The study on the crashworthiness behavior of hybrid AL/GFRP tubes subjected to impact load

The objective of this research is to investigate the behavior of hybrid AL/GFRP tube due to an axial impact loading. The effect of the number of GFRP layers, fiber angles and stacking sequence on collapse behavior of structure was focused. The specimens were made from cylindrical aluminum tube with the diameters of 25.39, 30.48, 38.10 and 45.72 mm, and the thickness of 1.20 mm and 100.00 mm long. They were wrapped with 1-, 2-, 3-, and 4-layer of GFRP to form hybrid tubes. The specimens were tested under the impact load using a vertical impact testing machine by dropping a 30 kg hammer at 2.43 m high. The result revealed that AL/GFRP tube could resist more impact load than that of naked AL tube for every case. The maximum load and the mean load of hybrid tubes increased when the number of layers increased, especially for the 3- and 4-layer tubes. For the effect of fiber angle, it was found that the 45 degree fiber did not have a significant effect to structure crashworthy. The 0 and 90 degree fibers were found to be able to significantly promote the crashworthiness capacity of the structure. The stacking sequence of the fiber angle was also found to have an effect on the collapse behavior of the structure as well as on its crashworthiness parameters. Therefore, the crashworthy of specimen may be improved by proper sequence of fiber angles. According to this study, the recommended pattern of AL/GFRP tubes are [0/0/90], [0/90/90] and [0/0/90/90].