Mechanical Properties and Energy Absorption in Body-Centered Offset BCC Lattice Structures

Light-weight lattice structures is widely used to impact-resistant energy-absorbing devices due to high strength, stiffness, and energy absorption. The present study derives inspiration from the porosity gradient lattice structure, and mechanical properties and energy absorption of the body-centered cubic (BCC) lattice structures is carried out by adjusting joint stiffness to enhance performance. Specific energy absorption, stiffness and plateau stress of the equidistantly offset BCC lattices are superior to those of uniform BCC lattices and body-centered linearly offset BCC lattices based on the exhibition of numerical simulations. Finite element analysis further examines the effects of body-center offset direction and magnitude on the compressive properties and specific energy absorption of the BCC lattices. The results indicate that body-center shifts in the compression direction exert a more substantial influence on stiffness and strength. As the offset increases, the strain-hardening effect in the BCC lattice structures becomes more pronounced. Compared to the uniform BCC lattice, a BCC structure with a body-center offset of 1 mm along each of the three-dimensional coordinate axes exhibits a 169% increase in specific energy absorption. Additionally, the plateau stress derived from plastic hinge theory for eccentric BCC lattices offers an effective approach for designing high-performance structures.