Abstract:
This study aims to explore the crushing deformation characteristics and underlying energy dissipating mechanisms of carbon-fibre-reinforced plastic (CFRP)-aluminum-aluminum foam hybrid tubes under both axial (0°) and oblique (10°) loads. Quasi-static compressive tests for net CFRP (CF) tubes, net aluminum (Al) tubes, net aluminum foams (Af), Al-Af hybrid tubes and CFRP-Al-Af hybrid tubes were performed first. The energy absorptions of the Al-Af hybrid columns are always higher than that of the sum net parts under loading angles of 0° and 10°; the energy absorption of the CF-Al-Af hybrid columns reduces under a 0° loading angle while improves remarkably under a 10° loading angle compared with the sum of net parts. Next, numerical models for these hybrid tubes and the corresponding net parts were developed in LS-DYNA, and numerical results indicate that the energy absorption improvement of Al tubes promotes the load-carrying enhancement of Al-Af and CF-Al-Af hybrid tubes, because the Al tubes in hybrid happen more stable symmetric deformation compared with the “symmetric-diamond” hybrid deformation of the net Al tubes; whereas the energy absorption reductions of external CF tubes primarily decrease energy absorption of CF-Al-Af hybrid tubes, because the CFRP tubes in the hybrid occur axial splitting failure due to compressions of inner Al tubes. Finally, the analytical models on mean crushing forces for CF-Al-Af hybrid columns and corresponding net components under axial load were developed, and the results indicate that the developed analytical models can better predict the mean crushing forces of both hybrid columns and net parts.