Effective Design of Three New Layered Gradient Lattice Structures and Their Crashworthiness

Gradient lattice structures are gaining increased attention due to better meeting the crashworthiness requirements of lightweight structures. This study explores how cell number, configuration, and diameter ratio affect mechanical properties and energy absorption. Three new types of gradient lattice structures are designed. Initially, the mechanical properties, deformation behaviors, and energy absorption capabilities of gradient lattice structures are analyzed through finite element simulations. Subsequently, gradient lattice structures are fabricated using 316L laser powder bed fusion technology, and quasistatic compression tests are conducted using a materials testing machine to validate the effectiveness of the simulation results. The results show that the inner and outer structure diameter ratio gradient strategy has the greatest influence on the mechanical properties and energy absorption capacity of the lattice structure. Among all the gradient structures, the BSF structure (cell number gradient lattice structure-F) is the optimal structure, whose maximum impact force and total energy absorption are 88.8 and 107.9% higher than those of the conventional uniform JYC structure (uniform gradient lattice structure-C), respectively. The three gradient strategies proposed in this study provide insights into the design and optimization of impact-resistant lattice structures, which can be used as potential materials for future impact-resistant applications.