Enhanced compressive and energy absorption properties of braided lattice and polyurethane foam hybrid composites

A B S T R A C T Ultralight structures with excellent specific mechanical properties have been of great interest in the field of transportation. In this study, a new ultralight hybrid material composed of braided lattice (BL) composite tubes and polyurethane (PU) foam was developed. First, BL preforms were produced using a braiding process, and BL composites were subsequently manufactured by resin impregnation and curing. The BL composites were inserted into a PU foam to make a hybrid composite. The compressive behavior of these hybrid composites was experimentally characterized, focusing on the effect of the number of BL layers and their cross-sectional shapes and perimeters on the energy-absorbing behavior. Furthermore, finite element (FE) modeling was conducted to investigate the energy absorption mechanism in the hybrid composites. A good correlation between FE modeling and experimental results was achieved, indicating that the hybrid composites exhibited significantly improved energy absorption properties due to the synergistic effects between foam and BL, outperforming similar ultralight cellular structures in terms of crashworthiness.