Dynamic Characteristics of Functional Gradient Lattice Structure of Triply Periodic Minimal Surface

A functional gradient lattice structure based on triply periodic minimal surface (TPMS) was designed by implicit function method, the mapping relationship between geometric parameters and relative density was established, and the gradient index was introduced to control the density distribution of the lattice structure. The equivalent mechanical parameters were calibrated by finite element simulation and uniaxial compression test, the dynamic model of TPMS functional gradient lattice structure on the basis of the principle of minimum potential energy was established, and the model was solved numerically. The model was verified by finite element simulation and test modal analysis. The dynamic characteristics of the lattice structure were analyzed by the established dynamic model. The results show that the relative error between the former four natural frequencies of the TPMS functional gradient lattice structure obtained by the former established dynamic model and the finite element simulation was less than 5%, and the relative error between the two natural frequencies and the test results was less than 6%, indicating the reliability of the established model. The natural frequency of TPMS functional gradient lattice structure increased with the increase of relative density. With the increase of gradient index, the frequency of the xOy plane bending mode (first/third/seventh order) decreased first, then increased and then decreased, the frequency of the xOz plane bending mode (second/fourth/eighth order) and the longitudinal mode (sixth order) decreased.