| Abstrakt: |
Safety requirements and lightweight have been the primary considerations in designing automotive parts. The selection of materials with high specific strength, energy absorption, and specific stiffness properties, such as aluminum and fiber-reinforced composites, paves the way to resolving this challenge. This study investigates and compares the energy absorption characteristics and pedestrian protection of the automotive front bumper beam made of aluminum, carbon fiber-reinforced epoxy (CFRE), and glass fiber-reinforced epoxy (GFRE) with the steel counterpart. The baseline steel bumper beam under a high-velocity frontal crash to a rigid wall at 50 km/h was first analyzed using finite element analysis through LS-DYNA. The bumper beams of other lightweight materials were designed with identical energy absorption capacity. They were then assessed through the low-velocity crashes according to UN-ECE R42 regulation and Euro NCAP pedestrian testing protocol. Although the aluminum bumper beam deformed less in crash tests, it possessed the lowest specific energy absorption (SEA) and the highest peak force. The quasi-isotropic CFRE and GFRE composite beams attained higher SEA because the stresses could be efficiently distributed in the beams, as observed from more extensive damage areas, especially in the ±45°-plies. From a proposed effective parameter weighted from the peak force, maximum deformation, energy absorption, mass, and cost, the GFRE bumper was recommended for modern car bumper beams. The optimal design of the GFRE bumper beam could substantially improve crashworthiness compared to the baseline steel beam with a weight reduction of 67.7%, a 101.8% increase in the SEA, and a 59.8% decrease in the peak force. Furthermore, the pedestrian's lower leg protection was further achieved by adjusting the beam's position. [ABSTRACT FROM AUTHOR] |
