Design and evaluation of TPMS-inspired lightweight metamaterials with tunable quasi-static and dynamic mechanical performance

Metamaterials with lightweight, high strength, and tunable performance hold significant potential for multifunctional and high-performance applications, particularly in terms of load-bearing capacity, energy absorption, and impact resistance. However, as the functional requirements in service become increasingly complex, overcoming the design limitations of fixed-topology metamaterials in achieving multifunctional synergy under varying conditions has become a critical technical challenge. In this study, we designed two types of lightweight metamaterials with dual-tunable parameters and investigated the static compression properties and dynamic impact resistance of AlSi10Mg metamaterials. We also revealed the dominant role of topological features in the deformation mechanisms of metamaterials and the multifunctional regulatory mechanism of rod diameter parameters. The results show that through dual-strut diameter optimization design, the PRST and IRST metamaterials achieved effective broad-range elastic modulus regulations of 0.58–4.12 GPa and 0.66–2.21 GPa, respectively, within low volume fractions of 0.114–0.207 and 0.106–0.191. Under dynamic impact loading, both the PRST and IRST metamaterials exhibited significant geometrically dependent buckling and fracture behavior. Tuning the strut diameter enhanced the specific energy absorption under dynamic loading by 56.2% for PRST and 67.5% for IRST metamaterials, while their static energy absorption capacity was improved by 40% and 102%, respectively. Furthermore, the energy absorption characteristics of the two types of mechanical metamaterials under different strains exhibit different response mechanisms, which is attributed to the difference in their topological characteristics. Moreover, the PRST and IRST metamaterials exhibited tensile-dominant and bending-dominant mechanical behaviors, respectively. Both achieved synergistic optimization of the load-bearing capacity and energy absorption within low volume fractions, breaking through the technical bottleneck of the multifunctional design of lightweight metamaterials restricted by topological features and volume fractions. This study provides a significant theoretical foundation and design guidance for the development of mechanical metamaterials with excellent static and dynamic mechanical properties.