Influence of hybrid lattice design on mechanical response, failure behaviour, and energy absorption characteristics

Abstract Hybrid lattice structures have gained a lot of interest for achieving desired physiologic properties such as mechanical performance, anisotropic and energy absorption behaviour. Triply periodic minimal surface (TPMS) lattices, whether with TPMS-TPMS or TPMS-strut configuration are not explored, particularly in terms of deformation mechanisms and failure prediction. In this study, various types of lattice structure (L-SP, L-OCT, L-RE, L-SQ, SP-D and SP-D-SC) were systematically examined at a fixed value of lattice porosity (0.6φ) with respect to compressive response, energy absorption and elastic anisotropy, supported by numerical results. The results demonstrate that compressive strength of 4.5 MPa was better than that of the other two configurations, while the L-SP-0.6φ TPMS-TPMS configuration had the highest compressive peak stress of 9.01 MPa and the best deformation characteristics among the TPMS-strut hybrids, with the L-OCT-0.6φ configuration showing the most stable deformation characteristics. The results obtained from energy absorption analysis revealed that the L-SP-0.6φ had the best energy absorption value of 1.51 MJ/m 3 while L-OCT-0.6φ had the highest specific energy absorption value with minimum fluctuations in stress value. In addition, anisotropy evaluation showed that the stiffness in other directions was significantly altered by hybridization, with the SP-D lattice exhibiting quasi-isotropic behaviour. Customizable hybrid lattice structures can be used to optimize mechanical performance with good support for the design of future scaffolds with superior biomechanical compatibility.