On crushing characteristics of different configurations of metal-composites hybrid tubes

Metal/composites hybrid structures, which combine low-density composites with low-cost metallic materials, are gaining increasing attention for meeting higher and higher requirements of lightweighting and crashworthiness in automotive and aerospace engineering. This study explores the crushing characteristics involving energy absorption and damage behaviors of three different configurations of hybrid aluminum/CFRP under quasi-static axial loading. For a comparative purpose, empty aluminum tube and CFRP tube were tested as well. Based on the experimental results, effects of different configurations on crashworthiness characteristics were studied; and it was found that the hybrid tube H-I (i.e. the aluminum tube internally filled with a CFRP tube) offers the best results. Finally, the advantages of hybrid tube H-I were further investigated from the perspectives of cost and lightweight by using the analytical models derived. It was found that for the same energy absorption, hybrid tube H-I saves the cost by 32.1% compared with the pure CFRP tube, and leads to the weight saving of 33.6% compared with the pure aluminum tube. Such a hybrid structure would be of considerable potential to be used as an efficient energy absorber.