Regulated multi-scale mechanical performance of functionally graded lattice materials based on multiple bioinspired patterns

Functionally graded lattice material (FGLM) possesses great architectural flexibility and performance combinations that do not occur in uniform lattice structures. The regulation effect of highly diversified FGLM design strategies on multi-scale mechanical performance still remains to be revealed. Here, FGLMs with diversified topology features were proposed by using a design strategy that learns from the natural bone remodeling process. Shell-based and strut-based triply periodic minimal surfaces (TPMSs), which respectively act as secondary phase and matrix phase, are coupled together by referencing natural systems. Multi-scale investigation on the linear, surface and chiral strengthening TPMS-FGLMs substantiates the highly tunable mechanical performance. The mechanical performance spatiotemporal asynchrony caused by predetermined secondary phase significantly alters the post-yielding and failure behavior, further restricts the failure band propagation and catastrophic collapse. Secondary phase distributed in cross-like pattern provides balanced mechanical strength and energy absorption efficiency. The present study enriches the FGLM design methodology and indicates a tempting prospect for mechanical performance regulation.