Low-Velocity Penetration Impact Behavior of Triply Periodic Minimal Surface Strut-Based Lattices

Triply periodic minimal surface (TPMS)-based lattices are gaining increasing attention in demanding applications such as aeronautics and automotive. These often involve low-velocity impact loading or the risk of foreign object impact, making it critical to evaluate their performance under such conditions. The specific influence of cell geometry and topology on the penetration impact performance of lattices remains largely unexplored. This gap is particularly evident for TPMS, which strongly diverge from truss-based lattices. This work evaluates five distinct TPMS strut lattice architectures—rigid, compliant, and mixed—under low-velocity penetration impact. Results reveal the pronounced role of architecture and topology in determining penetration impact performance, with absorbed energy differing by up to 12% and damage depths varying by a factor of 2.8 across designs. Notably, no correlation with static compressive behavior is observed, emphasizing the fundamental differences between penetration impact and compression loading. The findings have immediate practical implications for design: for sacrificial, energy-absorbing layers, OCTO and P demonstrate superior performance. Conversely, for prioritizing resilience and structural integrity, gyroid and IWP are more effective. This work underscores the critical role of cell geometry in tailoring the performance of TPMS lattices, offering valuable insights for the design of advanced impact-resistant structures.