3D−Printed Gradient TPMS Sandwich Structures: A Study on Bending Performance

Triply Periodic Minimal Surface (TPMS) sandwich structures are excellent lightweight load−bearing structures, yet existing 3D printing solutions focus on homogeneous TPMS lattices or their compressive behavior, lacking research on gradient−thickness TPMS core flexural performance. This study designs and fabricates three gradient TPMS core sandwich structures via SLM 3D printing, systematically investigating their bending performance, failure mechanisms and energy absorption through three−point bending tests and validated finite element models (deviation < 7.9%). We reveal the gradient coefficient’s regulatory effect on different TPMS topologies, propose a z−axis gradient−thickness design to synergistically optimize local stiffness and global lightweight, and establish accurate performance prediction models. Compared with conventional 3D−printed structures, the proposed gradient TPMS structures exhibit superior bending stiffness, peak load and energy absorption, with flexural performance flexibly tunable via gradient coefficients. This work fills key research gaps and provides a novel, efficient design approach for high−performance lightweight structures in aerospace and rail transportation.