Design-governed scaling laws and deformation transitions in anisotropic IWP-based cellular nanomaterials

• - IWP nanostructures transition from bending to stretching deformation modes. • - Scaling exponents for stiffness and strength decrease with higher aspect ratios. • - Large aspect ratios enhance stiffness but lead to rapid strain softening. • - Small aspect ratios promote stable plastic flow via gradual defect propagation. • - Dislocation kinetics and stacking faults drive the atomistic plasticity modes. The exceptional mechanical capabilities of three-dimensional triply periodic minimal surface nanostructures offer significant potential for developing high-performance and lightweight materials. This study utilizes molecular dynamics simulation to systematically investigate the mechanical properties and design-governed scaling laws of nickel-based I-graph-wrapped package nanostructures by varying both the structural aspect ratio from 0.5 to 2.0 and relative density from 0.2 to 0.9. Results show that Young’s modulus and yielding strength increase significantly with higher aspect ratios and relative densities. Specifically, for uniform structures ( c / a =1.0), the ultimate tensile strength (UTS) increases from approximately 0.66 GPa at ρ r = 0.2 to 6.36 GPa at ρ r = 0.9 . Through the Gibson-Ashby model, this study identifies a critical transition in mechanical regimes. Particularly, for c / a = 1.0 , the scaling exponents for Young’s modulus ( n ) and yield strength ( m ) are 1.90 and 1.50, respectively, aligning with classical theoretical predictions. However, as the aspect ratio increases from 0.5 to 2.0, n decreases from 3.23 to 1.38 and m drops from 2.41 to 1.20, indicating a fundamental shift from bending-dominated deformation to stretching-dominated behavior. Microstructural analysis reveals that structures with a small aspect ratio experience high stress concentrations at strut-node junctions, leading to a low yielding strength yet stable plastic flow. In contrast, configurations with a large aspect ratio exhibit uniform stress distribution and higher strength but are prone to rapid strain softening. These findings provide a robust framework for optimizing geometrical nanostructures to facilitate the design of predictable, lightweight materials for aerospace and automotive applications.