Mechanical Properties of 3D-Printed Polymeric Cellular Structures Based on Bifurcating Triply Periodic Minimal Surfaces

Triply periodic minimal surface (TPMS) structures hold great potential as mechanical materials due to their exceptional strength-to-weight ratios and energy absorption capabilities. However, the limited number of known structural types poses a barrier to a profound comprehension and utilization of their mechanical properties. Herein, the mechanical properties and deformation mechanisms of eight recently discovered bifurcating TPMS structures characterized by noncubic symmetries are reported. These polymeric metamaterials are fabricated by fused deposition modeling, followed by quasistatic compression tests conducted across multiple loading directions to evaluate their anisotropic mechanical responses. Experimental results show that the bifurcating TPMS structures generally exhibit enhanced strength compared to classical counterparts, particularly in the direction of bifurcating deformation. Additionally, finite-element simulation is employed to simulate the failure behavior and it is found that stress concentration varies in different structures, which is closely related to the geometry types and deformation mechanisms. These results demonstrate the suitability of bifurcating TPMS structures for load-bearing applications and may pave the way for innovative designs and fabrication of efficient lightweight mechanical structures in the future.