Inner Design and Strain‐Rate Effects on the Performance of Architected Materials and Interpenetrating Phase Composites: State‐of‐the‐Art Analysis and Perspectives

Architected materials achieve properties infeasible for their monolithic counterparts, with the inner topology and base material, serving as a lever for the desired target performance. The work investigates the influence of the base material, inner topological design, and loading rate on the mechanics of single‐phase architected materials and interpenetrating phase composites (IPCs). Metamaterials additively manufactured with different, widely employed metals, namely steel 316 L, aluminum AlSi10Mg, and titanium Ti–6Al–4V alloys, as well as polymer‐based designs, are considered, along with metal–metal, metal–ceramic, metal–polymer, and polymer–polymer IPCs. Their peak stresses, densification or failure strains, specific energy absorption, and strength are thoroughly analyzed for diverse inner topological patterns, including strut, triply periodic minimal surfaces, and stochastic architectures. Comparative, quantitative insights into the effect of their inner design and loading rate are provided, deriving simplified analytical formulas for the bounds of the stress spaces developed. Their specific strength is assessed, evaluating the significance of relative density and loading rate on the recorded mechanics. Ceramic–metal and metal–polymer IPCs are found to be particularly sensitive to the loading rates applied. Overall, large‐data‐based summarizing performance metrics for the forward and inverse engineering of architected materials are provided, identifying limitations in the current state‐of‐the‐art, while detailing research perspectives.