Design and performance simulation of hybrid hemp/glass fiber composites for automotive front bumper beams

This study investigates the use of hemp/glass fiber reinforced epoxy composites for designing automotive front bumper beams, focusing on crashworthiness and pedestrian safety. The composite bumper beam model is evaluated through low- and high-velocity crash simulations and pedestrian leg form impact tests using LS-DYNA software. Optimal stacking sequences are analyzed, with high-strength glass fibers positioned on the outer layers to bear impact loads and low-density hemp fibers in the middle. The hybrid hemp (H)/glass (G) fiber composite laminate can absorb up to 90% of the impact energy absorbed by a glass fiber composite, with a ±45° fiber orientation, showing exceptional energy absorption capabilities. The [G(±45°)₄, H(±45°)₄]_S composite bumper beam offers superior impact performance, safety, and a weight reduction of 49.2% compared to a commercial steel bumper beam. This study highlights the potential of natural fiber composites as sustainable alternatives in automotive design.