Mechanical Response of Gradient Lattice Structures Based on Topology Optimization

Lattice structure has the characteristics of lightweight, crashworthiness, and better energy absorption capabilities. With the advancement of additive manufacturing technologies, preparing complex lattice structures has become possible. In this study, some novel lattice structures are designed by topology optimization based on the inspiration of the triply periodic minimum surface lattice structures. The different volume fraction lattice structures are combined into four gradient lattice structures (GLSs): unidirectional GLS, bidirectional increasing GLS, bidirectional decreasing GLS, and none GLS (NOGLS). Subsequently, selective laser melting is employed to manufacture the designed lattice structures. Experiments and finite‐element simulation analysis are utilized to evaluate the mechanical performance and collapse patterns of lattice structures. In the results, it is shown that NOGLS has a higher modulus of elasticity and greater load‐bearing capacity for the same relative density. Furthermore, the energy‐absorbing properties of the dot‐matrix structure are significantly improved by a rational density design strategy. This work is valuable for improving the energy absorption performance of structures.