Deformation and energy absorption characters ofAl-CFRPhybrid tubes underquasi-staticradial compression

To take into account the lightweight and collision safety of the energy absorber, metal-composite hybrid thin-walled tubes have been widely studied, which combine the low-cost metal and high-strength composites. Therefore, the deformation mechanism and the characteristics of the carbon fiber reinforced plastic wound thin-walled aluminum tube (Al-CFRP) were investigated under radial compression condition. Firstly, aluminum tubes, CFRP tubes, and four winding angles of Al-CFRP hybrid tubes (27 degrees, 45 degrees, 74 degrees, 90 degrees) are experimentally analyzed. The contrastive results show that the stability and energy absorption of the Al-CFRP hybrid tube are improved and the winding angle is one of the important factors that affects the radial compression performance of the hybrid tube. And then based on the hybrid model, some theoretical relations are derived to forecast the initial collapse force and energy absorption quickly. The theoretical analysis shows that the radial force on the hybrid tube during the compression is also dependent on the thickness ratio of Al-CFRP layers complicatedly except the winding angle. Therefore, the effects of the winding angle (0-90 degrees) and thickness ratio of Al-CFRP layers (0.25-3.5) on the radial compression performance are investigated. The theoretical predication results show that the hybrid with the winding angle of 90 degrees and thickness ratio of Al-CFRP layers of 0.25 performs over six times of the initial collapse force than the Al tube. Finally, the simulated model based on ANSYS and LS-DYNA is established to explain the reason for the better radial compression performance (A5C10S90) and the deformation mechanism of the hybrid tube, through the stress analysis of inner Al tube, inner CFRP layer, and outer CFRP layer, respectively. It is found that the Al-CFRP hybrid tube (especially 90 degrees) under radial compression shows better bearing capacity which represents the higher initial collapse force, total energy absorption and specific energy absorption, due to the supporting of the inner Al tube and the protection of the outer CFRP tube.