Hierarchical Deformation Mechanisms and Energy Absorption in Thin-Walled Lattice Composite Structures

Lightweight thin-walled tubes and lattice structures play a vital role in aerospace and transportation due to their high strength-to-weight and stiffness-to-weight ratios, as well as superior energy absorption (EA) capabilities. Laser powder bed fusion (LPBF) technology facilitates the rapid fabrication of complex structural components, owing to its unique manufacturing advantages. This study reengineers traditional thin-walled tube structures by integrating composite design strategies with advanced additive manufacturing to enhance their EA performance. By integrating classical lattice structures with thin-walled tubes, a series of thin-walled lattice composite (TWLC) structures were fabricated via LPBF technology. Mechanical tests and computational simulations demonstrate the proposed designs offer tunable deformation behavior, mechanical strength, and EA. Modifying key lattice parameters alters the deformation participation of the lattice within the TWLCs under compression, leading to significantly enhanced EA performance. Compared to standalone thin-walled structures, TWLCs using a body-centered cubic lattice show an increase in EA of 232.2%, while those using a simplified face-centered cubic lattice show an increase of 439.2%. These findings demonstrate that tailored TWLC designs can achieve customizable mechanical and energy-absorbing properties, laying a foundation for the development of next-generation composite energy-absorbing structures to meet diverse engineering demands.