Study of Energy Absorption Characteristics and Deformation Mechanism of Stretching-Bending Synergistic Lattices Under Dynamic Compression

The 3D lattice structures have the characteristics of lightweight and high strength, showing good energy absorption characteristics under impact loads. Herein, stretching-bending synergistic lattices are constructed, with the macroscopic backbone in the stretching-dominated configuration and the mesoscopic cells in the bending-dominated configuration. The lattices organically combine the two deformation mechanisms of stretching dominant and bending dominant to exhibit high specific strength and excellent specific energy absorption. The particular deformation model and energy absorption characteristics of the stretching-bending synergistic lattices are analyzed. The dynamic compression response of the structure is found to have a unique stress climbing mechanism, which is the critical factor in enhancing its energy absorption ability. The backbone is the main part of structural energy absorption. By changing the relative density of the backbone, the yield strength and specific energy absorption of the stretching-bending synergistic lattices can be increased by more than 78% and 142%, respectively, than the uniform lattices with the same relative density. The hierarchical structure of the stretching backbone and bending cells provides a new approach for the design of impact-resistant structures.