important reduced-order methods include the Voronoi cell method (Ghosh and Moorthy, 1995), spectral method (Aboudi, 1982), network approximation method (Berlyand and Kolpakov, 2001), fast Fourier transforms (Moulinec and Suquet, 1998), mesh-free reproducing kernel particle method (Chen et al, 1996), finite-volume direct-averaging micromechanics (Cavalcante et al, 2011), transformation field analysis (Dvorak, 1990), methods of cells (Paley and Aboudi, 1992), methods based on control theory including balanced truncation (Moore, 1981), optimal Hankel norm approximation (Glover, 1984), proper orthogonal decomposition (Krysl et al, 2001;Yvonnet and He, 2007), data-driven-based reduced-order methods (Bhattacharjee and Matouš, 2016;Fish et al, 2018;Le et al, 2015), and non-uniform transformation field methods (Fritzen and Böhlke, 2011;Michel and Suquet, 2004). Principally, the multiscale simulations could be based on a combination of these two categories, using concurrent and information passing methods in a hybrid way.…”