Mechanical Response and Crashworthiness of Twisted Primitive Triply Periodic Minimal Surface (TPMS) Lattices

In recent years, triply periodic minimal surface (TPMS) structures have attracted considerable attention due to their excellent mechanical properties, lightweight characteristics, and remarkable potential for energy absorption in various engineering applications, particularly in automotive safety. To address the demand for enhanced energy absorption, a TPMS design strategy incorporating controllable twisting along the build direction is proposed in this study, enabling the regulation of local deformation paths and global absorption responses. Standard Primitive unit cells were constructed using an implicit function formulation, and twisted Primitive (TPS) structures with various twist angles were subsequently generated. TPS specimens were fabricated from 316 L stainless steel via selective laser melting (SLM) to evaluate the influence of twisting features on their mechanical behavior. To systematically elucidate the role of twisting in energy absorption, quasi-static compression tests were conducted and complemented by finite element simulations to analyze deformation modes and absorption characteristics under different twist angles. The results indicate that the twisting strategy significantly enhances the energy absorption capability of the Primitive structure. Compared with the standard Primitive configuration, TPS structures exhibit a higher specific energy absorption and a more stable progressive collapse mode under compression. In particular, increasing twist angles lead to notable improvements in both absorption efficiency and deformation controllability. Overall, the proposed controllable twisting design provides an effective approach for improving the energy absorption performance of TPMS lattices, offering theoretical guidance and technical support for their application in automotive passive safety and other energy-management systems.