Comparative mechanical performance of radially graded triply periodic minimal surface cored sandwich structures

Triply Periodic Minimal Surface (TPMS) lattice structures are regarded as excellent candidates for energy-absorbing applications due to their high strength-to-weight ratio and extensive surface area with tuneable mechanical properties. This paper comprehensively reports the comparative energy absorption behaviour and mechanical response of functionally graded TPMS cored sandwich structures focused on radial grading under quasi-static compression. The sandwich structure comprised two facesheets with a functionally graded TPMS core between them. Five different grading configurations were considered in this study which comprised with radial grading, longitudinal grading and uniform grading. The specimens were additively manufactured using Acrylonitrile Butadiene Styrene (ABS) and were tested under a strain rate of 0.001 s −1 . Numerical simulations were carried out to support the experimental results. The performances were analysed with respect to force-displacement responses, front-face deformation profiles and fracture details along with energy absorption properties. Further insights into internal stress distributions and deformation mechanisms were examined utilising the validated numerical model. The results revealed that, the Negative Radially Graded (NRG) configuration which is bio-inspired by the human bone architecture, showcased the highest specific energy absorption with nearly 20% and 5% respective enhancements compared to the uniform and longitudinally graded counterparts, highlighting the emergence of radially graded TPMS cored sandwich structures as excellent candidates for energy-absorbing applications.