Quasi-static and dynamic mechanical properties of functionally graded triply periodic minimal surface structures and...

Functionally graded design has proven highly effective in enhancing the mechanical performance of porous structures, yet the influence of nonlinear gradient distributions on the quasi-static and dynamic response of triply periodic minimal surface (TPMS) structures remains insufficiently understood. This study systematically investigates Gyroid TPMS structures with linear and nonlinear (logarithmic, sigmoid, exponential) wall thickness gradients through quasi-static experiments, validated finite element simulations, and analytical modeling. Under quasi-static compression, graded structures exhibit a layer-by-layer collapse mode with localized densification, significantly enhancing energy absorption; the sigmoid gradient achieves the highest specific energy absorption of 13.01 J/g-a 45% improvement over uniform counterparts. The Gibson-Ashby and iso-stress models accurately predict elastic modulus and yield strength for both uniform and graded configurations. Under dynamic impact (10-100 m/s), the exponential gradient structure attains superior specific energy absorption of 24.17 J/g at 100 m/s, with the rigid-perfectly plastic-locking model successfully predicting dynamic plateau stress. These results demonstrate that nonlinear gradient distributions enable precise tuning of mechanical response and energy absorption capacity. When integrated into interior design applications, functionally graded TPMS structures offer unique opportunities for lightweight, impact-resistant architectural elements that combine structural performance with aesthetic expression-providing a foundation for sustainable, multi-functional interior systems.